About half of colorectal tumors express elevated levels of COX-2, the key enzyme responsible for generating prostaglandins that promote cancer development. Prostaglandin E2 (PGE2) is likely the primary mediator of most of COX-2’s tumor-promoting effects, and the PGE2 metabolite, PGE-M, can be measured noninvasively in urine.
To assess the utility of PGE-M as a biomarker of colon cancer risk, Martha Shrubsole, assistant professor of medicine, and colleagues compared levels of PGE-M in the urine of patients with colorectal adenomas (precancerous lesions) versus controls.
In the February issue of Cancer Prevention Research, the investigators report that high levels of PGE-M in the urine was associated with increased risk of advanced or multiple adenomas, particularly among women. However, levels of PGE-M were not increased in patients with a less aggressive type of adenoma (single small tubular adenomas), suggesting that measuring urinary PGE-M may offer a way to distinguish which colon adenomas are more clinically significant.
The research was supported by grants from the National Cancer Institute of the National Institutes of Health.
