Adult pineoblastoma: A prospective study and twelve-year experience from three tertiary care cancer institutes of India depicting the effect of various independent parameters and therapeutic strategy on progression and survival in this extremely rare malignancy.

Background: Pineoblastomas are highly aggressive malignant grade-IV tumors of embryonal origin with poor prognosis, accounting for < 0.1% of all brain tumors, affecting mainly the pediatric and adolescent cases but extremely rare in adults with an incidence of 0.1%-<1%. With scarce Indian and world data involving adult patients due to its rarity and lack of large prospective cohorts, this study was undertaken to determine survival outcomes in adult cases undergoing surgery, postoperative radiation therapy, and chemotherapy in terms of clinical response, prognosis, and disease progression.

Methods: Intake, treatment, and follow-up of patients were done from July 2009 to July 2021. A total of 1085 cases of primary brain tumors comprising malignant and benign adult and pediatric patients were registered over the study period. Adult pineoblastomas constituted 10/1085 (0.9%) cases of all primary brain tumors. All eligible patients underwent surgery, postoperative radiation therapy with concurrent chemotherapy, followed by adjuvant chemotherapy. Univariate Cox regression analysis was used to identify possible prognostic factors. Kaplan-Meier survival analysis was performed to estimate survival.

Results: The median disease-free survival was 63 months, and the median overall survival was 83 months. Poor performance status (P = 0.043), greater presenting symptoms (P = 0.041), and presence of residual disease (P = 0.000) were identified as independent predictors of reduced disease-free survival, without affecting overall survival.

Conclusion: We undertook this study keeping the dose of postoperative radiation therapy and chemotherapy regimens constant for all patients irrespective of surgical status to maintain uniformity in the survival quotient. Despite the limitations, this study may represent the largest analysis of adult pineoblastomas reported in Indian literature to date.