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Clinical Risk Factors for Breast Cancer

JAMA Oncol; ePub 2017 Feb 2; Engmann, et al

At the time of mammography, most women with breast cancer have at least 1 breast cancer risk factor routinely documented, and more than half of premenopausal and postmenopausal breast cancers are explained by these factors, a recent study found. This case-controlled study sought to determine the population-attributable risk proportion (PARP) for breast cancer associated with clinical breast cancer risk factors among premenopausal and postmenopausal women. It included 18,437 women with invasive breast cancer or ductal carcinoma in situ who were matched to 184,309 women without breast cancer. Researchers found:

  • 4,747 (89.8%) premenopausal and 12,502 (95.1%) postmenopausal women with breast cancer had at least 1 breast cancer risk factor.
  • Combined PARP of all risk factors was 52.7% (premenopausal) and 54.7% (postmenopausal).
  • Breast density was the most prevalent risk factor for both groups and had the largest effect on the PARP.
  • 22.8% of breast cancer in postmenopausal women could potentially be averted if all overweight and obese women attained a body mass index of <25.


Engmann NJ, Golmakani MK, Miglioretti DL, et al, for the Breast Cancer Surveillance Consortium. Population-attributable risk proportion of clinical risk factors for breast cancer. JAMA Oncol. [Published online ahead of print February 02, 2017]. JAMA Oncol. doi:10.1001/jamaoncol.2016.6326.