Heavy drinking may lead to cancer

Individuals who drink high amounts of alcohol are at increased risks of alcohol-related and all cancers, but quitting or minimizing alcohol intake appears to lower these risks, as reported in a study.

The population-based cohort study used data from the Korean National Health Insurance Service and included 4,513,746 participants (mean age 53.6 years, 51.5 percent men). They completed health screening questionnaires to provide data on alcohol consumption level, which was categorized into none (0 g/d), mild (<15 g/d), moderate (15–29.9 g/d), and heavy (≥30 g/d) drinking.

Researchers assessed changes in the drinking patterns of the participants between 2009 and 2011 and grouped them accordingly, as follows: nondrinker, sustainer, increaser, quitter, and reducer. The primary endpoint was newly diagnosed alcohol-related cancers (eg, cancers of the head and neck, oesophagus, colorectum, liver, larynx, and female breast). The secondary endpoint was all newly diagnosed cancers (except for thyroid cancer).

Over a median follow-up of 6.4 years, cancer had an incidence rate of 7.7 per 1,000 person-years. At each drinking level, the increaser groups were consistently at greater risk of alcohol-related cancers and all cancers compared with the sustainer groups.

The increase in alcohol-related cancer incidence was associated with alcohol dose. The risk increase relative to nondrinking was commensurate with the following alcohol consumption levels: mild (adjusted hazard ratio [aHR], 1.03, 95 percent confidence interval [CI], 1.00–1.06), moderate (aHR, 1.10, 95 percent CI, 1.02–1.18), and heavy (aHR, 1.34, 95 percent CI, 1.23–1.45) drinking levels.

Meanwhile, participants with mild drinking levels who quit drinking were at lower risk of alcohol-related cancer (aHR, 0.96, 95 percent CI, 0.92–0.99) than those who sustained their drinking levels. The risk of all cancer was higher among participants with moderate (aHR, 1.07, 95 percent CI, 1.03–1.12) or heavy (aHR, 1.07, 95 percent CI, 1.02–1.12) drinking levels who quit drinking as compared with those who sustained their levels, but this risk increase disappeared when quitting was sustained.

Finally, compared with sustained heavy drinking, a change from heavy to moderate levels (alcohol-related cancer: aHR, 0.91, 95 percent CI, 0.86–0.97; all cancers: aHR, 0.96, 95 percent CI, 0.92–0.99) or mild levels (alcohol-related cancer: aHR, 0.92, 95 percent CI, 0.86–0.98; all cancers: aHR, 0.92, 95 percent CI, 0.89–0.96) were associated with lower cancer risk.

The findings reinforce the importance of alcohol cessation and reduction for the prevention of cancer.