"This shows that these compounds are not toxic to normal breast tissue," Kakarala says. "Women at high risk of breast cancer right now can choose to take the drugs tamoxifen or raloxifene for prevention, but most women won't take these drugs because there is too much toxicity. The concept that dietary compounds can help is attractive, and curcumin and piperine appear to have very low toxicity."

Curcumin and piperine have been explored by other researchers as a potential cancer treatment. But this paper, published online in the journal Breast Cancer Research and Treatment, is the first to suggest these dietary compounds could prevent cancer by targeting stem cells.

In addition, tamoxifen or raloxifene are designed to affect estrogen, which is a factor in most, but not all breast cancers. In fact, the aggressive tumors that tend to occur more often in women with a family history or genetic susceptibility are typically not affected by estrogen. Because curcumin and piperine limit the self renewal of stem cells, they would impact cancers that are not estrogen sensitive as well as those that are.

Researchers are planning an initial Phase I clinical trial to determine what dose of curcumin or piperine can be tolerated in people. The trial is not expected to begin accruing participants until spring.

Breast cancer statistics: 194,280 Americans will be diagnosed with breast cancer this year and 40,610 will die from the disease, according to the American Cancer Society

Source: University of Michigan Health System