Recurrence and progression factors of papillary urothelial neoplasm of low malignant potential

Abstract

Objective To investigate the pathological characteristics of bladder low malignant potential papillary urothelial tumors (PUNLMP) and the predic factors of recurrence and pathological progress. Methods We retrospectively analyzed 150 patients of bladder PUNLMP in the Department of Urology of Xijing Hospital from February 2009 to February 2019. Among the 150 patients, 118 patients were males and 32 patients were females. The average age was 57 years, ranging 20-93 years. There were 112 cases of single tumor and 38 cases of multiple tumor. All patients received transurethral resection of bladder tumor (TURBT) and 136 patients received bladder infusion chemotherapy, including 61 patients for pirarubicin, 58 patients for gemcitabine, 11 patients for epirubicin, and 11 patients for mitomycin. 14 patients did not receive bladder infusion chemotherapy. In this study, univariate and multivariate logistic regression analysis were used to investigate independent predictors of recurrence and pathological progression in patients of bladder PUNLMP who received TURBT. Results The average follow-up time was 25.6 months, ranging 5.5-122.7 months. Among the patients, 21 patients occurred recurrence. The recurrent duration ranged from 2.2 to 108.3 months (mean 23.1 months). 12 patients had pathological progression, including 9 patients for low-grade non-invasive papillary urothelial carcinoma, 1 patient for high-grade non-invasive papillary urothelial carcinoma, 1 patient for high-grade invasive urothelial carcinoma, 1 patient for squamous cell carcinoma. The progressive duration ranged from 2.2 to 56.3 months (mean 21.5 months). Among the 150 patients, 18 patients with inverted growth pattern did not recur. There were significant differences in the number of tumors and the tumor length between the recurrence and non-recurrence groups, same as the progression and non-progression groups. The univariate and multivariate logistic regression analysis results showed that the number of tumors was an independent predictor of tumor recurrence (OR=7.884, 95%CI 2.815-22.082, P<0.05)and progression(OR=6.107, 95%CI 1.659-22.473, P=0.006) in patients of bladder PUNLMP. Bladder infusion chemotherapy failed to reduce the risk of recurrence and progression. Conclusions About 14% (21/150) patients of bladder PUNLMP reoccurred after TURBT. About half of them had pathological progression, and most of them progressed to low-grade non-invasive papillary urothelial carcinoma. Multiple tumors was an independent risk factor for postoperative recurrence and progression. Bladder infusion chemotherapy did not reduce the risk of recurrence and progression in patients of bladder PUNLMP. Key words: Urinary bladder neoplasms; Papillary urothelial neoplasms of low malignant potential(PUNLMP); Recurrence; Progression