Maxillary Sinus Floor Infiltration: Results From a Series of 118 Maxillary Sinus Cancers

Objectives/Hypothesis: Maxillary cancers are rare and aggressive tumors, which can spread beyond the sinus bony walls. Preoperative assessment of infiltration of maxillary sinus floor (MSF) is paramount for surgical planning, as palatomaxillary demolition significantly impacts patients' quality of life. This study investigates the challenges involved in the preoperative and intraoperative evaluation of MSF infiltration and analyzes its prognostic relevance. Study Design: Retrospective case series. Methods: A retrospective review of patients treated for sinonasal malignancies at a single Institution was performed. Patients receiving surgical-based treatment with curative intent for primary maxillary sinus cancers, between January 2000 and November 2019, were included. Results: A cohort of 118 patients was analyzed. By comparing intraoperative findings (endoscopic assessment and frozen sections) with preoperative radiological assessment, diagnostic changes with regard to MSF infiltration were found in 27.1% (32/118 cases). MSF infiltration negatively affected the prognosis in both univariate and multivariate analyses in the overall population. In the subgroup of pT1-T3 tumors, MSF infiltration was significantly associated with reduced overall (P =.012), disease-free (P =.011), and distant recurrence-free (P =.002) survival rates. Conversely, pT classification was not able to stratify patients according to prognosis, mainly because early-staged cancers (pT1-T2) with MSF infiltration showed reduced survival rates, similar to those observed in pT3 cancers. Conclusions: Preoperative imaging should be integrated with intraoperative findings based on endoscopic inspection and frozen sections. Future studies are required to investigate the opportunity to incorporate MSF infiltration in the TNM staging system, considering its crucial role in defining the extent of surgery and its potential as prognosticator. Level of Evidence: 4 Laryngoscope, 132:26–35, 2022.