Shilpakar, Ramila

10513 Background: Prior reports of high frequency of BRCA1 and BRCA2 ( BRCA1/2 ) PVs among South Asian women from Bangladesh, India, Nepal, and Pakistan with breast or ovarian cancer require validation in large prospective unselected cohorts. Methods: Individual-level anonymized patient data from two prospective cohorts were pooled to evaluate the prevalence of germline PVs among South Asian women: the South Asian Regional Alliance for Hereditary Cancers (SARAH Consortium) in Bangladesh, Nepal, and Pakistan, and the previously reported Nurse-led Genetic Counseling and Awareness (NuGenA) expansion cohort in India. Both studies enrolled consecutive cases of histologically confirmed newly diagnosed breast or epithelial ovarian cancer irrespective of age at diagnosis or family history. In both studies, participants completed questionnaires on personal and family history (first-, second- or third-degree) and provided blood for germline genetic testing after written consent. PVs in cancer predisposition genes including ATM, BARD1, BRCA1, BRCA2, BRIP1, CHEK2, MLH1, MSH2, MSH6, PALB2, RAD51C, RAD51D, and TP53 were identified as part of the studies utilizing a multigene panel and the results were returned to ordering clinicians. The data cutoff date for this analysis was November 30, 2025. Results: The analysis included 1,711 South Asian women with breast (n=1,210) or ovarian (n=501) cancer. A family history of breast or ovarian cancer was noted in 177 (10.3%). Among breast cancers, 94% were invasive, 84% were ductal, 35% were triple-negative and over two-thirds presented with nodal involvement. Germline PVs across 13 predisposition genes were observed in 17.7% of breast and 35.9% of ovarian cancers. Notably, BRCA1/2 PVs accounted for most of these PV (13.6% of breast and 28.3% of ovarian cancer cases) with PVs in all genes except BRCA1/2 under 1%. The frequency of BRCA1/2 PVs was 24.4% in triple-negative breast cancer and 8.0% in ER+/HER2-. BRCA1/2 PV carriers were diagnosed with breast cancer at a younger age than non-carriers (Median age: 42 vs 46 years, P<0.001), with no age difference observed in ovarian cancer (50 vs. 51 years, P=0.79). Notably, among the 306 BRCA1/2 PV carriers identified, 229 (74.2%) did not report a family history of breast or ovarian cancer. Conclusions: We confirm a high prevalence of BRCA1/2 PVs among unselected South Asian women with either breast or ovarian cancer. The observations of younger age at cancer diagnosis, and low rates of family history support the need for population-specific germline genetic testing and risk management strategies in South Asia.

PURPOSE Accurate understanding of the genomic and transcriptomic data provided by next-generation sequencing (NGS) is essential for the effective utilization of precision oncology. Molecular tumor boards (MTBs) aim to translate the complex data in NGS reports into effective clinical interventions. Often, MTB treatment recommendations differ from those in the NGS reports. In this study, we analyze the discordance between these recommendations and the rationales behind the discordances, in a non–high-income setting, with international input to evaluate the necessity of MTB in clinical practice. METHODS We collated data from MTB that were virtually hosted in Chennai, India. We included patients with malignancies who had NGS reports on solid tissue or liquid biopsies, and excluded those with incomplete data. MTB forms and NGS reports of each clinical case were analyzed and evaluated for recommendation concordance. Concordance was defined as an agreement between the first recommendation in the MTB forms and the therapeutic recommendations suggested in the NGS report. Discordance was the absence of the said agreement. The rationales for discordance were identified and documented. RESULTS Seventy MTB reports were analyzed with 49 cases meeting the inclusion criteria. The recommendation discordance was 49% (24 of 49). Discordant recommendations were mainly due to low level of evidence for the drug (75% of cases). CONCLUSION The discordance between MTB and NGS vendor recommendations highlights the clinical utility of MTB. The educational experiences provided by this initiative are an example of how virtual academic collaborations can enhance patient care and provider education across geographic borders.

e15050 Background: Molecular tumour boards (MTB) facilitate discussions among medical professionals, scientists, bioinformaticians and geneticists for clinical application of precision oncology, via interpretation of various genomic sequencing studies, most commonly Next Generation Sequencing (NGS). NGS test vendor recommendation may differ from the MTB recommendations. We aim to study the discordance rate between these recommendations. Methods: MTB discussions between April 1, 2021 and December 31, 2021, were retrospectively evaluated. MTBs which assessed NGS reports with or without significant genetic mutations but with drug recommendations were included. NGS testing was done with multiple vendors. Patients from all over India, Nepal, Bangladesh, Dubai and Abu Dhabi were discussed. We excluded MTBs which assessed NGS data without any drug recommendations. We compared therapeutic recommendations provided in the NGS report with the first-choice recommendation in the MTB discussion. Recommendation discordance was defined as disagreement between the NGS recommendation and the first MTB recommendation that either instructed its implementation either immediately or on disease progression. Results: 70 MTB data was studied. 49 MTBs assessing NGS reports of 49 unique patients (median age 54 years; range, 32-82) were included in the study. 13 patients had lung cancer, 10 colorectal, 6 breast, 7 hepatopancreatobiliary, 4 carcinoma of unknown primary and 9 others. 17 did not provide any treatment recommendations and hence were excluded. 4 were discussions based on NGS reports previously discussed in an MTB that was already included in the study, hence were excluded. Recommendation discordance rate was 49% (24 of 49). Conclusions: To our knowledge, this is the first study that assessed discordance rate in recommendations between NGS report and MTB from a low- and middle-income country setting. Accurate clinical translation of complex genomic data is at the forefront of personalized cancer care.