Risk for Arterial and Venous Thrombosis in Patients With Myeloproliferative Neoplasms: A Population-Based Cohort Study.

Background: Patients with myeloproliferative neoplasms (MPNs) are reported to be at increased risk for thrombotic events. However, no population-based study has estimated this excess risk compared with matched control participants. Objective: To assess risk for arterial and venous thrombosis in patients with MPNs compared with matched control participants. Design: Matched cohort study. Setting: Population-based setting in Sweden from 1987 to 2009, with follow-up to 2010. Patients: 9429 patients with MPNs and 35 820 matched control participants. Measurements: The primary outcomes were rates of arterial and venous thrombosis. Flexible parametric models were used to calculate hazard ratios (HRs) and cumulative incidence with 95% CIs. Results: The HRs for arterial thrombosis among patients with MPNs compared with control participants at 3 months, 1 year, and 5 years were 3.0 (95% CI, 2.7 to 3.4), 2.0 (CI, 1.8 to 2.2), and 1.5 (CI, 1.4 to 1.6), respectively. The corresponding HRs for venous thrombosis were 9.7 (CI, 7.8 to 12.0), 4.7 (CI, 4.0 to 5.4), and 3.2 (CI, 2.9 to 3.6). The rate was significantly elevated across all age groups and was similar among MPN subtypes. The 5-year cumulative incidence of thrombosis in patients with MPNs showed an initial rapid increase followed by gentler increases during follow-up. The HR for venous thrombosis decreased during more recent calendar periods. Limitation: No information on individual laboratory results or treatment. Conclusion: Patients with MPNs across all age groups have a significantly increased rate of arterial and venous thrombosis compared with matched control participants, with the highest rates at and shortly after diagnosis. Decreases in the rate of venous thrombosis over time likely reflect advances in clinical management. Primary Funding Source: The Cancer Research Foundations of Radiumhemmet, Blodcancerfonden, the Swedish Research Council, the regional agreement on medical training and clinical research between Stockholm County Council and Karolinska Institutet, the Adolf H. Lundin Charitable Foundation, and Memorial Sloan Kettering Cancer Center.

Incidence and risk factors for suicide and attempted suicide following a diagnosis of hematological malignancy.

Solid tumors are associated with an increased risk of suicide, however, there is limited detailed information on the risk of suicide in patients with hematological malignancies. Therefore, we conducted a population-based study including 47,220 patients with hematological malignancies (diagnosed 1992-2006) and their 235,868 matched controls to define the incidence and risk factors for suicide and suicide attempt. Information on suicides, suicide attempts, and preexisting psychiatric disorders was obtained from Swedish registers and individual medical records. There was a twofold increased (hazard ratio [HR] = 1.9, 95% confidence interval 1.5-2.3, P < 0.0001) risk of suicide/suicide attempt during the first 3 years after diagnosis in patients with hematological malignancies compared to matched controls. Of all hematological malignancies, multiple myeloma was associated with the highest risk (HR = 3.4; 2.3-5.0, P < 0.0001). Patients with a preexisting psychiatric disorder were at a very high risk of suicide and suicide attempt (HR = 23.3; 16.6-32.6, P < 0.0001), regardless of type of hematological malignancy. Among patients who committed suicide, 19% were in a palliative phase and 44% were in remission with no active treatment. In conclusion, the risk of suicide and suicide attempt is elevated in patients with hematological malignancies. Certain high-risk patients may benefit from early detection and preventive measures.

Risk and Cause of Death in Patients Diagnosed With Myeloproliferative Neoplasms in Sweden Between 1973 and 2005: A Population-Based Study.

PURPOSE: Myeloproliferative neoplasms (MPNs) are associated with a shortened life expectancy. We assessed causes of death in patients with MPN and matched controls using both relative risks and absolute probabilities in the presence of competing risks. PATIENTS AND METHODS: From Swedish registries, we identified 9,285 patients with MPN and 35,769 matched controls. A flexible parametric model was used to estimate cause-specific hazard ratios (HRs) of death and cumulative incidence functions, each with 95% CIs. RESULTS: In patients with MPN, the HRs of death from hematologic malignancies and infections were 92.8 (95% CI, 70.0 to 123.1) and 2.7 (95% CI, 2.4 to 3.1), respectively. In patients age 70 to 79 years at diagnosis (the largest patient group), the HRs of death from cardiovascular and cerebrovascular disease were 1.5 (95% CI, 1.4 to 1.7) and 1.5 (95% CI, 1.3 to 1.8), respectively; all were statistically significantly elevated compared with those of controls. In the same age group, no difference was observed in the 10-year probability of death resulting from cardiovascular disease in patients with MPN versus controls (16.8% v 15.2%) or cerebrovascular disease (5.6% v 5.2%). In patients age 50 to 59 years at diagnosis, the 10-year probability of death resulting from cardiovascular and cerebrovascular disease was elevated, 4.2% versus 2.1% and 1.9% versus 0.4%, respectively. Survival in patients with MPN increased over time, mainly because of decreased probabilities of dying as a result of hematologic malignancies, infections, and, in young patients, cardiovascular disease. CONCLUSION: Patients with MPN had an overall higher mortality rate than that of matched controls, primarily because of hematologic malignancy, infections, and vascular events in younger patients. Evidently, there is still a need for effective disease-modifying agents to improve patient outcomes.

Familial aggregation of acute myeloid leukemia and myelodysplastic syndromes.

PURPOSE: Apart from rare pedigrees with multiple cases of acute myeloid leukemia (AML), there is limited data on familial aggregation of AML and myelodysplastic syndromes (MDSs) in the population. PATIENTS AND METHODS: Swedish population-based registry data were used to evaluate risk of AML, MDS, and other malignancies among 24,573 first-degree relatives of 6,962 patients with AML and 1,388 patients with MDS compared with 106,224 first-degree relatives of matched controls. We used a marginal survival model to calculate familial aggregation. RESULTS: AML and/or MDS did not aggregate significantly in relatives of patients with AML. There was a modest risk ratio (RR, 1.3; 95% CI, 0.9 to 1.8) in myeloproliferative/myeloid malignancies combined. The risks for any hematologic or any solid tumor were modestly but significantly increased. Relatives of patients with MDS did not show an increased risk for any hematologic tumors. In contrast, we found a significantly increased risk (RR, 6.5; 95% CI, 1.1 to 38.0) of AML/MDS and of all myeloid malignancies combined (RR, 3.1; 95% CI, 1.0 to 9.8) among relatives of patients diagnosed at younger than age 21 years. CONCLUSION: We did not find evidence for familial aggregation of the severe end of the spectrum of myeloid malignancies (AML and MDS). The risks of myeloproliferative neoplasms were modestly increased with trends toward significance, suggesting a possible role of inheritance. In contrast, although limited in sample size, relatives of young patients with AML were at increased risk of AML/MDS, suggesting that germline genes may play a stronger role in these patients. The increased risk of all hematologic malignancies and of solid tumors among relatives of patients with AML suggests that genes for malignancy in general and/or other environmental factors may be shared.

Chronic immune stimulation might act as a trigger for the development of acute myeloid leukemia or myelodysplastic syndromes.

PURPOSE: Patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) often present with infections, but there are little data to assess whether a personal history of selected infections may act as pathogenic triggers. To additionally expand our knowledge on the role of immune stimulation in the causation of AML and MDS, we have conducted a large, population-based study to evaluate the risk of AML and MDS associated with a prior history of a broad range of infections or autoimmune diseases. PATIENTS AND METHODS: By using population-based central registries in Sweden, we included 9,219 patients with AML, 1,662 patients with MDS, and 42,878 matched controls. We used logistic regression to calculate odds ratios (ORs) and 95% CIs for the association of AML or MDS with infectious and/or autoimmune diseases. RESULTS: Overall, a history of any infectious disease was associated with a significantly increased risk of both AML (OR, 1.3; 95% CI, 1.2 to 1.4) and MDS (OR, 1.3; 95% CI, 1.1 to 1.5). These associations were significant even when we limited infections to those occurring 3 or more years before AML/MDS. A previous history of any autoimmune disease was associated with a 1.7-fold (95% CI, 1.5 to 1.9) increased risk for AML and 2.1-fold (95% CI, 1.7 to 2.6) increased risk for MDS. A large range of conditions were each significantly associated with AML and MDS. CONCLUSION: Our novel findings indicate that chronic immune stimulation acts as a trigger for AML/MDS development. The underlying mechanisms may also be due to a common genetic predisposition or an effect of treatment for infections/autoimmune conditions.

Treatment-related risk factors for transformation to acute myeloid leukemia and myelodysplastic syndromes in myeloproliferative neoplasms.

PURPOSE: Patients with myeloproliferative neoplasms (MPNs), including polycythemia vera, essential thrombocythemia, and primary myelofibrosis, have a propensity to develop acute myeloid leukemia (AML) and myelodysplastic syndromes (MDSs). Using population-based data from Sweden, we assessed the role of MPN treatment and subsequent AML/MDS risk with special focus on the leukemogenic potential of hydroxyurea (HU). METHODS: On the basis of a nationwide MPN cohort (N = 11,039), we conducted a nested case-control study, including 162 patients (153 and nine with subsequent AML and MDS diagnosis, respectively) and 242 matched controls. We obtained clinical and MPN treatment data for all patients. Using logistic regression, we calculated odds ratios (ORs) as measures of AML/MDS risk. RESULTS: Forty-one (25%) of 162 patients with MPNs with AML/MDS development were never exposed to alkylating agents, radioactive phosphorous (P(32)), or HU. Compared with patients with who were not exposed to HU, the ORs for 1 to 499 g, 500 to 999 g, more than 1,000 g of HU were 1.5 (95% CI, 0.6 to 2.4), 1.4 (95% CI, 0.6 to 3.4), and 1.3 (95% CI, 0.5 to 3.3), respectively, for AML/MDS development (not significant). Patients with MPNs who received P(32) greater than 1,000 MBq and alkylators greater than 1 g had a 4.6-fold (95% CI, 2.1 to 9.8; P = .002) and 3.4-fold (95% CI, 1.1 to 10.6; P = .015) increased risk of AML/MDS, respectively. Patients receiving two or more cytoreductive treatments had a 2.9-fold (95% CI, 1.4 to 5.9) increased risk of transformation. CONCLUSION: The risk of AML/MDS development after MPN diagnosis was significantly associated with high exposures of P(32) and alkylators but not with HU treatment. Twenty-five percent of patients with MPNs who developed AML/MDS were not exposed to cytotoxic therapy, supporting a major role for nontreatment-related factors.