ACUTE T-LYMPHOBLASTIC LEUKEMIA/LYMPHOBLASTIC T-CELL LYMPHOMA. ROLE OF EARLY allo-SCT

Precursor T cell LBL/ALL is a rare and aggressive neoplastic disorder. Clinical features are bulky mediastinal disease, pleural effusion and bone marrow involvement by blasts oriented versus T-lineage, also with acute leukemia clinical presentation. It’s matter of debate the role and the correct timing of allogeneic stem cell transplantation (allo-SCT). We report clinical outcome results of 8 newly diagnosed and younger than 60 years T-ALL patients (median age 33 years, range 23-47 years, 5 males, 3 females), from Jan 2010 to Dec 2014, treated in induction with HyperCVAD and alternated Metotrexate/ARA-C schedule. All patients had bulky mediastinal at diagnosis. Six of eight patients had bone marrow involvement at diagnosis. Five of them had TCR positivity in PCR on bone marrow blood, (3 of them had a bi-clonal peak). Patients were treated with a range from one to four HyperC-VAD/MTX-ARA-C course, on the base of the obtainment of the best response. Two patient presented refractory disease in course of induction, and shifted to a second line therapy; three patients obtained a partial response and 3 obtained a complete response after induction. Responsive patients with HLA-matched donor underwent allo-SCT with conventional conditioning regimen (TBI-Cy). Two patients underwent allo-SCT in first remission (one in CR, by haploidentical donor; one in PR, by sibling). Two patients underwent allo-SCT after a second line therapy, made necessary by a loss of response during the period required to search and mobilization of the donor (one by haploidentical donor, one by MUD, both in PR). At the end of follow-up, the two patients treated with allo-SCT in first remission were alive and in CR. The two patients who underwent allo-SCT in second remission both died by sepsis in aplasia after alloSCT. All other patients died for progression of disease after second line therapy. Survival analyses on Overall survival (OS), according to the Kaplan-Meier method, showed a median OS of 18,65 months. Median 5-years OS was 26%. None of clinical features investigated showed significant association with OS. Consistent with the low number of cases, we could note a trend in favour of allo-SCT in first remission (Figure 1) (p 0.059) and TCR negativity on BM (Figure 2) (p 0.11). In conclusion, efforts should be directed towards a the development of new drugs (eg, nelarabine), and the strengthening of clinical trials that help to understand the correct timing for allo-SCT.