Abstract LB105: Sensitive urothelial cancer detection via high volume urine DNA analysis

Abstract

Abstract Background: The detection of cancer-associated DNA in urine samples has significant potential in urothelial cancer (UC) detection and surveillance. Every year millions of patients with urinary symptoms undergo cystoscopy, an examination of the bladder using a flexible scope. Only 10% of these invasive examinations result in a cancer diagnosis. Cystoscopy is also used in post-operative surveillance, with many UC patients requiring life-long cystoscopies. Methods: We developed a high-volume urine DNA collection kit and laboratory platform and prospectively analyzed 433 urine samples collected from diagnostic and post-operative timepoints from 167 UC patients and 95 negative controls from January 2021 to September 2023. We used a hybridization capture assay targeting the coding regions of 21 commonly mutated genes in urothelial tumors, as well as 8 frequently copy number altered loci. Samples were sequenced using Illumina NovaSeq instruments. Mutations, copy number alterations, and chromosomal rearrangements were computationally identified. Key Findings: In the diagnostic settings our assay achieved a sensitivity of 100% for pT1+ bladder cancer, 97% for pTa bladder cancer, and 91% for upper tract urothelial cancer (UTUC) (100% for pT1+ or high grade) in an all-comers UC cohort, at a specificity of 93%. Post-operative urine DNA surveillance informed by preoperative urine mutations detected 28/30 (93%) residual cancer cases found in cystoscopy or surgery, with two pTa low grade recurrences missed. Using a secondary, highly stringent urine tumor DNA detection threshold (100% specificity for UC), we show that urine DNA testing in the diagnostic setting may allow up to 68% of UC patients to be scheduled directly to operating room procedures, reducing hospital workload and expediting care. In addition, we demonstrate the feasibility of urine DNA for detecting underlying Lynch syndrome in UC patients by identifying three UTUC patients who carried germline defects in mismatch repair genes MSH2 or MSH6, indicative of Lynch syndrome. In two of these patients our assay also found a somatic second hit and high mutation load. Conclusions and Clinical Implications: These results show promise in urine DNA based cancer diagnostics even in patients with low grade tumors. The assay is designed to offer a non-invasive and cost-effective alternative for cystoscopies. Citation Format: Jussi Nikkola, Lauri Ryyppö, Juuso Vuorinen, Heini Kallio, Hanna Selin, Pyry Jämsä, Jonne Åkerla, Tarmo Pekkarinen, Antti Kaipia, Matti Nykter, Thea Veitonmäki, Matti Annala. Sensitive urothelial cancer detection via high volume urine DNA analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB105.