No Association of Plasma Levels of Adiponectin and c-peptide with Risk of Aggressive Prostate Cancer in the Cancer Prevention Study II Nutrition Cohort

Abstract

Background: Obesity is associated with a higher risk of aggressive prostate cancer and alters circulating levels of insulin and adiponectin, two hormones that influence biologic processes implicated in carcinogenesis. Results of some studies showed associations of circulating levels of adiponectin, insulin, and c-peptide (a marker of insulin secretion) with aggressive prostate cancer, but the size of these studies was limited.Methods: A nested case-control study of 272 aggressive prostate cancer cases [Gleason score !7 (4þ3) or T3-T4] and 272 age-and race-matched controls from the Cancer Prevention Study II Nutrition Cohort was conducted to determine the associations of prediagnostic plasma levels of c-peptide and adiponectin with risk of aggressive prostate cancer.Results: Neither circulating adiponectin nor c-peptide was associated with risk of aggressive prostate cancer. In analyses of the highest-risk aggressive prostate cancer (Gleason score !8 or T3-T4), the highest quartile of c-peptide, compared with the lowest, was associated with an OR of 1.41 [95% confidence interval (CI), 0.72-2.78].Conclusions: Our findings provide no support for the hypothesis that adiponectin is associated with risk of aggressive prostate cancer but a possible association of high levels of c-peptide with particularly high-risk prostate cancer cannot be ruled out.Impact: These results indicate that changes in circulating levels of adiponectin and c-peptide do not play an important role in risk of aggressive prostate cancer. Cancer Epidemiol Biomarkers Prev; 23(5); 890-2. Ó2014 AACR.

Evolving role of adiponectin in cancer-controversies and update

“…Furthermore, reduced APN levels were associated with tumor stage in obese and overweight men, but not in normal weight men or overall in all men 135 . Other studies have also found no significant association between APN levels and PrC risk 136,137 .…”

The Epidemiology of Prostate Cancer

“…In a pro-spective cohort with prediagnostic bloods, men who had high-circulating levels of C-peptide, a marker of insulin secretion, had an increased cancer-specific mortality (Ma et al 2008). However, this association was not confirmed in two prospective studies for risk of aggressive disease (Ma et al 2008;Stevens et al 2014).…”

Obesity and Diabetes: The Increased Risk of Cancer and Cancer-Related Mortality

“…A recent meta-analysis did not find an increased risk of breast cancer in women with elevated serum insulin or C-peptide levels after adjusting for BMI, suggesting that insulin and C-peptide levels are not independent of BMI (9). In prostate cancer, some studies, including the Health Professionals Follow-Up Study and the CPS II Nutrition cohort, have reported no clear correlation between circulating C-peptide and either prostate cancer risk, or mortality, or in the risk of developing aggressive prostate cancer (107,124,177). However, the Physicians Health Study reported that obese men with elevated C-peptide levels were four times more likely to die from prostate cancer than men with normal C-peptide levels (124).…”