At Three Years, Patients With Acute Lymphoblastic Leukaemia Are Still At Risk For Relapse. Results Of The International Mrc Ukallxii/Ecog E2993 Trial

Late relapse [>3 years from complete remission (CR)] in acute lymphoblastic leukaemia (ALL), is unusual. Data from the MRC UKALLXII/ECOG E2993 trial are presented to evaluate the incidence and characteristics of late relapse in adult ALL. Of 1,909 patients, 1,752 (92%) achieved CR and among these 757 (43 center dot 2%) relapsed; 691 (91 center dot 3%) within three years and 66 (8 center dot 7%) beyond. Among these 66 patients, median time to relapse was 47 (37-144) months. Relapse beyond three years occurred in 3 center dot 8% of all who achieved CR. The cumulative risk of relapse was 40%, 43% and 45% at three, five and ten years respectively. Out of the 1 752 patients who achieved CR, 11 center dot 7% underwent autologous and 40 center dot 6% allogeneic transplant, while in CR1. Of the autologous patients, 43 center dot 2% relapsed early and 3 center dot 4% relapsed late. However, among the allogeneic patients, 13 center dot 2% relapsed early and only 1 center dot 3% late. The five-year overall survival from relapse was 5 center dot 8% and 20% in the early and late relapse patients respectively. In conclusion, late relapse in adults with ALL is not uncommon, and is associated with better outcome after relapse compared to early relapse.