Serum lipids and endometrial cancer risk: results from the HUNT-II study

Obesity is a major risk factor for endometrial cancer. Still, the association of obesity-related metabolic factors, such as serum lipids and lipoprotein levels, is unclear. We prospectively examined the association of serum levels of triglycerides, total cholesterol, low-density lipoprotein cholesterol, non-high-density lipoprotein (non-HDL), and HDL cholesterol with endometrial cancer risk among 31,473 women. During 9 years of follow-up, 100 cases of endometrial cancer were identified by linkage to the Cancer Registry of Norway. There was a positive association of serum triglyceride levels with endometrial cancer risk. Comparing the highest to the lowest quartile of triglycerides, the age-adjusted hazard ratio was 2.34 (95% CI: 1.04-5.28), and further adjustment for body mass index attenuated the association (hazard ratio 1.79, 95% CI: 0.79-4.05). For total serum cholesterol, low-density lipoprotein cholesterol and HDL cholesterol there were no associations with endometrial cancer risk, either without or after adjustment for body mass index. Serum triglyceride levels were positively associated with the risk of endometrial cancer, and some of the association seems to be attributable to obesity. Apart from higher estrogen levels produced in adipose tissue, mechanisms more specifically related to triglycerides may also be involved in endometrial cancer. Further prospective studies on this subject are needed to better understand the association of blood lipids with endometrial cancer risk.