Cancer in obese women: potential protective impact of bariatric surgery

The use of bariatric surgery has been increasing over the last several years in response to the obesity epidemic, and the objective of this study was to report on the types of cancer in morbidly obese women undergoing bariatric surgery and compare these with types of cancer in obese women without surgery.

A retrospective, observational study was conducted. The bariatric surgery database identified women who underwent operations between 1990 and 2006 at the University of Virginia. Medical records and the institution's and state's cancer registries were searched for demographics and cancer data. Morbidly obese patients not undergoing bariatric surgery were used for comparison.

There were 1,482 women who had bariatric surgery, and 53 of these (3.6%) were diagnosed with cancer. The most common cancer site was the breast (n = 15, 28.3%) followed by the endometrium (n = 9, 17%) and the cervix (n = 6, 11.3%). The mean age at cancer diagnosis was 39.4 years. Most cancers (n = 34, 64.1%) were diagnosed before the bariatric surgery. Bariatric surgery patients with cancer were older than noncancer patients at time of surgery (mean age 44.7 versus 41.6 years; p=0.019), but otherwise did not differ significantly with regard to race, body mass index, or comorbid conditions. Compared with a control group of 3,495 morbidly obese women who had not undergone bariatric surgery, the surgery patients had fewer cancers (3.6% versus 5.8%, p=0.002), were younger (41.7 versus 46.9 years, p < 0.001), and were younger at cancer diagnosis (45.0 versus 56.8 years, p < 0.001). The most frequent cancers in the control obese women were endometrial, ovarian, and breast cancer. Both groups of obese women with endometrial, breast, ovarian, and colorectal cancers were younger at diagnosis compared with Virginia Cancer Registry means.

Breast and endometrial cancers remain the most common types in obese women and may occur at young ages; bariatric surgery may decrease cancer development in obese women.