THE TAILORx CLINICAL TRIAL

Reducing Treatment and Side Effects

TAILORx was the largest ever adjuvant breast cancer treatment clinical trial, which showed that when guided by a diagnostic test, some women with the most common type of breast cancer may no longer need to have chemotherapy to increase their chance of survival.

The study found that for some women with hormone receptor (HR) positive, HER2 negative, axillary lymph node-negative breast cancer, treatment with chemotherapy and hormone therapy after surgery is no more beneficial than treatment with hormone therapy alone.

A genetic test called Oncotype DX or 21-gene assay may identify up to 70% of women with early stage HR positive HER2 negative breast cancer, which has not spread to the lymph nodes, who can be spared chemotherapy and the side effects of this treatment, especially those who are older than 50 years of age.

The findings suggested that chemotherapy may be spared in:

• Women older than 50 years with hormone receptor–positive, HER2-negative, node-negative breast cancer and a Recurrence Score of 0 to 25 (about 85% of women with breast cancer in this age group);
• Women 50 years or younger with hormone receptor–positive, HER2-negative, node-negative breast cancer and a Recurrence Score of 0 to 15 (about 40% of women with breast cancer in this age group).

The study involved 10,273 patients worldwide, including 25 women from Australia and New Zealand.