Alcohol is estimated to have caused more than 740,000 cancer cases around the world last year, a global study suggested. The findings of the study appeared in the journal ‘The Lancet Oncology’. According to the study, four per cent of newly diagnosed cancer cases in 2020 may be associated with drinking alcohol. The authors called for greater public awareness of the link between alcohol and cancers and increased government interventions to reduce alcohol consumption in worst-affected regions.
The study estimated that men accounted for 77 per cent (568,700 cases) of alcohol-associated cancer cases, compared with women, who accounted for 23 per cent of cases (172,600). Cancers of the oesophagus, liver, and breast accounted for the largest number of cases. Based on data from previous years, it is estimated that in 2020, there were more than 6.3 million cases of mouth, pharynx, voice box (larynx), oesophageal, colon, rectum, liver, and breast cancer. These cancers have well-established causal links to alcohol consumption, and the estimates of the direct associations with alcohol in the new study are the first of their kind for 2020.
Disruptions to health care and cancer services across the world due to the COVID-19 pandemic are likely to have affected diagnosis rates for that year and may have led to an underestimation of new cancer cases in the recorded data. However, this would not be reflected in this study as estimates for 2020 were based on recorded data from previous years.
Alcohol consumption has been shown to cause DNA damage through increased production of harmful chemicals in the body, and affect hormone production, which can contribute to cancer development.
Alcohol can also worsen the cancer-causing effects of other substances, such as tobacco. “We urgently need to raise awareness about the link between alcohol consumption and cancer risk among policy makers and the general public. Public health strategies, such as reduced alcohol availability, labelling alcohol products with a health warning, and marketing bans could reduce rates of alcohol-driven cancer. Tax and pricing policies that have led to decreased alcohol intake in Europe, including increased excise taxes and minimum unit pricing, could also be implemented in other world regions. Local context is essential for successful policy around alcohol consumption and will be key to reducing cancer cases linked to drinking,” said Ms Harriet Rumgay of the International Agency for Research on Cancer (IARC), France.
In the new study, researchers established levels of alcohol intake per person per country for 2010 (ten years prior to the cancer case data, to allow for the time it takes for alcohol intake to affect possible cancer development) then combined them with estimated new cancer cases in 2020 (for the cancer types with the strongest evidence of a causal link to alcohol in their main analyses, plus all cancers combined except non-melanoma skin cancer) to estimate the number of alcohol-associated cancers in each country.
The authors used estimates for alcohol intake (in litres of alcohol per year per adult) based on alcohol production data, tax and sales data, surveys and opinion on unrecorded alcohol intake, and tourist alcohol consumption data. Using these they estimated how much alcohol people drank per day.
Moderate drinking was classed as intake of 0*1 to 20 grams per day, the equivalent of up to two alcoholic drinks; risky drinking as 20 to 60 g per day, between two and six alcoholic drinks per day; and heavy drinking as more than 60 g per day, more than six alcoholic drinks per day.
To estimate the effect of alcohol consumption on each cancer type included, the authors used figures outlining the risk of that cancer from alcohol consumption (per 10 grams of alcohol consumed per day) from existing scientific reports.
