Adamantinomatous craniopharyngioma: outcomes from a US multicenter registry cohort (RAPID consortium study)

OBJECTIVE: Adamantinomatous craniopharyngioma (ACP) is a rare type of brain tumor that affects a wide age range, from children to older adults. Due to the rarity of the disease, existing studies are predominantly limited to single-center or single-surgeon experiences, often lacking statistical power and generalizability. The aim of this study was to address this gap by providing a comprehensive analysis of ACP outcomes based on a large multicenter cohort from the Registry of Adenomas of the Pituitary and Related Disorders (RAPID). METHODS: This multicenter retrospective cohort study was conducted via the RAPID consortium and assessed patients with histologically confirmed ACP treated surgically between August 2000 and November 2024 at high-volume pituitary centers across the United States. RESULTS: Among the 359 patients (206 male, median age at primary surgery of 47 years) included in the analysis, 76% underwent endoscopic transsphenoidal surgery and 22% underwent craniotomy. Gross-total resection was achieved in 45% and subtotal resection in 47%. Notably, 120 of 311 patients (39%) presented with preoperative hypothalamic-pituitary axis dysfunction. Following all treatments, permanent hypothyroidism was reported in 40% of patients, adrenal insufficiency in 33%, and arginine vasopressin deficiency in 19%. Of 263 patients who underwent primary surgery, radiation therapy was administered in 84 (32%). Progression-free survival (PFS) declined from 66% at 1 year to 31% at 6 years. In the multivariable analysis, independent predictors of worse PFS included subtotal resection (HR 0.22, 95% CI 0.11-0.42; p = 0.001), partial resection (HR 0.11, 95% CI 0.04-0.28, p = 0.001), larger tumor size (HR 0.77, 95% CI 0.64-0.94; p = 0.009), and tumor extension beyond the sella and suprasellar regions (HR 0.21, 95% CI 0.06-0.74; p = 0.016). Primary surgery and salvage surgery groups showed comparable PFS. CONCLUSIONS: In this large multicenter cohort study, gross-total resection was achieved in fewer than half of patients and was independently associated with improved PFS. Approximately one-third of patients underwent radiation therapy after primary surgery. These findings provide robust evidence supporting the prognostic value of extent of resection and inform contemporary treatment algorithms for ACP. The high incidence of postoperative endocrinopathy underscores the need for individualized multidisciplinary long-term care. While the retrospective design is a limitation, the multicenter approach enhances the generalizability of these results.