From the Guidelines
The gold standard initial screening tool for ovarian cancer is transvaginal ultrasound (TVUS) combined with the CA-125 blood test. Transvaginal ultrasound provides detailed images of the ovaries, allowing visualization of masses or abnormalities, while the CA-125 blood test measures levels of a protein that can be elevated in ovarian cancer 1. However, it's essential to understand that these are not perfect screening tools for the general population. CA-125 can be elevated in many non-cancerous conditions, including endometriosis, fibroids, and even menstruation, leading to false positives. Additionally, early-stage ovarian cancers may not cause CA-125 elevation. These tests are most useful when used together in women with symptoms or risk factors for ovarian cancer, such as persistent bloating, pelvic pain, difficulty eating, or frequent urination, or those with strong family histories of ovarian or breast cancer 1.
Some key points to consider:
- The specificity of the CA-125 test is 98.5% for women over 50 years but lower (94.5%) for those under 50 1.
- Transvaginal ultrasonography is often included among the procedures for the evaluation of a pelvic mass, and features highly suggestive of advanced ovarian cancer include the presence of a complex ovarian mass, ascites, or evidence of peritoneal metastases 1.
- The use of multimodal screening (serum CA-125 measurement and ultrasound imaging) for early detection of ovarian cancer seems to be effective, but it is not yet considered the gold standard for early detection 1.
- Other imaging techniques, such as magnetic resonance imaging (MRI) or positron emission tomography (PET), may provide additional information but are not routinely necessary in preoperative evaluation 1.
It's crucial to weigh the benefits and harms of screening for ovarian cancer, especially in asymptomatic, average-risk women. The US Preventive Services Task Force (USPSTF) recommends against screening for ovarian cancer in women who are not at high risk 1. However, for women at high risk, such as those with a strong family history or genetic mutations (e.g., BRCA1), screening with transvaginal ultrasound and CA-125 may be considered 1.
In real-life clinical practice, it's essential to consider the individual patient's risk factors, symptoms, and medical history when deciding on the appropriate screening approach. The combination of transvaginal ultrasound and CA-125 blood test is the most recommended initial screening tool for ovarian cancer, especially in women with symptoms or risk factors for the disease 1.
From the Research
Ovarian Cancer Screening Tools
- The gold standard initial diagnosis screening tool for ovarian cancer is not clearly established, but current tests used in diagnosis include the CA-125 blood test and transvaginal ultrasound 2, 3.
- Transvaginal ultrasound (TVU) is the primary modality for assessment of ovarian tumors, and standardized terminology is critical for optimal assessment of the risk of malignancy in an ovarian tumor 4.
- A multimodal approach of screening for ovarian cancer using transvaginal sonography in women with an elevated CA-125 may prove beneficial and cost-effective 4, 5.
Effectiveness of Screening Tools
- The sensitivity, specificity, positive and negative predictive values (PPV and NPV) of the combination of CA-125 and TVU were the highest (40%, 99%, 40% and 99%) in one study 2.
- The screening sensitivity was 70%, with 73% for BRCA carriers, in another study 5.
- However, most prospective trials have not demonstrated conclusively a reduction in mortality from ovarian cancer both in the screened general or high-risk population 6.