741,300 new cases of cancer in 2020 are linked to a single substance: alcohol

741,300 new cases of cancer in 2020 are linked to a single substance: alcohol

According to a global study published in The Lancet Oncology , 4% of newly diagnosed cancer cases in 2020 may be associated with alcohol use .

Cancers of the esophagus (189,700 cases), liver (154,700 cases), and breast (98,300 cases) accounted for the largest number of new cases, followed by colorectal cancers and mouth and throat cancers.

More in men than women

The study estimates that men accounted for 77% (568,700 cases) of alcohol-associated cancer cases, compared to women, who accounted for 23% of cases (172,600). Cancers of the esophagus, liver, and breast accounted for the largest number of cases . Globally, then, an estimated 4% (741,300) of all new cancer cases in 2020 were associated with alcohol use.

These cancers have well-established causal links to alcohol use, and the estimates of direct associations with alcohol in the new study are the first of their kind for 2020.

In the new study, the researchers established levels of alcohol consumption per person by country for 2010 (ten years before the cancer case data, to allow for the time it takes for alcohol consumption to affect the possible development of cancer) and then combined them with new cancer cases in 2020 (for the cancers with the strongest evidence for a causal link to alcohol in their main analyzes, 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 liters of alcohol per year per adult) based on alcohol production data, sales and tax data, surveys and opinions on unrecorded alcohol intake, and alcohol consumption data from tourists. Using these, they calculated the amount of alcohol people drank per day.

Moderate consumption was classified as an intake of 0.1 to 20 grams per day , the equivalent of up to two alcoholic beverages; risk consumption of 20 to 60 g per day, between two and six alcoholic drinks per day; and drinking excessively more than 60 g per day, more than six alcoholic drinks per day.

To estimate the effect of alcohol consumption on each included cancer type, the authors used figures describing the risk of that cancer from alcohol consumption (per 10 grams of alcohol consumed per day) from existing scientific reports.