MP40-06: Role of Neoadjuvant chemotherapy in pathological downstaging during Radical Nephroureterectomy for Upper Tract Urothelial Carcinoma (ROBUUST collaborative group)

Nicholas Corsi*, Marcus Jamil, Sohrab Arora, Deepansh Dalela, Detroit, MI, Riccardo Auturino, Richmond, VA, Chandru Sundaram, Indianapolis, IN, Robert Uzzo, Philadelphia, PA, Alex Mottrie, Aalst, Belgium, James Porter, Seattle, WA, Daniel Eun, Philadelphia, PA, Koon Rha, Seoul, Korea, Republic of, Amit Satish Bhattu, Miami, FL, Zhenjue Wu, Shanghai, China, People's Republic of, Andrea Minervini, Florence, Italy, Matteo Ferro, Milan, Italy, Giuseppe Simone, Rome, Italy, Ithaar Derweesh, La Jolla, CA, Vitaly Margulis, Dallas, TX, Hooman Djaladat, Los Angeles, CA, Andrew Katims, New York, NY, Firas Abdollah, Detroit, MI

Introduction: One of the primary roles of neoadjuvant chemotherapy (NAC), best demonstrated in muscle-invasive bladder cancer, is pathologic downstaging of the tumor, improving oncological control. Given the impaired renal dysfunction following radical nephroureterectomy (RNU), which may reduce the tolerability of subsequent adjuvant chemotherapy regimens, NAC may offer clinical benefits through pathological downstaging. We hypothesize that the addition of NAC for RNU is associated with a higher probability of pathological downstaging.

Methods: Patients were selected from an international cohort of 17 institutions across the United States, Europe, and Asia (RObotic surgery for Upper Tract Urothelial Cancer Study, ROBUUST) undergoing RNU for UTUC from 2006-2019. Of these, 576 had complete data, and were divided into 50 who received neoadjuvant chemotherapy versus 526 who didn’t. Univariable and multivariable logistic regression adjusted to available covariates, and tested the relationship between NAC status and the two following endpoints: 1) pathologic downstage (pDS), which was pathologic tumor stage (pT) that was at least 1 stage lower than the pre-NAC clinical stage (cT); 2) complete downstaging, defined as the absence of UTUC in both the primary tumor and accompanying nodes (pT0N0) on final pathology.

Results: Average age (standard deviation) was 72 (±10) years. Most patients were males (60%), white (64%), and had cT1 disease (59%). Patient who received NAC were less frequently white (64% vs 58%, p<.001), and harbored less frequently =cT2 disease (28% vs 32%, p=0.002) than their counterparts who didn’t receive NAC. Moreover, NAC patients had higher rates of downstaging (10% vs 4.9%, p=0.1), and complete downstaging (4% vs 0.7%, p=0.03) than their non-NAC patients. Similar findings were observed on multivariable analysis

Conclusions: Our findings in a multi-institutional series suggest that NAC before RNU increase the probability of downstaging (albeit not statistically significant), and complete downstaging (pT0N0) at final pathology. While these findings should be interpreted within the framework of a retrospective study, they are encouraging and suggest that NAC can improve cancer control outcomes.

Source of Funding: None