Feasibility of Personalized and Tumor-Informed Circulating Tumor DNA Assay for Early Recurrence Detection in Patients With Hepatocellular Carcinoma.

Purpose: Hepatocellular carcinoma (HCC) has high relapse rates after standard-of-care (SOC) resection or liver transplantation (LT). We evaluated the utility of circulating tumor DNA (ctDNA) to predict relapse/progression risk in patients with HCC.

Materials and methods: This retrospective analysis examined real-world data from ctDNA testing on 125 patients with HCC (721 plasma samples) undergoing curative-intent treatments and SOC management. Patients were divided into four subcohorts: cohort A (n = 64) and B (n = 52) comprised patients under recurrence monitoring after LT or resection, respectively. Cohort C (n = 4) and D (n = 5) comprised patients under treatment response monitoring with known recurrence or inoperable disease, respectively. A personalized, tumor-informed 16-plex polymerase chain reaction next-generation sequencing assay (Signatera, Natera, Inc, Austin, TX) was used for ctDNA testing. The molecular residual disease (MRD) window was defined as 2-12 weeks post-LT/resection (cohorts A/B), before starting adjuvant therapy (AT). Surveillance window was defined as post-MRD window or 2 weeks post-AT (cohort B) or during ongoing treatment (cohorts C/D).

Results: The median follow-up was 40 (1.5-60) months. In cohort A, 97.2% (35/36) of patients with ctDNA negativity in the MRD window remained negative during surveillance. In cohort B, ctDNA was detected in 29.4% (10/34) of patients within the MRD window, all of whom experienced clinical recurrence (hazard ratio [HR], 7.2 [95% CI, 2.6 to 20]; P < .0001). In the surveillance window (cohort B), the ctDNA detection rate was 32.3% (10/31), and all experienced recurrence (HR, 18.0 [95% CI, 3.9 to 85]; P < .0001). In cohorts C/D, on-treatment ctDNA dynamics were concordant with treatment response as measured by imaging. Compared with alpha-fetoprotein, ctDNA had higher sensitivity and a significantly longer lead time (7.9 v 2.2 months) for recurrence detection.

Conclusion: Serial ctDNA testing effectively identified HCC recurrence early, postresection and post-LT. ctDNA was also useful for treatment response monitoring and could help resolve ambiguous imaging results.