Long-term results in patients with pathological complete response after induction radiochemotherapy followed by surgery for locally advanced non-small-cell lung cancer

Abstract

The outcome of locally advanced non-small-cell lung cancer (NSCLC) patients with pathological complete response (pCR)-pT0N0 -after induction chemoradiotherapy (IT) followed by surgery has, to date, only rarely been investigated. The long-term results in this highly selected subset of patients were evaluated and reported here to identify any predictive factors associated with prognosis. From January 1992 to December 2009, 195 consecutive locally advanced (T1-T4/N0-2/M0) NSCLC patients underwent IT, and after clinical restaging, 137 were operated upon with radical intent. Among these, 37 (19% of the overall and 27% of the surgical cohort) showed a pCR status and were included in this retrospective analysis. Survival rates and prognostic factors were analysed by the Kaplan-Meier, the log-rank and Cox regression analyses. The mean age and male/female ratio were 61.9 ± 9.8 years and 33/4, respectively. Before starting IT, the clinical staging was IIb in 2 (5%) patients, IIIa in 20 (54%) and IIIb in 15 (41%). Morbidity and 30-day mortality rates were 27 and 3%, respectively. The overall 3- and 5-year long-term survivals (LTSs) and disease-free survival (DFS) were 67 and 64% and 68 and 71%, respectively. Overall, 17 patients (46%) experienced a recurrence, occurring more frequently in a distant site (32%) than locally (19%). The analysis of the 5-year LTS suggests that (i) the initial single N2 station involvement (P = 0.010); (ii) the resection to a lesser extent than pneumonectomy (P = 0.005) and (iii) the adjuvant therapy (P = 0.005) are all positive prognostic factors. In particular, a 5-year hazard ratio of 8.21 (95% confidence interval 2.16-31.16, P = 0.002) was estimated by Cox regression analysis for subjects who did not undergo adjuvant therapy vs those who did. After induction radiochemotherapy followed by surgery in locally advanced NSCLC, a pCR is achieved in a remarkable proportion of cases (27% in our experience). In such patients, a rewarding LTS (64% at 5 years) could be expected, especially when a single N2 station is involved at diagnosis or when an adjuvant treatment is administered. Nevertheless, recurrences after surgery are quite common (46%) and this evidence deserves further investigations and deeper analysis.