Long-Term Postoperative Patient-Reported Quality of Life After Endoscopic Surgery for Sinonasal Inverted Papilloma: A Longitudinal Cohort Study.

Background and Objectives: Sinonasal inverted papilloma (IP) is a benign yet locally aggressive tumour associated with a clinically relevant risk of recurrence and malignant transformation. While surgical outcomes are well documented, data on long-term patient-reported quality of life (QoL) remain limited and are often based on short-term or single time-point assessments using disease-specific instruments alone. Materials and Methods: We conducted a single-centre observational cohort study of adults with histologically confirmed IP treated endoscopically. Patients were followed in a university-affiliated otorhinolaryngology outpatient clinic and completed the Sino-Nasal Outcome Test-22 (SNOT-22) at each visit; from 2022 onwards, the generic WHOQOL-BREF questionnaire was additionally administered. Longitudinal SNOT-22 trajectories were analysed using generalised additive models and linear mixed-effects models. In a subgroup of patients, retrospectively recalled preoperative SNOT-22 and WHOQOL-BREF scores were used only for exploratory paired pre-post comparisons. Results: Sixty-nine patients were included. Mean follow-up was 63.1 ± 27.8 months, and recurrence occurred in 21 of 69 patients (30%). A total of 461 postoperative SNOT-22 assessments with complete follow-up time data were included in the longitudinal analysis, with a median of six assessments per patient. Mean postoperative SNOT-22 score was 25.4 ± 19.8, and longitudinal postoperative trajectories showed a largely stable course over time. In the paired exploratory subgroup (n = 34), retrospectively recalled preoperative SNOT-22 scores were higher than postoperative scores, although these exploratory findings should be interpreted cautiously because baseline PROMs were not collected prospectively. Exploratory paired comparisons of WHOQOL-BREF showed higher postoperative scores in the physical, psychological and environmental domains. Conclusions: Patients with sinonasal IP treated endoscopically can achieve favourable and largely stable long-term disease-specific and generic QoL. No single baseline clinical factor showed a clear association with postoperative SNOT-22 scores in the longitudinal models. Combining disease-specific and generic patient-reported outcome measures with longitudinal modelling may support more informed postoperative counselling in this rare, recurrent condition, while structured surveillance remains essential.