Physical activity, anthropometric factors and risk of pancreatic cancer: Results from the Canadian Enhanced Cancer Surveillance System

To explore the hypothesis that insulin resistance may be an etiologic facto r in pancreatic cancer, we assessed the pancreatic cancer risk associated w ith anthropometric factors and physical activity, both of which are importa nt determinants of insulin sensitivity in humans. Three hundred and twelve patients with histologically confirmed pancreatic cancer were compared to 2 ,919 controls in a population-based, case-control study in 7 of the 10 Cana dian provinces. Participants were asked to report their exposure status for the period 2 years before interview. Men in the highest quartile of body m ass index (BMI, greater than or equal to 28.3 kg/m(2)) were at increased ri sk of pancreatic cancer [adjusted odds ratio (OR) = 1.90, 95% confidence in terval (CI) 1.08-3.35]. In addition, men who reported a decrease in weight of at least 2.9% from their lifetime maximum were at reduced risk compared to those reporting a less than or equal to2.9% loss ( greater than or equal to 10.2% loss, OR = 0.51, 95% CI 0.30-0.86). BMI 2 years before interview was not associated with pancreatic cancer risk among women, though those re porting a greater than or equal to 12.5% decrease in weight from their life time maximum had substantially lower risk compared to those in the baseline quartile (OR = 0.53, 95% CI 0.29-0.99). After adjustment for age, province of residence, dietary intake and anthropometric factors, men in the highes t quartile of the composite moderate and strenuous physical activity index were at reduced risk of pancreatic cancer (OR = 0.53, 95% CI 0.31-0.90). Ph ysical activity did not appear to be associated with pancreatic cancer amon g women, though a tendency for reduced risk with increasing levels of stren uous activity was suggested (p for trend = 0.06). Our findings support the hypothesis that insulin resistance is an etiologic factor in the developmen t of pancreatic neoplasms among men and possibly women. (C) 2001 Wiley-Liss , Inc.