Childhood medulloblastoma in Britain 1971-77: analysis of treatment and survival.

In a population-based series of 368 children undergoing surgery for medulloblastoma, 304 (83%) survived to complete a course of radiotherapy. Among those patients who completed radiotherapy, the short-term survival rates were lower for young children (those aged under 5 years) than for older children, but by 6 years the survival rates were very similar (approximately 35%) for children in both age groups. Higher survival rates were obtained in the young children where total macroscopic excision of the tumour was achieved. For older children there was no difference in survival rates between those with total or partial excision, though the survival rate was lower for those whose surgery was limited to biopsy. In young children radiotherapy dose had no effect on survival rates. In older children, survival rates were appreciably higher where doses had been at least 45 Gy to the posterior fossa and 30 Gy to the spinal cord, and there were also fewer spinal cord metastases among those who received a higher spinal cord dose. Ninety (30%) of the 304 children also received chemotherapy as part of their initially planned treatment; a wide variety of protocols was used and no conclusions could be drawn as to the effects on survival rates.