A component of propolis - caffeic acid phenethyl ester, or CAPE - is effective in the cancer's early stages by blocking the ability of cancerous cells to find sources of nutrition.
Although CAPE does not kill cancer, it stops prostate cancer from spreading, and will do so while the patient continues to take propolis, say researchers from the University of Chicago Medicine.
In a test with laboratory mice, the cancer stopped when they were given CAPE for six weeks, and resumed again immediately when treatment stopped.
The mice study followed successful laboratory tests with CAPE on cancer cells.
(Source: Cancer Prevention Research, 2012; 5: 788).