From the Guidelines
Elevated Cancer Antigen 125 (CA 125) levels with normal Carcinoembryonic Antigen (CEA) levels are highly suggestive of ovarian cancer, particularly in postmenopausal women or those with a high risk of ovarian cancer.
Key Points
- Elevated CA 125 levels are not specific to ovarian cancer and may be elevated in non-gynaecological malignancies and benign conditions, such as endometriosis and ovarian cysts 1.
- A high CA 125/CEA ratio (≥25) can help distinguish primary mucinous ovarian tumors from gastrointestinal metastasis 1.
- Measuring serum CEA and CA 19-9 levels in addition to CA 125 may help identify the primary site of the tumor 1.
- Transvaginal ultrasonography and computed tomography (CT) of the thorax, abdomen, and pelvis are recommended imaging investigations for women with suspected ovarian cancer 1.
- A definitive diagnosis of ovarian cancer requires pathological examination of tumor samples from either a diagnostic biopsy or a surgical specimen 1.
Clinical Implications
- Elevated CA 125 levels should be interpreted with caution, considering the patient's clinical presentation, medical history, and other diagnostic test results 1.
- A normal CEA level does not rule out ovarian cancer, as CEA is not a specific marker for ovarian cancer 1.
- Further diagnostic testing, such as endoscopy or colonoscopy, may be warranted if the CA 125/CEA ratio is ≤25 or if there are suspicions of a gastrointestinal primary tumor 1.
From the Research
Significance of Elevated CA 125 Levels with Normal CEA Levels
- Elevated CA 125 levels are often associated with ovarian cancer, particularly serous cystadenocarcinoma 2
- CA 125 levels can also be elevated in non-malignant conditions such as endometriosis and early stages of pregnancy, but these cases typically do not show extremely high CA 125 values 2
- A study found that an elevated CA 125 level can signal malignancies other than ovarian cancer, including breast and lung cancer 3
- In patients with epithelial ovarian cancer, a progressively rising serum CA-125 level within the normal range can indicate tumor recurrence 4
Differentiation between Malignant and Benign Ovarian Tumors
- Elevated CA-125 levels cannot differentiate between malignant and benign ovarian tumors on their own 5
- Proteomic analysis of serum from women with elevated CA-125 can identify predictive proteins to differentiate between malignant and benign ovarian tumors 5
- A novel protein, apolipoprotein A-4 (APOA4), has been identified as a potential marker for malignant tumor differentiation in the serum of women with elevated CA-125 5
Correlation with Cancer Development and Progression
- The levels of serum CA125, HE4, and CEA are closely related to the development and progression of epithelial ovarian cancer 6
- Combined detection of CA125, HE4, and CEA is significant for early diagnosis, disease development monitoring, and prognosis evaluation of epithelial ovarian cancer 6
- Elevated CA 125 levels with normal CEA levels may still indicate ovarian cancer or other malignancies, and further investigation is necessary to determine the cause of the elevated CA 125 levels 2, 3, 6