Characteristics and natural history of primary vitreoretinal lymphoma (PVL) compared to the primary lymphoma of the CNS (PCNSL)

Abstract

Aim: Primary vitreoretinal lymphoma (PVL) is considered to be a subtype of primary CNS lymphoma and they often receive systemic treatment (Tx) based on PCNSL protocols instead of local Tx (intraocular methotrexate or local irradiation). In this work, we aimed to compare characteristics and natural history of these 2 lymphoma subtypes. Methods: Patients diagnosed and treated in General University Hospital, Prague, for PVL or PCNSL were compared according to their basal characteristics, prognostic factors, overall and progression-free survival (OS). Statistics were performed with chi-square, Mann-Whitney and log-rank tests. Results are given as medians. Results: Ten patients with PVL and 59 patients with PCNSL were diagnosed and treated in Charles University General Hospital, Prague from 2002 to 2016. PVL patients were diagnosed by cytology and FACS, while all PCNSL patients had brain biopsy. All PCNSL patients had ophthalmological examination. PVL and PCNSL patients were of similar age (57 v. 65 years, p = NS) and sex distribution. Five patients with PCNSL had intravitreal involvement (8%), 3 of them presented initially with visual impairment. PVL patients had better performance status (Karnofsky, 100 v. 60%, p 0.00006), otherwise the pretreatment characteristics were similar. Six patients with PVL received systemic Tx in comparison to all PCNSL patients (p = 0.002). Six and 22 patients, respectively, received rituximab in first-line treatment (p = NS). Median follow-up for living patients was 57 (PVL) and 69 months (PCNSL, p = NS). Patients with PVL had better PFS (39.9 v. 18.6 months, p = 0.04) and OS (not reached v. 32.8 months, p = 0.006). The only negative prognostic factor identified for PFS and OS in PCNSL patient was age over 50 years, while no prognostic factor was found in PVL patients. However, patients with PVL over 50 years still had better PFS and OS than corresponding PCNSL patients (39.9 v. 12.7 months, p = 0.04, and NR v. 23.9 months, p = 0.002). Patients with PVL who received only local Tx had similar prognosis than patient treated systemically. Rituximab did not improve outcome in either group of patients. Conclusion: Although PVL and PCNSL are closely related diseases, in our institution, patients with PVL had better prognosis than PCNSL patients. This difference was not explained by pretreatment factors. Although in a small number of pts, it seems that first-line local Tx for PVL could give the same results as systemic Tx. Keywords: extranodal lymphomas; primary CNS lymphoma (PCNSL)