Alcohol consumption was associated with 62,100 or 5 per cent of newly diagnosed cancer cases last year in India, according to a study published in The Lancet Oncology journal which shows alcohol use is on the rise in the country.
Globally, the researchers found that more than 7,40,000 or four per cent of new cancer cases in 2020 may be attributed to alcohol drinking.
The study estimates 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 shows 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.
"Trends suggest that although there is a decrease in alcohol consumption per person in many European countries, alcohol use is on the rise in Asian countries such as China and India, and in sub-Saharan Africa," said Harriet Rumgay of the International Agency for Research on Cancer (IARC), France.
"In addition, there is evidence that the COVID-19 pandemic has increased rates of drinking in some countries," Rumgay said.
The researchers call for greater public awareness of the link between alcohol and cancers and increased government interventions to reduce its consumption in worst-affected regions.
The study highlights the contribution of even relatively low levels of drinking to rates of cancer, which is concerning, but also suggests that small changes to public drinking behaviour could positively impact future cancer rates.
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, according to the researchers.
Alcohol can also worsen the cancer-causing effects of other substances, such as tobacco, they said.
In the new study, researchers established levels of alcohol intake per person per country for 2010, to allow for the time it takes for alcohol intake to affect possible cancer development.
They then combined them with new cancer cases in 2020 to estimate the number of alcohol-associated cancers in each country.
Moderate drinking was classed as intake of up to two alcoholic drinks, risky drinking as between two and six alcoholic drinks per day, and heavy drinking as more than six alcoholic drinks per day.
Globally, an estimated 4 per cent (741,300) of all new cases of cancer in 2020 were associated with alcohol consumption, the researchers said.
The study found that risky drinking and heavy drinking led to the largest proportion of cancer cases at 39 per cent (291,800 cases) and 47 per cent (346,400 cases) respectively.
However, moderate drinking was also found to be problematic, with estimates that this level of drinking accounted for 14 per cent (103,100 cases) of the total of alcohol-caused cases.
Eastern Asia and Central and Eastern Europe regions had the highest proportions of cancer cases that could be associated with alcohol at 6 per cent, with the lowest proportions found in Northern Africa and Western Asia, both below 1 per cent.
At a country level, the proportions of cancer cases associated with alcohol were estimated to be highest in Mongolia (10 per cent) and lowest in Kuwait (estimated at 0 per cent).
India had an estimated 5 per cent (62,100) of cancer cases linked to alcohol, while China 6 per cent (282,300), Germany 4 per cent (21,500 cases) and France had 5 per cent (20,000 cases).
The United Kingdom had an estimated 4 per cent of cancer cases linked to alcohol (16,800), with the United States at 3 per cent (52,700), and Brazil at 4 per cent (20,500 cases).
"We urgently need to raise awareness about the link between alcohol consumption and cancer risk among policy makers and the general public," said Rumgay.
The researchers noted that 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, they added.
