Downstaging in hepatocellular carcinoma (HCC) aims to convert patients with initially unresectable or transplant-ineligible tumors into candidates for curative therapy, such as liver resection or transplantation. Traditionally, this has been achieved with locoregional therapies such as TACE, radioembolization, or ablation. The major new development is the use of immuno-oncological treatments, especially immune checkpoint inhibitor–based combinations.
Combinations such as atezolizumab–bevacizumab and durvalumab–tremelimumab can produce meaningful tumor responses in advanced or borderline HCC, creating opportunities for conversion surgery or downstaging into transplant criteria. Updated HCC guidance recognizes that patients who achieve successful downsizing or downstaging after treatment may be reconsidered for resection or transplantation.
For surgery, immunotherapy-based downstaging is promising because tumor shrinkage, vascular response, and improved disease control may allow resection in selected patients with preserved liver function. However, careful assessment of residual liver reserve, portal hypertension, and radiological response remains essential.
For transplantation, the situation is more complex. Pre-transplant immune checkpoint inhibitors may help downstage HCC, but they also carry a risk of post-transplant acute rejection, including graft loss. Therefore, transplant use requires strict selection, multidisciplinary discussion, and adequate washout before surgery.
Key Message:
Immuno-oncological therapy is expanding the boundaries of curative HCC treatment by enabling downstaging for surgery and transplantation, but in transplant candidates, the benefit must be balanced against the serious risk of immune-mediated graft rejection.