Preoperative history and postoperative survival of supratentorial low-grade astrocytomas.
The preoperative history and postoperative course of histologically verified 348 low-grade and 383 anaplastic astrocytomas have been reviewed. In 71.2 and 48.0% of patients epilepsy was the initial symptom of a suspected astrocytoma, and the history was longer than 3 years in 28.1 and 19.5% of cases, respectively. Before the advent of CT, angiography was performed because of a suspected tumour 2-9 years before surgery in 34 cases. The second angiography years later demonstrated the tumour which in 18 cases at surgery proved to be low-grade astrocytoma or anaplastic astrocytoma in 16 cases. During the last 10 years CT or MRI demonstrated a low-density lesion in 21 patients years before surgery. Operation was postponed for different reasons. Ten tumours appeared at 'delayed' surgery as low-grade, but 11 as anaplastic astrocytoma. In the same period 29 further patients were operated on after a history of seizures, longer than 3 years. Histology showed anaplastic astrocytoma in 10 cases also. Malignant transformation occurred nearly in half of the patients during the observation period. This strongly suggests that dedifferentiation is a spontaneous process, an intrinsic feature of astrocytomas and does not depend on any kind of external stimulus. Another 51 patients' surgery was performed following a shorter (1-24 months) history of epilepsy. The 5-year survival rate was 44 and 39.5% Median survival times (53.5 and 51 months) did not show a significant difference between the two groups, but the total survival, including second survivals after reoperation displayed a significant difference (57.5 vs 67.5 months) in favour of patients with a shorter history of seizures. These experiences confirm the difficulties in decision of the time of surgery. Considering the frequent malignant transformation among patients with a long history of seizures, followed by a relatively shorter survival, it may be supposed that an early radical removal in suitable cases might prevent the late dedifferentiation and recurrence.
Afra
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D
National Institute of Neurosurgery, Budapest, Hungary.
Osztie
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E
Sipos
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L
Vitanovics
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D
D000293:Adolescent; D000328:Adult; D001254:Astrocytoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D004827:Epilepsy / Q000601:surgery; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care / Q000379:methods; D011300:Preoperative Care / Q000379:methods; D012189:Retrospective Studies; D015173:Supratentorial Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome