Cognitive functioning and health-related quality of life in patients with newly diagnosed primary CNS lymphoma: a systematic review

Incidence of primary CNS lymphoma (PCNSL) is increasing, while prognosis is improving as treatments advance. However, declined cognitive functioning remains a major challenge in the treatment of PCNSL. This cognitive decline, in conjunction with other symptoms caused by the disease or its treatment, or both, can compromise health-related quality of life (HRQOL). The aim of this Review was to give a comprehensive overview on cognitive functioning and HRQOL for patients with PCNSL, including an evaluation of patient-related and treatment-related factors that can influence cognitive functioning and HRQOL. We reviewed the literature for studies on cognitive functioning and HRQOL in newly diagnosed adult patients with PCNSL using MEDLINE/PubMed, Embase, Web of Science, Scopus, Cochrane, PsycINFO, CINAHL EBSCO, and Google Scholar, up to Jan 4, 2018. Articles were selected using predetermined inclusion and exclusion criteria; 42 articles were eligible for inclusion. Findings show that the tumour itself has a great effect on cognitive functioning and HRQOL. Initially, induction chemotherapy results in improvement of cognition and HRQOL in most patients. In the long-term, the addition of whole-brain radiotherapy has a negative effect on cognitive functioning, but the magnitude of this effect is not always clinically relevant. HRQOL scores were worse compared with controls, and worse after combined chemotherapy and radiotherapy when compared with chemotherapy only, particularly in the long term. Therefore, combined chemotherapy and radiotherapy seems to have a negative effect on HRQOL and cognition in patients with PCNSL. Although prolonged progression-free survival is achieved with combined treatment, information on its effect on cognition and HRQOL should be included in clinical decision-making.