9 Breast Cancer Risk Factors Every Woman Should Know


breast cancer

Breast Cancer Risk Factors

Risk factors are the inherited or acquired factors that increase the chance of developing cancer in a person. Several epidemiological studies have suggested a number of genetic and environmental factors that may predispose to breast cancer. A knowledge about them helps us to make necessary lifestyle choices.

To further understand the disease in a better way, have a look at the video below where CancerBro meets Mrs. Brooks who is a 55 years old lady who has recently being diagnosed with breast cancer

Video explaining Breast Cancer risk factors in detail:

Video Transcript:

Yes CancerBro, can you please discuss the risk factors of breast cancer in detail for us to understand the disease better.

Mrs. Brooks had a lot of risk factors for breast cancer. The first one is the late age of marriage and first childbirth after 30 years of age, increases the risk of breast cancer.

Inadequate breastfeeding also increases the risk of the disease.

Early menarche, late menopause, and intake of hormonal replacement therapy after menopause, further aggravates the risk of breast cancer.

Previous history of breast cancer in family may also increase the risk in other family members.

Previous history of radiation exposure to chest wall, especially at a younger age, may also increase the risk of developing breast cancer.

Previous history of benign breast disorders, may further increase the risk.

A lot of cases of breast cancer can be prevented if the risk factors are kept in mind. 


risk factors

Risk factors for breast cancer Explained



Older age women are generally at increased risk of developing breast cancer. About 70% of all the incidences of breast cancer are observed in women older than 55 years of age.

Early menarche/late menopause

Early menarche - late menopause

Commencement of menstrual cycles (menarche) at an early age or cessation of menstrual cycles (menopause) at a later age than normal have been reported to elevate the risk of developing breast cancer. The increased risk is postulated to be related to the longer duration of exposure to female sex hormones, estrogen, and progesterone.

Delayed marriage or childbirth

Delayed marriage or childbirth

It has been reported that women who get married and have children by the age of 26 years are generally at lower risk of developing breast cancer. While women who got married at a later age and have pregnancy after 35 years of age or who never have had a full-term pregnancy are at increased risk of developing breast cancer.

Personal History

Females with a personal history of breast cancer or a benign breast disease, for example (e.g.), papilloma, atypical hyperplasia, or lobular carcinoma in situ are generally at higher risk of developing breast cancer.

History of breast cancer increases the risk of developing an invasive breast cancer in the contralateral breast. For in situ lesions, the 10 year risk of developing a contralateral invasive breast cancer is 5 percent. In women with invasive breast cancer, the risk of developing contralateral breast cancer is 1 and 0.5 percent per year for premenopausal and postmenopausal women, respectively.

Family history

Family history

Individual with a history of breast, ovary and certain other cancers in close relatives are considered to be at increased risk of developing breast cancer.

Genetic alterations

Genetic Cancer Predisposition Syndromes

Many inherited genetic alterations have been reported to be associated with a high incidence rate of breast cancer, for example (e.g.), a mutation in the following genes have been reported to increase the risk of breast cancer: BRCA1,BRCA2, ATM, TP53, ERBB2, CHEK2, PTEN, CDH1, STK11, PALB2 and many other.

Dense Breast Tissue

Dense Breast Tissue

It has been observed that females with dense breast tissue (less fatty tissue and more glandular and fibrous tissue) are at about 1.5 to 2 times higher risk of developing breast cancer compared to females with normal breast tissue.

Prolonged hormonal replacement therapy

Prolonged hormonal replacement therapy

Women who are using or who have used hormone replacement therapy (HRT) after menopause for many years are generally at higher risk of developing breast cancer.

History of Radiation therapy to Breast or Chest

Exposure to radiation to chest or breast

Women with a history of radiation treatment to their breast or chest, especially at a younger age, are at increased risk of developing breast cancer.



Overweight or obese females are at higher risk of developing breast cancer which may be due to the higher exposure to estrogen produced in the fat tissue after menopause.


excessive alcohol consumption

Excessive alcohol consumption has been reported to increase the risk of breast cancer and the risk increases with the increase in the amount of alcohol consumed.

Limited physical activity and prolonged use of oral contraceptives have also been linked to increased incidence of breast cancer.

What are the Modifiable and Non-modifiable risk factors for breast cancer?


  1. Age
  2. Genetic factors – mutations in BRCA1 or BRCA2; 50-60% of women inheriting a BRCA1 mutation from either parent will have breast cancer by age 70
  3. Family history of breast cancer (not related to BRCA mutations)
  4. Personal history of hyperplastic breast disease
  5. Race: incidence is higher in Caucasian compared with African-American, Hispanic or Asian women
  6. Radiation treatment: chest irradiation as a child/young woman can significantly increase risk of developing breast cancer
  7. Menstrual history: early menarche (<12 yr) or late menopause (>50yr) has some association with increased risk. Also nulliparous, or first childbirth at >30 yrs.


  1. Oral contraceptives 
  2. Hormone replacement therapy – >5 years of therapy with combined estrogen and progesterone may increase risk
  3. Not breast feeding
  4. Diet and obesity; physical activity
  5. Smoking 
  6. Alcohol – 2-5 drinks/day can increase risk x 1.5 over non-drinkers.

Breast cancer screening is recommended for every woman, and even earlier if there are risk factors present for breast cancer. Also one should know about the symptoms of breast cancer to detect the disease at an earlier stage.


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