Systematic review of high dose chemotherapy and autologous haematopoietic stem cell transplantation for chronic lymphocytic leukaemia: what is the published evidence?

Summary Despite improved responses, chronic lymphocytic leukaemia (CLL) remains incurable with conventional chemotherapy. Patients with poor‐risk factors or who fail conventional chemoimmunotherapy are offered autografts, preferably after achieving remission. This report presents the totality of evidence through a systematic review that assessed the efficacy of autografts in CLL. A search of MEDLINE databases from 1966–2006 and hand‐search of references identified 82 prospective‐randomized, non‐randomized comparisons or single‐arm trials, of which only nine met our inclusion criteria: two trials were funded by public/government, one by private foundations, one jointly by private/public, and was unclear in five. No randomized controlled trials comparing autografts versus conventional chemotherapy (or chemoimmunotherapy) were found. Six studies were single‐arm and three were non‐randomized with a control‐arm (autologous versus allogeneic). Overall, 361 patients were enrolled, but only 292 were transplanted. Transplant‐related mortality ranged from 0% to 9%. Complete responses ranged from 74% to 100% and molecular responses ranged from 57% to 88%. Overall survival ranged from 68% at 3 years to 58% at 6 years. It is uncertain whether autograft is superior to conventional therapy. The high incidence of myelodysplastic syndrome (9–12%) is particularly concerning in CLL, where median survival is 9 years.