Alcohol and Prostate Cancer in the NHANES I Epidemiologic Follow-Up Study

Abstract

PURPOSE: We prospectively investigated the association between alcohol consumption and prostate cancer in the Epidemiologic Followup Study (NHEFS) of the first National Health and Nutrition Examination Survey (NHANES I).

METHODS: There were two cohorts: 1) Cohort I, followed from baseline (1971–75) through 1992, included 5766 men ages 25–74 years (median follow-up = 17 years); and 2) Cohort II, followed from the first follow-up round for Cohort I (1982–84) through 1992, included the 3868 men in Cohort I free of prostate cancer in 1982–84 (median follow-up = 9 years). Alcohol consumption was assessed at baseline as usual consumption, and at follow-up as usual consumption and as distant past consumption at the ages of 25, 35, 45, and 55.

RESULTS: There were 252 incident cases of prostate cancer. Consistent with most previous studies, we found no significant associations between usual total alcohol consumption and prostate cancer in Cohorts I or II [p = non significant (NS)], except for a significant inverse association at the heaviest level of drinking in Cohort II [relative risk (RR) = 0.23, 95% confidence interval (CI) = 0.06–0.95]. Further study of heavy drinkers in Cohort II revealed significant inverse associations between distant past heavy drinking (defined as > 25 drinks/week) and prostate cancer at age 25 (RR = 0.20, 95% CI = 0.06–0.63), age 35 (RR = 0.30, 95% CI = 0.12–0.77), and age 45 (RR = 0.39, 95% CI = 0.17–0.93), but not at age 55 (RR = 0.43, 95% CI = 0.17–1.10).

CONCLUSIONS: These results suggest that it may be important to consider distant past alcohol consumption in etiologic studies of prostate cancer. However, our results were based on small numbers of cases who were heavy drinkers and require replication.

Introduction

Despite the fact that prostate cancer is one of the most common cancers among men in the United States (1), few risk factors are well-established other than age, race, and family history (2). Therefore, the identification of additional risk factors, particularly modifiable risk factors, is of considerable interest.

Although alcohol consumption has been proposed as a risk factor for prostate cancer incidence, most case-control studies 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, and cohort studies in general populations 21, 23, 24, 25, 26, 27, 28, 29, 30 have not reported significant associations. There are exceptions. Two population-based cohort studies reported increased risk of prostate cancer among alcoholics; one by Tonnesen et al. in Denmark (31), and the other by Adami et al. in Sweden (32). A cohort study by Hirayama in Japan (33) also reported increased risk. Two case-control studies reported increased risk of prostate cancer in drinkers; one by De Stefani et al. in a study in Uruguay (34), and the other by Hayes et al. in a large, population-based study in the United States (35). A third case-control study by Jackson in Washington, D.C. (36) reported an inverse association.

The majority of studies on alcohol and prostate cancer have assessed usual alcohol consumption, generally over the previous year (21). Yet, clinical and epidemiologic evidence suggest that prostate carcinogenesis may span decades (37), implying the possible etiologic relevance of long-term alcohol consumption.

The purpose of this study was twofold: to examine the association between usual alcohol consumption and prostate cancer; and to examine the association between distant past alcohol consumption and prostate cancer. Prospective cohort data from 5766 male participants in the follow-up study of the first National Health and Nutrition Examination Survey of the United States (NHANES I), the Nutrition and Health Examination Follow-Up Study (NHEFS), were used to study these associations.