LAUSR

Introduction: Lenvatinib has been approved as a systemic therapy for patients with unresectable hepatocellular carcinoma (HCC). We recently experienced lenvatinib-induced tumor-related hemorrhage in patients with HCC. The full details of tumor-related hemorrhage as a lenvatinib-related adverse event have not been elucidated. Methods: This was a retrospective single-center study that enrolled consecutive patients treated with lenvatinib for unresectable HCC from April 2018 to February 2020. Results: Sixty-eight consecutive patients were enrolled in this study. Among them, 5 cases developed intraperitoneal or intratumoral hemorrhages. The patients with hemorrhage had larger tumors (maximum tumor size, 97.5 ± 46.4 and 38.2 ± 28.8 mm, respectively; p = 0.009) than the patients without hemorrhage. The dosing period of lenvatinib (median, 3 and 93 days, respectively; p < 0.001) and the survival time from initial administration of lenvatinib (median, 77 and 495 days, respectively; p < 0.001) of the patients with hemorrhage were shorter than those of the patients without hemorrhage. Especially, in 4 cases with large HCCs (maximum tumor diameter was >90 mm), tumor hemorrhage with vascular lake-like phenomenon was evident, although most tumor blood flow was suppressed. Discussion/Conclusion: It becomes clear that lenvatinib treatment brings about tumor-related hemorrhages despite rapid suppression of tumor blood flow. We speculate that lenvatinib quickly blocks the feeding circulation, resulting in tumor hemorrhage by necrosis. Clinicians should pay careful attention to the development of life-threatening hemorrhages when treating large HCCs with lenvatinib.