TAILORx marks major advance for precision medicine in breast cancer

June 6, 2018|Internal Medicine

REPORTING FROM ASCO 2018

An ongoing companion phase 3 trial, RxPONDER, is assessing the benefit of applying the recurrence score in women who are similar but instead have node-positive disease.

Tailoring treatment: ‘not too much and not too little’

“These are very important data because this is the most common form of breast cancer in the United States and other developed countries, and the most challenging decision we make with these patients is whether or not to recommend adjuvant chemotherapy with all of its side effects and with its potential benefits,” said ASCO Expert Harold Burstein, MD, PhD, FASCO. “The data provided here today from this massive NCI-sponsored trial show that the vast majority of women who have this test performed on their tumor can be told that they don’t need chemotherapy, and that can be said with tremendous confidence and reassurance.”

The recurrence score has been used for a decade, so some may wonder why this trial was necessary. It was important because the score was originally developed in patients given older chemotherapy regimens and older endocrine therapies, and because there have been few data to guide decision making in the large group of patients with midrange scores, he said. “A criticism of the older literature had been, well, chemotherapy didn’t help but that’s because we were using old-fashioned chemo. Now we can say with confidence ... that the patients got contemporary chemo regimens and still saw no benefit from chemotherapy.

“This is not so much about de-escalation ... The goal of this study was not to just use less treatment, the goal was to tailor treatment – they chose the title very aptly, with the idea of saying some women are going to need more of one kind of therapy and less of another, and others will get a different treatment based on the biology of their tumor,” said Dr. Burstein, a medical oncologist at the Dana-Farber Cancer Institute and associate professor of medicine, Harvard Medical School, Boston.