Outcome: overall survival, cause-specific survival, disease-free survival and freedom from recurrence
The number of events for survival analyses (n = 152) and analyses of FFR (n = 115) is indicated in Fig. 1 (number of events for the respective subgroup analyses is indicated in Figs 2 and 3). OS of the entire patient cohort at 1, 3, 5 and 10 years was 96.4%, 91.0%, 87.2% and 62.7%, respectively. Accordingly, DFS, CSS and FFR were calculated: DFS: 84.3%, 60.9%, 44.9% and 15.2%; CSS: 97.8%, 94.9%, 92.3% and 79.7%; FFR (n = 115) at 1, 3, 5 and 10 years was 83.1%, 57.9%, 43.0% and 22.2%, respectively (Fig. 3).
Figure 3  Survival analysis: entire patient cohort. Overall survival (A), disease-free survival (B), cause-specific survival (C) and freedom from recurrence (D). Analysis of OS at 3, 5 and 10 years revealed statistically significant differences between primary pleural surgery and surgery for pleural recurrence (P = 0.028, P = 0.023, P = 0.027, respectively). Comparably, the analysis of OS at 3, 5 and 10 years revealed statistically significant differences between complete and incomplete resections: R0 vs R1/R2 (P = 0.032, P = 0.003, P = 0.001, respectively). While there were no statistically significant differences in FFR for the type of surgery: EPP vs TP vs LP, there were differences in OS [1-year: P = 0.010], DFS [3-year: P = 0.021 and 5-year: P = 0.037] and CSS [1-year: P = 0.012 and 3-year: P = 0.041]. The calculation of OS, DFS, CSS and FFR for thymomas versus TCs at 1, 3, 5 and 10 years revealed statistical significance for all analysis. Analysis of OS and CSS revealed a statistically significant survival advantage for patients with MG (10-year OS: P = 0.010; the 5 and 10-year CSS: P = 0.047 and P = 0.014, respectively; Fig. 4 and Supplementary Material, Table S6). In non-EPP patients with pericardial resection (n = 52), there was significantly worse survival at 10 years (OS at 1, 3, 5 and 10 years for pericardial resection yes (n = 52) vs no (n = 52): 98.0% vs 100.0% (P = 0.322), 93.3% vs 100.0% (P = 0.082), 86.7% vs 97.0% (P = 0.082), and 55.1% vs 87.2% (P = 0.010), respectively.
Figure 4  Survival analysis: comparison of primary pleural surgery and pleural surgery for recurrence: OS (A), FFR (B), type of surgery: EPP vs TP vs LP: OS (C), FFR (D), thymoma vs TC: OS (E), FFR (F), and completeness of resection: OS (G), FFR (H). EPP: extrapleural pneumonectomy; TP: total pleurectomy; LP: local pleurectomy; TC: thymic carcinoma.