Abstract P4-03-09: Risk of breast cancer after false-positive mammography recalls: a matched cohort study

Abstract

Abstract Background: False-positive mammography recalls are common and associated with an increased risk of subsequent breast cancer. But the long-term risk and whether the risk restricts to the breast cancer detected on the false-positive recalled side remain unclear. Objective: To examine long-term risk of breast cancer after false-positive recalls by side of breasts, mode of detection and tumor characteristics. Design: Matched cohort. Setting: The mammography screening program in Stockholm, Sweden. Participants: We included 45,588 women who received false-positive recalls (1991-2017) and 455,880 matched women who were not recalled, and then followed them until March 31st, 2020. Measurement: Breast cancer incidence; mode of breast cancer detection; tumor characteristics; re-attendance at mammography screening. Results: With Kaplan-Meier curves, we showed that women with false-positive recalls were more likely than those without to have breast cancers, on not only the previously recalled (false-positive) side but also the unrecalled side, up to at least 20 years since the next scheduled screen. We further found that risks were particular higher for breast cancer diagnosed on the false-positive side within first four years of follow-up (hazard ratio [HR]: 2.40; 95% confidence interval [CI]: 2.17-2.65), by the use of stratified Cox model while allowing for time-varying effects. In addition, when stratifying by age at matched mammograms, we found the association was stronger among old women (60-74) than young women (40-59). This was consistent with the result that the risk of breast cancer was higher among women with low density than those with high density. Of note, within the first four years, women with false-positive recalls were at an increased risk of clinical detected cancers (cancer detected among women who did not attend last scheduled screen or were at an age out of screening age ranges) on the false-positive side compared with those who were not recalled. In addition, we found that women with false-positive recalls had statistically significantly lower re-attendance rates at every of next five scheduled screenings. Conclusion: Women with false-positive recalls are at an increased risk of breast cancer for at least two decades, while these women are less likely to adhere to subsequent mammography screens comparing to women who were not recalled. Thus, women with false-positive recalls, especially older women, should be encouraged to re-attend the mammography screening program. Citation Format: Xinhe Mao, Wei He, Keith Humphreys, Haomin Yang, Kamila Czene. Risk of breast cancer after false-positive mammography recalls: a matched cohort study [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-03-09.