Picture yourself at a party where everyone is merrily chatting, laughing, and having a good time. It's simple to lose yourself in the moment and go for another alcoholic beverage. However, it might be wise to think about what's in that glass and how it affects your health before you do. Although drinking alcohol in moderation might seem like a harmless way to relax, alcohol has a darker side.

Alcohol has numerous detrimental effects on health. Chronic alcohol consumption can lead to a number of long-term disorders in addition to the typical hangover symptoms. These include cancer, digestive issues, neuropathy, liver damage, and cardiovascular illnesses including hypertension. Drinking alcohol increases the risk of developing numerous cancer kinds. Breast cancer is one of them.

One of the most common cancers that affects a lot of women worldwide is breast cancer. This article explores the possible causal association between alcohol use and breast cancer.

Introduction

Overview of breast cancer

Breast cancer is marked by the unchecked proliferation of cells that form a tumour in the breast region. It is the second most common cause of cancer-related deaths worldwide and one of the most common malignancies identified in women.

Skin changes, breast form changes, discharge, and lumps are among the symptoms. The prognosis of the disease and the patient's lifetime are greatly improved by early diagnosis by employing screening prior to the onset of symptoms.¹

Brief overview of alcohol consumption

Alcohol is a type of beverage that includes ethanol and other psychotropic ingredients. It is commonly used in many cultures and has the potential to cause dependence. Most individuals drink to unwind after a long day, celebrate an accomplishment, or interact with friends and coworkers. On the other hand, drinking alcohol regularly can have a number of negative health impacts.²

The higher your blood alcohol concentration (BAC), the more impaired your bodily functions tend to become. Some common effects include: 

• Reduced inhibitions
• Confusion
• Slurred speech
• Motor impairment
• Memory and concentration problems³

Understanding breast cancer

Types of breast cancer

Ductal carcinoma in situ (DCIS)

One kind of breast cancer that is non-invasive is called ductal carcinoma in situ (DCIS). It is caused by the unchecked growth of epithelial cells that line the breast milk ducts but have not yet spread outside of them. Usually treated with surgery, hormone therapy, or radiation therapy, it is the most curable type of breast cancer.⁴

Invasive ductal carcinoma (IDC)

With 80% of cases, invasive ductal carcinoma (IDC) is the most prevalent form of breast cancer in women. It is an aggressive and malignant kind of breast cancer, as the name implies. It begins with the milk ducts' uncontrollably growing cells and progressively extends to other breast tissues.⁵

Invasive lobular carcinoma (ILC)

Approximately 15% of all occurrences of breast cancer are invasive lobular cancer (ILC), sometimes referred to as lobular breast cancer. It is the second most frequent kind of breast carcinoma. It begins in the milk-producing glands, or lobules, of the breast and gradually spreads to the other breast tissues.⁶ 

Triple negative breast cancer (TNBC)

A unique kind of invasive breast cancer is called triple negative breast cancer. Human epidermal growth factor receptor 2, progesterone receptors (PR), and oestrogen receptors (ER) are absent from the cells in this kind of cancer. More than 15–20% of all breast cancers are caused by them. Because of its extremely invasive nature and poor response to treatment, TNBC has been extensively studied.⁷

Inflammatory breast cancer 

An uncommon and invasive form of breast cancer is called inflammatory breast cancer. In this type of cancer, the skin's lymphatic vessels are blocked by the cancer cells. It makes the breast appear red and itch. It only makes up 1 to 5% of instances of breast cancer overall, and its death rate is 7%.⁸

Paget disease of the breast

Mammary Paget disease, sometimes referred to as Paget disease of the breast, is an incredibly rare sign of underlying breast cancer. It typically appears in DCIS or IDC instances. It makes up 1-3% of all cases and is more common in postmenopausal women. It starts in the breast duct and moves slowly to the areolar region and the nipple.⁹

Angiosarcoma

Less than 1% of instances are angiosarcoma, a soft-tissue sarcoma that is malignant by nature. They are produced by vascular or lymphatic endothelial cells. It may result in the formation of purple coloured lumps or nodules in the breast tissue. The prognosis is bad and therapy for this kind of breast cancer might be difficult.¹⁰

Phyllodes tumour 

The phyllodes tumour is another uncommon kind of breast cancer. They account for 0.3 to 0.5 percent of all breast tumours in women. Rather than the ducts or glands, it starts in the stroma, the connective tissue surrounding the breast. Because of their propensity for cancer, they must receive the right care.¹¹ 

Risk factors for breast cancer

Genetic factors

Research has demonstrated that a person's genetic makeup significantly influences their chance of developing breast cancer. Among the well-known genes linked to cancer risk are those mutated in specific genes, such as BRCA1 and BRCA2. They make up five to ten percent of cases of breast cancer overall. Genes such as TP53, PTEN, and CHEK2 are among the others that may be mutated genetically to raise the risk of breast cancer. A family history of breast cancer increases the risk much more.¹²

Hormonal factors

An increased risk of breast cancer is linked to prolonged exposure to female hormones such as progesterone and oestrogen. Consequently, women who started menstruation early (before the age of 12) and went through menopause at a later age (beyond the age of 55) are at higher risk. Another potential risk factor is hormone replacement medication, such as HRT, particularly in postmenopausal women. Nulliparity and having the first child at a late age may also raise hormone exposure, according to research. Lastly, there is a correlation between the risk of breast cancer and obesity.¹²

Lifestyle & environmental factors

There are a number of non-hormonal factors that account for breast cancer. Increased alcohol intake, usually correlates to a higher risk of breast cancer. Other lifestyle factors contributing to the risk include smoking, obesity, dietary habits, and lack of physical activity. Environmental factors involving exposure to ionising radiation also pose a risk of developing breast cancer.¹²

Alcohol consumption

Patterns of alcohol consumption

Moderate drinking

Moderate drinking is typically defined as no more than one drink per day for women and two drinks per day for men. A drink usually refers to 14 grams of pure alcohol that is equivalent to a 12-ounce beer, a 5-ounce glass of wine, or a 1.5-ounce shot of spirits. Although it has certain benefits like reduced heart disease risk, it still is a potential risk factor for cancers like breast cancer.¹³ 

Heavy drinking

Heavy drinking typically refers to more than three drinks per day or seven in a week for women, and more than four drinks per day or fourteen per week for men. This pattern of consumption significantly raises the risk of numerous health issues, including liver disease, cardiovascular problems, and various cancers, notably breast cancer.¹⁴

Binge drinking

The National Institute on Alcohol Abuse and Alcoholism (NIAAA) defines binge drinking as a pattern of drinking that causes a person’s blood alcohol concentration (BAC) to be 0.08% or higher within a 2 hour time period. It amounts to typically four drinks in women and five drinks in males over two hours. Long-term binge drinking can increase the likelihood of developing chronic health issues such as breast cancer.¹⁵

The link between alcohol and breast cancer

Studies showing the potential link

There is a plethora of research that proves that alcohol consumption increases the risk of breast cancer in people. The earliest studies can be dated back to 1987 when the New England Journal of Medicine published reports that proved this hypothesis. The association between alcohol and breast cancer was found across a range of geographical locations and drinking patterns.

The study also mentions that even moderate levels of intake can be a risk for breast cancer.¹⁶ In a 2018 update, collaborative research between the World Cancer Research Fund and the American Institute for Cancer Research (WCRF-AICR) stated a causative link between the same, accounting for increased risk in 5% among premenopausal women and 9% among postmenopausal women.¹⁷ 

Biological mechanisms

There are several biological mechanisms that explain the correlation between alcohol consumption and breast cancer risk. Some of them include:

• Alcohol can cause hormonal imbalance. It increases the amount of oestrogen in the blood which, in turn, leads to prolonged exposure and an increased risk of developing breast cancer
• Alcohol metabolism can cause oxidative stress among cells by increasing reactive oxygen species (ROS) which leads to carcinogenesis
• The metabolite of alcohol is acetaldehyde which is carcinogenic. It can lead to mutations and DNA damage
• Alcohol interferes with folate (Vitamin B9) metabolism. Folate deficiency causes instability in DNA and can lead to mutations
• Lastly, alcohol consumption can lead to epigenetic alterations, such as DNA methylation changes, that affect gene expression involved in cell growth and differentiation, potentially promoting cancer development¹⁸ 

FAQs

What cancers are caused by alcohol?

Answer: Alcohol poses an increased risk of cancers: for example the mouth, pharynx (throat), larynx (throat), oesophagus, liver, breast, and bowel.

How much alcohol is safe to drink daily?

Answer: Women should drink no more than 1 drink per day and men should drink no more than 2 drinks per day.

Summary

• Breast cancer is a disease that affects a large percentage of women all around the world and includes different types and subtypes
• Various risk factors pose a threat to breast cancer occurrence in a person like genetic, hormonal, lifestyle, and environmental factors
• Research over the years has shown a causative relationship between different drinking patterns and breast cancer. Many biological mechanisms have been explained indicating the same