A STUDY OF NATURAL KILLER CELLS IN REGIONAL LYMPH NODE OF COLON CANCER PATIENTS

Abstract

The role of natural killer (NK) cells in regional lymph nodes was immunohistochemically investigated in patients with colon cancer. NK cells were detected with monoclonal antibody Leu7. Five hundred and thirty lymph nodes were isolated from 62 colon cancers with lymph node metastasis and were examined. Number of Leu7 positive cells in lymph nodes was compared with various factors including liver metastasis, peritoneal dissemination, depth of tumors, staging, pathological diagnosis, with or without metastasis in each lymph node and prognosis.The following results were obtained.1. Number of NK cells in metastatic lymph nodes was significantly decreased. Especialy, cases with the number of less than 1000/cm2 had poor prognosis.2. Number of NK cells in metastatic lymph nodes from mucinous adenocarcinoma was significantly decreased compared with other histologic carcinoma.3. Number of NK cells in non-metastatic lymph nodes was significantly correlated with the staging and lymph node involvement.It was suggested that the advance of a cancer caused the oppression of immune response at regional lymph nodes as self-defence mechanism, which might contribute to a further advance of the cancer.