Sinonasal intestinal-type adenocarcinoma: Multi-institutional retrospective analysis based on 440 patients with long-term follow-up

Background: Sinonasal intestinal-type adenocarcinoma (ITAC) is the most common nasoethmoidal cancer in European countries. Subtypes and other prognostic factors/parameters are known to be associated with prognosis. Methods: We performed a retrospective analysis of prognostic factors associated with overall survival (OS), cancer-specific survival (CSS) and disease-free survival (DFS) in patients affected by histologically-proven sinonasal ITAC, managed with an endoscopic surgery-centered protocol in 6 European centers. A prognostic study with multivariable analysis was performed. Results: Mean follow up was 74 months. 5-year CSS was 81.7 %, varying substantially according to the histologic subtype, ranging from 94.8 % for well differentiated tubulo-papillary subtype to 32.7 % for signet-ring cell ITAC. Whole group 5-year recurrence rate was 30.8 %, ranging from 18.7 % for well differentiated tubulo-papillary subtype to 73.8 % for signet-ring cell ITAC. Conclusion: Considering ITAC as a single entity is no longer advisable, as different subtypes carry remarkably different prognosis. Until novel, standardized biomarkers will be available, ITAC management needs to be customized upon several factors, with histopathology-based subtyping being exceedingly relevant.