Carcinoembryonic Antigen

CEA testing is covered for monitoring colorectal carcinoma at treatment decision points, for preoperative/postoperative assessment, and as an alternative tumor marker in certain lung and gastrointestinal cancers when a more specific marker is absent. For colorectal patients (initial stage II/III) where liver-metastasis resection would be considered, ASCO recommends postoperative CEA every 2–3 months for at least two years; for metastatic CEA-expressing solid tumors, measure at baseline and generally once per chemotherapy cycle to assess response. Testing frequency is limited (generally ≤ once per chemo cycle or every two months post-op), with allowance for more frequent testing when significant changes in CEA or clinical status suggest progression; in situ carcinoma testing is limited to one test (repeat once if abnormal).

"CEA testing is medically necessary for follow-up monitoring of patients with colorectal carcinoma at treatment decision-making points."