Comparison of outcomes between patients with de-novo sinonasal squamous cell carcinoma vs malignant transformations from inverted papillomas.

BACKGROUND: The survival difference between de-novo sinonasal squamous cell carcinoma (DN-SNSCC) and SCC arising from inverted papillomas (IPs) is unclear. The purpose of this study was to compare the outcomes between DN-SNSCC and IP-transformed SNSCC (IP-SNSCC) patients. METHODS: In this retrospective review, we compared IP-SNSCC and DN-SNSCC cases from the Eye and ENT Hospital of Fudan University from 2010 to 2017. A total of 162 patients (39 IP-SNSCC and 123 DN-SNSCC) were included in our study. Demographics, tumor characteristics, treatment, and clinical outcomes were analyzed. RESULTS: The median follow-up time in all cohorts was 56 (range, 5-109) months. There was no difference in age, sex, smoking history, alcohol consumption, tumor primary site, or disease stage between the IP-SNSCC and DN-SNSCC patients. We also did not find significant differences in overall survival and disease-free survival between IP-SNSCC and DN-SNSCC patients (p = 0.584 and p = 0.238, respectively). The 5-year local failure rate was 52.8% for IP-SNSCC patients, which was significantly higher than for those with DN-SNSCC (31.9%; p = 0.013). The 5-year nodal failure rate was 19.0% for IP-SNSCC patients and 8.5% for DN-SNSCC patients (p = 0.211). The 5-year distant metastasis rate was 8.0% for IP-SNSCC patients and 16.1% for DN-SNSCC patients (p = 0.318). CONCLUSION: IP-SNSCC and DN-SNSCC patients have similar survival outcomes. IP-SNSCC seems to have exhibited a higher local failure rate in our study. We believe that IP-SNSCC is a highly aggressive disease that requires radical treatment. Prophylactic neck treatment should not be omitted in a subset of IP-SNSCC patients.