Antigenic differences were demonstrated between the primary murine
fibrosarcoma and its
metastases. Immunization with irradiated primary
tumor cells (TC) protected C57B1/6J mice against subsequent challenge with those cells, but not against challenge with cells from pulmonary
metastases (PMC). Mice immunized with irradiated PMC were protected from challenge with those cells, but not against challenge with TC. Mice with
fibrosarcomas produced by the injection of 5 X 10(3) cells from the primary
tumor were treated by resection of the
tumor-bearing limb (
Amp),
Amp plus
cyclophosphamide (
Amp + Cy),
Amp plus primary TC (
Amp + TC),
Amp plus primary TC and from its metastatic variant (
Amp + TC + PMC), and with combinations of the last two groups with Cy. Although
Amp + Cy improved survival, no animal lived 100 days and
metastases increased as compared to controls.
Immunotherapy significantly improved survival and decreased pulmonary
metastases.
Antigen combinations from primary and metastatic
tumors resulted in significantly better survival than did a single preparation only from TC.
Chemotherapy did not enhance the results obtained with
immunotherapy and surgery. Immunity conferred in long-term survivors was permanent.