Risk Factors Of Breast Cancer
Recognising the Risk Factors of Breast Cancer Can Help in Prevention and Early Detection
A risk factor of cancer is an aspect that increases the probability or likelihood of developing cancer that we have stated below. However, it does not guarantee that the cancer will occur.
An example of a risk factor is having a family history of breast cancer. Family history increases the chances of having a specific gene mutation like Breast Cancer Gene 1 (BRCA1) and Breast Cancer Gene 2 (BRCA 2). Because mutation of these genes causes DNA damage and genetic changes that allow cells to grow uncontrollably and become cancerous. Therefore if someone has these mutation, they are more likely to develop the disease but further investigation is needed, as the mutation only increases the risk but does not guarantee breast cancer.
Risk factors of breast cancer are of various types; they can be genetic (unavoidable risk), environmental, or lifestyle-related (avoidable risk). Interestingly even though these factors are not always the sole reason for breast cancer, it is seen that individuals who don’t have the risk factors can also develop cancer, it’s important to know them because everyone is at risk of breast cancer, and some of us are at a higher risk than others.
Understanding these factors will help people take charge of their health, make smart choices about prevention and early detection, and feel less worried about getting breast cancer. Furthermore take a self check and see if any of risk factor listed below applies to you.
It is important to note that if an individual encounters any of the risk factors mentioned below, it is advised to consult a doctor before taking further steps.
Let’s understand various types of risk factors associated with Breast Cancer
Risk factors of breast cancer are majorly divided into unavoidable risk factors and avoidable risk factors
Unavoidable Risk Factors
Factors you can’t control or modify are termed as unavoidable risk factors. These are the factors with which you’re born or develop over time, and they make you more likely to get breast cancer. Understanding these factors helps doctors as well as individuals make decisions about genetic testing in terms of if the risk factor is genetic and pursuing early screening for breast cancer.
Below are the most common unavoidable risk factors in breast cancer :
Getting older raises the risk of breast cancer. This is because as we age, our breast cells divide more, which can lead to mistakes (mutations) that cause cancer.
Also, the hormone estrogen, which can make breast cells grow and raise cancer risk, increases as we age.
That’s why as in most cases of breast cancer it is seen that women between 40 to 50 have a medium chance of getting breast cancer, while those between 50 to 60 have the highest risk.
Gender is among the common risk factors as breast cancer is much more common in women than in men because women have more breast tissue and higher levels of hormones like estrogen and progesterone, which can promote cancer growth.
Also women have dense breast tissue than men, providing more cells that could potentially become cancerous. Additionally, genetic factors such as BRCA mutations increase the risk of breast cancer, and these mutations affect women more often.
Although men can get breast cancer, it is about 100 times more likely in women due to these differences.
Reproductive history is a key risk factor for breast cancer, involving two main aspects: early menarche and late menopause.
All three are linked to higher levels of estrogen, a major factor in breast cancer.
Early menarche (starting periods before age 12) means longer exposure to estrogen, raising cancer risk.
Late menopause (after age 55) also results in longer estrogen exposure, increasing the risk.
The higher risk of breast cancer in women with close blood relatives who have the disease is mainly due to inherited genetic mutations. These mutations can be passed down through generations, increasing the risk for women with a family history of breast cancer.
Even though inherited genes are the most common reason for this increased risk, it is still hard to tell if the pattern of cancer in a family is due to chance, shared lifestyle factors, inherited genes, or a mix of these. The family structure and the age at which relatives were diagnosed also affect the risk.
For example : Having a first-degree relative (mother, sister, or daughter) with breast cancer nearly doubles a woman’s risk of getting breast cancer.
Women with a father or brother who has had breast cancer also face a higher risk.
Risk is lower for second- or third-degree relatives such as aunts, grandmothers, and cousins.
Women with certain benign (non-cancerous) breast conditions may have a higher risk of breast cancer.
These conditions are grouped based on their risk levels.
Non-proliferative lesions, like fibrosis, simple cysts, and mild hyperplasia, have little to no impact on breast cancer risk.
Proliferative lesions without atypia, such as usual ductal hyperplasia and fibroadenoma, slightly raise the risk.
Proliferative lesions with atypia, including atypical ductal hyperplasia (ADH) and atypical lobular hyperplasia (ALH), increase the risk about 4 to 5 times.
Lobular carcinoma in situ (LCIS) is not cancer but boosts breast cancer risk by 7 to 12 times
As breast density is an inherited trait, it comes under unavoidable risk factors for breast cancer.
A breast is a mix of fatty, fibrous, and glandular tissue.
Dense breasts have more glandular and fibrous tissue and less fat. Because of this, if a woman has dense breasts during a mammogram test, it becomes difficult to distinguish a tumor as dense tissue looks white, like tumors. Therefore, the chances of missing out on cancer increases.
Inherited gene changes are an unavoidable risk factor for about 5% to 10% of breast cancer cases.
The most common genetic mutations are in the BRCA1 and BRCA2 genes, which greatly increase the risk of breast cancer.
These mutations can also lead to ovarian and other cancers. Less common gene mutations like ATM, PALB2, TP53, CHEK2, PTEN, CDH1, and STK11 also raise breast cancer risk.
These inherited genes can be determined through a genetic test, which an individual may consider undergoing after consulting with the doctor.
Exposure to ionizing radiation can increase the risk of breast cancer because it can damage the DNA in breast cells.
This damage can cause mutations, which are changes in the DNA that can make cells grow uncontrollably and form cancer.
Ionizing radiation, like X-rays and gamma rays, has a lot of energy that can change the structure of cells, leading to these harmful mutations.
The risk of developing a new type of breast cancer in the other breast or in another part of the same breast where cancer had previously been is higher due to several reasons, such as genetic factors, lifestyle and environmental factors that contributed to the first cancer.
However, it is unclear whether one single reason is responsible or if it is a combination of all factors.
Additionally, it is important to understand that this type of cancer is different from the recurrence of the previous cancer, as it is a completely new formation of cancer.
Therefore, it is crucial to monitor health if one has previously faced breast cancer, and routine checkups play a very important role.
Higher levels of sex hormones like estrogen, progesterone, and testosterone can increase the risk of breast cancer.
Testosterone, typically a male hormone, also affects this risk in women, as they have small amounts of it in their bodies.
After menopause, women with higher levels of estrogen and testosterone in their blood may have a higher risk of breast cancer.
Similarly, women with higher testosterone levels before menopause are also at greater risk.
Additionally, elevated levels of a hormone called insulin-like growth factor 1 (IGF-1) are linked to increased breast cancer risk. However, it is extremely unclear whether the factors controlling IGF-1 levels are genes, body weight, and exercise levels.
Avoidable Risk Factors
Avoidable risk factors for breast cancer are factors that can be changed through lifestyle choices or environmental adjustments. By making changes in these risk factors, an individual can improve their overall health as well as take precautionary measures for breast cancer.
Below are the most common avoidable risk factors in breast cancer :
As higher estrogen levels are linked to an increased risk of breast cancer in women, alcohol consumption plays a significant role in causing a rise in the level of estrogen in the blood as it can change the way a woman’s body metabolizes estrogen.
Therefore, alcohol consumption is a risk factor for breast cancer, as it has been found that estrogen levels are higher in women who drink alcohol than in non-drinkers.
Being overweight or obese increases the risk of breast cancer because fat tissue produces estrogen. For example, in women after menopause, when the ovaries stop making estrogen, fat tissue becomes the main source of this hormone.
Higher levels of estrogen can help breast cancer grow.
Additionally, obesity can lead to higher insulin levels and long-term inflammation, which can also help cancer develop.
To measure whether a person is overweight, Body Mass Index (BMI) is used. BMI uses height and weight to determine if you are at a healthy weight.
The use of oral contraceptives, specifically the combined use of estrogen and progesterone, increases the risk factor for breast cancer. This is because the hormones in the pill can stimulate breast cell growth and increase the risk of breast cancer.
However, the risk of breast cancer decreases after the pill is stopped, as the hormones are no longer present in the body to stimulate breast cell growth.
It is important to note that breast cancer is rare in young women. Most women who take the pill are in their late teens, twenties and early thirties. So a small increase in this risk during the time women take the pill means very few extra cases of breast cancer.Therefore it is important to consult with the doctor about the benefits and risks of taking the contraceptive pill.
Regarding reproductive history-related risk factors, not breastfeeding and having a child after age 30 are the two aspects that can increase the risk of breast cancer.
Not breastfeeding raises estrogen levels, which can make breast cells grow more and increase cancer risk. Breastfeeding helps produce hormones that control breast cell growth, so not breastfeeding can raise the risk of cancers related to hormones.
Having a child after age 30 increases the risk because the body has been exposed to estrogen and progesterone for a longer time, making breast cells grow more and raising the risk of cancer.
Hormone replacement therapy (HRT), also known as menopausal hormone therapy (MHT), is a treatment used to relieve symptoms of menopause and prevent bone thinning (osteoporosis).
However, it can also increase the risk of breast cancer due to several factors:
First, HRT raises estrogen levels, which can stimulate breast cell growth.
Second, the longer a woman uses HRT, the higher her risk becomes. The risk is especially higher with combined HRT, which uses both estrogen and progesterone. This type of HRT not only increases the risk of developing breast cancer but also the risk of the cancer being detected at a more advanced stage.
Lastly, HRT can change the density and types of breast tissue, making it easier for cancer to develop.