Treatment results of adults and children with medulloblastoma NCI, Cairo University experience.

PURPOSE

To evaluate treatment outcome and prognostic factors of adults and pediatric medulloblastoma patients treated by adjuvant postoperative craniospinal irradiation (CSI) and chemotherapy.

PATIENTS AND METHODS

Between 1997 and 2004, 67 patients were treated in the National cancer Institute- Cairo University; 51 pediatric patients with a median age of 7 years and 16 adult patients with a median age of 25 years. According to the Chang staging system; 50%-35% , 37.5%-47% and 12.5%-18% had T2, T3 and T4 tumors of adults and pediatric patient's population respectively. M1, M2 and M4 were reported in 16% , 3% and in 1.5% respectively. All patients underwent primary surgical resection; near total resection in 25% , Subtotal resection in 61% ; with tumor residual < 1.5cm(2) in 49% compared to 51% with > 1.5cm(2) residual tumor and 14% , had biopsy only. All patients were treated by craniospinal radiotherapy (RT); with a median dose of 34Gy to the whole brain, 54Gy to the posterior fossa and 32Gy to the spinal axis. The median interval between surgery and RT was 45 days and 38 days for the pediatric and adult groups respectively. The median duration of RT was 54 days and 52 days for pediatric and adult patients respectively. Thirty four pediatric patients (67% ) received concomitant chemotherapy, while 61% received adjuvant (postoperative) chemotherapy and 57% received sequential chemotherapy. Only 33% of patients did not receive chemotherapy. The median follow-up was 49 months for the whole group of patients (range 11-121).

RESULTS

For the pediatric and adult patients, the 5- and 7-year overall and disease-free survival rates were 89% & 78% Vs. 84% & 56% and 80% & 68% Vs. 79% & 52% respectively. Fourteen patients (21% ) relapsed (10 pediatric and 4 adults) at a median time of 11 months vs. 23 months and a median follow-up period of 8 and 12 months respectively; Neuro-axis was the most common site of relapse (11 patients). Ninety percent (9/10) of the pediatric relapses were of the high risk group (8 received no chemotherapy) and took place within 2 years; similarly all adult relapses were of the high risk group; three relapses took place after 2 years. In univariate analysis, T stages, M stages, extent of surgery, CSF seedling and risk category were significant prognostic factors for disease free survival for the pediatric age group. At 5 years, 87% , 87% , 78% , 85% and 85% of T2, M0, near total resection, negative CSF seedling and low risk patients were estimated to be disease-free respectively, compared to none of the T4, M +, biopsy only, positive CSF seedling patients and only 41% of the high risk patients achieved 5 years without recurrence (p=0.001, <0.001, <0.001, <0.001, <0.001). Patients who did not receive chemotherapy had a 69% 5-year DFS Vs. 76% (p=0.286). For adult patients; only the risk category was a significant prognostic factor with 5-year disease-free survival rate of 100% Vs. 40% for low and high risk respectively (p=0.03). On multivaiate analysis only the risk category and the T-stage were significant prognostic factors for disease free survival for the pediatric age group (p=0.042 and 0.031).

CONCLUSION

Survival rates of medulloblastoma pediatric patients were better than the adult ones. Neuro-axis relapse was the most common site of relapse for pediatric patients. Late relapses, lateral tumor location and shorter median follow up were noted in adult patients. Advanced tumor stage, metastases at presentation, limited tumor resection were powerful prognostic factors among the pediatric patients. In addition, high risk category was shown to be a prognostic factor for both pediatric and adult patients.