Susan M. Schwager

DIPSS Plus: A Refined Dynamic International Prognostic Scoring System for Primary Myelofibrosis That Incorporates Prognostic Information From Karyotype, Platelet Count, and Transfusion Status

PURPOSE The Dynamic International Prognostic Scoring System (DIPSS) for primary myelofibrosis (PMF) uses five risk factors to predict survival: age older than 65 years, hemoglobin lower than 10 g/dL, leukocytes higher than 25 × 10(9)/L, circulating blasts ≥ 1%, and constitutional symptoms. The main objective of this study was to refine DIPSS by incorporating prognostic information from karyotype, platelet count, and transfusion status. PATIENTS AND METHODS Mayo Clinic databases for PMF were used to identify patients with available bone marrow histologic and cytogenetic information. RESULTS Seven hundred ninety-three consecutive patients were selected and divided into two groups based on whether or not their referral occurred within (n = 428; training set) or after (n = 365; test set) 1 year of diagnosis. Multivariable analysis identified DIPSS, unfavorable karyotype, platelets lower than 100 × 10(9)/L, and transfusion need as independent predictors of inferior survival. Hazard ratio (HR)-weighted adverse points were assigned to these variables to develop a composite prognostic model using the training set. The model was subsequently validated in the test set, and its application to all 793 patients resulted in median survivals of 185, 78, 35, and 16 months for low, intermediate-1 (HR, 2.2; 95% CI, 1.4 to 3.6), intermediate-2 (HR, 4.9; 95% CI, 3.2 to 7.7), and high-risk groups (HR, 10.7; 95% CI, 6.8 to 16.9), respectively (P < .001). Leukemia-free survival was predicted by the presence of thrombocytopenia or unfavorable karyotype (10-year risk of 31% v 12%; HR, 3.3; 95% CI, 1.9 to 5.6). CONCLUSION DIPSS plus effectively combines prognostic information from DIPSS, karyotype, platelet count, and transfusion status to predict overall survival in PMF. In addition, unfavorable karyotype or thrombocytopenia predicts inferior leukemia-free survival.

TET2 mutations and their clinical correlates in polycythemia vera, essential thrombocythemia and myelofibrosis

High-throughput DNA sequence analysis was used to screen for TET2 mutations in bone marrow-derived DNA from 239 patients with BCR-ABL-negative myeloproliferative neoplasms (MPNs). Thirty-two mutations (19 frameshift, 10 nonsense, 3 missense; mostly involving exons 4 and 12) were identified for an overall mutational frequency of ∼13%. Specific diagnoses included polycythemia vera (PV; n=89), essential thrombocythemia (ET; n=57), primary myelofibrosis (PMF; n=60), post-PV MF (n=14), post-ET MF (n=7) and blast phase PV/ET/MF (n=12); the corresponding mutational frequencies were ∼16, 5, 17, 14, 14 and 17% (P=0.50). Mutant TET2 was detected in ∼17 and ∼7% of JAK2V617F-positive and -negative cases, respectively (P=0.04). However, this apparent clustering of the two mutations was accounted for by an independent association between mutant TET2 and advanced age; mutational frequency was ∼23% in patients ⩾60 years old versus ∼4% in younger patients (P<0.0001). The presence of mutant TET2 did not affect survival, leukemic transformation or thrombosis in either PV or PMF; a correlation with hemoglobin <10 g per 100 ml in PMF was noted (P=0.05). We conclude that TET2 mutations occur in both JAK2V617F-positive and -negative MPN, are more prevalent in older patients, display similar frequencies across MPN subcategories and disease stages, and hold limited prognostic relevance.

JAK2V617F mutation in essential thrombocythaemia: clinical associations and long-term prognostic relevance

Clinical correlates and long‐term prognostic relevance of the JAK2V617F mutation was studied in 150 patients with essential thrombocythaemia (ET) from a single institution and followed for a median of 11·4 years. During this period, thrombotic complications were documented in 62 patients (41·3%) and transformation into acute myeloid leukaemia (AML), polycythaemia vera (PV), or myelofibrosis with myeloid metaplasia (MMM) occurred in 4 (2·7%), 8 (5·3%), and 15 (10%) patients, respectively. JAK2V617F was detected in either archived bone marrow or blood cells from 73 patients (48·7%) but none were homozygous for the mutant allele. Parameters at diagnosis that were significantly associated with the presence of JAK2V617F included advanced age and higher counts of both haemoglobin and leucocytes. During follow‐up, patients with the mutation were more likely to transform into PV but the incidences of AML, MMM, or thrombotic events were similar between patients with and without the mutation. Multivariate analysis identified advanced age, higher haemoglobin level, and thrombosis history but not the presence of JAK2V617F as independent predictors of inferior survival. Therefore, although the presence of JAK2V617F in ET appears to promote a PV phenotype, it might not carry treatment‐relevant information.

Essential Thrombocythemia Beyond the First Decade: Life Expectancy, Long-term Complication Rates, and Prognostic Factors

OBJECTIVE To describe the long-term natural history of essential thrombocythemia (ET) in terms of life expectancy, risk of disease transformation Into a more aggressive myeloid disorder, and prognostic factors for both survival and disease complications. PATIENTS AND METHODS The study population consisted of a consecutive cohort of patients seen at the Mayo Clinic In Rochester, Minn, in whom a diagnosis of ET was established before 1992, thus allowing a minimum of 10 years of potential follow-up. The conventional criteria-based diagnosis was confirmed by bone marrow biopsy in all Instances. RESULTS A total of 322 patients were studied (median age, 54 years; median follow-up, 13.6 years). With a median survival time of 18.9 years, survival in the first decade of disease was similar to that of the control population (risk ratio, 0.72; 95% confidence interval, 0.50-0.99) but became significantly worse thereafter (risk ratio, 2.21; 95% confidence Interval, 1.74-2.76). Multivariable analysis identified age at diagnosis of 60 years or older, leukocytosis, tobacco use, and diabetes mellitus as Independent predictors of poor survival. A 2-variable model based on an age cutoff of 60 years and leukocyte count of 15 x 10(9)/L resulted in 3 risk groups with significant difference in survival. In addition, age at diagnosis of 60 years or older, leukocytosis, and history of thrombosis were independent predictors of major thrombotic events. The risk of leukemic or any myeloid disease transformation was low in the first 10 years (1.4% and 9.1%, respectively) but increased substantially in the second (8.1% and 28.3%, respectively) and third (24.0% and 58.5%, respectively) decades of the disease. CONCLUSION Life expectancy in patients with ET is significantly worse than that of the control population. Leukocytosis is identified as a novel independent risk factor for both inferior survival and thrombotic events.

The JAK2V617F tyrosine kinase mutation in myelofibrosis with myeloid metaplasia : lineage specificity and clinical correlates

An association between an activating JAK2 mutation (JAK2V617F) and BCR/ABL‐negative myeloproliferative disorders was recently reported in multiple simultaneous publications. In the current study, mutation analysis for JAK2V617F was performed in peripheral blood mononuclear cells (PBMC) from 157 patients with myelofibrosis with myeloid metaplasia (MMM) including 117 with agnogenic (AMM), 22 with postpolycythaemic (PPMM), and 18 with post‐thrombocythaemic (PTMM) myeloid metaplasia. The detection rate for JAK2V617F was significantly higher in PPMM (91%; homozygous in 18%) compared with either AMM (45·3%; homozygous in 2·6%) or PTMM (38·9%; homozygous in 11·1%). Concomitant analysis in granulocytes (n = 57) and CD34+ cells (n = 25) disclosed a higher incidence of homozygous JAK2V617F mutation but the overall mutation rate was similar to that obtained from PBMC. JAK2V617F was not detected in DNA derived from T cells (n = 19). In AMM, the presence of JAK2V617F was associated with an older age at diagnosis and a history of thrombosis or pruritus. Multivariate analysis identified only age and the Dupriez prognostic score as independent prognostic factors; JAK2V617F had no prognostic significance. In conclusion, JAK2V617F is a myeloid lineage‐specific event, its incidence in MMM is significantly higher with an antecedent history of polycythaemia vera (PV), and its presence in AMM does not affect prognosis but is associated with PV‐characteristic clinical features.

The clinical phenotype of wild-type, heterozygous, and homozygous JAK2V617F in polycythemia vera

Several studies have recently reported on the occurrence of a JAK2V617F mutation in myeloid cells from the majority of patients with polycythemia vera (PV). The clinical relevance of this novel observation currently is under study.

Risk stratification for survival and leukemic transformation in essential thrombocythemia: a single institutional study of 605 patients.

Unlike the case with thrombosis, prognostic models for survival and leukemic transformation (LT) in essential thrombocythemia (ET) are not available. Among 605 patients with ET seen at our institution and followed for a median of 84 months, 155 died and LT was documented in 20 patients (3.3%). In a multivariable analysis, hemoglobin level below normal (females<120 g/l; males<135 g/l) was identified as an independent risk factor for both inferior survival and LT. Additional risk factors for survival included age ⩾60 years, leukocyte count⩾15 × 109/l, smoking, diabetes mellitus and thrombosis. For LT, platelet count⩾1000 × 109/l but not cytoreductive therapy was flagged as an additional independent risk factor. In fact, four of the 20 patients (20%) with LT were untreated previously. We used the above information to construct prognostic models that effectively discriminated among low-, intermediate- and high-risk groups with respective median survivals of 278, 200 and 111 months (P<0.0001), and LT rates of 0.4, 4.8 and 6.5% (P=0.0009) respectively. Presence of JAK2V617F did not impact either survival or LT and mutational frequency was similar among the different risk groups.

The Myelofibrosis Symptom Assessment Form (MFSAF): An evidence-based brief inventory to measure quality of life and symptomatic response to treatment in myelofibrosis

Quality of life (QoL) in patients with myelofibrosis (MF) is severely compromised by severe constitutional symptoms (i.e. fatigue, night sweats, fever, weight loss), pruritus, and symptoms from frequently massive hepatosplenomegaly. Given that no current instrument of patient reported outcomes (PRO) exists that covers the unique spectrum of symptomatology seen in MF patients, we sought to develop a new PRO instrument for MF patients for use in therapeutic clinical trials. Utilizing data from an international Internet-based survey of 458 patients with MF we created a 20-item instrument (MFSAF: Myelofibrosis Symptom Assessment Form) which measures the symptoms reported by >10% of MF patients and includes a measure of QoL. We subsequently validated the MFSAF in a prospective trial of MF patients involving patient and provider feedback, as well as comparison to other validated instruments used in cancer patients. The MFSAF results were highly correlated with other instruments, judged comprehensive and understandable by patients, and should be considered for evaluation of MF symptoms in therapeutic trials.

Palliative goals, patient selection, and perioperative platelet management: outcomes and lessons from 3 decades of splenectomy for myelofibrosis with myeloid metaplasia at the Mayo Clinic.

Although splenectomy may palliate massive splenomegaly in patients with myelofibrosis with myeloid metaplasia, this procedure carries significant risks. The authors retrospectively analyzed their experience with splenectomy over the course of 30 years to analyze the impact of improved techniques, antimicrobials, and aggressive postoperative control of platelet counts on outcome.

Comorbid conditions and survival in unselected, newly diagnosed patients with chronic lymphocytic leukemia

Little is known about the spectrum or frequency of comorbidities in patients with chronic lymphocytic leukemia (CLL). We investigated the prevalence and prognostic implications of comorbidities in patients with newly diagnosed CLL. Local/non-referred patients with CLL evaluated by a hematologist at Mayo Clinic within 1 year of diagnosis were eligible for this retrospective review. Of 1195 individuals evaluated for newly-diagnosed CLL between 1995 and 2006, 373 (31%) were local/non-referred. At diagnosis, 89% of these patients had one or more comorbidities, and 46% had at least one major comorbidity. Twenty-six percent of patients failed to meet NCI working group guidelines to participate in a clinical trial. On multi-factor analysis, Rai risk category (1.39 per each risk category increase; p < 0.0001) and age (1.056 per year increase; p < 0.0001) were the only factors associated with overall survival. We conclude that, although common, comorbid conditions are less important than age and stage in predicting prognosis in newly diagnosed patients with CLL. Clinical trials evaluating treatments that are designed to be tolerated by patients who do not meet traditional clinical trial eligibility criteria are needed.