Survival and prognostic factors in a series of adults with medulloblastomas

Abstract

Object In this article, the authors report their experience in the management of adult patients with medulloblastoma at their institution to identify prognostic factors important for survival and disease control. Methods Between 1977 and 2005, 27 patients who were ≥ 16 years old and had medulloblastoma were treated consecutively. There were 16 women and 11 men with a median age of 21 years (range 16–54 years). Gross-total resection was performed in 21 patients, subtotal (≥ 90%) in 2, incomplete in 1, and biopsy in 3 patients. Six patients had the desmoplastic variant, and 21 patients presented with classic medulloblastoma. Staging according to the Chang classification showed 4 patients with tumors invading the brainstem (2 with Stage T3b and 2 with Stage T4), 3 patients with metastases (2 with Stage M2 and 1 with Stage M3), and 1 patient in whom the stage was unknown (Stage MX) who died 10 days postoperatively. Twenty patients were assigned to the standard-risk group and 7 to the high-risk group. All patients except the one whose status was classified as Stage MX underwent craniospinal radiotherapy at our institution. Seven patients received chemotherapy before radiotherapy. Results The 5- and 10-year overall survival rates for the present study were 81 and 62%, respectively. The median overall survival time was 17.7 years. The 5- and 10-year event-free survival rates were 72 and 57%, respectively. The median event-free survival time was 17.9 years. Univariate analysis showed that survival was significantly correlated with sex (women had a better prognosis than men) and M stage (patients without metastases had a better outcome). Patient age, duration of symptoms, Karnofsky Performance Scale score at presentation, hydrocephalus, tumor location, brainstem invasion, extent of resection, histological subtype, preradiotherapy chemotherapy, risk group, and period of presentation were not significant variables. Multivariate analysis identified sex and M stage as well as the period of presentation as independent prognostic factors for overall and event-free survival times. Eleven patients suffered tumor recurrence within a median time of 4.2 years. The posterior fossa was not the most common site of recurrence, and delayed recurrence was not rare. All patients in whom the tumor recurred have died despite aggressive treatments. The median survival time after diagnosis of recurrence was 2.5 years. Questionnaires on quality of life and cognition showed high scores in favor of limited negative effects in the perception of mental and physical health after treatment. The authors observed 1 supposed second malignancy (thyroid carcinoma) and no evidence of pituitary dysfunction. Conclusions Long-term survival is possible in adults treated for medulloblastoma. Although rare, metastasis seeding at presentation is a poor prognostic factor. The possibility of delayed recurrence necessitates close follow-up of all patients. Tumor recurrences should be treated with aggressive therapies as some patients may have sustained response. Adjuvant chemotherapy should be given to high-risk patients, but its role in reducing recurrences, particularly distant ones, remains unclear in the standard-risk group.