Extra Weight Tied to Breast Cancer: Study

Extra weight tied to breast cancer: Study

Among women who have been treated for breast cancer, heavier women are more likely to have their disease come back and more likely to die of cancer, according to a US study. Previous studies have tied obesity to a higher chance of getting breast cancer and a worse outcome in women who have already been diagnosed. But the current study – which appeared in the journal Cancer – cancer makes the post-diagnosis picture clearer, said lead researcher Joseph Sparano, associate chairman of medical oncology at the Montefiore Einstein Center for Cancer Care in the Bronx New York.

“Obesity seemed to carry a higher risk of breast cancer recurrence and death, even in women who were healthy at the time that they were diagnosed, and despite the fact that they received the best available chemotherapy and hormone therapy,” he said. The relationship with weight may be because certain hormones that are linked to body weight in the most common form of the disease, known as estrogen receptor positive cancer."

Data for the study by the US National Cancer Institute of women with stage I, II and III breast cancer who were given standardized treatment, with drug doses adjusted based on weight. Out of close to 5,000 women treated for cancer, about one third were obese and another one-third were overweight. Over the next eight years, one four women had their cancer come back and 891 died – including 695 from breast cancer.

Sprano and his colleagues found that compared to women of normal weight, obese women were 40 percent more likely to have breast cancer recurrence over the study period and 69 percent more likely die from breast cancer or any other cause. Even among overweight but not obese women, there was also a general trend toward a higher risk recurrence and death with increasing weight. The link was especially strong for women with estrogen receptor positive cancer, which accounts for two thirds of breast cancers. Although the new study cant prove that extra weight have a direct impact on certain breast cancers, Sparano sait it was “biologically plausible”.

Women carrying extra fat have been shown to make more estrogen, meaning that this may fuel the growth of the estrogen receptor positive tumorsm he said. Insulin levels are known to be higher in patients who are obese because the develop insulin resistance….(and) insulin can stimulate the growth of breast cancer cells” he added. Whether women with the disease can improve their long-term outlook by loosing weight hasn’t been proven researchers said.