Are You At Risk Of Breast Cancer?
The risk of developing breast cancer is a combination of many factors both environmental and genetic. Women are more likely to develop breast cancer than men.
Having a risk factor doesn’t automatically mean that you will get the disease, as some women with similar risk factors may not eventually have the disease. Even some women with no risk factor may still get breast cancer.
If you think you might be at risk of breast cancer it is important to visit your doctor about ways to reduce your risk and you’ be properly screened for the disease.
What Are The Risks associated With Breast Cancer?
Certain factors increase an individual’s chances of developing breast cancer. Risk factors on their own do not cause breast cancer however, studies have shown that many people who have or have survived breast cancer have been found to have some of these risk factors.
Risk factors can be categorized as those that can be modified and those that can not be modified.
Risk factors that can be changed
Research studies show that drinking alcohol is highly and consistently associated with the risk of breast cancer.1,2,3,4,5,6,7
According to The International Agency for Research, low to moderate intake of alcoholic beverages, greatly increases an individual’s risk of breast cancer and this risk increases with higher alcohol intake.1
There is a strong correlation between alcohol, whether light or heavy consumption on the risk of breast cancer through; alcohol metabolism to carcinogens (cancer causing) byproducts, and in the way it increases hormone levels and E2+ estrogen receptor positive cells, reactive oxygen species, inflammation and altering other biologic pathways in the body.2,3,6
Being overweight or obese after menopause is associated with a high risk of breast cancer.8,9 This is because prior to menopause the ovaries make most of the estrogen in the body while the fat tissues make very minimal amount. After menopause, the ovaries no longer make estrogen, so all estrogen come from fat tissue and having more fat tissue means more estrogen. High estrogen levels in the body predisposes the postmenopausal woman to breast cancer. 10
Obese women tend to have higher blood insulin levels and high insulin in the body has been linked to cancers breast cancer inclusive. 11
Not exercising regularly increases the risk of breast cancer. 12 As little as a couple of hours per week is highly helpful and the American Cancer Society recommends about 75 minutes of vigorous exercise or 150 minutes of moderate intensity activity per week.
Use of Birth Control
Oral contraceptive use is related to the increased risk of breast cancer. Research has shown that women who have used oral contraceptive pills have higher chances of developing breast cancer when compared to women who have never used it. It takes about 10 years of stopping the pills to be clear of the associated risk.
Contraceptive implants, intrauterine devices (IUDs), skin patches and vaginal rings are hormone based and can increase an individual’s risk of breast cancer, especially hormone based IUDs.
Hormone Replacement Therapy (HRT)
This used to be recommended for postmenopausal women to help with symptoms of menopause such as hot flashes and fatigue.
Individuals on hormone replacement therapy both estrogen only or progesterone and estrogen combination therapy are at risk of breast cancer.
Combination HRT has the higher risk of the two, at 75% even for short period of use. It is also likely that the cancer associated with C-HRT will be detected late and the chances of survival will be reduced. It takes about 3 years to clear the associated risk. If one must use C-HRT, a low dose is recommended as it has lower risk.
Estrogen-only HRT is associated with less risk when compared C-HRT and the risk is at the highest when used for greater than 10 years.
A woman is at risk of breast cancer if she has not had a child or carried a child to term before age 30.
Prior to the first full term pregnancy, the breast remain in the immature, underdeveloped state until when the person becomes pregnant. The immature breast cells respond highly to estrogen and carcinogens that may induce them to transform to cancer cells.
Earlier pregnancy (>30years) reduces the risk of breast cancer.
Breastfeeding can lower the risk of breast cancer especially in mothers that breastfed their children for more than 1 year.
Smoking is related many cancers including breast cancer. Also, second hand smoking also increases one’s risk.
Risk Factors That Cannot Be Changed
The older a woman gets the more likely she is to get breast cancer. The incidence of breast cancer is higher in women over the age of 40. However, it can happen to women less than 40, in fact, of all the women in the US diagnosed of breast cancer about 4% are less than 40 years old. The average are for breast cancer is about 62 years.14
Women are at a higher risk of breast cancer, however, about 1% of all cases of breast cancer occurs in men.
Race and Ethnicity
The role of race and ethnicity in the incidence and death by breast cancer depend on the age of onset.
White women are more likely to develop breast cancer after the age of 40 years. 14
The risk of developing breast cancer in women below the age of 40 is higher in Black women and they are more likely to die from breast cancer regardless of age at diagnosis.
Family History Of Breast Cancer
Having an immediate family member (parents, siblings or child) with history of breast cancer increases an individual’s risk.
Family history of other cancers like ovarian, prostatic or pancreatic cancers will increase one’s risk of breast cancer. 16
3-7% of women who have had breast cancer in the past are at an increased risk of developing new cancer. 17
Inheriting the breast cancer genes, BRCA1 and BRCA2, puts an individual at risk of breast cancer. According to studies, genetic variations in BRCA genes account for about 10% of all breast cancer diagnoses.16
Personal History of Previous Breast Conditions
History of previous benign breast conditions including fibrocystic disease, fibroadenoma or any growth in the breast with atypical growth on biopsy.18,19,20
Other risk factors associated with breast cancer
Menstruation history: Risk of developing breast cancer is higher in women who started menstruation relatively early or those with later menopause. The risk is higher in women who began menstruating before the age of 11 or those who experience menopause at age 55 or later. This is because of longer lifetime exposure to female reproductive hormones.21
High levels of female hormones: Postmenopausal women with high circulating hormone levels are at risk of breast cancer.22
Breastfeeding: Breastfeeding for at least one year reduces the risk for developing breast cancer. Also, women who have never breastfed are at a relatively high risk of developing breast cancer.23
Expoosure to diethylstilbesterol in the uterus: DES was given to some pregnant women in the past because it was thought to reduce the chances of them having a miscarriage. These women are at an increased risk of breast cancer. In addition, women whose mothers took diethylstilbestrol (DES) are also at risk of getting breast cancer.24
Exposure to radiation: Previous treatment with high dose radiotherapy to the chest between the ages of 10-30 years of age has been linked to breast cancer. It is thought that breast tissue is susceptible to carcinogens during this period. The risk of breast cancer due to radiation exposure starts at about 8 years following exposure ab peaks at about 35 years after. 25
Exposure to environmental chemicals: Exposure to chemicals and pollutants in the environment may increase an individual’s risk of breast cancer. According to a recent study, fetal exposure to DDT (dichlorodiphenyl trichloroethane), is linked to increased risk of breast cancer later on in life.30,31
Working night shift jobs: Several studies have shown that people who work night shift such as nurses, security personnel and flight attendants are at risk of breast cancer due to disruption of the circadian rythm, which directly affects melatonin production. Melatonin is a hormone in the body responsible for sleep regulation and it is affected by exposure to light. Melatonin is also thought to suppress the growth of small tumors and preventing new ones. When the production of melatonin is disrupted, chances of breast cancer increases.26,27,28,29