ALBERT

Description: Aim: Although 40-65% of myelodysplastic syndromes (MDS) patients are thrombocytopenic and require platelet transfusions, there is limited literature on the risk factors predictive of bleeding and the burden of immune mediated platelet refractoriness (PLT-R). Objectives: To evaluate the prevalence of thrombocytopenia, incidence of bleeding events, platelet transfusion dependency (PLT-TD) and immune-mediated platelet refractoriness (PLT-R) in MDS patients. Methods: A retrospective analysis of 754 MDS patients enrolled in the South Australian MDS (SA-MDS) registry was performed. Platelet counts 50x109/L and 〉100 x109/L in 57 (83%) and 46 (67%) at the time of bleeding events, respectively. During the disease course, 393 (52%) patients required at least one unit of platelet transfusion. 106 (14%) patients were PLT-TD and had significantly poor overall survival (OS) compared to PLT-TI (26 vs 42 months, p50X109/L. For all bleeding events that occurred while on anticoagulation and/or antiplatelet therapy, 83% events occurred with platelet counts 〉50 x 109/L. Therefore, guidelines for anticoagulation and/or antiplatelet therapy are required for MDS patients. We also showed that development of PLT-TD is associated with poor OS. Importantly, 1 in 4 female MDS patients receiving platelets and DMT required HLA-matched platelets. Platelet transfusions practices should be optimised for these high-risk groups. Disclosures No relevant conflicts of interest to declare.

Description: Background: The Revised International Prognostic Scoring System (R-IPSS) stratifies MDS patients better than the original IPSS scoring system. Although RBC-transfusion dependency (RBC-TD) is associated with poor prognosis, it is not included in the R-IPSS. Another limitation of R-IPSS is that it is designed to assess the prognosis of patients only at the time of diagnosis; it does not provide prognostic guidance during the disease course. We hypothesise that the use of RBC-transfusion dependency status as a time-varying covariate improves R-IPSS. Aim: To assess the impact of RBC-TD as a time-varying covariate in addition to R-IPSS in predicting survival outcome of MDS patients. Materials and Methods: To match the patient selection criteria as in R-IPSS, primary MDS patients, AML (blast 20-30%) and CMML (WBC≤12x109/L) not treated with disease modifying agents or stem cell transplantation were included. RBC-TD was defined as RBC transfusion of at least 1 unit/8 weeks for at least 4 months (Malcovati et al; JCO 2007). For the statistical analysis of overall survival (OS) measured in months since diagnosis, the Akaike Information Criterion (AIC) was used to assess the goodness-of-fit of a model. Landmark analyses at 6, 12 and 24 months after the diagnosis were also conducted; individuals who experienced the event (i.e. death) before the landmark time point were excluded. The remaining patients were then classified into two groups – RBC-TD noted at or before the landmark time point and transfusion independent at the landmark time point. Results: In our study, 295 patients met the inclusion criteria for analysis, their median age was 75 years (21-97 years) and 66% patients were male. The majority of patients were RCMD, RAEB1 and RAEB2. R-IPSS improved the risk stratification of MDS patients, predominantly for the IPSS-intermediate group (Table I). The median OS in R-IPSS Very Low, Low, Intermediate, High and Very High risk group was 87, 62, 28, 13 and 12 months respectively (p

Description: Background: Majority of MDS cases appear to be sporadic in nature, but 10-15% have clear familial basis due to predisposing mutations in genes such as RUNX1, GATA2, CEBPA and DDX41. Contribution of germline variants in sporadic MDS is not studied. This study attempts to address the contribution of germline variants in MDS pathogenesis. Methods: We performed amplicon-based massively parallel sequencing (AmpliSeq custom panel adapted for Illumina HiSeq2500 sequencing) on all coding regions of 29 myeloid genes for 144 MDS samples. After identifying the variants in five genes (TET2, MET, GATA2, ASXL1, NOTCH1), we tested an additional 96 MDS samples including therapy-related myeloid neoplasm (T-MN) using a Sequenom assay. We also analyzed WES data for these variants in 178 AML samples and 758 normal controls and AmpliSeq data for ASXL1 and TET2 variants in 655 CML samples. Results: Collation of all coding variants in the 29 myeloid genes sequenced identified germline variants occurring in primary MDS at frequencies significantly higher than expected when compared to the normal population (ExAC and matched cohort were similar) (Table 1). These variants occurred in 5 genes (TET2, MET, GATA2, ASXL1 and NOTCH1) at increased frequencies of 1.5-16.6 fold. Numerous MDS samples had multiple variants (4 with 4 variants, 4 with 3 variants, 18 with 2 variants) while 70 had 1 variant. The 3 germline MET variants have been previously investigated in solid tumorigenesis and likely generate MET variant proteins that contribute to numerous cancer types including MDS. Interestingly, 7/17 (41%) MDS cases with germline MET variants also had other cancers including pancreatic, gastric and laryngeal cancers. Of the TET2 variants, Y867H and P1723S were concurrent in 5 MDS, 5 AML and 6 CML samples indicative of them being on the same allele (i.e. a haplotype). They were seen at higher than normal frequency in MDS and AML, but were not significantly enriched in CML. We are currently confirming their coexistence on the same allele and assaying for decreased TET2 activity to determine whether one or both variants contribute to the phenotype. Other variants identified in MDS include the rare GATA2 (P161A) variant which is present in 1% of the population and the nearby common GATA2 (A164T) allele (~20%). These were mutually exclusive in our cohort and were seen at 3.9 and 1.5-fold, respectively, above the expected population frequency. We generated the P161A variant using site-directed mutagenesis and assayed for GATA2 transactivation activity in HEK293 cells with a GATA2-responsive LYL1 promoter-Luciferase construct (Figure 1). We also included empty vector (EV), wildtype (WT) GATA2 and T354M which is the most common highly penetrant autosomal dominant mutation leading to familial MDS/AML. As expected, T354M displayed a marked decrease in transactivation ability when compared to WT. The P161A variant similarly displayed loss-of-function in this assay, but not to the same magnitude as T354M. This is consistent with the hypothesis that reduced GATA2 function predisposes to myeloid malignancy where decreasing GATA2 activity correlates with increasing risk of developing malignancy. In our study 10/36 (28%) cases harboring these variants were T-MN cases. Apart from MET (E168D) (11.4-fold), the 2 rare variants with highest frequency in MDS versus controls were ASXL1 (N986S) (16.6-fold) and NOTCH1 (R912W) (6.5-fold). ASXL1 is an epigenetic regulator often mutated in hematopoietic malignancy and aberrant NOTCH1 function has been associated with myeloid and lymphoid malignancies. Conclusions: We have identified common and rare germline variants in genes involved in myeloid malignancy that may contribute to MDS pathogenesis. It remains to be seen whether they contribute to initiation, maintenance and/or progression of MDS and other hematopoietic malignancies. This is the first study reporting higher frequency of germline variants in sporadic MDS cases. Table 1. Frequency of germline variants in MDS, AML and CML in comparison to ExAC. Table 1. Frequency of germline variants in MDS, AML and CML in comparison to ExAC. Disclosures Hiwase: Celgene Corporation: Research Funding.

Description: Myelodysplastic syndromes (MDS) are a group of chronic and often progressive myeloid neoplasms associated with remarkable heterogeneity in the degree of cytopenia, morphology and clinical course. Various somatic mutations are involved in the pathogenesis of MDS. The recent identification of acquired mutations in the key components of the spliceosome machinery strongly implicates abnormalities of mRNA splicing in the pathogenesis of myelodysplastic syndromes. In this study, we performed Targeted Massively Parallel Sequencing on a custom 29 myeloid gene panel (all coding regions) of myeloid genes using an AmpliSeq approach (Life Tech) on 148 MDS patient samples. Barcodes were added using NEB kit and libraries were prepared for Illumina HiSeq2500 sequencing. Results: The median age of patients was 72 (19-97) years and 65% patients were male. Majority of patients were RA-RS, RCMD, RCMD-RS, RAEB1 and RAEB2. Conventional bone marrow cytogenetic was normal in 80/148 (55%) of cases while sequencing of 29-gene panel revealed at least one mutation in 131/148 (88%) patients. Importantly a combination of cytogenetic and mutation screening detected genetic abnormalities in 141/148 (95%) of MDS patients, thus highlighting the importance of combining targeted mutation screening along with conventional karyotyping in MDS patients. The majority of patients had more ≥2 mutations 112/148 (75%) suggesting clonal heterogeneity. As shown in Figure (1A), the most frequently mutated genes were ASXL1, SF3B1, NOTCH1, TET2, SRSF2, RUNX1 and DNMT3A. Mutations in the spliceoosome complex genes were detected in 66/148 (44%) of patients with SF3B1 (30/148; 20%) more frequent than SRSF2 (24/148; 16%) and U2AF1 (12/148; 8%). These mutations were mutually exclusive except for one patient. SF3B1 mutations were detected in 95% (19/20) of RA-RS and RCMD-RS cases, while 〉50% of patients with SRSF2 mutations had RAEB1 or RAEB2. Mutations in the spliceosome complex co-occur with mutations in the epigenetic modifiers such as DNMT3A and TET2 mutations which is consistent with the previous report. We identified 47 patients with 2 (n=37) or three (n=10) TET2 mutations. Of these, 16 patients had mutations at significantly different allele frequencies suggesting that independent clones had arisen, raising the possibility that in these samples a pre-leukemic genetic or epigenetic cellular environment exists that selects for TET2 mutations. We also saw a similar trend, although to a lesser extent, for NOTCH1, RUNX1 and NRAS mutations. Conclusions: Combination of targeted sequencing of most commonly mutated genes and conventional cytogenetic can detect genetic abnormalities in 95% of MDS cases. This study shows that 〉75% of MDS cases have more than one mutations demonstrating clonal heterogeneity. SF3B1 mutations are detected in 95% of RA-RS and RCMD-RS cases and are frequently associated with mutations in epigenetic modifiers. A high level of mutation detection has been possible because detection of low level mutations due to deep sequencing. Fig. 1: (A) The most frequently mutated genes were TET2, ASXL1, SF3B1, SRSF2, DNMT3A and RUNX1 (B) Majority of patients had two or more mutations. Fig. 1:. (A) The most frequently mutated genes were TET2, ASXL1, SF3B1, SRSF2, DNMT3A and RUNX1 (B) Majority of patients had two or more mutations. Disclosures No relevant conflicts of interest to declare.

Description: Introduction: Anemia is one of the commonest presenting features of MDS and approximately 30-40% of patients require regular RBC-transfusion. RBC-transfusion dependency (RBC-TD) is a poor-prognostic factor independent of revised International Prognostic Scoring System (IPSS-R) (Hiwase et al ASH 2014). Although RBC transfusion increases the risk of alloimmunization, there is limited literature characterizing this risk in MDS patients as compared to other hematological disorders (such as thalassemia). Methods: This retrospective study assessed the alloimmunization rate in 784 MDS and AML (20-30% blasts) patients registered in the South Australian-MDS registry (SA-MDS registry) between 1991 and 2015. RBC-TD was defined as ≥1 unit of RBC transfused every eight weeks for four months according to WHO based Prognostic Scoring System. The cumulative incidence of RBC-alloimmunization was calculated using competing risk analysis (death being the competing risk). Factors associated with increased rate of RBC antibody formation were investigated by Cox regression analysis. Results: The median age of the 784 patients at diagnosis was 75 years with 66% males. The estimated median follow up time was 7.3 years. 70% of patients (549/784) were diagnosed with primary MDS, while the remaining patients were diagnosed with AML (20-30% blasts; n=57), CMML (n=91) or therapy-related myeloid neoplasm (T-MN; n=87). At last follow-up 30% patients were alive, 67% were deceased and 3% were lost to follow-up. During the study period, 658 (84%) patients required ≥1 unit of RBC transfusion and median RBC units transfused were 29 (range 0-708). The WPSS definition of RBC-TD was met in 47% (366/784 patients), while 36% (282/784) patients required intermittent RBC-transfusions (RBC-TI). During follow up, 83 (13%) patients formed 155 RBC-alloantibodies and 50% of these cases (42/83) developed 〉1 RBC-alloantibody. Autoantibodies were also detected in 31 cases, mainly in association with RBC-alloantibodies (n=27; complex alloimmunization) while 4 cases had only autoantibodies. Interestingly, in 19/27 of cases autoantibodies were detected only after alloimmunization. The pathophysiologic mechanism of this remains unclear. The most common alloantibody specificities were Rh (57%) and Kell (21%) (Table 1). The median interval between 1st RBC transfusion and antibody detection was 10 (0.2-225) months. In 9 cases (6 females) alloantibodies were detected prior to the 1st unit of RBC-transfused. The incidence of RBC alloimmunization reached a plateau at 16% by 100 units of RBC (Fig. 1A), however 80% of antibodies were detectable by 30-40 RBC units transfused. It indicates that most "responders" will form antibodies during the first 30-40 units of RBC transfused. Since most chronically transfused MDS patients do not form RBC alloantibodies it is important from a clinical and resource-utilization standpoint to identify who is at greatest risk of RBC alloimmunization. Multivariate analysis using Cox-regression model was performed. The only factor which was associated with significantly higher risk of RBC alloimmunization was RBC-TD (HR 2.52; p=0.0005). Age, sex, IPSS-R category and number of RBC units transfused did not independently predict alloimmunization rate. Using competing risk analysis, the cumulative incidence of RBC-alloimmunization was significantly higher in RBC-TD group compared to RBC-TI group (p=0.0004; Fig. 1B). Conclusion: RBC-alloimmunization is a substantial risk in MDS patients, especially in RBC-transfusion dependent cases. Extended phenotype matching (D,C,c,E,e and Kell) could have prevented alloantibody formation in 79% of alloimmunized MDS patients. Table 1. Specificity of 155 RBC-alloantibodies Table 1. Specificity of 155 RBC-alloantibodies Disclosures Yeung: Ariad: Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.

Description: Up to 90% of MDS patients require red blood cell (RBC) transfusions. Literature addressing incidence and impact of alloimmunization in MDS is limited. We previously reported that 11% RBC-transfused MDS patients develop alloantibodies and RBC-transfusion requirement increases following alloimmunization (Singhal et al Haematologica 2017). This study aims to assess mechanism of increased RBC transfusion requirement following alloimmunization in MDS patients by comparing RBC-transfusion requirement following single and multiple alloantibodies, and impact of autoantibody on transfusion requirement. Primary MDS (PMDS), oligoblastic acute myeloid leukemia (AML) and therapy-related myeloid neoplasm (t-MN) patients enrolled in the SA-MDS registry (n=1002) between Nov 1991-Jun 2017, followed up for 〉3 months, received at least 1 unit of RBC and did not develop alloantibodies before first RBC transfusion were selected for analysis. Cumulative incidence (CI) of RBC-alloimmunization and clinical impact of alloimmunization including autoantibody formation and change in RBC-transfusion requirements was assessed. We also assessed risk factors for alloimmunization using recursive partitioning and Cox-regression. Seven hundred and sixty-two patients (76%) were eligible for analysis; 584 (76.5%) PMDS, 56 (7.3%) oligoblastic AML and 123 (16%) were t-MN. The median age was 72 years (range 18-97) and 489 (64%) were males. According to the Revised International Prognostic Scoring System (IPSS-R), 44.9% and 54.9% patients were classified as IPSS-R Very low/Low risk and Intermediate/High/Very high risk, respectively. The CI of alloimmunization in RBC-transfused patients was 15% (Fig 1A) and alloantibodies were most commonly against K (32%), E (26%), C (18%), Jka (10%) & Duffy (3%) antigens. Interestingly, 53% (53/99) of alloimmunized patients had single alloantibody while 46% (46/99) had multiple alloantibodies detected simultaneously or subsequently. RBC requirement was significantly higher in alloimmunized compared to non-alloimmunized patients (80±95 vs 41±58, p

Description: Introduction: Although infections are a leading cause of morbidity and mortality in MDS patients, there is limited evidence on causative organisms and resistance patterns in this patient population. This study, the largest series of infection in MDS patients, seeks to comprehensively analyse infection in this cohort. Method: CT scan, microbiology results and hospital admission ICD codes from January 1999 to April 2017 were analysed for 657 MDS patients enrolled in the South Australian MDS (SA-MDS) registry. Cox regression analysis was performed to ascertain risk factors for developing infection. Results: There were 531 primary and 126 therapy-related myeloid neoplasm (t-MN) patients with median age of 69.2 (18-97) years. According to Revised International Prognostic Scoring System (IPSS-R), 44.7% of patients were classified as Intermediate, High and Very High risk. The majority of the cohort (377/657; 57.3%) received best supportive care and 265 had disease modifying therapy including azacitidine (n=142), chemotherapy (n=74) and stem cell transplantation (SCT) (n=25). There were 2450 hospital admissions and 1312(53.5%) were infection-related, in 464/657 patients. The most common sites of infection were lower respiratory tract infections (LRTI) n=449(33.2%), fever with no known source n=356(26.3%) and skin and soft tissue (SSTI; 235, 17.3%). During the study period, 1613/16176 (10%) of microbiology tests were positive. The most common positive tests were blood cultures (494, 30.6%), respiratory viral PCR (227, 14.0%) and bacteriology (other sites; 216, 13.4%). The most common isolates were bacteria (67.3%) followed by viruses (28.1%) and fungi (4.6%). The most common bacteria were gram negative bacilli (GNB); E. coli n=81(12%), Pseudomonas spp. n=64(9%) and Klebsiella spp. n=56(8%), and the most common gram-positive isolates were Staphylococcus aureus n=114(20%) and Enterococcus spp. (37, 7%). There were 192 episodes of bacteraemia in 179 patients. The most common causative organisms were E. coli n=32(16.7%), Klebsiella spp. n=18(9.4%) Pseudomonas spp. n=25(13%), coagulase negative staphylococci n=26(14%), Streptococcus spp. n=22(11%) and Enterococcus spp. n=14(11%). The proportion of GNB bacteremias significantly increased over time (45.8% 1999-2005; 40.0% 2006-2011 and 59.4% 2012-2017 [p=.004]) without increased resistance to commonly used antibiotics. There were 21 enterococcal bacteremias with significant increase in proportion of vancomycin resistant Enterococcus (VRE) after 2011 (p

Description: Background: The management of older patients with Myelodysplastic syndrome (MDS) and Acute Myeloid Leukaemia (AML) is currently based on disease biology and performance status despite the heterogeneity of ageing and the increasingly complex care needs of frail and multi-morbid patients. Performance status scores fail to capture deficits across all the domains of ageing therefore patients that are pre-frail or vulnerable fail to be identified early in their journey. Geriatric assessments have been firmly established in the management of oncological patients but not as yet in haematological malignancies. Aims and Methods: This prospective interventional study was conducted at the Royal Adelaide Hospital. The aim was to determine if deficits in ageing were associated with therapy completion rates and survival. After the treatment decision had been made by the haematologists, consented patients had nurse-led geriatric assessments followed by Geriatrician review in participants with abnormal assessments subjective concerns with interventions implemented. Results: A total of 108 patients were enrolled into the study over a 4 year period. Although only 29 (27%) patients had an Eastern Cooperative Oncology Group score ≥2, 86 (79%) patients had deficits in at least one domain of ageing. Deficits were spread across all domains, including dependence for instrumental activity of daily living (iADL) (n=32, 29%). Patients who were iADL-dependent (3.2±5 vs. 10.8±15; p=0.004), were cognitively impaired (2.8±4 vs. 9.9±15; p=0.010) or had impaired mobility measured by the timed-up and got test (3.3±5 vs. 11.±15; p=0.002), completed significantly less cycles of azacitidine therapy than patients without deficits in these domains (Fig 1A-C). The patients who ceased therapy prematurely (less than 6 cycles) also had significantly poorer overall survival (OS) of patients compared to patients completing at least six cycles of azacitidine. (Fig 1D). Other domains predictive of poorer survival were iADL dependence (HR 4.91; p=0.003) and increased comorbidities (HR 4.41; p=0.004) independent of age and disease factors (n=108) (Fig 2A). Additionally iADL dependence was associated with shortened survival regardless of therapy choice reflecting the frailty of this group of patients - azacitidine (6 vs. 19 months, p=0.002) and supportive care cohorts (28 months vs. not reached, p=0.04; Fig 2B-C). Seventy patients were reviewed by the Geriatrician which led to the identification of a significant degree of multimorbidity (87%) and polypharmacy (73%), which have been shown to negatively impact on morbidity. Interventions and recommendations included changes in medications (57%), investigations for further evaluation of non-oncologic conditions (61%), social support referral including Aged Care Assessment (34%), nutritional support by counselling or referral to dietician (37%), formal cognitive evaluation and management (60%), physical therapy program referral or counselling (39%), referral or shared care with other specialists besides haematology and the primary care provider (26%), and psychologist referral (16%). Conclusion: This study demonstrates that geriatric assessment is feasible and instrumental in identifying geriatric related health issues in a significant proportion of patients compared to the use of performance scores. Deficits associated with ageing are associated with premature cessation of therapy and poorer survival. Geriatric assessments should form part of the assessment of older persons with the aim of reducing adverse outcomes and maintaining quality of life. Disclosures Ross: Celgene: Research Funding; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; BMS: Honoraria. Hiwase:Novartis: Research Funding; Celgene: Research Funding.

Description: Therapy-related myeloid neoplasm (t-MN) is considered to be a direct stochastic complication of chemotherapy and/or radiotherapy for primary cancer or autoimmune diseases. However, genetic predisposition is reported in 8-12% of sporadic adult cancer patients [Lu et al Nature Communication 2015 and Huang et al Cell 2018]. Similarly, genetic predispositions to t-MN have also been reported in limited single institute studies of small numbers of patients [Churpek et al Cancer 2016]. In this study, we performed comprehensive germline and somatic mutation profiling in t-MN using next generation sequencing. Matched germline material was available for 62/194 (32%) patients. Mutation profiling was correlated with clinical features including family history in 194 patients enrolled in the South Australian MDS (SA-MDS) registry and Cleveland Clinic (CC). An in-house well established filtering pipeline was used for identification of somatic mutations. Only variants with Genome Aggregation Database (gnomAD) minor allele frequency (MAF) of ≤0.01% and variant allele frequency (VAF) of ≥35% were selected for further analysis of germline variants. Variants reported in in the Catalogue of Somatic Mutations in Cancer database and MDS/AML were excluded from further analysis. Variants reported pathogenic in Breast Cancer Information Core (BIC) database and Leiden Open Variation Database (LOVD) were retained. Other variants were included if truncating (nonsense, indels, splice alterations), CADD〉20, or predicted deleterious by 〉4/6 scoring algorithms (GERP〉4, PhyloP〉2, SIFT, PolyPhen2, MutationTaster and FATHMM). Forty-one (21%) t-MN patients harbored 45 rare (MAF

Description: RBC-transfusion dependency (RBC-TD) is an independent prognostic factor for poor survival in the WHO classification-based prognostic scoring system (WPSS) for MDS patients. However, WPSS did not include cytopenia, whereas revised International prognostic Scoring System (IPSS-R) includedthree haemoglobincut-offs, which were thought to substitute for RBC-TD. Thus, none of these prognostic scoring systems incorporates both cytopenia and RBC-TD. We aimed to test whether RBC-TD adds prognostic value to the IPSS-R, in addition to that offered by haemoglobin levels at diagnosis. South Australian MDS registry (SA-MDS registry) data were used to derive a prognostic index while Dusseldorf registry (Germany) data was used as a validation cohort. Inclusion criteria for this study were: primary MDS not treated with disease-modifying therapy, bone marrow blasts ≤30% and peripheral blasts ≤20%. RBC TD was defined as at least one unit of packed red cells transfused every eight weeks for four months (mos), according to WPSS classification. In this study IPSS-R was calculated at the time of diagnosis and the RBC-TD was continuously reassessed after diagnosis. In South Australian Registry, the prevalence of RBC-TD at diagnosis was 61/295 (20.7%), while the incidence of RBC-TD during follow-up was 64/234 (27.4%; Table I). The poor prognosis associated with RBC-TD was demonstrated in a series of landmark analyses. The median overall survival (OS) of RBC-TD patients was significantly inferior to RBC transfusion independent (RBC-TI) patients at 6mos (18 vs. 64 months; n=255; p 〈 0.0001), 12mos (24 vs. 71 months; n=231; p 〈 0.0001) and 24mos (40 vs. 87 months; p 〈 0.0001; n=173; Fig 1A-C). Subgroup analysis of IPSS-R Low and Intermediate risk groups also showed inferior OS in RBC-TD compared to RBC-TI within each risk category. The adverse prognosis of RBC-TD was substantiated in multivariate analysis using a Cox-proportional regression model. We tested 46 models and in each of the three models with least Akaike Information Criterion (AIC) or minimum AIC difference RBC-TD wasan independent adverse prognostic marker in addition to age, sex, and IPSS-R variables(Wald test; P