Prognostic Impact of Deletion 17p Clone Size on Outcome in Chronic Lymphocytic Leukemia Patients (A Real Life Routine Practice Perspective in Brazil)

Abstract Objectives: Chronic lymphocytic leukemia (CLL) presents a heterogeneous clinical course. Treatment mainly aims to control clinical manifestations and improving survival. Some biological markers have significant prognostic value. Cytogenetic studies in CLL have central role to refine the follow-up of disease evolution, to guide treatment options and monitoring response. Due to low mitotic index in conventional cytogenetic studies, fluorescence in situ hybridization (FISH) became an indispensable tool. The main objective of this study was analyze the presence of del(17p13) using FISH and the percentage of positive cells that have impact on survival, along with clinical characteristics from CLL patients. Methods: Seventy-one CLL patients were studied from 2010 to 2017. Median age was 57 years old and male patients were 56,4%. FISH analysis was performed using peripheral blood samples from patients and TP53 spectrum srange/CEP 17 spectrum green probe (Vysis). Statistical analysis was performed with SPSS20.0 software. Results: Twenty-eight of 71 patients had positive FISH for del(17p13) and the evidence of more than 20% del(17p13) cells was related to a worse overall survival (p<0,05). No difference in survival was observed between negative FISH patients and those with less than 20% del(17p13) cells. Conclusions: Patients presenting del(17p13) in more than 20% of cells had worse prognosis with reduced survival. Our results suggest the prognostic relevance of deletion17p clone size detected by FISH in CLL patients. Disclosures Bigni: Janssen: Honoraria, Research Funding.