Serum Copper and Zinc Levels and Colorectal Cancer in Adults: Findings from the National Health and Nutrition Examination 2011-2016.

Several studies have indicated an association between serum copper and zinc levels and colorectal cancer, but results were controversial. This study assessed the association of serum copper, zinc, and copper/zinc ratio with colorectal cancer in US adults aged 20 years and older through the use of National Health and Nutrition Examination Survey (NHANES) 2011-2016 data. Serum concentrations of copper and zinc were measured using inductively coupled plasma dynamic reaction cell mass spectrometry (ICP-DRC-MS). Odds ratios with 95% confidence intervals (ORs with CIs) were calculated for serum copper, zinc, and copper/zinc ratio by multivariate logistic regression. A total of 4663 participants (2320 males and 2343 females) with 24 colorectal cancer patients were included in the analyses. We did not observe a statistically significant association between serum copper level and colorectal cancer (top vs bottom quartile multivariate OR 1.71; 95% CI, 0.37-7.88; P for trend = 0.429). In addition, serum zinc level was also not significantly associated with colorectal cancer (top vs bottom quartile multivariate OR 0.72; 95% CI, 0.12-4.27; P for trend = 0.346). While in the age- and gender-adjusted model, there seemed to be a trend that participants with higher copper/zinc ratio level had higher odds of colorectal cancer than participants with lower copper/zinc ratio level; no statistically significant association was observed in multivariate-adjusted models. Our findings did not support a significant association between serum copper and zinc level and colorectal cancer risk in the general US population. Furthermore, large longitudinal studies should be needed to confirm these findings.