Pathological complete response of hepatocellular carcinoma confirmed by conversion hepatectomy following atezolizumab plus bevacizumab therapy: a case report and literature review

The combination regimen of atezolizumab plus bevacizumab (Atezo/Bev) is currently used as first-line treatment in patients with unresectable hepatocellular carcinoma. Herein, we report a rare case of curative hepatic resection performed as conversion surgery in a patient with intermediate-stage hepatocellular carcinoma following preoperative Atezo/Bev therapy. After five treatment cycles of Atezo/Bev therapy, followed by four cycles of atezolizumab monotherapy, the tumor marker levels decreased to baseline levels and 22 small daughter nodules disappeared, leaving only the primary tumor. Therefore, we performed resection of the primary tumor as conversion surgery, and postoperative histopathology confirmed complete tumor necrosis. No cancer recurrence has been observed until the 5-month postoperative follow-up, and the patient remains drug free. Consistent with the findings in this case, a review of previously reported cases revealed that in cases of successful conversion surgery, neoadjuvant Atezo/Bev therapy was associated with intra-tumoral bleeding, immune-related adverse events, and normalization of the tumor marker levels.