Obesity and the risk of pancreatic cancer. An Italian multicenter study

OBJECTIVE: The purpose of this work was to determine whether obesity is a risk factor for pancreatic cancer. METHODS: We studied 400 patients with this tumor and 400 controls matched for sex and age from various Italian cities. We used a standardized questionnaire that was compiled at personal interview, with particular attention to body weight at the time of the interview, and for those with the tumor, their weight before onset of the disease. Body mass index (BMI) was calculated as the patient's weight in kilograms divided by their height in meters squared. RESULTS: The risk of pancreatic cancer adjusted for smoking was 5-fold higher (P < 0.001) in patients with a BMI less than 23 kg/m2 after diagnosis compared with patients with a BMI ranging from 23 to 29.9 kg/m2, whereas the risk in patients with BMI of at least 30 kg/m2 was not significant (P = 0.689). Taking into account BMI before diagnosis, smoking was confirmed as a significant risk factor (odds ratio = 1.68; P = 0.001) for pancreatic cancer, whereas no significant relationship was found between BMI classes and the risk of pancreatic cancer (P = 0.984). CONCLUSIONS: These findings indicate that obesity is not a risk factor for pancreatic cancer.