Mortality Rates, Diverse Causes of Death in Polycythemia Vera

The 4-year mortality rate among patients with polycythemia vera (PV) was estimated to be more than 10%, and causes of death are diverse regardless of patient age, according to  results from the final analysis of the REVEAL study (ClinicalTrials.gov Identifier: NCT02252159), the largest prospective and contemporary cohort of patients with PV in the United States. The study results were presented by Brady L. Stein, MD, MHSc, of Northwestern University Feinberg School of Medicine, Chicago, Illinois, at the virtual 62nd American Society of Hematology (ASH) Annual Meeting and Exposition.

“The median survival from a PV diagnosis is estimated to be about 2 decades, but survival in PV has often been evaluated retrospectively, and as a result, granularity with respect to causes of death is often lacking,” said Dr Stein.

REVEAL was a multicenter, noninterventional, prospective observational study of patients with PV treated at 227 US clinical practices (community and academic). The final analysis evaluated characteristics of deceased patients, survival by risk (high-risk defined as age ≥60 years and/or with a thrombotic event history), and causes of death. Clinical characteristics and symptom data were collected at routine care visits until death, withdrawal of consent, or study completion.

Overall, 2510 patients with PV (mean [SD] age at enrollment, 66.3 [12.3] years; 54.2% men) were followed. In total, 244 patients (9.7%) died during the study, and at last follow-up 2266 (90.3%) were alive (mean follow-up duration, 110.3 and 179.4 weeks for patients who died and those who survived, respectively).

On average, patients who died were 77.1 years of age at death and had a mean disease duration of 8.6 years. Patients who died were significantly older at diagnosis (mean age, 68.5 vs 60.2 years; P <.001) and were more likely to have high-risk disease at diagnosis (82.0% vs 59.1%; P <.001) compared with patients who survived.

Comorbid cardiac disorders (41.0% vs 12.1%); other blood and lymphatic system disorders (31.1% vs 18.5% ); vascular disorders (72.1% vs 62.3%); neoplasms (47.5% vs 22.2%); respiratory, thoracic, and mediastinal disorders (55.7% vs 33.4%); and infections (41.0% vs 26.3%; all P <.05) were more frequent in the patients who died compared with those who survived.

Overall survival (OS) probability at 4 years was significantly lower in high-risk patients compared with low-risk patients (86% vs 97%; P <.001). History of thrombotic events prior to study enrollment (hazard ratio [HR], 1.34; 95% CI, 1.00-1.78; P =.0484) and during study enrollment (HR, 2.85; 95% CI, 1.88-4.31; P <.001) was associated with reduced OS.

Of patients with known cause of death (n=175, 72%), thrombotic complications (33.1%) were the most common cause, followed by hematologic malignancy (15.4%), respiratory failure (13.1%), solid tumor (12.0%), infection (10.3%), and bleeding (6.3%). Less common causes of death included organ failure and dementia.

“A higher rate of respiratory disorders observed in the disease population both as a comorbid illness and cause of death has not previously been well characterized in PV mortality studies and does warrant further investigation of whether some patients could have had undiagnosed pulmonary hypertension, which can be associated with myeloproliferative neoplasms,” said Dr Stein.

Disclosure: Some authors have declared affiliations with or received funding from the pharmaceutical industry. Please refer to the original study for a full list of disclosures.

Read more of Hematology Advisor’s coverage of the ASH 2020 meeting by visiting the conference page.

Reference

Stein BL, Patel K, Scherber RM, Yu J, Paranagama D, Miller CB. Mortality and causes of death of patients with polycythemia vera: analysis of the reveal prospective, observational study. Presented at: American Society of Hematology (ASH) 62nd Annual Meeting and Exposition; December 5-8, 2020. Abstract 484.