[Immunomorphology of lymph nodes and prognosis in lung cancer]

Many studies have investigated locoregional immune responses and long-term survival in various types of cancer; few have focused on lung cancer. This study was designed to assess the prognostic value of immunomorphologic changes in locoregional lymph nodes in patients resected for bronchogenic carcinoma.

In a retrospective analysis, immune responses in locoregional lymph nodes were studied histologically in 172 selected patients. Lymph node morphology was studied according to the system of Cottier et al.: sinus histiocytosis (SH) and paracortical lymphoid cell hyperplasia (PCA) were considered as a cellular immune response, and follicular hyperplasia of the cortical area (CA) as a humoral reaction. The survival rate was estimated by the Kaplan-Meier product-limit method. Log-rank test and Cox proportional-hazards model were used to determine statistical significance in univariate and multivariate survival analysis.

35.5% of the patients had no evident response in regional nodes; 19.8% had a marked cellular response; 11% a marked humoral response; and 33.7% a mixed cellular-humoral response. A nodal cellular response improved long-term survival rates even in patients with regional node metastases. Multivariate analysis identified an independent variable as having high prognostic value: lymph node immunoreactivity.

Lymph node immunoreactivity significantly influences long-term survival after curative surgery for lung cancer and may be useful in stratifying patients for prospective trials of adjuvant treatment including immunotherapy.