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

BACKGROUND: For early‐stage non‐small cell lung cancer (NSCLC), surgical resection is considered the most effective treatment strategy and curative treatment. Unfortunately, even after complete resection, almost half of all patients with stage I–IIIA NSCLC relapse and die. Although the possibility of a cure for postoperative recurrence of NSCLC is significantly low, the course of subsequent treatment can possibly affect overall survival (OS). Here, we examined the association of relapse‐free survival (RFS) and post‐progression survival (PPS) with OS in patients with postoperative recurrence of NSCLC. METHODS: We evaluated 128 patients with NSCLC who underwent complete resection between January 2007 and December 2018. The association between RFS and PPS on OS was examined at the patient level. RESULTS: Spearman's rank correlation and linear regression analyses revealed that PPS was strongly correlated with OS (r = 0.83, p < 0.05, R ( 2 ) = 0.72), whereas RFS was weakly associated with OS (r = 0.56, p < 0.05, R ( 2 ) = 0.37). Additionally, the performance status at relapse and administration of tyrosine kinase inhibitors were significantly correlated with PPS. CONCLUSIONS: PPS was significantly more strongly correlated with OS than was RFS in patients with postoperative recurrence of NSCLC. These results suggest that therapy following postoperative recurrence affects OS. Therefore, it is necessary to validate these promising results in a large prospective study.