Literature review finds very low risk
Dr. Freedman and colleagues conducted a literature review of the risk for ipsilateral and contralateral breast cancer events among survivors and of the harms and benefits associated with mammography. Following the literature review, a multidisciplinary expert panel, which included patients and patient advocates, was convened to develop consensus guidelines.
The literature review confirmed that there was a low risk for in-breast cancer events in this population and that the risk was particularly low among patients who undergo treatment with endocrine therapy. Among those who did not receive systemic therapy for ERBB2-positive or triple-negative cancers, the rates of ipsilateral recurrence were estimated to be higher.
On the basis of the literature review, the estimated 10-year risk for in-breast cancer events ranged from 1% to 15% for ipsilateral breast cancers and from 1% to 5% for contralateral cancers. Among women in the same age group who did not have a history of breast cancer, the 5-year risk of developing the disease (average risk) was 2.2%.
The authors note that these findings mirror their estimates for new breast cancers among survivors who had low-risk disease. The findings are also similar to those cited in a large-scale mammography study, in which breast cancer survivors aged 70-80 years had a 1.1% annual risk for in-breast cancers. The risk was 0.7%-0.9% for similarly aged patients who did not have a history of breast cancer.
The benefits associated with mammography for older women are not well defined, but the literature suggests that mammography offers little to modest clinical benefit for patients in this age group. The limited benefits are likely because of the more than 10-year time lag that is needed to detect the small improvements in breast cancer mortality; slow-growing tumors generally do not affect the life expectancy of older women, they point out.
“Through our expert consensus process and after iterative feedback from clinicians, we created guidelines to support patients and clinicians in making individualized decisions on how and when to stop mammography,” said Dr. Freedman. “These guidelines are based on the risk of a breast cancer returning in the breast, one’s underlying health, and one’s preferences.”
The guidelines are also intended to provide information to patients on the benefits and harms of mammography in this setting, in addition to “how much we anticipate a mammogram may or may not continue to help a woman over time,” she said.
A companion guide for patients on these guidelines will be published in the coming months.
Dr. Freedman has received institutional clinical trial funding from Eisai and Puma Biotechnology outside the submitted work.
A version of this article first appeared on Medscape.com.