- CHEMO, HORMONAL, AND RADIOTHERAPY There is a limit of two prior chemotherapy regimens which patients may have received; (patients who have received extensive prior cytotoxic therapy may no longer have adequate organ function and may not be eligible); at least 4 weeks must have elapsed from the end of previous chemotherapy, hormonal therapy, or radiotherapy (six weeks for nitrosoureas or mitomycin); concurrent chemotherapy, hormonal therapy or radiotherapy is not permitted; patients on steroids, including replacement therapy, will be excluded from the study