Impact on survival of high-dose therapy with autologous stem cell support in patients younger than 60 years with newly diagnosed multiple myeloma: a population-based study

High-dose therapy has become a common treatment for myeloma. The objectives of this study were to estimate in a prospective, population-based setting the impact on survival of high-dose therapy in newly diagnosed, symptomatic patients less than 60 years old and to compare the results with those of c onventionally treated historic controls. The prospective population compris ed 348 patients. Of these, 274 were treated according to a specified intens ive-therapy protocol (Nordic Myeloma Study Group [NMSG] #5/94) and constitu ted the intensive-therapy group. The historic population consisted of 313 p atients identified from 5 previous population-based Nordic studies. Of thes e, 274 fulfilled the eligibility criteria for high-dose therapy stated in N MSG #5/94 and constituted the control group. The expected numbers of patien ts in the prospective population and the historic population were 450 and 4 10, respectively, estimated from previously established data on the inciden ce in this population and the population base for each study. Survival was prolonged in the intensive-therapy group compared with the control group (r isk ratio for the control group 1.62; 95% confidence interval 1.22-2.15; P = .001). These groups represented more than 60% of the expected number of p atients, When survival for all the registered patients in the 2 populations was compared, representing more than 75% of the expected number of patient s, the advantage for the prospective population persisted (risk ratio for t he historic population 1.46; 95% confidence interval 1.14-1.86; P = .002), These results indicate that the introduction of high-dose therapy for newly diagnosed myeloma has resulted in prolonged survival for the total patient population aged less than 60 years. (C) 2000 by The American Society of He matology.