P05.60 Management of Adult Patients with Medulloblastoma at Skane University Hospital Between 1994 and 2017

We report our experience in the management of adult patients with medulloblastoma, exploring prognostic factors important for survival and disease control. Between 1994 and 2017, 23 consecutive patients with medulloblastoma and age ≥ 18 years old were treated. Sixteen were men and 7 women, median age at diagnosis was 26 years (range 18–62 years). Median follow-up time was 16 years (range 0, 3–24 years). Gross total resection (GTR) was performed in 12 patients, subtotal resection (STR) (≥ 1, 5 cm2 residual disease) in 10 patients and biopsy in 1 patient. Staging according to the Chang classification showed that 20 patients had T2, 1 patient T3a and 2 patients had unknown T stage. M staging showed 20 patients without metastases (M0) and 3 patients with seeding in the spinal subarachnoid space (M3). Twelve patients were assigned to the average-risk group (any T stage, GTR and M0) and 11 to the high-risk group (residual tumour and or metastases). All patients underwent surgery and postoperative craniospinal irradiation (CSI). Vincristine was given weekly concomitantly with CSI in 10 patients. Adjuvant chemotherapy was given to 16 patients. The 5- and 10-year overall survival (OS) rates for the present study were 76% (95% CI 53% -100 %) and 60% (95% CI 28 -92 %), respectively. The 5- and 10 years progression-free survival was 59% (95% CI 35 -82 %) and 47% (95% CI 21–72 %), respectively. Normal approximation confidence interval and Fisher′s exact test was used to analyse outcome. Ten years OS was significantly (p=0.0111) correlated with extent of resection (patients with GTR had a better outcome). Patient gender, age, hydrocephalus that required VP-shunt, tumour location, T-stage, M-stage, time interval between surgery and start of CSI, time interval between end of CSI and start of adjuvant chemotherapy, concomittant vinkristin and adjuvant chemotherapy did have overlapping confidence interval which strongly indicate differences in OS not being significant. Ten patients had tumour recurrence with a median time to recurrence of 15 months. Nine out of ten relapses occurred locally in the posterior fossa. Late recurrences were not rare, two patients relapsed more than 5 years after diagnosis. Generally, the results of salvage therapy for recurrent disease have been poor, with only one patient with long term survival after recurrence. At last follow up, three patients were fully recovered with no deterioration. Five patients suffered from cognitive impairment or substantial fatigue, three from pituitary insufficiency and one from hearing and vestibular dysfunction. Long-term survival is possible in adults treated for medulloblastoma. Late relapse is common and long-term follow-up is important. Our results confirm complete resection as important prognostic factor in this population based clinical patient sample.