Impact of immunoglobulin heavy chain variable region mutational status on the outcome of patients with chronic lymphocytic leukemia harboring isolated 13q deletion.

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6608 Background: Several prognostic factors can predict the course of chronic lymphocytic leukemia (CLL). Among them, the IGVH mutational status and the presence of cytogenetic abnormalities are the strongest predictors of outcome. Mutated IGVH and deletion 13q independently confer a survival advantage. CLL patients with mutated IGVH in combination with deletion 13q have a better prognosis when compared to their unmutated IGVH counterparts. However, there is limited data on the outcome of patients harboring favorable deletion 13q and the unfavorable unmutated IGVH. This study aimed at identifying patients with these two indicators in order to obtain important prognostic information. Methods: We used the Moffitt Cancer Center Total Cancer Care (TCC) database to find patients with a diagnosis of CLL between January 1993 and December 2009. Individual charts were reviewed for demographic data and CLL cytogenetics, including IGVH mutation status and presence of deletion 13q. We analyzed the impact of having deletion 13q in combination with an unmutated IGVH on the overall survival (OS) for this subset of CLL patients using Kaplan Meier curves with SPSS statistical software. Results: 546 patients were identified during the aforementioned time period with a diagnosis of CLL. Median age was 62.5 years. 144 (26.4%) of these patients had IGVH and cytogenetic analysis available. 53 patients had 13q deletion as their sole genetic abnormality. Patients with unmutated IGVH and positive for deletion 13q were 19/53 (35.8%). Patients with mutated IGVH and positive for deletion 13q were 34/53 (64.2%). Patients with mutated IGVH and positive for deletion 13q had an OS of 17 years. While patients with unmutated IGVH and positive deletion 13q had a lower median OS of 12 years (91.2% vs 78.9%, p=0.05). Hazard ratio for patients with IGVH mutated and positive deletion 13q was 0.4, p=0.05. Conclusions: Mutated IGVH appears to be associated with improved OS in patients with isolated 13q deletion when compared to patients with unmutated IGVH and isolated 13q deletion. Further research is needed to assess these mutations in relation to other cytogenetic abnormalities in CLL.