Prevalence of cancer in Italian obese patients referred for bariatric surgery

Background: An association between obesity and cancer has been shown in large epidemiological studies. The aim of this study was to evaluate the prevalence and types of malignancies in an Italian cohort of obese patients referred to a bariatric center. Methods: A retrospective, observational study was conducted. Between Jan 1996 and Dec 2004, 1,333 obese patients (M=369, F=964) were seen in the center for minimally invasive treatment of morbid obesity. Morbid obesity were considered as BMI > 40 kg/m(2) or BMI > 35 kg/m(2) with at least one co-morbidity. Obese and morbidly obese patients who suffered any form of cancer were reviewed. Results: 43 patients (3.2%) presented various malignancies, with 88.3% in females. The prevalence of cancer in the younger group (21-46 years) was higher than in the older group (47-70 years), 2.1% vs 1.1%. 26 obese patients out of the 43 (60.5%) (age 41 +/- 7.9 years, BMI 38.2 +/- 9.9) presented hormone-related tumors. The most frequent site of cancer was breast (20.9%), followed closely by thyroid. Conclusion: This is the first Italian report on prevalence of cancer in a homogeneous obese population attending an academic bariatric center. The morbidly obese patients appear to have a higher risk of developing cancer, with a higher prevalence of hormone-related tumors. The predominant gender affected by both obesity and cancer was female. Thus, a preoperative work-up for cancer screening is indicated in this group of patients.