AbstractSoluble tumor-associated antigens were isolated from Lewis lung carcinoma (3LL) cells by detergent solubilization and purified by affinity chromatography on peanut agglutinin (PNA)-agarose. Subcutaneous injection of PNA-binding glyco-related antigen into 3LL-bearing male C57BL/6 mice significantly augmented delayed-type hypersensitivity (DTH), and also inhibited the growth of the primary 3LL tumors. The effects of combined immunotherapy and chemotherapy with this antigen and cyclophosphamide (CY) were examined following excision of 3LL by determining the number of pulmonary surface nodules and wet weight of the lungs. Injection of PNA-binding glyco-related antigen and CY significantly inhibited pulmonary metastasis and prolonged the survival of the mice. The spleen cells obtained from mice with combined treatment showed higher neutralizing activity against 3LL cells than other groups. Therefore, combined immuno and chemotherapy may be useful in preventing metastasis.