A simplified scoring system for predicting treatment response in limited-stage small-cell lung cancer (EAST score).

Abstract

Aims: This study aimed at developing a scoring system (EAST score) to predict recurrence after chemoradiotherapy in limited-stage small-cell lung cancer (LS-SCLC).

Patients & methods: Treatment-naïve LS-SCLC patients receiving concurrent chemoradiotherapy (CCRT) (N = 234) or sequential chemoradiotherapy (N = 53) were retrospectively reviewed. Using data from CCRT population, clinical and radiological variables associated with disease progression were identified. Selected variables were assigned numerical scores based on their estimated hazard ratios (HRs), and the EAST score was established.

Results: EAST score incorporated N3 disease and serum biomarkers (lactate dehydrogenase, pro-gastrin-releasing peptide, and cytokeratin-19 fragment). In the CCRT population, progression-free survival (PFS) was significantly shorter in the high-risk group (EAST score ≥ 2) than the low-risk group (EAST score ≤ 1) (median, 9.4 months vs. 20.6 months; HR [95% confidence interval (CI)], 2.09 [1.50-2.91]). As for the model performance, the 1- and 2-year area under the curve values for PFS were 0.68 and 0.65, respectively. Overall survival was also shorter in the high-risk group (HR [95% CI], 1.49 [1.02-2.16]). Similar trends were observed in the sequential chemoradiotherapy population (HR for PFS [95% CI], 2.43 [1.07-5.53]).

Conclusions: EAST score effectively predicts recurrence risk in LS-SCLC, demonstrating the necessity for developing new treatment strategies for high-risk patients.