Treatment of neuroectodermal brain tumors

Abstract

Prospective clinical trials support the view that malignant neuroectodermal tumors should be treated vigorously using a multimodal approach that includes surgical resection, high-dose radiation therapy, and prolonged maintenance chemotherapy. Less malignant astrocytomas and oligodendrogliomas should be treated by resection and irradiation. Laboratory research on neuroectodermal tumors has advanced rapidly, providing new data on tumor cell biology and the pharmacology of chemotherapy that directly influence the therapeutic options.

Prognostic value of cytogenetic analysis in human cerebral astrocytomas

“…The survival time of the cytogenetics study group patients with grade 4 tumor, however, was nearly identical to that of the clinical trial patients with grade 4 tumor; the median durations of survival were 294 days (42 weeks) and 292 days, respectively. These findings are similar to the values reported in comparable series [28]. Therefore, we consider the patients in the newly diagnosed group in the cytogenetics study who had high-grade tumor to be representative of the population of patients with newly diagnosed high-grade astrocytomas entered into clinical trials.…”

“…However, there is precedent on the value of chromosome clonality as a prognostic indicator in other tumor systems [S, 7). We want to emphasize that differences in therapy can alter outcome in patients with astrocytomas [28,29). The prognostic value of cytogenetic clonality may be less significant if advances in tumor therapy occur.…”

Analysis of Prognostic and Survival Factors Related to Treatment of Low-Grade Astrocytomas in Adults

“…Although it seems logical that more extensive surgery would lead to worse postoperative function, some studies indicate that more complete resection in low-grade gliomas produce a better postoperative performance status [1, 36]. Reduction in the tumor bulk is important in allowing adjuvant therapy to be more effective [1, 37], which may have an important impact on the survival statistics.…”

Indications for Surgery in the Management of Gliomas

“…The aim of cytoreduction is not to cure the patient but to achieve an essential first step in a multimodality treatment by removing as many neoplastic cells as possible. The often-quoted paradigm in cancer surgery adjusted to brain tumors (Levin 1976, Shapiro 1982) is as follows: given an initial tumor burden of 5 x 1010 cells (50 g), a subtotal or "total" surgical resection might remove 90% of the tumor and leave between 5 x 10 9 and I x 10 9 cells. Radiotherapy (RT) might kill two logs and chemotherapy (ChT) again two logs of cells leaving 1 x 10 5 cells to be killed by the body's immune mechanisms.…”