Cao, Xiaoming

Abstract Objective: Upper tract urothelial cancers (UTUC) can be difficult to characterize, and non-invasive surveillance tools are lacking. UTUC are often treated with nephroureterectomy (NU). To address these gaps, we sought to discover and validate methylated DNA markers (MDMs) for detection of UTUC. Methods: Archival formalin fixed paraffin embedded (FFPE) tissue samples from NU were pathologically reviewed and punched prior to DNA extraction. Reduced representation bisulfite sequencing (RRBS) was used to identify candidate MDMs that discriminated between UTUC and age-balanced control urothelial tissues (uninvolved ureter/renal pelvic of renal cell carcinoma at radical nephrectomy). Highest ranked (fold-change and p-value) candidate MDMs were biologically validated by quantitative methylation specific PCR in a 2nd independent set of UTUC and age-balanced controls. DNA from healthy donor urine and buffy coat samples was used to assess MDM background signal. Discrimination between UTUC and controls was assessed as the area under the receiver operator characteristic curve (AUC) with corresponding 95% confidence intervals. Results: RRBS assessed 33 UTUC and 26 ureter/renal pelvis controls. 3.01 x 106 CpGs mapped to the reference genome with at least 10X read depth. From 358 candidates, 20 MDMs were selected for biological validation in independent patient samples which included 20 renal pelvis & 16 ureter UTUC and 17 renal pelvis & 15 ureter control specimens. Of UTUC and control patients, 36% and 65% of were men, respectively. Median AUC for comparison of UTUC vs control tissue was 0.87 (IQR 0.81-0.88); AUCs with corresponding 95% CIs are shown for the 10 most accurate MDMs (Table) across all control types. Conclusion: We report discovery and validation of highly sensitive and specific MDMs with potential for accurate non-invasive screening supported by low background in urine and blood. AUCs (95% CI) for selected methylated DNA markers for UTUC vs control tissue, urine, and blood UTUC vs Marker Control Tissue Control Urine Control Buffy C2orf55 0.92 (0.84-1) 0.93 (0.87-1) 0.96 (0.91-1) ANKRD35 0.91 (0.84-0.99) 0.93 (0.86-1) 0.98 (0.94-1) DLX6 0.91 (0.84-0.98) 0.78 (0.66-0.9) 0.97 (0.93-1) Chr8.9998 0.90 (0.82-0.97) 0.91 (0.84-0.97) 0.98 (0.96-1) SP9 0.88 (0.8-0.97) 0.95 (0.9-1) 0.99 (0.98-1) Chr13.1127 0.88 (0.8-0.97) 0.94 (0.89-1) 0.92 (0.85-1) Septin9.r2 0.88 (0.79-0.97) 0.95 (0.88-1) 0.98 (0.94-1) LBX2 0.88 (0.79-0.97) 0.94 (0.88-1) 0.96 (0.91-1) SIM2.r1 0.88 (0.79-0.97) 0.91 (0.82-1) 0.94 (0.86-1) Chr14.1037 0.88 (0.78-0.97) 0.93 (0.85-1) 0.96 (0.9-1) Citation Format: Ojas Bhagra, William R. Taylor, Benjamin R. Gochanour, Patrick H. Foote, Calise K. Berger, Xiaoming Cao, Douglas W. Mahoney, Sara S. Then, Anna M. Gonser, Karen A. Doering, Kelli N. Burger, John C. Cheville, Matthew T. Gettman, John B. Kisiel. Discovery and validation of methylated DNA markers of upper tract urothelial tract cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3349.

9567 Background: Cutaneous melanoma surveillance is important to identify low-volume systemic disease, but imaging is costly and poorly accessible to patients; frequent skin checks lack sensitivity and specificity. We aimed to establish clinical feasibility of a liquid biopsy blood test, which quantifies validated, melanoma-specific, methylated DNA markers (MDMs), previously discovered, and reported by our team, using tissue extracted DNA. Methods: We prospectively collected blood from adult patients with histologically confirmed melanoma metastases and no other internal malignancies (within 5-years) who underwent surveillance by FDG-PET/CT (N = 88). Blood from age- and sex balanced cancer-free controls (N = 100) were compared. From PET/CT, we extracted the number of organs involved, SUV-max, and largest tumor diameter. Unequivocal metastasis was defined as SUV ≥ 4 and largest diameter > 5 mm. Because PET/CT is inadequate for the screening of brain metastases, we excluded the brain from the analysis. MDMs ( chr11.149, HOXA9, chr20.210, FLJ22536, CLIC5, SIX4, chr7.155, chr17.730, chr1.110) were assayed using target enrichment long-probe quantitative-amplified signal assays, normalized to B3GALT6, in blinded fashion. Using a logistic regression approach and nine candidate MDMs, we calculated the sensitivity for detecting patients with metastasis on PET/CT at 100% specificity. Results: 52/88 (59%) of melanoma patients showed evidence of metastasis on PET/CT at the time of blood draw. At 100% specificity, a panel of 4 MDMs ( HOXA9, chr20.210, chr17.730, chr1.110) yielded a sensitivity of 86.5% (45/52 cases) vs. 100 cancer-free controls. When applying this model to the 36 PET/CT-negative patients, specificity was as high as 97.2% (35/36 cases) while maintaining a sensitivity of 86.5% (one patient with a positive test result had a complete metabolic response to binimetinib / encorafenib prior to negative PET/CT). For patients with ≥ 2 organs involved by metastasis, sensitivity was 100% (29/29 cases). False-negative cases had metastasis in single organs and were characterized by minimal tumor burden and oral corticosteroid use. One false-negative patient had localized stage III disease without known primary melanoma. Conclusions: Plasma MDM levels appear highly concordant with FDG-PET/CT in patients with metastatic cutaneous melanoma. A liquid biopsy approach has potential to lower cost and improve patient access to surveillance. Additional prospective studies in larger intended use cohorts are needed to validate our results.