A team at University of Texas (UT)'s Health Science Centre has already explored the use of extract from the Amur cork tree's bark in treating prostate cancer.
Researchers found that deadly pancreatic cancers share some similar development pathways with prostate tumours.
They show that the extract blocks those pathways and inhibits the scarring that thwarts anti-cancer drugs.
"Fibrosis is a process of uncontrolled scarring around the tumour gland," said A Pratap Kumar, the study's principal investigator.
"Once you have fibrotic tissue, the drugs cannot get into the cancer," said Kumar.
Liver and kidney tumours also develop fibrosis and the resulting resistance to drugs, he said, and there are no drugs currently targeting that pathway in those cancers.
The two pathways, or proteins, that contribute to fibrosis in those tumours also encourage Cox-2, an enzyme that causes inflammation, and the cork tree extract appears to suppress that as well, Kumar said.
The complex interrelationship of these substances is "the million-dollar question," he said.
The potential of natural substances to treat and cure disease has great appeal, but the advantage of cork tree extract, available as a dietary supplement in capsule form, is that it already has been established as safe for use in patients, researchers said.
In a promising prostate cancer clinical study of 24 patients that Kumar helped spearhead, all the patients tolerated the treatment well, he said. The study was published in the journal Clinical Cancer Research.