DiM: Prognostic Score for Second- or Further-line Immunotherapy in Advanced Non–Small-Cell Lung Cancer: An External Validation

Background: Other than the programmed cell death ligand 1 (PD-L1) value, oncologists have only the clinical characteristics of patients with advanced non–small-cell lung cancer (aNSCLC) to determine candidates for immunotherapy. A clinical prognostic score composed of the Eastern Cooperative Oncology Group performance status, sex, histologic type, stage, platinum-based first-line therapy, and response to first-line therapy has categorized 3 prognostic groups for patients undergoing second-line chemotherapy. We sought to validate the same score for patients with aNSCLC treated with second- or further-line immunotherapy. Materials and Methods: We collected data from 2 Italian centers. A score was generated to divide patients into 3 prognostic groups: best, score < 5; intermediate, score 5 to 9; and worst, score > 9. Overall survival (OS) and progression-free survival (PFS) were the endpoints. Results: A total of 347 patients were included for analysis. Their median age was 66 years (range, 30-88 years), most were aged < 70 years (67.5%), 70.7% were men, 79.5% were smokers, and 74.6% had had adenocarcinoma. The Eastern Cooperative Oncology Group performance status was 0 for 23%, 1 for 54.5%, and 2 for 22.5%. Of the 347 patients, 28% were in the best prognosis, 51% in the intermediate, and 21% in the worst prognosis group, respectively. The median OS was 18.0 months for the best, 8.5 months for the intermediate (hazard ratio [HR] vs. best, 1.83; 95% confidence interval [CI], 1.35-2.47; P < .001) and 2.6 months for worst (HR vs. best, 5.77; 95% CI, 3.99-8.33; P < .001) group. The median PFS was 3.4 months for the best, 3.7 months for the intermediate (HR vs. best, 1.35; 95% CI, 1.03-1.77; P = .032), and 1.9 months for the worst (HR vs. best, 2.51; 95% CI, 1.80-3.50; P < .001) group. Conclusions: The prognostic score was able to predict the outcomes of patients with aNSCLC who had received immunotherapy. The worst category showed a dismal life expectancy and probably would not benefit from active systemic therapy. Thus, for these patients, best supportive care could be the best choice.