Systematic Review of the Prevalence of BRCA1/2 mutation in Indian Breast Cancer Patients.

Collaborating Partners

Dr. Rahul Mhaskar

University of South Florida

URL: https://health.usf.edu/medicine/mdprogram/offices/rise

 

Dr. Santosh Dixit, Ashwini Bapat, Siddharth Gahlaut

Centre for Translational Cancer Research (CTCR); a joint initiative between Indian Institute of Science Education and Research and Prashanti Cancer Care Mission, Pune

URL : www.ctcr.in

 

Breast cancer (BC) is the most common cancer in India with approximately 164,000 cases BC diagnosed in India every year predominantly in middle-aged, urban women. The BC incidence-to-mortality ratio is highest in the world possibly attributed to late-stage disease presentation, inadequate medical facilities, lack of awareness about disease symptoms, and absence of screening programs. Indian patients have a higher prevalence of Triple Negative Breast Cancers (TNBCs), an aggressive clinical subtype with the highest fatality.

 

Globally, 10-12% of BC cases exhibit familial history or inheritance patterns suggestive of Hereditary Breast and Ovarian Cancer (HBOC) syndrome.  TNBCs appear to have a higher percentage of HBOC prevalence, mainly mediated by germline mutations in BRCA1/2 genes.  In India, as recommended by NCCN/ACMG guidelines, HBOC testing with multi-gene panels is becoming mainstream in India. HBOC genetic testing has clinical implications in BC radiodiagnosis, surgery, chemotherapy as well as risk assessment in affected families. Several research groups in India, including CTCR, are studying BRCA1/2 prevalence in Indian populations.

The CTCR group has established well-curated BC patient cohorts with clinicopathologic and BRCA1/2 genotype information. Translational research projects are underway to investigate the impact of BRCA1/2 mutations on pathology, radiological, surgical, and chemotherapy decision making with the help of human bio-specimens ( blood, cancer tissues) as well as in vitro/in vivo experimental model systems. In this effort, the CTCR team routinely performs data-mining from global BRCA1/2 consortia such as ENIGMA, CIMA, BIC, BRCAExchange, and TCGA.

In collaboration and guidance of Dr. Mhaskar, CTCR has undertaken a systematic literature review to determine the prevalence of BRCA1/2 mutations in Indian BC patients. In this effort, 60 relevant published studies have been collated from PubMed, Google Scholar, EMBASE, Web-of-Science, and ResearchGate. To determine the quality of these reports, a novel quality matrix has been developed based on key laboratory parameters as per ACMG guidelines.  It is anticipated that this quality-assessment tool will be useful for future researchers as well as laboratories that aim to embark on HBOC genetic testing.