MP18-12 ONCOLOGIC SURVEILLANCE AFTER RADICAL NEPHROURETERECTOMY IN UPPER TRACT UROTHELIAL CARCINOMA PATIENTS: A NOVEL RISK-BASED APPROACH

INTRODUCTION AND OBJECTIVES: To develop a surveillance protocol with improved cost-effectiveness after radical nephroureterectomy (RNU), as the cost-effectiveness of oncological surveillance after RNU remains unclear.METHODS: We retrospectively evaluated 426 patients with RNU for upper tract urothelial carcinoma (UTUC) without distant metastasis at 4 hospitals.Patients with routine oncological follow-up were stratified into normal-, high-and very high-risk groups according to a pathology-based protocol utilizing pathological stage, lymphovascular invasive(LVI)and surgical margine(SM).Cost-effectiveness of the pathology-based protocol was evaluated, and a risk score-based protocol was developed to optimize cost-effectiveness.Risk scores were calculated by adding risk factors independently associated with recurrence-free survival.Patients were stratified by low-, intermediate-and high-risk score.Estimated cost per recurrence detected by risk scorebased protocols was compared.RESULTS: Of 426 patients, 109 (26%) and 113 (27%) experienced visceral and intravesical recurrences, respectively.The pathology-based protocol found significant differences in recurrence-free survival in the visceral recurrence but not in the intravesical recurrence.The medical costs per visceral recurrence detected were high, especially in normal-risk (¼pT2N0, LVI-, SM-) patients.We developed a risk score associated with visceral recurrence using Cox regression analysis.The risk score-based protocol was significantly more cost-effective than the pathology-based protocol.Estimated cost differences reached $747,929 per visceral recurrence detected, a suggested 55% reduction.CONCLUSIONS: A risk score-stratified surveillance protocol has the potential to reduce overinvestigation after RNU without adverse effects on medical cost.