A universal benefit?
“Although these findings are important overall for the general population at risk for breast cancer, we raise an important caveat: The benefit of surgical weight loss may not be universal,” write Justin B. Dimick, MD, MPH, surgical innovation editor for JAMA Surgery, and Melissa L. Pilewskie, MD, both of the University of Michigan, Ann Arbor, in an accompanying commentary.
“In addition to lifestyle factors, several nonmodifiable risk factors, such as a genetic predisposition, strong family history, personal history of a high-risk breast lesion, or history of chest wall radiation, impart significant elevation in risk, and the data remain mixed on the impact of weight loss for individuals in these high-risk cohorts,” they add.
“Further study to elucidate the underlying mechanism associated with obesity, weight loss, and breast cancer risk should help guide strategies for risk reduction that are specific to unique high-risk cohorts, because modifiable risk factors may not portend the same benefit among all groups.”
Commenting on the findings, Stephen Edge, MD, breast surgeon and vice president for system quality and outcomes at Roswell Park Comprehensive Cancer Center, Buffalo, N.Y., said, “The importance of this study is that it shows that weight loss in midlife can reduce breast cancer risk back to or even below the risk of similar people who were not obese. This has major implications for counseling women.”
The investigators did not have information on the extent of weight loss with surgery or on which participants maintained the lower weight, Dr. Edge noted; “However, overall, most people who have weight reduction surgery have major weight loss.”
At this point, he said, “we can now tell women with obesity that in addition to the many other advantages of weight loss, their risk of getting breast cancer will also be reduced.”
The study was supported by the Ontario Bariatric Registry and ICES, which is funded by an annual grant from the Ontario Ministry of Health and the Ontario Ministry of Long-Term Care. Dr. Doumouras, Dr. Dimick, Dr. Pilewskie, and Dr. Edge reported no relevant financial relationships.
A version of this article first appeared on Medscape.com.