The results show, for instance, that obesity increases the risk of colon cancer in both men and women but increases the risk of rectal and liver cancers in men only.
“Our data suggest that obesity represents a decisive risk factor for the development of colon, rectal, and liver cancer, partly in a sex-dependent manner,” Sven H. Loosen, MD, of Heinrich Heine University, Düsseldorf, Germany, and colleagues write.
The study was published online Feb. 13 in Cancers.
Among 287,357 adults from the Disease Analyzers database, Dr. Loosen and colleagues compared the development of GI cancers in preobese (body mass index, 25-30 kg/m2) and obese (BMI, 30 mg/m2 or greater) individuals to that of individuals of normal weight (BMI, 18.5-25 kg/m2).
For colon cancer, the authors observed a stepwise increase in the proportion of diagnoses, from 0.5% and 0.64% in normal weight women and men, respectively, to 0.71% and 0.91% in obese women and men, respectively. In multivariable regression models, that translated to a significantly increased risk of colon cancer in obese women (odds ratio, 1.23; 95% confidence interval, 1.03-1.48) and obese men (OR, 1.43; 95% CI, 1.17-1.74).
However, multivariable regression models showed that associations between obesity and rectal and liver cancers occurred only in men (OR, 1.36 and 1.79, respectively).
Notably, the authors also observed a negative association between pre-obesity and stomach cancer in men (OR, 0.65) and obesity and pancreatic cancer in women (OR, 0.61).
In other words, women and men with excess body fat may be “protected” from developing these conditions, “highlighting the complexity of the association between BMI and cancer in the different sexes,” the authors write.
These findings could have implications for prevention and lifestyle programs, the authors say.
“Since pre-obesity and obesity are modifiable risk factors, the current results may help to establish appropriate prevention and lifestyle programs to reduce the high morbidity and mortality of GI tumors in the future,” they conclude. They suggest that some “overweight patients might be presented in a specific interdisciplinary ‘metabolic board’ comprising oncologists and physicians specialized in preventive medicine.”
No specific funding related to this study has been disclosed. The authors have disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.