PROGNOSTIC IMPACT OF IMMUNOHISTOCHEMICAL P53 EXPRESSION IN BONE MARROW BIOPSY IN HIGHER RISK MDS: A PILOT STUDY

Background and objectives: Mutations of the TP53 gene have an unfavorable prognosis in Myelodysplastic Syndromes (MDS). The product of the TP53gene is the p53 protein. Most of TP53mutations entail the accumulation of the protein in the nucleus of tumor cells. The immunohistochemical (IHC) staining for p53 can be a surrogate suggesting a mutational status and, if overexpressed, seems to be of prognostic value by itself. The best prognostic cut-off value of overexpression is controversial. The aim of this pilot study is to investigate about the correct value from a homogenous group of patients with higher IPSS-R risk MDS. Methods: In sixty consecutive patients diagnosed with MDS and categorized as IPSS-R risk “intermediate”, “high” and “very high”, the bone marrow biopsies performed at the diagnosis were retrospectively re-examined for IHC p53 expression. The result of p53 expression was subsequently related to survival. Results: A worst overall survival was observed both in patients whose IHC p53 expression was ≥5% and ≥ 10% compared to the patients with a p53 expression respectively below 5% (p= 0.0063) or 10% (p=0.0038). Conclusions: The ICH p53 expression in bone marrow biopsy in higher risk MDS was confirmed to have prognostic value. These results indicate more than 10% expression as the best cut off value.