BACKGROUND: The cutoff value of preoperative serum carcinoembryonic antigen (CEA) levels has not been investigated using appropriate subgroup analyses for non-small cell lung carcinoma (NSCLC). This study was undertaken to determine whether the most predictive preoperative CEA level for risk of recurrence differs according to histological type, and how smoking status influences predictive values in Stage I NSCLC. METHODS: Subjects comprised Stage I NSCLC patients [141 patients with adenocarcinoma (ADC) and 36 with squamous cell carcinoma (SCC)]. RESULTS: In patients with Stage I ADC, recurrence-free survival (RFS) differed most significantly at a preoperative CEA level of 2.5 ng/ml, regardless of smoking status. Cases with preoperative CEA >2.5 ng/ml correlated with male sex, high maximum standard uptake value on (18) F-fluorodeoxyglucose positron emission tomography, poorer histopathological grade, lymphatic invasion, and smoking status. Importantly, preoperative CEA >2.5 ng/ml was identified as an independent risk factor for recurrence (P = 0.0015). Conversely, in patients with SCC, a preoperative CEA level of 3.0 ng/ml was the most predictive threshold. CONCLUSIONS: Thresholds of preoperative CEA should be considered when predicting risk of relapse, even if these levels are within normal limits, as optimal cutoff levels may vary according to histological type.
BACKGROUND: The cutoff value of preoperative serum carcinoembryonic antigen (CEA) levels has not been investigated using appropriate subgroup analyses for non-small cell lung carcinoma (NSCLC). This study was undertaken to determine whether the most predictive preoperative CEA level for risk of recurrence differs according to histological type, and how smoking status influences predictive values in Stage I NSCLC. METHODS: Subjects comprised Stage I NSCLCpatients [141 patients with adenocarcinoma (ADC) and 36 with squamous cell carcinoma (SCC)]. RESULTS: In patients with Stage I ADC, recurrence-free survival (RFS) differed most significantly at a preoperative CEA level of 2.5 ng/ml, regardless of smoking status. Cases with preoperative CEA >2.5 ng/ml correlated with male sex, high maximum standard uptake value on (18) F-fluorodeoxyglucose positron emission tomography, poorer histopathological grade, lymphatic invasion, and smoking status. Importantly, preoperative CEA >2.5 ng/ml was identified as an independent risk factor for recurrence (P = 0.0015). Conversely, in patients with SCC, a preoperative CEA level of 3.0 ng/ml was the most predictive threshold. CONCLUSIONS: Thresholds of preoperative CEA should be considered when predicting risk of relapse, even if these levels are within normal limits, as optimal cutoff levels may vary according to histological type.