Clinical significance of p53 mutations in nonhodgkin's lymphoma

At an attempt to evaluate if tumor suppressor gene max play a role in leukemogenesis, we surveyed 84 non-Hodgkin's lymphoma (NHLs) Among them histologically. 72 cases were intermediate grade (IMG) and 12 were high grade (HG) according to Working Formulation; and immunogenetically 55 cases were of B origin and 29 were T The p53 gene alterations were studied by Southern blot technique and single strain conformation polymorphism (SSCP) analysis DNA rearrangement \\as detected in 3 cases and point mutation in 6 However, no case was found to have both kinds of gene alterations All the gene alterations were found exclusively in the B-cell NHLs. One of the 3 cases with p53 gene rearrangement and 3 of the 6 cases with point mutation sho\\ ed immunohistochemically p53 protein expression The pathological subclassfication of the NHLs with p53 gene rearrangement revealed diffuse large cell type in two patients and diffuse mixed cell type in one On the other hand, of the 6 NHLs with point mutations. 4 were found to be diffuse large cell type, diffuse mixed cell t\pe in another and diffused small cleaved cell type in the rest one All the patients with p53 gene rearrangement and 3 of 6 patients with p53 mutations achieved complete remission (CR) after chemotherapy but relapsed eventually C-myc oncogene was also surveyed in this study. Only three patients showed gene rearrangement The results indicated that incidence of the p53 mutations and c-myc gene rearrangement was less common in this series in comparing to that in the Western countries. The clinical features showed a poor survival in spite of a high CR rate This indicates that p53 mutations in NHL predict a poor prognosis.