Body Mass Index and Risk, Age of Onset, and Survival in Patients with Pancreatic Cancer
Obesity has been implicated as a risk factor for pancreatic cancer. As a result, a study published in the Journal of the American Medical Association (2009;301:2553-2562) was performed to evaluate whether there was an association of excess body weight across an age cohort with the risk, age of onset, and overall survival of patients with pancreatic cancer. The investigation was a case-control study of 841 patients with pancreatic adenocarcinoma and 754 healthy individuals frequency matched by age, race, and gender. height and body weight histories were collected by personal interview starting at ages 14 to 19 years and over 10-year intervals progressing to the year prior to recruitment in the study. The main outcome measures were the associations between patients’ body mass index (BMI) and risk of pancreatic cancer, age at onset, and overall survival. Results showed that individuals who were overweight (a BMI of 25-29.9) from the ages of 14 to 39 years or obese (a BMI > 30) from the ages of 20 to 49 years, had a 1.7 and 2.6 increased risk of pancreatic cancer, respectively. This risk was independent of diabetes status and an association was stronger in men. The population-attributable risk percentage of pancreatic cancer based on the mean BMI from the ages of 14 to 59 years was 10.3% for never smokers and 21.3% for ever smokers. Individuals who were overweight or obese from the ages of 20 to 49 years had an earlier onset of pancreatic cancer by 2 to 6 years (median age of onset was 64 years for patients with normal weight, 61 years for overweight patients, and 59 years for obese patients [P < .001]). Compared with those with normal body weight and after adjusting for all clinical factors, individuals who were overweight or obese from the ages of 30 to 79 years, or in the year prior to recruitment, had reduced overall survival of pancreatic cancer regardless of disease stage and tumor resection status. According to the authors, overweight or obesity during early adulthood was associated with a greater risk of pancreatic cancer and a younger age of disease onset and that obesity at an older age was associated with a lower overall survival in patients with pancreatic cancer.