Destruction of regional lymph node metastases of rat mammary adenocarcinoma 13762A by treatment with Corynebacterium parvum.

Intratumoral administration of Corynebacterium parvum to 13762A tumor-bearing rats on Day 7 of tumor growth, followed by primary tumor excision on Day 20, regularly cured about 40% of the animals and significantly prolonged survival in the remainder. Rats treated by surgery alone on either Day 7 or Day 20 died with metastases to axillary lymph nodes and lungs. Tumor was established in axillary lymph nodes by Day 7. Therefore, intratumoral injection of C. parvum on Day 7 destroyed metastases already established at this site. Growth of tumor in axillary nodes of rats treated but not cured by C. parvum was significantly slower than growth in untreated rats.