Primary intracranial alveolar soft part sarcomas: a report of seven cases and a pooled analysis of individual patient data.

Objective: Primary intracranial alveolar soft part sarcoma (PIASPS) represents an exceptionally rare entity. This study aims to characterize its clinical manifestations and evaluate prognostic factors affecting overall survival (OS) and progression-free survival (PFS).

Methods: From 2012 to 2023, Beijing Tiantan Hospital diagnosed and treated 7 cases of PIASPS. Through a systematic PubMed literature review spanning 1988-2023 using the search terms 'primary intracranial alveolar soft part sarcoma,' we identified 17 additional published cases. Pooled analysis of these 24 cases was performed to evaluate prognostic factors affecting OS and PFS.

Results: Our cohort comprised 24 patients (10 males, 14 females) with a mean age of 26.0 ± 16.9 years (range: 3-72 years). With a mean follow-up of 38.2 ± 43.5 months, we observed tumor recurrence in 9 (45%) patients and mortality in 5 (22.7%) patients within 45.3 ± 39.0 months. Survival analysis revealed 1-, 2-, and 5-year OS rates of 100%, 88.5%, and 71.9%, respectively, with corresponding PFS rates of 77.4%, 58.0%, and 41.5%. Both univariate and multivariate Cox regression analyses identified non-gross total resection (Non-GTR) as a significant independent prognostic factor for worse OS (p = 0.031) and PFS (p = 0.009).

Conclusion: Our study demonstrates that PIASPS predominantly affects pediatric and young adult populations without significant gender predilection. Surgical intervention with gross total resection (GTR) was identified as the primary determinant of favorable outcomes, whereas adjuvant radiotherapy and chemotherapy demonstrated limited therapeutic efficacy. These preliminary findings warrant validation through larger, multicenter prospective studies to establish evidence-based management guidelines for this rare entity.