Abstract

Background: Early recurrence of hepatocellular carcinoma (HCC) after surgical resection compromises patient survival. Timely detection of minimal residual tumor is helpful in recurrence monitoring and evaluating treatment strategies. This study examined the feasibility of virus-host chimera DNA (vh-DNA) generated from integration sites of hepatitis B virus (HBV) in the HCC chromosome as a personalized circulating biomarker for residual tumors after surgery.

Methods: The tumor-specific vh-DNA integration sites were determined in 148 HBV-related HCC patients by capture-based next-generation sequencing (NGS). For each individual HCC, vh-DNA was quantified using a customized droplet digital PCR (ddPCR) assay in plasma samples collected pre-operation and within 14 months after surgery, and the results were compared with the clinical outcomes.

Results: HBV integrations were identified in 132 out of 148 patients with HBV-related HCC (89.2%). The preoperative blood vh-DNA concentration was correlated with tumor size (r=0.73, detection limit at 1.5 cm). Among the 113 patients who completed the postoperative follow-up, the positive predictive value (PPV) of vh-DNA for tumor recurrence was 71% (17/24), and the negative predictive value (NPV) was 92% (82/89). The smallest recurrent HCC with detectable circulating vh-DNA was 0.8 cm, and the average leading time of vh-DNA detection was 158 days earlier than computed tomography scanning. A total of 78% (18/23) of recurrences originated from the same HCC clones sharing the same vh-DNA, suggesting that most of the early recurrence came from residual tumor cells. Moreover, logistic regression analysis showed that vh-DNA was an independent risk factor for predicting early recurrence (P<0.0001). When vh-DNA combined with the serum markers AFP and PIVKA-II, the sensitivity and specificity of recurrent HCC were 95.8% (23/24) and 95.5% (85/89), respectively.

Conclusion: This study demonstrates that vh-DNA can serve as a personalized circulating tumor marker for HBV-related HCC patients. Utilizing vh-DNA to monitor the presence of residual tumors after surgery could be a promising solution for prognosis assessment, recurrence monitoring, and guiding adjuvant therapies in the future.