Primary central nervous system lymphoma

Abstract

Primary CNS lymphomas (PCNSL) represent a subgroup of malignancies with specific characteristics, aggressive course, and unsatisfactory outcome in contrast with other lymphomas comparable for tumour burden and/or histological type. Despite a high chemo- and radiosensitivity, remissions are frequently shortlasting, mainly because the blood brain-barrier limits the access of many drugs to the CNS. Moreover, survivor patients are at high risk of developing severe treatment-related toxicity, mainly disabling neurotoxicity, raising the question of how to balance therapy intensification with side-effects control. Although the prognosis remains poor, it has significantly improved over the past two decades as a result of better treatment strategies with a curative aim. Surgery has no impact on survival, and is reserved to diagnosis by stereotactic biopsy. Actual front-line therapy consists of high-dose methotrexate-based poly-chemotherapy. The optimal drugs combination has not yet been identified even if there is a suggestion for a synergistic role for the adjunction of cytarabine, thiotepa, and rituximab. Radiotherapy retains an important role as salvage therapy in refractory/relapsing patients, while its use is more debated in the setting of response consolidation in patients who achieve a complete remission after induction chemotherapy. High-dose chemotherapy supported by autologous stem-cell transplantation is increasingly used as an effective method aimed to control microscopic disease, and the pros and contras of this approach are outlined.

Keywords: Cerebrospinal fluid; Cytarabine; Methotrexate; PCNSL; Radiotherapy; Rituximab; Thiotepa.