Results of treatment of lymphoblastic lymphoma at the children cancer hospital Egypt – A single center experience

Abstract

IntroductionLymphoblastic lymphoma (LBL) and acute lymphoblastic leukemia (ALL) are neoplasms of immature B or T-cell precursors. They are considered as a unique biological entity in the 2008 World Health Organization Classification of Hematologic Neoplasm. Both entities are arbitrarily separated by a cut-off point of 20–25% of blast cells in the bone marrow. Treatment of LBL has evolved over time from conventional high-grade NHL schedules to ALL-derived protocols.The aim of this work is to report the clinical characteristics, overall survival (OS), event free survival (EFS), and common chemotherapy toxicities of lymphoblastic lymphoma (LBL) patients during a 5.5year period.Patients and methodsA Retrospective review of patient’s charts diagnosed and treated as LBL during the period between July 2007 and end of December 2012 was done. Patients were treated according to St. Jude Children Research Hospital ALL Total Therapy XV protocol, standard risk arm.ResultsThis study included 77 patients. T-cell LBL patients were 67, while 10 were of B-cell origin. The median age at diagnosis was 9years (95% CI: 7–10). The majority were males 54/77. Stage III patients were 51, stage IV 13, stage II 11 and stage I 2 patients. Two patients were excluded from analysis as they died before receiving chemotherapy. Complete remission post induction chemotherapy was seen in 22 patients considered early responders, and partial remission in 55 considered late responders. With a median follow up duration of 47months (95% CI: 38–56), the 4year overall survival and event free survival were 86.45% (95% CI: 73.78–94.09) and 82.18% (95% CI: 69.25–90.61) respectively.Twelve patients died during the study period; 2 early deaths before starting chemotherapy from disease progression, 2 in CR due to chemotherapy related toxicity and 8 from disease progression. All the relapsed patients were T-cell, had advanced disease at presentation (6 with stage III; 2 with stage IV). Two patients (2.6%) had isolated local, BM, and CNS relapse each, while 1 (1.3%) had both local and CNS relapse. Disease recurrence was local in 3 patients (3.9%), and systemic in 5 (6.4%), while it was early in 6 (7.8%), and late in 2 (2.6%) patients. Median time to disease progression was 20months (range 5–39months). All relapsed patients did not survive salvage chemotherapy. The most common chemotherapy toxicities were cerebral venous thrombosis (20%), followed by bone infarcts (10.6%), and avascular necrosis (AVN) of head of femur (9.3%). One patient developed secondary acute myeloid leukemia after 3years of FU with unfavorable cytogenetic abnormalities.ConclusionResults of treatment of LBL on the St Jude’s total therapy XV study are comparable to most of the similar reported studies. Outcome of relapsing patients is extremely poor, hence there is a need to identify biologic or clinical prognostic factors including minimal residual tumor to better evaluate chemotherapy response. Steroid induced AVN, and cerebral vascular thrombosis were the main chemotherapeutic adverse events.