Low-grade astrocytomas: prognosis factors and elements of management.

Background: The literature provides information concerning prognosis of low-grade astrocytomas, but the series are quite heterogeneous in terms of clinical material, neuropathological evaluation, and statistical methods of analysis. Therapeutical indications are poorly defined. The last World Health Organization (WHO) histological classification provided a very precise definition of low-grade gliomas.

Methods: Taking into account a recent study of our own and literature data, management guidelines of these tumors were proposed.

Results: Grade I (pilocytic and subependymal giant cell astrocytomas) are surgically curable lesions. No adjuvant treatment is mandatory. Management of grade II astrocytomas is less clear-cut. Conservative management is probably possible in young patients without functional threat. The role of surgery on duration of survival has been properly established in very few series and was negative in many others. The role of radiotherapy has been demonstrated in a few subgroups of patients. In our study of ordinary astrocytomas, considering decades of age at diagnosis, survival curve analysis established three prognostic classes of age (before 50, between 50 and 60, and after 60 years of age). Based on our results and on recently published data, a branch decisional approach was proposed for management of grade II astrocytomas. Other grade II gliomas exhibit more favorable prognoses but could be managed in the same manner.

Conclusions: Ordinary grade II astrocytomas constitute a paradigm of difficult differential management. Further pertinent information on these tumors could come from the field of tumor biology, or be provided by very large and homogeneous groups of patients.