[The role of an immunologic mechanism in the occurrence of postoperative metastases in mice].

A comparative analysis of metastatic spread into lungs after tumor removal in immunologically normal mice (group 1) and those with splenectomy, thymectomy and congenital athymia-induced immunity disorders (group 2) was conducted. The largest number of lung metastases was found after tumor removal in group 1, the smallest in nude mice (group 2). The use of any method of lowering T-lymphocyte level (splenectomy, thymectomy or a single administration of low-dose cyclophosphamide) was shown to result in a significantly smaller number of lung metastases after tumor removal. It is suggested that formation of metastases after tumor removal is caused by an immunological factor which is possibly associated with an active response of T-suppressors.