FULL DOSE VINCRISTINE (WITHOUT 2-MG DOSE LIMIT) IN THE TREATMENT DF LYMPHOMAS

Background. Most current lymphoma protocols limit vincristine dose to 2 mg per single dose. Because a lower dose of vincristine maybe associ ated with poorer outcome, there is some rationale to increase the dose of vincristine. Methods. The feasibility of full dose vincristine (i. e., 1.4 mg/m(2) without 2-mg dose limit) was prospectively evaluated i n lymphoma patients treated with various combinations. After an initia l dose of 1.4 mg/m(2), patients were carefully monitored; and dose was modified according to toxicity. Results. One hundred and four consecu tive patients (31 with Hodgkin's disease and 73 with non-Hodgkin's lym phoma), aged 18-78 years were evaluated. The first dose was greater th an 2 mg in 90% of the patients. The mean actual dose (percent of proje cted dose) was 100% in the first course and gradually decreased to 84% in the eighth course. The mean actual dose intensity of vincristine ( percent of projected dose;intensity) during the initial six cycles of prednisone, methotrexate, calcium leucovorin, doxorubicin, cyclophosph amide, etoposide, and mechlorethamine, vincristine, procarbazine predn isone (ProMACE/MOPP), cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP), and MQPP/doxorubicin, bleomycin, and vinblastine (M OPP/ABV) was 82% and MOPP/doxorubicin, bleomycin, and vinblastine was 82%, 83%, and 87%, respectively. Symptoms of neuropathy developed in 9 2% of the patients and were usually of mild or moderate severity. Toxi city included World Health Organization (WHO) Grades 3 and 4 constipat ion in 10 (10%), and WHO Grade 3 peripheral neurotoxicity in 16 (23%) patients. Rapid improvement was usually noticed within a few weeks aft er withdrawal of vincristine. The median duration of symptoms from dis continuation of vincristine was 3 months for paresthesiae and motor we akness and 5 months for muscle cramps. Conclusions. Full dose vincrist ine in lymphoma protocols is feasible but is associated with increased toxicity. The therapeutic advantage of full dose vincristine has yet to be proven.