MP61-13 UTILITY OF ctDNA FOR MONITORING TREATMENT RESPONSE IN PENILE AND PRIMARY URETHRAL CANCERS

You have accessJournal of UrologyPenile & Testicular Cancer II (MP61)1 May 2024MP61-13 UTILITY OF ctDNA FOR MONITORING TREATMENT RESPONSE IN PENILE AND PRIMARY URETHRAL CANCERS Sol C. Moon, Kartik Patel, Luke Shumaker, James E. Ferguson, Arnab Basu, and Charles Peyton Sol C. MoonSol C. Moon , Kartik PatelKartik Patel , Luke ShumakerLuke Shumaker , James E. FergusonJames E. Ferguson , Arnab BasuArnab Basu , and Charles PeytonCharles Peyton View All Author Informationhttps://doi.org/10.1097/01.JU.0001009536.58867.87.13AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Monitoring cancer treatment response has traditionally been limited to imaging or biopsies. Circulating tumor DNA (ctDNA) testing has demonstrated efficacy as a prognostic and predictive biomarker for monitoring in several malignancies but its utility for monitoring primary urethral cancer (PUC) or penile squamous cell cancer (pSCC) has not been specifically evaluated. We investigated if serial ctDNA monitoring correlated with clinical response in PUC and pSCC. METHODS: Fifty-eight ctDNA tests using a tumor-informed molecular residual disease assay (Signatera, Natera Inc.) from 13 patients diagnosed with PUC or pSCC were reviewed and their demographic and treatment data were collected. All patients were treated with curative intent and followed with standard imaging and ctDNA testing. Radiographic stability, improvement, or surgical downstaging was considered concordant with negative or downtrending ctDNA results. Disease progression was considered concordant with increasing ctDNA results. Chi-squared testing for univariable analysis and linear regression modeling for ctDNA changes were employed. RESULTS: Mean age was 68 (44–77) years and median follow up was 44.0 weeks (11.3–195.3). Four had pSCC, five had PUC, two had penile and urethral SCC, and two had urethral adenocarcinoma. A swimmer's plot shows staging, longitudinal ctDNA results, duration of systemic therapy, radiation, surgery and outcomes (Figure 1). ctDNA results were concordant in 56 of 58 patients (96%) based on radiographic disease status and/or surgical down-staging (p=0.007). Positive ctDNA tests had an odds ratio for progression of 1.92 (1.45-3.27, p=0.0015). Using stable disease as a reference, linear regression modeling of changes in ctDNA resulted in association values for complete response (B value: −46.2, 95% CI −79.8 to −13.1) and disease progression (B: 31.8, 95% CI 9.1 to 52.2). CONCLUSIONS: Our data shows that tumor-informed serum ctDNA levels are concordant with surveillance imaging and pathologic staging for PUC and pSCC. Monitoring serial ctDNA results may characterize treatment response and disease progression better than conventional methods which can help tailor patient specific therapy and improve outcomes. Download PPT Source of Funding: N/A © 2024 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 211Issue 5SMay 2024Page: e1016 Advertisement Copyright & Permissions© 2024 by American Urological Association Education and Research, Inc.Metrics Author Information Sol C. Moon More articles by this author Kartik Patel More articles by this author Luke Shumaker More articles by this author James E. Ferguson More articles by this author Arnab Basu More articles by this author Charles Peyton More articles by this author Expand All Advertisement PDF downloadLoading ...