Abstract
For the young breast cancer population in India, the burden of hereditary breast cancer is not well defined. Moreover, genetic testing criteria (National Comprehensive Cancer Network and Mainstreaming Cancer Genetics (MCG) plus) have never been validated for the Indian population. Therefore, this study tested 236 consecutive breast cancer patients for germline pathogenic mutations using next-generation sequencing and reflex Multiplex Ligation Probe Amplification (MLPA). The findings showed a high prevalence of pathogenic/likely pathogenic (P/LP) mutations (18.64%), with 34% mutations in non BRCA genes. The sensitivity of the testing criteria was inadequate (88.6% for NCCN and 86.36% for MCG plus criteria), reiterating the need to expand the criteria. The uptake of cascade testing was low (10% of eligible previvors), highlighting this as an area of unmet need. Multicentric studies to validate these data and provide further insight into the hereditary cancer burden in India are the need of the hour.