Immunoregulatory Effect of Mesima (R) as an Immunotherapeutic Agent in Stage III Gastric Cancer Patients after Radical Gastrectomy

Kim, Jin Pok; Lee, Keon Young; Yu, Hang Jong; Yang, Han Kwang

Abstract

PURPOSE: The effectiveness of adjuvant immunotherapy with Mesima (R) in advanced adenocarcinoma of the stomach was evaluated.
MATERIALS AND METHODS
45 patients with stage III gastric cancer after radical gastrectomy were divided into three groups at random. The first group received Mesima. The second group received OK-432 and the third group received no immunotherapeutic agent at all. All three groups received adjuvant chemotherapy using 5-FU and mitomycin-C protocol. The numbers of total T lymphocytes were checked along with the T4 and T8 subpopulation and B lymphocytes and natural killer (NK) cells preoperatively and 9 days, 3 months and 7 months postoperatively. The delayed-type cutaneous hypersensitivity were also checked preoperatively and 3 months and 7months postoperatively.
RESULTS
All three groups showed initial decrease in the total T lymphocyte count and T4 lymphocyte count at 9 days postoperatively, which showed gradual increase over the 7 months postoperative period. The Mesima (R)-treated group and OK-432-treated group showed significantly better recovery rate at 7 months postoperatively than the control group. The number of T8 lymphocytes and NK cells also showed initial decrease and later recovery, but there was no significant difference between groups. The number of B lymphocytes showed gradual decrease over 7 months in the Mesima (R)-treated group and the control group, and initial decrease with later increase in the OK-432-treated group, again with no significant difference. The average numbers of positive antigens on delayed cutaneous hypersensitivity test were decreased initially with gradual increase, but there was no significant difference between groups.
CONCLUSION
Mesima (R) can be considered as a candidate for safe and effective immunotherapeutic agent in patients with gastric cancer, but the actual benefit in increasing patient survival should be determined through a long term follow-up study.