According to the results of a study published in the Archives of Surgery, pancreatic caner patients with a body mass index (BMI) greater than 35 have a greater risk of recurrence and worse survival after surgery than patients with a lower BMI.
Obesity is increasingly being recognized as a risk factor not only for cancer development, but also for worse outcomes after cancer treatment. Links between obesity and endometrial cancer, postmenopausal breast cancer, and colorectal cancer are well established, but the effects of obesity appear to extend to several other types of cancer as well. According to the results of a large study conducted by the American Cancer Society, women with the highest BMIs were more likely than women with a healthy BMI to die of cancers of the gallbladder, pancreas, kidney, cervix, and ovary, as well as non-Hodgkin’s lymphoma. The researchers estimated that 90,000 cancer deaths per year could be prevented if Americans maintained a healthy weight.
BMI is a commonly used (though imperfect) measure of body size. It involves a comparison of weight to height (weight in kilograms divided by height in meters squared). A BMI between 18.5 and 24.9 is generally considered healthy, a BMI between 25 and 29.9 is considered overweight, and a BMI of 30 or higher is considered obese.
To explore the relationship between BMI and survival after surgery for potentially curable pancreatic cancer, researchers evaluated the medical records of 285 patients. The results suggested patients with a BMI of 35 or greater had worse outcomes after surgery:
- Risk of lymph node metastasis was 12-times higher among patients with a BMI greater than 35 than among patients with a BMI of 35 or less.
- Risk of cancer recurrence and death was almost twice as high among patients with a BMI greater than 35.
These results suggest that very obese individuals have worse survival after surgery for potentially curable pancreatic cancer. The researchers note that at least some of this effect appears to be due to different tumor biology in obese individuals.
 Calle EE, Rodriguez C, Walker-Thurmond K, Thun MJ. Overweight, obesity, and mortality from cancer in a prospectively studied cohort of U.S. adult. New England Journal of Medicine. 2003;348:1625-38.