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288 Point mutations in myelodysplastic syndromes: Associations with clinical features and independent predictors of overall survival
Posters / Leukemia Research 35 (2011) S27–S142
287 Validation of a flow cytometric scoring system for the prognostication of the myelodysplastic syndromes; A retrospective cohort study C. Alhan, T.M. Westers, C. Cali, G.J. Ossenkoppele, A.A. van de Loosdrecht. Hematology, VU University Medical Center, Amsterdam, The Netherlands The International Prognostic Scoring System (IPSS) and WHObased prognostic scoring system provide prognostic information in myelodysplastic syndromes (MDS). However, even if patients are allocated in the same risk category their clinical course remains heterogeneous. Previous studies demonstrated that flow cytometry (FC) and specifically a flow cytometric scoring system (FCSS) is emerging as a valuable technique for predicting outcome in MDS. The FCSS is a scoring system that allows for a numerical display of immunophenotypic aberrancies in the (im)mature myelo-monocytic lineage (Wells, Blood 2003). Scores are generated by enumerating abnormalities; high scores reflect high number of aberrancies. The current study aimed to validate the FCSS for identification of prognostic subgroups in MDS. We analyzed aberrancies in (im)mature myelo-monocytic cells by FC in BM of 107 MDS patients, including 48 MDS patients from a previous cohort. The diagnoses according to WHO 2001 classification were RA(RS) n = 20, RCMD(RS) n = 60, RAEB-1 n = 14, RAEB-2 n = 13 and age-matched healthy volunteers (n = 39) were included. The FCSS in RA(RS) (median = 3, range 1–6) patients was significantly higher compared with healthy controls (median = 1, range 0–2, p < 0.001). In contrast to our previous results the FCSS for RA(RS) and RCMD(RS) patients did not differ. This is a remarkable finding, since by morphology RA(RS) patients show only unilineage dysplasia, in contrast to flow cytometric findings, where 85% of the RA(RS) patients had two or more aberrancies in the (im)mature myelomonocytic compartment. Patients with a high FCSS experienced a significantly worse overall survival (OS) compared with patients with an intermediate FCSS (p = 0.001, median OS 28 and 89 months, respectively). Remarkably, the FCSS was not correlated with IPSS cytogenetic risk categories low, intermediate and poor. However, within the good risk category according to IPSS, the FCSS identified different prognostic subgroups. Patients with good cytogenetics and a high FCSS have a worse OS compared to those with intermediate FCSS (p = 0.001, median OS 39 and 164 months, respectively). Transfusion data was available in 77 patients. Interestingly, the majority of MDS patients who were transfusion dependent or progressed into AML, had aberrant expression of CD5, CD7 and/or CD56 on myeloid progenitors compared with patients without aberrant marker expression (50% vs 24%, respectively; p = 0.012). In conclusion, the FCSS and detection of aberrant myeloid progenitors can provide refined prognostication within currently used classification and prognostication systems. The FCSS can identify patients at risk for transfusion dependency and adverse clinical outcome, independent of current classification systems. 288 Point mutations in myelodysplastic syndromes: Associations with clinical features and independent predictors of overall survival R. Bejar1,2 , K. Stevenson3 , O. Abdel-Wahab4,5 , N. Galili6 , B. Nilsson1 , G. Garcia-Manero7 , H. Kantarjian7 , A. Raza6 , R.L. Levine4,5 , D. Neuberg3 , B. Ebert1,2 . 1 Hematology, Department of Medicine, Brigham and Women’s Hospital, 2 Medical Oncology, Dana Farber Cancer Institute, 3 Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, MA, 4 Human Oncology and Pathogenesis Program, 5 Leukemia Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, 6 Hematology – New York Presbetyrian Hospital, Columbia University, New York, NY, 7 Department of Leukemia, MD Anderson Cancer Center, Houston, TX, USA Myelodysplastic syndromes (MDS) are clonal disorders with variable clinical features for which therapy is highly risk adapted. Prognostic
S113
scoring systems stratify patients into risk groups based on clinical measures, bone marrow blast percentage, and cytogenetic abnormalities, but point mutations are not considered. In order to understand the frequency, overlap, and clinical impact of point mutations in MDS, we examined a cohort of 439 patient samples for mutations in cancers genes. First we screened 191 samples for the presence of 953 known oncogenic mutations in over 111 cancerrelated genes using mass spectroscopic genotyping (OncoMap). Mutations were identified in 10 genes. Known oncogenic mutations in these genes were then sought in an expanded cohort of 439 MDS patient samples. Somatic mutations in additional samples were found for 6 of these genes: NRAS, KRAS, BRAF, JAK2, PTPN11, and GNAS. Our second approach utilized next-generation 454pyrosequencing or Sanger sequencing of 13 other genes known to be mutated in MDS. In aggregate, somatic mutations in 18 genes were identified with 51% of samples carrying at least one mutation, including 52% with normal cytogenetics. The most frequently mutated genes were TET2 (21%), ASXL1 (14%), RUNX1 (9%), TP53 (8%), and EZH2 (6%). TP53 mutations were largely exclusive of other mutations were highly associated with complex cytogenetics and abnormalities of chromosome 17. TET2 mutations were not predictive of survival, even after stratification by International Prognostic Scoring System (IPSS) risk group and mutant allele burden. Mutations of RUNX1, NRAS, and TP53 were associated with lower platelet counts (p < 0.001 each). Mutations in these genes and CBL were associated with higher bone marrow blast proportions (p≤0.01 each). In a multivariable model including age, sex, IPSS risk group, and the mutational status of 13 genes, mutations of TP53 (hazard ratio [HR], 2.48; 95% confidence interval [CI], 1.60– 3.84), EZH2 (HR, 2.13; CI, 1.36–3.33), ETV6 (HR, 2.04; CI, 1.08–3.86), RUNX1 (HR, 1.47; CI, 1.01–2.15), and ASXL1 (HR, 1.38; CI, 1.00– 1.89) were independent predictors of decreased overall survival. Mutations in any of these prognostic genes were present in 31.2% of samples. In summary, we identified point mutations in 18 genes in a cohort of 439 patient samples with more than 50% harboring at least one mutation. Mutations in several genes were associated with clinical features of MDS. Mutations in any of 5 genes were independent predictors of decreased survival, demonstrating that point mutations add information to risk stratification systems used in clinical practice. 289 Prognostic evaluation of chronic myelomonocytic leukemia (CMML) with different prognostic models M. Breccia, P. Finsinger, R. Latagliata, L. Cannella, G. Loglisci, V. Federico, M. Santopietro, G. Colafigli, A. Serrao, A. Salaroli, L. Petrucci, G. Alimena. Dept Hematology, Sapienza University, Roma, Italy Currently, CMML is considered a subtype of MDS/MPN disease, classified outside the whole spectrum of MDS. Despite this, CMML patients have treatment options similar to those of MDS patients. However, prognosis is considered to be worse and several attempts have been made to evaluated outcome. Aim of our study was to detect baseline prognostic features associated to overall survival and risk of leukemic transformation. From July 1983 to November 2009, 117 patients were diagnosed as having CMML in our Institution: median age 71 years, 79 males and 38 females. FAB criteria identified 66 patients as having CMML-1 (median age 68.4 years, 48 males and 18 females) and 51 patients as CMML-2 (median age 66, 31 males and 20 females). Stratification into two categories identified higher transfusional requirement (60.7% vs 31.8%, p = 0.001) and higher risk of acute transformation (39% vs 11%, p = 0.01) in CMML-2 subset. According to WHO classification, 80 patients were reclassified as CMML-1 and 37 patients as CMML-2: the latter category showed shorter overall survival (OS) (1.5 years vs 2.4 of CMML-1 subset) and higher risk of transformation (35% vs 10% of CMML-1 subset). We also attempted to subdivide our patients according to MDACCs’
287 Validation of a flow cytometric scoring system for the prognostication of the myelodysplastic syndromes; A retrospective cohort study C. Alhan, T.M. Westers, C. Cali, G.J. Ossenkoppele, A.A. van de Loosdrecht. Hematology, VU University Medical Center, Amsterdam, The Netherlands The International Prognostic Scoring System (IPSS) and WHObased prognostic scoring system provide prognostic information in myelodysplastic syndromes (MDS). However, even if patients are allocated in the same risk category their clinical course remains heterogeneous. Previous studies demonstrated that flow cytometry (FC) and specifically a flow cytometric scoring system (FCSS) is emerging as a valuable technique for predicting outcome in MDS. The FCSS is a scoring system that allows for a numerical display of immunophenotypic aberrancies in the (im)mature myelo-monocytic lineage (Wells, Blood 2003). Scores are generated by enumerating abnormalities; high scores reflect high number of aberrancies. The current study aimed to validate the FCSS for identification of prognostic subgroups in MDS. We analyzed aberrancies in (im)mature myelo-monocytic cells by FC in BM of 107 MDS patients, including 48 MDS patients from a previous cohort. The diagnoses according to WHO 2001 classification were RA(RS) n = 20, RCMD(RS) n = 60, RAEB-1 n = 14, RAEB-2 n = 13 and age-matched healthy volunteers (n = 39) were included. The FCSS in RA(RS) (median = 3, range 1–6) patients was significantly higher compared with healthy controls (median = 1, range 0–2, p < 0.001). In contrast to our previous results the FCSS for RA(RS) and RCMD(RS) patients did not differ. This is a remarkable finding, since by morphology RA(RS) patients show only unilineage dysplasia, in contrast to flow cytometric findings, where 85% of the RA(RS) patients had two or more aberrancies in the (im)mature myelomonocytic compartment. Patients with a high FCSS experienced a significantly worse overall survival (OS) compared with patients with an intermediate FCSS (p = 0.001, median OS 28 and 89 months, respectively). Remarkably, the FCSS was not correlated with IPSS cytogenetic risk categories low, intermediate and poor. However, within the good risk category according to IPSS, the FCSS identified different prognostic subgroups. Patients with good cytogenetics and a high FCSS have a worse OS compared to those with intermediate FCSS (p = 0.001, median OS 39 and 164 months, respectively). Transfusion data was available in 77 patients. Interestingly, the majority of MDS patients who were transfusion dependent or progressed into AML, had aberrant expression of CD5, CD7 and/or CD56 on myeloid progenitors compared with patients without aberrant marker expression (50% vs 24%, respectively; p = 0.012). In conclusion, the FCSS and detection of aberrant myeloid progenitors can provide refined prognostication within currently used classification and prognostication systems. The FCSS can identify patients at risk for transfusion dependency and adverse clinical outcome, independent of current classification systems. 288 Point mutations in myelodysplastic syndromes: Associations with clinical features and independent predictors of overall survival R. Bejar1,2 , K. Stevenson3 , O. Abdel-Wahab4,5 , N. Galili6 , B. Nilsson1 , G. Garcia-Manero7 , H. Kantarjian7 , A. Raza6 , R.L. Levine4,5 , D. Neuberg3 , B. Ebert1,2 . 1 Hematology, Department of Medicine, Brigham and Women’s Hospital, 2 Medical Oncology, Dana Farber Cancer Institute, 3 Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, MA, 4 Human Oncology and Pathogenesis Program, 5 Leukemia Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, 6 Hematology – New York Presbetyrian Hospital, Columbia University, New York, NY, 7 Department of Leukemia, MD Anderson Cancer Center, Houston, TX, USA Myelodysplastic syndromes (MDS) are clonal disorders with variable clinical features for which therapy is highly risk adapted. Prognostic
S113
scoring systems stratify patients into risk groups based on clinical measures, bone marrow blast percentage, and cytogenetic abnormalities, but point mutations are not considered. In order to understand the frequency, overlap, and clinical impact of point mutations in MDS, we examined a cohort of 439 patient samples for mutations in cancers genes. First we screened 191 samples for the presence of 953 known oncogenic mutations in over 111 cancerrelated genes using mass spectroscopic genotyping (OncoMap). Mutations were identified in 10 genes. Known oncogenic mutations in these genes were then sought in an expanded cohort of 439 MDS patient samples. Somatic mutations in additional samples were found for 6 of these genes: NRAS, KRAS, BRAF, JAK2, PTPN11, and GNAS. Our second approach utilized next-generation 454pyrosequencing or Sanger sequencing of 13 other genes known to be mutated in MDS. In aggregate, somatic mutations in 18 genes were identified with 51% of samples carrying at least one mutation, including 52% with normal cytogenetics. The most frequently mutated genes were TET2 (21%), ASXL1 (14%), RUNX1 (9%), TP53 (8%), and EZH2 (6%). TP53 mutations were largely exclusive of other mutations were highly associated with complex cytogenetics and abnormalities of chromosome 17. TET2 mutations were not predictive of survival, even after stratification by International Prognostic Scoring System (IPSS) risk group and mutant allele burden. Mutations of RUNX1, NRAS, and TP53 were associated with lower platelet counts (p < 0.001 each). Mutations in these genes and CBL were associated with higher bone marrow blast proportions (p≤0.01 each). In a multivariable model including age, sex, IPSS risk group, and the mutational status of 13 genes, mutations of TP53 (hazard ratio [HR], 2.48; 95% confidence interval [CI], 1.60– 3.84), EZH2 (HR, 2.13; CI, 1.36–3.33), ETV6 (HR, 2.04; CI, 1.08–3.86), RUNX1 (HR, 1.47; CI, 1.01–2.15), and ASXL1 (HR, 1.38; CI, 1.00– 1.89) were independent predictors of decreased overall survival. Mutations in any of these prognostic genes were present in 31.2% of samples. In summary, we identified point mutations in 18 genes in a cohort of 439 patient samples with more than 50% harboring at least one mutation. Mutations in several genes were associated with clinical features of MDS. Mutations in any of 5 genes were independent predictors of decreased survival, demonstrating that point mutations add information to risk stratification systems used in clinical practice. 289 Prognostic evaluation of chronic myelomonocytic leukemia (CMML) with different prognostic models M. Breccia, P. Finsinger, R. Latagliata, L. Cannella, G. Loglisci, V. Federico, M. Santopietro, G. Colafigli, A. Serrao, A. Salaroli, L. Petrucci, G. Alimena. Dept Hematology, Sapienza University, Roma, Italy Currently, CMML is considered a subtype of MDS/MPN disease, classified outside the whole spectrum of MDS. Despite this, CMML patients have treatment options similar to those of MDS patients. However, prognosis is considered to be worse and several attempts have been made to evaluated outcome. Aim of our study was to detect baseline prognostic features associated to overall survival and risk of leukemic transformation. From July 1983 to November 2009, 117 patients were diagnosed as having CMML in our Institution: median age 71 years, 79 males and 38 females. FAB criteria identified 66 patients as having CMML-1 (median age 68.4 years, 48 males and 18 females) and 51 patients as CMML-2 (median age 66, 31 males and 20 females). Stratification into two categories identified higher transfusional requirement (60.7% vs 31.8%, p = 0.001) and higher risk of acute transformation (39% vs 11%, p = 0.01) in CMML-2 subset. According to WHO classification, 80 patients were reclassified as CMML-1 and 37 patients as CMML-2: the latter category showed shorter overall survival (OS) (1.5 years vs 2.4 of CMML-1 subset) and higher risk of transformation (35% vs 10% of CMML-1 subset). We also attempted to subdivide our patients according to MDACCs’