Long-term survival outcome after postoperative recurrence of non-small-cell lung cancer: who is 'cured' from postoperative recurrence?

OBJECTIVES: Since survival after postoperative non-small-cell lung cancer (NSCLC) recurrence is extremely poor, the long-term post-recurrence outcomes are not well understood. The purpose of this study was to evaluate the long-term post-recurrence outcomes and clarify who are possibly 'cured' in recent clinical practice. METHODS: We reviewed the medical records of 635 patients who developed postoperative recurrence until 2012 after R0 resection for pathological Stage IA-IIIA NSCLC between 1993 and 2006. Factors associated with post-recurrence survival (PRS) and the characteristics of the long-term (≥5 years) survivors were analysed retrospectively. RESULTS: The 5-year PRS rate of all 635 patients was 13%. Multivariable analysis revealed that female [hazard ratio (HR) = 0.78], adenocarcinoma (HR = 0.77), locoregional (only) recurrence (HR = 0.59) and longer recurrence-free survival (HR = 0.99) were favourably associated with PRS. A total of 51 patients achieved 5-year PRS; however, 32 (63%) were cancer-bearing patients in their fifth post-recurrent year who were mainly treated by epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI). Subsequent PRS curves for cancer-controlled and cancer-bearing groups were different (8-year PRS: 94% vs 31%, P = 0.003). Among 19 cancer-controlled patients in their fifth post-recurrent year, 17 (89%) patients initially received radical local therapy for their recurrence. CONCLUSIONS: Two-thirds of 5-year survivors after postoperative NSCLC recurrence had a cancer-bearing status and showed deteriorated subsequent survival. Curability of postoperative NSCLC recurrence should be evaluated in terms of the 'cancer-controlled' status, and 'cured' population is included in the patients who are 'cancer controlled' at the fifth post-recurrent year.