In a Swedish study reported in JAMA Oncology, Mao et al found that women with a false-positive mammography result were more likely to be subsequently diagnosed with breast cancer compared to women with no false-positive result.
Study Details
The study involved data from 45,213 women who received a first false-positive mammography result between 1991 and 2017 and 452,130 control women matched for age, calendar year of mammography, and screening history of no previous false-positive result.
Key Findings
The 20-year cumulative incidence of breast cancer was 11.3% (95% confidence interval [CI] = 10.7%–11.9%) among women with a false-positive result vs 7.3% (95% CI = 7.2%–7.5%) among those without a false-positive result (adjusted hazard ratio [HR] = 1.61, 95% CI = 1.54–1.68).
Risk of breast cancer after a false-positive result was higher among women aged 60 to 75 years (HR = 2.02, 95% CI = 1.80–2.26) vs those aged 40 to 49 years at examination (HR = 1.38, 95% CI = 1.23–1.56, P < .001 for interaction). Risk was higher among women with a false-positive result who underwent biopsy at recall (HR = 1.77, 95% CI = 1.63–1.92) vs those who did not (HR = 1.51, 95% CI = 1.43–1.60).
Breast cancer diagnosed after a false-positive result was more likely to occur on the ipsilateral side of the false-positive result (HR = 1.92, 95% CI = 1.81–2.04). Subsequent breast cancers were more common during the first 4 years of follow-up, with hazard ratios of 2.57 (95% CI = 2.33–2.85) during the first 2 years and 1.93 (95% CI = 1.76–2.12) at > 2 to 4 years.
In a separate cohort of 1,113 women with a false-positive result and 11,130 matched controls with data on mammographic breast density, risk among those with a false-positive result was higher among those with lower density (computer-generated Breast Imaging Reporting and Data System density score [c-BI-RADS] of A and B, HR = 4.65, 95% CI = 2.61–8.29) than among those with higher density (c-BI-RADS of C and D, HR = 1.60, 95% CI = 0.93–2.73, P = .01 for interaction).
The investigators concluded, “This 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.”
Xinhe Mao, MSc, of the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, is the corresponding author for the JAMA Oncology article.
Disclosure: The study was supported by the Swedish Research Council, Swedish Cancer Society, and others. For full disclosures of the study authors, visit jamanetwork.com.
