Survival of Patients with Sinonasal Cancers in a Population-Based Registry, Lombardy, Italy, 2008-2023.

Sinonasal cancers (SNCs) are rare malignancies associated with occupational exposures. The aim of this study was to analyse the survival of SNC patients using data from the population-based SNC registry of the Lombardy region (10 million people), Italy. We included epithelial SNC cases registered in 2008-2020 and followed-up for vital status until 31 July 2023. Multivariate flexible parametric models with time-dependent covariates were fitted to calculate excess hazard ratios (EHRs) and 95% confidence intervals (CIs) of death. Based on 827 cases (553 males, 274 females) and 514 deaths (345 males, 169 females), the 5-year observed survival was 49% and the net survival was 57%. Age had a substantial impact on survival, particularly within the first year (EHR, 1.35; 95% CI, 1.12-1.51 per 10 years). Compared with the nasal cavity, the EHR for paranasal sinuses was 4.70 (95% CI, 2.96-7.47) soon after diagnosis. Compared with squamous cell carcinomas, the EHR was 0.69 (95% CI, 0.52-0.91) for adenocarcinomas, 1.68 (95% CI, 1.20-2.35) for undifferentiated and unspecified carcinomas, and 1.78 (95% CI, 1.07-2.95) for neuroendocrine carcinomas. Age and cancer site showed time-dependent effects on prognosis, especially within the first month after diagnosis. Prognosis was also markedly affected by cancer morphology. No associations were found for gender and period of diagnosis.