Up to 24% of breast cancers diagnosed in an 11-year period between seven outpatient facilities around New York were found in women aged 18 to 49 years, according to findings presented during the 2025 Annual Meeting of the Radiological Society of North America (RSNA; Abstract S5-SSBR02-1).
“This research shows that a significant proportion of cancers are diagnosed in women under 40, a group for whom there are no screening guidelines at this time,” stated presenting author Stamatia Destounis, MD, Radiologist, Elizabeth Wende Breast Care (EWBC) in Rochester, New York. “Consideration must be given by physicians caring for women in this age group to performing risk assessment in order to identify those who may benefit from more intensive screening due to being higher risk.”
Study Methods
The study authors conducted a retrospective review of longitudinal trends for women aged 18 to 49 who were diagnosed with breast cancer between 2014 and 2024. Women in this age group represent 21% to 25% of the annual volume of a community outpatient breast imaging facility in New York. Cases of non-primary breast cancer were excluded.
Key Findings
In this time period, 1,799 breast cancers were diagnosed in 1,290 women aged 18 to 49 years. Annually, 145 to 196 cases were diagnosed in this age group, with a mean age of 42.6 years. Among these cancers, 731 (41%) were detected by screening and 1,068 (59%) on diagnostic evaluation.
The majority of these cancer diagnoses were invasive breast cancers (80.7%) and intermediate- (43.9%) or high-grade tumors (33%). Only 8.6% of patients had a diagnosis of triple-negative breast cancer.
Twenty-four percent of these breast cancers were diagnosed in women under 40 years, which falls below the recommended age for mammography screenings. Annually, breast cancer was diagnosed in 17 to 56 women under 40 years. This amount peaked in 2019.
The rates of women in this age group who were diagnosed with breast cancer was 24%, which declined to 21% by 2024, but the absolute number of breast cancers remained stable for the age group.
Findings from this review highlight a need to re-evaluate age-based screening thresholds and risk stratification strategies. “This is striking because it shows that younger women not only carry a stable and substantial share of the breast cancer burden, but their tumors are often biologically aggressive,” Dr. Destounis said. “That combination—steady incidence plus disproportionately aggressive biology—directly challenges age-based screening cutoffs and strengthens the case for earlier, risk-tailored screening approaches.”
“That means this problem is not going away,” she added. “It is here to stay and needs to be addressed on a larger scale."
Disclosure: For full disclosures of the study authors, visit rsna.org.
