Assoc. Prof. Dr. Abdulcabbar Kartal
Digestive System surgery and
Coloproctology Specialist
The association between obesity and certain cancers has been well established. According to the International Agency for Research on Cancer Handbook Working Group, the 13 types of obesity-associated cancer include esophageal cancer, renal cell cancer, breast cancer (in postmenopausal or oophorectomized younger patients), gastric cardia cancer, colon cancer, rectal cancer, liver cancer, gallbladder cancer, pancreatic cancer, ovarian cancer, uterine cancer, thyroid cancer, and multiple myeloma. Obesity also increases the likelihood of worse oncologic outcomes.
In a database study of over 16,000 patients, patients who underwent bariatric surgery had a decreased risk of hormone-related cancers including, endometrium and prostate cancer, compared with matched patients who did not have surgery. Roux-en-Y gastric bypass (RYGB) resulted in the largest risk reduction for hormone-related cancers but was associated with an increased risk for colorectal cancer. Adjustable gastric band (AGB) and sleeve gastrectomy (SG) were not associated with any increased risk of colorectal cancer.
In another multisite database study, 22,000 patients who underwent bariatric surgery (61 percent RYGB and 27 percent SG) had a 33 percent lower hazard of developing any cancer during the mean follow-up period of 3.5 years compared with over 66,000 matched patients who did not undergo surgery. Bariatric surgery was associated with a lower risk of developing postmenopausal breast cancer, endometrial, pancreatic, and colon.
A French database study of over one million patients suggested that, following bariatric surgery, patients with obesity shared the same risk of colorectal cancer as the general population, whereas for patients with obesity who did not undergo bariatric surgery, the risk is 34 percent above that of the general population.
In another multi-database study of 28,000 bariatric surgery-eligible patients, postoperative rates of any cancer type and lung, ovarian, and uterine cancer were significantly lower in patients undergoing either vertical sleeve gastrectomy or RYGB compared with nonsurgical control patients.
In another retrospective study of 5053 patients who underwent bariatric surgery and 25,265 matched patients in the nonsurgical control group, bariatric surgery was associated with a lower risk of obesity-associated cancer and cancer-related mortality.
Studies using the Swedish Obese Subjects (SOS) Database associated bariatric surgery with a reduction of cancer risk over 20 years from 6 to 3.9 percent, and the effect was more pronounced in women. A study using the Utah Cancer Registry showed that cancer mortality was reduced by 46 percent in patients who underwent bariatric surgery.
Bariatric surgery has also been associated with a reduced risk of all skin cancers including melanoma.
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