Mushroom polysaccharide lentinan for treating different types of cancers: A review of 12 years clinical studies in China.

Lentinula edodes has been used to improve general health for thousands of years in Asia. It is the second largest cultivated and the most popular edible mushroom in the world known as "Xianggu" in China and "Shiitake" in Japan. Lentinan is a polysaccharide extracted from Lentinula edodes. β-Glucan is the major bioactive component in lentinan with immunostimulatory effect. The antitumor property of lentinan was reported in 1960s. Biochemical studies indicate that immunocytes can be activated by lentinan through multiple signaling pathways, such as TLR4/Dectin1-MAPK and Syk-PKC-NFκB pathways. Though it has been approved as an adjuvant therapeutic drug both in China and Japan for treating cancers since 1980s, a systematic review of clinical studies of lentinan has not been conducted elaborately. In this review, over 9474 reported lentinan-associated cancer treatment cases are evaluated and summarized from 135 independent studies in China during the past 12 years (2004-2016) based on CNKI (China National Knowledge Infrastructure), VIP (Chongqing VIP Chinese Scientific Journals Database) and Wanfang database. The 9474 reported lentinan-associated cancer treatment cases include lung cancer (3469 cases), gastric cancer (3039 cases), colorectal cancer (1646 cases), ovarian cancer (183 cases), cervical cancer (130 cases), Non-Hodgkin lymphoma (70 cases), pancreatic cancer (15 cases), cardiac cancer (15 cases), nasopharyngeal cancer (14 cases), duodenal cancer (1 case) and 110 cancer cases with no classifying patient information. Overall clinical data show solid effect of lentinan on improving the quality of life and on promoting the efficacy of chemotherapy and radiation therapy during cancer treatment.