Alcohol is estimated to have caused more than 740,000 cancer cases around the world last year, and experts say more needs to be done to highlight the link.
There is strong evidence that alcohol consumption can cause various cancers including those of the breast, liver, colon, rectum, oropharynx, larynx and oesophagus. Research suggests that even low levels of drinking can increase the risk.
However, public awareness appears low: one UK survey, in 2018, found only one in 10 people were aware that alcohol could cause cancer.
Researchers say that needs to change. They revealed that in 2020 an estimated 741,300 cases of cancer, globally, were caused by alcohol. They suggested that alcohol labels should have cancer warnings, that there could be higher taxes on alcohol and that marketing of drinks could be reduced.
Harriet Rumgay, of the International Agency for Research on Cancer, in France, and a co-author of the study, said alcohol caused a substantial burden of cancer globally, and this was shown even at lower levels of drinking.
“Alcohol’s impact on cancer is often unknown or overlooked, so we need increased public awareness of the link between alcohol and cancer, and policies to decrease overall alcohol consumption to prevent the burden of cancers and other diseases attributable to alcohol,” Rumgay said.
Writing in The Lancet Oncology, the team describe how they made their calculations using existing alcohol consumption estimates for 2010, based on figures including tax and sales data, as well as other data such as risk estimates for cancers known to be linked to alcohol.
“There is a delay between alcohol consumption and possible cancer development, so it is necessary to factor in a latency period between the year of alcohol exposure data and the year of cancer diagnosis,” said Rumgay.
The researchers combined these figures with existing estimates of new cancer cases expected for 2020 – based on records from previous years and hence not affected by disruptions due to the Covid pandemic – to estimate the number of cases probably caused by drinking.
The results suggested alcohol consumption was behind an estimated 568,700 cancer cases in men and 172,600 cases in women in 2020, with the majority of the cancer cases involving cancers of the oesophagus, liver and breast. However, when looking at the causes of each cancer type separately, the proportion of cases deemed caused by alcohol was highest for cancers of the oesophagus, pharynx, and lip and oral cavity.
While most alcohol-caused cancer cases were linked to heavy or “risky” drinking, even moderate or low levels of alcohol consumption were estimated to have caused cases. The data indicated that drinking up to 10g of alcohol a day – equivalent to a half pint or small glass of wine – contributed somewhere between 35,400 and 145,800 cases globally in 2020.
The findings differed by region. The proportion of cancer cases estimated to be caused by alcohol was lowest in north Africa and west Asia but highest in east Asia and central and eastern Europe. There was some variation between men and women. In the UK an estimated 4% of cancer cases in 2020, about 16,800 cases, were linked to alcohol consumption.
Rumgay said: “It would be very interesting to estimate cancer deaths due to alcohol, which is a follow-up step from the analysis that we have done here.”
The figures are likely to be underestimates, not least because they do not take into account former drinking and only include cancers where there is strong evidence of alcohol being the cause. Other complications include the risk estimates not being specific to particular populations.
Michelle Mitchell, Cancer Research UK’s chief executive, said the research demonstrated that there was still lots of work to do to prevent alcohol-related cancers.
She said: “There’s strong evidence that drinking alcohol can cause seven types of cancer, and the more someone drinks the greater their risk. There’s no safe level of drinking, but whatever your drinking habits cutting down can reduce your risk of cancer. Minimum unit pricing for alcohol, introduced in Scotland and Wales and shortly in Northern Ireland, would be a positive step for England and we urge the government to introduce it here.”
