Abstract: | Seventy-six patients with squamous cell carcinoma of the esophagus (SCE) were treated with either cisplatin and mitomycin in combination or as single agents on ECOG protocol 2278. Sixty-six patients were evaluated for toxicity. Of 13 evaluable mitomycin and cisplatin treated patients, six (46%) experienced ECOG grade 4 thrombocytopenia and/or leukopenia. Of 28 evaluable patients treated with mitomycin alone, two (7%) experienced such toxicity; and of 25 evaluable patients treated with cisplatin alone, none experienced this toxicity. The average total dose prior to toxicity for those receiving mitomycin and cisplatin in combination was 51 mg and 131 mg, respectively, with average time to toxicity 3.6 weeks. For those two patients who received mitomycin alone, the average total dose was 68 mg and average time to toxicity 6.5 weeks. For those patients receiving cisplatin alone, the average total dose was 220 mg. The reasons for the enhanced hematologic toxicity of the agents together are not apparent, but it would be prudent to caution investigators using these agents in combination with potentially myelosuppressive drugs. |