Prognosis

Life expectancy of patients with polycythaemia vera (PV) is reported to be modestly reduced compared with that of the general population.[14]​ Median overall survival (stratified by age) has been estimated to be:[167]

  • 37 years (age ≤40 years)

  • 22 years (age 41-60 years)

  • 10 years (age > 60 years).

Median overall survival (all ages) for patients with PV was 11.9 years in one study, based on registry data for 10,725 patients diagnosed between 2001 and 2015 (median follow-up 5.8 years). During the study period, 105 (1.0%) PV patients progressed to acute myeloid leukaemia (AML); median time to AML transformation was 4.4 years.[168]

​The most common causes of death in patients with PV are cardiovascular complications (including thrombosis and haemorrhage) and transformation to acute myeloid leukaemia.[55][118]​[121]​​[169]​​​ One population-based study reported that 26.1% of deaths in patients with PV were due to cardiovascular disease, 12.7% due to solid tumours, and 5% related to myeloid cancer.[168]

Prognostic factors

Some studies have shown a correlation between thrombotic risk and leukocytosis in patients with PV; however, uncertainty remains.[56][60][145]

Patients with 'masked PV' may have shorter survival compared with those with overt PV (particularly among those aged >65 years and those with leukocytosis) and higher rates of progression to myelofibrosis and acute leukaemia.[16][17] Delayed/missed recognition and a lower intensity of treatment of masked PV may contribute to worse outcomes.[19]

Mutations in SRSF2, ASXL1, and IDH2 are associated with worse prognosis, although only SRSF2 mutations confer worse survival when taking into account age, WBC count, and thrombosis history.[37][84]

Other factors negatively associated with long-term survival and transformation risk include raised lactate dehydrogenase level, degree of reticulin staining, and JAK2 mutant allele burden.[67]

Prognostic scales

One international study in 1545 patients with PV established risk scores based on age, WBC count, and venous thrombosis history:[14]

  • Low (median survival 27.8 years)

  • Intermediate (median survival 18.9 years)

  • High (median survival 10.9 years).

In this model, 5 points were assigned to age ≥67 years, 2 points to age 57 to 66 years, and 1 point each to leukocyte count ≥15 × 10⁹/L (15 × 10³/microlitre or 15,000/microlitre) and presence of venous thrombosis.

Median survival for the entire study population was projected at 18.9 years, but when the analysis was restricted to the centre with the most mature survival data (44% of patients followed until death), median survival was only 14.1 years.[14]

The Mutation-enhanced International Prognostic Scoring System (MIPSS) is a point-based risk-stratification tool for PV that incorporates the following prognostic factors:[84] 

  • Thrombosis history (1 point)

  • Leukocyte count ≥15,000/microlitre (15 × 10⁹/L or 15 × 10³/microlitre) (1 point)

  • Age >67 years (2 points)

  • Spliceosome mutations (SRSF2) (3 points).

See Criteria.

In the final three-tiered model, median survival was 24 years for low-risk patients (0-1 points), 13.1 years for intermediate-risk patients (2-3 points), and 3.2 years for high-risk patients (≥4 points).[84]

Use of this content is subject to our disclaimer