- Prior chemotherapy: Before entry to this protocol, patients must have derived maximal benefit from conventional, i.e., nonmyeloablative, doses of combination chemotherapy. Conventional therapy should be continued until either a complete remission is achieved, no further benefit from non-myeloablative dosing can be appreciated, or toxicity from conventional therapy is perceived as limiting in the absence of stem cell rescue. The cancer must be proven to be sensitive to alkylating agents. This means that, in addition to, or as part of, the appropriate chemotherapy protocol for the specific cancer in question, all patients must have received and responded to a minimum of: