Blood-Based Liquid Biopsies Detect CTCs, Oncosomes in Patients With UTUC

The use of noninvasive blood-based liquid biopsies has shown efficacy in multiple forms of cancer, including kidney and prostate cancers, as an alternative to invasive tissue biopsies, which may cause unwanted risk for patients.

New results from a study led by Alireza Ghoreifi, MD, showed that liquid biopsy can benefit patients with upper tract urothelial carcinoma (UTUC) by detecting rare events at higher incidences compared with tissue-based samples.

Researchers collected blood samples from a group of 28 patients with UTUC before surgery with curative intent and follow-up visits between May 2021 and September 2022. A total of 21 patients gave follow-up blood samples.

The blood samples were analyzed to detect rare events such as circulating tumor cells (CTCs) and oncosomes using the immunofluorescence signals of DAPI (D), cytokeratin (CK), CD45/CD31 (CD), and vimentin (V).

Results from the presurgery liquid biopsies were compared with blood samples from normal donors (NDs) and matched follow-up liquid biopsies. The correlation between liquid biopsy findings and clinical data such as recurrence-free survival (RFS) was also assessed.

Compared with blood samples from NDs, the presurgery samples showed significant differences in specific rare analytes. In a matched analysis of the post- versus presurgery groups, there was a significant decrease in total-, CK-, and CK|V oncosomes, as well as in D-, D|V-, and D|V|CD cells. The median follow-up was 11 months, and 8 patients experienced disease recurrence.

A survival analysis showed that patients with >1.95 preoperative CK|V oncosomes (P=.020) and >4.18 D|CK|V cells (P=.050) had worse RFS compared with other patients.

This initial evidence points to the benefit of utilizing blood-based liquid biopsies for the detection of rare events in patients with UTUC.