Overweight and obesity at any time during adulthood are associated with an increased risk for colorectal cancer (CRC), according to a study in JAMA Oncology.

Researchers sought to determine a measure of cumulative lifetime exposure to excess weight and to assess the strength of its association with the risk for CRC.

Data were obtained from the DACHS study, an ongoing, population-based, case-control study conducted since 2003. Patients aged 30 years and older with a first diagnosis of CRC were enrolled from more than 20 hospitals that provided CRC surgery in Germany from 2003 to 2017.

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The investigators compared the prevalence of overweight and obesity at various ages (20 years to the highest considered decennial age) between patients with CRC and control individuals according to body mass index (BMI). Researchers calculated the mean BMI for each decennial age using the height and reported weight of patients.

Age and sex were comparable between patients with CRC (n=5635; mean age, 68.4±10.9 years; 59.7% men) and the control group (n=4515; mean age, 68.5±10.6 years; 61.1% men).

Mean BMI increased with age for patients with CRC and control individuals, and it reached a maximum at age 70 years (patients, 27.5; controls, 26.8). Compared with control individuals, patients with CRC had a significantly higher BMI at each decennial age. At each age, the prevalence of overweight and obesity was significantly higher in patients with CRC vs control individuals.

Multivariable adjusted odds ratios (ORs) for CRC risk per standard deviation (SD) increase of BMI were 1.19 (95% CI, 1.14-1.25) for those aged 20 and 30 years and reached a maximum of 1.26 (95% CI, 1.20-1.33) at age 60 years and 1.27 (95% CI, 1.21-1.33), approximately 10 years (range, 5-14 years) before study enrollment.

For each SD increment of weighted number of years lived with overweight or obesity (WYOs), the multivariable-adjusted OR for CRC risk was 1.55 (95% CI, 1.46-1.64), which was higher compared with the corresponding ORs for excess BMI (eBMI) at a single point of time, from 1.04 (95% CI, 0.93-1.16) at age 80 years to 1.27 (95% CI, 1.16-1.39) at age 20 years per SD of eBMI.

A dose-response association was also found with multivariable-adjusted ORs for WYO quartiles 1 to 4 vs those who were never overweight (WYO, 0).

Study limitations include potential selection bias, which could have resulted in some overestimation of the role of excess weight in CRC risk.

“Excess weight may have substantially higher ORs associated with CRC risk than previously disclosed by epidemiologic studies that had mostly considered weight at a single point of time,” the study authors concluded. “Use of the concept of WYOs in further studies, including prospective cohort studies, may help to more fully disclose the association of excess weight not only with CRC but also with other cancers and diseases.”


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

This article originally appeared on Gastroenterology Advisor