Is the aberrant expression of p53 by immunocytochemistry a surrogate marker of TP53 mutation and/or deletion in chronic lymphocytic leukemia?

摘要

We read with interest the article by Chang et al in which the aberrant expression of nuclear p53 detected by immunohistochemical analysis in 10% or more of bone marrow biopsy cells of 14 of 110 patients affected by chronic lymphocytic leukemia (CLL) identified all but 1 case with del(17p) in 10% or more of cells by fluorescent in situ hybridization (FISH). Deletion of chromosome 17p13 occurs in 5% to 7% of untreated CLLs and in 20% to 30% of relapsed or resistant cases and is strongly associated with TP53 mutations of the remaining allele; however, in 3% to 4.5% of cases, the TP53 mutation is not associated with the deletion, but it still maintains its adverse prognostic value. TP53 mutations lead to an accumulation of an abnormal prolonged half-life p53 protein, which can be detected by immunohistochemical or immunocytochemical analysis.