From the Guidelines
The initial lab test for a postmenopausal female with ovarian enlargement or cyst is CA-125 (Cancer Antigen 125). This blood test measures the level of the CA-125 protein, which is often elevated in women with ovarian cancer 1. While CA-125 should be ordered promptly upon discovery of an ovarian mass in a postmenopausal woman, it's essential to understand that this test has limitations. CA-125 can be elevated in various benign conditions, including endometriosis, fibroids, pelvic inflammatory disease, and even during menstruation in premenopausal women, which is why it's most useful in the postmenopausal population.
Some key points to consider when interpreting CA-125 results include:
- Normal CA-125 levels are generally below 35 U/mL, though this can vary by laboratory
- Elevated CA-125 levels in a postmenopausal woman with an ovarian mass significantly increase the suspicion for malignancy
- The test should be interpreted alongside imaging findings (typically transvaginal ultrasound) and clinical presentation
- Additional workup may include comprehensive metabolic panel, CBC, and other tumor markers depending on clinical suspicion
It's also important to note that the American College of Obstetricians and Gynecologists/Society of Gynecologic Oncology (ACOG/SGO) criteria recommend referral for postmenopausal women with elevated CA-125, among other factors 1. In terms of imaging, the American College of Radiology recommends transvaginal ultrasound as part of the initial imaging for postmenopausal patients with a clinically suspected adnexal mass and no acute symptoms 1.
Overall, CA-125 is a crucial initial lab test for postmenopausal females with ovarian enlargement or cyst, and its results should be considered in conjunction with clinical presentation, imaging findings, and other diagnostic tests to guide further management.
From the Research
Initial Lab Tests for Ovarian Enlargement or Cyst in Postmenopausal Females
The initial lab tests for a postmenopausal female with ovarian enlargement or cyst include:
- Serum CA 125 assay, which is the most reliable serum marker for ovarian carcinoma 2
- Other tumor-associated antigens such as CA 19.9, CA 15.3, and TAG.72 may also be detected in tissue and serum samples from patients with ovarian carcinoma 2
- Serum alphaFP and betaHCG are useful in the preoperative evaluation and management of nondysgerminomatous ovarian germ cell tumors 2
- Elevated serum inhibin levels can be detected in patients with granulosa cell tumors of the ovary 2
Reference Ranges for CA 125 in Postmenopausal Women
The reference ranges for CA 125 in postmenopausal women are:
- Upper limit of normal: 35 U/mL for women without vaginal bleeding and 20 U/mL for those with vaginal bleeding 3
- For postmenopausal women with unilocular ovarian cysts less than 50 mm in diameter and normal serum CA 125 levels, expectant management may be considered 4
Prognostic Value of CA 125 in Borderline Ovarian Tumors
CA 125 may be indicative of a poor prognosis in borderline ovarian tumors, even with slight increases in CA 125 levels 5