Pancreatic cancer is a highly malignant gastro-intestinal (GI) cancer, which has a very poor prognosis. Both diagnosis and treatment of pancreatic cancer are difficult. Almost 90% of pancreatic cancer is ductal adenocarcinoma derived from glandular epithelium. In recent years, the morbidity and mortality of pancreatic cancer is increasing significantly with the five-year survival rate being <1%. It is one of the malignant tumors having the worst prognosis. Pancreatic cancer has low early diagnosis rate, high surgical mortality, and low cure rate. In recent years, the morbidity and mortality of other cancers are also increasing continuously.
The key to treatment of cancers, especially the pancreatic cancer, is to seek for an effective anti-tumor agent, which is also a focus of recent studies.
Since the 1970s, researchers have paid increasing attention to algae, especially blue-green algae. At first, the researchers mainly focused on the nutrition value and virulence of algae. In the meeting of the United Nations food and agriculture organization in 1974, spirulina was considered to be an excellent food resource for people in the future. Pharmaceutical uses of algae have been appreciated since the 1980s, and the research was mainly focused on the function of various algal extracts. The research on blue-green algae extract, especially the spirulina extract was particularly striking. The inventors in this application extracted an algal proteoglycan extract from the algae (see, the Chinese Patent CN1098707C). In the present application, the inventors studied the therapeutical effect of the algal proteoglycan extract on cancers (especially pancreatic cancer), as well as on pain (such as pain associated with tumors) and inflammation (such as inflammation associated with tumors).