Risk and Protective Factors

Risk Factors1 2 3

  • Older age (60 and older).
  • Family health history of breast, ovarian, colorectal, or other cancer.
  • Carries a BRCA1 (BReast CAncer susceptibility gene) mutation (lifetime risk of up to 40%).
  • Carries a BRCA2 gene mutation (lifetime risk of 11% to 17%).
  • Lynch syndrome.
  • Infertility.
  • Endometriosis.

Protective Factors1 2 3

  • Oral contraceptives (more than 10 years of use reduces risk by 50%). Reduced risk is found in women taking oral contraceptive pills (OCPs) for contraceptive purposes. OCPs increase risk for breast and cervical cancer.
  • Breastfeeding (20% reduction for each year).
  • Parity (25% reduction for first birth, 20% for subsequent births).
  • Salpingo-oophorectomy (more than 90% reduction).
  • Tubal ligation (20% to 50% reduction).


1CDC. Ovarian cancer.

2DeVita VT Jr, Lawrence TS, Rosenberg SA, DePinho RA, and Weinberg RA. Devita, Hellman, and Rosenberg’s Cancer: Principles and Practice of Oncology (8th ed.). Philadelphia: Lippincott Williams and Wilkins, 2008.

3Schottenfeld D, Fraumeni J Jr. Cancer Epidemiology and Prevention (3rd ed.). Eastbourne, UK; WB Saunders Co., 1982.

Knowledge Check

Answer the question on your own and check your answer.

Answer: Increasing age, family health history, infertility, and endometriosis.

Page last reviewed: September 14, 2015