Clinical and molecular characteristics and treatment patterns of adolescent and young adult patients with chronic lymphocytic leukaemia.

Chronic lymphocytic leukaemia (CLL) rarely presents in adolescent and young adult (AYA) patients (patients aged 15-39 years). Disease characteristics and outcomes of AYA patients with CLL are not well understood, particularly in the era of novel oral targeted therapies. We analysed outcomes of 227 AYA patients with CLL diagnosed in the last two decades and evaluated at our institution. Median time to first treatment (TTFT) was 2·2 years, and five- and 10-year overall survival (OS) were 90% and 78%, respectively. Pre-treatment elevated beta 2-microglobulin, advanced Rai stage, del(11q) or del(17p) by FISH, unmutated IGHV and CD38 positivity were associated with both shorter TTFT and OS. Within the subgroup of patients who received oral targeted therapy at any time, del(11q) or del(17p) and complex karyotype were associated with shorter OS. First-line treatment choice was significantly associated with time to second treatment (P < 0·001). Patients harbouring del(11q) or del(17p) experienced shorter time to Richter transformation and were more likely to undergo an allogeneic stem cell transplant. There was a significant association between age and both OS and time to Richter transformation. Our study is the first analysis of AYA patients with CLL with a large number of patients treated with oral targeted therapies.