OS10.3 Primary therapy and survival in over 70-year-old patients with primary central nervous system lymphoma: a contemporary, nationwide, population-based study in the Netherlands

Abstract

Abstract BACKGROUND Elderly patients with primary central nervous system lymphoma (PCNSL) have a poor prognosis. In this contemporary, nationwide, population-based study, we assessed the contribution of primary therapy on overall survival (OS) among elderly PCNSL patients in the Netherlands. METHODS All patients aged ≥ 70 years with cytologically and/or histologically proven PCNSL diagnosed between 2014–2016 were selected from the nationwide Netherlands Cancer Registry. Univariable analysis of OS was performed with the log-rank test. Multivariable Cox regression was applied to assess factors associated with OS, with adjustment for age (71–74, 75–79 and ≥80 years), sex, prior malignancy, primary therapy (no therapy, radiotherapy [RT] only, chemotherapy [CT]), and rituximab treatment. RESULTS Overall, 109 patients were registered; 39%, 39%, and 22% were aged 71–74, 75–79 and ≥80 years, respectively. Most patients received CT (45%), followed by no therapy (33%) and RT only (22%). With increasing age, the application of CT decreased (60%, 43%, and 24%), and RT only increased (10%, 26%, 26%) in the three age groups. CT consisted of methotrexate (MTX)-based or MTX only regimens in 98%. In patients treated with CT, Rituximab was added in 31%. During follow-up, 89 patients (82%) died. Median OS was 5.3 months (95% confidence interval [CI], 3.3–7.8), no difference was observed in median OS across the three age groups (6.8, 4.4, and 4.6 months, respectively; P=0.348). However, in the groups no therapy, RT only, and CT, median OS (95% CI) was 1.3 (1.0–2.0), 6.5 (4.4–12.5), and 20.3 (8.6–41.4) months (P<0.001), respectively. Moreover, 2 year OS (95%CI) was 49% (34–62) in patients treated with chemotherapy compared with 17% (5–34) in patients treated with RT. Median OS (95% CI) was 20.3 (8.6–41.4) in recipients of MTX-based regimens and 5.0 (2.4-not reached) months in recipients MTX only (P=0.185). In multivariable analysis, treatment with CT or RT was the only factor associated with OS: age group and the addition of Rituximab were not associated with OS. CONCLUSION In this contemporary population-based study, OS remained poor among patients with PCNSL aged over 70 years, irrespective of age group. Clinical condition likely influenced therapy choices but in those judged fit enough to receive CT, almost 50% survived 2 years. Therefore, future prospective intervention studies are warranted to assess which group of elderly patients benefit from CT or less intensive approaches.