Immunotherapeutic effect of tumor necrosis after cryosurgery, electrocoagulation, and ligation

Tumor necrosis in situ by cryosurgery, electrocoagulation, or ligation generally induces or augments some increase in tumor-specific transplantation immunity (TSTI) as compared with excision. Excision of the tumor 24 hours after it has been rendered ischemic by either ligation or cryosurgery seems to produce TSTI that is significantly greater than that after excision of viable tumor without prior ligation or cryosurgery; the degree of this immunity is similar to that seen after the tumor is left in situ indefinitely after treatment. These data suggest that most of the immunization following tumor necrosis in situ occurs within 24 hours of treatment. The experimental findings support the clinical reports of putative immunologic potentiation after tumor necrosis in situ.