This announcement from The National Cancer Institute has been very well received but the title could be misinterpreted. Dr. Sparano presented The TAILORx study at the American Society of Clinical Oncology (ASCO) in Chicago in June 2018. This study is a landmark in the sense that it is the largest number of patients with breast cancer ever studied and answers a question that was asked more than a decade ago(2006).
The patients in the study were a confined group with early breast cancer: tumors with hormone receptor positive, HER2 negative and axillary lymph node negative.
The test done in these tumors was a molecular test of 21 genes associated with breast cancer recurrencethat is used routinely in this case, called Oncotype Dx Breast Recurrence Score. The tumors were assigned a score from 0 to 100. They were divided in 3 categories. Low-risk rangesfrom0 to 10, in which patients received antiestrogenic hormone therapy only; the high-risk patients who scored 26 and above received hormonal therapy and chemotherapy; the group in thisstudy was the intermediate range from 11 to 25,who were randomly assigned to either hormone therapy alone or chemotherapy with hormone therapy. The goal was to see ifthe women who receivedhormone therapy alone had as good results as those who also received chemotherapy.
Results: The rates of overall survival were similar for the two groups in the study (83.3 and 84.3%). None of these differences were significant. The researchers also found that the women witha score of 0-10 had very low recurrence rates with hormone therapy alone (3%),and thewomen with ascore of 26-100 had a distant recurrence rate of 13% despite receiving both hormone and chemotherapy. This indicatesthe need for better and more effective therapies for this high risk of recurrence patients.
Furthermore, according to the authors, the findings suggest that chemotherapy may be avoided in 70% of women:
- older than 50 and with a recurrence score of 11-25 (45%)
- any age with recurrence score 0-10 (16%)
- 50 years old or younger with recurrence score of 11-15. (8%)
These findings also suggest that chemotherapy may be considered for the remaining 30% of women:
- any age with a recurrence score of 26-100 (17%)
- 50 years or younger with a recurrence score of 16-25 (14%)
Then, the results demonstrate that chemotherapy is not beneficial for most women in the intermediate risk group, which the design of the trial was to answer this main question. "Any women 75 or younger with early breast cancer (with the characteristics specified above) should have the 21-gene expression test and discuss the results with her doctor to guide her decision to the right therapy," Dr. Sparano said.