Breast Cancer Incidence After a False-Positive Mammography Result

Abstract

ImportanceFalse-positive mammography results are common. However, long-term outcomes after a false-positive result remain unclear.ObjectivesTo examine long-term outcomes after a false-positive mammography result and to investigate whether the association of a false-positive mammography result with cancer differs by baseline characteristics, tumor characteristics, and time since the false-positive result.Design, Setting, and ParticipantsThis population-based, matched cohort study was conducted in Sweden from January 1, 1991, to March 31, 2020. It included 45 213 women who received a first false-positive mammography result between 1991 and 2017 and 452 130 controls matched on age, calendar year of mammography, and screening history (no previous false-positive result). The study also included 1113 women with a false-positive result and 11 130 matched controls with information on mammographic breast density from the Karolinska Mammography Project for Risk Prediction of Breast Cancer study. Statistical analysis was performed from April 2022 to February 2023.ExposureA false-positive mammography result.Main Outcomes and MeasuresBreast cancer incidence and mortality.ResultsThe study cohort included 497 343 women (median age, 52 years [IQR, 42-59 years]). The 20-year cumulative incidence of breast cancer was 11.3% (95% CI, 10.7%-11.9%) among women with a false-positive result vs 7.3% (95% CI, 7.2%-7.5%) among those without, with an adjusted hazard ratio (HR) of 1.61 (95% CI, 1.54-1.68). The corresponding HRs were higher among women aged 60 to 75 years at the examination (HR, 2.02; 95% CI, 1.80-2.26) and those with lower mammographic breast density (HR, 4.65; 95% CI, 2.61-8.29). In addition, breast cancer risk was higher for women who underwent a biopsy at the recall (HR, 1.77; 95% CI, 1.63-1.92) than for those without a biopsy (HR, 1.51; 95% CI, 1.43-1.60). Cancers after a false-positive result were more likely to be detected on the ipsilateral side of the false-positive result (HR, 1.92; 95% CI, 1.81-2.04) and were more common during the first 4 years of follow-up (HR, 2.57; 95% CI, 2.33-2.85 during the first 2 years; HR, 1.93; 95% CI, 1.76-2.12 at >2 to 4 years). No statistical difference was found for different tumor characteristics (except for larger tumor size). Furthermore, associated with the increased risk of breast cancer, women with a false-positive result had an 84% higher rate of breast cancer death than those without (HR, 1.84; 95% CI, 1.57-2.15).Conclusions and RelevanceThis study suggests that the risk of developing breast cancer after a false-positive mammography result differs by individual characteristics and follow-up. These findings can be used to develop individualized risk-based breast cancer screening after a false-positive result.

Clinical outcomes of screening and diagnostic mammography in a limited resource healthcare system

“…During the audit, various rates are calculated, including the recall rate, which indicates the percentage of screened patients requiring further ultrasound or mammographic examinations. This rate is positively correlated with the likelihood of a false-positive result and is influenced by factors such as image quality and quantity, screening interval, single versus double reading, screening technique, and characteristics of the women being screened (e.g., age, use of hormonal therapy) [ 12 , 13 ]​.…”

“…Women who are recalled for additional evaluation are at a higher likelihood of having breast cancer, particularly if they undergo a needle biopsy. As a result, such recalls can be distressing for patients [ 12 ].…”