Prospective, randomized study of single compared with double autologous stem-cell transplantation for multiple myeloma: Bologna 96 clinical study. Cumulative meta-analysis of therapeutic trials for myocardial infarction.
We performed a prospective, randomized study of single (arm A) versus double (arm B) autologous stem-cell transplantation (ASCT) for younger patients with newly diagnosed multiple myeloma (MM).
                A total of 321 patients were enrolled onto the study and were randomly assigned to receive either a single course of high-dose melphalan at 200 mg/m2 (arm A) or melphalan at 200 mg/m2 followed, after 3 to 6 months, by melphalan at 120 mg/m2 and busulfan at 12 mg/kilogram (arm B).
                As compared with assignment to the single-transplantation group (n = 163 patients), random assignment to receive double ASCT (n = 158 patients) significantly increased the probability to attain at least a near complete response (nCR; 33% v 47%, respectively; P = .008), prolonged relapse-free survival (RFS) duration of 18 months (median, 24 v 42 months, respectively; P < .001), and significantly extended event-free survival (EFS; median, 23 v 35 months, respectively; P = .001). Administration of a second transplantation and of novel agents for treating sequential relapses in up to 50% of patients randomly assigned to receive a single ASCT likely contributed to prolong the survival duration of the whole group, whose 7-year rate (46%) was similar to that of the double-transplantation group (43%; P = .90). Transplantation-related mortality was 3% in arm A and 4% in arm B (P = .70).
                In comparison with a single ASCT as up-front therapy for newly diagnosed MM, double ASCT effected superior CR or nCR rate, RFS, and EFS, but failed to significantly prolong overall survival. Benefits offered by double ASCT were particularly evident among patients who failed at least nCR after one autotransplantation. The large volume of published randomized, controlled trials has led to a need for meta-analyses to track therapeutic advances. Performing a new meta-analysis whenever the results of a new trial of a particular therapy are published permits the study of trends in efficacy and makes it possible to determine when a new treatment appears to be significantly effective or deleterious. We describe the use of such a procedure, cumulative meta-analysis, to assess therapeutic trials among patients with myocardial infarction.
                We performed cumulative meta-analyses of clinical trials that evaluated 15 treatments and preventive measures for acute myocardial infarction.
                An example of this method is its application to the use of intravenous streptokinase as thrombolytic therapy for acute infarction. Thirty-three trials evaluating this therapy were performed between 1959 and 1988. We found that a consistent, statistically significant reduction in total mortality (odds ratios, 0.74; 95 percent confidence interval, 0.59 to 0.92) was achieved in 1973, after only eight trials involving 2432 patients had been completed. The results of the 25 subsequent trials, which enrolled an additional 34,542 patients through 1988, had little or no effect on the odds ratio establishing efficacy, but simply narrowed the 95 percent confidence interval. In particular, two very large trials, the Gruppo Italiano per lo Studio della Streptochinasi nell'Infarto Miocardico trial in 1986 (11,712 patients) and the Second International Study of Infarct Survival trial in 1988 (17,187 patients) did not modify the already established evidence of efficacy. We used a similar approach to study the accumulating evidence of efficacy (or lack of efficacy) of 14 other therapies and preventive measures for myocardial infarction.
                Cumulative meta-analysis of therapeutic trials facilitates the determination of clinical efficacy and harm and may be helpful in tracking trials, planning future trials, and making clinical recommendations for therapy.
We did not consider any study to be sufficiently informative for contemporary treatment decisions concerning the question single versus tandem ASCT in view of inherent biases. In addition, none of the trials integrated the so-called "novel agents" which are now considered standard treatment for MM. To improve the quality of future studies, sample size calculations should consider the potentially steep decrease in compliance with the second ASCT. Reporting of results of treatment- or transplantation-related mortality should clearly specify the type and number of events (the numerator) in a well-defined population (the denominator).