687 BIMODAL PATTERN OF THE IMPACT OF BODY MASS INDEX ON CANCER-SPECIFIC SURVIVAL OF UPPER URINARY TRACT UROTHELIAL CARCINOMA PATIENTS: MULTI-CENTER STUDY IN A 1114-CASE TOKYO METROPOLITAN DATABASE OF UROLOGIC DISEASE (TMDU) COHORT

UTUC database and the UTUC collaboration (n 4137). After excluding the nine patients who we previously reported on [5], 28 patients (0.7%) with pT0 tumor were included in this report. All patients had undergone cystoscopy, urine cytology, intravenous urography and/or abdominalpelvic CT-scans, and diagnostic ureteroscopy prior to RNU. None of the patients underwent preoperative radiotherapy and none of the patients had metastasis at time of RNU. Due to the low number of patients, only descriptive results are shown. RESULTS: The median age at diagnosis was 68 years (IQR: 57-74) and the male-to-female ratio was 2:1. Six patients had evidence of non-organ confined UTUC on pre-RNU imaging and received neoadjuvant cisplatin-based combination chemotherapy. Regional lymphadenectomy was performed in the six patients who had received neoadjuvant chemotherapy (median: 10 lymph nodes, IQR 6-14). On final pathology, all patients had pT0N0 except one patient who had two positive renal hilar lymph nodes (pT0 N1). Overall, 4 patients experienced disease recurrence (median time to recurrence : 38 months, IQR: 24-48). Three of these patients developed metastatic disease and one had a relapse in the operative field. The three patients with metastasis died from UTUC within a median time of 10 months from their disease recurrence. Within a median follow-up of 40 months (IQR: 22-64), nine patients developped intravesical recurrence (median time: 35 months, IQR: 14-54). The 5-year recurrence-free and cancer-specific survival rates were 77% (95% CI, 72-81.3) and 78% (95% CI, 69-83.8), respectively. CONCLUSIONS: pT0 UTUC may be the result from effective neoadjuvant chemotherapy, complete endoscopic treatment, misinterpretation of the pathologic specimen (i.e, false pT0), or overtreatment. Our limited data shows that post-RNU prognosis of pT0 patients is highly variable as some patients experience disease progression needing more stringent follow-up.