US death rates from myeloproliferative neoplasms, and implications for cancer surveillance.

Myeloproliferative neoplasms (MPN) may contribute to death from other causes due to complications and sequelae of MPN or its treatment. The present study found that the US death rate for MPN (polycythemia vera, essential thrombocythemia/thrombocytosis, and "chronic myeloproliferative disease") in 2005-2006 was twice as high using all causes of the death on the death certificate (6,488 deaths, age-standardized rate 1.06 per 100,000 per year) vs only the underlying cause (3,303 deaths, age-standardized rate 0.54 per 100,000 per year). This finding was consistent by age, gender, race (African American/black and white) and Hispanic ethnicity. Thus, surveillance of trends in MPN-related mortality rates in the population needs to take into account all causes of death on the death certificate, because MPN contributes to death from other causes such as thrombosis. MPN is a major cause of splanchnic vein thrombosis (SVT), and under-ascertainment of MPN-related deaths was suggested by the small proportion (3%) of all 848 US deaths in 2005-2006 with SVT coded as any cause of death that also had MPN coded. Increased clinical testing of peripheral blood for specific acquired genetic mutations, known since 2005 as being common in certain MPN and also in SVT, could lead to increased numbers of deaths certified as MPN-related and also incident cases of MPN reported to central cancer registries.