We report here the first population-based incidence rates and prognosis of primary central nervous system lymphoma (PCNSL) in Finland.

Finnish Cancer Registry data by histological diagnosis and tumor location (2007–2017) for cases with diffuse large B-cell lymphoma.

During 2007–2017, 392 new cases of PCNSL were reported (195 males, 197 females). The average age-adjusted incidence was 0.68/100,000 person-years. Incidence for males was 0.74/100,000 and for females 0.63/100,000, respectively. The incidence was highest, 2.93/100,000, among people aged 75–79 years. Concerning all cases in 2007–2017 the 2-year age-adjusted relative survival rate was 33% and the corresponding 5-year survival rate was 26%. Among patients under the age of 70, the age-adjusted 5-year relative survival rate increased from 36% in 2007–2012 to 43% for 2013–2017. Among patients aged 70+ the corresponding survival rates were poor, 7 and 9%.

PCNSL incidence in Finland is among the highest reported in the world. The annual increase in incidence was 2.4%. The prognosis is still dismal, especially in elderly patients.