Primary central nervous system lymphoma in the United States, 1975–2017

BACKGROUND: Primary central nervous system lymphoma (PCNSL) has received more attention because of an inferior prognosis. Less is known about the incidence rate, histological type, and survival rate of PCNSL, especially in the 2010s. METHODS: Data of PCNSL from the Surveillance, Epidemiology, and End Results (SEER) registry database (SEER 9 registries and SEER 18 registries) were used. Incidence was estimated by age, gender, race, site, and histological type. Trends were analyzed using joinpoint regression and described as annual percent change (APC) and average annual percent change (AAPC). Five-year overall survival estimates were compared using log-rank tests. RESULTS: Most PCNSL occurred in the brain, followed by the spinal cord. The most frequent histological type of PCNSL was diffuse large B-cell lymphoma, followed by marginal zone lymphoma. Incidence rate increased from 0.1/100,000 to 0.5/100,000 with an AAPC of 5.3% from 1975 to 2017. Incidence rates varied greatly between the younger and older age population. The 5-year overall survival rates in SEER 9 registries and SEER 18 registries were 30.5% and 37.4%, respectively. Even though the 5-year overall survival rate significantly increased from 27.9% for the 1975–1979 time period to 44.8% for the 2010–2017 time period, survival benefit could not be expected for patients ⩾60 years. The 5-year survival rate for elderly patients was about 30% in the 2010s. CONCLUSION: With aging, the incidence of PCNSL in the elderly is increased. Over the past decade, no advances have been made in the treatment of elderly PCNSL. Prospective trials with PCNSL are warranted to improve the survival of elderly patients.