Retrospective analysis of the efficacy of adjuvant CIK cell therapy in epithelial ovarian cancer patients who received postoperative chemotherapy

Cytokine-induced killer (CIK) cells are demonstrated to possess potent cytolytic effect against ovarian cancer cells in vitro and in vivo. However, the clinical efficacy of maintenance therapy of CIK cells in patients with epithelial ovarian cancer (EOC) after first-line treatment remains unclear. This retrospective study included 646 cases of postoperative EOC patients, 72 of which received chemotherapy and sequential immunotherapy (CIT group), and 574 of which received only chemotherapy (Control group). Patients in the CIT group received at least four cycles of CIK cell (range 8.0 × 10(9) – 1.3 × 10(10) cells) transfusion, with the interval of each cycle being 2 weeks. Survival analysis showed a significantly higher overall survival (OS) rate in the CIT group compared with the control group, as well as a favorable progression-free survival (PFS). Univariate and multivariate analyses indicated that adjuvant CIT was an independent prognostic factor for the OS of patients with EOC. Furthermore, subgroup analyses showed that adjuvant CIT significantly improved the OS of patients older than 45 years, with CA125 ≤ 1000, or with moderate or poorly differentiated tumors, and prolonged the PFS of patients with residual disease > 1 cm. Additionally, Kaplan-Meier analyses revealed that a higher fraction of CD3(+)CD8(+)/CD3(+)CD56(+) phenotypes or lower percentage of CD3(+)CD4(+)/CD3(−)CD56(+) phenotypes in the infused CIK cells significantly associated with better survival of patients with EOC. Furthermore, across all processes of CIK cell immunotherapy in the CIT group, 12.5% (9/72) of patients developed self-limiting light fevers and shivering at grade 1 or 2. No immunotherapy-related serious reactions were recorded. These data indicate that adjuvant CIT with CIK cells is an effective therapeutic approach to prolonging the survival of EOC patients.