Up to 10% of all cancers are caused by inherited genetic changes passed from parent to child. These aren’t random mutations that accumulate over a lifetime. They’re gene changes you’re born with that significantly raise your risk for specific cancer types. The most well-known hereditary cancers involve the breast, ovaries, colon, and uterus, but the full list is broader than most people realize.
Breast and Ovarian Cancer (BRCA1 and BRCA2)
Inherited changes in the BRCA1 and BRCA2 genes are the most widely recognized hereditary cancer risk. More than 60% of women who carry a harmful BRCA1 or BRCA2 change will develop breast cancer during their lifetime, compared to about 13% of women in the general population. The ovarian cancer risk is also dramatically elevated: 39% to 58% for BRCA1 carriers and 13% to 29% for BRCA2 carriers.
These genes don’t only affect women. Men with BRCA2 changes have a 19% to 61% chance of developing prostate cancer by age 80. Both BRCA1 and BRCA2 carriers also face an increased risk of pancreatic cancer, with up to 5% of BRCA1 carriers and 5% to 10% of BRCA2 carriers developing it over their lifetime. Male breast cancer, while rare overall, is another recognized risk.
Colorectal and Uterine Cancer (Lynch Syndrome)
Lynch syndrome is the most common cause of hereditary colorectal cancer. People with this condition carry changes in genes responsible for repairing DNA copying errors. When those repair genes don’t work properly, cancer-driving mutations accumulate much faster than normal.
The numbers are striking: individuals with Lynch syndrome have a 60% to 80% lifetime risk of colorectal cancer. For women, endometrial (uterine) cancer is the second most common Lynch-associated cancer, with a 40% to 60% lifetime risk. Women also face a 10% to 12% lifetime risk of ovarian cancer. Beyond these, Lynch syndrome raises the risk of cancers in the stomach, small intestine, urinary tract, biliary tract, and brain. Brain tumors are actually the third leading cause of cancer death among people with Lynch syndrome.
A related condition, familial adenomatous polyposis (FAP), is caused by a change in a different gene. People with FAP develop hundreds to thousands of polyps in the colon, and without intervention, colorectal cancer is nearly inevitable.
Li-Fraumeni Syndrome
Li-Fraumeni syndrome involves an inherited change in the TP53 gene, often called the “guardian of the genome” because it normally prevents damaged cells from multiplying. When this gene doesn’t function correctly, the cancer risk is exceptionally broad. The most common cancers include breast cancer, soft tissue sarcomas, bone cancers, brain tumors, and adrenal gland cancers. These cancers often appear at unusually young ages, sometimes in childhood, and a person may develop multiple different cancers over their lifetime.
Thyroid, Breast, and Endometrial Cancer (Cowden Syndrome)
Cowden syndrome results from changes in the PTEN gene, which normally acts as a brake on cell growth. Without that brake, people develop a high risk of thyroid cancer (particularly follicular thyroid cancer), breast cancer, and endometrial cancer. Colon cancer and kidney cancer are also associated with this syndrome, though at lower rates. Cowden syndrome often comes with noncancerous features too, like skin growths and an unusually large head circumference, which can be early clues for diagnosis.
Kidney Cancer and Other Rarer Syndromes
Von Hippel-Lindau syndrome, caused by changes in the VHL gene, predisposes people to kidney cancer, along with tumors in the brain, spinal cord, eyes, adrenal glands, and inner ear. Another condition called hereditary leiomyomatosis and renal cell cancer syndrome also raises kidney cancer risk, along with noncancerous skin and uterine growths.
Multiple endocrine neoplasia type 2 (MEN2) involves changes in the RET gene and primarily causes medullary thyroid cancer, along with tumors of the adrenal and parathyroid glands. Hereditary diffuse gastric cancer syndrome, linked to changes in the CDH1 gene, significantly raises the risk of a particularly aggressive form of stomach cancer and also increases breast cancer risk in women.
Signs Your Family History May Point to Hereditary Cancer
Most cancers are not hereditary. The 90% or more that arise from non-inherited causes develop through a combination of aging, environmental exposures, and random DNA errors. But certain patterns in a family suggest something inherited may be at work:
- Young age at diagnosis: cancer appearing before age 50, especially breast, colorectal, or uterine cancer
- Multiple relatives with the same cancer: particularly on the same side of the family (all on your mother’s side or all on your father’s side)
- Multiple different cancers in one person: such as someone who had both breast and ovarian cancer
- Rare cancer types: male breast cancer, for example, is a strong indicator
- Cancer in paired organs: both breasts or both kidneys
- Related cancers clustering together: colon cancer and uterine cancer in the same family (both linked to Lynch syndrome), or breast and ovarian cancer together (both linked to BRCA changes)
The more of these patterns you see, the stronger the case for a hereditary syndrome.
Who Should Consider Genetic Testing
Clinical guidelines recommend genetic testing for anyone diagnosed with triple-negative breast cancer, ovarian cancer, pancreatic cancer, colorectal cancer before age 50, metastatic prostate cancer, or male breast cancer. For these cancers, knowing whether an inherited gene change is involved can directly influence treatment decisions.
If you haven’t been diagnosed with cancer but your family history raises red flags, genetic counseling is the typical starting point. A genetic counselor can map your family history, assess whether testing makes sense, and explain what results would actually mean for you. When possible, testing usually starts with a family member who has already had cancer, since a positive result in that person confirms a specific gene change that other relatives can then be tested for. A negative result in someone who never had cancer is harder to interpret, because it could simply mean the family’s cancer risk comes from a gene that wasn’t included in the test panel.
Identifying a hereditary cancer syndrome doesn’t mean cancer is certain. It means you and your doctors can build a screening and prevention plan calibrated to your actual risk level, catching problems earlier or in some cases preventing them entirely.