Breast cancer is a common cancer, but experts are still not sure why this might be. However, researchers have identified certain risk factors for breast cancer, such as physical inactivity and having obesity.
A note about sex and gender
Sex and gender exist on spectrums. This article will use the terms “male,” “female,” or both to refer to sex assigned at birth. Click here to learn more.
The majority of breast cancers start in the cells of glandular tissue in the breast. It is the
This article examines why breast cancer is so common. It also looks at the prevalence of breast cancer and risk factors a person can control.
Experts are still unsure why breast cancer is so common, but they do know of certain factors that increase the risk of breast cancer. Being female is the
When breasts are fully formed, the breast cells are immature and very active until a person goes through a full-term pregnancy. Immature breast cells are responsive to hormones such as estrogen. The increased responsiveness of female breast cells to hormones increases the risk of developing breast cancer.
Males do not typically develop fully-formed breasts, and they usually consist of fat. The breast cells are inactive, and most males have low levels of estrogen.
Age is the
Gene mutations can also lead to breast cancer. The
According to a 2022 article, risk factors for breast cancer worldwide include:
- experiencing menopause at a later age
- undergoing hormone replacement therapy
- using hormonal contraception containing estrogen long term
- getting married at a later age
- having the first childbirth at a later age
- having a late-night work schedule
- eating a nonvegetarian diet high in animal fat
- not getting enough physical activity
- having obesity
- lacking the proper awareness or screening
- receiving a delayed diagnosis
- not having access to sufficient healthcare facilities
Alcohol intake is also a risk factor for breast cancer. Moderate alcohol consumption of more than 35–44 grams per day, or about three or four standard drinks, increases the risk of breast cancer by 46%. According to the
The ACS estimates that in 2022, there will be around 287,850 new cases of invasive breast cancer diagnoses in the U.S.
Breast cancer mostly affects females with a median age of 60–62 years at the time of diagnosis. Fewer females are diagnosed with breast cancer under the age of 45 years.
Among females under the age of 40 years, Black females have a higher risk of developing breast cancer than white females.
According to the World Health Organization (WHO),
- not being physically active
- having obesity or being overweight after menopause
- taking hormone replacement therapy for more than 5 years
- taking certain hormonal contraceptive pills
- having a first pregnancy after the age of 30 years
- not breastfeeding
- never having a full-term pregnancy
- drinking alcohol
- working night shifts, which may cause hormone changes
- being of older age
- having a genetic mutation
- starting menstrual periods before the age of 12 years
- starting menopause after the age of 55 years
- having dense breasts
- having had breast cancer previously
- having certain noncancerous breast diseases
- having a family history of breast cancer or ovarian cancer
- having previous radiation therapy to the chest before the age of 30 years
- receiving exposure to the drug diethylstilbestrol (DES)
Although there is no definite way to prevent breast cancer, people may be able to
- reaching and maintaining a moderate weight
- staying physically active
- aiming for at least 150–300 minutes of moderate-intensity exercise, or 75–150 minutes of vigorous-intensity exercise, every week
- avoiding or limiting alcohol, and avoiding drinking more than one alcoholic drink per day (for females)
- eating a healthy diet with plenty of fruits and vegetables that is low in fat, red and processed meat, and added sugars
- considering nonhormonal contraceptive or menopausal treatment options
Additionally, for people who give birth, breastfeeding for several months or more after childbirth may help reduce breast cancer risk.
If people have an increased risk of breast cancer due to genetics or family history, they may want to consider:
- seeking genetic counseling and testing
- taking medications to reduce breast cancer risk
- undergoing preventive surgery
- receiving close observation to check for early signs of breast cancer
Breast cancer is one of the most common cancers and is the second most common cancer that affects females.
Treatment for breast cancer is highly effective and may lead to survival rates of
If people notice any symptoms of breast cancer or unusual changes to the breasts, they can contact a doctor for a checkup.
In many cases, an abnormal sign, such as a lump, is noncancerous and could indicate a cyst or infection, but it is important to find out the underlying cause.