Survival Prediction and Adjuvant Chemotherapy Based on Tumor Marker for Stage IB Lung Adenocarcinoma

We aimed to find out the prognosis of stage IB invasive lung adenocarcinoma according to perioperative tumor markers (TMs), especially carcinoembryonic antigen (CEA), and to determine whether TMs could guide adjuvant chemotherapy.

Stage IB adenocarcinoma patients were selected from 2 medical centers in Shanghai between January 2007 and December 2013. Perioperative TMs, including preoperative and postoperative TMs, were stratified into normal level, CEA normal, and CEA elevated. Propensity score matching was analyzed for eliminating variable differences between chemotherapy and observation groups. Univariable and multivariable Cox regression analyses were conducted to discover the prognostic independent risk factors. Kaplan-Meier curves were plotted and assessed by the log-rank test. Subgroup analysis was performed to investigate chemotherapy benefit according to postoperative TMs.

Postoperative CEA elevated (hazard ratio [HR], 6.783, 95% confidence interval [CI], 2.534-18.162; P < .001), CEA normal (HR, 3.332; 95% CI, 1.553-7.147; P = .002), and older age were independently correlated with worse recurrence; however, only postoperative CEA elevated (HR, 11.546; 95% CI, 3.854-34.588; P < .001) and CEA normal (HR, 4.389; 95% CI, 1.566-12.300; P = .005) independently influenced survival outcome. Chemotherapy showed limited recurrence and survival benefit among the primary cohort. In subgroup analysis, chemotherapy even shortened survival outcome when postoperative TMs were normal (HR, 8.870; 95% CI, 1.134-69.381; P = .038).

Postoperative rather than preoperative CEA normal and CEA elevated were 2 independent risk indicators for poorer clinical outcome. Chemotherapy failed to improve clinical outcomes when postoperative TMs were elevated. Importantly, chemotherapy could not be recommended when postoperative TMs were at a normal level.