Data from a large-scale population-based case control study indicated that excessive weight could have a notably higher odds ratio of CRC risk than previously identified in epidemiologic studies.
A cumulative lifetime of excess weight has been identified as a potential factor in colorectal cancer (CRC) risk based on results from a case-control study vs analyses of body mass index (BMI) from a single time point and reported in JAMA Oncology.
Investigators observed an association between weighted number of years lived with overweight or obesity (WYO) and CRC risk. Notably, the odds ratio (OR) increased from 1.25 (95% CI, 1.09-1.44) to 2.54 (95% CI, 2.24-2.89) from the first to the fourth quartile of WYO vs those with a normal weight range. With each standard deviation (SD) increment of WYO, there was an increased risk of CRC by 55% (adjusted OR, 1.55; 95% CI, 1.46-1.64).
A total of 5822 patients with CRC and 6568 controls wanted to participate in the study, of whom, 5635 patients with CRC and 4515 controls gave complete information on height and weight and were included in the analysis. Patients with CRC had a median age of 68.4 years, and 3366 were men. In the comparator arm, patients had a mean age of 68.5 years and 2759 were men. Additional characteristics that were considered between the CRC and control groups, respectively, were current and former smoking status (55.1% vs 49.1%), obesity (23.0% vs 16.1%), diabetes (19.0% vs 13.4%), and lower education levels (17.5% vs 24.3%).
Investigators identified that patients with CRC vs the control group were more likely to have a family history of CRC (14.5% vs 10.8%), and less likely to undergo colonoscopies (26.7% vs 60.5%), use nonsteroidal anti-inflammatory drugs (26.3% vs 33.4%), and use of statins (16.5% vs 21.2%).
Mean BMI increase with age both in the CRC and the control groups, reaching a maximum age of 70 years. A significantly higher BMI was observed at decennial ages in the CRC group (26.6) compared with the control group (25.8). The prevalence of overweight and obesity status were higher in the CRC group than the controls at each age, including 45.7% vs 43.3% for overweight and 17.1% vs 11.4% for obesity at 50 years in each group, respectively.
At ages 20 years and 30 years, the multivariable adjusted OR for CRC risk per SD increase of BMI was 1.19 (95% CI, 1.14-1.25), and the maximum OR was 1.26 (95% CI, 1.20-1.33) at 60 years. Moreover, at 10 years before enrollment it was 1.27 (95% CI, 1.21-1.33). Those across all ages except for 80 years had a dose response association that included a 16% to 36% increased odds of CRC for the overweight group, and a 64% to 106% increase in odds for the obesity group, according to age and sex adjusted analyses.
During each SD increase of WYO there was an adjusted multivariable OR for risk of CRC of 1.55 (95% CI, 1.46-1.64); this was a higher OR for excess BMI at a single time point from 1.04 (95% CI, 0.93-1.16) at age 80 to 1.27 (95% CI, 1.16-1.39) at age 20 per SD of excessive BMI.
Li X, Jansen L, Chang-Claude J, Hoffmeister M, Brenner H. Risk of colorectal cancer associated with lifetime excess weight. JAMA Oncol. Published Online March 17, 2022. doi:10.1001/jamaoncol.2022.0064