Background: Interleukin (IL)-12 is a heterodimeric cytokine that exhibits potent antitumor and antimetastatic activities. Very few studies have so far investigated the local expression of L-12 in tumor specimens of gastric cancer. The purpose of this study was to investigate the immunohistochemical expression of IL-12 in patients with gastric cancer.
Patients and methods: IL-12 was immunohistochemically stained using monoclonal antihuman IL-12 antibody (1-1A4) in surgical specimens of 117 gastric cancer patients. The IL-12-positive cell density was calculated. The relationships among the IL-12-positive cell density, clinicopathological factors and 5-year survival rate were evaluated.
Results: Among the patients (n=117), the 5-year survival rate after surgery was not statistically different between the patients with high and low IL-12 positive cell-density. However, in the patients with advanced gastric cancer (n=85), those with a high IL-12-positive cell density showed a significantly better prognosis in comparison with those with a low IL-12-positive cell density (p=0.0104). A multivariate analysis indicated that the IL-12-positive cell density and TNM stage are significant prognostic factors.
Conclusion: IL-12-positive cell density may be a significant independent prognostic factor in surgical specimens of advanced gastric cancer.