Genetic Testing for Cancer Risk: BRCA, Lynch, and Beyond

By Joe Barnett On 7 Jan, 2026 Comments (15)

When you hear the word genetic testing, you might think of ancestry kits or fun DNA reports. But for people with a strong family history of cancer, it’s something far more serious-and potentially life-saving. Testing for inherited mutations like BRCA1, BRCA2, and Lynch syndrome genes isn’t about curiosity. It’s about knowing your risk before cancer starts, and taking steps to stop it.

What BRCA and Lynch Really Mean

BRCA1 and BRCA2 aren’t just names. They’re genes that help fix damaged DNA. When they’re broken by an inherited mutation, your body loses a major defense against cancer. Women with a harmful BRCA1 mutation have up to a 72% chance of developing breast cancer by age 80. For BRCA2, it’s around 69%. Ovarian cancer risk jumps to 44% for BRCA1 and 17% for BRCA2. Compare that to the general population’s 13% lifetime breast cancer risk and less than 2% for ovarian cancer.

Lynch syndrome is different. It’s not about breast or ovarian cancer-it’s about colorectal, endometrial, stomach, and other cancers. It’s caused by mutations in MLH1, MSH2, MSH6, PMS2, or EPCAM. Someone with Lynch has a 10% to 80% lifetime risk of colorectal cancer, depending on which gene is affected. That’s not a small chance. It’s a ticking clock.

These aren’t rare. About 1 in 400 people carry a BRCA mutation. Lynch syndrome affects 1 in 280. Most people don’t know they have it until someone in the family gets cancer young-or multiple family members get different cancers. That’s why testing matters.

How Testing Works Today

Forget testing just one gene. The standard now is a multigene panel. These tests look at 30 to 80 genes linked to cancer risk all at once. You give a blood or saliva sample. Labs use next-generation sequencing to scan your DNA for mutations. Results come back in about two to three weeks.

Companies like Myriad and Invitae run these tests with near-perfect accuracy-99.8% sensitive, 99.9% specific. But here’s the catch: not every change in your DNA is clearly good or bad. Some are called variants of uncertain significance, or VUS. That means scientists don’t yet know if it increases cancer risk or not.

That used to be a huge problem. In 2023, about 12.7% of BRCA2 test results showed a VUS. In February 2025, Mayo Clinic researchers published a breakthrough study using CRISPR to test nearly 7,000 BRCA2 variants. They reclassified 91% of them-turning uncertainty into clarity. For the DNA-binding region of BRCA2, VUS rates dropped from 12.7% to just 1.1%. That’s a game-changer for thousands of people who got confusing results before.

Why Panels Beat Single-Gene Tests

You might think: “If I’m worried about breast cancer, why test for colon cancer genes?” Because cancer doesn’t care about your assumptions.

A 2023 study of over 38,000 people found that testing only BRCA1 and BRCA2 missed 30% to 50% of actionable mutations. People walked away thinking they were safe-when they actually carried a dangerous mutation in PALB2, ATM, or CHEK2. These genes are now part of the NCCN’s top-tier list of clinically useful genes as of 2025.

Single-gene tests have lower VUS rates (around 2.3%), but they’re blind to the bigger picture. Multigene panels, while increasing VUS rates to about 7.8%, find far more real threats. The trade-off is worth it. Finding a Lynch mutation in a 42-year-old with colon cancer led to immunotherapy with pembrolizumab-and complete remission, according to a 2025 Fred Hutchinson case study.

What Direct-to-Consumer Tests Don’t Tell You

23andMe offers a BRCA test. It sounds convenient. But it only checks for three specific mutations common in people of Ashkenazi Jewish descent. That’s it. For everyone else-97% of the population-it misses nearly every harmful BRCA variant. A 2024 NEJM study showed that 97% of pathogenic BRCA mutations in non-Ashkenazi individuals are invisible to these tests.

And it gets worse. These tests don’t include Lynch genes. They don’t cover PALB2, CHEK2, or ATM. You get a false sense of security. One woman in a 2025 Reddit thread shared that she tested negative on 23andMe, skipped medical screening, and was diagnosed with stage 3 ovarian cancer at 34. Her family had multiple cases. She never knew she was at risk.

Don’t use DTC tests for medical decisions. Ever.

A lab technician with a sequencer displaying glowing cancer risk genes and a discarded DTC test box.

Who Should Get Tested

Not everyone needs this. But if any of these apply to you, talk to your doctor:

You were diagnosed with breast cancer before age 50
You have ovarian, pancreatic, or metastatic prostate cancer at any age
Multiple close relatives have breast, ovarian, colorectal, or endometrial cancer
A family member tested positive for a hereditary cancer mutation
You’re of Ashkenazi Jewish descent and have any family history of breast, ovarian, or pancreatic cancer

The National Comprehensive Cancer Network (NCCN) guidelines are clear: if you meet these criteria, you should get a multigene panel test. Not a single-gene test. Not a DTC kit. A full panel, ordered through a medical provider.

The Critical Role of Genetic Counseling

Testing without counseling is dangerous. You could misunderstand your results. You might panic over a VUS. Or worse-you might ignore a positive result because you didn’t understand what it meant.

Before testing, you need a 60- to 90-minute session with a certified genetic counselor. They’ll map your family history, explain what each gene means, and help you weigh the emotional and medical consequences. After testing, they’ll interpret your results and help you decide on next steps: more frequent screenings, preventive surgeries, or targeted treatments.

Yet, only 87% of U.S. cancer centers meet this standard. In community clinics, it’s even lower. Many doctors still order tests without counseling. That’s a gap. And it’s putting lives at risk.

What Happens After a Positive Result

Finding a mutation isn’t a death sentence. It’s a heads-up.

For BRCA carriers:

Women can start breast MRI and mammograms at age 25
Prophylactic mastectomy reduces breast cancer risk by up to 95%
Removal of ovaries and fallopian tubes by age 35-40 cuts ovarian cancer risk by 80% and breast cancer risk by 50%

For Lynch syndrome carriers:

Colonoscopies every 1-2 years starting at age 20-25
Endometrial biopsies annually for women
Aspirin daily (shown to reduce colorectal cancer risk by up to 60% in Lynch patients)

And here’s the biggest win: if you have a mutation and get cancer, your treatment changes. PARP inhibitors like olaparib work wonders for BRCA-related breast and ovarian cancers. Immunotherapy works better for Lynch-related tumors. Genetic testing doesn’t just prevent cancer-it makes treatment more effective.

A family reviewing genetic reports with a holographic timeline of inherited cancer history.

The Hidden Costs and Risks

Medicare and most private insurers cover testing if you meet NCCN criteria. Approval rates are 98.7%. But out-of-pocket costs for self-pay patients can hit $450. And if you need a retest because your VUS got reclassified? Myriad charges $250 for that update. Some patients can’t afford it.

Then there’s insurance discrimination. GINA protects you from health insurance discrimination based on genetic results. But it doesn’t cover life, disability, or long-term care insurance. A 2024 survey found 9% of people who tested positive reported being denied coverage or charged higher premiums.

And VUS still cause anxiety. One in five people report significant stress after getting a VUS result-even when told it’s likely harmless. That’s why follow-up counseling matters.

What’s Next for Genetic Testing

The future is brighter. Stanford researchers identified 380 gene-regulating variants linked to cancer risk across 13 types. These aren’t single-gene mutations-they’re subtle switches that nudge your risk up or down. Soon, we’ll combine them into polygenic risk scores. Imagine knowing your cancer risk isn’t just from one broken gene, but from dozens of small genetic tweaks.

And the push is on to test everyone with cancer. A 2025 ASCO survey found 67% of oncologists support universal germline testing for all cancer patients. Why? Because finding a mutation doesn’t just help you-it helps your whole family. Cascade testing (testing relatives after a positive result) is the most cost-effective cancer prevention tool we have.

But it won’t work unless access improves. Black patients are tested at less than half the rate of white patients. Community clinics still lag behind academic centers. We need better training for doctors, better funding for counseling, and more equitable access.

Final Thoughts

Genetic testing for cancer risk isn’t about fear. It’s about power. The power to act before cancer starts. The power to choose prevention over treatment. The power to protect your children and siblings.

If you have a family history of cancer, don’t wait for a diagnosis to get tested. Talk to your doctor. Ask for a referral to a genetic counselor. Get a multigene panel. Don’t settle for a DTC test. Don’t skip counseling.

Knowing your genes doesn’t mean you’ll get cancer. It means you’ll know how to stop it.

Who should consider genetic testing for cancer risk?

Anyone with a personal or family history of early-onset cancer (before 50), multiple related cancers in close relatives, or known hereditary cancer mutations in the family. People of Ashkenazi Jewish descent with any family history of breast, ovarian, or pancreatic cancer should also consider testing. The NCCN guidelines outline specific criteria for who qualifies.

Can I just use a 23andMe or AncestryDNA test for cancer risk?

No. Direct-to-consumer tests like 23andMe only screen for three specific BRCA mutations common in Ashkenazi Jewish populations. They miss over 97% of harmful BRCA variants in other groups and don’t test for Lynch syndrome or other high-risk genes. These tests are not medically reliable and should never be used to make health decisions.

What if my test shows a variant of uncertain significance (VUS)?

A VUS means scientists don’t yet know if the gene change increases cancer risk. It’s not positive or negative. Most VUS are eventually reclassified as benign. Since early 2025, research from Mayo Clinic has drastically reduced VUS rates in BRCA genes-from over 12% down to under 1.5% in key regions. You should get follow-up counseling and consider retesting in 1-2 years as knowledge improves.

Does insurance cover genetic testing?

Yes, if you meet NCCN guidelines. Medicare covers testing with a 98.7% approval rate. Most private insurers do too. Out-of-pocket costs for self-pay patients range from $250 to $450. Some labs charge extra for reclassification updates. GINA protects against health insurance discrimination, but not life, disability, or long-term care insurance.

Will testing change my treatment if I already have cancer?

Absolutely. If you have a BRCA mutation and develop breast or ovarian cancer, you may benefit from PARP inhibitors like olaparib, which are more effective in these cases. If you have Lynch syndrome and colorectal cancer, immunotherapy drugs like pembrolizumab often work better. Testing can guide your treatment choices and improve outcomes.

Can I be denied insurance because of my genetic test results?

Under GINA, health insurers and employers cannot use your genetic test results to deny coverage or employment. However, GINA does not cover life insurance, disability insurance, or long-term care insurance. Some people have reported being denied or charged more for these types of policies after a positive result. It’s important to understand these limits before testing.