Carcinoembryonic antigen (CEA) is a prognostic marker for early-stage non-small cell lung cancer (NSCLC), and cryoablation is a new therapeutic alternative for lung cancer. We determined whether cryoablation-induced changes in serum CEA levels correlated with tumor type (adenocarcinoma or squamous carcinoma) and treatment type (comprehensive therapy [cryoablation of all intra- and extrapulmonary tumors] or palliative therapy [cryoablation of only extrapulmonary tumors]) in patients with metastatic NSCLC, and assessed whether pre-treatment CEA levels predicted overall survival (OS). We retrospectively reviewed the clinical data of 88 patients with metastatic NSCLC who underwent comprehensive (62 patients) or palliative (26 patients) therapy. Pre- and post-cryoablation serum CEA levels and overall survival were determined for all patients. Cryoablation significantly reduced CEA levels in adenocarcinoma, but not squamous carcinoma, patients. Among adenocarcinoma patients, the cryoablation-induced reduction in CEA levels was significantly greater after comprehensive treatment than after palliative treatment; the OS of patients under comprehensive cryoablation was longer than those under palliative treatment. Among adenocarcinoma patients receiving comprehensive cryoablation, OS was significantly longer in those with normal pre-treatment serum CEA levels than in those with abnormal pre-treatment serum CEA levels. Pretreatment level and change of serum CEA can be a good indicator for therapeutic effects and OS in metastatic NSCLC patients under percutaneous cryosurgery.
Keywords: Cryosurgery; carcinoembryonic antigen; metastatic non-small cell lung cancer.