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

We used the Surveillance, Epidemiology, and End Results database to study the incidence and survival of anaplastic lymphoma kinase-positive anaplastic large cell lymphoma. We found that the disease incidence varied significantly by age, gender, and race, whereas survival was influenced by age, race, stage, period of diagnosis, and radiotherapy. 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.