Superior 12-Year Survival After at Least 4-Year Continuous Remission with Tandem Transplantations for Multiple Myeloma

BackgroundComplete response has been considered a surrogate for favorable long-term outcome in multiple myeloma. Data on the impact of the duration of response on prognosis are lacking.Patients and MethodsOf the 899 patients enrolled in Total Therapy trials (Total Therapy 1, N = 231; Total Therapy 2, N = 668), 254 survived for > 5 years. The prognostic impact of continuous (Rc) versus discontinuous (Rd) 4-year remission after 5-year survival was examined along with laboratory features present at baseline and at 5 years.ResultsMost baseline prognostic features were evenly distributed among Rc and Rd groups; however, a greater proportion of Rc patients were enrolled in Total Therapy 2 (60%) compared with Rd (19%; P < 0.001). Twelve-year survival (7 years after the 5-year landmark) was 66% with Rc and only 30% with Rd. Hypodiploidy and deletion 13, present in 24 patients at baseline, were associated with a 12-year survival of only 20%. Among the 200 patients lacking these cytogenetic abnormalities, Rc (n = 141) defined a superior 12-year survival rate of 70% versus 35% among those with Rd (n = 59). Initial quality of response (complete response) or having received the scheduled tandem transplantations did not affect post-5-year survival.ConclusionFive-year Rc appears to be an important prerequisite for prolonged subsequent overall survival.