Lentinan as an immunotherapeutic for treating lung cancer: a review of 12 years clinical studies in China

Purpose Lentinan is a polysaccharide extracted from Shiitake mushrooms that have been used to improve general health for thousands of years in Asia. Lentinan injection is a clinically approved drug in several countries in Asia. The purpose of this study is to review the structure, preclinical and clinical studies, and molecular mechanisms of lentinan. Most importantly, the clinical effectiveness of lentinan as an adjuvant therapeutic drug in treating patients with lung cancer in China during the past 12 years is analyzed statistically. Methods We carried out literature search of randomized controlled trials (RCTs) published from 2004 to 2016 based on CNKI (China National Knowledge Infrastructure), VIP (Chongqing VIP Chinese Scientific Journals Database) and Wanfang database, and 38 eligible RCTs of lentinan-associated lung cancer treatment were identified, containing 3,117 patients. Results The structure and function relationship and underlying molecular mechanism of lentinan as an immunostimulant has been summarized. The mean value of overall response rate in treating lung cancer was increased from 43.3% of chemotherapy alone to 56.9% of lentinan plus chemotherapy [ p < 0.001, 95% confidence interval (CI) 0.102–0.170]. Compared with chemotherapy alone, lentinan plus chemotherapy showed more efficacy in treating lung cancer (pooled RR 0.79, 95% CI 0.74–0.85) and no statistical heterogeneity was found among studies ( I 2 = 11%). Conclusion Clinical data presented in the past 12 years shows that lentinan is effective not only in improving quality of life, but also in promoting the efficacy of chemotherapy during lung cancer treatment.