Incidence of Breast Cancer After False-Positive Mammography

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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

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.