Nearly one in four Indian breast cancer patients carry an inherited genetic risk for the disease, according to a new study from the Indian Institute of Technology (IIT) Madras. This research, one of the largest of its kind in India, found that most of these inherited risks lie outside the well-known BRCA1 and BRCA2 genes.
Study Details and Findings
The study analyzed DNA samples from 479 breast cancer patients. These samples were sourced from the National Cancer Tissue Biobank at IIT Madras. The research was a collaboration between IIT Madras and Karkinos Healthcare. It was conducted with partners Kumaran Hospital and Chennai Breast Centre. The findings were published in the journal ‘BMC Cancer’.
The data revealed that 24.6% of patients had at least one inherited genetic variant linked to cancer. Specifically, 8.35% had mutations in BRCA1 or BRCA2. A larger group, 11.9% , carried inherited variants in other genes. These genes are involved in DNA repair processes. Overall, 67% of these identified risks were in genes other than BRCA.
Key Genes Identified
The study highlighted variants in several non-BRCA genes. These include MLH1 , NF1 , TP53 , and RB1 . This finding suggests that testing only for BRCA mutations may miss many inherited cancer risks.
Call for Wider Genetic Testing
IIT Madras researchers emphasized the need to update India’s genetic testing strategies. Current approaches often focus narrowly on BRCA genes or specific gene regions. The study provides a detailed genetic profile for Indian breast cancer patients. This information can aid in developing personalized cancer treatments and family-based risk reduction plans.
Lead author S Mahalingam of IIT Madras stated that the findings have direct implications for clinical practice. He called for broader multi-gene panel or exome-based genetic testing in India. The researchers also stressed the importance of building India- and South Asia-specific genetic databases. Accurate risk assessment depends on these specialized resources.
Additional Health Risks Found
Beyond cancer predisposition, the study identified actionable variants in over 21% of patients. These variants were linked to other health conditions. These include inherited heart disorders and metabolic diseases. Furthermore, the analysis found DPYD variants. These variants are associated with increased toxicity from chemotherapy. Routine genetic screening before treatment is recommended to identify these risks.
The study concluded that personalized cancer care tailored to India’s population is crucial. Developing genomic policies specific to India’s population structure and disease burden is essential. This approach can improve cancer care outcomes across the country.