Nomograms Predictive of Recurrence in Malignant Tumors Treated With Skull Base Surgery: An International Collaborative Study

Background: This study aimed to develop predictive models for local (LR), regional (RR), and distant recurrence (DR) after skull base surgery for primary malignant tumors. Methods: We analyzed 2179 patients (1995–2015) from an international multicenter database, split into training (n = 1297) and validation (n = 882) cohorts. Cox regression identified predictors of LR, RR, and DR, and nomograms were developed and validated using concordance indexes (C-indexes). Results: Median age was 56 years; 64% were male. The most common sites included the ethmoid sinus (38%), nasal cavity (25%), and maxillary sinus (20%). Squamous cell carcinoma was the most frequent histology (25%). LR predictors included brain invasion, higher-risk histology, pT3/T4, pN+, positive margins, and adjuvant therapy (protective). RR predictors included high-risk histology, pT3/T4, and pN+. DR predictors mirrored LR except for adjuvant therapy. C-indexes were around 0.7 for all endpoints. Conclusions: These validated nomograms provide useful tools for recurrence risk stratification and personalized management.