The TS gene regularly comes in two forms, or polymorphisms. In the other form, the string repeats itself three times. Each person has a set of two TS genes. In total, three combinations are possible. The researchers found that patients who had a pair of genes that were both double repeaters responded best to Xeloda.
Response means that tumors shrank by half or more.
The cells in these patients expressed fewer signals to produce TS, Dr. Lenz explains. Using knowledge about each patient s genetic makeup, physicians in the future may be able to recommend alternate medicines that work differently to patients who would not likely respond to Xeloda, Dr. Lenz says. The five-year survival rate for patients with advanced or metastatic disease is less than 10 percent. Any question regarding a medical diagnosis, treatment, referral, drug availability or pricing should be directed to either a licensed physician or to the product's manufacturer.