Primary Tumor Status Research Articles

Role of androgen receptor expression in the metastatic potential of colorectal carcinoma

Background The prevalence of colorectal cancer (CRC) is widespread and associated with significant morbidity and deaths. In CRC, hormone receptors, such as androgen receptors (AR), are pathologically modified. Additional research is required to understand better its function and predictive and therapeutic value in CRC metastatic potential. Objective To assess the AR status in CRC primary tumors and metastatic lymph nodes. Methods Tissue microarray and immunohistochemical techniques were applied to 75 CRC cases with lymph node (LN) metastases. We correlate the results with all relevant clinicopathological indicators of prognostic relevance. Results and conclusion Out of the 75 cases that were analyzed, 16% of CRC primaries and 12% of LN metastases had nuclear AR that was focally positive. AR expression was significantly correlated with advanced age, conventional non-mucinous histology, lower grade, and arousal on top of adenoma. A deeper invasion was likewise linked to AR expression; however, this association was not statistically significant. AR expression has a positive prognostic influence since the median overall and disease-free survival of cases with positive AR expression in either primary carcinomas or LN metastases were significantly higher than that of cases with negative expression in both primary and LN metastases. We assume that AR expression in CRC has a positive prognostic influence.

Validity test of small cell lung cancer (SCLC) graded prognostic assessment and proposal of a new index for patients with brain metastases from SCLC

Background and purposeWe performed a validity test of a recently-reported, small cell lung cancer (SCLC) graded prognostic assessment (GPA) system for SCLC patients with brain metastases (BMs). Thereafter, we created a new prognostic index, the SCLC Grade, for such patients. Materials and methodsWe studied 508 SCLC patients selected from among nearly 7000 consecutive patients undergoing gamma knife SRS for BMs since 1998. ResultsIn the SCLC GPA, there were no median survival time (MST) differences among pairs of the neighboring subgroups. Therefore, the 508 patients were randomly divided into the two series, i.e., a test (340 patients) and a validity (168) series. In the test series, five factors were identified by univariable analyses as favoring longer survival (rounded lower 95 % CI of the HR was at least 1.3): Sex, Karnofsky Performance Status, tumor numbers, primary tumor status and extracerebral metastases. This new index is the sum of scores (0 and 1) of these five factors: SCLC-Grade 4–6 (score of 4, 5 or 6), 2–3 (2 or 3), and 0–1 (0 or 1). This new system showed highly statistically significant MST differences among subclasses. Next, this SCLC-Grade was applied to the verification series. Consistent results were obtained, i.e., there were highly statistically significant MST differences among subclasses. ConclusionsOur validity test results for the SCLC GPA demonstrated this system to not precisely reflect the outcomes of SCLC patients with BMs. Our results suggest the herein-proposed SCLC-Grade to have superior prognostic value.

Biomarker conversion from primary breast cancer to synchronous axillary lymph node metastasis and neoadjuvant therapy response: a single-center analysis

PurposeThe biomarker characteristics of breast cancer plays an important role in predicting treatment sensitivity. The aim of the present study was to compare immunohistochemical profiles (ER, PR, HER2, and Ki67) between the primary tumor and synchronous axillary lymph node metastasis and investigate the subsequent effects on neoadjuvant therapy response.MethodsA total of 358 patients with pathologically confirmed synchronous axillary lymph node metastasis at first diagnosis and treated by neoadjuvant therapy at Peking University First Hospital from January 1, 2013 to December 31, 2022 were included in this retrospective study. Clinicopathologic data, especially receptor status in primary and metastatic foci, was collected for each case.ResultsChange of ER, PR, HER2, and Ki67 expression was observed in 5.9%, 8.7%, 12.6%, and 17.3% of patients, respectively. HR discordance was observed more frequently when the ER status (p = 0.023) or PR status (p = 0.010) of primary tumor was negative, while HER2 discordance seemed to be more frequent when the HER2 status of primary tumor was HER2-0 or HER2-low (p < 0.001). Patients with loss of HR-positivity (positive to negative) responded to neoadjuvant chemotherapy better compared to those with stable positive HR expression (50% vs. 11.1%, p = 0.0017). A significantly decrease in pCR rate was observed in patients with unstable HER2 status, but not in the HER2-0/HER2-low subgroup.ConclusionReceptor discordance between primary tumor and synchronous axillary LNM appears to already exist before any anti-tumor therapy. This instability has limited clinical impact on the choice of neoadjuvant therapy at current stage, but further investigation is warranted with the incremental application of endocrine drugs and ADCs in neoadjuvant therapy.

Abstract PO1-13-09: Programmed cell death ligand 1 (PD-L1) is constitutively expressed on tumorspheres cultured from circulating cancer stem cells in breast cancer patients

Abstract Background Circulating cancer cells, and in particular their very rare subpopulation, circulating cancer stem cells (cCSCs), are responsible for recurrence and metastasis. The exact role of cCSCs in escape of cancer from immunosurveillance is still unknown, but recent studies revealed that enhanced PDL-1 expression in cancer stem cells is a novel mechanism to promoting cancer cell immune evasion and could crucially contribute to the maintenance of CSC self-renewal. Understanding the mechanisms behind this PDL-1 overexpression in cancer stem cells is critical for developing more effective anti-PD-1/PD-L1 therapy. Therefore the aim of the study was to determine the number of tumorspheres and expression of PD-L1 on tumorspheres cultured from cCSC in breast cancer patients. Methods: 110 patients with breast cancer in different stages of disease were included in this study. The determination of circulating cancer stem cells was performed using the sphere-forming assay. Additionally anti-PDL-1 antibody staining was applied to examine PDL-1 expression on breast tumorspheres. Results: We have developed an innovative in vitro platform for detection of cCSCs from peripheral blood of cancer patients. The number of tumorspheres increased significantly with tumor progression and aggressiveness of primary tumor. Patients with metastatic disease had statistically more tumorspheres as compared to patients without metastasis (30 vs 10/100µl blood, p&amp;lt; 0.05). Patients with multiple metastasis had more tumorspheres compared to patients with single metastases (60 vs 30/100µl blood, p&amp;lt; 0.05). The number of tumorspheres was positively correlated with Ki-67, Her2 status and grade score in primary breast tumors. We observed high PDL-1 expression and their considerable heterogeneity in enriched tumorspheres. Conclusion: The number of tumorspheres cultured from peripheral blood directly reflects aggressiveness and proliferation capacity of primary tumor. The presence of tumorspheres with expression of PDL-1 might suggest their immunomodulating potential. Better understanding of the interaction between cCSCs and tumor immunology may help to identify strategies to eradicate the minor subpopulation that escapes conventional therapy attack, thus providing a solution to the problem of drug resistance and metastasis. Citation Format: Monika PIZON, Dorothea Schott, Ulrich Pachmann, Katharina Pachmann. Programmed cell death ligand 1 (PD-L1) is constitutively expressed on tumorspheres cultured from circulating cancer stem cells in breast cancer patients [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 PO1-13-09.

Abstract 3758: Evaluation of breast cancer-derived extracellular vesicles as diagnostic indicator for HER2 status

Abstract HER2-low is a new distinct type of breast cancer that is characterized by low levels of the HER2 protein. As treatment paradigms for HER2-low breast cancer are rapidly evolving with the approval of antibody-drug conjugates, identification of HER2-low breast cancer with more sensitive and reproducible HER2 assays is needed. We aimed to investigate the utility of liquid biopsy in isolating tumor-derived extracellular vesicles (TDEs) for diagnosis of HER2 status. We adopted an affinity-based approach to isolate TDEs and performed CNV analysis of the ERBB2/neu genes using the tumor DNA present in TDEs (etDNA). HER2 status of etDNA had been determined by droplet digital PCR using HER2/EIF2C ratio, a highly accurate method to quantify DNA copy number. In our study, we utilized a variety of breast cancer cell lines categorized as HER2-low (MDA-MB-231, MCF7, ZR-75-1) and HER2-high (MDA-MB-453, BT-474, SK-BR-3) to confirm HER2 expression in extracellular vesicles (EVs) by flow cytometry. This analysis successfully demonstrated that EVs effectively reflect the HER2 status of the tumor cells, evidenced by a strong Pearson correlation coefficient (r=0.987, p&amp;lt;0.001). Further clinical validation was conducted with plasma samples from 22 breast cancer patients. In the clinical study, we observed a significant correlation between the CNV of tumor DNA present in TDEs and the HER2 status of primary tumors (p&amp;lt;0.01). Additionally, the Receiver Operating Characteristic (ROC) analysis yielded an impressive area under the curve (AUC) value of 0.838 (p&amp;lt;0.01), demonstrating a high level of accuracy in differentiating between high and low HER2 groups, with a sensitivity of 55.6% and a specificity of 100%. In summary, we show potential diagnostic tools for real-time, less invasive determination of HER2 status in primary tumors, providing continuous monitoring methods for HER2 status. Although further validation in larger cohorts and prospective studies is needed, our study indicates that TDE analysis could contribute to the assays for identification of the HER2 status in breast cancer patients. Citation Format: Sol Moon, Min Woo Kim, Young Kim, Suji Lee, Hyojung Lee, Joon Ye Kim, Seung Il Kim, Jee Ye Kim. Evaluation of breast cancer-derived extracellular vesicles as diagnostic indicator for HER2 status [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 3758.

Prognostic factors and real-life applicability of prognostic models for patients with bone metastases of carcinoma.

This study aimed to investigate the factors affecting the survival of patients with bone carcinoma metastases and assess the clinical applicability of existing prognostic models. We retrospectively evaluated 247 patients who presented to our hospital between 2011 and 2021 diagnosed with bone carcinoma metastasis. Demographic data, general health status, primary diagnoses, laboratory and radiological findings, pathological fracture status, treatment methods, and survival times of the patients were recorded, and the effects of these variables on survival time were evaluated. Previously developed Katagiri, Janssen, 2013-Spring, PathFX, and SORG prognostic models were applied, and the predictive performances of these models were evaluated by comparing the predicted survival time with the actual survival time of our patients. After the multivariate analysis, the following factors were shown to be significantly associated with the survival time of patients: blood hemoglobin and leukocyte levels, lactate dehydrogenase concentration, prognostic nutritional index, body mass index, performance status, medium and fast-growing groups of primary tumors, presence of extraspinal and visceral or brain metastases, and pathological fractures. According to receiver operating characteristics and Brier scores, SORG had the overall highest performance scores, while the Janssen nomogram had the lowest. Our report showed that all prognostic models were clinically applicable, but their performances varied. Among them, the SORG predictive model had the best performance scores overall and is the model the authors suggested for survival prediction among patients with carcinoma bone metastases. Level IV, Prognostic Study.

Evaluation of HER2/neu Expression in Metastatic Axillary Lymph Node Tissue of Breast Cancer Patients Using [99mTc]Tc-(HE)3-G3.

Anatomic visualization and molecular typing of metastatic regional lymph nodes in breast cancer patients are a serious clinical challenge in modern oncology. According to the results of previous studies, [99mTc]Tc-(HE)3-G3 has proven to be a promising diagnostic agent in differentiating the HER2/neu receptor status in primary breast tumors (p < 0.05, Mann-Whitney test). In this regard, the purpose of this study is to explore the possibilities of using [99mTc]Tc-(HE)3-G3 to determine the HER2/neu receptor status in the metastatic axillary lymph nodes (mALNs) of breast cancer patients. The study was conducted using clinical material from 20 breast cancer patients (T2-4N1-3M0-1) before systemic therapy (10 patients with positive and 10 patients with negative HER2/neu expression in mALNs) who underwent SPECT/CT scan 4 h after the administration of [99mTc]Tc-(HE)3-G3. Morphological and immunohistochemical studies of mALNs with assessment of the HER2/neu status were performed on all patients. We found that mALN-to-background and mALN-to-latissimus dorsi muscle ratios for [99mTc]Tc-(HE)3-G3 uptake 4 h after its administration may be used for typing of the HER2/neu status in mALNs of breast cancer patients (p < 0.05, Mann-Whitney test). In that case, sensitivity and specificity for the mALN-to-background ratio were identical at 80%, with the threshold value being > 12.25.

Overexpression of KLHL22 correlates with poor prognosis in patients with triple-negative breast cancer.

Kelch-like family member 22 (KLHL22) is a protein-coding gene that is responsible for several Mendelian diseases and has been reported to promote tumorigenesis and aging. The purpose of this study was to investigate its expression in triple-negative breast cancer (TNBC) and its prognostic significance. Immunohistochemistry (IHC) was performed to examine the expression levels of KLHL22 in 146 patients with TNBC. The Chi-squared test was used to analyze the correlations between KLHL22 expression level and clinicopathological features, and the Kaplan-Meier survival analysis and Cox multivariate regression model were used to analyze the prognostic significance of KLHL22 in patients with TNBC. The results of immunohistochemical analysis showed that the high expression rate of KLHL22 protein in TNBC was 56.85% (83/146). Further analysis revealed a significantly positive correlation (P<0.05) between KLHL22 expression and primary tumor and regional lymph node status, clinical stage, and relapse. Kaplan-Meier survival analysis revealed that patients with low KLHL22 expression had a longer mean survival time than those with high KLHL22 expression (147.93 vs. 90.1 months; P<0.05). In the multivariate analysis, KLHL22 level, P53 expression, and clinical stage were found to be independent prognostic factors for overall survival (P<0.05), while clinical stage and KLHL22 level were independent prognostic factors for progression-free survival (P<0.05). The present study concludes that KLHL22 may serve as a biomarker for poor prognosis in patients with TNBC.

Optimizing Treatment Strategy for Oligometastases/Oligo-Recurrence of Colorectal Cancer.

Colorectal cancer (CRC) is the third most common cancer, and nearly half of CRC patients experience metastases. Oligometastatic CRC represents a distinct clinical state characterized by limited metastatic involvement, demonstrating a less aggressive nature and potentially improved survival with multidisciplinary treatment. However, the varied clinical scenarios giving rise to oligometastases necessitate a precise definition, considering primary tumor status and oncological factors, to optimize treatment strategies. This review delineates the concepts of oligometastatic CRC, encompassing oligo-recurrence, where the primary tumor is under control, resulting in a more favorable prognosis. A comprehensive examination of multidisciplinary treatment with local treatments and systemic therapy is provided. The overarching objective in managing oligometastatic CRC is the complete eradication of metastases, offering prospects of a cure. Essential to this management approach are local treatments, with surgical resection serving as the standard of care. Percutaneous ablation and stereotactic body radiotherapy present less invasive alternatives for lesions unsuitable for surgery, demonstrating efficacy in select cases. Perioperative systemic therapy, aiming to control micrometastatic disease and enhance local treatment effectiveness, has shown improvements in progression-free survival through clinical trials. However, the extension of overall survival remains variable. The review emphasizes the need for further prospective trials to establish a cohesive definition and an optimized treatment strategy for oligometastatic CRC.

A Correlative Study on EGFR Gene Mutation Status of Primary Lung Tumor and Brain Metastases in NSCLC

Objective: This study aims to explore the predictive role of EGFR gene mutation in the primary lung tumor on brain metastases in Non-Small Cell Lung Cancer (NSCLC). Methods: Morphological differences between EGFR gene 19 exon deletion mutant HCC827 and wild-type EGFR gene A549 human lung adenocarcinoma cells were observed under a microscope. The MTT method was employed to detect the proliferation differences between HCC827 and A549 cells. The Transwell in vitro cell invasion experiment was used to compare the invasion capabilities of the two cell lines. Furthermore, the Χ2 test was applied to analyze the relationship between the EGFR mutation in the primary lung tumor and the occurrence of brain metastases in 253 NSCLC patients. Results: A549 cells were smaller in size, resembling paving stones, whereas HCC827 cells were larger and polygonal. MTT analysis revealed that wild-type EGFR A549 human lung adenocarcinoma cells proliferated faster than EGFR mutant HCC827 cells, with a significant difference (P&lt;0.05). The Transwell in vitro cell invasion experiment indicated that HCC827 cells were significantly stronger than A549 cells (P&lt;0.05). The incidence of brain metastases in 253 NSCLC patients was 12.3% (31/253), among which eight cases had EGFR gene mutations in primary lung tumor, with a mutation rate of only 25.81% (8/31). No significant correlation was found between the occurrence of brain metastases and the mutation in primary lung tumor. Conclusion: EGFR gene mutation in NSCLC cells can significantly enhance their invasive activity. However, the correlation between EGFR gene mutation in primary lung tumor and the occurrence of brain metastases warrants further study.

HER2-low heterogeneity between primary and paired recurrent/metastatic breast cancer: Implications in treatment and prognosis.

With the largest sample size to date, the authors' objective was to investigate the incidence of primary-to-metastatic human epidermal growth factor 2 (HER2) conversion and the predictors for such conversion. Moreover, no previous studies have evaluated the prognosis of patients who have negative HER2 expression (HER2-0) versus low HER2 expression (HER2-low) when HER2 status was assessed based on all recurrent/metastatic lesions. The authors included 1299 patients who had available HER2 status of primary breast tumors and paired recurrent/metastatic lesions at Fudan University Shanghai Cancer Center and West China Hospital. In total, 370 patients (28.5%) experienced primary-to-metastatic HER2 conversion. Intrapatient intermetastasis spatial heterogeneity and temporal heterogeneity of HER2 were detected. When assessing HER2 based on recurrent/metastatic tumors, patients who had HER2-0 tumors had significantly shorter overall survival than those who had HER2-low tumors in the overall population and in the estrogen receptor (ER)-negative subgroup. However, when assessing HER2 based on primary tumors, there was no difference in overall survival between patients who had HER2-0 versus HER2-low tumors. Moreover, patients who had tumors that converted from HER2-0 to HER2-low had longer overall survival than those who had consistent HER2-0 status in the ER-negative subgroup. By combining four predictors (ER status, Ki67 index, biopsy site, and disease-free interval), the authors established the first prediction tool to estimate the probability of HER2-0 tumors converting to HER2-low/positive tumors. Intrapatient primary-to-metastatic and intermetastatic HER2 heterogeneity were observed in this large-scale cohort study. When evaluating HER2 based on recurrent/metastatic tumors, an overall survival difference was observed between patients who had HER2-0 versus HER2-low, recurrent/metastatic breast tumors. The developed prediction tool might help clinicians screen out patients with primary HER2-0 tumors that have a high probability of HER2 status conversion and recommend them for re-biopsy, thus helping to screen out candidate patients for trastuzumab deruxtecan treatment.

Correlation of the Geriatric Assessment with Overall Survival in Older Patients with Cancer

AimsGlobal guidelines recommend that all older patients with cancer receiving chemotherapy should undergo a geriatric assessment. However, utilisation of the geriatric assessment is often constrained by its time-intensive nature, which limits its adoption in settings with limited resources and high demand. There is a lack of evidence correlating the results of the geriatric assessment with survival from the Indian subcontinent. Therefore, the aims of the present study were to assess the impact of the geriatric assessment on survival in older Indian patients with cancer and to identify the factors associated with survival in these older patients. Materials and methodsThis was an observational study, conducted in the geriatric oncology clinic of the Tata Memorial Hospital (Mumbai, India). Patients aged 60 years and older with cancer who underwent a geriatric assessment were enrolled. We assessed the non-oncological geriatric domains of function and falls, nutrition, comorbidities, cognition, psychology, social support and medications. Patients exhibiting impairment in two or more domains were classified as frail. ResultsBetween June 2018 and January 2022, we enrolled 897 patients. The median age was 69 (interquartile range 65–73) years. The common malignancies were lung (40.5%), oesophagus (31.9%) and genitourinary (12.1%); 54.6% had metastatic disease. Based on the results of the geriatric assessment, 767 (85.4%) patients were frail. The estimated median overall survival in fit patients was 24.3 (95% confidence interval 18.2–not reached) months, compared with 11.2 (10.1–12.8) months in frail patients (hazard ratio 0.54; 95% confidence interval 0.41–0.72, P < 0.001). This difference in overall survival remained significant after adjusting for age, sex, primary tumour and metastatic status (hazard ratio 0.56; 95% confidence interval 0.41–0.74, P < 0.001). In the patients with a performance status of 0 or 1 (n = 454), 365 (80.4%) were frail; the median overall survival in the performance status 0–1 group was 33.0 months (95% confidence interval 24.31–not reached) in the fit group versus 14.4 months (95% confidence interval 12.25–18.73) in the frail patients (hazard ratio 0.50; 95% confidence interval 0.34–0.74, P = 0.001). In the multivariate analysis, the geriatric assessment domains that were predictive of survival were function (hazard ratio 0.68; 95% confidence interval 0.52–0.88; P = 0.003), nutrition (hazard ratio 0.64; 95% confidence interval 0.48–0.85, P = 0.002) and cognition (hazard ratio 0.67; 95% confidence interval 0.49–0.91, P = 0.011). DiscussionThe geriatric assessment is a powerful prognostic tool for survival among older Indian patients with cancer. The geriatric assessment is prognostic even in the cohort of patients thought to be the fittest, i.e. performance status 0 and 1. Our study re-emphasises the critical importance of the geriatric assessment in all older patients planned for cancer-directed therapy.

The radiological unknown primary of the head and neck: Recommendations for imaging strategies based on a systematic review.

To develop recommendations for the radiological investigation of clinically occult primary cancer in the head and neck. In accordance with PRISMA guidelines, a search was performed on Medline, Embase and Cochrane library databases to investigate the efficacy of ultrasound guided Fine Needle Aspiration (US FNAC), contrast enhanced CT (CECT), magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose PET-CT (18F-FDG PET-CT) in the investigation of head and neck squamous cell carcinoma from an unknown primary (HNSCCUP) presenting with a metastatic cervical lymph node (s). The Quality Assessment of Diagnostic Accuracy Studies Version 2 tool and SIGN 50 guidelines were used to assess the risk of bias and quality of the included studies. Adult patients presenting with metastatic cervical lymph nodes from a HNSCCUP. Utility of different imaging modalities (PET-CT, MRI, CE CT and US FNAC in the management of HNSCCUP). Twenty-eight studies met inclusion criteria; these were meta-analyses, systematic reviews, prospective and retrospective studies. The optimal imaging strategy involves utilisation of various imaging modalities. US FNAC can provide the initial diagnosis and HPV status of the occult primary tumour. CECT and MRI detect up to 44% of occult tumours and guide management. FDG PET-CT is the most sensitive imaging modality for the detection of CUP and should be performed prior to panendoscopy.

Significance of fusion status, Oberlin risk factors, local and maintenance treatment in pediatric and adolescent patients with metastatic rhabdomyosarcoma: Data of the European Soft Tissue Sarcoma Registry SoTiSaR.

Outcome of primary metastatic rhabdomyosarcoma (RMS) is poor. Certain risk factors as fusion status, Oberlin score, and local treatment of primary tumor are known to influence prognosis. Patients with metastatic RMS were treated according to Cooperative Weichteilsarkom Studiengruppe (CWS) guidance with chemotherapy (CHT), radiotherapy (RT) excluding total lung irradiation (TLI), complete resection of the primary tumor, and metastasectomy if possible. Kaplan-Meier estimators and Cox proportional hazard models were used to examine event-free survival (EFS) and overall survival (OS) involving also landmark analyses. In the European Soft Tissue Sarcoma Registry SoTiSaR (2009-2018), 211 patients were analyzed. Many patients had fusion-positive alveolar RMS (n=83; 39%). Median age was 9.4years [0.1-19.7years]. Treatment primarily consisted of CHT with CEVAIE (carboplatin, epirubicine, vincristine, actinomycin-D, ifosfamide, etoposide: 86%, other regimens: 14%), RT (71%), resection of primary tumor (37%), metastasectomy (19%), and lymph node sampling/dissection (21%). Maintenance treatment (MT) (oral trofosfamide, idarubicin, etoposide) was added in 74% of patients. Oberlin factors, fusion status, and MT were predictive for EFS and OS. MT with O-TIE was not improving outcome when adjusting for the immortal time bias. Local treatment of the primary tumor and radical irradiation (except TLI) improved EFS, not OS, when adjusting for the Oberlin score. Patients with fusion-negative alveolar RMS (n=9) had an excellent outcome with a 5-year EFS and OS of 100%, compared to patients with embryonal RMS (49%/62%), PAX7- (22%/47%) and PAX3/FOXO1-positive ARMS (10/13%), respectively (p<.001). Prognosis of metastatic RMS primarily depends on fusion status and Oberlin score. Fusion status needs to be considered in future trials to optimize treatment outcome. The role of radical irradiation needs further investigation.

Long Term Clinical Outcomes of a Cohort of Lung-Only Oligometastatic HNSCC Patients Treated with SBRT

Oligometastatic disease in head and neck squamous cell carcinoma (HNSCC) is a rare setting. Local ablative therapies are the most adopted strategies although no evidence-based recommendations are currently published. The aim of our analysis was to update and report on long-term clinical outcomes of a cohort of HNSCC patients treated with stereotactic body radiotherapy (SBRT) for lung-only oligometastatic disease. Eligible patients had 1 to 5 lung metastases. The oligometastatic pattern was classified as "de novo" (suitable for SBRT only) or "oligoprogressive" (after first line of systemic therapy). We evaluated time to progression (TTP) as the time from the last day of SBRT to disease progression or death from any cause. Predictive factors of better clinical outcome and survival analysis were performed by Cox regression and Kaplan Meier methods, respectively. A cohort of 46 patients and 47 metastases were retrospectively evaluated. The median age was 67 years (range 37-86) and 87% of patients had a ECOG PS 0-1. HPV negative status (77%) and "de novo" oligometastatic pattern (78%) were reported by the majority of patients. After a median follow up of 28 months (range 2-88), median TTP and overall survival (OS) were 18 months (95% CI 4.8 - 31.2) and 62 months (95% CI 10,8 - 113.2), respectively. The median volume of planning target volume (PTV) was 20.4 cc (range 7.1-55.3). At univariate analysis, patients aged > 70 years reported a better TTP (p 0.013). No statistically significant correlation was observed in respect with gender (p 0.23), ECOG PS (p 0.34), oligometastatic pattern (p 0.13) and p16/HPV status (p 0.22). Out of 26 histologically proven metastases, we collected only 2 patients reporting concordance between p16/HPV positive status of primary tumor and lung metastases. Overall, 6 patients reported grade (G) 1-2 acute toxicity and no acute G3 adverse events were observed. Our findings suggested that SBRT may improve clinical outcome prolonging time to progression and to systemic treatments in a properly selected cohort of HNSCC patients with lung-only oligometastatic disease. Distant metastases from HPV-related primary HNSCC should be tested for p16/HPV status given the clinical implications of HPV positivity for diagnosis and treatment.

QUANTIFYING THE NEED FOR A BEST SUPPORTIVE CARE CLINIC

Abstract AIMS Patients newly diagnosed with high-grade primary brain tumour and poor performance status discussed in the Multidisciplinary team (MDT) may not be felt to benefit from active treatment and their uptake in clinic is poor. We aimed to explore the volume of patients not being treated in our region, their survival rates, and the reasons for the limited requests for clinical review. METHOD Data was obtained from medical records of identified patients from April 2021 to April 2022. This included demographics, presentation, diagnosis date, clinic visits, and date of death. RESULTS 78 patients were referred for suspected high-grade primary brain tumours and selected for best supportive care by the MDT. Only 73 (64% male) were diagnosed radiologically with a high-grade primary tumour and the rest were excluded. Median age was 79 years (range 74 – 84). The commonest presenting symptoms were confusion (53%), falls (29%), and dysphasia (25%). Median survival time after diagnostic scan was 67 days (range 34 – 107). Survival rates at 1, 3, 6, and 12 months were 82%, 33%, 8%, and 1%, respectively. 28 patients (38%) were seen in clinic. 13 had been provided with the option to attend by letter. The median duration from referral to clinic was 9 days (range 7 – 14). CONCLUSIONS Only a third of non-treatable patients with newly diagnosed high-grade primary brain tumours are being seen in the clinic. Communication between the MDT and the patient offering this service is poor. Longer term survivors suggest an incorrect diagnosis who may benefit from further review.

P13.06.A RADIOMIC FEATURES FOR RISK-STRATIFICATION IN PATIENTS WITH BRAIN METASTASES

Abstract BACKGROUND Recently, non-invasive characterization of brain tumors on MRI has emerged as a promising field of research. The identification of quantitative imaging biomarkers, also known as radiomics, may complement molecular characterization and thereby improve clinical management of neuro-oncologic patients. In this study we aimed to identify imaging predictors with improved performance over clinical parameters in order to stratify patients with brain metastases into high and low risk groups for overall survival (OS). MATERIAL AND METHODS 422 patients (allocated in a 3:1 ratio to a discovery [n=317] and test [n= 105] set) with first diagnosis of brain metastases from different primary tumors from two neuro-oncologic centers were included. In each patient, eight clinical features (age, gender, KPS, systemic disease status, presence of extracranial metastases, number of cerebral metastases, primary tumor and available individual prognostic molecular status eg HER2, BRAF,⋯) were gathered and a total of 321 radiomic MRI features (including shape, first-order and higher-order features) from cerebral MRI (contrast T1-weighted and apparent diffusion coefficient maps) were extracted. Radiomic and clinical features of patients in the discovery set were subjected to different machine learning models in order to classify patients into low- and high-risk groups for OS. By performing a comprehensive grid search the best machine learning model according to the macro-evaluated score and accuracy was identified and evaluated on the testing set. In addition, a subgroup analysis, based on the primary tumor entity was done and confusion matrices were calculated in order to evaluate final predictions. RESULTS With an extra trees classifier including all clinical and 30 radiomic features, we were able to stratify patients into a high- and low-risk group for OS (test set: macro-evaluated = 0.60, accuracy = 0.67). The best performing model was a gradient boosting model only including clinical features (test set: macro-evaluated = 0.62, accuracy = 0.72), while the radiomic features alone led to the poorest results (test set: macro-evaluated = 0.52, accuracy = 0.63). Interestingly, in the subgroup of melanoma patients, the predictive power of radiomic features outperformed the clinical and the combined (radiomics and clinical) features. With a prediction solely based on radiomic features, 80% and 67% of patients were correctly classified into the low- and the high-risk group for OS, respectively. CONCLUSION In conclusion, we found that in the entire study population of patients with brain metastases radiomic features did not allow for a better prediction of the clinical outcome compared to the clinical parameters alone. However, in the subgroup of melanoma patients the predictive power of radiomic features alone was superior compared to clinical features or all features combined.

Discordance in PD-L1 expression using 22C3 and SP142 assays between primary and metastatic triple-negative breast cancer.

SP142 and 22C3 assays are approved companion diagnostic assays for anti-PD-1/PD-L1 therapy selection in metastatic triple-negative breast cancer (TNBC). The discordance in PD-L1 status between primary and metastatic tumors in the same patient has been poorly characterized. Here, we examined the concordance of PD-L1 status between the two assays and between primary tumors and metastases for each assay. We retrospectively evaluated tumor samples from 160 patients with TNBC, including 45 patients with paired primary and metastatic tumors. PD-L1 status was assessed using SP142 and 22C3 assays, to determine the immune cell (IC) score, tumor cell (TC) score (SP142 and 22C3), and combined proportion score (CPS: 22C3). The concordance of PD-L1 positivity at diagnostic cutoffs for SP142 (IC ≥ 1) and 22C3 (CPS ≥ 10) was substantial (κ = 0.80) in primary tumors and moderate (κ = 0.60) in metastatic tumors. In comparison, between primary and metastatic tumors, the concordance with 22C3 was moderate (κ = 0.50), whereas that with SP142 was poor (κ = -0.03). Among patients who were PD-L1 negative for both assays in primary tumors, 7/30 (23.3%) were PD-L1 positive for both or either 22C3 or SP142 in the metastatic tumors. The inter-assay concordance of PD-L1 positivity at diagnostic cutoffs was substantial in primary tumors and moderate in metastatic tumors. Discordance between PD-L1 status in primary and metastatic tumors was frequently observed, especially with SP142. Some patients with a PD-L1-negative status in primary tumors may still be candidates for immunotherapy, depending on the PD-L1 status in their metastatic tumors.

31. MULTICENTER RANDOMIZED CLINICAL TRIAL OF CRT VS DCF AS INITIAL TREATMENT FOR SUBSEQUENT CONVERSION SURGERY FOR CLINICAL T4B ESOPHAGEAL CANCER

Abstract Backgroud Although induction followed by conversion surgery (CS) is potentially curative for T4b esophageal cancer, the optimal initial induction treatment is unclear. We conducted a multicenter randomized prospective phase 2 trial of chemoradiotherapy (CRT) versus chemotherapy (CT) as initial induction therapy for CS in clinical T4b esophageal cancer. We compared treatment effects, adverse events and survival. Methods Ninety-nine patients with T4b esophageal cancer were randomly allocated to chemoradiotherapy (Group A, n = 49) or CT (Group B, n = 50) as initial induction treatment. CRT consisted of radiation (50.4 Gy) with cisplatin and 5-fluorouracil. CT consisted of 2 cycles of docetaxel plus cisplatin and 5-fluorouracil (DCF). CRT or CT was followed by CS if resectable. If unresectable, the patient received the other treatment as secondary treatment. CS was performed if resectable after secondary treatment. The primary end point was 2-year overall survival. The Japan Registry of Clinical Trials (s051180164). Results In Group A, CS was performed in 34 (69%) and 7 patients (14%) after initial and secondary treatment. In Group B, CS was performed in 25 (50%) and 17 patients (34%) after initial and secondary treatment. The R0 resection rate after initial and secondary treatment was similar (78% vs 76%, P = 1.000). Adverse events including leukopenia, neutropenia, febrile neutropenia, and diarrhea were significantly more frequent in Group B. Group A had better histological complete response of the primary tumor (40% vs 17%, P = 0.028) and histological nodal status (P = 0.038). The 2-year survival rate was 55.1% (95% CI 41.1–68.3%) in the CRT group and 34.7% (95% CI 22.8–48.9%) in the CT group, although the difference was not significant (p = 0.11). Local and regional lymph node recurrence in patients undergoing R0 resection was significantly higher in CT group than CRT group (30% versus 8%, p = 0.03 and 37% versus 8%, p = 0.002, respectively). Conclusions The results of the present trial showed that upfront CRT was superior to upfront CT in terms of adverse effects, pathological effects and 2 year-overall survival as initial induction therapy for CS in clinical T4b esophageal cancer.

HER2-low metastases of HER2-negative primary tumors: a single institution analysis of intertumoral and internodal heterogeneity in node-positive breast cancer.

HER2 status in breast cancer is an essential parameter in individual therapeutic decision-making and is routinely assessed in primary tumors in accordance with international recommendations. Reports of HER2 heterogeneity raise the question of basing treatment decisions on HER2 status in metastases, if present. We investigated the degree and clinical implications of HER2 heterogeneity in lymph node-positive breast cancer. Because of recent recognition of therapeutic opportunities in this group of tumors, we especially focused on cases involving low-level HER2 expression. The HER2 status of primary tumors and of corresponding lymph node metastases was determined in archived material at the protein and gene levels using the gene- protein assay and interpreted in accordance with 2018 ASCO/CAP criteria. HER2-low status was defined as protein expression levels 1+ or 2+ with negative amplification status. We analyzed a series of 43 cases of primary infiltrating breast cancer, each with at least two axillary nodes harboring macrometastases (>2 mm), in total 206 such nodes. In 7% of cases, we detected intertumoral HER2 heterogeneity. Three of nine HER2-positive primary tumors were associated with HER2-negative metastases. No cases with HER2-negative primary tumors had HER2-positive metastases, but 55% (6/11) of HER2 0 primary tumors had HER2 1+ and/or 2+ metastases, and 19% (3/16) HER2 1+ cases had exclusively HER2 0 metastases. All metastases in HER2 2+ cases showed HER2-low protein expression levels. Internodal HER2 heterogeneity at low protein expression levels (presence of HER2 0, HER2 1+, and/or HER2 2+ metastatic deposits within the same axilla) was seen in 40% (17/43) of cases. We found no statistically significant association between HER2 heterogeneity and other tumor-related parameters. Survival data indicated worse outcomes in the HER2-low group compared with the rest of the cohort. Our results indicate a substantial instability of HER2 protein expression, leading to considerable intertumoral and internodal HER2 heterogeneity in lymph node-positive breast carcinomas. This heterogeneity is particularly relevant in HER2-low tumors in which the corrective effects of HER2 gene copy number analysis definitionally is absent. Our findings suggest that determining HER2 status in metastatic lymph nodes may generate relevant information for therapeutic decision-making.