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.