Risk assessment in adult acute lymphoblastic leukaemia before early haemopoietic stem cell transplantation with a geno-identical donor: an easy clinical prognostic score to identify patients who benefit most from allogeneic haemopoietic stem cell transplantation.

In 1402 patients allografted in Europe during the period 1990-2000 with an HLA-identical sibling in first remission (CR1), the median interval from CR1 to allotransplant (96 days) was a major prognostic factor, patients transplanted earlier having a worse outcome. We studied in depth the 414 fully evaluable patients transplanted less than 96 days after achieving CR1; in these patients, only three factors predicted for the outcome by multivariate analysis: patient age, CR1 achievement with one or more induction courses and the recipient/donor sex combination. These three factors overcame the information from cytogenetics and source of stem cells. Three prognostic groups could be identified in relation to the outcome, using a prognostic score affecting 1 to each poor risk factor (total from 0 to 3): Group 1 (good prognosis) includes patients <35 years old, achieving CR1 with one induction course and to be transplanted with any other sex combination than female to male (score 0); group 2 (intermediate) with one adverse factor (score 1); and group 3 (bad prognosis) with two or three adverse criteria (scores 2 and 3). In these three groups, the 3-year leukaemia-free survival was 56+/-5%, 48+/-4% and 29+/-4% and the overall survival was 65+/-5, 53+/-4 and 29+/-5%, respectively. Therefore, adult patients with ALL and a score of 0 or 1 are good candidates for an early transplant if they have an identical sibling donor. Patient age, response to induction and the sex of the HLA-identical family donor (if existing) are the strongest easy predictors of the outcome for an early transplant in an adult patient with ALL. No additional information is mandatory.