Average survival after recurrence of a malignant astrocytoma is brief (4-5 months for Grade IV astrocytomas). All therapeutic options remain palliative and must take into account patient’s quality of life. The following treatment modalities should be considered:
- Radiation therapy. Since most patients have received radiation therapy, the role of re-irradiation is limited. Brachytherapy has been shown to be of limited benefit (1) and studies are ongoing evaluating stereotactic radiosurgery for recurrent small volume disease. The risk of radionecrosis remains high with either of these modalities.
- Surgery. Patients with limited recurrence in a resectable location with good performance status may benefit from re-resection.(2). This is especially true if the tumour has shown good response to initial therapy. Apart from possible survival benefits, potential benefits of re-resection include a)re-evaluation of pathology (especially tumour vs. radionecrosis), b)reduction in neurologic symptoms especially if due to mass effect, edema or hydrocephalus, c) obtaining a minimal residual tumour bulk for further systemic therapy.
- Systemic therapy. Patients who have not received prior chemotherapy should be considered for nitrosourea chemotherapy, especially if performance status remains high (KPS >50). Response rates vary from 30-50%(3) but are often short-lived. For patients who have previously received nitrosoureas, procarbazine has similar response rates and may be considered. Other potentially useful agents include carboplatin, etoposide, temozolomide or high dose tamoxifen but less data on these agents is available.
Finally, since treatment is less than ideal and responses are brief, these patients should be considered for experimental trials especially of novel anti-neoplastic agents.
References:
Bernstein M, Laperriere N, Glen J, et al. Brachytherapy for recurrent malignant astrocytoma. Int J Radiat Oncol Biol Phys 30:1213-1217, 1994.
Young B, Oldfield EH, Markesberg WR, et al. Re-operation for glioblastoma. J Neurosurg 55:917-921, 1981.
Wilson CB, Gutin PH, Boldrey EB, et al. Single agent chemotherapy of brain tumours: a 5-year review. Arch Neurol 33:739-744, 1976.
