Abstract 860: Hypertension, diuretics, and antihypertensives in relation to bladder cancer

Abstract

Abstract Background: The role of hypertension and/or antihypertensive medication use on bladder cancer risk is inconclusive. Given the high prevalence of hypertension in the United States, in the present study we investigated the relation between hypertension, antihypertensive drugs, and bladder cancer risk using a population-based case-control study conducted in Los Angeles County, California. Methods: A population-based case-control study of bladder cancer was conducted in Los Angeles County from 1987-1999 and a total of 1586 age-, gender-, race- matched cases and neighborhood controls were included in the analyses. Participants were asked if they were told by a doctor that they had hypertension. They were also asked if they had taken any of the 21 brand names of diuretics and antihypertensive drugs listed in the questionnaire, which represented all the common prescription medications in these respective categories marketed in the US since the 1950s. Regular use was defined as taking a listed brand name drug two or more times a week for one month or longer. We asked regular users the ages at first and last use, duration of use, usual frequency and dosage of use, and the primary reason for such use. Results: A history of hypertension was not related to bladder cancer; however, among hypertensive individuals, there was a significant difference in bladder cancer risk related to the use of diuretics or antihypertensive drugs (P for heterogeneity =0.003). Compared with individuals without hypertension, hypertensive individuals who regularly used diuretics/antihypertensives had a similar risk (odds ratio - OR, 1.05; 95% confidence interval − 95%CI, 0.86-1.29), while untreated hypertensive subjects had a 36% reduction in risk (OR, 0.64; 95% CI, 0.47-0.87). A greater reduction in bladder cancer risk was observed among current smokers (OR, 0.45; 95% CI, 0.28-0.72) and carriers of GSTM1 null (homozygous absence) genotypes (OR, 0.29; 95% CI, 0.16-0.54). Similarly, among smokers with GSTM1 null genotype, levels of 4-aminobiphenyl-hemoglobin adducts were significantly lower among untreated hypertensive individuals (45.7 pg/g Hb) compared to individuals without hypertension (79.8 pg/g Hb) (P = 0.009). Conclusion: Our results suggest that untreated hypertension is associated with a reduced risk of bladder cancer, a finding that was partially supported by our biomarker data. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 860.