Ovarian Cancer Risk Factors After Age 40
Never having children (nulliparity) increases the risk for ovarian cancer after age 40, making option A the correct answer. 1, 2
Evidence-Based Risk Assessment
Nulliparity as a Risk Factor
- Nulliparity or older age at first birth (>35 years) confers an increased risk of ovarian cancer, as clearly stated in NCCN guidelines 1
- Women who have never had children lack the protective effect of pregnancy on ovarian tissue, which increases lifetime ovulatory cycles and associated cancer risk 3, 4
- The mechanism relates to "incessant ovulation" theory—more ovulatory cycles without interruption from pregnancy increases epithelial cell damage and repair cycles 3
Protective Factors (Incorrect Options)
Oral contraceptive use (Option B) is protective, not a risk factor:
- A 30% to 60% decreased risk of ovarian cancer is associated with oral contraceptive use 1
- This protective effect is well-established across multiple guidelines and represents one of the strongest modifiable protective factors 3, 4
Multiple pregnancies (Option C) reduce risk substantially:
- Younger age at pregnancy and first birth (≤25 years) confers a 30-60% decreased risk 1
- High gravidity (multiple pregnancies) is independently associated with reduced ovarian cancer risk 5
- Each full-term pregnancy provides cumulative protection 4
Prolonged lactation (Option D) is also protective:
- Breastfeeding is consistently identified as a protective factor against ovarian cancer 1, 2
- The protective mechanism involves hormonal changes and suppression of ovulation during lactation 3
Clinical Context for Age 40+
- Ovarian cancer risk increases steeply after age 40, with the median age at diagnosis being 61-63 years 6, 7
- More than 80% of ovarian cancer cases are diagnosed in women over 50 years of age 2, 6
- The incidence peaks at ages 65-75 years, making age itself a major risk factor 4
Additional Risk Factors to Consider
- Family history of breast or ovarian cancer (particularly first-degree relatives) 1
- BRCA1/2 mutations (15-45% lifetime risk with BRCA1, 10-20% with BRCA2) 6, 7
- Late age at menopause increases risk due to prolonged ovulatory exposure 5
- Infertility is associated with increased risk 5
The answer is A: Never having children represents the only risk-increasing factor among the options provided.