Results of a policy of surveillance alone after surgical management of pediatric low-grade gliomas

Purpose: To document the incidence of tumor progression in pediatric patien ts with low-grade gliomas (LGGs), with particular emphasis on those patient s who did not receive postoperative chemotherapy or radiotherapy (RT). Methods and Materials: A database of 128 patients with histologically confi rmed LGGs (World Health Organization Grade I-II), age less than or equal to 18 years, who had been referred to the London Regional Cancer Center and D alhousie University between 1979 and 1995, was compiled. Results: The median follow-up for the 128 patients was 7.3 years. Of the 12 8 patients, 63 were male and 65 female. The median age was 7.0 years (range 0-18). Twenty-five patients underwent gross complete resection, 63 subtota l resection, and 40 patients biopsy. Ninety-one percent (n = 117) of the tu mors were astrocytomas, of which 22 were pilocytic, 3 were oligodendrogliom as, 7 were mixed gliomas, and 1 was a ganglioglioma. Of the 103 subtotally resected patients, 48 received postoperative RT (median dose 59 Gy in 25 fr actions) and 10 patients were irradiated at the time of tumor progression. The 5-year overall survival was 86%, cause-specific survival 88%, and 5-yea r progression-free survival 79%. The results of the univariate analysis of the overall survival by the Wilcoxon model were statistically significant f or Karnofsky performance status (p = 0.03), RT timing (i.e., postoperative vs. deferred; p = 0.05), and tumor location (p = 0.02). The analysis of pro gression-free survival confirmed the statistical significance of the extent of surgical resection (i.e., complete vs. subtotal resection; p = 0.02). N one of the patients who underwent gross complete resections received postop erative RT and none developed tumor recurrence. Of the 103 patients who had subtotal resections, 33 had progression, with a median postprogression sur vival of 39 months. The rate of tumor progression among the subtotally rese cted LGG patients who did not receive immediate postoperative RT was 42%. T he timing of RT and tumor location lost statistical significance for overal l survival when the completely resected patients were excluded from the ana lysis. Conclusions: The extent of surgical resection was prognostically significan t for progression-free survival but lost significance as a prognostic facto r once the complete resection patients were excluded from the analysis. At a median survival of 7.3 years, 42% of the subtotally resected LGG patients who did not receive immediate postoperative RT had tumor progression. No s tatistically significant difference in survival was seen between the postop erative and deferred RT groups, even though the postoperative RT group was a group with poorer prognostic features (bulky residual tumor postoperative ly, Karnofsky performance status < 70, and nonhemispheric, noncerebellar tu mors), indicating that RT may be beneficial for this particular subset of p atients. (C) 2001 Elsevier Science Inc.