Comparison of the efficacy of radiotherapy between postoperative mediastinal lymph node recurrence and stage III disease in non-small cell lung cancer patients.

Purpose: It is unknown if local treatment is equally effective in non-small cell lung cancer (NSCLC) patients with postoperative mediastinal lymph node recurrence or primary stage III disease. The purpose of this study was to investigate the effectiveness of radiotherapy, with or without chemotherapy, in patients with postoperative mediastinal lymph node recurrence.

Methods: Patient characteristics, treatment response and survival were compared between NSCLC patients with mediastinal lymph node metastases treated between 2002-2009 by radiotherapy alone or by chemoradiotherapy (group A, N=33) and those with primary stage III disease (group B, N = 157).

Results: Men accounted for 60.6% of group A and 78.9% of group B (p=0.04 patients). ECOG performance status 0 was detected in 78.7% of group A and 57.3% of group B (p=0.02). The response rates in groups A and B were 66.6 and 72.3%, respectively (p=0.64). Progression-free survival (PFS) was similar between groups A and B (median 15.0 vs 11.0 months; hazard ratio [HR] 0.78; 95% CI 0.51-1.20; p=0.26). However, overall survival (OS) was better in group A than in group B (median 67.0 vs 39.0 months; HR 0.56; 95% CI 0.29-0.97; p=0.03). Postoperative PFS (median 12.5 vs 19.0 months; HR 1.50; 95% CI 0.64-3.49; p=0.34) and OS (median, 67.0 vs 60.0 months; HR 1.22; 95% CI 0.36-4.14; p=0.74) were similar between the group A treatments (radiotherapy and chemoradiotherapy, respectively).

Conclusion: Postoperative mediastinal lymph node recurrent NSCLC demonstrated distinctive features including better OS compared to patients with primary stage III disease, despite similar response rates and PFS.