Welcome back to an introduction to breast cancer. I'm Dr. Anees Chagpar. I just returned from the American Society of Clinical Oncology meeting in Chicago this year, and I wanted to share with you some updates. Because they really impact what we've been talking about in this course. Now, many of you will remember, from the last time I gave you an update earlier this year, that the staging system had changed. So we moved from the AJCC seventh edition, to the eighth edition. One of the important things that happened in that transition was the inclusion of genomic tests. So, now instead of focusing just on how big the tumor is, are the lymph nodes involved or not and how many and is this spread to any other place in the body, are classic TNM staging system. The new staging system now incorporates a lot of additional information. It incorporates for example, grade, hormone receptor status, whether the tumor is her2 positive or negative and it's including some genomic tests. You'll remember from our earlier lecture that these genomic tests tell us whether certain genes are turned on or turned off and can give us an idea about prognosis, how well people are willing to do. So, hopefully this slide looks familiar, and we talked about the fact that for hormone receptor positive her2 negative, node negative tumors, regardless of tumor size if you have a low recurrence score, less than 11 or you have a low risk score on Mammaprint or Endopredict or even Breast Cancer Index, kind of a low recurrence score for PAM50. For all of these staging systems, you're now going to be classified as stage one. Even though in the anatomic staging system, if you had a larger tumor, you may have been classified as a higher stage. So, this really highlighted the fact that we're now putting a lot of emphasis on tumor biology. Well, then I wanted to talk to you a little bit more about all of this tumor biologic information that we have. Now, if you go back and review the medical oncology literature and our discussion from that lecture, this slide will look familiar as well. We talked about these genomic tests and this is just an example of one, called Oncotype Dx. Where you can see that this is a 21-gene assay looking at a variety of factors. Proliferation factors, whether the tumor has invaded, her2 positivity, estrogen receptor, and so on. Well, the Oncotype Dx is often helpful to do two main things. One is to predict the 10-year distant disease free survival rate and the other is to predict whether patients will respond better to endocrine therapy. That is to say, therapy that is geared against blocking hormone receptors like estrogen receptor or progesterone receptor. Or whether patients really will do better with the addition of chemotherapy. In lecture we said for low recurrence scores, people really did very well with endocrine therapy alone. That is to say, taking a pill that would block estrogen or progesterone receptor. However, for patients who are at higher recurrence scores, they do better with the addition of chemotherapy. Now, this test was really validated for patients who were endocrine receptor positive. So, ER positive Or PR positive and node negative. We now have validated it in the node positive setting as well. But, what this really left was this middle ground. So, we knew that the low risk score, people who really were having a score of say zero to ten benefited from endocrine therapy alone. They really didn't need chemotherapy regardless of how big the tumor was, especially if they were node negative. The high risk group, those who had a score of 26 to 100, benefited from the addition of chemotherapy. But there's a blank space in between there. What do we do about this intermediate risk group? Those who have a score of between 11 and 25. Well, the jury was really out on these patients until now. So, the TAILORx Trial which was reported just recently at Chicago at the ASCO breast cancer session, randomized patients to either receive endocrine therapy or chemotherapy plus endocrine therapy and they wanted to see which group did better. Well, they had 10,273 women, all of whom had hormone receptor positive her2 negative, lymph node negative breast cancer and of those, about two-thirds. So 6,700 fell in that intermediate range. So, had recurrent scores of somewhere between 11 and 25. Now, they followed these women for seven and a half years. Remember, half got chemotherapy plus endocrine therapy and half got endocrine therapy alone. What you can see is that the nine year disease-free survival rate, the distant recurrence rate, the overall survival rate, was about the same in both groups which led researchers to believe that the addition of chemotherapy for the majority of patients who fall into this intermediate category, with scores between 11 and 25 don't really benefit from the addition of chemotherapy over endocrine therapy alone. Now, there is one curve yard. They did find that chemotherapy was of benefit in younger women. So, those under the age of 50, who had a slightly higher recurrence score. So, a recurrence score of 16 to 25. Now, this hit the media and so you may have heard headlines like chemotherapy no longer recommended for all women with breast cancer. Now you know the data behind it and some of the nuances. It really depends on the recurrent score and your age. So, if patients fall in this intermediate range and they're older than age 50, they really have no benefit with the addition of chemotherapy. But, if you have a higher recurrent score, over 25, you do benefit from chemotherapy. If you're under the age of 50 and your recurrent score is 16 to 25 or higher, you still benefit from chemotherapy. But everybody who has a recurrent score under the age- under 16, will benefit from endocrine therapy alone. So, hopefully that clarifies things. I just was really excited to bring you another update as I receive it. I hope you're enjoying this course. Please do keep in touch with us. I love getting your tweets and hearing you on the discussion boards. Until next time, this is Dr. Anees Chagpar.
