CHEMOTHERAPY FOR PILOCYTIC ASTROCYTOMAS

Background. Although pilocytic astrocytomas (PA) generally are conside red benign, a subset of patients with PA have disease progression desp ite standard treatment with surgery and radiation therapy. The authors report their experience with chemotherapy in this patient group. Meth ods. The authors treated 11 patients (4 males and 7 females; median ag e at diagnosis, 8 years) with pathologically confirmed PA with chemoth erapy. In eight patients, tumor progression or recurrence despite prio r surgery and radiation therapy led to chemotherapy treatment. In thre e children younger than 5 years, chemotherapy was given in lieu of rad iation therapy immediately after diagnosis (in one patient) or at the time of disease progression after surgery (in two patients). The autho rs used ten different chemotherapy regimens to treat the 11 patients. Results. Chemotherapy produced clinical and radiographic improvement ( R/R) in four (36%) patients, clinical stabilization and radiographic i mprovement (SD/R) in 1 (9%), clinical and radiographic stabilization ( SD/SD) in 3 (27%), and was associated with clinical and radiographic p rogression (PD/PD) in 3 (27%). Three of the five patients with radiogr aphic improvement had a greater than 75% reduction of maximal cross-se ctional tumor area. Hematologic toxicity resulted in dose reductions i n 43 of 110 (39%) total courses of chemotherapy. There were three hosp ital admissions for fever and neutropenia and one chemotherapy-related death. Conclusions. The authors conclude that chemotherapy may benefi t those with progressive inoperable PA. Chemotherapy may delay the nee d for radiation therapy in young patients with unresectable PA requiri ng treatment. PA may be a chemosensitive primary brain tumor.