Tamoxifen, one of the most prescribed drugs for breast cancer has always produced complaints of a "mental fog" from patients taking the medication. In a Sept. 17 announcement, the University of Rochester Medical Center revealed that its researchers had confirmed the existence of "mental fog", and have found a medication that may counter the side effect. In addition, selumetinib, the countering medication, may enhance the effectiveness of tamoxifen in breast cancer treatment.
Tamoxifen is one of several drugs used to treat hormone receptor-positive breast cancer. It mimics estrogen and blocks that hormone's ability to stimulate tumor growth, according to the National Cancer Institute. The drug has been used for three decades and has a proven track record but does come with side effects, including reports of slowed cognitive functions.
The U of R study verified the patient complaints, and then examined over 1,000 compounds to determine if any would relieve the problem. The study's authors found that a substance identified as AZD6244, known as selumetinib, was effective in mice in stopping the toxic effects of tamoxifen on brain cells. The press release further notes that
the experiments in his laboratory agreed with studies by other research groups, who found that the combined use of AZD6244 and chemotherapy enhances targeting of cancer cells.
The researchers at the University of Rochester will continue to pursue this avenue of inquiry. Future research will examine dosage levels for the two drug combination that provide the maximum treatment for cancer and the minimum effect on brain cells.