Survival of patients with chronic myeloproliferative neoplasms and new primary cancers: a population-based cohort study

Background Patients with chronic myeloproliferative neoplasms are at increased risk of new solid or haematological cancers, but how prognosis is affected in patients with preceding myeloproliferative neoplasms is unclear. Methods We used data from population-based medical databases in Denmark from 1980 to 2011 to compare survival between cancer patients with and without a preceding diagnosis of myeloproliferative neoplasm, matched for age, sex, year of diagnosis, and type of cancer. We assessed outcomes by cancer stage and comorbidities. Findings Data were available for 1246 patients with a history of myeloproliferative neoplasms and we matched 5155 patients without a history of myeloproliferative neoplasm for comparison. Among patients with new localised solid cancers, 5-year survival was 49.8% (95% CI 39.1-59.6) for patients with preceding essential thrombocythaemia, 47.9% (42.1-53.4) for those with preceding polycythaemia vera, and 48.0% (34.1-60.7) for those with preceding chronic myeloid leukaemia. The values were 72.4% (68.4-76.0), 63.9% (61.5-66.2), and 74.3% (68.2-79.4), respectively, in matched patients without preceding myeloproliferative neoplasms. The risk of death among patients with a solid tumour and preceding myeloproliferative neoplasm was 1.21-2.28 times higher than in patients without myeloproliferative neoplasms. Excess mortality risk was observed irrespective of whether new cancers were diagnosed within 5 years or 5 years or more after myeloproliferative neoplasm. Interpretation Preceding myeloproliferative neoplasm is a predictor for poor outlook in patients who develop new primary cancers.