Vitamin D could hold a clue to more effective breast cancer treatment. That's the suggestion put forward by a group of Dartmouth researchers in a report in the June issue of the Journal of Clinical Cancer Research. The study, which involved the treatment of breast cancer tumors in mice, adds to a growing body of evidence that a derivative of vitamin D known as EB1089 may yield some powerful anti-cancer properties, particularly when combined with radiation therapy.
When compared to other cancer treatments, the vitamin D analog is much less toxic and, at least preliminarily, it appears to aid radiation therapy in impacting the growth of tumor cells. An analog is a synthetic, laboratory-made derivative of a parent compound -- in this case vitamin D -- that is genetically engineered by adding or removing certain chemical elements. In the instance of EB1089, it was necessary to modify vitamin D because "at the dose you need to give to have an effect on cancer, it could cause some side effects," Sundaram says. Those side effects would include an overload of calcium, a condition known as hypercalcaemia.
Adding the vitamin D to the treatment regimen is thought to enhance the ability of the radiation to bring about apoptosis -- or cell death. It also reduces the proliferation, or growth of cancer cells, in the tumor itself. While the finding in this particular study is unique, previous research on vitamin D found it was effective against both prostate and breast tumors. Currently, a large European trial is testing EB1089 on human cancer patients.