The combination of mitomycin-C and etopzoside showed synergistic cell kill effects in vitro against HEp-2 laryngeal squatnous carcinoma cells both in monolayer and in multicellular tumor spheroid systems. This cornbination was also synergistic in inhibiting HEp-2 tumors growing in nude mice. One course of this combination produced no complete regression of this tumor. When these two agents were combined with recombinant human granulocyte colony-stimulating factor (G-CSF) mutein, the doses of the drugs could be escalated approximately 1.5-fold higher than the doses that were tolerated without G-CSF support. With this modest close intensication, apparent cure MWS observed. High-dose mitomycin-C plus etoposide with G-CSF support may be useful, for the treatment of patients with inoperable squamous cell carcinoma of the head and neck.