The harms and benefits of adoptive immunotherapy (AIT) for patients with postoperative hepatocellular carcinoma (HCC) are controversial among studies. This study aims to update the current evidence on efficacy and safety of AIT for patients with HCC who have received curative therapy. Electronic databases were systematically searched to identify randomized controlled trials (RCTs) and cohort studies evaluating adjuvant AIT for patients with HCC after curative therapies. Recurrence and mortality were compared between patients with or without adjuvant AIT. Eight RCTs and two cohort studies involving 2,120 patients met the eligibility criteria and were meta-analyzed. Adjuvant AIT was associated with significantly lower recurrence rate than curative therapies alone at 1 year [risk ratio (RR) 0.64, 95%CI 0.49-0.82], 3 years (RR 0.85, 95%CI 0.79-0.91) and 5 years (RR 0.90, 95%CI 0.85-0.95). Similarly, adjuvant AIT was associated with significantly lower mortality at 1 year (RR 0.64, 95%CI 0.52-0.79), 3 years (RR 0.73, 95%CI 0.65-0.81) and 5 years (RR 0.86, 95%CI 0.79-0.94). Short-term outcomes were confirmed in sensitivity analyses based on RCTs or choice of a fixed- or random-effect meta-analysis model. None of the included patients experienced grade 3 or 4 adverse events. Therefore, this update reinforces the evidence that adjuvant AIT after curative treatment for HCC lowers risk of recurrence and mortality.
Keywords: adjuvant; adoptive immunotherapy; hepatocellular carcinoma; meta-analysis.