EFFECTS OF CHEMOIMMUNOTHERAPY WITH AND WITHOUT SURGERY IN MURINE MBT-2 BLADDER-TUMOR

Using C3H/He JCr mice bearing the syngeneic MBT-2 bladder tumor, it wa s found that cyclophosphamide (CYC 100 mg/kg i.p.) treatment, 1 day be fore and 2 weeks after surgery, followed by postoperative autologous t umor vaccine immunization can be an effective adjuvant anticancer ther apy. The shortterm exogeneous addition of low dose II-2 administration to the protocol provided no further benefit. Suppression of tumor gro wth was observed in a classical Winn assay when splenocytes were obtai ned on day 23 from mice receiving this effective adjuvant therapy with surgery on day 8. Splenocytes from tumor-bearing mice (TBM) treated w ith CYC were augmented in terms of their proliferative response to con canavalin A during the first 2 weeks after CYC treatment. Studies usin g 3-day TBM established that significant suppression of tumor growth a nd prolonged survivals were dependent upon CYC treatment being combine d with tumor vaccine and/or interIeukin-2; single agent treatments wer e ineffective.