High Risk Of Disease Recurrence Research Articles

Neoantigen DNA vaccines are safe, feasible, and induce neoantigen-specific immune responses in triple-negative breast cancer patients

Abstract Background Neoantigen vaccines can induce or enhance highly specific antitumor immune responses with minimal risk of autoimmunity. We have developed a neoantigen DNA vaccine platform capable of efficiently presenting both HLA class I and II epitopes and performed a phase 1 clinical trial in triple-negative breast cancer patients with persistent disease on surgical pathology following neoadjuvant chemotherapy, a patient population at high risk of disease recurrence. Methods Expressed somatic mutations were identified by tumor/normal exome sequencing and tumor RNA sequencing. The pVACtools software suite of neoantigen prediction algorithms was used to identify and prioritize cancer neoantigens and facilitate vaccine design for manufacture in an academic GMP facility. Neoantigen DNA vaccines were administered via electroporation in the adjuvant setting (i.e., following surgical removal of the primary tumor and completion of standard of care therapy). Vaccines were monitored for safety and immune responses via ELISpot, intracellular cytokine production via flow cytometry, and TCR sequencing. Results Eighteen subjects received three doses of a neoantigen DNA vaccine encoding on average 11 neoantigens per patient (range 4–20). The vaccinations were well tolerated with relatively few adverse events. Neoantigen-specific T cell responses were induced in 14/18 patients as measured by ELISpot and flow cytometry. At a median follow-up of 36 months, recurrence-free survival was 87.5% (95% CI: 72.7–100%) in the cohort of vaccinated patients. Conclusion Our study demonstrates neoantigen DNA vaccines are safe, feasible, and capable of inducing neoantigen-specific immune responses. Clinical trial registration number NCT02348320.

Safety and Efficacy of Neoadjuvant Docetaxel and Radiotherapy in Localized High-Risk Prostate Cancer: Results From a Prospective Pilot Study.

Approximately 15% of patients with localized prostate cancer are at high risk for disease recurrence. Many clinical trials have evaluated the impact of neoadjuvant therapy before radical prostatectomy with mixed results (NCT00321698). This phase I/II clinical trial evaluated the tolerability and preliminary efficacy of neoadjuvant radiation therapy and docetaxel before prostatectomy in 25 men with high-risk prostate cancer. The treatment regimen included 45Gy radiotherapy in 25 fractions to the prostate and seminal vesicles over 5 weeks, along with weekly dose-escalated docetaxel up to 30mg/m², followed by prostatectomy and bilateral lymph node dissection. The primary endpoint was the rate of pathologic complete response (pCR). Secondary endpoints included adverse events, symptom and quality of life measures, and prostate-specific antigen metrics. All 25 patients completed the planned treatment. The primary endpoint of pCR was not achieved. Lymphopenia was the most common grade 3 or higher toxicity, with no grade 3 or higher genitourinary or gastrointestinal toxicities observed. With a median follow-up of 11.6 years, the 10-year biochemical recurrence-free survival was 60%, and distant metastasis-free survival was 80%. Prostate cancer-specific survival and overall survival at 10 years were 84% and 60%, respectively. Although pCR was not met, the treatment demonstrated a modest toxicity profile and reasonable long-term outcomes, suggesting feasibility and safety. Further studies are needed to optimize endpoints and assess the efficacy of neoadjuvant treatments compared with standard approaches in high-risk prostate cancer patients.

Prognostic Significance of Angiogenesis in invasive ductal carcinoma

Background: Angiogenesis is essential for tumor growth and metastasis. Axillary lymphnode status has been the most important prognostic factor in operable breast carcinoma, but it does not fully account for the varied disease outcome. More accurate prognostic indicators would help in selection of patients at high risk for disease recurrence and death who are candidates for systemic adjuvant therapy. Microvessel density in invasive ductal carcinoma (measures of tumor angiogenesis) is associated with metastasis and thus may be a prognostic indicator. Objective: To correlate intratumoral and peritumoral angiogenic microvessel density with lymphnode metastasis in invasive ductal carcinoma. Material and Methods: It is a cross sectional observational study, carried out at the department of Pathology, BSMMU from January 2016 to December 2017. A total 48 mastectomy samples with axillary nodes from histologically confirmed invasive ductal carcinoma were included in this study. Weidner method was used for calculating micro vessels density. Sections examined to evaluate the density of angiogenic vessels by immuohistological stain with vWF expression in invasive breast cancer. Correlation between angiogenic vessels density with or without lymphnode metastasis was taken. Results: In this study angiogenic vessel count is more in the intratumoral area than peritumoural area. There was a positive significant correlation between lymphnode metastasis with micro vessel density in both peritumoral and intratumoral areas in Weidner method in vWF stain. J Shaheed Suhrawardy Med Coll 2023; 15(1): 59-65

Immunotherapy and Radiotherapy for Older Patients with Locally Advanced Non-Metastatic Non-Small-Cell Lung Cancer Who Are Not Candidates for or Decline Surgery and Chemotherapy: A Practical Proposal by the International Geriatric Radiotherapy Group.

The standard of care for locally advanced non-small-cell lung cancer (NSCLC) is either surgery combined with chemotherapy pre- or postoperatively or concurrent chemotherapy and radiotherapy. However, older and frail patients may not be candidates for surgery and chemotherapy due to the high mortality risk and are frequently referred to radiotherapy alone, which is better tolerated but carries a high risk of disease recurrence. Recently, immunotherapy with immune checkpoint inhibitors (ICIs) may induce a high response rate among cancer patients with positive programmed death ligand 1 (PD-L1) expression. Immunotherapy is also well tolerated among older patients. Laboratory and clinical studies have reported synergy between radiotherapy and ICI. The combination of ICI and radiotherapy may improve local control and survival for NSCLC patients who are not candidates for surgery and chemotherapy or decline these two modalities. The International Geriatric Radiotherapy Group proposes a protocol combining radiotherapy and immunotherapy based on the presence or absence of PD-L1 to optimize the survival of those patients.

Latrophilin-3 as a downstream effector of the androgen receptor induces urothelial tumorigenesis.

Emerging evidence indicates that androgen receptor (AR) signaling plays a critical role in the pathogenesis of male-dominant urothelial cancer. Meanwhile, latrophilins (LPHNs), a group of the G-protein-coupled receptor to which a spider venom latrotoxin is known to bind, remain largely uncharacterized in neoplastic diseases. The present study aimed to determine the functional role of LPHN3 (encoded by the ADGRL3 gene), in association with AR signaling, in urothelial tumorigenesis. In human normal urothelial SVHUC cells, AR overexpression and androgen treatment considerably increased the expression levels of ADGRL3/LPHN3, while chromatin immunoprecipitation assay revealed the binding of AR to the promoter region of ADGRL3. In SVHUC or SVHUC-AR cells with exposure to a chemical carcinogen 3-methylcholanthrene, LPHN3 activation via ligand (e.g., α-latrotoxin, FLRT3) treatment during the process of the neoplastic/malignant transformation or LPHN3 knockdown via shRNA virus infection induced or reduced, respectively, the oncogenic activity. In N-butyl-N-(4-hydroxybutyl)nitrosamine-treated female mice, α-latrotoxin or FLRT3 injection accelerated the development of bladder tumors. Immunohistochemistry in surgical specimens further showed the significantly elevated expression of LPHN3 in non-muscle-invasive bladder tumors, compared with adjacent normal urothelial tissues, which was associated with a marginally (p = 0.051) higher risk of disease recurrence after transurethral resection. In addition, positivity of LPHN3 and AR in these tumors was strongly correlated. These findings indicate that LPHN3 functions as a downstream effector of AR and promotes urothelial tumorigenesis.

New hopes and promises in the treatment of ovarian cancer focusing on targeted treatment-a narrative review.

Unfortunately, ovarian cancer is still diagnosed most often only in an advanced stage and is also the most lethal gynecological cancer. Another problem is the fact that treated patients have a high risk of disease recurrence. Moreover, ovarian cancer is very diverse in terms of molecular, histological features and mutations. Many patients may also develop platinum resistance, resulting in poor response to subsequent lines of treatment. To improve the prognosis of patients with ovarian cancer, it is expected to make better existing and implement new, promising treatment methods. Targeted therapies seem very promising. Currently, bevacizumab - a VEGF inhibitor and therapy with olaparib - a polyADP-ribose polymerase inhibitor are approved. Other methods worth considering in the future include: folate receptor α, immune checkpoints or other immunotherapy methods. To improve the treatment of ovarian cancer, it is also important to ameliorate the determination of molecular features to describe and understand which group of patients will benefit most from a given treatment method. This is important because a larger group of patients treated for ovarian cancer can have a greater chance of surviving longer without recurrence.

Toripalimab (anti-PD-1) plus recombinant human endostatin as adjuvant therapy in patients with resected stage III melanoma: Interim analysis of an open-label phase II trial.

e21557 Background: Patients with completely resected stage III melanoma are under high risk of disease recurrence. Recurrence-free survival (RFS) remains unsatisfactory despite there is adjuvant anti-PD-1 monotherapy following surgery, with the 1-year RFS about 70% and 2-year RFS about 49% in our country. It's urgent to explore combined regimens with anti-PD-1 to further improve the RFS. Here we report the interim efficacy and safety results of toripalimab (a PD-1 inhibitor) plus recombinant human endostatin (an angiogenesis inhibitor) as combined adjuvant therapy for patients with resected stage III melanoma. Methods: This prospective single-center, single-arm, open-label phase II trial screened adult patients with stage III melanoma who had undergone complete tumor resection within the previous 13 weeks for eligibility. Toripalimab was administrated in intravenous drip to patients at 3 mg/kg every 2 weeks in a 4-week cycle (day 1 and day 15 of each cycle), for up to 13 cycles or until disease recurrence, unacceptable toxicity or decease. Recombinant human endostatin was administrated in a continuous intravenous infusion at a dose of 210 mg from day 1 to day 3 for each 4-week cycle, for up to 6 cycles or until disease recurrence, unacceptable toxicity or decease. The primary endpoints were the 1-year and 2-year RFS. Results: By the data cut-off on Jan 25, 2024, 43 eligible patients with resected stage III melanoma between October 2021 and December 2023 were enrolled. In ITT population (n = 43), patients' median age was 56 (IQR 52~69) years. There were 25 (58%) male and 18 (42%) female; 27 (63%) with acral melanoma and 16 (37%) with cutaneous melanoma. With a median follow-up of 14 months, the 1-year and 2-year RFS rates were 83% and 71%, respectively. For security, 33 (77%) patients experienced at least one adverse event (AE), including 27 grade 1-2 AEs and 6 grade 3~4 AEs. One patient discontinued the combined therapy due to immunotherapy-associated myocarditis. Conclusions: Toripalimab in combination with recombinant human endostatin as adjuvant therapy could further improve disease-free survival in Chinese patients with completely resected stage III melanoma, with a manageable toxicity profile. Clinical trial information: 05907512 .

Prognostic significance of ctDNA mutation analysis in patients with HER2-positive breast cancer undergoing neoadjuvant chemotherapy.

e12654 Background: Neoadjuvant chemotherapy (NACT) combined with dual anti-HER2 agents followed by surgical resection is the standard treatment for stage II-III HER2- positive breast cancer (BC). Despite the availability of effective therapies such as ado-trastuzumab emtansine (T-DM1) and neratinib, identifying patients at high risk of disease recurrence remains challenging. To evaluate whether circulating tumor DNA (ctDNA) can be used as a biomarker to assess treatment response in patients with HER2-positive EBC treated with neoadjuvant anti-HER2 therapy. ctDNA burden can serve as a useful determinant for escalating or de-escalating (neo)adjuvant strategy in EBC patients. This study aimed to assess the role of ctDNA mutation analysis using low-pass whole-genome sequencing (lpWGS) and whole exome sequencing (WES) in evaluating blood copy-number burden (bCNB), genomic alterations, mutational signatures, blood tumor mutational burden (bTMB), and minimal residual disease (MRD) monitoring. Methods: A total of 46 HER2-positive BC patients who underwent NACT combined with dual anti-HER2 agents and surgical resection were enrolled, including 28 clinical stage II and 17 III patients. Plasma samples were collected at four time points: before NACT, after 3 cycles, at the completion of NACT, and after surgery. lpWGS was utilized to assess bCNB, while WES was performed to evaluate genomic alterations, mutational signatures, and bTMB. Mutations selected from the baseline sample were monitored for MRD. In cases where lpWGS yielded negative results, targeted NGS sequencing was conducted. Somatic mutations are identified by whole exome sequencing across 20,000 genes (with boosted sequencing coverage for 600 cancer-related genes). Between 4-50 personalized somatic mutations or fusions are selected for each patient. This personalized panel together with a fixed MRD core panel is utilized for MRD detection and monitoring. Results: Among the enrolled patients, nodal metastasis was observed in 29 patients and 29 were hormone receptor-positive, and 36 achieved pCR (78.2%). Positive ctDNA was detected 58.8% of patients. Higher nodal stage was associated with ctDNA positivity at baseline. MRD positivity after chemotherapy was observed in 4 patients and 2 patients achieved pCR TP53 was the most frequently altered gene, followed by PIK3CA, MAP3K1, REV3L, MYC, MAP2K4, ERBB3, ATRX, ATM and ALK. This pattern is comparable to that observed in previous studies on BC. Non-PCR patients commonly exhibit MAP3K1 and MAP2K4 alteration is their ctDNA. Conclusions: The identification of MRD, regardless of pCR status, can be valuable for risk stratification and personalized treatment decision-making. Further studies are warranted to validate these findings and explore the clinical implications of ctDNA mutation analysis in HER2-positive BC management.

Use of early circulating tumour DNA dynamics in patients with stage III melanoma receiving neoadjuvant combination immunotherapy.

9577 Background: Neoadjuvant therapy in resectable stage III cutaneous melanoma improves relapse-free survival compared to adjuvant therapy alone and is now a standard of care.While pathological response can help predict recurrence risk and the need for further treatment, more biomarkers are required. We investigated circulating tumour DNA (ctDNA) as a predictive biomarker for recurrence in stage IIIB/C melanoma patients following neoadjuvant immunotherapy and surgery. Methods: We retrospectively analysed plasma samples collected at baseline and six weeks post-surgery from 30 patients enrolled in the OpACIN-neo and PRADO clinical trials, who received two cycles of ipilimumab (anti-CTLA-4) and nivolumab (anti-PD-1) before surgery. Cell free DNA (cfDNA) underwent pre-amplification followed by tumour-informed mutation detection analysis using droplet digital polymerase chain reaction (ddPCR) with the Bio-Rad QX600 PCR system. BRAF mutations were identified in 60% of patients through tumour tissue sequencing. Following neoadjuvant therapy, 7/30 (23%) achieved complete pathological response (pCR), 5/30 (17%) near pCR, 4/30 (13%) partial response, and 14/30 (47%) non-response (pNR). Results: Baseline ctDNA was detectable in 15/30 (50%) patients using the pre-amplification ddPCR method. At median follow-up of 47 months, 9/30 (30%) patients recurred, with a median time to recurrence of 8 months (range 6 to 29 months). Post-surgery, ctDNA was detectable in 4/9 patients who recurred; all four were pathological non-responders and recurred with distant, unresectable disease. Among the 15 ctDNA-positive patients at baseline, 13/15 (87%) patients achieved ctDNA clearance while 2/15 (13%) remained persistently ctDNA-positive; with a subsequent relapse rate of 0% and 100% respectively. ctDNA detection post-surgery predicted patients at higher risk of disease recurrence [relapse-free survival (RFS) hazard ratio (HR) 7.83, 95%CI 0.82-74.48; p=0.0002] and poorer melanoma-specific survival (MSS) [HR 6.35, 95% CI 0.36-110.70; p=0.0337]. Conclusions: Post-surgery ctDNA positivity can signal imminent recurrence, thus offering a window for personalised adjuvant therapy modification.

Abstract PO3-08-09: Unique molecular signatures of germline mutations in low expression of human epidermal growth factor receptor 2 (HER2) breast cancer

Abstract Background: Overexpression of human epidermal growth factor receptor 2 (HER2) in breast cancer (BC) is associated with lower survival and higher risk of disease recurrence. A new subtype of HER2-low BC which has been proposed from several studies demonstrates that HER2-low patients have distinct somatically genetic alterations and clinical outcomes. We have previously reported that HER2-low BC had distinct clinical and somatic mutational feature compared with HER2-zero and HER2-high tumors. We have therefore extended studies by comparing germline mutation expression among these HER2 subgroups. Methods: 530 Chinese women with BC were enrolled in a prospective protocol between May 2021 to March 2023 at Guangdong Provincial People's Hospital. Genomics data was generated from a gene panel that surveys 102 tumor mutations. Germline variants were classified into pathogenic (P), likely pathogenic (LP), variant of uncertain significance (VUS), likely benign (LB) and benign (B) groups according to the ACMG/AMP Standards and Guidelines. The cohort was divided into three groups based on HER2 status as HER2-zero (n = 107), HER2-low (n = 259), and HER2-high (n = 127) according to immunohistochemistry and/or fluorescence in situ hybridization results. Results: The most common mutated genes were ATM, FANCD2, ATR, BRACA2, RECQL4 and APC. A total of 71 pathogenic or likely pathogenic (P/LP) mutations were identified in 25 cancer susceptibility genes from 64 patients (12.16%). The most frequent mutated P/LP genes are BRCA2, BRCA1, PALB2, PMS2, MUTYH and PTEN in the HER2-low group; BRCA2, BRCA1 and PALB2 in the HER2-zero cohort; Interestingly, among the nine HER2-high patients, we detected unique P/LP genes in each sample including MRE11, FANCM, ATM, FLCN, NTRK1, TP53, BRCA1, CHEKE2 and FANCA. In addition to P/LP mutations, 751 variants of uncertain significance (VUS) in 95 cancer susceptibility genes were also detected in 361 patients (68.11%). The most frequent mutated VUS mutations occurred genes are FANCD2, ATM, RECQL4, RAD54B and ATR in HER2-low group; ATM, FANCA, POLE, MSH2 and FANCD2 in HER2-zero cohort; and ATM, BRCA2, RECQL4, POLE, FANCI and FANCM for HER2-high patients. Most of mutated genes were homologous recombination repair (HRR) or DNA damage repair (DDR) pathway related genes. Several genes were differentially altered across HER2 subgroups, including the mutation frequency of the BMPR1A (p=0.0344), MSH2 (p=0.0103), and RAD51C (p=0.0336) genes that were significantly higher in HER2-zero group. It’s worth noting that RAD51C was only mutated in HER2-zero subgroup. BMPR1A and MSH2 were also mutated in HER2-low patients. Differentially mutated genes in specific HER2 subgroups may contribute to better research and choice of future therapeutic approaches. In 115 patients who received neoadjuvant therapy and 84 of them were evaluable for pathological response data, HER2-low patients had lower pathological complete response (pCR) rates than HER2-zero and HER2-high subgroups (p=0.0008). In particular, DDR pathway gene ERCC1 have significantly higher mutation frequency in pCR patients (p=0.0115). Conclusion: HER2-low BC patients have distinct germline mutational signatures and differential clinical outcomes under neoadjuvant systemic therapy. These results have provided additional evidence that HER2-low patients comprise a fourth subtype of BC that needs to be accounted for separately in terms of clinical treatment and outcome reporting. Keywords: breast cancer, germline mutations, human epidermal growth factor receptor 2 (HER2), HER2-low, targeted therapy, next-generation sequencing Table 1. List of most frequent mutated genes in HER2-zero, HER2-low and HER2-high groups Citation Format: Ning Liao, Weiqi Zhang, Liangqiu Liu, Wendy Wu, Siqi Wang, Li Cao, Jianguo Lai, Xueying Zhang, Airong Yang, Yulei Wang, Cheukfai Li, Guochun Zhang, Chongyang Ren, Lingzhu Wen. Unique molecular signatures of germline mutations in low expression of human epidermal growth factor receptor 2 (HER2) 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 PO3-08-09.

Abstract PO3-02-01: Educational Opportunities to Improve Community Healthcare Professionals’ Management of High-Risk HR-Positive/HER2-Negative Early Breast Cancer

Abstract Background: The treatment landscape for patients with hormone receptor–positive/HER2-negative early breast cancer (HR+/HER2- EBC) has evolved with the emergence of adjuvant CDK4/6 inhibitor therapy as a new option for patients with a high risk of disease recurrence. Adjuvant abemaciclib plus aromatase inhibitors (AIs) is guideline recommended for high clinical risk HR+ disease and reduces risk of recurrence regardless of Ki-67 expression level. Here, we examine healthcare professionals’ (HCPs’) awareness and practice regarding the use of adjuvant abemaciclib. Methods: Between November 2022 and June 2023, we conducted a series of regional educational activities for HCPs focused on management of high-risk HR+/HER2- EBC. Each activity included an interactive lecture led by a clinical investigator with expertise in managing patients with high-risk HR+/HER2- EBC and polling questions designed to assess key aspects of HCP knowledge and practice in the optimal management of high-risk HR+/HER2- EBC. A wider HCP audience was able to view an interactive on-demand webcast with the same content and embedded polling questions. Results: In total, 701 HCPs participated in one of 20 live (n = 373) activities or the one associated on-demand (n = 328) webcast. The distribution of HCP participation differed between the live and online activities with more physicians participating in the online activity vs the live activity (59% vs 34%, respectively); the converse was true for nurse participation (9% online vs 34% live). Polling result trends were similar between the live and online activities. At baseline, 38% (n/N = 182/405) of HCPs chose adjuvant therapy with an AI plus abemaciclib for a patient with high-risk, node-positive HR+/HER2- EBC consistent with expert and guideline recommendations. Following the education, 92% (n/N = 405/439) of HCPs selected AI plus abemaciclib for appropriate patients. Before education, 32% of HCPs (n/N = 147/454) were aware that adjuvant abemaciclib plus endocrine therapy improved invasive disease-free survival compared with endocrine therapy alone in patients with high-risk, node-positive HR+/HER2- EBC regardless of Ki-67 expression level, which increased to 87% (n/N = 370/425) following the education. Regarding the management of grade 2 neutropenia associated with adjuvant abemaciclib therapy, HCP knowledge was low at baseline (32%, n/N = 141/446) and improved to 80% (n/N = 332/415) after education. Conclusions: HCPs’ knowledge of and practice concerning adjuvant abemaciclib as a newer approved therapy for patients with high-risk HR+/HER2- EBC remain suboptimal. These results suggest an ongoing need for expert guidance and educational activities on the use of adjuvant abemaciclib therapy for appropriate patients with high-risk HR+/HER2- EBC. As the treatment landscape for HR+/HER2- EBC continues to evolve with the potential approval of additional new therapies, this need will only increase with a clear impact on optimizing and individualizing adjuvant therapy strategies for patients with HR+/HER2- EBC. Citation Format: Marie Becker, Timothy Quill, Erika Hamilton, Joyce O'Shaughnessy. Educational Opportunities to Improve Community Healthcare Professionals’ Management of High-Risk HR-Positive/HER2-Negative 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 PO3-02-01.

Abstract PO2-13-07: SMARCA2 compensation of SMARCA4 loss mediates adaptive resistance to neoadjuvant systemic therapy in triple-negative breast cancer: paired transcriptomic analysis of pre- and post-treatment samples from NeoSTOP and NeoPACT

Abstract Objectives/Rationale: Triple-negative breast cancer (TNBC) patients with residual disease (RD) after neoadjuvant systemic therapy (NAST) are at high risk for disease recurrence and death. While multiple prognostic biomarkers associated with response to NAST have been identified, adaptive resistance mechanisms to NAST remain poorly understood. Identifying and characterizing adaptive resistance mechanisms can illuminate novel therapeutic approaches and improve outcomes for TNBC patients with RD. Methods: Total RNA was isolated from pre-treatment and paired surgical specimens (for patients with RD) from TNBC patients treated with chemotherapy on the NeoSTOP (NCT02413320) or chemoimmunotherapy on the NeoPACT (NCT03639948) neoadjuvant trials and was subjected to RNA exome sequencing. Comparative marker selection analysis was performed by computing the two-sided paired samples t-test for each gene followed by pre-ranked gene set enrichment analysis (GSEA) amongst 23,797 annotated gene sets. Gene sets with false-discovery rate (FDR) corrected P values < 0.001 were determined to be significant. Results: Pre-treatment sequencing data were available for N=200 patients and the overall pathologic complete response (pCR) rate was 56.5%. Paired pre- and post-treatment sequencing data were available for N=58 patients with RD (N=27 from NeoSTOP and N=31 from NeoPACT). 165/23,797 gene sets were significantly enriched in post-treatment compared to pre-treatment samples. SHEN_SMARCA2_TARGETS_UP (M29) was among the top five significantly enriched gene set and was selected for further analysis based on the known role of the SWI/SNF complex in cell survival and the availability of clinically viable SMARCA2 degraders. Pre-treatment SMARCA4 expression was associated with pCR, with lower median expression noted in patients with RD compared to patients who achieved pCR (P=0.04). Pre-treatment SMARCA2 expression was not associated with pCR (P=0.48). On paired sample analysis there was pronounced downregulation of SMARCA4 in post-treatment compared to pre-treatment samples in all patients (mean Z=-1.46, P< 0.0001), in patients treated with chemotherapy (mean Z=-1.65, P< 0.0001), and in patients treated with chemoimmunotherapy (mean Z=-1.28, P< 0.0001). Although there was no difference in SMARCA2 expression between paired pre- and post-treatment samples (mean Z=0.03, P=0.83), there was enrichment of SMARCA2 target expression on GSEA analysis (NES=2.63, FDR q< 0.00001) indicating that SMARCA2 activity is compensating for therapy-induced SMARCA4 loss. Conclusions: We identified 165 gene sets that were significantly enriched in paired post-treatment compared to pre-treatment TNBC samples. Altered activity of the SMARCA2 subunit of the SWI/SNF chromatin remodeling complex was identified as one of the top hits. SMARCA2 and SMARCA4 are mutually exclusive subunits of SWI/SNF, and inactivation of both SMARCA2 and SMARCA4 is synthetic lethal. We observed an association of lower pre-treatment SMARCA4 expression with resistance to NAST and pronounced therapy-induced downregulation of SMARCA4 and induction of SMARCA2 target genes in post-treatment compared to pre-treatment samples, suggesting that SMARCA2 compensates for adaptive SMARCA4 loss. SMARCA2 degraders are in early-phase clinical trials and are known to induce synthetic lethality in SMARCA4-deficient cells. Our results identify adaptive loss of SMARCA4 and synthetic lethal targeting of compensatory SMARCA2 as an attractive therapeutic target in TNBC patients with RD after neoadjuvant chemotherapy or chemoimmunotherapy. Citation Format: Shane Stecklein, Rachel Yoder, Joshua Staley, Zachary Schmitt, Anne O'Dea, Lauren Nye, Deepti Satelli, Gregory Crane, Rashna Madan, Maura O'Neil, Andrew Godwin, Harsh Pathak, Qamar Khan, Joyce O'Shaughnessy, Priyanka Sharma. SMARCA2 compensation of SMARCA4 loss mediates adaptive resistance to neoadjuvant systemic therapy in triple-negative breast cancer: paired transcriptomic analysis of pre- and post-treatment samples from NeoSTOP and NeoPACT [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 PO2-13-07.

Investigating locations of recurrences with MRI after CRS-HIPEC for colorectal peritoneal metastases

PurposePatients with colorectal peritoneal metastases (PM) treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are at high risk of recurrent disease. Understanding where and why recurrences occur is the first step in finding solutions to reduce recurrence rates. Although diffusion-weighted (DW) MRI is not routinely used in the follow-up of CRC patients, it has a clear advantage over CT in detecting the location and spread of (recurrent) PM. This study aimed to identify common locations of recurrence in CRC patients after CRS-HIPEC with MRI. MethodThis was a single-centre retrospective study of patients with recurrent PM after CRS-HIPEC performed between January 2016 and August 2020. Patients were eligible for inclusion if they had both an MRI preoperatively (MRI1) and at the time of recurrent disease (MRI2). Two abdominal radiologists reviewed in consensus and categorized recurrences according to their location on MRI2 and in correlation with previous disease location on prior imaging (MRI1) and the surgical report of the CRS-HIPEC. ResultsThirty patients were included, with a median surgical PCI of 7 (range 3–21) at the time of primary CRS-HIPEC. In total, 68 recurrent metastases were detected on MRI2, of which 14 were extra-peritoneal. Of the remaining 54 PM, 42 (78%) occurred where the peritoneum was damaged due to earlier resections or other surgical procedures (e.g. inserted surgical abdominal drains). Most recurrent metastases were found in the mesentery, lower abdomen/pelvis and abdominal wall (87%). ConclusionsMost recurrent PMs appeared in the mesentery, lower abdomen/pelvis and abdominal wall, especially where the peritoneum was previously damaged.

Late-onset lymphopenia during radiation is associated with an increased risk of tumor recurrence in newly diagnosed pediatric medulloblastoma.

Recent data found a correlation between lymphopenia occurring early during craniospinal radiation therapy (RT) and risk of disease recurrence in newly diagnosed childhood medulloblastoma. However, the population included patients who received chemotherapy prior to or during RT. Here, we investigate the effect of lymphopenia during RT in patients with newly diagnosed pediatric medulloblastoma who were chemotherapy-naïve. We analyzed 79 patients with newly diagnosed medulloblastoma (ages 2-21years) treated between 1997 and 2013 with craniospinal RT. Log-rank tests were used to determine survival differences, and Cox proportional hazards regression was used to assess associations between patient characteristics and lymphopenia with disease recurrence risk. Eighty-three percent of patients (62/75) had grade ≥3 lymphopenia by RT Week 3, with 95% developing grade ≥3 lymphopenia at some point during therapy. There was no difference in incidence of lymphopenia between those who received proton beam RT (93%) versus photon (97%). Twenty-four of 79 (30%) patients developed disease recurrence at an average 27.0months after diagnosis. There was higher risk of disease recurrence in patients with grade ≥3 lymphopenia during RT Week 4 (log-rank p=.016; Cox p=.03) and Week 5 (log-rank p=.024; Cox p=.032); after adjusting for clinical risk group, only grade ≥3 lymphopenia at Week 4 remained prognostic (Cox p=.04). No correlation was found between risk of tumor recurrence and early lymphopenia (RT Weeks 0-3) or absolute lymphocyte count (ALC) below the median at any time during RT. Lymphopenia during RT Weeks 4 and 5 correlates with increased risk of tumor recurrence in pediatric patients with newly diagnosed medulloblastoma.

It Is What the Surgeon Does Not See That Kills the Patient.

Patients with colon cancer may present at multiple different stages of the disease process. Many patients can be cured of colon cancer as a result of a simple surgical procedure usually performed by minimally invasive techniques. However, there are a variable number of patients, estimated at approximately 10%, who have a more advanced disease. If these patients are treated by the current conventional standard of care, the likelihood for treatment failure is extremely high. These are not patients with known disseminated disease but patients who are at high risk of recurrent disease unless special treatments are initiated preoperatively and intraoperatively. The identification of these patients is by (1) a high-quality CT scan, (2) tumor markers found preoperatively, (3) colonoscopic findings, and (4) symptoms. Patients identified as being at high risk require special preoperative treatments which include neoadjuvant chemotherapy. Intraoperative chemotherapy with HIPEC should occur as part of the treatment if peritoneal metastases are documented by biopsy. In the operating room, a thorough exploration of all possible occult peritoneal spaces for metastatic disease needs to be performed. A modified cytoreductive surgical procedure along with a colon resection is performed in order to minimize sites of occult peritoneal metastases. This includes the greater omentum, ovaries, and tubes in postmenopausal women. Peritonectomy is used to create a shroud around the tumor so that all peritoneum that has been in direct contact with the tumor surface is resected and is used as a barrier against tumor cell dissemination in the process of colon cancer resection. If peritoneal metastases are visualized at any site, HIPEC should be included as part of the treatment package. I am convinced that patients at high risk of recurrence will have an improved outcome with proper preoperative evaluation, preoperative neoadjuvant chemotherapy, and a revised intraoperative management strategy.

CtDNA as an Adjunct to Posttreatment PET for Head and Neck Cancer Recurrence Risk Assessment.

Circulating tumor DNA (ctDNA) detection is an emerging technique that identifies minimal residual disease in patients with solid tumors. ctDNA can act as an adjunct method to help overcome the limitations of positron emission tomography (PET) and select patients who are at high risk for recurrence. Retrospective Single Institutional Study. University Hospital Setting. Twenty-nine patients who underwent definitive treatment for squamous cell carcinoma of the head and neck (HNSCC) from 8/2021 to 01/2023 had ctDNA levels analyzed at 1 to 3, 6, 9, and 12 months after definitive treatment. A personalized, tumor-informed, multiplex polymerase chain reaction (PCR) next-generation sequencing (NGS) assay was used to detect the ctDNA levels. The primary outcome was recurrence-free probability (RFP), and the secondary outcomes were overall survival (OS), sensitivity, specificity, and the test's negative (NPV) and positive predictive values (PPV). The median age of patients was 65 years (interquartile range: 56-69), with majority being males (n = 22, 76%). The primary sites were larynx (n = 12), oropharynx (n = 10), and oral cavity (n = 6). Posttreatment ctDNA was detected in 7 patients, all of whom had disease recurrence. ctDNA detection after definitive treatment was associated with a higher risk of disease recurrence (hazard ratio: 9.94, 95% confidence interval: 1.56-63.3, P = .015). ctDNA identified recurrence with 100% specificity and 78% sensitivity. The NPV and PPV were 91% and 100%. PET had 78% sensitivity but only 68% specificity with 86% NPV, and 54% PPV. Based on our data, ctDNA can be an excellent adjunct test for posttreatment PET and can help guide physicians in cases where PET results are inconclusive and difficult to interpret.

Abstract 4995: Impact of radiotherapy on extracellular vesicle mediated anti-tumor immunity in oligometastatic prostate cancer

Abstract Metastasis-ablative radiotherapy is a new therapeutic approach that prolongs survival in patients with advanced cancers. Tumour irradiation can elicit an immunogenic cell death resulting in the expansion of tumour-reactive T cells and eradication of both irradiated and distant non-irradiated metastases, referred to as the “abscopal effect”. This abscopal response, nevertheless, is observed in a minority of patients suggesting uncharacterized mechanisms that prevent robust systemic anti-tumor immune response. Tumour-derived extracellular vesicles (TdEVs) have recently emerged as mediators of antitumor immunity but their immunomodulatory role in response to radiotherapy remains largely unknown. Recent clinical studies by our lab have demonstrated that circulating levels of tumour-derived extracellular vesicles (tdEVs) are elevated in response to radiotherapy and high tdEV concentrations are associated with reduced levels of peripheral cytotoxic CD8+ T cells and higher risk of disease recurrence in advanced prostate cancer. Based on our findings, we hypothesize that radiotherapy induces the release of tumor-derived EVs that suppress anti-tumor immunity. Prostate cancer cells (PC3 and DU145) were irradiated with clinically used doses of ionizing radiation (20Gy x 1 or 10Gy x 3 fractions) and tdEVs were co-cultured with human CD8+ T cells to measure their proliferation and cytotoxic activity. Increased levels of tdEVs were released by tumour cells treated with radiotherapy. A higher frequency of impaired T cell cytotoxic activity and a reduction in CD8 T cell proliferation was found in the 10Gy x 3 radiation regimen. Proteomic analysis and western blot showed an increased expression of the immune checkpoint molecule B7-H3 on the tumour cell surface and tdEVs in response to radiotherapy. While coculture of CD8 T cells with B7-H3 depleted tdEVs led to recovery of T-cell cytotoxic ability, overexpression of the B7-H3 in tdEVs inhibited cytotoxic activity. This study provides a rationale for future studies in which we will test the immune-mediated effects of radiotherapy-induced tdEVs in immunocompetent mouse models and investigate B7-H3 blockade as a therapeutic approach to boost abscopal response in the treatment of advanced prostate cancer. Citation Format: Chisom J. Uzendu, Yohan Kim, Roxane R. Lavoie, Haidong Dong, Sean Park, Fabrice Lucien-Matteoni. Impact of radiotherapy on extracellular vesicle mediated anti-tumor immunity in oligometastatic prostate cancer [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 4995.

Predictors of disease recurrence after radical resection and adjuvant chemotherapy in patients with stage IIb-IIIa squamous cell lung cancer: A retrospective analysis.

Lung cancer (LC) is a global medical, social and economic problem and is one of the most common cancers and the leading cause of mortality from malignant neoplasms. LC is characterized by an aggressive course, and in the presence of disease recurrence risk factors, patients, even at an early stage, may be indicated for adjuvant therapy to improve survival. However, combined treatment does not always guarantee a favorable prognosis. In this regard, establishing predictors of LC recurrence is highly important both for determining the optimal treatment plan for the patients and for evaluating its effectiveness. To establish predictors of disease recurrence after radical resection and adjuvant chemotherapy in patients with stage IIb-IIIa lung squamous cell carcinoma (LSCC). A retrospective case-control cohort study included 69 patients with LSCC who underwent radical surgery at the Orenburg Regional Clinical Oncology Center from 2009 to 2018. Postoperatively, all patients received adjuvant chemotherapy. Histological samples of the resected lung were stained with Mayer's hematoxylin and eosin and examined under a light microscope. Univariate and multivariate analyses were used to identify predictors associated with the risk of disease recurrence. Receiver operating characteristic curves were constructed to discriminate between patients with a high risk of disease recurrence and those with a low risk of disease recurrence. Survival was analyzed using the Kaplan-Meier method. The log-rank test was used to compare survival curves between patient subgroups. Differences were considered to be significant at P < 0.05. The following predictors of a high risk of disease recurrence in patients with stage IIb-IIa LSCC were established: a low degree of tumor differentiation [odds ratio (OR) = 7.94, 95%CI = 1.08-135.81, P = 0.049]; metastases in regional lymph nodes (OR = 5.67, 95%CI = 1.09-36.54, P = 0.048); the presence of loose, fine-fiber connective tissue in the tumor stroma (OR = 21.70, 95%CI = 4.27-110.38, P = 0.0002); and fragmentation of the tumor solid component (OR = 2.53, 95%CI = 1.01-12.23, P = 0.049). The area under the curve of the predictive model was 0.846 (95%CI = 0.73-0.96, P < 0.0001). The sensitivity, accuracy and specificity of the method were 91.8%, 86.9% and 75.0%, respectively. In the group of patients with a low risk of LSCC recurrence, the 1-, 2- and 5-year disease-free survival (DFS) rates were 84.2%, 84.2% and 75.8%, respectively, while in the group with a high risk of LSCC recurrence the DFS rates were 71.7%, 40.1% and 8.2%, respectively (P < 0.00001). Accordingly, in the first group of patients, the 1-, 2- and 5-year overall survival (OS) rates were 94.7%, 82.5% and 82.5%, respectively, while in the second group of patients, the OS rates were 89.8%, 80.1% and 10.3%, respectively (P < 0.00001). The developed method allows us to identify a group of patients at high risk of disease recurrence and to adjust to ongoing treatment.

Outcomes of elderly patients with node-positive colon cancer: A multi-center population-based cohort study.

33 Background: Patients with stage III colon cancer are at high risk of recurrent disease. In this large population based cohort study we examined prognostic significance of chemotherapy and other clinical, pathological &amp; contextual variables that are associated with inferior outcomes in elderly patients with stage III colon cancer. Methods: Patients ≥ 70 years with stage III colon cancer diagnosed in Saskatchewan, a Canadian province, and underwent resection of the primary tumor during 2012-2018 were evaluated. A Cox proportional multivariate survival analysis was performed to determine factors correlated with overall survival (OS) and disease-free survival (DFS). Results: 404 eligible patients with median age of 79 yrs &amp; M:F of 1:1 were identified. 48% were ≥80 years, 60% were rural resident, 66% had ≥ 1 major comorbid illness, 34% had WHO performance status &gt;1, 14% has an ostomy formation, 46% had a T4 or N2 high-risk disease, and 50% had node positive to node harvested (NPNH) ratio of &gt;0.1. 43% patients received adjuvant chemotherapy. Median time to start chemo was 9 weeks. Patients who did not receive adjuvant chemotherapy were significantly older, had low performance status or experienced high rate of post-operative complications, high serum creatinine, low albumin, anemia, elevated WBC count and platelets. Median OS of all patients was 51 months (95%CI: 42.4-59.6), with estimated 5 &amp; 10-yr OS of 45% and 30%. Median DFS of entire cohort was 32 months (26.3-37.7) with 5 &amp; 10-yr DFS of 34% and 20%. Patients who received adjuvant chemotherapy had median OS of 106 months (83.8-128.5) vs. 30 months (23.4-36.6), p&lt;0.001 with 5 &amp; 10-yr OS of 64% and 49% vs. 31% and 19% (p&lt;0.001). Patients who received adjuvant chemotherapy had median DFS of 56 months (28.2-83.9) vs. 22 months (16.5-27.5), p&lt;0.001 with 5 &amp; 10-yr DFS of was 49% and 30% vs. 24% and 13% (p=&lt;0.001). The Cox-multivariate analysis revealed a past history of cancer, HR, 1.32 (1.03-1.72); ostomy, HR, 1.33 (1.02-1.74); NPNH ratio &gt;0.1, 1.34 (1.04-1.78); grade III tumor, 1.36 (1.04-1.78); WHO performance status &gt;1, HR, 1.38 (1.05-1.82); no adjuvant chemo, HR, 1.38 (1.03-1.85); high-risk stage III disease, HR, 1.39 (1.10-1.79), and baseline CEA &gt;5, HR, 1.75 (1.34-2.29), were independently correlated with DFS whereas past history of cancer, HR, 1.47 (1.12-1.94); ostomy, HR, 1.53 (1.16-2.03); NPNH ratio &gt;0.1, 1.51 (1.15-1.98); grade III tumor, 1.54 (1.16-2.04); WHO performance status &gt;1, HR, 1.42 (1.06-1.90); no adjuvant chemo, HR, 1.82 (1.32-2.50); high-risk stage III disease, HR, 1.60 (1.22-2.11), and CEA &gt;5, HR, 1.98 (1.50-2.61) were independently correlated with OS. Conclusions: In elderly patients with stage III colon cancer lack of adjuvant chemotherapy, poor performance status, T4 or N2 disease, grade III tumor, elevated baseline CEA, past history of a secondary cancer, elevate NPNH ratio &gt;0.1 and an ostomy formation correlate with inferior outcomes.

Advisory board resolution: The role of the adjuvant atezolizumab plus bevacizumab in patients with hepatocellular carcinoma at high risk of recurrence following surgical resection or ablation

MEETING DATE: July 7, 2023ITEMS ON THE AGENDA:1. The role of the adjuvant atezolizumab plus bevacizumab in patients with hepatocellular carcinoma (HCC) at high risk of recurrence following surgical resection or ablation. Profile of the patient who will benefit the most from this therapy.2. To evaluate the prospects for therapeutic options for patients with early HCC in Russia.Liver cancer remains a public health concern globally, with an increasing trend in the number of incident cases worldwide. Early, precise diagnosis and timely treatment contribute to the improvement in overall and relapse-free survival. It is important that the entire arsenal of local treatments (resection, ablation and liver transplantation) can be applied in cases when HCC is detected at a very early and early stage of the disease. Tumour recurrence after surgical treatment or ablation is a complex and underexplored problem in the treatment of patients with HCC. Many factors that can predict the risk of relapse after surgical treatment have been described: tumour size &gt;5 cm, &gt;3 foci, micro- or macrovascular (Vp1-2) invasion, poor degree of tumour differentiation (G3-4). Our advisory board tried to identify the most important risk factors for early relapse, and to determine the role and impact of the results of the first positive clinical trial focused on the issue of early HCC, IMbrave050: a phase 3 trial of adjuvant atezolizumab + bevacizumab vs active surveillance in patients with HCC at high risk of disease recurrence following resection or ablatio.