There is convincing evidence that excess body weight is associated with increased risk for late onset (> 50 years of age) colorectal cancer (CRC)
Oncotarget published "High-fat diet-fed ovariectomized mice are susceptible to accelerated subcutaneous tumor growth potentially through adipose tissue inflammation, local insulin-like growth factor release, and tumor associated macrophages" which reported that the association between obesity and colorectal cancer (CRC) risk has been well established. This relationship appears to be more significant in men than in women, which may be attributable to sex hormones - controlled animal studies to substantiate these claims and the mechanisms involved are lacking. MC38 murine colon adenocarcinoma cells were injected subcutaneously into high-fat diet fed male, female and ovariectomized female C57BL/6 mice.
HFD OVX mice exhibited the most significant tumor growth compared to HFD male and female mice and this was associated with increased subcutaneous adipose tissue.
Further, the subcutaneous adipose tissue depots within HFD OVX mice exhibited more severe macrophage associated inflammation compared to female, but not male mice.
Conditioned media from subcutaneous adipose tissue of HFD OVX contained higher IGF-1 levels compared to male, but not female mice.
Finally, HFD OVX mice had increased M2-like gene expression in their tumor-associated macrophages compared to female mice.
Dr. Angela Murphy from The University of South Carolina said, "There is convincing evidence that excess body weight is associated with increased risk for late onset (> 50 years of age) colorectal cancer (CRC)."
