Tea Consumption and Risk of Bladder and Kidney Cancers In a Population-based Case-Control Study

Abstract

Recent epidemiologic studies have suggested that tea may be protective against cancers of the urinary tract. The authors examined the association between usual adult tea consumption and risk of bladder and kidney cancers in a population-based case-control study that included 1,452 bladder cancer cases, 406 kidney cancer cases, and 2,434 controls. For bladder cancer, the age- and sex-adjusted odds ratios (OR) (95% confidence intervals (CI)) referent to nonusers of tea were 0.9 (0.7, 1.1) for <1.0 cup/day, 1.0 (0.8, 1.2) for 1.0-2.6 cups/day, and 0.9 (0.7, 1.1) for >2.6 cups/day (cutpoints for users based on the tertile distribution among controls). When more extreme cutpoints were used, persons who consumed >5 cups/day (>90th percentile) had a suggestive decreased risk (OR = 0.7; 95% CI 0.5, 1.0), but there was no evidence of a dose-response relation. In analyses stratified by median total beverage intake (2.6 liters/day), there was an inverse association with tea use among persons who consumed less than the median (OR = 0.5; 95% CI 0.3, 0.8) but no association for persons who consumed at or above the median. In contrast, for kidney cancer, there was no association with tea use. Adjustment for site-specific risk factors did not alter these results. This study offers only minimal support for an inverse association between tea consumption and bladder or kidney cancer risk.

Fluid intake and risk of bladder and other cancers

“…A study of 1452 bladder cancer cases and 2434 population controls from the Iowa Cancer Registry (Bianchi et al, 2000) found no consistent relation between tea intake and bladder cancer (OR, 0.9; 95% CI, 0.7-1.1 for 42.6 cups per day). An inverse relation with tea was apparent for drinkers of 2.6 or more liters of fluid per day.…”

No Association Between Tea Consumption and Risk of Renal Cell Carcinoma: A Meta-analysis of Epidemiological Studies

“…The present study included twelve epidemiological studies (ten case-control (McLaughlin et al, 1984;Goodman et al, 1986;Talamini et al, 1990;Kreiger et al, 1993;Mellemgaard et al, 1994;De Stefani et al, 1998;Bianchi et al, 2000;Hu et al, 2009;Montella et al, 2009;Wang et al, 2012) and two cohort studies (Lee Table 1. Of the ten case-control studies, five were conducted in the USA/Canada (McLaughlin et al, 1984;Goodman et al, 1986;Kreiger et al, 1993;Bianchi et al, 2000;Hu et al, 2009), and the remaining five were conducted in Denmark (Mellemgaard et al, 1994), Italy (Montella et al, 2009), Uruguay (De Stefani et al, 1998), and China (Wang et al, 2012).…”

“…Of the ten case-control studies, five were conducted in the USA/Canada (McLaughlin et al, 1984;Goodman et al, 1986;Kreiger et al, 1993;Bianchi et al, 2000;Hu et al, 2009), and the remaining five were conducted in Denmark (Mellemgaard et al, 1994), Italy (Montella et al, 2009), Uruguay (De Stefani et al, 1998), and China (Wang et al, 2012). Of the two cohort studies, one was conducted in UK (Allen et al, 2011), and the other one was conducted in the USA (Lee et al, 2007).…”

“…Figure 1 is a flow diagram of the procedure used to identify the relevant studies. A total of 12 articles were finally included in the meta-analysis (McLaughlin et al, 1984;Goodman et al, 1986;Talamini et al, 1990;Kreiger et al, 1993;Mellemgaard et al, 1994;De Stefani et al, 1998;Bianchi et al, 2000;Lee et al, 2007;Hu et al, 2009;Montella et al, 2009;Allen et al, 2011;Wang et al, 2012).…”

“…One case-control study reported that a higher consumption of tea significantly increased the risk of renal cell carcinoma (De Stefani et al, 1998), whereas seven case-control studies showed a non-significant positive association (McLaughlin et al, 1984;Goodman et al, 1986;Talamini et al, 1990;Kreiger et al, 1993;Mellemgaard et al, 1994;Bianchi et al, 2000;Hu et al, 2009), and two case-control studies showed a nonsignificant negative association between tea consumption and renal cell carcinoma (Montella et al, 2009;Wang et al, 2012). In contrast, one prospective cohort study reported that higher tea consumption could decrease the risk of renal cell carcinoma (Lee et al, 2007), while the other cohrot study showed that there was no significant association (Allen et al, 2011).…”