According to a recent article published in the Journal of the National Cancer Institute, elevated levels of C-peptide in blood samples is associated with an increased risk of developing colorectal cancer in men.
Colorectal cancer is the second leading cause of cancer deaths annually in the United States. If colorectal cancer is detected early, prior to spread of cancer, cure rates remain high. However, once the cancer has spread from the large intestine, cure rates fall dramatically. Due to the high mortality rate from colorectal cancer in the U.S., researchers are evaluating “markers” in an attempt to identify patients who may be at a high risk of developing the disease. Individuals who are deemed to be high risk may then undergo appropriate screening measures to allow the early detection of cancer, in order to treat the disease when it is most curable.
C-peptide found in the blood (plasma C-peptide) is an indicator of insulin production in the body. Since high levels of insulin in the blood appears to have an association with the development of colorectal cancer, researchers are evaluating risk factors such as diabetes type 2, exercise, insulin levels, insulin resistance factors and diet. Researchers from Boston and Canada recently conducted a study to determine if an association existed between plasma C-peptide levels and the development of colorectal cancer. Data was obtained from individuals who participated in the Physicians’ Health Study between 1982 and 1984 who were cancer free at that time. Plasma samples with levels of C-peptide were obtained from nearly 472 men – 176 of whom subsequently developed colorectal cancer, and 294 who had not developed cancer, but were matched with the group of men who did develop cancer in terms of smoking status and age. Men with elevated levels of plasma C-peptide were at a significantly higher risk of developing colorectal cancer than those without elevated plasma C-peptide levels. Men with the most elevated C-peptide levels had approximately 3 times the risk of developing colorectal cancer compared to those with the lowest levels. The association between plasma C-peptide levels and the development of colorectal cancer was not changed even when factors such as body mass index (BMI), vigorous exercise or insulin-resistance related factors were included in the assessment.
The researchers concluded that elevated plasma C-peptide levels appear to be strongly associated with an increased risk of developing colorectal cancer in men. These results need to be confirmed in larger clinical studies; however, the implications may help to predict those men who should be screened more diligently for colorectal cancer. Men who are at an increased risk of developing colorectal cancer (i.e. a family history of the disease) may wish to speak with their physician about the risks and benefits of participating in a clinical trial further evaluating plasma C-peptide levels or other markers that may help predict the risk of colorectal cancer. Two sources of information regarding ongoing clinical trials include the National Cancer Institute (cancer.gov) and www.cancerconsultants.com. Personalized clinical trial searches are also performed on behalf of cancerconsultants.com.
Reference: Ma J, Giovannucci E, Pollak M, et al. A prospective study of plasma C-peptide and colorectal cancer risk in men. Journal of the National Cancer Institute. 2004; 96: 546-553.