Hereditary cancer risk is both more common and more actionable than often assumed
In the small Baltic nation of Estonia, a decade-long study of over three thousand people has quietly redrawn the map of hereditary cancer risk. Nearly one in five relatives of breast and ovarian cancer patients were found to carry dangerous genetic variants — and among men, the rate climbed to one in three. The findings arrive as a quiet argument against waiting: most carriers were identified a full decade before standard screening age, and the youngest tested showed the highest rates of risk, suggesting that the window for prevention opens far earlier than medicine has traditionally looked.
- A study of 3,472 Estonians found that 19.7% of cancer patients' relatives carry pathogenic BRCA1 or BRCA2 variants — a rate far higher than most people or health systems anticipate.
- Men are being left behind: one in three male relatives tested positive, yet men are rarely referred for genetic screening, leaving a significant population of carriers undetected and unprotected.
- The average carrier identified was 41 years old — a decade younger than Estonia's standard screening threshold of 51 — meaning current protocols are systematically missing years of preventive opportunity.
- Even among relatives with no known family variant on record, 8% still tested positive, dismantling the assumption that a clean family history means a clear genetic slate.
- Researchers are pushing for broader multigene panel testing, earlier referrals, and deliberate strategies to bring men into genetic counseling before cancers that could have been prevented have a chance to develop.
When Angelina Jolie disclosed her BRCA1 mutation in 2013 and chose preventive surgery, she brought hereditary cancer risk into public consciousness. But the question of how common such risk actually is among ordinary families — and how early it can be found — has taken years of careful research to begin answering.
A team led by Dr. Mikk Tooming at the Institute of Clinical Medicine in Tartu reviewed genetic testing records from 3,472 Estonians tested between 2007 and 2023, most referred after a family member was diagnosed with breast or ovarian cancer. The result was striking: nearly one in five carried a pathogenic variant substantially elevating their cancer risk. Among men, the proportion rose to one in three.
What gave the findings particular urgency was the age profile of those testing positive. Carriers averaged 41 years old — a full decade younger than Estonia's standard screening age of 51 — and those under 30 showed the highest detection rates of all. The implication is uncomfortable: by waiting for people to reach conventional screening thresholds, health systems are forfeiting years in which intervention is still possible.
The study also exposed a blind spot around male relatives. Among men with no known family variant, a third still tested positive — suggesting that male carriers are routinely missed simply because no one thinks to test them. Men carrying BRCA2 variants face elevated risks for prostate and other cancers, risks that often go unrecognized until it is too late for prevention.
Tooming was careful to frame early identification not as a mandate but as an opening. Knowing one carries a pathogenic variant allows for enhanced surveillance, earlier imaging, and in some cases a conversation about preventive surgery — decisions that are deeply personal and must be made within the context of genetic counseling. The researchers advocate for broader multigene panel testing, systematic outreach to relatives of affected patients, and deliberate efforts to include men in genetic screening programs. The core message, they argue, applies well beyond Estonia: hereditary cancer risk is more common than assumed, and more actionable — but only if we look early enough to act.
In 2013, Angelina Jolie announced she carried a dangerous variant of the BRCA1 gene and chose to have her breasts removed before cancer could develop. The revelation sparked global interest in genetic testing. But knowing whether you carry such a variant matters far beyond celebrity cases—it can reshape how someone approaches their own health, what screenings they pursue, and whether preventive surgery becomes a reasonable choice.
Researchers in Estonia wanted to understand how common these cancer-risk genes actually are among people whose relatives have already been diagnosed. They reviewed genetic testing results from 3,472 individuals tested between 2007 and 2023, most of them referred because a family member had breast or ovarian cancer. What they found was striking: nearly one in five carried a pathogenic variant—a genetic mutation that substantially elevates cancer risk. Among the men tested, the rate climbed to one in three.
The study, led by Dr. Mikk Tooming of the Institute of Clinical Medicine in Tartu, revealed something else that caught researchers' attention. The people who tested positive were, on average, 41 years old—a full decade younger than Estonia's standard cancer screening age of 51. More than three-quarters of those tested were younger still. And those under 30 showed the highest rates of carrying dangerous variants. This matters because it suggests that waiting until someone reaches typical screening age to check for genetic risk means missing years of opportunity to intervene.
Of the 3,472 people tested, 87.6 percent were women and 12.4 percent were men. The researchers identified 23 different pathogenic variants across the group, but nearly 60 percent of all cases involved just two genes: BRCA1 and BRCA2. Among people who had a known family member already carrying a variant, 41.8 percent tested positive themselves. But here's what surprised the researchers: among those with no known familial variant in their family history, 8 percent still carried one. And among men without a known family variant, a third tested positive—suggesting that many male carriers go undetected simply because no one thought to test them.
Tooming emphasized that early identification opens doors. Once someone knows they carry a pathogenic variant, they can pursue enhanced surveillance—more frequent breast imaging, for instance, or earlier screening. In some cases, people might consider preventive surgery. But these are deeply personal decisions that require genetic counseling, not blanket recommendations. "Such decisions are highly individual and should always be made in the context of genetic counseling, taking into account personal risk, age and preferences," Tooming said.
The study also revealed a methodological wrinkle worth noting. In 2007, only three people underwent testing in Estonia. By 2023, that number had grown to 731. More significantly, the introduction of next-generation sequencing after 2015 made detection more reliable and comprehensive. This means the study likely underestimated how many carriers existed in earlier years—people whose variants would be caught today but were missed then.
Tooming and his colleagues argue that the findings should reshape how countries approach genetic risk. Rather than simply lowering the age at which standard cancer screening begins, they suggest broader and more systematic genetic testing among relatives of affected patients. They also advocate for wider access to multigene panel testing, which can identify carriers of multiple different variants at once. And they call for strategies to increase male participation in genetic testing, since men face elevated risks for prostate cancer and other malignancies if they carry BRCA2 variants—risks that often go unrecognized.
The implications extend beyond Estonia. The researchers note that more work is needed to understand how common these variants are in other populations, and to better understand the biological and clinical impact of less common or moderate-risk variants. But the core message is clear: hereditary cancer risk is far more common than many people assume, and far more actionable. Waiting for symptoms to appear, or for someone to reach standard screening age, means leaving years of preventive opportunity on the table.
Citas Notables
Hereditary cancer risk is both more common and more actionable than often assumed. People with a family history of breast or ovarian cancer should strongly consider genetic counseling and, where appropriate, genetic testing.— Dr. Mikk Tooming, Institute of Clinical Medicine, Tartu
Early identification of carriers allows individuals to access tailored risk management strategies, including enhanced surveillance and, in some cases, consideration of risk-reducing options.— Dr. Mikk Tooming
La Conversación del Hearth Otra perspectiva de la historia
Why does it matter that people are tested at 41 instead of 51? Isn't earlier screening always better?
The difference is that genetic testing isn't screening—it's risk assessment. If you know at 41 that you carry BRCA1, you can start enhanced surveillance immediately, or consider preventive surgery while you're still healthy. If you wait until 51, you've lost a decade of options. For someone under 30, that gap is even more consequential.
But the study found that 78.6 percent of people tested were younger than the mean age of 41. That's a lot of very young people. Why would they be getting tested at all?
Because they had a family history. Their mother or aunt or grandmother had breast cancer, and doctors suspected a hereditary link. These young people were referred specifically because of that family pattern. The point is, they're the ones most likely to carry the variant—and they're young enough that early intervention could prevent cancer entirely.
What about the men? The study says a third of men without a known family variant still tested positive. How does that happen?
Most men don't get tested unless there's already a known variant in the family. But if you test them anyway, you find carriers. They just weren't on anyone's radar. That's the blind spot—men often don't think of themselves as at risk for hereditary breast cancer, and doctors don't always think to test them. But BRCA2 carriers face real prostate cancer risk.
Is preventive surgery the only option for someone who tests positive?
No. Surgery is one tool, and it's not right for everyone. Enhanced surveillance—more frequent imaging, earlier screening—is another path. Genetic counseling helps people weigh their personal risk, their age, their preferences. The point is that knowing you carry the variant gives you options at all. Without that knowledge, you're just hoping you don't develop cancer.
The study mentions that detection improved after 2015 when next-generation sequencing became available. Does that mean the 19.7 percent figure might be an underestimate?
Almost certainly. The researchers tested only three people in 2007. By 2023, it was 731. And the better technology caught more variants. So people tested in the early years of the study probably had variants that went undetected. The true prevalence in those families might have been higher all along.
What's the next step? What do researchers want to see happen?
Broader access to genetic testing, not just for people with a strong family history. Population-based screening that casts a wider net. Better strategies to get men tested. And more research into less common variants, to understand which ones truly matter clinically. Right now, the focus is on BRCA1 and BRCA2, but there are 23 variants in this study alone.