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Scientists break through pancreas cancer treatment barrier
Baku, March 27 (AZERTAC). Pancreas cancer tumors spread quickly and are notoriously resistant to treatment, making them among the deadliest of malignancies. Their resistance to chemotherapy stems in part from a unique biological barrier the tumor builds around itself. Now scientists at Fred Hutchinson Cancer Research Center have found a way to break through that defense, and their research represents a potential breakthrough in the treatment of pancreas cancer.
In a paper to be published in the March 20 issue of Cancer Cell, senior author Sunil Hingorani, M.D., Ph.D., an associate member of the Hutchinson Center's Clinical Research and Public Health Sciences divisions, and colleagues describe the biological mechanisms of how the tumor barrier is formed and detail a newly discovered way to break it down. Their research significantly increased the length of survival in a genetically engineered mouse model of the disease. Early clinical trials in humans are under way at a few sites in the U.S. and Europe, including Seattle Cancer Care Alliance, the Hutchinson Center's patient treatment arm.
Using a mouse model developed by Hingorani, the scientists combined gemcitabine, the current standard chemotherapy used to treat pancreatic ductal adenocarcinomas, with an enzyme called PEGPH20. When they infused the combination into specially engineered mice whose pancreas tumors mimic those of human pancreas cancer, the combination broke down the matrix barrier within the tumors and allowed the chemotherapy to permeate freely and spread throughout the cancerous tissue. The result was a 70 percent increase in survival time of the mice after the start of treatment, from 55 to 92 days.
Unlike most solid tumors, pancreas tumors use a two-pronged defense to keep small molecules, such as those contained in chemotherapy, from entering: a vastly reduced blood supply and the creation of a strong fibroinflammatory response. The latter includes the production of fibroblasts, immune cells and endothelial cells that become embedded within a dense and complex extracellular matrix throughout the tumor. One major component of this matrix is a substance called hyaluronan, or hyaluronic acid (HA). HA is a glycosaminoglycan, a complex sugar that occurs naturally in the body and is secreted at extremely high levels by pancreas cancer cells.
Pancreatic ductal adenocarcinoma is the fourth leading cause of cancer-related death in the United States. Overall five-year survival is less than 5 percent with a median survival of four to six months.
Grants from the National Cancer Institute, the Giles W. and Elise G. Mead Foundation, Safeway and several individuals supported the research. Collaborators from the University of Washington and the Translational Genomics Research Institute in Scottsdale, Ariz., contributed to the study.