Comparison of Current Staging Systems for Sinonasal Inverted Papilloma

Abstract

Background A staging system is essential for determining the optimal surgical approach and predicting postoperative outcomes for inverted papilloma (IP). Although staging systems based on the extent to which the location is occupied by an IP have been widely used, an origin site-based classification of IP using unsupervised machine learning algorithms has recently been reported. Objective To determine the most appropriate of five staging systems for sinonasal IP by comparing recurrence rates for each stage according to each of those systems. Methods Eighty-seven patients with sinonasal IP were enrolled in the study. Their tumors were retrospectively categorized according to the Krouse, Oikawa, Cannady, and Han staging systems, which are based on the extent of IP, and the Meng system, which is based on the site of origin. The rates of recurrence for each stage of the five systems were compared. Results Seven of the 87 patients (8.0%) had recurrences during an average 45.5 months (12–138 months) of follow-up. There were significant differences in disease-free survival between the stages specified by Han and Meng (p = 0.027 and p < 0.001, respectively), but not between the stages specified by Krouse, Oikawa, and Cannady (p = 0.236, 0.062, and 0.130, respectively). Cox proportional hazard models revealed that Meng system (adjusted hazard ratio [aHR] 4.32, 95% confidence interval [CI] 1.10–17.04) and presence of dysplasia (aHR 7.42, 95% CI 1.15–47.85) were significantly associated with recurrence. Conclusion The staging systems proposed by Han and Meng were found to be accurate in terms of tumor recurrence. We recommend use of the Han staging system before surgery and the Meng system after intraoperative identification of the origin of the tumor.

Sinonasal inverted papilloma – malignant transformation and non‐sinonasal malignancies

“…However, a recent meta‐analysis found a significant increase in recurrence rate when Krouse stage T3 was compared to stage T2, but no significant difference in the recurrence risk was found between Krouse stage T1 and T2 or T3 and T4 2 . Nakayama et al did not find a significant difference in disease‐free survival between stages defined by Krouse 22 . Interestingly, the vast majority of the multifocal tumors in our study recurred.…”

“…2 Nakayama et al did not find a significant difference in disease-free survival between stages defined by Krouse. 22 Interestingly, the vast majority of the multifocal tumors in our study recurred. Krouse classification does not consider the multicentricity of the tumor.…”

International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors

“…Of the 35 included studies, 22 studies reported RFS and time to recurrence. For all tumors, the mean time to recurrence ranged from 8 to 138.1 months, with the majority of the recurrences occurring within the first 5 years ,216,369,373,402,418,419,431,701,720,721,741,1086,1135,1153,1161,1166 , 1397,1417,1931,2194–2201 . Notably this group consists of benign and malignant tumors, including ACC and ONB, known for late recurrence.…”

“…There are no studies evaluating the ideal timing for clinical follow‐up in patients with sinonasal tumors; however, many authors report their follow‐up protocols 216,369,373,402,418,419,431,1153,1161,2194,2195 . Despite being institutionally dependent, there are a few themes that may be highlighted.…”

A Lot Can Happen in a Year

“…Nakayama et al. 23 investigated the accuracy of five staging systems: Krouse, Oikawa, Cannady, Han, and Meng, for predicting postoperative outcomes for inverted papilloma. Based on recurrence rates in 87 patients with sinonasal inverted papilloma, the authors recommend the Han staging system before surgery and the Meng system after intraoperative identification of the origin of the tumor.…”