The efficacy of cytokine-induced killer cell infusion as an adjuvant therapy for postoperative hepatocellular carcinoma patients.

Background: Even after surgery, hepatocellular carcinoma (HCC) has poor prognosis; adjuvant therapy is needed to improve effectively the outcome of HCC patients. We evaluated the efficacy of cytokine-induced killer (CIK) cell infusion as an adjuvant therapy for postoperative HCC patients.
Methods: A total of 410 patients were studied retrospectively (January 2002 to January 2007): 206 received surgery alone; 204 received surgery and at least four cycles of CIK cell transfusion (CIK group). Kaplan-Meier and Cox regression analyses were used to explore differences in OS between two groups.
Results: The CIK group overall survival rates were significantly higher than that of the surgery-alone group (log-rank test; p = 0.0007). Multivariate survival analysis showed that CIK cell treatment was an independent prognostic factor. In subgroup analysis, patients who received ≥8 cycles of CIK cell transfusion exhibited significantly better survival than the <8 cycle group (p = 0.0272). There was no significant difference in overall survival in patients with ≤5-cm tumors between the CIK and surgery-alone groups (p = 0.7567). However, in patients with >5-cm tumors, the CIK group displayed significantly better overall survival than the surgery-alone group (p = 0.0002).
Conclusions: Postoperative immunotherapy with CIK cell transfusion may be an effective adjuvant treatment for improving the outcomes of HCC patients; >8 cycles of CIK cell transfusion may ensure that patients derive maximal benefits. Moreover, patients with large tumors might benefit more from CIK cell adjuvant treatment than patients with small tumors.