Impact of the TAILORx Trial on BC Management



Michael D. Alvarado, MD: The TAILORx trial was developed as a prospective trial to look at the genomic assay, the Oncotype DX Breast Recurrence Score, and how well it would do in predicting chemotherapy benefit. Up to the time of the TAILORx data, we were utilizing retrospective-prospective studies, for example, from the NSABP [National Surgical Adjuvant Breast and Bowel Project] B-14 and B-20 data sets. Now, these were very good data that showed that the recurrence score gave us excellent information for patients with a recurrence score of less than 18, for example, or greater than 30.

But there was a question about this intermediate group. Was there actually a benefit or not? And because there was a question for the intermediate group, there were also some questions about the recurrence score around the scores of 16, 17, 18, and the scores of 26, 27, and 28. The developers came up with this idea that we would take women who were estrogen receptor—positive, lymph node–negative, and HER2 [human epidermal growth factor receptor 2]-negative, and we would have them get the Oncotype recurrence score. And then, patients who had a recurrence score of less than 11 would go straight to hormone therapy, but patients who had a score between 11 and 25 would get randomized to either hormone therapy alone or hormone therapy plus chemotherapy.

This trial was really going to show, in a prospective fashion, if women actually benefit from the addition of chemotherapy with a recurrence score between 11 and 25. Now, patients with a higher recurrence score went straight to chemotherapy, so it was specifically for patients with scores between 11 and 25. It took a long time for the TAILORx data to be available because gratefully, all of these women did very well. What it showed is that in that recurrence score range between 11 and 25, there was no benefit with the addition of chemotherapy in these patients.

Now that we have the data from the TAILORx study, it’s really important for patients to understand that the majority of women who have estrogen receptor—positive breast cancers that are node-negative will not benefit from the addition of chemotherapy. It’s extremely important to realize that we can save women from getting these unnecessary treatments that have a significant number of adverse effects. It’s extremely meaningful for women who have lymph node–negative, ER [estrogen receptor]-positive breast cancers in this day and age.

When we see a patient in our clinic who is estrogen receptor—positive and clinically node-negative and HER2-negative, we utilize the genomic assay to get a better idea of what the biology is of that breast cancer. But we also look at some other factors of that patient’s clinical picture to help decide on what the adjuvant therapy should be. If a patient has a low recurrence score, for example less than 25, she likely would be offered endocrine therapy.

But then the question is, should she get tamoxifen? Should she get an aromatase inhibitor? How old is that patient? That is an important decision factor for what type of adjuvant therapy she receives. Even for young women, you might consider ovarian ablation or ovarian suppression based on this recurrence score and the patient’s age. The recurrence score really does help to identify the prediction of chemotherapy benefit, but it can also give you information about how to change or augment your endocrine therapy given the different aspects of what is available for those patients.

The TAILORx data were specifically for women who had a recurrence score between 11 and 25 because these were the women who were randomized to get chemotherapy or not. But this was for all women regardless of age, tumor size, or grade. There were some exploratory analyses that looked at different cohorts of women, for example, those who had different clinical risk: low clinical risk based on tumor size, grade, and patient age; and high clinical risk based on those same parameters. It also specifically looked at age and menopausal status of patients and small cohorts of recurrence scores as well.

These exploratory analyses were used to see if there were any groups of women with these recurrence scores who would potentially benefit from the addition of chemotherapy. Whether you group them by clinical risk score, menopausal status, or smaller recurrence score groups, none of these analyses showed that women would benefit from the addition of chemotherapy. It wasn’t helpful in predicting chemotherapy benefit. However, there was some significant information with regard to prognosis for those patients.

Based on these genomic assays and the recurrence score numbers, adding these clinical risk characteristics definitely provides more information with regard to prognosis. You really can understand, for example, that a woman who has a lower recurrence score is not going to benefit from chemotherapy, but she does potentially have a higher risk of recurrence based on these other clinical characteristics.

That helps the oncologist to understand, is there another endocrine therapy that I could offer this patient because she is at higher risk? Are there any clinical trials that this woman would benefit from if she could undergo these, based on her clinical risk scores? These exploratory analyses really did help identify prognosis characteristics, but they didn’t show that there was any predictive capability when added to the genomic assay.

Transcript Edited for Clarity

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