The impact of obesity on survival is becoming very apparent as more studies are added that continue to validate previous findings. Unfortunately, translation into clinical practice is delayed.
A summary by Meg Barbor from the Cancer Survivorship Symposium in the May 10, 2018 edition of the ASCO Post further clarifies just how much weight matters. A meta-analysis of over 200,000 women followed in 82 studies showed a 41% decrease in survival in obese patients compared to those of normal weight. These results may also apply to patients who have estrogen receptor negative disease as demonstrated in some studies. What remains unclear is the relationship between weight loss and survival outcomes. Several randomized trials are addressing this question such as the BWEL, DIANA5, SUCCESS C, LIVES, CHALLENGE, and GAP trials.
Weight loss has been shown to decrease inflammatory markers such as C-reactive protein, which may, at least partially, explain some of the potential benefits of caloric restriction. Other benefits are derived from a profound reduction in other disease such as type 2 diabetes and cardiovascular disease with as little as 3-5% weight loss.
Survivors experience additional challenges with weight loss related to depression, menopause, and reduced activity. Such obstacles can and should be addressed more aggressively as success is possible. Take, for example, the ENERGY Trial. Successful weight loss was achieved using intensive dietician-led face-to-face counseling over the course of 2 years. This plan entailed weekly visits for the first 4 months with gradual tapering to biweekly and then monthly follow-up. Email and telephone communications were added between sessions. Although, this is intense, the outcomes may be worth it to individual patients. In fact, such an intervention may produce cure rates similar to those observed with other cancer treatments. In the meantime, it is certainly worth addressing any weight concerns with your oncology dietician or even another dietitian under the care of your family doctor or oncologist.