Background: High-dose chemotherapy with autologous stem cell support (HDT) has been proven effective in relapsed aggressive non-Hodgkin lymphoma (NHL). However, conflicting results of HDT as part of first-line treatment have been reported in randomised controlled trials (RCTs). We undertook a systematic review and meta-analysis to assess the effects of such treatment.
Objectives: To determine whether high-dose chemotherapy with autologous stem cell transplantation as part of first-line treatment improves survival in patients with aggressive non-Hodgkin lymphoma.
Search strategy: MEDLINE, EMBASE, Cancer Lit, the Cochrane Library and smaller databases, Internet-databases of ongoing trials, conference proceedings of the American Society of Clinical Oncology and the American Society of Hematology were searched. We included full-text, abstract publications and unpublished data.
Selection criteria: Randomised controlled trials comparing conventional chemotherapy versus high-dose chemotherapy in the first-line treatment of adults with aggressive non-Hodgkin lymphoma were included in this review.
Data collection and analysis: Eligibility and quality assessment, data extraction and analysis were done in duplicate. All authors were contacted to obtain missing data and asked to provide individual patient data.
Main results: Fifteen RCTs including 3079 patients were eligible for this meta-analysis. Overall treatment-related mortality was 6.0% in the HDT group and not significantly different compared to conventional chemotherapy (OR 1.33 [95% CI 0.91 to 1.93], P=0.14). 13 studies including 2018 patients showed significantly higher CR rates in the group receiving HDT (OR 1.32, [95% CI 1.09 to 1.59], P=0.004). However, HDT did not have an effect on OS, when compared to conventional chemotherapy. The pooled HR was 1.04 ([95% CI 0.91 to 1.18], P=0.58). There was no statistical heterogeneity among the trials. Sensitivity analyses underlined the robustness of these results. Subgroup analysis of prognostic groups according to IPI did not show any survival difference between HDT and controls in 12 trials (low and low-intermediate risk IPI: HR 1.41[95% CI 0.95 to 2.10], P=0.09; high-intermediate and high risk IPI: HR 0.97 [95% CI 0.83 to 1.13], P=0.71. Event-free survival (EFS) also showed no significant difference between HDT and CT (HR 0.93, [95% CI 0.81 to 1.07], P=0.31). Other possible risk factors such as the proportion of patient with diffuse large cell lymphoma, protocol adherence, HDT strategy, response status before HDT, conditioning regimens and methodological issues were analysed in sensitivity analyses. However, there was no evidence for an association between these factors and the results of our analyses.
Authors' conclusions: . Despite higher CR rates, there is no benefit for high-dose chemotherapy with stem cell transplantation as a first line treatment in patients with aggressive NHL.