Detection of Progression and Regression of Genitourinary Cancers by Circulating Tumor DNA (ctDNA)

Document Type

Conference Proceeding

Publication Date

6-2023

Publication Title

Journal of Clinical Oncology

Abstract

Background: Circulating tumor DNA (ctDNA) are short DNA sequences shed by tumor cells into systemic circulation. The sensitivity and specificity of single ctDNA test to predict relapse or recurrence in solid tumor vary widely and the utility of monitoring serial ctDNA trends has not been well-described in genitourinary cancers. Methods: We conducted a retrospective study including adult patients with genitourinary cancers at the hematology-oncology clinic at William Beaumont - Royal Oak and Troy Hospitals, Michigan from, August 2021 to May 2022, who had ctDNA testing done with imaging available for comparison. We evaluated the correlation between ctDNA test, both single test as well as dynamic trends in value over time, with imaging findings. We also calculated lead time for uptrending ctDNA to detect disease progression compared to imaging. Results: 21 total ctDNA test results from eight patient were included in the study; five had renal cell cancer, two had urothelial cancer and one had prostate cancer. The median age at diagnosis was 62 years (Range: 45-82); 90% were Caucasian and 50% were female. Majority (87.5%) had Stage III or IV disease. Out of the 21 total ctDNA samples, all 16 positive ctDNA results had evidence of disease on corresponding imaging: 13 showed progression while 3 showed regression with residual disease compared to prior imaging. Of the 5 negative ctDNA test results, 2 showed no evidence of disease and 3 showed regression with residual disease on corresponding imaging. Sensitivity and specificity of a single positive ctDNA test to detect evidence of disease on imaging was 84.2% and 100%, respectively. Six patients had multiple ctDNA test results with 12 pairs of serial ctDNA values, of which 9 were up-trending, and 3 were down-trending. Both sensitivity and specificity of up-trending ctDNA values to detect progression and down-trending ctDNA values to detect regression on imaging were 100%. Uptrending ctDNA values predicted disease progression with a median lead time of 55.5 days compared to imaging. Conclusions: Given the high sensitivity and specificity of serial ctDNA monitoring to detect disease progression and regression in our study, we conclude that this may be a valid way to reliably monitor for changes in disease status in genitourinary cancers before they become evident on imaging studies. Further clinical studies are needed to prove its utility in detecting immediate changes in disease status and guide therapeutic intervention in genitourinary cancers.

Correlation of single ctDNA result with disease on imaging.

Volume

41

Issue

16(Suppl.)

First Page

e16508

Comments

American Society of Clinical Oncology Annual Meeting, Chicago, IL, June 2-6, 2023.

DOI

10.1200/JCO.2023.41.16_suppl.e16508 Journal of Clinical Oncology 41, no. 16_suppl (June 01, 2023) e16508-e16508

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