Authors call for greater public awareness of link between alcohol and cancers.
A new study led by scientists from the International Agency for Research on Cancer (IARC) shows that an estimated 741,000 new cases of cancer in 2020 were associated with alcohol consumption globally.
These latest data, published July 14 in The Lancet Oncology, indicate that although risky and heavy drinking patterns (more than two alcoholic drinks per day) represented the largest cancer burden (86% of the total alcohol-attributable cases), light to moderate drinking (up to two alcoholic drinks per day) represented 1 in 7 alcohol-attributable cases and accounted for more than 100,000 new cancer cases worldwide.
“Alcohol consumption causes a substantial burden of cancer globally,” said Dr. Isabelle Soerjomataram, deputy head of the Cancer Surveillance Branch at IARC. “Yet the impact on cancers is often unknown or overlooked. This highlights the need for implementation of effective policy and interventions to increase public awareness of the link between alcohol consumption and cancer risk, and to decrease overall alcohol consumption to prevent the burden of alcohol-attributable cancers.”
Our own Farhad Islami, MD, PhD, scientific director, Cancer Disparity Research (pictured here), was one of the 10 researchers that were involved in the design and conduct of this study. He noted that "the results for the U.S. are consistent with findings of our previous studies at the ACS and further support prioritizing federal- and state-level cancer prevention and control efforts to reduce alcohol consumption and the burden of alcohol-related cancers.”
All the results of the IARC study are available on the new Cancers Attributable to Alcohol website, which is part of the Cancer Causes subsite of the IARC Global Cancer Observatory. The database has user-friendly facilities to produce maps and explore visualizations of the global burden of cancer attributable to alcohol consumption by sex, cancer site, and country or world region.
Here are some key findings:
- Eastern Asia and Central and Eastern Europe regions had the highest proportions of cancer cases that could be associated with alcohol at 6%, with the lowest proportions found in Northern Africa and Western Asia, both below 1%.
- The study estimates that men accounted for 77% (568,700 cases) of alcohol-associated cancer cases, compared with women, who accounted for 23% of cases (172,600).
- 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 cancers of the mouth and throat.
- Among women, the largest proportions of cancer cases that were attributed to alcohol were estimated to be in the regions of Central and Eastern Europe (3%, 21,500 cases), and Australia and New Zealand (3%, 2,600 cases). Amongst men, the largest proportions of cancer cases linked to alcohol were found in Eastern Asia (9%, 275,900 cases) and Central and Eastern Europe (8%, 49,900 cases).
- At a country level, the proportions of cancer cases associated with alcohol were estimated to be highest in Mongolia (10%, 560 cases) and lowest in Kuwait (estimated at 0%, less than 5 cases). The UK had an estimated 4% of cancer cases linked to alcohol (16,800), with the United States at 3% (52,700), Brazil at 4% (20,500 cases), India at 5% (62,100), China 6% (282,300), Germany 4% (21,500 cases) and France at 5% (20,000 cases - see Appendix table 4 for country level data).
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.
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, the authors say. Tax and pricing policies have led to decreased alcohol intake in Europe.
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. In addition, there is evidence that the COVID-19 pandemic has increased rates of drinking in some countries.
There are several limitations to the study, including the potential effect of the COVID-19 pandemic, which has impacted behaviors including alcohol drinking and also cancer services in many countries and could have affected cancer risks and diagnosis rates. Further, the main study analysis did not take into account former drinking, or any relationships between tobacco or obesity with alcohol, which could have attributed some cases to alcohol that were actually driven by, for example, smoking.
Professor Amy C. Justice, Yale University, (who was not involved in the study), notes that estimating the effects of alcohol intake on cancer rates across countries is notoriously difficult. She writes that a quarter of alcohol purchases are not captured by government data, making it difficult to estimate accurate sales figures. "Until we address limitations in measurement, we might be underestimating health risks, especially cancer risks, associated with alcohol," she said.
Read the full study.