Updates in metastatic and early-stage breast cancer

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Published: 11 Jun 2019
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Dr Harold Burstein - Dana-Farber Cancer Institute, Boston, USA

Dr Harold Burstein speaks to ecancer at the 2019 American Society of Clinical Oncology (ASCO) Annual Meeting about the latest research in breast cancer.

He explains the role of CDK4/6 inhibitors in ER-positive, advanced breast cancer and describes the findings obtained from the MONALEESA-7 trial.

For early-stage patients, Dr Burstein explains the latest findings from the TAYLORx trial, which showed no benefit for chemotherapy.

He also notes the importance of genetic testing and recurrence score testing.

 

There’s a lot of exciting stuff in breast cancer and let me tell you about a couple of stories that I think are very useful. The first is there is a lot of information on the role of anti-oestrogen therapies and targeted drugs in the management of ER positive breast cancer. In the metastatic setting, advanced breast cancer, there are two studies that have looked at this class of drugs called CDK4/6 inhibitors. The first study was called MONALEESA-7, this was a study that looked at younger women, less than age 50 and premenopausal who were put into menopause then started on endocrine therapy and then were randomised to either ribociclib, the CDK4/6 inhibitor, or not. We already knew that ribociclib helped delay the time to progression but what we learned at this meeting was that there is actually a substantial survival benefit for the use of a CDK4/6 inhibitor in patients with ER positive metastatic breast cancer. So that’s a very important finding because there has been a lot of nihilism that you couldn’t actually achieve survival gains in women with ER positive metastatic disease.

A second important study using CDK4/6 inhibitors was the study led by a team of international investigators and they compared endocrine therapy with a different CDK4/6 inhibitor, this time using palbociclib, and they compared that against chemotherapy as the initial treatment for ER positive metastatic disease. Actually they showed that the hormone manipulation plus the palbociclib was better than chemotherapy and that was really a nice study because it had been probably 20-30 years since anyone had compared chemotherapy versus up front hormone therapy for metastatic breast cancer and this is a proof that even in the modern era endocrine therapy still wins.

So those are really important studies for women with ER positive metastatic breast cancer. In women with ER positive early stage breast cancer there are a couple of important updates as well. One of them is updated information from the TAILORx trial which is being reported on Monday and being co-published in The New England Journal of Medicine. What the TAILORx study showed us last year at ASCO in a plenary talk was that for women who had ER positive early stage breast cancer if the Oncotype DX recurrent score was less than 25 overall there was no result that showed benefit for chemotherapy. So the treatment algorithm became very simple – get an Oncotype DX test, if the score is 25 or less for node negative breast cancer there’s no role for chemotherapy.

But there were a couple of small points in there which is that in the young women again, the women less than age 50 who had scores between 16-25, maybe the curves separated and there was a question as to whether or not chemotherapy would be helpful in that group of women. So the update on that trial really shows that there’s no benefit at all for chemotherapy. In fact, what chemotherapy was most likely doing was pushing those women into menopause early and that is a powerful intervention. So women who didn’t go into menopause with the chemotherapy actually didn’t get benefit from chemotherapy and conversely young women, let’s say they’d gone into premature menopause, if they were already in menopause, again, no role for chemotherapy. So that was a really important follow-up study that warranted this major publication in The New England Journal and really helped clarify the role of recurrence score testing in women with early stage breast cancer.