Polycythaemia vera in young people: an analysis of 58 cases diagnosed before 40 years

Abstract

Over 20 years, 58 cases of PV in young people (46 meeting the full PVSG criteria, 12 with elevated red cell volume and leucocytosis or thrombocytosis, without splenomegaly) were studied and have been followed for periods of 3-24 years. These cases represent approximately 5% of the cases of PV referred to the Department of Nuclear Medicine of St Louis Hospital during this period. They differ from older patients in the initial clinical severity, the short interval between the first symptoms and the diagnosis, frequent presentation with a life-threatening complication (two cases of hepatic vein thrombosis, six thrombotic or haemorrhagic events, six splenectomies, two abortions) and a very enlarged spleen in half the cases. However, after the initial complications, the overall survival is very long (exceeding 70%, even when including the initial complications, at 15 years). The vascular accidents occur exclusively in the phlebotomized patients, the main risk factor being the poor stability of the haematocrit. Only one acute leukaemia was observed among the 14 cases treated by radioactive phosphorus and/or alkylating chemotherapy. The most frequent late complication was evolution towards myelofibrosis. This spent phase seemed to occur earlier in patients treated by phlebotomy. On the basis of this data, we would advise the following therapeutic strategy: phlebotomies, as soon as the diagnosis is established, and a systematic long-term treatment by hydroxyurea with the hope of reducing the number of vascular complications and of delaying the evolution towards the spent phase and the myelofibrosis.

Polycythemia vera: myths, mechanisms, and management

“…145,149,156,239,244,254 Furthermore, in 2 studies, 14% to 15% of patients had a history of a thrombotic event at least 2 years before diagnosis. 244,248 In general, the central nervous system was the most frequent site of thrombosis, 156,244,253,255 arterial thrombosis was more common than venous 156,244,[253][254][255] and the latter was characteristically cerebral or intraabdominal and more frequent in women, 151,194,241 possibly in keeping with their higher incidence of splenomegaly at presentation. 239 Indeed, polycythemia vera was the most common cause of hepatic vein thrombosis in the Western hemisphere.…”

“…149,150 Additionally, it is not widely appreciated that the disease may have different manifestations depending on the age at onset and the patient's sex. 151 Finally, adding to the confusion has been the uncritical acceptance or misuse of terms such as "spent phase" and "postpolycythemic myeloid metaplasia" together with the assumption that the various chronic myeloproliferative disorders are interrelated 152 when in fact proof is lacking that they are. 153 The spent phase of polycythemia vera While it has been clearly established that polycythemia vera can be complicated by anemia, myelofibrosis, and myeloid metaplasia, the frequency with which these complications occur and their clinical significance in the absence of cytotoxic therapy has rarely been ascertained prospectively.…”

Thrombosis in myeloproliferative disorders: pathogenetic facts and speculation

“…16 Thromboses of cerebral sinuses and of splanchnic (portal and hepatic) veins have been repeatedly reported in relatively young female patients. 27,28 Although the relative prevalence of all the other thrombotic complications does not significantly change during the course of the disease, splanchnic vein thromboses are often an early complication and often manifest before diagnosis (Figure 1). The prevalence of a latent MPN in subjects with hepatic vein thrombosis or with extra hepatic portal vein thrombosis has been estimated to range between 40 and 60% of cases.…”

Life expectancy and prognostic factors in the classic BCR/ABL-negative myeloproliferative disorders

“…Similar conclusions have been obtained in the few additional studies focused on the outcome of young patients with PV and ET. [51][52][53][54][55][56][57] The World Health Organization classification, 58 published in 2001, recognized a new entity within the MPDs, the so-called 'prefibrotic' stage of PMF, 32 which would include patients who would have been classified as having ET using the Polycythemia Vera Study Group criteria. 58 Although it has been claimed that patients with 'prefibrotic' PMF had a loss in life expectancy when compared to those with ET, 59 no differences in clinical outcome were observed in a recent study focused on the pathological and clinical distinction between ET and 'prefibrotic' PMF.…”