FoundationOne as a relevant tool for comprehensive genomic profiling and assessment of tumor mutation burden in the era of precision oncology in India.

Abstract

e23096 Background: Comprehensive genomic profiling (CGP) is gaining acceptability globally, but clinical experience in developing countries like India is limited. CGP identifies genomic alterations (GA), with tumor mutation burden (TMB) and microsatellite status (MSI), revealing therapeutic options such as targeted inhibitors and immunotherapies. We sought to evaluate the mutation frequency and actionability across tumors. Methods: Metastatic and/or refractory patients (referred to Personalized Cancer Medicine Clinic) underwent CGP analysis, including calculation of TMB and MSI, using a targeted NGS panel (FoundationOne, 53 samples; FoundationOne Heme, 4 samples). This panel detects all relevant classes of GA: base substitutions, small indels, rearrangements and copy number changes. Mutation frequencies were compared with the larger Foundation database. TMB status was reported as low (≤5 mutations/Mb), intermediate (6-19 mut/Mb) or high (≥20 mut/Mb). Results: The most common tumor types were lung (23%), breast (14%) and sarcoma (12%); other tumor types, including unknown primary constituted the rest (51%). Most samples were from metastatic sites (60%). Oncogenic GA were found in 131 genes across all tumor subtypes and affected major pathways: apoptosis/cell cycle (31%), PI3K (14%), transcriptional regulation (13%), and receptor tyrosine kinases (10%). Among these GA, 38 were considered actionable and were distributed across 43 (75%) samples. Therapies with FDA approval for the tumor type analyzed were indicated for 18 samples; an additional 25 samples had GA associated with therapies FDA approved for another indication. More than 1 actionable GA was identified in 24/43 (56%). TMB status was low in 36 (63%), intermediate in 19 (33%) and high in 2 (3.5%). High TMB status correlated with high MSI status (p < 0.001). Trend observed in the mutation frequency was comparable with the larger Foundation database. Conclusions: This is the first study in India showing CGP identified actionable targets associated with FDA approved therapies in approx. 32% of cases. TMB status identified 2/57 samples with high mutation burden for whom immunotherapy might be relevant.