Proportion of Adult AML Patient Population Receiving Allogeneic Stem Cell Transplantation and Long-Term Outcome: Real World Data From the Swedish National Acute Leukemia Registry.

Abstract 2289

Poster Board II-266

Allogeneic transplantation is established post-remission therapy in CR1 for AML patients with high risk features, but not in low-risk disease. However, most have intermediate risk, where indications for SCT are less clear. Most SCT outcome data derive from transplant cohorts, and data on patients studied from diagnosis are scarce. Real world population-based data on the effects of transplant is lacking. We have evaluated the role of transplant for AML in the updated Swedish National Acute Leukemia Registry (Blood 2009;113:4179), which covers 98% of all adult patients nationwide diagnosed 1997-2006 and followed up to 2009, i.e., a median observation on survivors of >6 years. Sweden has a population of 9 million people with full access to high-quality therapy for AML including SCT. Registry data were validated from regional transplant center databases. Of 3878 patients with acute leukemia, 3312 had AML (1669 males and 1643 females), and 457 had ALL; 109 had undifferentiated/unclassified AL. AlloSCT in AML non-APL was performed in 8% of patients aged 60-64 years at diagnosis, and 2% of those aged 65-69 years. We then focused on adult AML non-APL patients <60 years (n=782) of which 38% had alloSCT (n=294), similar in both sexes. Two thirds of the alloSCTs were performed in CR1 (64% for males and 72% for females), 22% in CR2 or later CR, and 10% not in CR. Donors were matched unrelated in 48% of transplants in CR1 and ‘not in CR', and 60% in CR2. Of patients having AlloSCT in CR1, 62% are currently alive, as compared to 50% for CR2 patients, and 31% of others. Corresponding figures for sib and unrelated donors were 65% and 56% in CR1, 50% and 53% in CR2, and 40% and 22% if not in CR.

Transplant-reported mortality (TRM), i.e. death in CR after SCT was reported in 13% (with another 6% without reported cause of death). Interestingly, these figures were similar for SCT performed in CR1, CR2 and ‘not in CR'. TRM in CR1 was 10(-12)% with sib donor and 16(-19)% with MUD; in CR2 12(-33)% and 17(-25)%; and if not in CR 13(-20)% and 14(-21)%, respectively; ranges include those with no reported cause of death.

Swedish healthcare is divided into six geographical regions, all with full therapeutic options and minimal referral in between regions. We are therefore able to study the influence on outcome in relation to the proportion of transplanted AML patients. One region (#3) performed alloSCT in 63% of AML non-APL patients <60 years, another (#2) in 23%, and the remaining four regions in between 33% and 41%. The corresponding proportions for alloSCT in CR1 were 45% (#3), 16% (#2), and 23 through 28% (others). The main reason for this difference was that alloSCT was frequently performed also in ages 40-59 years in region #3. The 8-year total survival of the overall AML non-APL population <60 years (i.e. including those with no SCT) was 52% in region #3, and ranged from 32% through 39% in the other five regions. This real world report on the use of SCT for AML points at existing regional differences in management, and suggests a possible relation to long-term outcome.