Current treatment of low grade astrocytoma: a review

Through a comprehensive review of the current literature, the present article investigates several aspects of low grade astrocytomas (LGA), including prognostic factors, treatment strategies and follow-up regimes. LGA are in general relatively slow-growing primary brain tumours, but they have a very heterogeneous clinical behaviour. Several factors affect prognosis, and these include age, histological subtype, and Karnofsky Performance Score (KPS) prior to surgery. Furthermore, a number of different molecular genetic alterations have been shown to affect both the prognosis as well as the course of disease. The current literature seems to support the idea that treatment with radical tumour resection, where possible, yields better long term outcome for patients with LGA. However, adjuvant therapy is often necessary. Administering early postoperative radiotherapy to patients with partially resected LGA yields a longer period of progression-free survival, whereas patients with radically resected tumours should receive radiotherapy at the time of progression. Regarding chemotherapy, we found evidence to suggest that patients respond to both temozolomide (TMZ) and the combination of procarbazine, lomustine and vincristine (PCV). However, the response rates in patients receiving PCV seem superior to those of patients receiving TMZ. In follow-up PET scans, the tracers (18)F-FDG and MET provide high sensitivities for detection of new suspicious lesions and these tracers are furthermore effective in discriminating between tumour progression and radiation necrosis. The research into biomarkers is currently limited with regards to their applications in LGA diagnostics, and therefore further studies including larger patient populations are needed.