Personalized medicine: the time is now; six years after scientists successfully sequenced the entire human genome, the results are changing nearly every aspect of medicine.(AGES & STAGES)

"There have been some spectacular successes with genetic information that are beginning to have a significant impact on the care and treatment of patients today," says Geoffrey S. Ginsburg, MD, PhD, who directs the Center for Genomic Medicine in the Duke Institute for Genome Sciences & Policy in Durham, NC.

One of the most significant areas affected is cancer treatment. "The ability to evaluate cancer patients on the basis of the molecular fingerprint of their cancer is readily available today," Dr. Ginsburg said. That information is then used to more effectively target treatments, many of which are so expensive that some insurers actually require genetic testing before approving their use.

Some of the greatest impact of personalized medicine for women can be seen in breast cancer. Today, pathologists identify the genetic makeup of the tumor, the results of which help the oncologist determine treatment. For instance, a genetic test called Oncotype DX rates the likelihood of recurrence. If the odds are small, the oncologist may not recommend chemotherapy or radiation. (24)

Conversely, if the tumor tests positive for the HER2 protein, which is produced by the HER2 gene and causes cancer cells to grow faster, you know you have a more aggressive cancer and are a candidate for trastuzumab (Herceptin). If your tumor expresses estrogen, then you are a candidate for the antiestrogen treatment tamoxifen. However, before giving you the drug, your doctor might test for genetic changes in your CYP2D6 gene. This gene makes an enzyme called 2D6, required to transform tamoxifen into the cancer-attacking antiestrogen endoxifen. But a mutation in the CYP2D6 gene can render those enzymes inactive or only moderately active, making tamoxifen fairly worthless. (25)

The area of pharmacogenetics--or selecting drugs on the basis of the genetic underpinnings of the disease or the ...