Invasive Breast Cancer Rising in Younger US Women

By Lou Portero - Last Updated: May 14, 2024

The number of young women aged 20 to 49 in the US diagnosed with invasive breast cancer increased between 2000 and 2019, according to a study in JAMA Network Open.

Advertisement

Research has shown that breast cancer in young women has a less favorable prognosis compared to older women. Young women are more likely to be diagnosed with aggressive breast cancer at an advanced stage and with larger tumors. However, there isn’t much clear information on how these cases change over time.

For this study, Dr. Shuai Xu and colleagues wanted to see how breast cancer rates changed in young women (aged 20 to 49) over 20 years in the US. They looked at these rates considering factors like race and ethnicity, hormone receptor status,  tumor stage, and age at diagnosis. Dr. Xu and the team also investigated how these rates might be influenced by when a woman was born (birth cohort).

The study looked at information of over 217 000 from an extensive database called SEER (Surveillance, Epidemiology, and End Results). Most participants in the study were between 20 and 49 years of age. Of the participants, about 58.3% were non-Hispanic White,  17.0% were Hispanic, 12.4% were non-Hispanic Black, 11.6% were Asian or Pacific Islander, and 0.7% were American Indian or Alaska Native. Furthermore, a majority of the participants (61.5%) had estrogen receptor (ER)-positive/progesterone receptor (PR)-positive disease and were diagnosed with a stage I tumor (37.6%).

The study showed that the number of new cases of invasive breast cancer increased with increasing trends across almost all racial and ethnic groups, especially after 2016. The study also found an overall increase in invasive breast cancer rates for ER+/PR+ and ER+/PR− tumors, whereas the rates decreased for ER−/PR+ and ER−/PR− tumors.

The study also found that Black women aged 20 to 39 had the highest rates of new invasive breast cancer cases compared to other races. However, for women between 40 and 49, this trend reversed, with White women having higher incidence rates.

The researchers further observed that rates of invasive breast cancer cases for stage II and III tumors decreased, while those for stage I and IV tumors increased.

“These results suggest that understanding factors driving differential trends in incidence rates for different age groups by race and ER-positive status should provide insights into breast cancer prevention in young women,” the researchers wrote.

The researchers also advised that breast cancer risk assessment should start at an early age in Black women to determine whether targeted screening should be recommended earlier in Black women at high risk.

Source: Oncology Nurse Advisor

Journal source: JAMA Network Open

 

Advertisement