Post-Progression Survival Is Strongly Associated with Overall Survival in Patients Exhibiting Postoperative Relapse of Non-Small-Cell Lung Cancer Harboring Sensitizing EGFR Mutations

Abstract

Background and Objective: Patients with advanced non-small-cell lung cancer (NSCLC) harboring sensitizing epidermal growth factor receptor (EGFR) mutations show a good response to EGFR-tyrosine kinase inhibitors (EGFR-TKIs). The subsequent treatments influence the evaluability of the efficacy of front-line therapy on overall survival (OS). Consequently, we evaluated the associations of relapse-free survival (RFS) and post-progression survival (PPS) with OS in patients who exhibited postoperative relapse of EGFR-mutated NSCLC. Materials and Methods: We analyzed the data of 35 patients with EGFR-mutated NSCLC who underwent complete resection between January 2007 and June 2019. The correlations of RFS and PPS with OS were evaluated at the individual patient level. Results: Linear regression and Spearman’s rank correlation analyses demonstrated that the PPS highly correlated with OS (r = 0.91, p < 0.05, R2 = 0.85), whereas the RFS weakly associated with OS (r = 0.36, p < 0.05, R2 = 0.25). Age and performance status at relapse were significantly associated with PPS. Conclusion: Overall, PPS was more strongly and significantly associated with OS than RFS. These results suggest that the OS of our cohort may be affected by treatments, besides postoperative relapse. However, larger-scale prospective studies are needed to confirm these results.

Course of postoperative relapse in non‐small cell lung cancer is strongly associated with post‐progression survival

“…Previous reports have suggested that OS correlates better with PPS than RFS in patients harboring EGFR ‐positive NSCLC who have undergone complete resection. 26 There is a report of significant disease‐free survival (DFS) prolongation with the administration of osimertinib as postoperative adjuvant chemotherapy in EGFR ‐mutated NSCLC. 27 However, if PPS is shown to alter OS in patients with postoperative recurrence, it is possible that DFS prolongation with adjuvant EGFR‐TKIs does not affect OS.…”