Which laboratory test value is elevated in clients who smoke and can’t be used as a general indicator of cancer?
A. Acid phosphatase level
B. Serum calcitonin level
C. Alkaline phosphatase level
D. Carcinoembryonic antigen level
Correct Answer: D. Carcinoembryonic antigen level
In clients who smoke, the level of carcinoembryonic antigen is elevated. Therefore, it can’t be used as a general indicator of cancer. However, it is helpful in monitoring cancer treatment because the level usually falls to normal within 1 month if treatment is successful.
Option A: An elevated acid phosphatase level may indicate prostate cancer. Prostatic acid phosphatase is a non-specific phosphomonoesterase synthesized in prostate epithelial cells and its level proportionally increases with prostate cancer progression.
Option C: An elevated alkaline phosphatase level may reflect bone metastasis. When abnormal bone tissue is being formed by cancer cells, levels of alkaline phosphatase increase. Therefore, high levels of this enzyme could suggest that a patient has bone metastasis.
Option B: An elevated serum calcitonin level usually signals thyroid cancer. Calcitonin can be measured as a blood test to help diagnose medullary thyroid cancer and its level can indicate the amount of medullary thyroid cancer present before thyroid surgery.