Assessment of Macrovascular Invasion in Advanced Hepatocellular Carcinoma: Clinical Implications and Treatment Outcomes with Systemic Therapy

Introduction: Macrovascular invasion (MVI) is a strong prognostic factor for advanced hepatocellular carcinoma (HCC). The current criteria for radiological assessment are unclear in evaluating the impact of MVI on systemic therapy. In this study, we standardized the assessment of MVI and validated its clinical relevance. Methods: Clinical data were collected from patients with advanced HCC and MVI who received first-line systemic therapy at four medical centers in Japan. First, we used MVI progressive disease (MVI-PD) to track MVI progression and Response Evaluation Criteria in Solid Tumors version 1.1 progressive disease (RECIST v1.1-PD) to evaluate tumor enlargement other than MVI and the appearance of new lesions. Next, we assessed the prognostic value of MVI-PD and RECIST v1.1-PD. Results: Of the 207 advanced HCC patients with MVI, 189 received appropriate imaging evaluation. Forty (21.2%) patients had MVI-PD and RECIST v1.1-PD, 51 (27.0%) had prior MVI-PD, and 61 (32.3%) had prior RECIST v1.1-PD. In a landmark analysis, the prognosis of 163 patients who survived more than 3 months was analyzed based on the assessment of imaging response during the first 3 months. The median overall survival (OS) was 5.4 months in those who had MVI-PD and RECIST v1.1-PD, 7.4 months in those who had RECIST v1.1-PD only, 7.2 months in those who had MVI-PD only, and 19.7 months in patients who had neither (p < 0.001). The correlation coefficients between progression-free survival and OS in patients with appropriate imaging assessments were similar for MVI-PD (0.515) and RECIST v1.1-PD (0.498). Conclusion: Our findings demonstrate the link between MVI progression and poor OS in systemic therapy for advanced HCC, emphasizing the importance of an accurate method for assessing MVI progression.