TAILORx: Genomic test helps identify low-risk women who do not need chemotherapy

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Published: 17 Dec 2015
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Dr Virginia Kaklamani - UT Health Science Center, San Antonio, TX

Dr Kaklamani talks to ecancertv at SABCS 2015 about results from the ongoing, prospective Trial Assigning Individualized Options for Treatment (TAILORx) involving more than 10,000 women with estrogen receptor (ER)-positive, HER2-negative, axillary node-negative breast cancer.

TAILORx has been designed to demonstrate whether the Oncotype DX can be used to correctly identify women who may not need chemotherapy and could safely be given endocrine treatment alone.

In the study, patients with a low (<11) Oncotype DX recurrence score (RS) were assigned to endocrine therapy alone and with those with a high (>25) RS assigned to chemoendocrine therapy. Women with an intermediate (11-25) RS were treated with chemoendocrine therapy or endocrine therapy alone and results of that study arm are expected in the future.

Dr Kaklamani discusses the data from the low risk group who received endocrine treatment alone. Five-year rates for distant relapse-free interval, the relapse-free interval, invasive disease free survival, and overall survival were a respective 99.2%, 98.5%, 93.7%, and 98.2%.

The findings show that despite meeting guidelines for recommending or at least considering adjuvant chemotherapy based on classical clinical and pathological features, the risk of recurrence was very low at 5 years. This population of women patients may be very effectively treated with endocrine therapy alone without chemotherapy.

ecancer's filming at SABCS 2015 has been kindly supported by Novartis through the ECMS Foundation. ecancer is editorially independent and there is no influence over content.

May I first ask you about this very interesting study you’ve got looking at a prospective trial of endocrine therapy alone. Now, this is a very big study as well, 10,000 patients. Endocrine therapy alone in patients with ER positive HER2 negative and node negative breast cancer, what were you trying to prove there? What were you putting to the test?

This was a study where we were looking at a genomic test, so a way to look at gene expression in breast cancers. This genomic test is a test that we’ve been using in practice but this is the first study that we’ve done prospectively, so going forward, and looking at whether this test can predict if a patient’s cancer is going to come back and if it’s not.

What did you do in the study?

We took women who had oestrogen receptor positive node negative early stage breast cancer and we performed the Oncotype test, which is the genomic test that was done on this study. Then based on the Oncotype test some women received chemotherapy if they had a high score, and so a high risk of the cancer coming back. Some women did not receive chemotherapy if they had a low score and a low risk of their cancer coming back. Some women that were in the middle got randomised to chemotherapy versus no chemotherapy. The study has not completed yet, this is the first part of the study where we looked at the women that had a low score, so a low risk of their cancer coming back, and the women that did not receive chemotherapy, they only received endocrine therapy. We found that those women had a very, very low risk of their cancer returning.

So how confidently can you go for the chemotherapy sparing approach?

Very confidently after this study.

And what would you say are the clinical implications to doctors?

This is a pretty large group of patients, this is probably around 25-30% of our oestrogen receptor positive patients. So in this group we can avoid chemotherapy altogether.

Wow. You were chairing a news conference just yesterday and in that Dr Nielsen presented on the fact that in some categories of cancer there was no benefit from adjuvant chemotherapy. Do these link together do you think?

They link together and that’s exactly what happened. This Luminal A type of breast cancer which is a more slow-growing oestrogen receptor positive breast cancer really seems to be the same type of cancer that has an Oncotype score that is low. So now you have two studies, one which is a prospective large study which was the TAILORx study and then another study where we looked at tissue from patients that received treatment back a long time ago and we found that those very slow growing tumours, those luminal A or low Oncotype tumours, don’t need chemotherapy.

So different kinds of markers moving in the same direction?

Exactly.

What do you think doctors need to be doing about these new data?

What doctors need to do is to identify the women that have a low risk of recurrence, the women that have these low slow-growing cancers, and not offer chemotherapy to their patients.

And cancer becomes more individualised, cancer therapy?

That’s exactly what it is and that’s really where TAILORx, the name, comes from. You want to tailor your treatment based on the cancer type.

In TAILORx, though, you followed up for five years, was that long enough?

We’re still following patients and this is just the first part of the presentation where we’re looking at the low risk patients. The main reason of TAILORx is to look at the intermediate risk patient population to see if we can avoid chemotherapy in them and that’s another 25-30% of our oestrogen receptor positive early stage breast cancer patients. So if we can avoid chemotherapy in them, you have around 50 or so percent of the oestrogen receptor positive women that don’t need chemotherapy.

So how would you sum up the take home message to doctors, bearing in mind that there are these different risk categories of breast cancer?

Right now the data that we have is for the low risk category, we’re still waiting for the data on the intermediate risk category and that will probably come back in the next couple of years. So we’ll be able to tell them more in the future. But at this point low risk patients, an Oncotype score of ten or less, women do not seem to get a benefit from chemotherapy.