Is stem cell therapy available for cancer?
Not yet. Cancer stem cells must be destroyed, or recurrence is nearly certain. While chemo and radiation don’t kill them, there are natural therapies that do. Now, some stem-cell therapy are promising for cancer patients. Again, we know there are cancer stem cells, and some researchers believe the key to a cancer cure relates to inhibiting their proliferation.
Think about this: if tumors can’t sustain growth without cancer stem cells— in fact, tumors cannot survive without them—then we should develop target-specific therapies to destroy them. This is the new hope for improving survival and quality of life for cancer patients, especially those with advanced disease. For years some researchers have proposed that the reason for chemo’s failure, for its inordinate recurrence rate, is that even though it effectively kills the bulk of a tumor’s malignant cells to the point of remission, chemo/radiation-resistant cancer stem cells go untouched, ready for a new beginning.
What’s more, it would be less toxic, and theoretically more effective, to target treatments directly at the small population of cancer stem cells instead of trying to kill all the billions of cells in a tumor. Eliminating the stem cells would ultimately kill the cancer and halt metastasis. Therefore a number of US and European pharmaceutical labs have developed drugs to selectively target cancer stem cells and are in early clinical phase trials. Results are somewhat encouraging but also are mixed, still far from being FDA-approved, and likely to be very expensive.
While we wait for wonder drugs, there’s an alternative for directly and selectively attacking cancer stem cells. Incredibly, this option comes from observational studies of diabetes, a chronic disease correlated with increased risk of breast and other cancers. Metformin, extensively used for treating diabetes, obesity, and polycystic ovarian syndrome, also has been shown to inhibit growth of breast cancer cell lines and tumor growth of aggressive cancers. Dr. Heather Hirsch and colleagues said “the combination of metformin with existing chemotherapeutic drugs, which attack non-stem cancer cells, was shown to have a dramatic effect on reducing tumor mass and prolonging tumor remission.”
Since diabetic patients with ovarian cancer taking metformin have better outcomes than those not taking it, the Al-Hajj group designed a study to evaluate metformin’s impact in ovarian cancer stem cells. Dr. Jessica Shank reported that metformin significantly restricted the growth of those cell lines in vitro and inhibited formation of cancer stem cells from patient tumors. They also combined metformin with chemotherapy and found it to restrict tumor growth due to a decrease in cancer stem cell population, malignant bulk cell proliferation, and angiogenesis.
Because of the demonstrations that metformin can greatly improve patient outcomes with direct and selective killing effects on cancer stem cells, patients at Oasis of Hope have been receiving it since 2007 as a part of our comprehensive and integrative anti-cancer approach.