Introduction
Globally, breast cancer is among the most prevalent cancers affecting women (and India is no exception).
In the past several years, especially among younger women, cases of breast cancer have sharply increased. Although hearing the word “cancer” can be terrifying, learning about its causes can mitigate the fear and promote awareness, early diagnosis, and treatment.
Let’s take a look at what actually causes breast cancer (in plain language).
How Breast Cancer Develops (Scientific Explanation in Simple Terms)
We are made up of cells, which grow, divide, and die all in an orderly process. Breast cancer occurs when some cells in the breast start to grow out of control and get bigger and form a lump or tumor. When those cells grow and grow, over and over, they may spread to the nearby tissue and even other parts of the body.
Breast cancer usually starts in the milk ducts or lobules (the part where milk is made) as a result of mutations (changes) that occur in DNA that makes the cells grow. Some mutations are inherited, and others arise with time.
Genetic Causes of Breast Cancer
A small number of breast cancers, about 5% to 10%, are hereditary, which means they are passed within families. The most well-studied genes associated with inherited breast cancer are
BRCA1 and BRCA2: If you have a mutation in either of these genes, you have a greatly increased risk for cancer of the breast and ovary.
Family history: If your mother, sister, or grandmother was diagnosed with breast cancer, you may have an even greater risk.
However, remember that most women with breast cancer have not had any other family member with this diagnosis. Genetics is only one part of the picture.
Hormonal and Biological Causes
In breast tissue development, the hormones estrogen and progesterone are central elements. However, lifetime exposures to high levels of those hormones increase the risk of breast cancer.
This is where some factors come into play:
- Early menstruation (before age 12)
- Late menopause (after age 55)
- Never having children or having them late
These factors may signal higher levels of hormone exposure and risk.
Lifestyle and Environmental Risk Factors
There are a few lifestyle behaviors and exposures to environmental factors that can increase the chance of developing breast cancer:
- Not exercising enough
- Obesity, particularly post-menopause
- Heavy alcohol use
- Use of tobacco products
- An unhealthy diet (low in fruits, vegetables, and fiber)
- Exposure to radiation or hazardous chemicals
These risk factors do not determine who will develop cancer, but they definitely increase risk over time.
Age and Gender as Key Risk Factors
Women have a likelihood of developing breast cancer that is 100 times that of men.
Women are older compared to men when diagnosed with breast cancer, with risk increasing with age, specifically after the age of 50.
Due to years of hormonal exposure, postmenopausal women are more likely to be diagnosed.
Breast Density and Tissue Type
Women with dense breast tissue could have a slightly increased risk of breast cancer. Dense breast tissue has a greater proportion of glandular and connective tissue compared to fatty tissue, meaning that tumors are also harder to detect on mammograms.
That is why your doctor may recommend an ultrasound or an MRI if you have dense breast tissue.
Reproductive and Menstrual History
Your reproductive history can influence breast cancer risk in the following ways:
- Having first child after 30
- Never being pregnant
- Not breastfeeding
- Longer menstrual years (early periods + late menopause)
All of these factors increase estrogen exposure, which can increase risk.
Can Birth Control Pills or HRT Cause Breast Cancer?
This is a frequent concern, and the answer is not as simple as yes or no.
Birth control pills can increase risk, although the risk goes back to normal after stopping the pill for about 5-10 years.
Hormone Replacement Therapy (HRT) after menopause may increase the risk of breast cancer, especially after you have been taking HRT for several years.
You should discuss any hormonal treatment with your doctor before you start or stop taking any hormonal treatment.
Myths vs. Facts: What Doesn’t Cause Breast Cancer
Let’s clear up some misconceptions:
- Are underwire bras ok to wear? They don’t cause cancer.
- Are deodorants or antiperspirants ok to use? There is no strong evidence.
- Does a breast injury cause cancer? No.
- Does touching or squeezing breasts too much cause cancer? No.
Instead of worrying about these myths, we should be focusing on proven actual factors and screening regularly.
How to Reduce the Risk of Breast Cancer
Genetics is beyond your control, but there is so much you can do:
- Keep a healthy weight
- Exercise (30 min a day is fine)
- Limit alcohol and stop smoking
- Eat a balanced diet with lots of fiber, fruit, and vegetables.
- Breastfeed if you are able
- Go for regular checkups/screenings (especially after 40 or earlier if you are at risk).
If caught early enough, anything can be treated. Don’t neglect your medical checkups.
Conclusion
Breast cancer does not have a simple cause. It is often a combination of genetic factors, hormones, age, and lifestyle. But knowledge is power! Now that you understand why breast cancer might happen, you can make a more informed decision in making your lifestyle or health changes or accessing detection and support measures and potentially even inform another person of similar need.
Because with breast cancer, awareness leads to action, and action can make a difference.
FAQ
- Can stress lead to breast cancer?
There’s no direct evidence that stress causes breast cancer; however, chronic stress can impact your immune system and health in general, which can make prevention and recovery more difficult.
- Is breast cancer always hereditary?
No. Only 5-10% of breast cancer cases are hereditary. Most breast cancer cases occur in people without any family history of the disease.
- Can men develop breast cancer?
Yes, even though it’s not common. Men have breast tissue too, and approximately 1% of breast cancer cases occur in men.
