A study being presented at the Society of Urologic Oncology Annual Meeting demonstrated evidence for the clinical utility of blood-based liquid biopsy biomarkers in the diagnosis and surveillance of patients with upper tract urothelial carcinoma (UTUC).
Currently, imaging and laboratory modalities have suboptimal accuracy for diagnostics and prognostics in patients with UTUC. Blood-based liquid biopsy may have the potential as a novel biomarker to improve the diagnosis and monitoring of urothelial tumors, as well as individualized risk stratification.
Alireza Ghoreifi, MD, and colleagues designed a study to systematically visualize and characterize rare events—such as circulating tumor cells (CTCs) and oncosomes—in the peripheral blood from primary UTUCs. They hoped to assess the efficacy of these biomarkers in the diagnosis, surveillance, and prognosis of these patients.
The prospective study included peripheral blood samples from 28 patients with UTUC prior to undergoing extirpative surgery with curative intent. Follow-up visits (n=21) occurred between May 2021 and September 2022.
Researchers analyzed the samples using the third-generation, comprehensive, high-definition, single-cell assay (HDSCA3.0) to detect rare events, including CTCs and oncosomes based on the immunofluorescent signals of DAPI (D), cytokeratin (CK), CD45/CD31 (CD), and vimentin (V).
The presurgery liquid biopsy findings were compared with 50 blood samples of normal blood donors. Follow-up liquid biopsy findings were compared with the presurgery results.
Researchers also assessed a correlation between liquid biopsy findings and progression-free survival (PFS).
Results showed significant differences in specific rare analytes—including total oncosomes, D|V cells, total events, total cells, CK oncosomes, D|CK|V|CD cells, total CK cells, D|V|CD cells, CK|CD oncosomes, and D-only cells—were detected in presurgery samples compared with samples from normal blood donors. On the postsurgery versus presurgery matched analysis, a significant decrease was detected in total, CK, and CK|V oncosomes, as well as D, D|V, and D|V|CD cells.
After a median follow-up of 11 months, researchers reported that 7 patients had disease recurrence, and patients with positive preoperative CK|V oncosomes and those with postsurgery versus presurgery positive change in CK|V oncosome levels had worse PFS compared with other patients (P=.02 and P=.009, respectively).
While this study demonstrates “positive evidence” for the utility of blood-based liquid biopsy biomarkers in the diagnosis and surveillance of patients with UTUC, as well as suggests the ability of presurgery CK|V oncosome levels to predict PFS, further research with “a larger sample size, additional follow-up samples, and a more comprehensive genomic analysis” is needed, researchers concluded.