Stage IV Non-breast Cancer Patients and Screening Mammography: It is Time to Stop.

Background: Patients diagnosed with metastatic cancer have shortened life expectancy with questionable benefit of routine screening mammography (SM). The aim of this study was to evaluate the incidence and consequences of continued SM in the setting of reduced survival from stage IV non-breast cancer.

Methods: Women diagnosed with Stage IV non-breast cancer at a single institution from 2015 to 2019 were queried from the institutional tumor registry for demographics, stage IV cancer diagnosis, and survival. Incidence and timing of SM after stage IV diagnosis and further diagnostic workup were extracted from the medical record.

Results: 790 women with Stage IV non-breast cancer were identified, 109 (14%) had at least 1 SM, 23% required diagnostic mammography, 7% breast biopsy, and 1% breast surgery. No breast cancers were identified. SM was ordered most often in stage IV gynecological cancers (28%), with more common cancers still seeing a high percentage of patients screened (lung 10%, colorectal 15%). Study 3-year survival was 26% (95% confidence interval [CI] 23-30%), with 74% mortality during follow up and median time from Stage IV diagnosis to death of 1.2 years (CI 0.4-2.3 years). Of patients screened, 41/109 died within 2 years of undergoing SM.

Conclusions: Despite low overall survival for patients diagnosed with metastatic non-breast cancer, 14% of women underwent SM which resulted in additional imaging, biopsies, and surgery with no new breast cancers identified. Continued SM in this population offers risk without benefit of reduced breast cancer mortality and should no longer continue in women with stage IV non-breast cancer.