Treatment outcome and patterns of failure in patients of pinealoblastoma: review of literature and clinical experience from a regional cancer centre in north India.

Abstract

Pinealoblastoma is a highly malignant embryonal tumour of the pineal region affecting children and young adults. We herein intend to report the clinical features and treatment outcome of patients of pinealoblastoma treated at our institute. Clinical data was collected by retrospective chart review from 2003-2012. Histopathology slides were reviewed, and relevant immunohistochemistry stains were done. Overall survival (OS) and recurrence-free survival (RFS) were analysed by Kaplan-Meier product-limit method. Univariate and multivariate analyses of prognostic factors were done by log rank test and Cox proportional hazard regression model, respectively. Seventeen patients met the study criterion (male:female = 11:6). Median age at presentation was 14 years (range 4-47 years). Surgical resection was gross total in 6 (35.29%), near-total in 2 (11.76%), sub-total in 2 (11.76%), and limited to biopsy in 7 (41.18 %) patients. At presentation, 4 patients had leptomeningeal dissemination. Radiation therapy was delivered in all patients-craniospinal irradiation in 15 (88.24%), whole brain irradiation in 1 (5.88%), and whole ventricular irradiation followed by boost in 1 (5.88%) patient. Systemic chemotherapy (median 6 cycles) was given in 14 (82.35%) patients. The most common regimen was a combination of carboplatin and etoposide, used in 10 (58.82%) patients. After a median follow-up of 30.3 months (mean 32.01 months), death and disease recurrences were noted in 3 (17.65%) and 7 (41.18%) patients. Amongst the patients with recurrent disease, 4 had spinal drop metastases and 3 had local recurrence along with spinal drop metastases. Median OS was not reached, and estimated median RFS was noted to be 5.49 years. The actuarial rates of OS and RFS at 2 years were 85.6 and 73.1%, respectively. On univariate analysis, age more than 8 years (P = 0.0071) and M0 stage (P = 0.0483) were significant predictors of improved RFS. Age retained significance on multivariate analysis of RFS (P = 0.02932). Maximal safe resection followed by craniospinal irradiation and systemic chemotherapy with 6 cycles of carboplatin-etoposide regimen is a reasonable treatment strategy in patients of pinealoblastoma more than 8 years of age in a developing nation. However, the same strategy is less effective in younger children and innovative study designs of intensification of post-operative treatment must be explored in this age group.