[A collaborative study of children with lymphoblastic non-Hodgkin's lymphoma in China].

OBJECTIVE: To evaluate the feasibility of conducting a collaborative study and efficacy of lymphoblastic non-Hodgkin's lymphoma (LBL) treatment protocols in children with LBL in China retrospectively and to explore the clinical and prognostic features as well as treatment response of LBL, in order to better regulate the treatment for further improving the prognosis.

METHOD: Seven tertiary referral centers for childhood cancer actively participated in this study. Shanghai Children's Medical Center (SCMC) 2007, SCMC-2011 and NHL-2010 protocols of treatment were modified based on BFM-90/95 regimen originated from Germany. SCMC-2007 and SCMC-2011 were used in Shanghai Children's Medical Center and NHL-2010 was used in other centers. Uniform data collection forms were sent out to all the centers and collected back via e-mail. The clinical data were then analyzed with primary focus on clinical presentations, and laboratory findings. Kaplan-Meier method was used to compare the survival rates between groups, while multiple factors logistic regression was used to identify the prognostic/relapse factors.

RESULT: (1) A total of 96 patients were recruited. The median age at diagnosis was 8.6 (1.1-16.2) years. The male-to-female ratio was 3.2:1. (2) The immunophenotype was T-cell LBL in 77 patients (80%) and precursor B-cell LBL in 19 patients (20%), respectively. According to St. Jude staging classification, 6 patients (6%) were divided into stage I, 6 patients (6%) into stage II, 51 patients (53%) into stage III, 32 patients (33%) into stage IV and 1 patient with isolated bone involvement. (3) With a median follow up of 21 months (0.3-60.7 months), the 2-year overall survival (OS) rates and event-free survival (EFS) rates were (89±3)% and (68±5)%, respectively, and the 5-year probability of OS and EFS were (88±4)% and (64±6)%, respectively in all patients. Out of all, 23 patients received SCMC-2007 protocol, 15 patients received SCMC-2011 protocol and 58 patients received NHL-2010 protocol. The 2-year OS and EFS were (91±6)% and (70±10)% in SCMC-2007 study, 100% and (92±8)% in SCMC-2011 study, (83±6)% and (72±6)% in NHL-2010 study, respectively. For patients with complete response on day 33, the 2-year EFS was (77±6)% compared with (17±10)% for patients with incomplete response (P<0.005). (4) In 13 patients (20%) the disease relapsed. The median relapse time range was 8 months (1-31 months). Six patients suffered from progressive disease. Logistic regression analysis showed that incomplete response on days 33 was an independent unfavorable prognostic factor (OR=4.138, P=0.035).

CONCLUSION: Despite the apparent existence of gap between China and International states in the diagnostic and treatment approaches towards childhood LBL in China, with implementation of further modification of treatment protocols to strengthen cooperation between domestic tertiary centers, the long-term survival rate and reduction of recurrence of childhood LBL in China can be markedly improved.