Clinicians Not Fully Identifying Postmenopausal Women at Risk for Invasive Breast Cancer

July 2, 2011
Heidi Anne Duerr, MPH

Breast cancer causes more than 40,000 deaths annually and is only second to lung cancer in cause of cancer deaths in women in the United States. Since early identification is key to prompt treatment and the best prognosis, it is crucial to identify women at risk.

Breast cancer causes more than 40,000 deaths annually and is only second to lung cancer in cause of cancer deaths in women in the United States. Since early identification is key to prompt treatment and the best prognosis, it is crucial to identify women at risk.

The Gail model, which is based on a multivariate model that uses several risk factors including family history of breast cancer, is the only validated risk assessment tool for the general population. The National Cancer Institute developed the online Breast Cancer Risk Assessment (BCRA) tool to calculate the absolute risk for developing invasive breast cancer (IBC) over a period of 5 years as well as the lifetime risk, but it is not commonly used by clinicians to asses their patients’ risk. In fact, only 3% of primary care providers surveyed said they usually calculated Gail scores, and 76% said they never calculate risk. Furthermore, studies suggest that physicians rely on a family history to identify women at risk, but since there are other risk factors, this strategy ignores a segment of the population who may be at risk.

To better understand who may be most at risk, researchers performed posthoc analyses using the Continuing Outcomes Relevant to Evista (CORE) and Raloxifene Use for the Heart (RUTH) trial data to characterize the prevalence of breast cancer risk factors as defined in the Gail model in postmenopausal women. The CORE study was a randomized, placebo-controlled, multicenter international trial of postmenopausal women 80 years or younger with documented osteoporosis; 1275 women from the placebo arm of the trial who had known breast cancer risk factor scores were enrolled as part of this analysis. The researchers also looked at 5047 postmenopausal women from the placebo arm of the RUTH trial, for a total sample of 6322 women.

The researchers found that approximately 2 of 3 women from the CORE group had a Gail score of 1.66% or higher. Furthermore, they noted that more than half (56%) the women without family risk factors were considered to be at high risk for breast cancer (although the risk for women with a family history was higher). The researchers also found that the number of breast cancer cases correlated with the risk estimates.

Interestingly, they found that most cases of breast cancer occurred in women with a modest risk estimate, which is consistent with the American Cancer Society estimate that most cases of breast cancer occur in women with no family history of breast cancer. “In other words,” the researchers explained, “many more women did not have FHBC [family history of breast cancer] yet still developed IBC because of the conferred risk from a combination of other risk factors.”

“The implications of these findings for clinicians and women are that all postmenopausal women are at risk of developing breast cancer and that risk factors other than FHBC are important contributors,” the authors concluded. “Assessing risk for breast cancer based on family history alone identifies only a subset of women at increased risk of breast cancer and underscores the importance of assessing a broader range of risk factors or using a validated tool such as the BCRA tool.”
 

More Information

Breast Cancer Risk Assessment ToolAmerican Cancer Society

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References:

Reference
Sontag A, Wickerham L, Ni X et al. Estimated risk of invasive breast cancer in postmenopausal women with and without family history of the disease. Menopause. 18(5):515/520.