Seoul National University Hospital Research Articles

In Vivo Reactive Astrocyte Imaging in Patients With Schizophrenia Using Fluorine 18–Labeled THK5351

ImportanceIn vivo imaging studies of reactive astrocytes are crucial for understanding the pathophysiology of schizophrenia because astrocytes play a critical role in glutamate imbalance and neuroinflammation.ObjectiveTo investigate in vivo reactive astrocytes in patients with schizophrenia associated with positive symptoms using monoamine oxidase B (MAO-B)–binding fluorine 18 ([18F])–labeled THK5351 positron emission tomography (PET).Design, Setting, and ParticipantsIn this case-control study, data were collected from October 1, 2021, to January 31, 2023, from the internet advertisement for the healthy control group and from the outpatient clinics of Seoul National University Hospital in Seoul, South Korea, for the schizophrenia group. Participants included patients with schizophrenia and age- and sex-matched healthy control individuals.Main Outcomes and MeasuresStandardized uptake value ratios (SUVrs) of [18F]THK5351 in the anterior cingulate cortex (ACC) and hippocampus as primary regions of interest (ROIs), with other limbic regions as secondary ROIs, and the correlation between altered SUVrs and Positive and Negative Syndrome Scale (PANSS) positive symptom scores.ResultsA total of 68 participants (mean [SD] age, 32.0 [7.0] years; 41 men [60.3%]) included 33 patients with schizophrenia (mean [SD] age, 32.3 [6.3] years; 22 men [66.7%]) and 35 healthy controls (mean [SD] age, 31.8 [7.6] years; 19 men [54.3%]) who underwent [18F]THK5351 PET scanning. Patients with schizophrenia showed significantly higher SUVrs in the bilateral ACC (left, F = 5.767 [false discovery rate (FDR)–corrected P = .04]; right, F = 5.977 [FDR-corrected P = .04]) and left hippocampus (F = 4.834 [FDR-corrected P = .04]) than healthy controls. Trend-level group differences between the groups in the SUVrs were found in the secondary ROIs (eg, right parahippocampal gyrus, F = 3.387 [P = .07]). There were positive correlations between the SUVrs in the bilateral ACC and the PANSS positive symptom scores (left, r = 0.423 [FDR-corrected P = .03]; right, r = 0.406 [FDR-corrected P = .03]) in patients with schizophrenia.Conclusions and RelevanceThis case-control study provides novel in vivo imaging evidence of reactive astrocyte involvement in the pathophysiology of schizophrenia. Reactive astrocytes in the ACC may be a future target for the treatment of symptoms of schizophrenia, especially positive symptoms.

Abstract PO5-23-04: Clinical utility of sentinel lymph node biopsy in women ≥ 70 years with early breast cancer – an international, retrospective multi-center cohort study

Abstract Introduction Traditionally, sentinel lymph node biopsy (SLNB) has been used to stage the axilla in early breast cancer (EBC) to guide adjuvant treatment recommendations. Following advances in tumor biology understanding, targeted systemic therapies and genomic testing, with increasing de-escalation of axillary surgery, its role may be less critical especially in selected groups of women. Aims Evaluate clinical utility of SLNB in adjuvant treatment recommendations for women ≥ 70 years with EBC. Methods Retrospective cohort study of women ≥ 70 years with cT1-2N0 EBC undergoing primary surgery and SLNB between 01/2017-12/2022 at The Royal Marsden Hospital (RMH), University Hospital Zurich (USZ) and Seoul National University Hospital (SNUH) in the United Kingdom, Switzerland and South Korea respectively. Simple descriptive statistics and non-parametric tests were performed as appropriate. Results A total of 884 patients were included in the analysis, with 584 patients from RMH, 148 from USZ and 152 from SNUH. The median age was 75 (IQR 72-79) years. Most cancers were invasive ductal (82.9%), grade 2 (61.4%), hormone receptor (HR) positive/HER2 negative (82.9%) with a median tumor size of 17 (IQR 4-50) mm. SLNB was positive in 116 (13.1%) patients. Of these 116 patients, 20 (17.2%) had completion ALND; 7/20 had further RT up to levels 3&4 of the axilla. Of these 116 patients, 96 patients (82.8%) avoided ALND; 25/96 had no further treatment, and 71/96 patients had loco-regional axillary RT (8/71 had RT to levels 1&2 and 63/71 had RT up to levels 3&4). As per international guidelines for patients with EBC with 1-2 positive macrometastases on SLNB treated with breast conserving surgery and breast RT, 5/20 could have been spared ALND, and 50/71 axillary RT. Completion ALND was more likely to be performed at SNUH compared to the other 2 units (p< 0.0001). Axillary RT was more likely to be administered at SNUH and less likely at RMH (p< 0.0001). The multidisciplinary team (MDT) recommended adjuvant chemotherapy (AC) in 146 (16.5%) patients and 100 received it. Of those with a positive SLNB (n=116), AC was recommended in 35, and received by 29. Recommendation for AC was significantly associated with younger age (p=0.021), fewer comorbidities (p=0.003), higher tumor grade (p< 0.0001), increased tumor size (p< 0.0001), HR negative status (p< 0.0001), high genomic risk profile (p< 0.0001) and positive SLNB status (p< 0.0001), but not center (p=0.497). A subgroup analysis of 505 patients with cT1N0, HR+/HER2- EBC, representing a more favorable prognosis group, was performed. Here, 52/505 (10.3%) patients had positive SLNB, of whom 11 had no further axillary treatment, 9 underwent ALND and 32 axillary RT, where 4/9 could have been spared ALND and 28/32 axillary RT as per international guidelines mentioned above. AC was recommended in 26/505 (5.15%) women and 23 received it. AC was not recommended in 39/52 (75%) cases, despite a positive SLNB. MDT recommendation for AC was associated with grade 3 (p< 0.0001), multifocal disease (p=0.021), positive SLNB status (p< 0.0001), high genomic risk profile (p< 0.0001), lower age (p=0.044), fewer co-morbidities (p=0.001) and center (p=0.007) with SNUH being more likely than the other 2, but not ethnicity (p=0.130); AC receipt was associated with the same factors except age (p=0.347). Conclusions Real-world data demonstrates axillary overtreatment despite evidence of the safety of de-escalation of axillary management in EBC. Only a small proportion of women ≥ 70 years with EBC had positive SLNB that may influence adjuvant treatment recommendations, especially with favorable prognosis tumors. In such cases, where clinical morbidity and financial burden of SLNB may outweigh the benefits, a nuanced discussion for opting in SLNB rather than routine performance should be considered. Citation Format: Radhika Merh, Denise Vorburger, Ji-Jung Jung, Han-Byoel Lee, Marios Tasoulis. Clinical utility of sentinel lymph node biopsy in women ≥ 70 years with early breast cancer – an international, retrospective multi-center cohort study [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-23-04.

Abstract PO5-09-01: Relative low body mass index (BMI) and fat quantity predicts prognosis better than absolute BMI in hormone receptor-positive, HER2-negative breast cancer

Abstract Purpose: Most existing research about obesity and prognosis in breast cancer patients primarily compares obese and non-obese individuals according to standard body mass index (BMI) categories. With a notably high percentage of Asian patients presenting with young age onset and normal weight, the prevalence of overweight and obesity based on absolute BMI values is lower in Asia (according to WHO guideline, BMI under 18.5 means underweight, and BMI over 25 means overweight). Understanding the impact of relatively low and high weight on prognosis can provide more insightful data than assessments based on absolute BMI thresholds. This study aimed to investigate the impact of relative low/high BMI on the prognosis of breast cancer and to explore the influence of body fat quantity (FQ), which is closely related to BMI. Methods: The study population consisted of 3,663 patients who received surgery for primary breast cancer at Seoul National University Hospital from 2006 to 2015. Pre-treatment BMI was divided into quartiles, defining low-BMI (Q1) as ≤ 21.33, high-BMI (Q4) as > 25.53, and mid-BMI as values between the two. Fat quantity (FQ) was derived from chest CT using the deep learning-based FDA-approved DeepCatch software. It measures the fat volume at the L1 level then divides this value by the square of the patient's height. It was then also divided into quartiles, establishing the definitions of low-, mid-, and high-FQ. The associations of BMI and FQ with distant metastasis-free survival (DMFS) and overall survival (OS) were examined. Results: The high-BMI group demonstrated older median age and higher T and N stages (p< 0.001). The high- and low-BMI groups also showed a higher prevalence of estrogen receptor positive cancer compared to the mid-BMI group. A strong correlation (Pearson correlation coefficient 0.83) was observed between BMI and FQ. In HR-positive, HER2-negative breast cancer, high-BMI patients had a 1.55 times higher risk of distant metastasis (95% CI: 1.15-2.11, p = 0.005), and a 1.78 times higher risk of mortality (95% CI: 1.22-2.58, p = 0.003) compared to mid-BMI patients, while low-BMI patients demonstrated better outcomes regarding DMFS (HR 0.67, p=0.035) and OS (HR 0.59, p=0.04). Comparison of FQ with prognosis revealed that the low-FQ patients exhibited better DMFS (HR 0.59, p=0.005) and OS (HR = 0.44, p=0.002) compared to mid-FQ patients in HR-positive, HER2-negative breast cancer. However, when adjusted for T and N stages, low-BMI patients in the HR-positive, HER2-negative group showed no difference in prognosis from mid-BMI patients but better prognosis compared to high-BMI patients. In contrast, when defined using absolute BMI, underweight patients did not show a difference in DMFS (HR 0.72 vs. normal BMI, p = 0.515) and OS (HR 0.91 vs. normal BMI, p = 0.87) compared to those with normal weight and overweight. The low-FQ group had the best prognosis regarding DMFS (HR 0.66 vs. mid-FQ, p=0.032) and OS (HR 0.50 vs. mid-FQ, p=0.008). Conclusions: Low-BMI is a favorable prognostic factor compared to high-BMI for DMFS and OS in HR-positive, HER2-negative breast cancer. The relative BMI defined according to BMI quartiles was a better prognostic factor than to absolute BMI standards. Investigations with FQ showed similar tendencies, suggesting that low BMI's favorable prognostic influence may be associated with fat. Future investigations should aim to validate these results and delve deeper into the underlying mechanisms. Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Soon Ho Yoon work as chief medical officer in MEDICALIP. This author did not involve data/statistical analysis. Other authors have no competing interest to declare. Citation Format: Eunhye Kang, Ji-Jung Jung, Ik Beom Shin, Hawjeong Lee, Jin Young Byeon, Changjin Lim, Hong-Kyu Kim, Hyeong-Gon Moon, Wonshik Han, Jong-Ho Cheun, Soon Ho Yoon, Han-Byoel Lee. Relative low body mass index (BMI) and fat quantity predicts prognosis better than absolute BMI in hormone receptor-positive, HER2-negative breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-09-01.

Abstract PO5-02-13: Distinct differences in the prognostic implication of tumor size for invasive lobular carcinoma of breast when compared to invasive ductal carcinoma

Abstract Purpose Invasive lobular carcinoma (ILC) is the second common types of breast cancer and its clinicopathological feature and outcomes differ from invasive ductal carcinoma (IDC). However, in terms of survival outcomes, there are conflicting data on the prognostic implication of the ILC when compared to that of IDC. This study aims to evaluate the survival outcomes of patients diagnosed with ILC at single center and compared them with those of IDC. Methods We reviewed the data of the 13,034 IDC patients and 935 ILC patients who were treated between January 2005 and December 2022 at Seoul National University Hospital. We investigated the overall treatment outcomes of two histologic types with a special focus on the tumor size and lymph nodes. Result ILC exhibited distinct characteristics compared to IDC, including a larger tumor size (2.6 ± 1.8 vs. 1.9 ± 1.1 cm, p < 0.001) and a higher hormone receptor positivity (97.4% vs. 79.3%, p < 0.001). Additionally, the presence of lymphovascular emboli was lower in ILC (8.0% vs. 24.6%, p < 0.001). While IDC patients showed slightly better overall survival (OS) than ILC (10-year OS, ILC 89.9% vs. IDC 91.1%, the difference was not statistically significant (p = 0.85). However, distant metastasis-free survival (DMFS) was significantly higher in ILC (10-year DMFS, ILC 93.2% vs. IDC 89.9%, p = 0.001). Age at diagnosis, tumor size, presence of lymphovascular emboli, high expression of Ki-67, and higher pathologic N stage were poor prognostic markers for ILC. Multivariate analysis for DMFS showed that age, high expression of Ki-67 and higher pathologic N stage were poor prognostic markers for ILC. Tumor size was not an independent prognostic factor for DMFS (HR: 0.92, 95% CI: 0.72-1.17, p = 0.491) and for OS (HR: 1.18, 95% CI: 0.99-1.41, p = 0.060) in ILC. Conclusion Our data suggest that the tumor size, which is a well-known prognostic factor in IDC, carries distinctly different prognostic implication in ILC. These observation indicate that adjuvant treatment decisions based on tumor size can be tailored to different histologic subtypes of breast cancer. Citation Format: Ik Beom Shin, Eunhye Kang, Ji-Jung Jung, Hawjeong Lee, Jin Young Byeon, Yunhee Choi, Changjin Lim, Jong-Ho Cheun, Hong-Kyu Kim, Han-Byoel Lee, Wonshik Han, Hyeong-Gon Moon. Distinct differences in the prognostic implication of tumor size for invasive lobular carcinoma of breast when compared to invasive ductal carcinoma [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-02-13.

Abstract PO3-07-09: B3 breast lesions in Asian Centers: malignant upgrade rates and risk factors

Abstract Background Lesions of uncertain malignant potential in the breast (B3 lesions) are composed of a wide spectrum of pathologies with differing risks of breast cancer. With the widespread implementation of screening programs globally, the incidence of these lesions has increased substantially. Asian women tend to have smaller and denser breasts than Western women, making identifying and treating these lesions more challenging. Previous papers quote an upgrade of B3 lesions to malignancy such as ductal carcinoma in situ (DCIS) or cancer at rates of 9.9% to 35.1%. Malignant upgrade on final histology increases patient anxiety and healthcare costs as a second surgical intervention is often required for pathological clearance or lymph node staging. This study aimed to assess the malignant upgrade rate of B3 lesions in Asian women and to evaluate any key factors that may predict the risk of a malignant upgrade. Materials and Methods A retrospective multicentre international study was done on patients at Seoul National University Hospital (SNUH), South Korea, from April 2021 to 2023, and Tan Tock Seng Hospital (TTSH), Singapore, between March 2006 and 2023. Patients who were diagnosed with a B3 lesion on initial breast core needle biopsy and underwent surgical open excision were included in the study. Results A total of 1049 patients were diagnosed with B3 lesions, with 154 (14.7%) upgrading to malignancy. The most common malignancy was DCIS, 118 (76.6%), followed by invasive ductal carcinoma (IDC), 20 (13.0%) and papillary carcinoma, 4 (2.6%). Within the types of B3 lesions, the malignant upgrade rates were found: atypical ductal hyperplasia (ADH), 88/252 (35%); intraductal papilloma (IDP) with atypia, 16/55 (29%); lobular neoplasia (LN), 9/34 (26%); and radial scar (RS), 5/21 (24%). Most patients had both ultrasound and mammographic evaluation, and all lesions in the study were graded BIRADS 4A and above. Univariate analysis showed that age >50 (OR 2.30 [1.61-3.31], p< 0.001), BMI >23 (OR 2.21 [1.20-4.12], p=0.01), post-menopausal status (OR 2.43 [1.34-4.34], p< 0.001), lesion being identified on mammography (OR 3.00 [2.04-4.51], p< 0.001) and presence of microcalcifications on mammography (OR 0.63 [0.41-0.98], p=0.04) were risk factors for malignant upgrade. Conclusion Based on our analysis of Asian women, post-menopausal patients with microcalcifications on mammography and a B3 biopsy result should be treated with a higher degree of suspicion for underlying malignancy. Surgical excision with adequate margins should be routinely considered for B3 lesions such as ADH, IDP with atypia, LN and RS. Avoidance of surgery or vacuum-assisted removal can be considered for younger patients with only ultrasound findings and diagnosis of FEA and IDP. Table 1. Malignant upgrade after excision Table 2. Clinical characteristics of all patients according to malignant upgrade Table 3. Univariate and multivariate analysis for malignant upgrade Citation Format: Wei Wen Ang, Ji-Jung Jung. B3 breast lesions in Asian Centers: malignant upgrade rates and risk factors [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-07-09.

Abstract PO1-27-11: Survival Benefit of Adjuvant Endocrine Therapy in Patients with Estrogen Receptor Low-Positive Breast Cancer

Abstract Background: Estrogen receptor (ER) low-positive (1–10%) breast cancer is a very rare subtype that accounts for only 2–5% of all breast cancer cases and was introduced as a new category in the 2020 American Society of Clinical Oncology/College of American Pathologist Guidelines. There are limited data on the overall benefit of endocrine therapy for patients with ER low-positive cancers. The objective of this study was to analyze the clinicopathological characteristics and treatment patterns in patients with ER low-positive breast cancer and to compare disease-free survival (DFS) between patients who received and did not receive endocrine therapy. Methods: A retrospective search of the prospectively maintained database of our institution identified consecutive women with ER low-positive (1–10%) primary invasive breast cancer who underwent curative surgery at Seoul National University Hospital (Seoul, Korea) between January 2010 and April 2021. Standard immunohistochemical staining techniques were used to assess the level of ER, progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expression, and semiquantitative scores (0–100%) were reported for ER and PR. DFS was defined as the time from surgery to the development of any recurrence and was compared between women who received and did not receive adjuvant endocrine therapy using univariable and multivariable Cox proportional hazards regression. Results: A total of 721 women (median age, 51 years; range, 24–83 years) with ER low-positive cancer were included in the analysis. Overall, 28% (203/721) had AJCC stage I, 42% (304/721) had stage II, and 30% (214/721) had stage III. PR expression was negative (< 1%) in 79% (571/721), low-positive (1–10%) in 12% (90/721), and high-positive ( >10%) in 8% (60/721). HER2 expression was negative in 54% (390/721) and positive in 46% (331/721). Most women (88% [634/721]) received adjuvant endocrine therapy, including all women with PR expression >10%. Of the 661 women with PR expression ≤10%, 87 (13%) did not receive adjuvant endocrine therapy. HER2-targeted therapy was performed in 81% (268/331) of women with HER2-positive cancer. During a median follow-up of 5.7 years, 98 (14%) had recurrence (25 locoregional/contralateral and 73 distant metastases). AJCC stage III (HR, 3.6; 95% CI: 2.4, 5.4; P < .001) and receiving total mastectomy (HR, 1.8; 95% CI: 1.2, 2.8; P = .004) were associated with worse DFS. Receiving adjuvant endocrine therapy was independently associated with better DFS in the entire cohort (HR, 0.46; 95% CI: 0.28, 0.76; P = .002) and in the HER2-negative subgroup (HR, 0.40; 95% CI: 0.22, 0.75; P = .004). In the HER2-positive subgroup, receiving adjuvant endocrine therapy was not significantly associated with better DFS (HR, 0.55; 95% CI: 0.23, 1.32; P = .18). Conclusion: In this large cohort of women with ER low-positive breast cancers, adjuvant endocrine therapy was administered in the majority of cases, including those with PR >10% expression. Receiving adjuvant endocrine therapy was associated with better DFS, especially when HER2 expression was negative. Citation Format: Su Hyun Lee, Han Suk Ryu, Myoung-jin Jang, Kyung-Hun Lee, Han-Byoel Lee. Survival Benefit of Adjuvant Endocrine Therapy in Patients with Estrogen Receptor Low-Positive Breast Cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-27-11.

Abstract PO1-13-07: LIV-1 and Trop2 expression using Immunohistochemistry as prognostic markers in early breast cancer

Abstract Backgrounds: Antibody-drug conjugate (ADC) has emerged as treatment option for breast cancer (BC). The ASCENT and TROPiCS-02 trial of Sacituzumab Govitecan, a Trop2 ADC, gained great success in TNBC and HR+ BC. Other targets, such as LIV-1, are being investigated for TNBC and HR+ BC. The clinical trials of Ladiratuzumab, an ADC of LIV-1 Ab and MMAE, are ongoing. However, unlike Her2 protein, the predictive and prognostic role of LIV-1 and Trop-2 has not been fully investigated. Therefore, we aimed to analyze the relationship between expression level and clinicopathological features and explore the value of the markers among subtypes of BC. Methods: TMA were selected from 1,349 breast cancer specimen of patients who received curative surgery from 2008 to 2012 at Seoul National University Hospital and IHC staining was performed on the TMA using LIV-1 antibody (HPA042377 manufactured by Sigma-Aldrich, St. Louis, MO, dilution ratio of 1:300) and Trop2 antibody(HPA055067, dilution ratio of 1:75). All IHC slides were carefully evaluated by trained pathologists. IHC expression was assessed as intensity (negative:0, weak:1, moderate:2, and strong:3). A modified histochemical score(H-score) was calculated from the intensity multiplied by the percentage of positive cells. Results: A total of 1119 patients from selected samples were included. The median age was 49 (range 25-90). Most patients had early T stage disease (n=513, 569, 29, 7, for pT1, pT2, pT3, pT4, respectively). The percentage of nodal metastasis (N=687 vs 432 in pN0 vs ≥pN1, 61.4 vs 38.6%) and LVI (N= 678 vs 441 in neg vs pos, 60.6% vs 38.6%). 713 pts (63.7%) were HR+ subtype, 200(17.9%) of Her2+ and 206(18.4%) of TNBC. We divided patients into negative/low/high expression groups according to LIV-1 expression by median expression level (cutoff H-score = 100): 479 of 1119 (42.8%) LIV-1-negative; 270 (42.2%) LIV-1-low expression and 370 (57.8%) LIV-1-high. Patients with LIV-1-low or -high tumors showed better DFS (156.2 vs 158.8 vs 159.95 mo for LIV-1-negative, -low, -high, respectively; P=0.0072) and OS(157.6 vs 163 vs 165.4 mo, P=0.0029) . HR+ subgroup, (N= 193 vs 228 vs 354 for neg vs low vs high), followed overall tendency (153.4vs 158.3 vs 159.9mo, P=0.0571 in DFS, 155.6vs160.2 vs165.4mo, P=0.0627 in OS, respectively) In contrast, for patients with TNBC, LIV-1-high expression showed the worst DFS and OS. (N = 183 vs 18 vs 5 in neg vs low vs high group, 159.7 vs 160.7 vs 93.1mo, P value=0.1854 for DFS, 160.8 vs 160.7 vs 93.1 mo, P=0.0334 for OS, respectively) LIV-1 expression failed to prove a prognostic value in Her2+ BC. We also analyzed Trop2 expression by dividing patients into low/intermediate/high by the method used previously in ASCENT trial. 1009 of 1119 (n=341 in low, 363 in intermediate, 305 in high expression) patients had Trop2 expression. There was no statistically significant difference in DFS and OS among all subtypes. In multivariate analysis, neither LIV-1 or Trop-2 had a prognostic role. Conclusion: The analysis of clinicopathological findings of LIV-1 protein indicates their values for prognosis markers, especially in HR+ BC and TNBC. Trop2 expression has no prognostic role in line with previous research. Further studies are warranted to explore targetable biomarkers for the development of appropriate ADCs. Citation Format: Yeonjoo Choi, Han Suk Ryu, Jiwon Koh, Dae-Won Lee, Kyung-hun Lee, Seock-Ah Im. LIV-1 and Trop2 expression using Immunohistochemistry as prognostic markers in early breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-13-07.

Abstract PO5-26-05: Machine learning-based risk prediction for late distant recurrence in young women with estrogen receptor-positive/human epidermal growth factor 2-negative breast cancer

Abstract Background There is a clinical unmet need to predict the risk of late recurrence in premenopausal women with estrogen receptor (ER)-positive/human epidermal growth factor 2 (HER2)-negative breast cancer (BC) who completed endocrine treatment (ET). Previous studies suggest that the CTS5 model, developed using data from cohorts with postmenopausal women and predicts a likelihood of late recurrence after five years of ET, is not highly predictive in premenopausal women. We developed a machine learning-based model predicting the chance of late distant recurrence (DR) using multi-institutional cohorts of premenopausal women with ER-positive/HER2-negative BC who have had no DR for five years from the surgery. Methods The study conducted a retrospective review of patients who underwent primary surgery between 2000 and 2011 at Samsung Medical Center, Gangnam Severance Hospital, and Seoul National University Hospital. The study included premenopausal women with ER-positive/HER2-negative BC aged 45 years or younger, who were treated over two years of ET with or without ovarian function suppression and had not experienced distant recurrence for at least five years following the surgery. Patients who had received neoadjuvant chemotherapy were excluded from the study. The primary endpoint is the area under the curve (AUC) and sensitivity (Recall) of the model predicting late DR after five years from primary operation. A total of nine clinical features, including age, tumor size, the number of positive lymph nodes, nuclear grade (NG), histologic grade (HG), progesterone receptor (PR) status, chemotherapy, extension of ET, and addition of OFS, were utilized for supervised machine learning classification. Results A total of 2,555 patients were included in this study. The median age was 41 (range, 21-45) years. During a median follow-up duration of 130.3 (range, 60.0-257.6) months, 157 women (6.1%) had late DR after five years of breast cancer surgery. Age, NG, HG, tumor size, and the number of positive LNs were important clinicopathologic variables for late recurrence. The treatment variables included chemotherapy, extension of ET, and the addition of OFS. There were 1,951 patients (76.4%) who had adjuvant chemotherapy, 650 patients (25.4%) with extension of ET over 5 years, and 529 patients (20.7%) who underwent addition of OFS. To develop the model, we performed repeated 5-fold cross-validation using a Balanced Random Forest classifier. The AUC and sensitivity of the model with six features, including age, tumor size, the number of positive lymph nodes, NG, HG, and PR status, were 0.705 and 0.768, respectively. When chemotherapy was added to this model, the AUC and sensitivity of the model increased to 0.713 and 0.771, respectively. When two more treatment features, such as ET extension and addition of OFS, were added to the model, the AUC and sensitivity were 0.714 and 0.752, respectively. Conclusions Demographic and clinical characteristics of the patients in this study Table. Citation Format: Dong Seung Shin, Janghee Lee, Jong-Ho Cheun, Jun-Hee Lee, Yewon Shin, Soong June Bae, Eunhye Kang, Sunyoung Kwon, Han-Byoel Lee, Jai Min Ryu, Sung Gwe Ahn. Machine learning-based risk prediction for late distant recurrence in young women with estrogen receptor-positive/human epidermal growth factor 2-negative breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-26-05.

Abstract PO2-13-11: High circulating tumor DNA (ctDNA) concentration was associated with shorter progression free survival in patients with metastatic breast cancer

Abstract Background: Metastatic breast cancer can be classified into different subtypes depending on hormone receptor (HR) and HER2 status. The subtype can change during tumor progression, and repeated biopsy is needed to deliver the most appropriate treatment every time a new lesion is found. It is not always possible to get a new biopsy from metastatic sites, and therefore liquid biopsy using circulating tumor DNA (ctDNA) is suggested as an alternative method to replace conventional biopsy. Methods: We performed a prospective serial collection of 65 ctDNA samples from 17 patients with metastatic breast cancer (mBC) at Seoul National University Hospital from October 2020 to March 2022. We used IMBdx AlphaLiquid®100 method to detect the genetic changes and analyzed the correlation with clinical outcomes. Results: Median age was 45 (range 32 – 62). Fifteen patients (88.2%) were relapsed mBC and most of the patients (14/17: 82.4%) were HR-positive and HER2-negative. Most of the patients had their ctDNA examined at baseline and at the time of maximal response and/or at progression. Fifteen patients (88.2%) received systemic therapy including hormone therapy, anti-HER2 therapy, and cytotoxic chemotherapy. Eight patients (47.1%) were on the first-line treatment for mBC, and 7 patients (41.2%) were on the second or later lines for mBC at the time of baseline sampling. The concentration of ctDNA and the sum of mutated allelic frequency was calculated for each sample. The ctDNA concentration ranged from 0.71 to 1386.00 ng/mL, and the median value was 5.37 ng/mL. We dichotomized these samples into two groups, with ctDNA concentration either higher or lower than the median value. Then we analyzed progression free survival (PFS) of each group. Patients with higher ctDNA concentration showed shorter PFS (7 mo. vs. not reached, p< 0.001). The sum of mutated allelic frequency ranged from 0.00% to 223.46% and the median value was 6.36%. Patients with higher mutated allelic frequency showed shorter PFS (6 mo. vs. 22 mo., p< 0.001). In addition, the PFS was significantly worse in patients who had mutated PIK3CA (5 mo vs. 22 mo, p< 0.001). The patients with mutated TP53 also showed shorter PFS (6 mo vs. 17 mo, p< 0.001) in univariate analysis. High estrogen receptor positivity in immunohistochemistry was correlated with lower mutated allelic frequency in ctDNA (p=0.003) but had no impact on the concentration of ctDNA (p=0.165). The concentration of ctDNA differed by metastatic sites. Patients with metastases to bones (p=0.007), liver (p< 0.001), soft tissue or lymph nodes (p=0.002) were more likely to have higher concentrations of ctDNA, while patients with brain metastases had significantly lower ctDNA concentration (p=0.006). When the sum of mutated allelic frequency of ctDNA and metastatic sites was analyzed, bone (p=0.001), liver (p< 0.001), and soft tissue or lymph node (p< 0.001) metastases had a positive correlation, while brain had negative correlation (p=0.017). Lung or pleural metastases had no significant correlation with ctDNA, neither concentration (p=0.271) nor mutated allelic frequency (p=0.965). Conclusion: Patients with mBC with higher concentrations of ctDNA or higher mutated allelic frequency of ctDNA at baseline showed significantly shorter PFS. PIK3CAmt and TP53mt detected by liquid biopsy could be used as a poor prognostic biomarkers for mBC patients. Citation Format: Hanbaek Yi, Tae-Yong Kim, Myung Geun Song, Hwang-Phill Kim, Tae-You Kim, Jinyong Kim, Dae-Won Lee, Kyung-Hun Lee, Seock-Ah Im. High circulating tumor DNA (ctDNA) concentration was associated with shorter progression free survival in patients with metastatic breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-13-11.

Abstract PO2-28-07: Artificial Intelligence-based Computer-aided Diagnosis for Mammography: Predicting Occult Invasive Cancer in Women with Biopsy-proven Ductal Carcinoma in Situ

Abstract Background: Ductal carcinoma in situ (DCIS) is a noninvasive breast cancer confined within the basement membrane. Due to the increase in breast cancer screening, DCIS is increasingly being diagnosed on biopsy. Active surveillance is a novel and evolving treatment strategy for DCIS to reduce overtreatment. Currently ongoing clinical trials of active surveillance include only mammographic findings in their eligibility criteria, however mammography has limited ability to detect occult invasive cancer. The objective of this study was to investigate whether an artificial intelligence-based computer-aided diagnosis (AI-CAD) application for mammography can improve the prediction of occult invasive cancer in women with percutaneous needle biopsy-proven DCIS. Methods: A retrospective search of our database identified consecutive women with percutaneous needle biopsy-proven DCIS who underwent surgery at Seoul National University Hospital (Seoul, Korea) between June 2019 and May 2021. Two board-certified breast radiologists reviewed preoperative mammographic findings of the primary tumor in consensus according to the Breast Imaging Reporting and Data System. Using a commercially available AI-CAD (Lunit INSIGHT for Mammography, Lunit Inc.), quantitative abnormality scores of 0 to 100% of the ipsilateral breast were obtained. Data were collected on age at diagnosis, symptoms, biopsy methods, DCIS grade on biopsy, and presence or absence of invasive cancer and axillary lymph node metastases on surgical pathology. Multivariable logistic regression models were used to evaluate factors associated with prediction of occult invasive cancer. Results: Of 692 biopsy-proven DCIS in 692 women (mean age, 53 years ± 11 [standard deviation]), 298 (43%) presented as calcifications only, 160 (23%) as mass or asymmetry, and 111 (16%) as masses with calcifications. The other 123 (18%) cancers were not demonstrable on mammography. Surgical pathology revealed occult invasive cancer in 278 (40%) women and 18 (3%) had axillary metastasis. Women with occult invasive cancer showed higher abnormality scores on AI-CAD than women with pure DCIS (mean, 70% vs. 51%; P < .001), and women with axillary metastasis had higher abnormality scores on AI-CAD than women without axillary metastasis (mean, 88% vs. 58%; P = .002). High ( >75%) abnormality score on AI-CAD (Odds ratio [OR], 1.8 [95% CI: 1.3, 2.6]; P < .001), age of 55 years or higher (OR, 1.6 [95% CI: 1.2, 2.3]; P =.005), present symptoms in the ipsilateral breast (OR, 2.7 [95% CI: 1.9, 4.0]; P < .001), biopsy performed with a 14-gauge automated gun (OR, 2.5 [95% CI: 1.7, 3.6]; P < .001), and high-grade DCIS at biopsy (OR, 2.5 [95% CI: 1.7, 3.5]; P < .001] were independent predictors of occult invasive cancer with a C-index of 0.75 (95% CI: 0.72, 0.78). Conclusion: The quantitative score of preoperative mammography obtained from a commercially available AI-CAD was able to predict occult invasive cancer in an easy and simple manner. AI-CAD applications for preoperative mammography may be useful in predicting occult invasive cancer in women with biopsy-proven DCIS, especially in those without preoperative breast MRI. Citation Format: Su Hyun Lee, Hajung Kim, Su Min Ha, Soo-Yeon Kim, Jung Min Chang, Nariya Cho, Woo Kyung Moon. Artificial Intelligence-based Computer-aided Diagnosis for Mammography: Predicting Occult Invasive Cancer in Women with Biopsy-proven Ductal Carcinoma in Situ [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-28-07.

Abstract PO4-12-05: Immediate breast reconstruction is associated with reduced incidence of ipsilateral lymphedema in breast cancer patients undergoing mastectomy

Abstract Purpose: The number of patients undergoing immediate breast reconstruction after mastectomy is increasing. A study of ipsilateral lymphedema after immediate breast reconstruction is also needed.This retrospective study aimed to identify the risk factors associated with lymphedema incidence after mastectomy in breast cancer patients, particularly focusing on the impact of the immediate breast reconstruction. Methods: A retrospective analysis was conducted on 6,105 patients who underwent mastectomy for breast cancer with or without immediate breast reconstruction from Jan 2012 to Dec 2022 at Seoul National University Hospital to identify the potential risk factors for developing ipsilateral lymphedema. Results: A total of 6,105 breast cancer patients with a mean age of 50.1 years were included in this study, with a median follow-up period of 52.0 months. In univariate analysis, the incidence of lymphedema was significantly lower in the immediate breast reconstruction group (4.47%) compared to the no reconstruction group (9.15%) (p < 0.001). Other significant risk factors included the number of dissected axillary lymph nodes, number of metastatic lymph nodes, body mass index (BMI) over 25 kg/m2, the use of neo-adjuvant chemotherapy or adjuvant radiation therapy, and older age at the time of operation. In multivariate analysis, the immediate breast reconstruction remained to be an independent predictor of developing lymphedema (OR: 0.71, 95% CI: 0.55-0.91, p = 0.008), along with the number of dissected lymph nodes (OR: 1.06, 95% CI: 1.05-1.08, p < 0.001), neoadjuvant chemotherapy (OR: 1.83, 95% CI: 1.44-2.33; p < 0.001), adjuvant radiation therapy (OR: 6.77, 95% CI: 5.16-8.96, p < 0.001), BMI >25 kg./m2 (OR: 1.58, 95% CI: 1.26–1.97, p < 0.001) and older age at surgery (OR: 1.01, 95% CI: 1.00-1.02, p = 0.007). Conclusion: Our data demonstrates significantly lower rates of ipsilateral lymphedema for the patients undergoing immediate reconstruction after mastectomy when compared to that of the mastectomy alone. While these observations require further validation, our study provides useful information for the surgical decision making in patients who are considering the option of immediate reconstruction after mastectomy. Citation Format: Jin Young Byeon, Ik Beom Shin, Hawjeong Lee, Eunhye Kang, Ji-Jung Jung, Changjin Lim, Wonshik Han, Hong-Kyu Kim, Han-Byoel Lee, Hyeong-Gon Moon. Immediate breast reconstruction is associated with reduced incidence of ipsilateral lymphedema in breast cancer patients undergoing mastectomy [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-12-05.

Immunogenicity, reactogenicity, and safety of two-dose adjuvanted herpes zoster subunit vaccine in patients with systemic lupus erythematosus in South Korea: a single-centre, randomised, double-blind, placebo-controlled trial

The adjuvanted herpes zoster subunit vaccine has shown good efficacy and safety in the general population. However, its effectiveness has not been comprehensively assessed in patients with systemic lupus erythematosus (SLE). This study aimed to evaluate the immunogenicity and safety of the adjuvanted herpes zoster subunit vaccine in patients with SLE. This single-centre, randomised, double-blind, placebo-controlled, trial was done at the rheumatology outpatient clinic at Seoul National University Hospital, South Korea. Patients (aged ≥19 years) with clinically stable SLE and previous exposure (≥4 weeks) to immunosuppressive drugs were randomly assigned (4:1) via a central interactive web response system to receive herpes zoster subunit vaccine or placebo (0·5 mL intramuscular injection) at weeks 0 and 8. Investigators and participants were masked to intervention and group assignment. Anti-glycoprotein E antibody titres and glycoprotein E-specific cell-mediated vaccine responses were evaluated at baseline and at week 8 after the first dose, and at week 4, week 26, and week 52 after the second dose using enzyme-linked immunosorbent assay and flow cytometry, respectively. Reactogenicity, SLE disease activity, including Systemic Lupus Erythematosus Disease Activity Index 2000 and British Isles Lupus Assessment Group-flare rate, were examined. The primary outcome was the proportion of patients with a positive humoral vaccine response 4 weeks after the second dose. The primary and safety analyses were done in a modified intention-to-treat population. This study is registered with ClinicalTrials.gov, NCT06001606. Between June 14, and July 19, 2023, 65 patients with SLE were enrolled, of whom 52 were randomly assigned to the herpes zoster subunit vaccine and 13 to placebo. 49 patients in the vaccine group and 11 patients in the placebo group were included in the modified intention-to-treat population. 56 (93%) of 60 patients were women and four (7%) were men. Mean age was 48·7 years (SD 11·4). The proportion of participants with a humoral vaccine response at 4 weeks after the second dose was significantly higher in the vaccine group (48 [98%] of 49 participants) than the placebo group (none [0%] of 11 patients; p<0·0001). More patients in the vaccine group than placebo group reported injection site reactions (42 patients vs two patients), fever (ten vs none), and fatigue (26 vs two). There were no differences in Systemic Lupus Erythematosus Disease Activity Index 2000 and British Isles Lupus Assessment Group-flare rates between the groups. There were no treatment-related deaths. The herpes zoster subunit vaccine induces humoral and cellular immunity against herpes zoster with a good safety profile in patients with SLE. A larger study is warranted to assess the efficacy of vaccines to prevent herpes zoster in patients with SLE. Ministry of Science and ICT, The Government of the Republic of Korea.

Anti-SARS-CoV-2 nucleocapsid antibody positivity 3 years after COVID-19.

The accurate identification of individuals without prior infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is pivotal for seroepidemiological research and vaccine trials. Because of widespread COVID-19 vaccination, the anti-nucleocapsid antibody continues to serve as a valuable marker for individuals without a history of COVID-19. This study aimed to comprehensively assess anti-nucleocapsid antibody positivity using diverse commercial and in-house immunoassays among individuals who contracted COVID-19 more than 3 years ago. We enrolled 44 participants with laboratory-confirmed COVID-19 between January and May 2020 from Seoul National University Hospital and its community treatment centers. The results showed anti-nucleocapsid antibody positivities ranged from 45.5% to 87.9% depending upon the immunoassay used. The study highlights the importance of considering the limited anti-nucleocapsid antibody positivity in participants with a distant COVID-19 history in seroepidemiological or vaccine research.

Vasopressor reduction effect of polymyxin B hemoperfusion in patients with peritonitis-induced septic shock: a propensity score-matched analysis.

This study aimed to evaluate the effect of polymyxin B hemoperfusion (PMX-HP) in patients with peritonitis-induced septic shock who still required high dose vasopressors after surgical source control. This retrospective study included adult patients admitted to the surgical intensive care unit (ICU) at Seoul National University Hospital between July 2014 and February 2021 who underwent major abdominal surgery to control the source of sepsis. Patients were divided into two groups based on whether PMX-HP was applied after surgery or not. The primary and secondary endpoints were the vasopressor reduction effect, and in-ICU mortality, respectively. Propensity score matching was performed to compare the vasopressor reduction effect. A total of 338 patients met the inclusion criteria, of which 23 patients underwent PMX-HP postoperatively, whereas 315 patients did not during the study period. Serum norepinephrine concentration decreased over time regardless of whether PMX-HP was applied. However, it decreased more rapidly in the PMX-HP(+) group than in the PMX-HP(-) group. There were no significant differences in demographics including age, sex, body mass index (BMI), and most underlying comorbidities between the two groups. Risk factors for in-ICU mortality were identified by comparing patient characteristics and perioperative factors between the two groups using multivariate analysis. For patients with peritonitis-induced septic shock, PMX-HP rapidly reduces the requirement of vasopressors immediately after surgery, but does not reduce in-ICU mortality. This effect could potentially accelerate recovery from shock, reduce sequelae from vasopressors, and ultimately improve quality of life after discharge.

Insights from Seoul National University Hospital's experience: a systematic review of pure laparoscopic donor hepatectomy progression.

Following its initial execution in November 2015, pure laparoscopic donor hepatectomy (PLDH) has gained acceptance as a conventional practice at Seoul National University Hospital (SNUH). It is noteworthy that a significant proportion of cases entail full right hepatectomies, which are acknowledged to be technically demanding. As expertise and knowledge have been accrued, the pure laparoscopic technique has been extended to encompass liver recipients as a viable option in SNUH. The aim of this review is to present the developmental progression of PLDH, with a focus on pure laparoscopic donor right hepatectomy (PLDRH), at SNUH. This includes the standardization process, which can be achieved by sharing the hospital's accumulated experience and previous reports. Various types of graft, including full right, left, left lateral section, and monosegment, were procured by pure laparoscopic technique. The criteria for selection were expanded to include donors with variations in the anatomy of the portal vein and bile duct. Additionally, the procedure of PLDRH was determined to be safe and viable for donors with high body mass index and larger graft weight. In conclusion, this review demonstrates the alterations implemented throughout our evolution from restricted to inclusive criteria for donor selection, leading to a complete shift from open surgery to pure laparoscopic procedures in donor hepatectomy and eventually pure laparoscopic living donor liver transplantation (LDLT) in recipient.

Blood glucose level affects iodine-123 labeled MIBG uptake in the lung

The aim of this study was to evaluate the correlation of blood glucose and the metaiodobenzylguanidine (MIBG) uptake in lung and compare the difference between the lung uptake of MIBG in diabetic and non-diabetic patients. Patients who underwent iodine-123 MIBG whole-body scan (WBS) in the Department of Nuclear Medicine Seoul National University Hospital between January 2014 and July 2022 were recruited and analyzed. Semi-quantitative analysis of the mean value of lung-to-mediastinum ratio (LMR) was performed. Correlation was analyzed with Pearson correlation test and mean difference was analyzed with independent t-test. There were 36 patients in diabetic group and 57 patients in non-diabetic group with mean age of 56 &amp;plusmn; 14.1 and 52 &amp;plusmn; 14.6 years, respectively. The mean 24-h LMRs in diabetic and non-diabetic groups were 1.38 &amp;plusmn; 0.20 and 1.17 &amp;plusmn; 0.14, respectively. Fasting glucose showed a mean value of 136 &amp;plusmn; 37.7 and 96 &amp;plusmn; 8.2 mg/dL, respectively. There was a significant positive correlation in diabetic (r = 0.397; P = 0.016) and non-diabetic groups (r = 0.579; P &lt;0.001) with significant mean difference (0.21; P &lt;0.001). In conclusion, lung uptake of MIBG is positively correlated with blood sugar level, with diabetic patients displaying higher lung uptake of MIBG compared with non-diabetic patients. In addition, higher lung uptake of MIBG is evident in patients with higher fasting glucose level and even in non-diabetic patients. Thus, in the situations where MIBG therapy is required, the radiation dose to the lungs must be carefully adjusted for patients with high blood sugar level.

Abstract 2266: Detection of androgen receptor splice variants from clinical sequencing

Abstract Background: Androgen receptor splice variant-7 (AR-v7) has been widely studied as a biomarker of resistance to AR-targeted therapy in castration-resistant prostate cancer (CRPC). Various methods have been used to detect AR-v7 in CRPC specimens, including next generation sequencing (NGS) technology. However, NGS technologies applied in clinical sequencing have focused on using blood or fresh-frozen CRPC tissue specimens. There is not yet an AR-v7 detection system tailored to formalin-fixed paraffin-embedded (FFPE) tissue specimens commonly used for clinical sequencing in hospitals. Methods: In this respect, we propose a novel approach to identify AR-v7 in targeted RNA sequencing (RNA-seq) data derived from FFPE specimens. This approach can identify, in addition to AR-v7, all constitutively active AR splice variants (AR-Vs) that are co-expressed with AR-v7. In short, our two-step approach first gathers soft-clipped or divided reads that are adjacent to the splicing sites of AR-Vs and then yields the number of splitting reads that support the existence of AR-Vs. Next, the algorithm selects the paired-end reads whose one side and the other side are mapped to the preceding and following exons, respectively. The final number of spanning reads are calculated following to the removal of low-quality reads. Results: We validated the proposed approach using two large-scale, independent RNA-seq datasets of prostate cancer (PC) samples: 111 samples from Seoul National University Hospital (SNUH) and 558 samples from The Cancer Genome Atlas (TCGA) dataset. The majority of both datasets were localized PC tumors, especially in the SNUH dataset, where localized PC accounted for 91% of the total. Overall, our approach successfully identified samples with putative AR-Vs, including AR-v7, AR-v3, and AR-v9. Statistical analyses of 111 SNUH PC patients suggested potential detection threshold in clinical sequencing settings (at least 200 split reads). In the SNUH dataset, the AR-v7 positive group, which included 5 patients (5%) with values above the threshold, shared the following characteristics: higher AR-v7/full length AR expression levels, AR amplification and co-expression with AR-v3/AR-v9. AR-v7 positivity was experimentally validated by Sanger sequencing. The similar pattern was also found in the analysis of TCGA dataset. Conclusions: These results demonstrate that the detection system can successfully identify AR-v7 positivity not only for metastatic PC but also for patients with localized PC through clinical sequencing. We expect that the further in-depth analyses including larger samples and clinical outcomes can discover clinical applicability of AR-v7. Citation Format: Suhyun Hwangbo, Sungyoung Lee, Sheehyun Kim, Hongseok Yun. Detection of androgen receptor splice variants from clinical sequencing [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2266.

Abstract 1065: Two-step method for early detection of ovarian cancer with high specificity via platelet RNA

Abstract Owing to lack of disease-specific symptoms and screening methods, most of patients with ovarian cancer are diagnosed at an advanced stage. Recent technology based on platelet RNA aids in detection of tumors at the early stages. Also, for population screening of low-prevalence diseases like cancer, accurate detection with high specificity is essential to improve diagnostic methods. Thus, we proposed platelet RNA-based early ovarian cancer detection with great specificity. It is a two-step method for detecting ovarian tumors with more than 99% specificity using exon-exon junction features and sampling invariant normalization and finding their malignancy with more than 99% negative predictive value using exon-exon junction and hematology parameters. First, we downloaded public platelet transcriptome data of gynecological cancer including ovarian cancer (n=151), benign tumor (n=30), and healthy counterparts (n=218) from GEO (GSE158508, 89843, and 183635). Second, we prospectively enrolled patients with gynecological cancer (n=31), benign tumors (n=20), and healthy women (n=18) at Seoul National University Hospital (SNUH) and Boaz Medical Center and obtained platelet transcriptome data (FMH data). Feature selection and model development were conducted using public training set (n=243), public validation set (n=156), and FMH training/validation set (n=47). The batch-invariant normalization was performed, and 198 splice junctions were selected as features from training/validation set for the bootstrap aggregation of the SVM model diagnosing the existence of an ovarian tumor. The model performance was assessed from a separate test set only composed of FMH data (n=22). Our model that demonstrated 96.8% sensitivity, 100.0% specificity, with a predetermined cut-off value. Next, FMH training/validation set was used for model development of following malignancy test. 10 splice junctions and 19 hematology parameters were selected and SVM models were separately developed for splice junctions and hematology parameters using 5-fold cross validation. The predictions were combined using a logical OR operation to obtain the final prediction result. The result showed its diagnostic performance with 100% sensitivity or NPV, and 50.0% specificity in the test data set with a predetermined cut-off value. We proposed a two-step method to operationally improve the existing protocol for ovarian cancer screening. Our model initially excludes most healthy individuals who do not have ovarian tumors and excludes patients with benign ovarian tumors who do not necessitate medical testing. To conclude, our model allows physicians to identify a subset of ovarian tumor patients with a higher risk of malignancy even at early stages; it exhibits potential in enhancing early diagnosis of ovarian cancer, leading to increase of treatment effectiveness and ultimately augmenting the survival of patients with ovarian cancer. Citation Format: Eunyong Ahn, Se Ik Kim, Sungmin Park, Sarah Kim, Yeochan Kim, Eunchong Huang, Suyeon Lee, Dong Won Hwang, Heeyeon Kim, HyunA Jo, Untack Cho, Juwon Lee, TaeJin Ahn, Yong-Sang Song. Two-step method for early detection of ovarian cancer with high specificity via platelet RNA [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1065.

Abstract 6150: MMP14 and MKLN1 as colorectal cancer susceptibility genes and a drug repurposing candidate from genome-wide association study in South Korea

Abstract Background: One of the major topics about colorectal cancer (CRC) is to find susceptible genes. Furthermore, functional interpretation of post-GWAS analysis gains attention and various approaches to find drug-repurposing candidates are used in cancer research. Our study aims to identify susceptible genes for CRC and provide drug-repurposing candidates. Methods: CRC patients in Seoul National University Hospital with prospective follow-up were recruited. From blood-derived DNA, genome-wide SNPs were genotyped using the Korea Biobank Array and 409,063 SNPs were extracted. SNP-based logistic regression model was fit for the event of CRC estimating beta values. Furthermore, post-GWAS analysis was conducted using regulatory function, multiple annotation and gene expression database. Drug-repurposing candidate was identified through the pre-trained deep neural network with susceptible genes. Results: We used 500 participants of CRC cases and 1,500 participants of healthy controls. For GWAS, statistically significant associations were mapped to MKLN1, MMP14, PTPN14 and MKL2 genes. For post-GWAS analysis, strong associations were found for MKLN1 (rs75170436, 7q32.3, Beta=-0.90, P-value=5.90×10-13) and MMP14 (rs3751489, 14q11.2, Beta=-1.91, P-value=2.31×10-12). From the drug-repurposing analysis, PPARδ/β agonist (GW0742; Binding score=3.79(MKLN1), 12.06(MMP14)) was identified for both genes with the highest score. Conclusions: We revealed MKLN1 and MMP14 genes as susceptible genes associated with CRC development. Additionally, we identified PPARδ/β agonist (GW0742) as a drug-repurposing candidate for the treatment of CRC. These findings can promote the understanding of CRC development and provide a novel therapeutic candidate for CRC patients in the future. Citation Format: Dabin Yun, Jung-Ho Yang, Sun-Seong Kweon, Jin-ah Sim, Minjung Kim, Ji Won Park, Seung Yong Jeong, Aesun Shin, Nan Song. MMP14 and MKLN1 as colorectal cancer susceptibility genes and a drug repurposing candidate from genome-wide association study in South Korea [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6150.

Abstract 4664: Therapeutic targeting of TP53-mutated acute myeloid leukemia by inhibiting cell cycle checkpoint

Abstract Acute myeloid leukemia (AML) is a hematological malignancy characterized by various somatic mutations leading to abnormal proliferation and differentiation of hematopoietic cells. Mutations on the TP53 gene occur in 5% to 10% of patients with de novo AML, with higher frequency in patients with relapsed and refractory (R/R) AML. Patients with TP53-mutated AML typically exhibit a poor response to conventional induction therapy and have a short overall survival (OS) rate, with a median duration of 5-9 months. Although various target agents have been developed for the treatment of AML, treatment options for TP53-mutated AML remain limited. Here, we have discovered a novel drug combination that can enhance the efficacy of the conventional therapeutic regimen for TP53-mutated AML patients. For in vitro analysis, we used the human AML cell line Kasumi-1(AML-M2), which harbors a homozygous TP53 R248Q mutation. We treated kasumi-1 cells with a combination of cytarabine and Idarubicin to produce drug tolerant persisters (DTPs) which is a minor population that survived the drug treatment. The Kasumi-1 DTPs displayed temporal G2/M phase cell cycle arrest and significant resistance to further repeated drug treatment. To discover drug candidates targeting TP53-mutated DTPs, we first examined the differentially expressed genes (DEGs) of TP53-mutated AML patients using patients’ RNA expression data deposited in the cancer genome atlas (TCGA) database. Using selected DEGs, drug candidates potentially affecting TP53-mutated AML cells were extracted from the connectivity map (CMap build 02) database. In addition, through a literature search, drugs with the ability to reactivate mutant p53, drugs that directly target mutant p53, synthetic lethal partners with mutant p53, and drugs that target leukemia stem cells were selected as candidate groups. As a result, we selected 46 drug candidates that would be effective for TP53-mutated AML through in silico analysis and therapy strategies targeting p53. Using in vitro cytotoxicity assay, we screened 46 candidate compounds at multiple doses and confirmed several drugs that effectively eliminate DTPs. The drug screening showed that cell cycle checkpoint inhibitors not only resulted in a significant reduction of G2/M phase arrested cells but also induction of apoptotic cells at the subG1 phase. Furthermore, the zero interaction potency (ZIP) model of SynergyFinder (https://synergyfinder.fimm.fi) analysis showed that cell cycle checkpoint inhibitors synergistically enhanced the cytotoxic effect of cytarabine on Kasumi-1 DTPs. Collectively, this study suggests that novel combination treatment of cell cycle checkpoint inhibitors with conventional drugs selectively inhibits TP53-mutated AML DTPs. Citation Format: Daehyeon Gwak, Dongchan Kim, Heejun Jang, Jun Liu, Suji Min, Ja Min Byun, Youngil Koh, Junshik Hong, Sung-soo Yoon, Dong-Yeop Shin, Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea, Republic of. Therapeutic targeting of TP53-mutated acute myeloid leukemia by inhibiting cell cycle checkpoint [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4664.