Epidemiology, outcomes, and prognostic factors of orbital lymphoma in the United States.

PURPOSE: We performed an epidemiological study of orbital lymphoma in the United States to determine how histological subtypes confer differing prognosis, and understand other factors associated with survival.

METHODS: All patients in the Surveillance, Epidemiology and End Results database diagnosed with a histologically confirmed orbital lymphoma between 1973 and 2014 were included. Exclusion criteria included diagnosis at autopsy and the presence of other malignancies. Measures included patient demographic information, histological subtype and treatment modalities. Outcomes included overall and disease specific survival.

RESULTS: Of the 1504 cases identified, 702 were male (46.7%, mean age: 64.4 years, standard deviation [SD]: 15.3) and 802 were female (53.3%, mean age: 67.5 years, SD: 14.3). Mucosal associated lymphoid tissue (MALT) (49.5%) and diffuse large B cell lymphoma (DLBCL) (19.5%) were the two most common histologic subtypes. MALT lymphoma conferred the best prognosis (10-year cancer specific survival [CSS] 90.2%, 95% Confidence Interval [CI] 87.4% - 93.1%) and DLBCL conferred the worst prognosis (10-year CSS 68.6%, 95% CI 62.5% - 75.3%) (p < .001, log-rank test). Older age (Hazard Ratio [HR]: 3.71, 95% Confidence Interval [CI]: 2.94-4.66, p < .001), male sex (HR: 1.22, 95% CI: 1.039-1.441, p = .015), no radiation (HR: 1.72, 95% CI: 1.46-2.02, p < .001) and DLBCL histology were significant predictors of worse overall survival.

CONCLUSIONS: DLBCL histology confers the worst outcomes whereas MALT lymphoma confers the best outcome in orbital lymphoma. Age, gender, and radiation treatment also influence survival. These epidemiological results can be used clinically to communicate outcomes on the basis of patient characteristics and disease histology.