Which of the following is the most important tumor marker to diagnose carcinoma of ovary?

AIIMS Patna NO - 2020

Obstetrics & Gynaecology

Easy

Appeared in: AIIMS Patna NO - 2020

Explanation

CA-125 (Cancer Antigen 125) is the most widely used tumor marker for epithelial ovarian cancer, which accounts for about 90% of all ovarian malignancies.
While not used for general screening due to low specificity, it is crucial for evaluating suspicious pelvic masses, monitoring the effectiveness of therapy, and detecting cancer recurrence.
Serum CA-125 levels are elevated in approximately 80% of women with advanced epithelial ovarian cancer.
Its levels often correlate with the tumor burden, meaning higher levels can indicate a larger tumor or more widespread disease.

Option A: Serum human chorionic gonadotropin (hCG) is not a marker for the most common types of ovarian carcinoma. It is primarily associated with pregnancy and specific germ cell tumors.
Option C: Human placental lactogen (hPL) is a hormone related to pregnancy and placental function, not a tumor marker for cancer.
Option D: Serum alpha-fetoprotein (AFP) is associated with specific, less common ovarian tumors (yolk sac tumors) and is not the primary marker for the majority of ovarian carcinomas.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Tumor markers for ovarian carcinoma as background academic context rather than a clinical decision trigger.
A nurse's role includes educating patients that CA-125 is not a perfect test. It can be elevated in non-cancerous conditions like endometriosis, pelvic inflammatory disease, and even menstruation, which can cause patient anxiety.
Nurses are responsible for ensuring blood samples for CA-125 are drawn correctly and for tracking the trend of the results over time to report significant changes to the provider.
What if? If a premenopausal patient has a simple ovarian cyst on ultrasound and a slightly elevated CA-125, the next step is often watchful waiting and repeat testing, as benign conditions are a likely cause. In a postmenopausal patient, the same finding is more suspicious and warrants a referral to a gynecologic oncologist.

How to Approach the Question

First, identify the core of the question: it asks for the 'most important' tumor marker for 'carcinoma of ovary'. This implies you need to recall the primary, most common association.
Recall the different types of ovarian cancers. The most common is epithelial carcinoma.
Access your knowledge of common tumor markers. Associate each marker in the options with its primary cancer type.
Compare the options: hCG and AFP are for germ cell tumors, hPL is for pregnancy, and CA-125 is for epithelial ovarian cancer.
Conclude that since epithelial cancer is the most common ovarian malignancy, CA-125 is the 'most important' marker in this general context.

Concept Tested & Keywords

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