Alcohol drinking and risks of total and site-specific cancers in China: A 10-year prospective study of 0.5 million adults

Abstract

Alcohol drinking is associated with increased risks of several site-specific cancers, but its role in many other cancers remains inconclusive. Evidence is more limited from China, where cancer rates, drinking patterns and alcohol tolerability differ importantly from Western populations. The prospective China Kadoorie Biobank recruited >512 000 adults aged 30 to 79 years from 10 diverse areas during 2004 to 2008, recording alcohol consumption patterns by a standardised questionnaire. Self-reported alcohol consumption was estimated as grams of pure alcohol per week based on beverage type, amount consumed per occasion and drinking frequency. After 10 years of follow-up, 26 961 individuals developed cancer. Cox regression was used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) relating alcohol consumption to incidence of site-specific cancers. Overall, 33% (n = 69 734) of men drank alcohol regularly (ie, ≥weekly) at baseline. Among male current regular drinkers, alcohol intake showed positive dose-response associations with risks of cancers in the oesophagus (655 events; HR = 1.98 [95%CI 1.79-2.18], per 280 g/wk), mouth and throat (236; 1.74 [1.48-2.05]), liver (573; 1.52 [1.31-1.76]), colon-rectum (575; 1.19 [1.00-1.43]), gallbladder (107; 1.60 [1.16-2.22]) and lung (1017; 1.25 [1.10-1.42]), similarly among never- and ever-regular smokers. After adjustment for total alcohol intake, there were greater risks of oesophageal cancer in daily drinkers than nondaily drinkers and of liver cancer when drinking without meals. The risks of oesophageal cancer and lung cancer were greater in men reporting flushing after drinking than not. In this male population, alcohol drinking accounted for 7% of cancer cases. Among women, only 2% drank regularly, with no clear associations between alcohol consumption and cancer risk. Among Chinese men, alcohol drinking is associated with increased risks of cancer at multiple sites, with certain drinking patterns (eg, daily, drinking without meals) and low alcohol tolerance further exacerbating the risks.

Keywords: China; alcohol; cancer; cohort studies; drinking patterns.

FIGURE 1

Associations of alcohol consumption with common cancers in male current regular drinkers. Cox models are stratified by age at risk and study area, and adjusted for education, income, smoking status, physical activity, fresh fruit intake, body mass index and family history of cancer. A‐D, Classified as IARC alcohol‐related cancers. Each solid square represents HR with the area inversely proportional to the “floated” variance of the log HR. The vertical lines indicate group‐specific 95% CIs. The numbers above the error bars are the point estimates for HRs, and the numbers below are the number of events. Alcohol intake is classified based on baseline consumption of <140, 140 to 279, 280 to 419 and ≥420 g/wk. P for trend is estimated by modelling alcohol consumption (g/wk) as a continuous variable among current regular drinkers. CI, confidence interval; HR, hazard ratio; IARC, International Agency for Research on Cancer

FIGURE 2

Associations of alcohol consumption with IARC alcohol‐related cancers and other cancers by smoking status in male current regular drinkers. Conventions are as in Figure 1. IARC, International Agency for Research on Cancer

FIGURE 3

Adjusted HRs for IARC alcohol‐related cancers associated with drinking patterns in male current regular drinkers. Cox models are stratified by age at risk and study area, and adjusted for education, income, smoking status, physical activity, fresh fruit intake, body mass index and family history of cancer, and total weekly intake where indicated. Heavy episodic drinking (HED) is defined as drinking >60 g/session. Conventions are as in Figure 1. CI, confidence interval; HR, hazard ratio; IARC, International Agency for Research on Cancer

FIGURE 4

Joint associations of alcohol consumption and flushing status with oesophageal cancer and lung cancer in male current regular drinkers. Alcohol intake, separately in men reporting flushing and in others reporting no flushing, is classified based on baseline consumption of <140, 140 to 419 and ≥420 g/wk. Conventions are as in Figure 1