Study shows more aggressive breast cancer than expected for younger women

New study has researchers urging women under 40 to be more proactive in monitoring breast changes as risk shown for this age group may be higher than guidelines suggest.

CANCER DIGEST – Dec. 6, 2025 – Women under 50 are being diagnosed with breast cancer more often than screening guidelines predict, with a large percentage of these cancers being invasive and harder to treat, according to new research presented at the Radiological Society of North America (RSNA) annual meeting being held in Chicago Nov. 29 - Dec. 3.

The findings challenge current age-based screening guidelines and underscore the need for earlier, individualized risk assessment for younger patients.

Researchers from Elizabeth Wende Breast Care Center in New York analyzed over 11 years of data from seven outpatient centers, reviewing 1,799 breast cancer diagnoses in women aged 18 to 49, with an average age at diagnosis of 42.6 years.

The study revealed that this age group consistently represented 20 percent to 24 percent of all breast cancer cases diagnosed annually, despite making up a slightly smaller share of those screened. A majority of the detected cancers were invasive (80.7%) and often aggressive, including triple-negative types which do not respond to common hormone therapies.

"This research shows that a significant proportion of (breast) cancers are diagnosed in women under 40, a group for whom there are no screening guidelines at this time,"  Dr. Stamatia Destounis, a radiologist involved in the study, said in a press release. "Women under 50, especially those under 40, shouldn't be seen as 'low risk' by default." 

National data have shown an upward trend in breast cancer among younger women, which has stirred concern among radiologists about the need for a re-evaluation of screening guidelines. 

Current U.S. guidelines generally recommend mammograms starting at age 40 or 45 for average-risk women, leaving a gap for those younger than 40. The study authors argue that all women in this younger demographic should receive risk assessments as early as possible to identify those who might benefit from more intensive screening due to higher risk.

Dr. Destounis for her part is urging physicians to encourage greater awareness among their younger patients and to pay more attention to breast changes, and for physicians to consider tailored screening approaches.

Source: Radiological Society of North America – "Doctors are seeing more aggressive breast cancer in younger women than expected," press release posted on  ScienceDaily Dec. 1, 2025.