Bariatric Surgery to Reduce Breast Cancer Risk?

The Fates“Bariatric surgery may be a powerful tool in breast cancer prevention and treatment,” write Trevor Crafts and colleagues in a new review paper for Obesity. But there’s just one problem. All of the research that points to this possible value is observational. So we need a prospective clinical trial of bariatric surgery to reduce the risk of breast cancer to be sure that this great potential can translate into a real clinical benefit.

A Powerful Tool?

Craft et al propose that this surgery could serve a dual purpose for reducing the harm of breast cancer in women with obesity.

First of all, they review the accumulating evidence that it might play a preventive role. Recently, Olivia Lovrics and colleagues completed a systematic review and meta-analysis of bariatric surgery’s effect on breast cancer incidence. They found it cut the risk in half. They also found that it increased the likelihood that breast cancer would be found at an earlier, more treatable stage.

In their review, Crafts et al tell us that research has consistently demonstrated an association between bariatric surgery and a lower risk of breast cancer subsequently. The association is strong, consistent, and biologically plausible as a causal relationship. Also, the timing of the observed effects line up. Yet it is all observational research. So it has all the usual limitations for proving surgery is responsible for these benefits.

An Adjuvant Role?

In addition to a role for prevention, Crafts et al see the potential for bariatric surgery as an adjuvant to treatment for breast cancer. This is because metastatic disease, recurrence, and mortality are all more likely with untreated obesity. They describe many reasons for this, ranging from biological mechanisms to practical considerations. Simply stated, untreated obesity can get in the way of effective long-term cancer care. Follow up is poorer and adequate dosing with chemotherapeutic agents is less likely.

A new study of bariatric surgery after breast cancer diagnosis suggests a benefit for survival. Of course, this is a retrospective, observational study.

No Substitute for Prospective Studies

The accumulating evidence is indeed impressive. But the fact remains that all of it is observational. So rigorous research is essential to bring better clarity, as Crafts explains:

“Bariatric surgery as a risk mitigation strategy in women at high risk for breast cancer and surgical weight loss to improve survivorship in women with obesity and breast cancer are important research targets.”

Breast cancer is the most common and second deadliest cancer in women. Obesity is a well-established risk factor for both incidence and outcomes. So the need to understand how better obesity care might reduce this burden of disease is indeed urgent.

Click here for the review paper by Crafts et al, here for the Lovrics paper, and here for further reporting. For a deeper dive into the metabolic pathways in obesity-related breast cancer, click here.

The Fates, painting by Gustav Adolf Mossa / WikiArt

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February 24, 2022