Pathological Complete Response and Successful Conversion Hepatectomy in Initially Unresectable Giant Hepatocellular Carcinoma Following Triple Therapy With HAIC , Bevacizumab, and Tislelizumab: A Cas

ABSTRACT

Severe future liver remnant (FLR) deficiency frequently renders giant hepatocellular carcinoma (HCC) unresectable. We report a 48‐year‐old man with an unresectable 23.5‐cm giant HCC (Couinaud segments 4/5/8; baseline serum alpha‐fetoprotein (AFP), 1036.65 μg/L). Initially requiring an extended right trisectionectomy with an FLR/standard liver volume (SLV) ratio of only 36.58% (450 mL). Following three cycles of mFOLFOX‐HAIC, bevacizumab, and tislelizumab, restaging computed tomography (CT) showed tumor regression to 9.0 cm in maximum diameter (a 61.7% reduction), corresponding to a partial response (PR) according to the Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST 1.1), and a complete response (CR) according to the modified RECIST (mRECIST), an increase in FLR volume to 733 mL (FLR/SLV: 59.58%), and an AFP decline to 115.00 μg/L. Crucially, tumor clearance from segment 4 and separation from the right portal pedicle enabled surgical downstaging to a parenchymal‐sparing anatomical right anterior sectionectomy (S5/8). R0 resection was achieved, with histopathology confirming a pathological complete response (pCR; 100% coagulative necrosis). Postoperatively, serum AFP normalized to 5.60 μg/L, and the patient remains recurrence‐free at 22 months. This case illustrates that tumor regression during triple therapy may be accompanied by increased FLR volume and improved anatomical separation from the right portal pedicle, potentially enabling a more limited resection without portal vein embolization.