Breast Cancer on the Rise in Women Under 50: Rani Bansal, MD

In this interview with The American Journal of Managed Care^® (AJMC^®) Rani Bansal, MD, medical oncologist at Duke Cancer Center Breast Clinic, breaks down what may be driving the increase of breast cancer in women younger than age 50. Bansal explores the likely drivers behind the surge, from shifting reproductive patterns and rising obesity rates to chemical exposures that may be disrupting endocrine pathways. She also addresses whether the increase reflects a true biological change or improved detection and makes the case for risk-based screening in younger patients.

This transcript was lightly edited for clarity

AJMC: The 2025 report from the American Cancer Society revealed that for women under 50, the risk of developing cancer is 82% higher than men, which is up from 51% in 2002. When you look at this data on increasing cancer rates in women under 50 in particular, what stands out to you the most, and does it surprise you as a clinician?

Bansal: What worries us most is that we are seeing this difference in younger patients—those under the age of 50—especially compared with older patients. Usually, for decades, when we think about breast cancer, we think of it more as something we see in older patients, not younger patients. The incidence rate, after the most recent report, increased significantly in our younger patients which is different than what we were seeing decades ago. A lot of us are trying to understand why we are seeing that and what could be contributing, to see if there are things we can do to prevent these cases in our younger patients.

AJMC: Is there anything that has been found to cause that increase?

Bansal: It is tricky. There are a lot of data and many trials and studies looking into this, so we do not have anything concrete yet. Based on everything we are seeing, we think it is likely multifactorial, as many different things probably contribute. One thing that has changed a lot for women compared with decades ago is reproductive patterns and preferences. Years ago, women were having children at a younger age, having multiple children, and breastfeeding, potentially at a younger age and for longer. We do know that those factors, having children at an older age, having fewer children, and not breastfeeding are all associated with estrogenreceptor (ER)–positive breast cancer. A lot of the cases we are seeing an increase in are ER-positive breast cancer.

But I do not think that is the only thing. As a population, our diets have changed, and rates of obesity have risen over time, and there is an association between obesity and breast cancer. One thing that a lot of us are really concerned about, and that has been in the news, is chemical exposure. There is a lot of interesting data looking at whether some of these chemicals could be disrupting our endocrine pathways and whether that is why we are starting to see younger women with more endocrine-driven breast cancers due to exposures over time. There are really interesting data comparing women born in the 1950s vs the 1990s and how their risk differs based on birth year. That, to me, suggests there are likely multiple environmental and generational factors at play. Unfortunately, at this moment, there is not just one thing we could say that is definitively the cause. It is going to take time to look at all these different changes and really try to pinpoint whether there is something specific or whether it is truly a mix of everything.

AJMC: Do you think this is a true biological increase in cancer, or is it that detection is getting better and we are finding cancers that we might not have before?

Bansal: I think it is actually a biological change, and the reason I believe that is that our screening recommendations currently start at age 40. So yes, we have improved in detecting and potentially reducing mortality for patients between 40 and 50, because we are now screening at a younger age, but we are still seeing the rate increase in younger patients under 40, and we are not typically screening those patients. So, I think this is something biological that we need to take seriously.

AJMC: Are we screening young women early enough and broadly enough? What are your thoughts on risk-based screening as opposed to age-based screening?

Bansal: I definitely think there are benefits to risk-based screening, especially for our younger patients. There is a lot of data showing that we have made improvements in reducing breast cancer–related mortality with screening mammography, and I think the update to start at 40 is consistent with that. For patients under 40, I really do think a risk-based approach is needed. There are many factors that can increase a patient's lifetime risk for breast cancer such as family history, prior treatments, radiation exposure, and dense breast tissue. A lot of our guidelines and societies are recommending that at age 25 patients at least undergo a risk-based assessment of what their risk looks like. That could really help guide decisions about whether they meet criteria for earlier screening methods, whether that be earlier MRIs or being set up with a high-risk clinic.