Regression of established oral tumors after intralesional injection of living BCG or BCG cell walls.

Oral tumors with associated cervical lymph node metastases developed after injection of tumor cells into buccal pads of inbred guinea pigs. Intralesional injection of living BCG or BCG cell walls (CW) caused regression of established tumors, prevented the development of cervical lymph node metastases and led to the development of host resistance to the growth of subsequent tumor transplant.