Font Size

Mammogram (cont.)

What are the risk factors for breast cancer?

  • Age: Risk increases with age. Seventy-seven percent of women with breast cancer are older than 50 years at diagnosis; women aged 20 to 29 years represent less than 0.4% of the total.
  • Genetics: Around 5% to 10% of breast cancers result from inherited mutations. Sixty to seventy percent of women with mutations of BRCA1 and BRCA2 genes will develop a breast cancer by age 70 years. Also mutations of the p53 gene increase the risk. In addition, some families without gene mutations have multiple family members in multiple generations with breast cancer. Women from such families are at an increased risk for developing breast cancer.
  • Family history: Women who have a first-degree relative (sister, mother, or daughter) with breast cancer double the risk, and those who have two affected relatives multiply the risk three times.
  • Medical history: A previous breast cancer increases risk (3 to 4 times) of developing a cancer in the same breast or in the opposite side.
  • Fibrocystic breast disease does not increase the risk, but a type of microscopic change known as atypical hyperplasia of the breast tissue does confer an 3 to 5 fold increased risk.
  • Previous therapeutic irradiations always cause a meaningful increase in risk.
  • Menstrual cycles: Early onset of menstruation (before age 12 years) or late menopause (older than 55 years) or both slightly increases risk.
  • Pregnancies: No pregnancy, or first pregnancy after age 30 years, increases risk moderately.
  • Hormone therapy (HT) for menopause: Combination hormone therapy with estrogen and progesterone increases the risk of breast cancer, but the risk is returns to normal five years after stopping the therapy. HT with estrogen alone does not appear to increase risk.
  • Oral contraceptive use may slightly increase breast cancer risk, though this remains controversial.
  • Breastfeeding: According to some studies, breastfeeding for 1 1/2-2 years reduces risk.
  • Alcohol: High consumption of alcoholic beverages increases risk.
  • Smoking: There is some evidence that smoking may increase risk.
  • Obesity: Being overweight increases risk.
  • Physical activity: Movement and daily activity reduce risk and are therefore useful.

REFERENCES: Mammograms.

Siddique, M. N. MBBS. "Mammogram Guidelines." Dec 12, 2014.

Dongola, N. MD. "Mammography in Breast Cancer." Medscape. May 19, 2015.

American Cancer Society. "American Cancer Society Releases New Breast Cancer Guideline." Oct 20, 2015.

Medically Reviewed by a Doctor on 10/23/2015

Must Read Articles Related to Mammogram

Breast Cancer
Breast Cancer Breast cancer is the second leading cause of cancer in women. Symptoms and signs of breast cancer include breast lumps, nipple discharge or inversion, or change...learn more >>
Breast Lumps and Pain
Breast Lumps and Pain Breast changes are common. From the time a girl begins to develop breasts and begins menstruating and throughout life, women may experience various kinds of bre...learn more >>
Breast Self-Exam
Breast Self-Exam Monthly breast self-examinations (BSE) have not been shown to reduce the risk of dying from breast cancer. However, a monthly breast self-exam is important for ...learn more >>

Patient Comments & Reviews

The eMedicineHealth doctors ask about Mammogram:

Mammogram - Experience

Please share your experience with mammography.

Read What Your Physician is Reading on Medscape

Mammography - Computer-Aided Detection »

Computer-aided detection (CAD) for mammography is a new and evolving topic in the realm of breast radiology.

Read More on Medscape Reference »

Medical Dictionary