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1300 Part X: Malignant Myeloid Diseases Chapter 84: Polycythemia Vera 1301

THE SPENT PHASE 1.0
Sometimes after only a few years and usually after 15 years or more, 0.9
erythrocytosis in patients with PV gradually abates in the absence of 0.8
iron deficiency, phlebotomy requirements decrease and cease, and ane- 0.7 N=503
mia develops. During this “spent” phase of the disease, marrow fibrosis 0.6 Medain survival 27.8 years
becomes more marked and the spleen often becomes greatly enlarged Survival 0.5
(see Fig. 84–2A). Instead of phlebotomies, transfusions or erythropoi- 0.4
etin may be required in such patients. The platelet count may remain 0.3
255
high or may decline, even to pronounced thrombocytopenic levels.
N=568
Marked leukopenia or leukocytosis may occur, and immature granulo- 0.2 Median survival 10.9 years N=474
HR 10.7; 95% CI 7.7-15.0
cytes may appear in the blood. At this point, the disease closely mimics 0.1 Median survival 18.9 years
HR 3.7; 95% CI 2.6-5.2
PMF (Chap. 86) and is termed post-PV MF. Treatment of this phase 0.0
of the disease is difficult and requires the judicious use of a combina- 0 10 20 30 40
tion of therapeutic approaches, including HU, erythropoiesis-stimu- Years
lating drugs, transfusions, JAK2 inhibitors, and/or allogeneic stem cell Figure 84–3. Survival of PV patients stratified by prognostic low-risk
transplantation. (blue), intermediate-risk (green), and high-risk (red) groups. Patients are
scored based on three risk criteria: venous thrombosis (1 point), a leu-
9
Splenectomy kocyte count ≥15 × 10 /L (1 point), and age (≥67 years: 5 points, 57–66
Splenectomy may be warranted (see Fig. 84–2B), particularly in patients years: 2 points). The sum of these points classifies patients as prognostic
with severe fatigue and cytopenias, and in those where a greatly enlarged low risk (0 points), intermediate risk (1–2 points) or high risk (≥3 points).
spleen produces physical discomfort and postprandial fullness. How- (Reproduced with permission from Tefferi A, Rumi E, Finazzi G, et al: Survival
256
and prognosis among 1545 patients with contemporary polycythemia vera:
ever, a large Mayo Clinic series reported significant morbidity and mor- An international study. Leukemia 27(9):1874–1881, 2013.)
tality associated with splenectomy at this stage of the disease. 257
reduced survival of PV patients compared to controls. A recent study
4
Hematopoietic Stem Cell Transplantation of 1545 patients by the IWG-MRT found that survival for PV patients
Nonmyeloablative allogeneic stem cell transplantation should be con- was negatively correlated to leukocytosis, older age, venous thrombosis,
sidered for otherwise healthy PV patients in the spent phase, even in and atypical karyotype. The median overall survival ranged from 10.9
the seventh decade of life (Chap. 23). 255,258,259 Transplantation is the and 27.8 years for different PV prognostic risk groups (Fig. 84–3). 190
treatment of choice in patients with early signs of MDS/AML transfor-
mation, and the only treatment offering the possibility of a cure. The REFERENCES
260
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