Incidence, prognostic factors, and survival outcomes in patients with blastic plasmacytoid dendritic cell neoplasm: A retrospective study in the Surveillance, Epidemiology, and End Results database.

There are few large-scale epidemiological and prognostic studies on blastic plasmacytoid dendritic cell neoplasm (BPDCN) due to its rarity. We used the Surveillance, Epidemiology, and End Results database to investigate the incidence, clinical characteristics, prognostic factors, and survival trends of BPDCN. The age-adjusted incidence of BPDCN had a bimodal pattern with peaks in those under 20 and 60 years and older. Of 697 patients, the median age at diagnosis was 31 years. The most common primary sites were lymph nodes (59.4%), followed by bone marrow (17.1%) and skin (11.6%). Extranodal involvement (59.7%) was more common in patients aged 60 years and older, while lymph node involvement was predominant in other age groups. The 1-year, 3-year, and 5-year overall survival (OS) rates were 90.7%, 83.7%, and 82.3% in patients aged under 20, but dropped to 53.1%, 27.7%, and 20.0% in patients aged 60 and older. Multivariate Cox regression analysis revealed that age, sex, and first malignancy were independent prognostic factors for OS. Based on this regression model, a nomogram was built with high discrimination and calibration. The incidence, clinical characteristics, and prognosis of BPDCN patients vary by age group. Moreover, using the nomogram to predict OS can help guide individualized evaluations and clinical decisions.