Women diagnosed with abnormal breast cells at an early stage face a brutal unknown: will these cells stay contained or become invasive cancer? A new study suggests genetic analysis of hundreds of common variants can help answer that question for many cases of ductal carcinoma in situ and lobular carcinoma in situ. This could change how doctors balance aggressive treatment against watchful waiting.
What the study found
Researchers followed more than 2,000 women in the United Kingdom diagnosed with stage 0 breast lesions to track who later developed invasive disease. DNA from those women was analyzed across 313 common genetic variants and combined into a single genetic risk score. Women with higher scores were more likely to develop invasive breast cancer later, and that link held up regardless of age or the type of treatment they initially received.
Those results challenge the long-standing microscope-first approach to treatment selection. “Until now, treatment decisions have mostly been based on how these cells look under a microscope,” says Timbres. “We also need to consider a woman’s genetic risk, family history , and lifestyle factors. By looking at the full picture, we can give women more accurate information about their personal risk of recurrence. This will help them make more informed choices about their treatment options and what’s right for them,” says Timbres.
The idea is simple: add genetic context to what pathologists already see. Doing that could mean fewer unnecessary surgeries, radiation sessions, or hormonal treatments for women whose risk is low. It could also mean targeted prevention for those at higher genetic risk.
What this could mean in practice
Experts see a real possibility that a validated genetic score could guide surveillance and preventive treatment decisions. “The findings could be very useful for both the clinical community and patients. Currently, we do not have a reliable system to predict which women with DCIS or LCIS will go on to develop invasive cancer,” says Arya Roy, MD , a breast medical oncologist with the Ohio State University Comprehensive Cancer Center in Columbus.
That expert view is echoed in follow-up commentary about personalized care. “It highlights the potential for genetic risk scores to guide more personalized care in this setting,” she says. If confirmed, the score might be used to recommend closer imaging or preventive medications like tamoxifen or aromatase inhibitors for women identified as high risk.
Conversely, women with low genetic risk might safely avoid treatments that carry side effects without clear benefit. “At the same time, women found to be at lower risk might be able to avoid unnecessary treatments and the side effects that come with them. The risk score has the potential to improve outcomes for high-risk patients while reducing overtreatment and optimizing healthcare resources for those at lower risk,” she says.
That outcome — better matching of treatment to actual risk — is the core appeal of the research. But researchers and clinicians caution this is a first step rather than a final rule for care. The study’s retrospective nature means it shows correlation rather than proven clinical benefit from using the test in real time.
“It’s hard to know whether it could influence treatment outcomes, since this is a retrospective study and not based on prospective information,” says Dr. Chen, who wasn’t involved in the new research. Retrospective studies analyze existing records and can point to associations, but they cannot prove that acting on the genetic information would change outcomes for patients.
There are other limitations that temper enthusiasm and demand more work. The study population was almost entirely white and included far more women with DCIS than LCIS, so broader validation is needed across races and in larger LCIS samples. Researchers will also want prospective trials that test whether using the score to guide care actually reduces overtreatment or improves survival and quality of life.
Until those steps are taken, the score should not be used as the sole basis for major treatment decisions. Still, the research adds a useful tool to the conversation and gives clinicians a clearer sense of where genetics might fit into decision making for early breast lesions. It also emphasizes that risk is multi-factorial: genetics, family history, biology, and lifestyle all play a role.
For patients wondering whether to pursue genetic testing, clinical guidance is nuanced and personal. “Genetic testing may provide useful information, but the decision is personalized and should be made together with a healthcare team,” she says. Testing tends to be most informative for women with a strong family history of breast or ovarian cancer, younger age at diagnosis, or other signs that inherited cancer genes might be present.
Genetic counselors can help interpret results and weigh the pros and cons of testing, including what outcomes might change if a high risk is found. Results could affect screening intensity, preventive medication choices, and sometimes surgical decisions for those with marked inherited risk. The bottom line: this genetic risk score is promising, but it needs prospective validation before becoming a routine part of clinical care.
