According to a European study of 6,693 breast cancer patients, it is safe to trust genetic testing when it conflicts with results from traditional testing. In some cases, the genetic test may suggest that there is a low risk of the cancer spreading while other tests say the risk is high. The study indicated that in such scenarios, women were just as likely to survive for five years compared to those who had chemotherapy.
This may be partially because traditional tests look for a variety of general factors such as whether a patient is over the age of 50. It is believed that an increased trust in the results of genetic testing could allow up to 35,000 Americans with early breast cancer to avoid chemotherapy. This may prevent unnecessary emotional trauma and keep costs of treatment to reasonable levels.