Serum tumor markers are not used for initial diagnosis but later used for which purpose?

Serum tumor markers are not used for initial diagnosis but later used for which purpose?

• A. Screening
• B. Treatment response
• C. Prognosis
• D. Genetic testing

Answer: (B)

The main idea here is that serum tumor markers are used to track what the disease is doing over time, not to diagnose or screen for cancer. In breast and other cancers, markers like CA 15-3 or CEA are measured serially during and after treatment. If the marker level falls with therapy, that suggests the tumor is responding; if it rises or climbs during follow-up, it can indicate progression or recurrence, prompting further tests or changes in management. They aren’t reliable for screening because they lack sufficient sensitivity and specificity to detect cancer in asymptomatic individuals. Genetic testing, on the other hand, uses DNA-based analyses rather than serum markers. While markers can provide some prognostic clues in advanced disease, their primary and most useful role is monitoring treatment response.

The main idea here is that serum tumor markers are used to track what the disease is doing over time, not to diagnose or screen for cancer. In breast and other cancers, markers like CA 15-3 or CEA are measured serially during and after treatment. If the marker level falls with therapy, that suggests the tumor is responding; if it rises or climbs during follow-up, it can indicate progression or recurrence, prompting further tests or changes in management. They aren’t reliable for screening because they lack sufficient sensitivity and specificity to detect cancer in asymptomatic individuals. Genetic testing, on the other hand, uses DNA-based analyses rather than serum markers. While markers can provide some prognostic clues in advanced disease, their primary and most useful role is monitoring treatment response.