Intraocular lymphoma in Korea: the Consortium for Improving Survival of Lymphoma (CISL) study

BACKGROUND: Intraocular lymphoma (IOL) is a rare malignant lymphoma that most closely resembles a diffuse large B-cell lymphoma, and it is a subtype of primary central nervous system lymphoma (PCNSL). IOL is located inside the eye in the retina, uvea, and/or optic nerve. We retrospectively analyzed IOL patient data to identify treatment patterns and survival rates in Korea. METHODS: Cytological confirmation for a diagnosis of IOL was performed for all patients. The clinical data collected from medical records included Ann Arbor stage, International Prognostic Index, performance status, date of diagnosis, treatment modality and response, date of relapse, and date of last follow-up. RESULTS: Twenty patients who were diagnosed with IOL, between December 2007 and June 2014 at multiple centers in Korea, were included in the analysis. Four patients were diagnosed with IOL alone, not involving the CNS. Two patients with isolated IOL later developed PCNSL. Nine patients developed CNS lesions before the onset of ocular lymphoma. Five patients had simultaneous onset in the eye and CNS. Twelve patients were treated by intravitreal injection of methotrexate for IOL. The median progression-free survival (PFS) for patients was 19.7 months (95% CI, 8.7-30.7 mo). The estimated 3-year overall survival (OS) for all patients was 75.1%. CONCLUSION: Treatment for IOL patients included radiotherapy and intraocular chemotherapy. IOL patients showed favorable PFS and OS. These patients would require long-term follow-up to identify relapse and adverse effects of radiotherapy or intraocular chemotherapy.