Recent decline in the U.S. death rate from myeloproliferative neoplasms, 1999-2006.

BACKGROUND

Myeloproliferative neoplasms (MPNs) are classified as neoplasms of uncertain or unknown behavior in the International Classification of Diseases (ICD) Version 10 and can contribute to risk of death from complications (especially thrombosis).

METHODS

U.S age-standardized death rates using ICD-Version 10 codes relevant to classical MPN (i.e., polycythemia vera, essential thrombocythemia, and "chronic myeloproliferative disease") were examined for 1999-2006. The underlying cause of death and also all causes ("multiple causes" or "mentions") coded on death certificates were considered. Trends were assessed by using percentage change (PC) in rate between 1999 and 2006, and annual percentage change (APC) estimated from linear regression.

RESULTS

The decline in death rates was large for MPN, whether based only the underlying cause (PC=-19.7%, APC=-3.4%) or on the substantially higher rates based on any cause (PC=-24.1%, APC=-3.8%), and was consistent by gender and age group (<65 and 65+ years). For deaths with MPN coded as other than the underlying cause, cardiovascular diseases were the most common underlying cause and the ASR for these deaths declined substantially (PC=-40.0%).

CONCLUSIONS

Use of the underlying cause of death in surveillance will considerably underestimate MPN-related mortality rates in the population. Studies are needed on treatment in random samples of MPN patients from population-based cancer registries. Continued surveillance of MPN-related mortality rates in the population is needed in view of recent attempts (including the use of aspirin) to control cardiovascular complications of MPN.