Lentinan prolonged survival in patients with gastric cancer receiving S-1-based chemotherapy.

Aim: To examine whether administration of lentinan, purified β-1, 3-glucan, can prolong survival in advanced gastric cancer patients receiving S-1-based chemotherapy.

Methods: Since 2004, 78 patients with metastatic or recurrent gastric cancer have received S-1-based chemotherapy as first-line treatment. Survival, side effects, and the ratio of granulocytes/lymphocytes (G/L ratio) were compared between 2 groups of patients who received chemo-immunotherapy using lentinan and chemotherapy alone.

Results: Median overall survival was significantly longer in the former group than in the latter group [689 d (95% CI: 431-2339 d) vs 565 d (95% CI: 323-662 d), P = 0.0406]. In addition, the G/L ratio in patients who received lentinan was maintained around or below 2, which was significantly lower than that in patients who received chemotherapy alone (P < 0.001).

Conclusion: Chemo-immunotherapy with lentinan offers a significant advantage over S-1-based chemotherapy alone in terms of survival in patients with advanced gastric cancer.