Prognosis and distribution of lymph nodes metastases in resectable primary pulmonary lymphoepithelioma‐like carcinoma: A large cohort from a single center

BACKGROUND: Primary pulmonary lymphoepithelioma‐like carcinoma is a rare subtype of lung cancer. Until now, the characteristics of lymph nodes metastases in resectable cases have not yet been reported. METHODS: In this study, a total of 87 consecutive patients with primary pulmonary lymphoepithelioma‐like carcinoma that received surgical treatment were investigated from October 1999 to August 2016. The clinical and radiological data and follow‐up information were extracted from hospital records in detail. RESULTS: In a univariate analysis, those patients with an early pathological stage (I–II), low rate of lymph node metastases (<30%) and a low number of positive lymph nodes (<5) showed longer recurrence‐free survival and overall survival (all P < 0.05). However, the early pathological stage was identified as the only factor independently associated with recurrence‐free survival by multivariate analysis (P = 0.038). In a preoperative lymph nodes evaluation, the accuracy and specificity of computed tomography alone were 52.9% (46/87) and 88% (302/343), respectively, and 73.2% of these cases with incorrect nodal staging (30/41) were upstaged. Skipping metastases were more frequent in operated stage N2 cases (71.4%), whereas whether or not those patients showed skipping metastasis did not affect their recurrence‐free survival or overall survival (P > 0.05). The highest metastasis frequencies for specific lobes with primary lymphoepithelioma‐like carcinoma are as follows: #5 left upper lobe (21.4%); #7 left lower lobe (40.7%); #2R (28.6%) and/or #4R (14.3%) right upper lobe; #7 (42.9%) right lower lobe; #7 (28%) and/or superior mediastinal nodes (36%) right middle lobe. CONCLUSION: Based on accurate staging and uncertain survival benefit, complete mediastinal lymph nodes dissection is still required for curative resection.