Prognostic significance of the NPM-ALK fusion gene in bone marrow and peripheral blood for patients with anaplastic large cell lymphoma

Abstract

To investigate the expression of NPM- ALK fusion gene in bone marrow (BM) and peripheral blood (PB) in anaplastic large cell lymphoma (ALCL) patients and its prognostic significance. NPM- ALK fusion gene of 21 BM and 15 PB samples from patients with NPM-ALK positive ALCL was detected by RT- PCR, and the relationship between NPM- ALK expression and prognosis and clinical characters was evaluated. Of the 21 patients, 12 cases were male and 9 case were female with a median age of 9 (range, 2-14) years old. The median follow- up was 31 months. Patients with a positive NPM-ALK expression in BM had a 3-years EFS of (35.6±18.6)%, compared with (91.7±8.0)% for patients with negative NPM-ALK (P=0.038). The incidence of positive expression in BM was significantly higher in patients who had more than 3 organs involved by tumor (P=0.032). 86.7% patients had a concordant results of NPM-ALK expression in PB and BM. We could evaluate the minimal disseminated disease of NPM-ALK positive ALCL patients by screening the NPM-ALK fusion gene in BM and PB by RT-PCR. The positive expression is associated with a poor prognosis and could be used for stratification of ALCL.