Systemic Anaplastic Lymphoma Kinase-positive Anaplastic Large Cell Lymphoma: A Population-based Analysis of Incidence and Survival.

INTRODUCTION: Systemic ALK-positive anaplastic large cell lymphoma (ALK-positive ALCL) is a T-cell lymphoma. Owing to its rarity, variations in incidence and survival at the population level are not clearly known.

MATERIALS AND METHODS: Using the Surveillance Epidemiology and End Results database (SEER 18), we selected patients aged ≥ 20 years with ALK-positive ALCL, diagnosed between 2001 and 2013. Incidence rate, overall survival (OS), and its determinants were analyzed with a significance level of P < .05.

RESULTS: We identified 1604 patients with a median age of 54 years. The disease incidence increased significantly with advancing age, with higher incidence in Blacks and lower incidence in American Indians and Asian/Pacific Islanders as compared with Whites. The 5-year OS significantly declined as the age advanced (age 20-40 years, 68.7%; age 41-60 years, 53.8%; age 61-80 years, 28.9%; age > 80 years, 15.2%; P < .01) and varied with race (Whites, 49.7% vs. Blacks, 37.7% vs. Asian/Pacific Islander, 42.8% vs. American Indian, 35.8%; P = .03). On multivariate analysis, treatment with radiation (hazard ratio [HR], 0.72; 95% confidence interval [95% CI], 0.59-0.87; P < .01) and year of diagnosis from 2009 through 2013 (HR, 0.77; 95% CI, 0.65-0.93; P < .01) were associated with lower mortality. Advanced age, Black race (HR, 1.37; 95% CI, 1.14-1.65; P < .01), and advanced disease stage (HR, 1.74; 95% CI, 1.51-2.02; P < .01) were associated with higher mortality.

CONCLUSION: Incidence and survival of ALK-positive ALCL varies significantly with patients' demographic characteristics as identified in our study. Treatment strategies need to be tailored accordingly to address these variations and ensure uniform access to care.