Obesity, Inflammation in Adolescence May Up Colon Cancer Risk

A 35-year study of males in Sweden found a link between obesity and inflammation during adolescence and a risk for colorectal cancer in adulthood. Obese males, 16 to 20 years of age, were two times as likely to be diagnosed with colorectal cancer during adulthood, compared with their healthy-weight counterparts. The study also found that teens who had high levels of inflammation had a 63% increased risk of colorectal cancer in adulthood. The association between inflammation and colorectal cancer risk was independent of obesity.

The results were presented by study author Elizabeth Kantor, PhD, a postdoctoral research fellow in the department of epidemiology at the Harvard School of Public Health in Boston, at the 13th Annual American Association for Cancer Research (AACR) International Conference on Frontiers in Cancer Prevention Research in New Orleans.

While inflammation and obesity in adulthood have been previously linked to colorectal cancer, there is relatively little information on how obesity and inflammation earlier in life may affect risk of colorectal cancer, Kantor told Cancer Network.

The study suggested that obesity and inflammation earlier in life may set the stage for cancer later in life and may help guide prevention strategies. But, more research is still needed to fully understand the links between weight, inflammation, age, and colorectal cancer risk.

Kantor and colleagues analyzed data from a large cohort of 239,464 Swedish male adolescents who underwent physical exams for military conscription between 1969 and 1976. Their height, weight, and blood samples were collected to measure inflammation as part of the conscription registry. The researchers were then able to link this data with data from Sweden’s cancer registry to see which of the men developed colorectal cancer. As of January 2010, a total of 885 men in the cohort had developed colorectal cancer.

One limitation of the study was that other factors related to colorectal cancer risk, such as diet and genetics, were not available through this dataset. Additionally, obesity is relatively uncommon in this cohort and may represent something different than the characteristics of obesity in the present day, Kantor noted.

Prospective studies on the association between obesity, inflammation, and colorectal cancer risk are still needed in a broader population of subjects to understand whether and how these factors are linked. Particularly, it is not clear whether individuals who remain overweight or obese from adolescence into adulthood have a higher risk of colorectal cancer compared with those who were obese as adolescents but who have a normal weight as adults.