Background: Malignancies of the liver and bile ducts are associated with high recurrence rates after surgery and poor prognosis when disseminated. Medical treatment has been improved in recent years, with chemotherapy, targeted therapy and checkpoint inhibitors offering opportunities to influence the course of the diseases. Many patients do not benefit from treatment, however, and predictive and prognostic markers are lacking. The BILe duct and LIver cancer: ON-treatment Surveillance of Tumor evolution And Response to Systemic treatment (BILLIONSTARS) study aims to map how molecular tumor characteristics and pathways of genetic evolution align with treatment response trajectories.

Methods: The BILLIONSTARS study is a prospective, single arm observational study. Patients at Skåne University Hospital in Malmö/Lund and Central Hospital in Kristianstad diagnosed with hepatocellular carcinoma (HCC) or cholangiocarcinoma (CCC) who are to be recommended locoregional intervention by surgery, ablation, transarterial chemoembolization or selective internal radiation therapy and/or antitumoral medical treatment will be included. Tissue obtained in the clinical setting through surgery or biopsy along with tissue from research autopsies will be evaluated with targeted deep sequencing. Circulating tumor DNA (ctDNA) and other relevant biomarkers will be analyzed in blood samples obtained at different timepoints, depending on the type of treatment; before surgery or the start of systemic treatment, prior to each course of systemic treatment, if applicable, and at end of treatment.

Discussion: The treatment field for HCC and CCC is evolving, thus improving outcomes for patients in the palliative setting. The efficacy of targeted therapy and checkpoint inhibition is however highly variable, and no predictive biomarkers have yet been established. The clinical course of the diseases is also highly variable and unpredictable. With this study, we hope to gain an increased insight into the various biological characteristics of these tumors, including novel potential treatment targets, as well as their spatial and temporal heterogeneity. By conducting research autopsies with comprehensive post-mortem sampling, we expect to further expand our understanding of the molecular events leading to terminal disease. The ultimate goal is to design better individualized and adaptive treatment strategies, thereby improving the outlook for patients with HCC or CCC.

Trial registration: This study has been registered in clinicaltrials.gov as NCT06877637 Protocol version 1 March 2025.

Keywords: Cholangiocarcinoma; Cholangiocellular carcinoma; Hepatocellular carcinoma; Targeted therapy; Tumor evolution; Tumor heterogeneity.

© 2025. The Author(s).

背景： 肝脏和胆道的恶性肿瘤在手术后有较高的复发率，当疾病扩散时预后较差。近年来，医学治疗有所改进，化疗、靶向治疗和检查点抑制剂为影响疾病的进程提供了机会。然而，许多患者并未从这些治疗方法中受益，并且缺乏预测性和预后的生物标志物。BILe duct and LIver 癌症：ON-treatment Surveillance of Tumor evolution And Response to Systemic treatment (BILLIONSTARS) 研究旨在绘制分子肿瘤特征和遗传进化路径如何与治疗反应轨迹相吻合的图谱。

方法： BILLIONSTARS研究是一项前瞻性、单臂观察性研究。斯堪尼亚大学医院马尔默/隆德以及克里斯蒂安斯塔德中央医院诊断为肝细胞癌（HCC）或胆管癌（CCC），并建议进行局部区域干预手术、消融、经动脉化疗栓塞或选择性内放射治疗和/或抗肿瘤药物治疗的患者将被纳入研究。通过临床手段获取的手术或活检组织以及来自尸体解剖的研究样本，将使用靶向深度测序进行评估。根据治疗方法的不同，在不同时间点采集血液样本分析循环肿瘤DNA（ctDNA）和其他相关生物标志物；在手术前或开始系统治疗之前、每次系统治疗之前的疗程之间及治疗结束时。

讨论： HCC和CCC的治疗领域正在发展，从而改善了姑息性护理患者的结局。然而，靶向治疗和检查点抑制的有效性高度可变，并且尚未建立预测生物标志物。疾病的临床过程也具有很高的变异性和不可预测性。通过这项研究，我们希望更深入地了解这些肿瘤的各种生物学特征，包括新的潜在治疗目标以及它们的空间和时间异质性。通过进行全面的尸体解剖研究采样，我们期望进一步扩大对导致终末期疾病分子事件的理解。最终的目标是设计更好的个体化和适应性治疗策略，从而改善HCC或CCC患者的预后。

试验注册： 本研究已在clinicaltrials.gov 注册为 NCT06877637，协议版本 2025年3月。

关键词： 胆管癌；胆管细胞癌；肝细胞癌；靶向治疗；肿瘤进化；肿瘤异质性。

© 2025. The Author(s).