Comparison of Clinical Characteristics and Prognostic Factors between Gastric Lymphoepithelioma-like Carcinoma and Gastric Adenocarcinoma

Abstract

Gastric lymphoepithelioma-like carcinoma (LLC) is a rare cancer that presents with a unique histologic pattern that is characterized by poorly differentiated malignant cells infiltrating the background stroma along with massive lymphocyte infiltration. Many studies have shown that gastric LLC is associated with better prognosis than other gastric malignancies. However, the reason for better prognosis has not been clarified and the underlying mechanism remains to be elucidated. Therefore, we attempted to determine the clinical characteristics of gastric LLC and identify its prognostic factors related to improved survival. A total of 18 patients were diagnosed with gastric LLC after resection from 2005 to 2012 at Department of Gastroenterology in Chungnam National University Hospital. The data of these patients were compared with 36 age- and sex-match-ed patients with poorly differentiated gastric adenocarcinoma who also underwent resection during the same study period. Postoperative recurrence or metastasis tended to occur less frequent in gastric LLC than in poorly-differentiated gastric adenocarcinoma. Among prognostic factors, only the number of lymph node metastases showed significant difference, with gastric LLC being associated with a smaller number of lymph node metastases. Regarding the disease free and overall survival rate, both were higher for gastric LLC than for poorly-differentiated gastric adenocarcinoma, albeit not statistically significant (p=0.089 and p=0.159, respectively). Poorly differentiated gastric adenocarcinoma was associated with a higher number of lymph node metastases at diagnosis than gastric LCC. Other potential factors affecting prognosis were not significantly different between the two cancer types.