Obesity, Recreational Physical Activity, and Risk of Pancreatic Cancer In a Large U.S. Cohort

Abstract

Background: Obesity and physical activity, in part through their effects on insulin sensitivity, may be modifiable risk factors for pancreatic cancer. Methods: The authors analyzed data from the American Cancer Society Cancer Prevention Study II Nutrition Cohort to examine the association between measures of adiposity, recreational physical activity, and pancreatic cancer risk. Information on current weight and weight at age 18, location of weight gain, and recreational physical activity were obtained at baseline in 1992 via a selfadministered questionnaire for 145,627 men and women who were cancer-free at enrollment. During the 7 years of follow-up, 242 incident pancreatic cancer cases were identified among these participants. Cox proportional hazards modeling was used to compute hazard rate ratios (RR) and to adjust for potential confounding factors including personal history of diabetes and smoking.

Obesity, physical activity and the risk of pancreatic cancer in a large Japanese cohort

“…In studies carried out in the U.S.A., a positive relationship was demonstrated for both men and women in the 3 largest cohort studies, [15][16][17] while 4 other smaller studies found a positive association only in men. 10,22,26,33 The 6 other studies, including the 2 largest European cohort studies, 6,[18][19][20][21]35 did not find any significant association in the combined data of men and women.…”

“…Since 2000, at least 13 prospective cohort studies carried out in Western countries have reported a link between BMI and pancreatic cancer risk, 6,10,[15][16][17][18][19][20][21][22]26,35 although the findings have been inconsistent. In studies carried out in the U.S.A., a positive relationship was demonstrated for both men and women in the 3 largest cohort studies, [15][16][17] while 4 other smaller studies found a positive association only in men.…”

“…This finding is consistent with those of 2 U.S.A. cohort studies. 15,16 Michaud et al examined the relationship between weight loss and the risk of pancreatic cancer in the Nurses' Health Study and the Health Professionals Follow-up Study, and reported that individuals who had lost 6.75 kg or more between 2 consecutive biennial questionnaires had an RR of 4.56 (95% CI, 2.35-8.84) for men and 2.44 (95% CI, 1.46-4.06) for women. 15 Data from the American Cancer Society Cancer Prevention Study II Nutrition Cohort showed that weight loss of 2.27 kg or more between 18 years of age and 1992 was associated with an increased risk of pancreatic cancer in men, but not in women.…”

“…However, there are conflicting epidemiological findings on the link between obesity and risk of pancreatic cancer. Several large prospective studies carried out in the U.S.A. have demonstrated that overweight and obese subjects have an increased risk of pancreatic cancer compared with normal weight subjects, [15][16][17] whereas other studies did not observe this association. [18][19][20][21] A meta-analysis conducted in 2003 showed a small positive increase in the risk of pancreatic cancer per unit increase in body mass index (BMI).…”

Exercise therapy across the prostate cancer continuum

“…More than half the studies in this area show an inverse relationship between physical activity and PC, [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] other studies show no association [31][32][33][34][35][36][37][38][39][40][41][42] and four studies even found exercise increased PC risk. [43][44][45][46] Perhaps this uncertainty in the literature can be attributed to the epidemiological nature of the research designs utilized in these studies, which relied upon survey or patient self-reporting to elicit physical activity and/or exercise exposure.…”