Clinical Significance of ALK-1 Gene Abnormalities in Diffuse Large Cell Lymphoma

OBJECTIVES: To detect relative frequency of anaplastic lymphoma kinase (ALK-1) gene abnormality in diffuse large cell lymphoma (DLCL) using fluorescence in situ hybridization (FISH), and correlate its presence with clinicopathological features which may be useful for choice of therapy and predict survival in newly diagnosed cases. PATIENTS AND METHODS: A prospective study was done between March 2004 and October 2009. Fifty patients newly diagnosed with DLCL were enrolled into the study. Immunophenotyping was done and detection of ALK-1 gene abnormalities were carried out by immunohistochemically (IHC) and FISH. Patients that proved to be ALK-1 positive were treated with standard cyclophosphamide –hydroxy-daunorubicin- oncovin-prednisone (CHOP) protocol. RESULTS: All ALK +ve patients achieved complete remission (CR) vs. 93.5% CR and 6.5% partial remission (PR) for ALK −ve patients respectively. Disease free survival (DFS) at 24 months was 81.8% in the CHOP-14 group (ALK-1(−)) vs. 100% for the CHOP-21 group (ALK-1(+)). Overall survival (OS) at 30 months was 80.4% in the CHOP-14 group vs. 100% for the CHOP-21 group.