AbstractObjectiveThe clinical characteristics and survival of patients with myeloproliferative neoplasms (MPNs) with secondary cancer were analyzed to explore the possible risk factors for secondary cancer in MPN patients.MethodsThe clinical characteristics of 1060 Chinese patients with MPN were retrospectively analyzed. The Kaplan–Meier method was used to analyze the survival. The Cox multivariate regression model was used to analyze the risk factors for developing secondary cancer in patients with MPNs.ResultsThe 1060 patients with MPN had a median follow‐up of 10 years (range 1–50) and a median age of 55 years (range 21–86), and 497 (45.2%) were male. The proportion of PV, ET, and PMF was 52.2%, 33.5%, and 14.3%, respectively. About 28.1% (298/1060) of 1060 MPN patients died. The median survival times of the PV, ET, and PMF groups were 20, 24, and 12 years, respectively (p< 0.0001). In age‐ and sex‐matched healthy Chinese patients, the standardized incidence ratio (SIR) value of developing secondary cancer in MPN patients was 6.41 (95% CI: 4.90–9.48). The median survival time was 14 years in the MPN with secondary cancer group. The Cox multivariate analysis showed that age ≥ 65 years (p< 0.0001, HR = 5.027, 95% CI [2.823, 8.952]), MF‐1 (p= 0.001, HR = 2.887, 95% CI [1.503, 5.545]) were risk factors for developing secondary cancer.ConclusionsThe survival of MPN patients with secondary cancer was significantly worse than that of patients without secondary cancer. Compared with normal subjects, MPN patients had a 6.41‐fold increased risk of developing secondary cancer, and age ≥ 65 years and MF‐1 were risk factors for developing secondary cancer in MPN patients.