Second and third responses to the same induction regimen in relapsing patients with multiple myeloma.

From September 1975 to December 1986,115 consecutive previously untreated patients with multiple myeloma (MM) were treated with combination chemotherapy consisting of BCNU, cyclophosphamide, melphalan, vincristine, and prednisone (M-2). No patients were excluded or lost during follow-up. Forty-three percent of the patients were Stage I plus 11, and 57% were Stage 111. Thirty-eight patients (33%) had blood urea nitrogen greater than or equal to 40 mg/dl (substage B). Reaching an objective response treatment was stopped, generally after 1 year, and restarted at relapse. After induction therapy, 94 patients (82%) responded and had a median duration of response (MDR) of 22 months. After first relapse, 26 of 38 patients (69%) responded again to the same regimen and had an MDR of 11 months. This response rate and MDR are significantly lower than the ones achieved in induction chemotherapy. After second relapse, 7 of 16 patients (44%) again responded with an MDR of 3.5 months. The median survival time (MST) was 50.5 months for all patients. The most relevant side effect was leukopenia. No case of secondary leukemia was noticed. The authors conclude that patients with MM can be treated safely without maintenance therapy after reaching remission because a high response rate can be obtained in first and even second relapse. The planned treatment pause at remission does not adversely affect the survival time. Secondary leukemia is infrequent after this policy. Quality of life improves during the treatment pause. Cancer 68:975-980,1991.