Primary brain tumours in adults

Summary

Important advances have been made in the understanding and management of adult gliomas and primary CNS lymphomas—the two most common primary brain tumours. Progress in imaging has led to a better analysis of the nature and grade of these tumours. Findings from large phase 3 studies have yielded some standard treatments for gliomas, and have confirmed the prognostic value of specific molecular alterations. High-throughput methods that enable genome-wide analysis of tumours have improved the knowledge of tumour biology, which should lead to a better classification of gliomas and pave the way for so-called targeted therapy trials. Primary CNS lymphomas are a group of rare non-Hodgkin lymphomas. High-dose methotrexate-based regimens increase survival, but the standards of care and the place of whole-brain radiotherapy remain unclear, and are likely to depend on the age of the patient. The focus now is on the development of new polychemotherapy regimens to reduce or defer whole-brain radiotherapy and its delayed complications.

Introduction

There have been substantial advances in the understanding of the biology and clinical aspects (neuroimaging and multidisciplinary management) of primary malignant brain tumours in adults since our previous Lancet Seminar on the subject in 2003.¹ We focus on gliomas and primary CNS lymphomas, which are by far the most frequent primary brain tumours in adults (figure 1).² Meningiomas and pituitary adenomas are also frequent in adults, but are extraparenchymatous tumours and, because their treatments are mainly surgical or endocrinological, they fall outside the scope of this Seminar. We place particular emphasis on new findings that have the potential to affect practice, most of which are therapeutic advances and important trials.