Long-term outcomes of surgery in resectable single-station N2 non-small cell lung cancer patients

Abstract

Background: This study aims to examine the factors influencing prognosis and long-term survival outcomes in pathological single-station N2 (pN2a) patients undergoing surgical treatment for non-small cell lung cancer.

Methods: Between January 2012 and June 2021, a total of 144 patients (125 males, 19 females; mean age: 60.5±8.4 years; range, 48 to 78 years) who underwent anatomical resection for non-small cell lung cancer and were identified with pN2a disease were retrospectively analyzed. Factors influencing prognosis were analyzed. Survival analysis was performed.

Results: Forty-nine (34%) patients received neoadjuvant therapy and 87 (60.4%) patients underwent lobectomy. In terms of staging, 95 (66%) patients were classified as Stage 3A, while 49 (34%) patients were categorized as Stage 3B. Analysis of N2 subtypes revealed that 77 (53.5%) patients were classified as known N2, whereas 67 (46.5%) patients were identified as incidental. Histopathological evaluation revealed that 58 (40.3%) patients had adenocarcinoma, while 86 (59.7%) patients had non-adenocarcinoma histology. N2 disease was categorized as skip metastasis (pN0N2a) in 61 (42.4%) patients and non-skip metastasis (pN1N2a) in 83 (57.6%) patients. Adjuvant therapy was administered to 126 (87.5%) patients, with treatment modalities determined by the oncology clinics and patient characteristics. Among these, 46 (31.9%) patients received chemotherapy, 15 (10.4%) patients underwent radiotherapy, and 65 (45.1%) patients were treated with chemoradiotherapy. The five-year overall survival rate was 33.9% with a median duration of 37.1±5.0 months. The disease-free survival rate was 24.9% with a median duration of 18.2±2.3 months. Adenocarcinoma histology, non-skip N2 disease, lack of adjuvant therapy, and advanced age (>65 years) were found to be significant factors affecting the prognosis of pN2a disease.

Conclusion: The findings of this study indicate that adenocarcinoma histology, advanced age, absence of adjuvant therapy, and the presence of pN1N2a are significant prognostic factors in pN2a patients undergoing curative resection for non-small cell lung cancer.

Keywords: Adenocarcinoma; adjuvant therapy; elderly; lymph node; non-small cell lung cancer; single station N2; skip N2; surgery..

Figure 1. (a) Overall survival assessment (Kaplan-Meier analysis). (b) Skip N2 - non-skip N2 survival (Kaplan-Meier analysis). (c) Survival by neoadjuvant treatment and non-neoadjuvant treatment. (d) Histological subtypes (Kaplan-Meier analysis)

Figure 2. Disease free survival. (a) Overall survival assessment (Kaplan-Meier analysis). (b) Skip N2-non-Skip N2 Survival (Kaplan-Meier analysis). (c) Survival by neoadjuvant treatment and non-neoadjuvant treatment. (d) Histological subtypes (Kaplan-Meier analysis).