Yeli Wang1, Tazeen H Jafar1,2, Aizhen Jin1, Jian-Min Yuan3,4, Woon-Puay Koh1,5. 1. Health Services and Systems Research, Duke-NUS Medical School, Singapore. 2. Health Services Research Centre, SingHealth, Singapore. 3. Division of Cancer Control and Population Sciences, UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, Pennsylvania, USA. 4. Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA. 5. Saw Swee Hock School of Public Health, National University of Singapore, Singapore.
Abstract
Background: Epidemiological studies have demonstrated separately that patients with kidney stone may have higher dietary intake of zinc and higher risk of developing kidney cancer. We prospectively assessed the associations of dietary zinc and other trace elements with kidney cancer risk for the first time. Methods: We used data from the prospective Singapore Chinese Health Study that recruited 63,257 adult Chinese residing in Singapore between 1993 and 1998. A validated food frequency questionnaire and the Singapore Food Composition Database was used to compute the values of intake for zinc, copper and manganese. We identified incident cancer cases via linkage with nationwide cancer registry, and used Cox proportional hazard models to compute hazard ratio (HR) and 95% confidence interval (CI) for the association with kidney cancer risk. Results: There were 229 incident kidney cancer cases after median follow-up of 20.1 years. Dietary zinc intake was positively associated with higher kidney cancer risk; the HR comparing the extreme quartiles of zinc intake was 1.74 (95% CI: 1.02-2.97; P-trend = 0.033). Conversely, intakes of copper and manganese were not associated with kidney cancer risk.Conclusions: The positive association between dietary zinc and risk of kidney cancer suggests that zinc may be implicated in renal carcinogenesis.
Background: Epidemiological studies have demonstrated separately that patients with kidney stone may have higher dietary intake of zinc and higher risk of developing kidney cancer. We prospectively assessed the associations of dietary zinc and other trace elements with kidney cancer risk for the first time. Methods: We used data from the prospective Singapore Chinese Health Study that recruited 63,257 adult Chinese residing in Singapore between 1993 and 1998. A validated food frequency questionnaire and the Singapore Food Composition Database was used to compute the values of intake for zinc, copper and manganese. We identified incident cancer cases via linkage with nationwide cancer registry, and used Cox proportional hazard models to compute hazard ratio (HR) and 95% confidence interval (CI) for the association with kidney cancer risk. Results: There were 229 incident kidney cancer cases after median follow-up of 20.1 years. Dietary zinc intake was positively associated with higher kidney cancer risk; the HR comparing the extreme quartiles of zinc intake was 1.74 (95% CI: 1.02-2.97; P-trend = 0.033). Conversely, intakes of copper and manganese were not associated with kidney cancer risk.Conclusions: The positive association between dietary zinc and risk of kidney cancer suggests that zinc may be implicated in renal carcinogenesis.