Screening mammography for women in their 40s: a retrospective study of the potential impact of the U.S. Preventive Service Task Force's 2009 breast cancer screening recommendations.

OBJECTIVE: The objective of our study was to review screening mammography examinations performed at our institution from 2007 through 2010 with the primary endpoint of determining the incidence of breast cancer and associated histologic and prognostic features in women in their 40s.

MATERIALS AND METHODS: Patients who presented for screening mammography who ultimately (i.e., after additional imaging, including diagnostic mammographic views and ultrasound) received a BI-RADS assessment of a category 4 or 5 for a suspicious abnormality were followed retrospectively through completion of care and were analyzed with respect to pathology results after biopsy, treatment, and family history.

RESULTS: During the study period, 43,351 screening mammography examinations were performed; 1227 biopsies were recommended on the basis of those studies and yielded 205 breast cancers (cancer detection rate of 4.7 per 1000 screening examinations). These screening examinations included 14,528 (33.5%) screening examinations of patients in their 40s; 413 biopsies were recommended and yielded 39 breast cancers (39/205 = 19%) (cancer detection rate of 2.7 per 1000 screening examinations). More than 50% (21/39) of the cancers in women in their 40s were invasive. Only 8% (3/39) of the women in their 40s with screening-detected breast cancer had a first-degree relative with breast cancer.

CONCLUSION: From 2007 through 2010, patients in their 40s accounted for one third of the population undergoing screening mammography and for nearly 20% of the screening-detected breast cancers--more than half of which were invasive. This information should be a useful contribution to counseling women in this age group when discussing whether or not to pursue regular screening mammography.