Impact of a false-positive screening mammogram on subsequent screening behavior and stage at breast cancer diagnosis

Abstract

Background: Experiencing a false positive (FP) screening mammogram is economically, physically, and emotionally burdensome, which may affect future screening behavior by delaying the next scheduled mammogram or by avoiding screening altogether. We sought to examine the impact of a FP screening mammogram on the subsequent screening mammography behavior. Methods: Delay in obtaining subsequent screening was defined as any mammogram performed more than 12 months from index mammogram. The Kaplan-Meier (product limit) estimator and Cox proportional hazards model were used to estimate the unadjusted delay and the hazard ratio (HR) of delay of the subsequent screening mammogram within the next 36 months from the index mammogram date. Results: A total of 650,232 true negative (TN) and 90,918 FP mammograms from 261,767 women were included. The likelihood of a subsequent mammogram was higher in women experiencing a TN result than women experiencing a FP result (85.0% vs. 77.9%, P < 0.001). The median delay in returning to screening was higher for FP versus TN (13 months vs. 3 months, P < 0.001). Women with TN result were 36% more likely to return to screening in the next 36 months compared with women with a FP result HR = 1.36 (95% CI, 1.35-1.37). Experiencing a FP mammogram increases the risk of late stage at diagnosis compared with prior TN mammogram (P < 0.001). Conclusions: Women with a FP mammogram were more likely to delay their subsequent screening compared with women with a TN mammogram. Impact: A prior FP experience may subsequently increase the 4-year cumulative risk of late stage at diagnosis.