The impact of peripheral blood values and bone marrow findings on prognosis for patients with essential thrombocythemia and polycythemia vera.

The Philadelphia chromosome-negative (Ph-) chronic myeloproliferative neoplasms include the three well-known clinical entities polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). Over time, patients with ET and PV may develop myelofibrosis (MF), and all three entities carry a risk of transformation into acute myeloid leukemia (AML). In a population-based survey during 1983-1999, we studied a total of 358 patients who were diagnosed with ET and PV in the city of Gothenburg, Sweden. At the time of diagnosis, evaluable bone marrow biopsy material was available from 280 of these patients. The current work was aimed at investigating the impact of peripheral blood counts, spleen size, and bone marrow biopsy findings at diagnosis on long-term survival and the risk of development of AML or MF in this well-defined unselected population. The variables evaluated were venous blood hemoglobin concentration, packed cell volume, white blood cell count, platelet count, and splenic enlargement; as to bone marrow biopsies, interest was focused on reticulin content, focal or generalized collagen formation, bone marrow cellularity, and megakaryocyte profile number. Over the median observation time of 15 yr, the patients with ET did not demonstrate any significant difference as to survival compared to the normal Swedish population (hazard ratio, 1.23; 95% confidence interval, 0.97-1.51; p= 0.089). The patients with PV, on the other hand, had a significantly shorter survival compared to general population (hazard ratio, 1.66; 95% confidence interval, 1.38-1.99; p< 0.001). A lower hemoglobin concentration at diagnosis of ET predicted poorer survival (p =0.0281), whereas patients with PV with splenic enlargement at diagnosis had a shorter survival (p =0.037). In the patients with ET, the risk of transformation to either MF or AML was significantly associated with low hemoglobin concentration and high white cell count at diagnosis (p =0.0037 and 0.0306, respectively). An increased reticulin content and hypercellularity in the bone marrow at diagnosis were also independent risk factors (p =0.0359 and 0.0103, respectively). The risk of transformation in patients with PV was significantly associated with splenic enlargement and increase in bone marrow reticulin content (p =0.0028 and 0.0164, respectively).

The incidence and survival of acute de novo leukemias in Estonia and in a well-defined region of western Sweden during 1997-2001: a survey of patients aged 16-64 years.

BACKGROUND: In a recent retrospective study, we investigated the incidence and survival of de novo acute leukemia (AL) patients aged 16-64 years over three 5-year periods (1982-1996) in Estonia and in the Western Swedish Health Care Region. The incidence rates were similar in the two countries, but the survival data were highly different. Thus, relative survival at 5 years for de novo AL patients in Estonia was virtually negligible, whereas the corresponding figures for the Swedish patients increased from 20.3 to 38.9% during the study period. AIM: To prospectively compare the results for incidence and outcome of de novo AL between the two countries during 1997-2001. RESULTS: Incidence rates for de novo AL were lower in Estonia than in western Sweden but not significantly so. However, the survival for de novo AL patients in Estonia had improved considerably, with the relative survival at 5 years being 16.4%; such improvement was particularly seen in acute myeloid leukemia patients. For the Swedish patients, no change in survival was recorded. CONCLUSION: In Estonia, a remarkable improvement in outcome for young de novo AL patients was seen after 1996. Nevertheless, relative survival for the Estonian patients had still not reached the levels found in the Swedish cohort.

The incidence and survival of acute de novo leukaemias in Estonia and in a well defined region of Western Sweden during 1982-1996: a survey of patients aged 16-64 years.

In the present work the incidence and survival of acute de novo leukaemias in two neighbouring countries, were studied retrospectively over three 5-year periods, 1982-1996. The aim was to compare the above variables, particularly with respect to political/socio-economic and environmental factors, in a well defined area of Sweden, the so-called Western Swedish Health Care Region, with Estonia. Population-wise the Western Swedish Region and Estonia are very similar; area-wise they are also well comparable. The present report covers only patients diagnosed between the ages of 16-64 years. The number of acute de novo leukaemias in the two regions was quite similar (Western Sweden n = 282 and Estonia n = 237). The age standardized incidence rate regarding total acute de novo leukaemias was slightly lower in Estonia than in Western Sweden (1.49/100,000 inhabitants/year for Estonia and 1.76 for Sweden, respectively), the difference being not statistically significant. However, the survival data for the two countries were highly different (P < 0.001). Thus, the relative survival for the total group of patients aged 16-64 years in Estonia at 1 year was 20.7% and at 5 years 3.6%, respectively. The corresponding figures for the Swedish patients were considerably higher, 65.2 and 29.4%, respectively. Further, the 5 year survival significantly (P < 0.05) increased for the Swedish patients over the 3 consecutive 5-year periods. No such improvement was recorded for the Estonian patients.

Sequential population-based studies over 25 years on the incidence and survival of acute de novo leukemias in Estonia and in a well-defined region of western Sweden during 1982-2006: a survey of patients aged ≥65 years.

Estonia regained independence in 1991 after five decades of occupation by the Soviet Union. The present population-based survey was carried out over five consecutive 5-year study periods (1982-2006) on the incidence and survival of de novo acute leukemia patients aged ≥65 years at diagnosis in Estonia and in a well-defined area in western Sweden. During the study period of retrospective work (1982-1996), the first 10 years were carried out while Estonia was still under the mentorship of the Soviet Union. Over these years, Estonian hematologists did not have access to therapeutic measures readily available to Swedish hematologists, and the results for survival for western Swedish patients with acute myeloid leukemia (AML) far exceeded those of their Estonian counterparts. However, the results for acute lymphoblastic leukemia were equally dismal in the two countries. Subsequent prospective population-based studies were carried out during the years 1997-2006. A gradual improvement as to long-term relative survival of the Estonian AML patients was observed. When studying 2002-2006, no difference as regards relative survival at 5 years was anymore present between the two countries. Over the first 20 years of our population-based studies, it was repeatedly observed that the age-standardized incidence rate particularly for de novo AML was considerably higher for the western Swedish as compared to the Estonian cohorts. During the last 5-year study period (2002-2006), no such difference between the two countries was present, indicating that some true changes in the reporting procedure in Estonia had occurred.

The incidence and survival of acute de novo leukemias in Estonia and in a well-defined region of western Sweden during 1997-2001: a survey of patients aged >or=65 years.

BACKGROUND: In a recently published retrospective population-based study over three 5-year periods (1982-1996) we investigated the outcome for de novo acute leukemia (AL) patients aged >or=65 years at diagnosis in Estonia (a country that had been occupied by the Soviet Union over 5 decades) and in the so-called Western Swedish Health Care Region. The age-standardized yearly incidence rates regarding the total number of de novo AL was 5.3/100000 inhabitant for Estonia and 8.0 for Sweden, this difference being statistically significant merely as regards acute myeloid leukemia (AML). The relative survival for the total cohort of de novo AL as well as for de novo AML was significantly longer (p<0.001) for Swedish as compared to Estonian patients. METHODS: In view of the miserable outcome for the Estonian patients we decided to prospectively compare the results for incidence and outcome of de novo AL between the two countries. RESULTS: The present report covers the first 5-year period comprising 1997-2001 and deals only with patients aged >or=65 years at diagnosis. The age-adjusted annual incidence rates for de novo AML were lower in Estonia (6.4/100000) than in Sweden (9.2/100000) but not significantly so. The present results also show that the outcome for the Estonian AML patients had improved considerably over the study period; thus, at no time point, i.e., at 1, 3 and 5 years did relative survival between the two countries differ significantly. CONCLUSION: Yet, as compared to the Swedish cohort relative survival for the Estonian patients did still not reach an acceptable level.

An elevated venous haemoglobin concentration cannot be used as a surrogate marker for absolute erythrocytosis: a study of patients with polycythaemia vera and apparent polycythaemia.

The diagnosis of polycythaemia vera (PV) has been established upon sets of clinical criteria, which require the presence of absolute erythrocytosis (AE). The most recent clinical criteria for PV, published by the World Health Organization (WHO) in 2001, also required AE, and stated that the measured red cell mass (RCM) could be replaced by a surrogate marker for AE; a haemoglobin (Hb) value of >18.5 g/dl in males and >16.5 g/dl in females. The present study evaluated the potential of venous haematocrit (Hct) and Hb values as possible surrogate markers for AE in a series of 77 consecutive patients with PV and 66 patients with apparent polycythaemia (AP), in all of whom the RCM had been previously determined. In only 35% of the male PV patients would Hb values >18.5 g/dl indicate the presence of AE. Conversely, 14% of male AP patients would be misdiagnosed as having AE. A Hb > 16.5 g/dl would predict the presence of AE in 63% of the female PV patients, but 35% of female AP cases would be misdiagnosed as having AE. However, when the Hct was > or =0.60 an AE was always present, and this was true for both male and female subjects.

Red cell mass, spleen size and plasma erythropoietin in polycythaemia vera and apparent polycythaemia.

Most frequently, an elevated packed cell volume (PCV) value arouses the suspicion of a polycythaemic state. The aim of the present work was to assess a few readily available variables which could help the clinician to differentiate between polycythaemia vera (PV) and apparent polycythaemia (AP). During a 5-year period, 31 consecutive newly diagnosed patients with PV were identified, and during a 4-year period 38 consecutive subjects were considered to be afflicted with AP. In each subject: (i) the red cell mass (RCM) and plasma volume were measured, (ii) the spleen size was assessed using gamma-camera imaging, and (iii) the plasma erythropoietin (EPO) concentration was determined. The diagnosis of PV was based upon recently proposed criteria. By definition, all PV patients had absolute erythrocytosis, i.e. the RCM was greater than 25% above the mean normal predicted value for the individual. There was no statistical difference between the plasma volumes for PV and AP patients. However, the mean measured/predicted plasma volume for subjects with AP was significantly lower than the mean for PV. The means for spleen scan areas (posterior and left lateral projections) for AP patients were identical to the mean reference values for our laboratory. As compared to AP, in PV the spleen scan areas were significantly increased, and the lateral spleen scan area was significantly larger than the posterior area. It was also shown that, in contrast to AP, both spleen scan areas were significantly larger in male than in female PV patients. All PV patients had plasma EPO concentrations below the lower reference limit, and in 68% of the patients undetectable EPO concentrations were present. Most AP patients (84%) had EPO values within the reference range; 8% had slightly subnormal, but not undetectable, plasma EPO levels.

The presence of a significant association between elevated PRV-1 mRNA expression and low plasma erythropoietin concentration in essential thrombocythaemia.

Approximately 45% of newly diagnosed patients with essential thrombocythaemia (ET) demonstrate subnormal plasma erythropoietin (EPO) concentrations, which constitutes a risk factor for occlusive vascular events. In 58 ET patients, a possible association between polycythaemia rubra vera-1 (PRV-1) overexpression and subnormal plasma EPO was investigated, which was always measured prior to the institution of platelet lowering agents. At the time when PRV-1 expression was measured, 28 of 58 (48%) ET patients had received platelet lowering treatment. PRV-1 expression was measured by quantitative real-time reverse transcription-polymerase chain reaction assay of mRNA extracted from purified peripheral blood buffy coat. The cycle threshold (CT) value of PRV-1 was determined and was divided with the CT value for the housekeeping GAPDH gene transcript. A quotient <0.93 was defined as PRV-1 positive. Of the ET patients 12 of 58 (21%) were PRV-1 positive and 19 of 58 (33%) demonstrated subnormal plasma EPO. In the 58 ET patients there was a significant association between low plasma EPO and PRV-1 positive results (P = 0.001). The 30 ET patients who had not received any platelet lowering treatment showed a significant (P = 0.005) relation between PRV-1 positivity and subnormal plasma EPO. No such relationship was present in the 28 ET patients who had received prior treatment with the above drugs (P = 0.147).