Overview
Reading Tumor Markers Safely
A tumor marker value is evidence about a clinical question, not a cancer diagnosis.
A tumor-marker value is evidence about a clinical question, not a cancer diagnosis. The same result can mean something different depending on whether the patient has a confirmed malignancy, is being assessed for symptoms, is pregnant, has organ inflammation, or has recently received cancer treatment. The practical nurse connects the result to its purpose, checks factors that can distort interpretation, protects specimen integrity, compares results over time, and communicates findings that require follow-up. In Ontario, an RN or RPN may independently order tumor-marker laboratory tests listed in Schedule 22, such as PSA, CEA, CA 19-9, AFP, and β-hCG, only when practising within the extended class and the order is within competence. Outside that scope, the practical nurse follows an authorized order and employer policy. [1]