2399P - Circulating tumor DNA and urine tumor DNA detection of minimal residual disease in upper tract urothelial carcinoma with radical nephroureterectomy: A cohort study

Background

Upper tract urothelial carcinoma (UTUC) is an aggressive disease with poor prognosis that is often diagnosed late. At present, circulating tumor DNA-based minimal residual disease (MRD) has been studied in blood from varies solid tumors but its clinical value in monitoring urinary tumor DNA (utDNA) during adjuvant therapy in postoperative UTUC remains unclear.ma va.

Methods

The OriMIRACLE S^TM MRD assay (OrigiMed, Shanghai, China) uses whole exome sequencing (WES) for detecting patient-specific somatic alterations from tumor tissues and for blood a personalized panel.

Results

Nineteen patients with stage II UTUC were enrolled in this study, excluding one death due to COVID-19. By monitoring ctDNA and utDNA, the baseline positive rates were 69.2% (9/13) and 88.9% (8/9), respectively. One month after surgery/before adjuvant therapy, the positive rates of ctDNA and utDNA decreased to 46.2% (6/13) and 21.4% (3/14), respectively. During adjuvant chemotherapy/6 months after immunotherapy, the positive rates of ctDNA and utDNA further decreased to 35.7% (4/14) and 21.4% (3/14), respectively. At the end of adjuvant chemotherapy/12 months after immunotherapy, the positive rates of ctDNA and utDNA were 36.4% (4/11) and 11.1% (1/9), respectively. At the 6-month follow-up, the positive rates of ctDNA and utDNA were both 25% (1/4). Three patients experienced disease recurrence. One of them tested negative for ctDNA twice in a row and positive for utDNA. Half a month later, the patient underwent cystoscopy and was found to have a bladder full of hair-like and carpet-like new organisms, indicating intravesical recurrence. A patient tested positive for ctDNA twice in a row, but negative for utDNA, and reexamination suggested recurrence. The third patient had positive results for both ctDNA and utDNA, and PET-CT indicated the possibility of tumor metastasis and recurrence.

Conclusions

Our preliminary results suggest ctDNA combined with utDNA detection can serve as predictive biomarkers for UTUC recurrence and can enable the prediction of adjuvant therapy efficacy.

Clinical trial identification

RenJiH-PDU Trial.

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.