Classic myeloproliferative neoplasms in Singapore: A population-based study on incidence, trends, and survival from 1968 to 2017

Abstract

Background: Current descriptive epidemiological information on classic myeloproliferative neoplasms (MPNs) is incomplete. Published data among Asian population are particularly sparse.

Methods: We conducted a large population-based study to determine the incidence rates and survival patterns of MPN reported to the Singapore Cancer Registry during the period 1968-2017. Age-standardised incidence rates(ASR), overall survival, 5-/10-year relative survival ratio (RSR) were estimated. Joinpoint regression was used to evaluate quinquennial percent change (QPC) in incidence.

Results: We identified 2557 individuals diagnosed with MPN including 1031 chronic myeloid leukaemia (CML), 424 polycythaemia vera (PV), 389 essential thrombocythaemia (ET), 134 primary myelofibrosis (PMF) and 579 MPN unclassifiable (MPN-U). The overall respective ASRs per 100,000 for CML, PV, ET, PMF and MPN-U were 1.24, 1.15, 1.07, 0.43, and 0.80 in 2013-2017. Males had higher ASR than females in all MPNs. A gradual rise in incidence trends of CML was observed between 1968 and 2017 (QPC 2.1%, 95% CI -0.9, 5.3). The overall incidence trends of non-CML MPNs including PV (QPC 62.9%, 95% CI 19.3, 122.6), ET (QPC 54.2%, 95% CI 23.5, 92.3) and PMF (QPC 103.5%, 95% CI 19.1, 247.6) increased sharply during 1993-2017. Survival was lower in MPNs compared with expected survival in general population: 5-year RSRs were 0.82 (95% CI 0.78, 0.86), 0.96 (95% CI 0.91, 1.01), 0.96 (95% CI 0.92, 1.01), 0.53 (95% CI 0.43, 0.65), and 0.74 (95% CI 0.68, 0.80) for CML, PV, ET, PMF and MPN-U respectively.

Conclusion: CML incidence has increased marginally, whereas non-CML MPNs incidences have sharply increased. MPN patients have a lower relative survival compared to the general population, and patients with PV and ET have the most favourable relative survival. Median survival for CML patients has increased dramatically over the last 50 years.

Keywords: Incidence; Leukaemia, Myelogenous, Chronic, BCR-ABL positive; Myeloproliferative disorders; Polycythaemia vera; Primary myelofibrosis; Survival rate; Thrombocythaemia, essential.