BACKGROUND: En-bloc resection for cancer has been a standard procedure based on the concept that there may be a small number of "invisible" cancer cells around the primary tumor and metastatic lymph nodes. However, there are few histopathologic studies of this issue. METHODS: Perinodal involvement of cancer cells, defined as existence of cancer cells in the attached fatty tissue around the dissected lymph nodes, was assessed in 123 node-positive and 15 node-negative gastric cancers by both hematoxylin-eosin staining and immunohistochemistry. RESULTS: Perinodal involvement was found in 79 (57%) of the 138 patients. The incidence was higher in patients with tumors invading the deeper layer, the macroscopic diffuse type, the presence of lymphatic or vascular invasion (P<.05), and advanced disease (stage I, 17%; II, 62%; III, 67%; IV, 80%). Survival of patients with perinodal involvement was less than that of patients without perinodal involvement (46% vs 87%; P<.005). Perinodal involvement was found, by multivariate analyses, to be a significant prognostic factor. CONCLUSIONS: Perinodal cancer cells are observed frequently in gastric cancers with lymph node metastases, and the involvement appears to be a reliable prognostic factor for gastric cancers.
BACKGROUND: En-bloc resection for cancer has been a standard procedure based on the concept that there may be a small number of "invisible" cancer cells around the primary tumor and metastatic lymph nodes. However, there are few histopathologic studies of this issue. METHODS: Perinodal involvement of cancer cells, defined as existence of cancer cells in the attached fatty tissue around the dissected lymph nodes, was assessed in 123 node-positive and 15 node-negative gastric cancers by both hematoxylin-eosin staining and immunohistochemistry. RESULTS: Perinodal involvement was found in 79 (57%) of the 138 patients. The incidence was higher in patients with tumors invading the deeper layer, the macroscopic diffuse type, the presence of lymphatic or vascular invasion (P<.05), and advanced disease (stage I, 17%; II, 62%; III, 67%; IV, 80%). Survival of patients with perinodal involvement was less than that of patients without perinodal involvement (46% vs 87%; P<.005). Perinodal involvement was found, by multivariate analyses, to be a significant prognostic factor. CONCLUSIONS: Perinodal cancer cells are observed frequently in gastric cancers with lymph node metastases, and the involvement appears to be a reliable prognostic factor for gastric cancers.
Authors: Cristina Graham Martínez; Nikki Knijn; Marcel Verheij; Iris D Nagtegaal; Rachel S van der Post Journal: Histopathology Date: 2019-02-10 Impact factor: 5.087