The impact of visceral pleural invasion on survival in patients with ipsilateral lymph node involvement in non-small cell lung cancer

Objective: Lung cancer is the leading cause of cancer-related deaths worldwide. Its incidence is increasing in Turkey, particularly among women. The most significant prognostic factors in lung cancer are the disease stage and histological cell type. Tumor size, lymph node involvement, and distant organ metastasis determine the disease stage. Pleural involvement also alters the stage independently of tumor size. This study aims to investigate the effects of visceral pleural invasion on survival in patients with ipsilateral lymph node involvement (N2) after pathological examination following lung resection for non-small cell lung cancer. For this purpose, patients with ipsilateral lymph node positive status were compared in terms of pleural involvement presence or absence, and the results were discussed in line with the literature. Materials and Methods: The files of 1581 patients operated on for primary lung cancer between September 2011 and July 2020 at Cukurova University Balcali Hospital, Department of Thoracic Surgery, were retrospectively reviewed. After applying exclusion criteria, the study group consisted of 1400 patients. Among the screened patients, 233 had ipsilateral lymph node involvement, and visceral pleural involvement was detected positively in twenty-five of these patients. The follow-up period was determined as 12-72 months. Data on patients' age, gender, tumor side, surgical procedures performed, histological type of the tumor, tumor size, and staging based on visceral and parietal pleural involvement at the time of diagnosis were retrospectively examined digitally and from archive files. Statistical analyses were conducted using the SPSS system. Results: Among the examined patients, 233 were evaluated as having ipsilateral lymph node (N2) positivity. Of these N2-positive patients, 186 (79.8%) were male, and 47 (20.2%) were female. Thirty-five (15%) of N2-positive patients had visceral pleural invasion. The median survival time in N2-positive patients without visceral pleural invasion was 23.37 months (95% confidence interval: 7.27-29.47), while in the group with visceral pleural invasion, it was 19.83 months (95% confidence interval: 9.71-29.96). No statistically significant difference was observed between the two groups. Conclusion: The involvement of N2 lymph nodes is considered a crucial factor sharply deteriorating prognosis. Although visceral pleural invasion independently indicates a poor prognosis, its impact does not stand out in N2-positive patients, where N2 disease appears to be more influential than other factors. We believe that visceral pleural invasion does not affect survival durations in the presence of N2 disease.