Is Cancer Genetic and Will My Children Get It?

Only 5% to 10% of cancers come from inherited gene mutations passed parent to child. The rest develop from mutations picked up through lifestyle, environment, and chance over a lifetime. Carrying BRCA1 or BRCA2 raises risk significantly but doesn’t guarantee cancer. A child who inherits a cancer-linked mutation has an elevated risk that can be managed through testing, surveillance, and preventive steps. Not a certainty.

According to Dr. Sandeep Nayak, Best cancer treatment in Bangalore, “Most patients who come in worried their children will get cancer are carrying a sporadic mutation, not a hereditary one. That distinction matters. Genetic testing tells you which category you’re in and what your family actually needs to do differently.”

Not every cancer type carries the same hereditary risk. Some follow clear genetic patterns. Others rarely run in families at all.

• Breast and Ovarian Cancer: BRCA1 and BRCA2 mutations take lifetime breast cancer risk from 13% in the general population up to 50% to 72%. A parent with a confirmed BRCA mutation gives each child a 50% chance of carrying it too.
• Colon Cancer: Lynch syndrome puts lifetime colon cancer risk at up to 80% and sits behind roughly 3% of all colorectal diagnoses. Familial adenomatous polyposis is different. It produces hundreds of colon polyps by age 30 that turn malignant if nobody acts on them.
• Thyroid Cancer: About 25% of medullary thyroid cancers are hereditary through RET gene mutations. The common differentiated thyroid cancers are mostly sporadic. Same organ, very different inheritance story.
• Pancreatic Cancer: BRCA2 mutations raise pancreatic cancer risk 3 to 6 times above baseline. Relatives of pancreatic cancer patients with a known germline mutation qualify for surveillance imaging from age 50, or 10 years before the youngest family diagnosis, whichever comes first.

Genetic Counselling maps the family history, works out which mutations are worth testing, and tells each person what their individual risk actually looks like based on what the genes show.

Having a parent with cancer doesn’t mean children need testing. But some situations change that.

• When Testing Makes Sense: Two or more close relatives with the same cancer, a diagnosis before 50, bilateral cancer in a paired organ, or a confirmed mutation already in the family. Any of these patterns points toward hereditary syndrome.
• What Testing Involves: Blood or saliva. Results in 2 to 4 weeks. A positive result isn’t a cancer diagnosis. It’s a risk level with a surveillance plan matched to that specific mutation and how strongly it expresses.
• Risk Reduction Options: BRCA-positive women can go with enhanced imaging, chemoprevention, or risk-reducing surgery. Lynch syndrome carriers get colonoscopy every one to two years. Hereditary Breast cancer management follows protocols built around the mutation type, not a generic cancer plan.
• When Not to Test: Children under 18 aren’t tested for adult-onset hereditary syndromes. Results can’t change clinical care until adulthood, so testing waits until they can make that call independently.

For more on how late detection compounds risk in high-risk individuals, our previous blog on Cancer Left Untreated covers why timing changes outcomes so sharply.

Dr. Sandeep Nayak’s team at MACS Clinic offers genetic counselling for families with hereditary cancer syndromes, including BRCA testing, Lynch syndrome workup, and cascade testing for close relatives of confirmed mutation carriers. Testing is matched to family history and clinical pattern, not ordered as a formality.

Family members of patients diagnosed here don’t leave without knowing whether their risk is sporadic or hereditary. Because that answer changes what screening they need, when they need it, and whether acting now is worth it.

Call +91 8035740000 to book your consultation.

References

1. Hereditary cancer syndromes — National Cancer Institute
2. Genetic testing for cancer risk — World Health Organization