Primary intracranial pure endodermal sinus tumor: a retrospective series of 6 cases in a single center and a systematic review of overall survival

Abstract Background: Primary intracranial pure endodermal sinus tumor (EST) is a rare malignant nongerminomatous germ cell tumor. There is still lack of knowledge about the treatment and prognosis. Methods: We studied 6 cases of primary intracranial pure EST patients in Beijing Tiantan Hospital from June 2009 to June 2015. A comprehensive literature search was performed on Pubmed’s electronic database using the search terms “primary intracranial endodermal sinus tumor”, “primary intracranial yolk sac tumor” and “malignant germ cell tumor”. Survival rates based on age, gender, tumor location, treatment, resection degree and metastatis were collected and analyzed. Results: Total resection was achieved in three patients and subtotal resection was achieved in three patients. Blood AFP level continuously decreased after tumor removal. In our case series, the longest survival time was 99 months; this patient received surgery + adjuvant therapy. Fifty-two cases were eligible and met the inclusion criteria for the review analysis. The majority of the population were in the young child to adolescent age and there is a male predominance in this study. In the Kaplan-Meier survival analysis, age, gender, tumor location and metastasis did not affect patients’ OS. Better OS was found in patients who had subtotal and gross total resection of the tumor. Patients who had surgery combined with adjuvant therapy showed better OS compared to those who just had surgery. Conclusion: Total resection of the tumor is necessary and EST is sensitive to adjuvant therapy.