Tanja H.
AANS: No Added Benefit To Radiation Or Surgery With Adjuvant Chemotherapy For Glioblastomas
By Cameron Johnston
Special to DG News
TORONTO, ON -- April 25, 2001 -- A Korean study presented at the annual meeting of the American Association of Neurological Surgeons has suggested that adjuvant chemotherapy confers no added benefit on top of radiotherapy and surgery for patients with glioblastoma multiforme.
In most cancer centres, chemotherapy has long been considered part of the standard treatment modality for these patients. The fact that long-term results have been unimpressive, however, has caused many to question whether this adjuvant chemotherapy is a wise practice option.
"Despite recent advance in neuroimaging, neuroanesthesia and neurosurgical techniques, the prognosis for patients with surgery alone remains dismal," Drs. Jeong Hoon Kim and colleagues from the Asian medical school at the University of Ulsan, Seoul, South Korea said in their presentation.
"This reflects the infiltrative growth characteristics of glioblastomas which make resection impossible without causing further neurological damage to the patient. The need for further therapy after surgical resection prompted investigators to evaluate postoperative chemotherapeutic regimens. Several of these studies suggested a significant survival advantage for patients receiving post-operative radiation. In contrast to radiation however, the efficacy of post-operative chemotherapy has been more difficult to evaluate, and the value chemotherapy following standard post-op radiation remains controversial."
The investigators presented the results of a long-term study involving of 204 patients with glioblastoma multiforme who received one of three treatment regimens. One group (n=67) received 50-65 Gy of whole brain radiation in 25-30 fractions five days a week over six weeks, in addition to surgical resection. They also received varying chemotherapeutic regimens consisting of paclitaxel, tamoxifen, platinum and/or ACNU ((1-4-amino-2-methyl-5-pyrimidinyl)-methyl-3-(2-chloroethyl)-3-nitrosourea) for varying periods and in a variety of doses.
A second group (n=106) were treated with surgery and radiation alone, while a third group (n=31) were treated only with surgical resection.
The mean survival times for those receiving triple therapy was 15 months, for those receiving chemotherapy and radiation it was 11 months, and for those with surgery alone it was three months (p=0.0001)
One-year survival rates were 75.7 percent, 39.3 percent and 9.7 percent, respectively, among the three groups. Two-year survival was 25 percent, 15.4 percent and 6.5 percent, respectively. These measures were all highly statistically significant.
There were no differences in survival rates according to the chemotherapy regimen that was used, or when it as commenced. Karnofsky Performance Score (KPS) and age, however, were significant predictors.
Those who had KPS >90 had a survival rate of 100 percent at one year and of 57 percent at two years. Those whose KPS was >80 had a 67.2 percent survival rate at one year and zero percent survival at two years. Those whose KPS was <70 had a 2.3 percent survival rate at one year and zero percent at two years.
There was also a statistically significant correlation with the extent of the surgery and whether the patient had a gross total resection, a subtotal resection or a partial resection.
These results suggest that the addition of chemotherapy to radiation therapy does not affect overall survival in patients with glioblastoma multiforme, the researchers concluded.
Those patients who were most likely to benefit from the added chemotherapy were patients who already were at less risk of morbidity and mortality and were younger, had better Karnofsky scores, and has less residual tumor, they added.