Daijiworld Media Network – New Delhi

New Delhi, Sep 16: When asked if cancer is a genetic disease, the answer is nuanced. Cancer is indeed driven by genetic changes in cells, but the vast majority of these changes are acquired, not inherited. Only a small fraction of cancers result from inherited mutations in high-risk genes such as BRCA1/2 or TP53.

At the cellular level, cancer arises when mutations in DNA allow cells to grow uncontrollably. Most of these somatic mutations accumulate over a person’s lifetime due to ageing, DNA replication errors, infections, or exposure to carcinogens like tobacco, UV radiation, chemicals, and air pollution. A smaller proportion of cancers, around 5–10%, are hereditary and linked to high-penetrance gene mutations, often prompting early surveillance or preventive interventions.

Modern research highlights the interaction between genes and environment. Lifestyle and environmental factors—including tobacco use, pollution, infections, diet, and physical inactivity—are the dominant determinants of cancer risk. For India, where tobacco use, indoor and outdoor air pollution, and infections like HPV and hepatitis B are prevalent, public health measures targeting exposures remain the most effective prevention strategy.

Tumour genetic profiling has revolutionised treatment, guiding targeted therapies, predicting prognosis, and identifying patients eligible for immunotherapy. Detecting germline mutations during tumour testing can also inform familial risk and trigger counselling.
Recent Indian studies show rising cancer incidence due to ageing, urbanisation, and lifestyle changes. Integrated public health efforts—tobacco control, vaccination, early detection programmes, and genetic counselling—are being prioritised.

Key takeaways for India:

• Families with early-onset or multiple related cancers should consider genetic counselling and testing.
• For the general population, prevention through lifestyle modifications, vaccination, pollution reduction, and regular screening is crucial.
• Patients with cancer should discuss tumour genetic testing with their oncologist to explore targeted treatment options and evaluate hereditary risk if indicated.

In short, cancer is a genetic disease of cells, but most mutations are acquired over a lifetime. Combining genomics-driven care with population-level prevention is the most pragmatic approach for India, empowering individuals while reducing the overall cancer burden.