There is already a long list of reasons to stay in shape or shed pounds ranging from having more energy to staving off heart disease. Last month, researchers added another – those extra pounds can raise the risk of breast cancer coming back.
Women who were overweight or obese when they were diagnosed with the most common types of cancer were more likely to have a recurrence than their slimmer counterparts, according to the study led by Dr. Joseph Sparano, associate chairman of oncology at New York City’s Montefiore Medical Center. Despite having the most optimal therapy, obese women had a 30 percent greater risk of recurrence and a 50 percent increased risk of death.
The study published online in the journal Cancer showed a correlation only for one subtype of cancer, that which is hormone receptor-positive, but this accounts for two-thirds of all cases worldwide.
The study was also not able to show why heavier women were at a greater risk. It could be that they produce more estrogen, which the cancer needs to grow, researchers speculated. It was clear, however, that as body mass index (BMI) rose, the risk of recurrence or death increased incrementally. Being overweight but not obese also increased risk, although it wasn’t clear exactly when weight started to matter. The big question left unanswered is, however, whether reducing weight after cancer treatment can lower the risk.