Can Imaging Response following Neoadjuvant Chemotherapy in Upper Tract Urothelial Cancer be a Surrogate for Pathologic Response?
Pathological response following neoadjuvant chemotherapy (NAC) has been shown to be an excellent surrogate for survival in bladder cancer. In upper tract urothelial cancer (UTUC), unlike bladder, preoperative endoscopic and pathologic assessment of response is difficult. The aim of this study is to determine whether imaging response following NAC predicted the final pathologic stage and outcomes following radical nephroureterectomy (NU).
We identified all radical nephroureterectomies performed at our institution from January 1995 until July 2017. All cytology and biopsy proven, ≥cT2anyNM0 high grade UTUC patients who underwent NAC with cisplatinum based chemotherapy prior to RNU were analyzed. Evaluation with CT/MR urography was available both before and after NAC. Radiological response rate (RRR) was estimated using the RECIST criteria and pathologic response was defined as
Of the 685 NUs performed during the study period, 62 (9.1%; 95% CI 7.1%, 12%) underwent cisplatin based NAC prior to surgery. Patients who underwent NAC were younger at the time of NU (median of 66 years vs 71 years, p=0.0001) and had their NU in the more recent years (median surgery year of 2013 vs 2007, p<0.0001) than patients who did not undergo cisplatin-based NAC. Response rates on imaging were: 16% complete response; 52% partial response; 27% stable disease; 5% progression. Thirty-six patients (58%; 95% CI 45%, 70%) responded to cisplatin-based chemotherapy on pathology. Radiological response was significantly associated with lower tumor stage on pathology (74% among complete or partial response vs 25% among stable disease or progression, p=0.0004. On multivariable analysis, radiological response was associated with better overall survival (HR 0.48) although confidence intervals were wide (95% CI 0.17, 1.31; p=0.2) due to low event rates (16 deaths). </p>
Radiological response rates following NAC in UTUC is significantly associated with pathologic response and non-significantly associated with better overall survival following NU. It can be a useful preoperative tool to counsel and optimize management of UTUC patients.