Cadmium burden and the risk and phenotype of prostate cancer

Abstract

Background: Studies on the association between prostate cancer and cadmium exposure have yielded conflicting results. This study explored cadmium burden on the risk and phenotype of prostate cancer in men with no evident environmental exposure.

Methods: Hospital-based 261 prostate cancer cases and 267 controls with benign diseases were recruited from four hospitals in Taiwan. Demographic, dietary and lifestyle data were collected by standardized questionnaires. Blood cadmium (BCd) and creatinine-adjusted urine cadmium (CAUCd) levels were measured for each participant. Statistical analyses measured the prostate cancer risk associated with BCd and CAUCd separately, controlling for age, smoking and institution. BCd and CAUCd levels within cases were compared in relation to the disease stage and the Gleason score.

Results: High family income, low beef intake, low dairy product consumption and positive family history were independently associated with the prostate carcinogenesis. There was no difference in BCd levels between cases and controls (median, 0.88 versus 0.87 microg/l, p = 0.45). Cases had lower CAUCd levels than controls (median, 0.94 versus 1.40 microg/g creatinine, p = 0.001). However, cases with higher BCd and CAUCd levels tended to be at more advanced stages and to have higher Gleason scores. The prostate cancer cases with Gleason scores of > or = 8 had an odds ratio of 2.89 (95% confidence interval 1.25-6.70), compared with patients with scores of 2-6.

Conclusion: Higher CAUCd and BCd levels may be associated with advanced cancer phenotypes, but there was only a tenuous association between cadmium and prostate cancer.

Figure 1

Comparisons of median blood and urine cadmium levels between prostate cancer cases and controls.

Figure 2

Odds ratio (OR) by stage (C, D vs A+B) and Gleason score (≥ 7 vs. 2-6) of association of prostate cancer with cadmium levels in urine and blood^§ (*p < 0.05; **p for trend = 0.04). ^§ Using the median level of cases as the cutoff value for risk determinations, 0.87 μg/l for blood cadmium and 1.12 μg/g creatinine for urine cadmium.