OBJECTIVES: I. Determine whether a single mitomycin C treatment will suppress expression of one or more proteins associated with the multidrug resistance phenotype in leukemia cells of patients with refractory acute myelogenous leukemia. II. Determine the maximum tolerated dose of a combination of mitomycin C followed 72 hours later by a single dose of mitoxantrone in patients with acute myelogenous leukemia with GM-CSF support. III. Determine the toxicity profile and pharmokinetics for these combinations of mitomycin C and mitoxantrone. IV. Determine the ability of this regimen to induce complete response in patients with primary resistant or refractory acute myelogenous leukemia.