Seventeen consecutive patients with previously untreated poor prognosis Hodgkin's disease (clinical stage II and III with systemic symptoms, and stage IV) received 6 courses of aggressive chemotherapy, with (9 patients) and without (8 patients) the addition of recombinant human granulocyte-macrophage colony stimulating factor (rhGM-CSF). Chemotherapy (MOPP/ABV/CAD regimen) included full doses of nitrogen mustard, lomustine (CCNU), vindesine, melphalan, prednisone, epidoxorubicin, vincristine, procarbazine, vinblastine and bleomycin, and was administered between days 1 and 15 of each course. Course were planned for 28-day intervals. rhGM-CSF was given at a dose of 5 micrograms/kg/day subcutaneously from day 16 to 26 of each course. With cytopenia (i.e. white blood cell, WBC, count < 3.0 x 10(9)/L and/or platelet count < 100 x 10(9)/L) delaying courses was preferred to administering reduced drug dosages. Substantial delays (ranging from 7 to 28 days) in delivering cytostatics were necessary between 70% of courses. The cumulative mean number of days for which the courses had to be delayed before completing the 6 MOPP/ABV/CAD courses was 57. The percentage of planned doses of cytotoxic drugs (nitrogen mustard, melphalan, epidoxorubicin, procarbazine) actually administered was 92%. Causes of treatment delay were presented by leucopenia in 82% and by leuco-thrombocytopenia in 23% of the courses. The WBC nadir was constantly encountered at day 20-21 following completion of courses, and slightly worsened with subsequent courses. The decrease in platelet values was milder than that in WBC counts. There were no differences in any of the above parameters between patients treated with MOPP/ABV/CAD alone or followed by rhGM-CSF.(ABSTRACT TRUNCATED AT 250 WORDS)