Pre-operative carcino-embryonic antigen prognosticates early disease-free survival following curative surgery for non-small cell lung cancer

INTRODUCTION: Serum carcinoembryonic antigen (CEA) is prognostic for recurrence and survival in treated NSCLC. This prospective observational study evaluated CEA as a prognostic or surveillance biomarker in resectable early NSCLC.

MATERIALS AND METHODS: 18 patients with histologically confirmed early NSCLC (stage I-IIIA) were recruited from October 2019 to January 2021. The serum CEA was measured pre-operatively, and then at 6, 12, 18 and 24 months post-operatively, in conjunction with routine CT and/or CT-PET surveillance scans.

RESULTS: All patients had a curative R0 anatomical resection (lobectomy) with concurrent systematic mediastinal nodal dissection via a uniportal minimally invasive approach under single lung ventilation general anaesthesia. There was no operative, in-hospital or 30-day mortality. 7 patients (39%) had an elevated pre-operative baseline CEA level > 5.0ng/ml. The mean number of nodes sampled intraoperatively was 15. At median follow-up of 42 months, 11/18 (61.1%) patients were recurrence-free. There were no deaths and two recurrences (18.2%) amongst patients with a CEA < 5 (n=11). In the CEA > 5 subgroup (n=7), there were two deaths (28.5%) and 5/7 (71.4%) patients had a radiological recurrence. There was no difference in overall survival however disease-free survival (DFS) was significantly inferior in patients with a baseline CEA > 5. Median DFS was not reached in patients with CEA < 5 and 18 months in those with an elevated CEA > 5 (p<0.001) Conclusion: Almost 40% of local NSCLC patients had an elevated baseline CEA suggesting this is a useful prognostic and surveillance biomarker to incorporate in the routine work-up for any newly diagnosed NSCLC. Despite curative R0 resection and extensive intra-operative mediastinal lymph node sampling, an elevated pre-operative CEA was associated with a significantly reduced DFS and may be a surrogate for more aggressive tumour biology. Such patients will benefit from meticulous post resection surveillance and adjuvant therapy beyond conventional TNM criteria.