|
|
|
|
|
|
out of two hundred that were originally screened by Japanese researchers for antitumor activity in 1971. |
|
|
|
|
|
|
|
|
Probably the most impressive demonstration of PSK's antitumor function came in 1990, when the results of a ten-year Japanese clinical trial involving colon or gastric cancer patients were announced. In this study, fifty-six patients began taking PSK daily after having undergone surgery for cancer of the colon and rectum. Over a period of thirteen years, the patients returned to the administering clinic (six hospitals were involved) about once every three months for evaluation. The survival rate of these patients was significantly higher than that of the fifty-five patients in the placebo group.
120,121 |
|
|
|
|
|
|
|
|
The exact mechansim of Coriolus extract is unclear. Most likely, its effectiveness is due to an overall activation of the immune system. One thing that is known is that Coriolus stimulates both T-killer lymphocytes and macrophages, which are the primary white blood cells responsible for dissolving tumors. It stimulates not only the number of macrophages but the motility of macrophages to the tumor, and at the same time inhibits the tumor cell's motility. It has also been shown to have a beneficial effect on overall T-cell count enhancement and it stimulates spleen and thymic activity. |
|
|
|
|
|
|
|
|
One Japanese study focused on the effects of PSK once the progression of carcinogenesis had begun. The study demonstrated that PSK influences the steps of cancer metastasis in a number of ways: |
|
|
|
|
|
|
|
|
By inhibiting tumor invasion, adhesion, and production of cell matrixdegrading enzymes. |
|
|
|
|
|
|
|
|
By suppressing tumor-cell attachment to endothelial cells through the inhibition of tumor-cell-induced platelet aggregation. |
|
|
|
|
|
|
|
|
By suppressing tumor-cell migration through the inhibition of tumor cell motility. |
|
|
|
|
|
|
|
|
By suppressing tumor growth through the inhibition of angiogenesis.122 |
|
|
|
|
|
|
|
|
A recent five-year study of gastric cancer patients reported that PSK was the therapeutic agent responsible for significant improvements in their condition. Studies done by the Japanese government over a period of thirteen years agree with these findings and support evidence that PSK (which is an approved drug in Japan) increases long-term survival and decreases the rate of cancer recurrence.123 PSK, taken as an adjuvant following surgery for colon cancer, was |
|
|
|
|
|