Does Alcohol Consumption Put Women At Higher Risk Of Breast Cancer?

In France, one in eight women will be confronted with breast cancer during her lifetime. Among the risk factors is alcohol consumption: each year, 8,000 cases of breast cancer out of the 61,000 detected are attributable to it, according to the National Cancer Institute. What mechanisms are at play, and what are the implications in terms of care and treatment?

Every year in France, since 1994, the month of October has been dedicated to raising awareness of breast cancer, as part of the Pink October campaign. The opportunity, in particular, to focus on screening. Let us remember that, if detected early, breast cancer is curable 9 times out of 10. But Pink October is also an opportunity to recall the importance of prevention and healthy lifestyle habits.

Among the many risk factors for breast cancer, there is one that is particularly worrying: alcohol consumption. What are the biological mechanisms underlying the links between alcohol and breast cancer? What are the recommendations for prevention? Alcohol withdrawal? Here are some answers.

Leading cause of death among women in France

In France, breast cancer affects approximately one in eight women during their lifetime, making it the most common cancer in women. It is also the one that causes the highest number of cancer deaths in the female population: 14% of cancer deaths in 2018 were due to breast cancer.

This cancer represents about 30% of cancers diagnosed in women in our country. In 2023, nearly 61,000 new cases were recorded, resulting in 12,000 deaths .

Furthermore, a study by the National Cancer Institute (INCa) indicates that for the year 2015, among people aged 30 and over, nearly 28,000 new cases of cancer (11,700 among women and 16,200 among men) were attributable to alcohol consumption, or 8% of new cases of cancer of all locations combined (7.5% and 8.5% of new cases of cancer among women and men respectively).

These statistics highlight the need for increased awareness and preventative measures.

Alcohol and cancer risk: a well-established link

Although still often underestimated or misunderstood, the carcinogenic nature of alcohol is now clearly demonstrated. Alcohol is the second leading preventable cause of cancer death, after tobacco. Since 1988, this substance has been classified as carcinogenic to humans by the International Agency for Research on Cancer (IARC).

This harmful effect of alcoholic beverages is due to ethanol, their main constituent. Once ingested, this molecule is in fact metabolized into compounds that can promote the development of cancers. This is the case, for example, of acetaldehyde, which can cause DNA damage that, if not repaired, can lead to cancers.

Cancer risk depends on the total amount of alcohol consumed, rather than the type of drink (wine, beer, aperitifs). Studies have shown that increased alcohol consumption increases the risk of breast cancer by 5% in premenopausal women and 9% in postmenopausal women for each unit of alcohol (about 10 g of ethanol) consumed per day.

However, this risk is often underestimated in France: only 58.4% of French people recognize that moderate alcohol consumption increases the risk of cancer .

Conversely, reducing alcohol consumption, or even abstinence, can significantly reduce the risk .

Alcohol and breast cancer

According to INCa, in France, each year, 8,000 cases of breast cancer are attributable to alcohol consumption .

Research has highlighted several mechanisms by which alcohol promotes the development of breast cancer . Alcohol has the ability to raise blood levels of estrogen. These hormones play a central role in the development of certain types of breast cancer, particularly those described as "hormone-dependent."

The risk of breast cancer begins to increase as soon as a person consumes alcohol, even at amounts less than one drink per day. In the UK, analysis of data collected during the Million Women Study , which included more than 28,000 women with breast cancer, suggests that for every 10 grams of alcohol (one drink) consumed per day, there is a 12% increase in the risk of breast cancer .

Conversely, there is a gradual decrease in the risk of breast cancer in women who have stopped drinking, with a reduction of 20-30% after five years of abstinence .

And that's not all: withdrawal also improves the response to anticancer treatments, reduces their side effects, and lowers the risk of recurrence. And not just in the case of breast cancer.

Impact of alcohol withdrawal on cancer survival

In clinical practice, only 0.9% of cancer patients were informed about the possibility of obtaining help to reduce excessive alcohol consumption. This low level of consideration of alcohol consumption raises questions about the place of prevention in cancer therapy.

Now, this is not a trivial question. Indeed, cancer patients who stop drinking alcohol see their response to treatment improve, with an increase in survival rates of 15-25% in some types of cancer, such as esophageal and head and neck cancers .

Alcohol withdrawal is also associated with a reduction in the side effects of treatments, as well as a reduced risk of cancer recurrence , with a significant improvement in patients' quality of life.

Weaning: what strategies?

Alcohol withdrawal is a complex process that requires appropriate professional care. Support from addiction specialists is essential to overcome the challenges of withdrawal. Alcohol withdrawal can cause different symptoms such as tremors, sleep disturbances, nausea, anxiety. These symptoms can be exacerbated in breast cancer patients , due to the stress related to the disease. These withdrawal challenges vary from one person to another.

Regular consultations allow progress to be monitored, treatments to be adjusted and relapses to be prevented. Finally, psychosocial support, including therapies and discussion groups, reinforces motivation and improves the patient's environment, thus increasing the chances of success. Various associations are involved in this goal, such as the Ligue contre le cancer and the Europa Donna France association .

It cannot be said enough: alcohol is a major risk factor for breast cancer, and one that is too little known. Promoting alcohol withdrawal could play a crucial role not only in reducing the incidence of this cancer, but also in improving survival.

Recommendations for limiting alcohol consumption and cessation strategies should be widely disseminated and integrated into cancer prevention and treatment programs.

To conclude, let's reiterate the recommended alcohol consumption guidelines in France: do not consume more than ten standard glasses per week; do not consume more than two glasses per day; have days without consumption in a week: "for your health, alcohol is a maximum of two glasses per day and not every day" .

This article was first published in The Conversation. Writers: Ingrid Marcq, Researcher, Research Group on Alcohol and Drug Dependencies (GRAP) INSERM 1247, University Health Research Center (CURS) and head of team 70 of the Nutrition, Food and Cancer Network (NACRe), University of Picardie Jules Verne (UPJV). Anoïsia Courtois, PhD student in biology-health, Research Group on Alcohol and Drug Dependencies (GRAP) Inserm 1247, University of Picardie Jules Verne (UPJV).