For women diagnosed with abnormal breast changes at an early stage, a new study suggests genetic analysis may help answer a crucial question: Will these cells progress to invasive breast cancer?
DCIS and LCIS are abnormal cells confined to the milk ducts or lobules (milk-producing glands in the breast ducts).
Predicting which women with DCIS or LCIS are most likely to develop invasive breast cancer is vital to providing the best possible treatment options, because not all cases of stage 0 breast cancer proceed that way, says the first author, Jasmine Timbres, a clinical information analyst at King’s College in London.
Because it’s currently impossible to know which women will eventually develop invasive breast cancer, many undergo treatments they may not need, according to the study authors, including surgery, radiation, or hormone therapy.
The researchers behind the new study hope a genetic test to identify those most at risk will eventually pave the way toward more personalized treatment decisions.
Genetic Risk Score Helped Predict the Trajectory of DCIS and LCIS
The study followed more than 2,000 women in the United Kingdom who had been diagnosed with preinvasive stage 0 breast cancers. About 90 percent had DCIS, and the rest had LCIS.
The researchers used DNA analysis to scrutinize these cancers for 313 common genetic variants, combining the results into what’s called a genetic risk score.
Women with higher scores were more likely to develop invasive breast cancer later on. Importantly, the genetic score predicted risk regardless of other factors such as age or treatment type.
“Until now, treatment decisions have mostly been based on how these cells look under a microscope,” says Timbres. But these findings suggest that predicting which women are more likely to develop invasive breast cancer shouldn’t just rely on those methods, she says.
“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.
A Step Toward More Personalized Care
The risk score may identify those at higher risk of developing further breast cancers, whether in the same breast or the opposite breast, says Dr. Roy, who wasn’t involved in the research. “It highlights the potential for genetic risk scores to guide more personalized care in this setting,” she says.
What would that look like in practice? If the findings are confirmed, the risk score could help doctors tailor recommendations for surveillance intensity and risk-reduction strategies, including medications like tamoxifen or aromatase inhibitors, specifically for those high-risk women, says Roy.
“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.
The Study Has Some Limitations
May Chen, MD, a medical oncologist at Stanford Medicine in California, says the study is promising, but its findings shouldn’t be used to drive treatment decisions for patients, at least not yet.
She says it’s possible the genetic risk score could help determine risk level for women with stage 0 breast cancer, and potentially be used to guide women who would not otherwise consider treatment for their DCIS or LCIS lesions.
“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. In other words, the current study looked backward in time at existing patient records, instead of following people over time to see what happened.
That means the results can show a possible link, but they can’t prove that using the genetic test would change treatment decisions or improve cancer outcomes.
These findings need to be validated in further studies and with a bigger sample size, especially in women with LCIS, says Chen.
Future studies need to include women of different races and ethnicities to see if the findings would apply more broadly — the British and European population in this study were almost completely white women, she notes.
Should Women With Stage 0 Breast Cancer Ask for Genetic Testing?
If a woman has been diagnosed with preinvasive breast cancer, genetic testing can sometimes give more information about the risk of developing invasive breast cancer in the future, says Roy.
“Genetic testing may provide useful information, but the decision is personalized and should be made together with a healthcare team,” she says.
If a woman with stage 0 breast cancer is considering genetic testing, Roy offers the following considerations:
- Genetic testing can look for inherited gene changes (like BRCA1, BRCA2, or other gene variants) that may increase breast cancer risk.
- Knowing the results can help guide screening decisions, preventive measures, or treatment options.
- Not every woman with DCIS or LCIS needs genetic testing. It’s most helpful for those with a strong family history of breast or ovarian cancer, younger age at diagnosis, or other risk factors.
- A genetic counselor can review personal and family history, explain the pros and cons of testing, and help interpret the results.
