Many patients that develop cancerous breast tumors have tumors that are sensitive to the hormone estrogen. In these tumors, estrogen contributes to growth. A class of drugs called aromatase inhibitors are often prescribed, because these drugs can lower the amount of estrogen in the body and, thereby, help block the growth of these tumors.
Unfortunately, there are subsets of women that have to discontinue this pharmacological therapy because they develop severe arthritis when taking aromatase inhibitors as a treatment for breast cancer.
As reported on September 27, 2010, scientists at the Mayo Clinic in Minnesota, as well as their colleagues in Canada, Japan and other parts of the United States, studied this medication ???problem??? in cancer patients, focusing on single nucleotide polymorphisms (SNPs) which are gene variants. Their research results have led to the discovery of genetic variants that are involved in the development of arthritis.
The patients selected for this study were enrolled in clinical trials that compared the effects of two specific aromatase inhibitor drugs on breast cancer. Control subjects were matched to each patient enrolled in the clinical trial.
Researchers noted that many patients had dropped out of the clinical trial because of the pain associated with arthritis that developed over the course of the study. Further inspection of the patients that withdrew from the clinical trial revealed four SNP on chromosome 14 that were of interest. Each one of the SNPs were near the T-Cell Leukemia 1A gene, and further study of this gene revealed that it was an estrogen-dependent gene. One of the four SNPs also displayed what the researchers described as an estrogen response after being exposed to estradiol (an estrogen).
The results of this study provide researchers with tools (genetic markers) that can help identify patients that may develop this form of arthritis when treated with aromatase inhibitors for cancer.
Tags: Aromatase Inhibitors, breast cancer, Mayo Clinic