PD31-09 CLINICAL FACTORS PREDICTING PATHOLOGICAL POSITIVE LYMPH NODES IN CLINICALLY NODE NEGATIVE PATIENTS TREATED WITH NEOADJUVANT CHEMOTHERAPY AND RADICAL CYSTECTOMY

Abstract

INTRODUCTION AND OBJECTIVES: Following radical cystectomy (RC) for urothelial carcinoma (UC) of the bladder cancer, a proportion of clinically node negative patients will be diagnosed with metastasis in the regional lymph nodes (pNþ). A number of clinical factors such as local stage and lymphovascular invasion (LVI) have been identified as potential predictors for pNþ status; however, these have not been assessed in patients treated with neoadjuvant chemotherapy (NAC). Our objective is to assess clinical and therapeutic factors predicting pNþ in clinically node negative patients treated with NAC and RC. METHODS: Patients from four North American institutions with cT2-4N0M0 UC who received three or four cycles of NAC followed by RC were included. A logistic regression model was formulated for predicting pNþ status. The variables included were age, gender, clinical T-stage, transurethral resection (TUR) histology (UC or UC variant) and LVI, number of cycles of NAC, the regimen administered and the extent of pelvic node dissection. RESULTS: The analysis was conducted on 238 patients. Median age was 64 years (IQR: 58-71) and 79% of patients were male. The clinical stage was cT2 in 143 (60.1%), cT3 in 76 (39.1%) and cT4 in 19 (8%) cases. MVAC was used in 26.9% and GC in the remainder of the patients. 60.9% of the MVAC group received four cycles of NAC compared to 42.5% of the GC group (p1⁄40.013). Pathological Nþ was seen in 45 (19.5%) patients. In the logistic regression analysis, cT4 stage (OR: 3.32, [95% CI: 1.15-9.56]) and the fewer cycles of NAC (3 vs. 4 cycles OR: 2.10, [95% CI: 1.03-4.29]) were significant predictors of pNþ status. LVI was not significant in this cohort of patients (OR: 1.15, [95%CI 0.50-2.63]). The observed advantage of the additional cycle of NAC was persistent in subanalysis of the GC patients (OR: 2.67, [CI: 1.11-6.41]) but not MVAC patients (OR: 1.11, [CI: 0.25-4.92]). CONCLUSIONS: Patients with locally advanced disease are at higher risk of harboring lymph node metastasis at the time of RC following NAC. LVI in the TUR specimen was not a significant predictor of nodal metastasis in these patients. Potential advantage of an additional cycle of NAC in GC patients requires further confirmation.