Decrease Seen in In Situ Breast Cancer Since 2009

MONDAY, Jan. 6, 2025 (HealthDay News) — The incidence of in situ breast cancer has decreased since 2009, consistent with decreasing use of mammography in association with the 2009 U.S. Preventive Services Task Force (USPSTF) guideline change, according to a study published online Dec. 27 in JAMA Network Open.

Carina Zhang-Petersen, M.D., from the University of Vermont in Burlington, and colleagues examined the incidence of breast cancer by stage at diagnosis and surgical treatment before and after the 2009 guideline change in an epidemiologic cohort study of women aged 40 years or older using 2004 to 2019 data.

Data were included for 2,022,250 women (17.5, 63.2, and 19.2 percent aged 40 to 49, 50 to 74, and 75 years and older, respectively) diagnosed with breast cancer. The researchers found that since 2009, there was a decrease in rates of in situ breast cancer (e.g., annual percent change [APC], −0.69 for women aged 50 to 74 years). During 2004 to 2019, localized breast cancer rates increased steadily among women aged 40 to 74 years (e.g., APC, 1.18 for women aged 50 to 74 years); during the study period, there was no evidence for a change in trend. Since 2012, distant cancer rates were flat among women aged 40 to 74 years and increased steadily for those aged 75 years and older during 2004 to 2019.

“The incidence of in situ breast cancer decreased with the decrease in use of screening mammography dating back to the 2009 USPSTF guideline change,” the authors write. “However, to date, there does not appear to be evidence that reductions in screening and in situ breast cancer diagnoses have translated to increases in the incidence of more advanced stage breast cancer.”

Abstract/Full Text