What is the recommended screening protocol for ovarian cancer?

Ovarian Cancer Screening Recommendations

The U.S. Preventive Services Task Force (USPSTF) recommends against routine screening for ovarian cancer in asymptomatic women without known genetic mutations that increase risk of ovarian cancer, as the harms of screening outweigh the potential benefits. 1

For Average-Risk Women

• No routine screening is recommended for asymptomatic women at average risk 2, 1
• This includes:
  • No routine CA-125 testing
  • No routine transvaginal ultrasound
  • No routine bimanual pelvic examinations specifically for ovarian cancer screening

Evidence Against Screening in Average-Risk Women

• The PLCO Cancer Screening Trial showed no mortality benefit from screening with CA-125 and transvaginal ultrasound 2
• False positive rates are high (approximately 10% of screened women) 2
• Positive predictive value is very low (approximately 2%) 2
• Harms include:
  • Unnecessary surgeries (ratio of surgeries to screen-detected cancers approximately 20:1) 2
  • Major complications in nearly 21% of surgical procedures performed due to false-positive results 2
  • Psychological distress and anxiety in otherwise healthy women 2, 1

For High-Risk Women

For women at high risk (BRCA1/2 mutation carriers, Lynch syndrome, strong family history):

1. Genetic counseling and testing should be considered for women with:

   • Multiple relatives with ovarian cancer
   • Family history suggesting hereditary cancer syndromes

2. Screening options (though of uncertain benefit):

   • Transvaginal ultrasound every 6 months 2
   • Serum CA-125 determination 2
   • This screening should be performed in tertiary care/high-volume centers under structured protocols by experienced sonographers 2

3. Risk-reducing bilateral salpingo-oophorectomy (RRBSO) is the most effective approach:

   • Recommended for women with mutations in BRCA1/2, BRIP1, RAD51C, RAD51D or Lynch syndrome genes 2
   • Timing recommendations:
     • BRCA1 carriers: between ages 35-40 once childbearing is complete 2
     • BRCA2 carriers: between ages 40-45 2
   • Reduces risk of gynecological cancers by 80-90% 2
   • Decreases all-cause mortality by 77% 2

4. No screening is recommended after RRBSO 2

Limitations of Current Screening Methods

• Sensitivity of CA-125 (using threshold of 35 U/mL):

  • Approximately 80% in average-risk women 2
  • Reduced to 50% in high-risk women 2

• Sensitivity of transvaginal ultrasound:

  • Approximately 88% (95% CI, 47%-100%) 2
  • Specificity ranges from 97% to 99% 2

• Studies show screening may detect early-stage disease but fails to demonstrate mortality reduction 3, 4, 5

Common Pitfalls

1. Assuming screening is beneficial: Despite detecting some early-stage cancers, screening has not been shown to reduce mortality in average-risk women 2

2. Relying on symptoms alone: Most women with ovarian cancer present with advanced disease 2

3. Overestimating test accuracy: Both CA-125 and ultrasound have significant limitations in sensitivity and specificity 2, 5

4. Delaying risk-reducing surgery: For high-risk women, RRBSO is more effective than surveillance for preventing advanced ovarian cancer 4

5. Continuing screening after RRBSO: No evidence supports routine screening after risk-reducing surgery 2

In conclusion, the evidence strongly supports avoiding routine screening in average-risk women while offering risk-reducing surgery to high-risk women at appropriate ages. For high-risk women who decline or are not yet ready for surgery, screening with transvaginal ultrasound and CA-125 may be offered despite limited evidence of benefit.