Role of Patient and Disease Factors in Adjuvant Systemic Therapy Decision-Making for Early-Stage, Operable Breast Cancer Update

An interview with Dr. Lynn Henry from University of Utah Huntsman Cancer Institute on "Role of Patient and Disease Factors in Adjuvant Systemic Therapy Decision-Making for Early-Stage, Operable Breast Cancer: Update of the ASCO Endorsement of CCO Guideline." This guideline update includes data from the MINDACT and TAILORx trials to clarify the recommendations for patients with hormone receptor-positive, HER2 not overexpressed, axillary node-negative early breast cancer.

Read the full guideline at www.asco.org/breast-cancer-guidelines

TRANSCRIPT

The purpose of this podcast is to educate and to inform. This is not a substitute for professional medical care and is not intended for use in the diagnosis or treatment of individual conditions. Guests on this podcast express their own opinions, experience, and conclusions. The mention of any product, service, organization, activity, or therapy should not be construed as an ASCO endorsement. Hello and welcome to the ASCO Guidelines Podcast Series. My name is Shannon McKernin. And today, I'm interviewing Dr. Lynn Henry from the University of Utah Huntsman Cancer Institute, lead author on "Role of Patient and Disease Factors in Adjuvant Systemic Therapy Decision-Making for Early-Stage, Operable Breast Cancer: Update of the ASCO Endorsement of CCO Guideline." Thank you for being here today, Dr. Henry. Thank you very much for the invitation. So this guideline was updated to incorporate new data from the TAILORx and the MINDACT trials. So can you give us an overview of these trials and their results? Sure. So patients with hormone receptor-positive, HER2 negative breast cancer, are generally treated with anti-estrogen treatment and are sometimes also recommended to have chemotherapy. Since these tumors don't always respond well to chemotherapy, tests have been developed that provide more information about how much benefit, in terms of reduction of the likelihood of cancer coming back, an individual patient is likely to get from treatment with chemotherapy. It is important that the benefit of a treatment outweighs the risk of toxicity from the treatment. Two of those tests are called Oncotype DX and MammaPrint. And they have recently been tested in large clinical trials. So TAILORx is a large prospective trial that tested the Oncotype DX assay. In the Oncotype DX assay, a tumor is tested to get more information about how likely a cancer is to return and how much benefit the patient is likely to get from chemotherapy. Scores on this assay can range from 0 to 100. Previously, a study showed that patients whose tumors had scores of 10 or less, and who received five years of anti-estrogen treatment, were very unlikely to have their tumors return. So chemotherapy is not recommended for them. For patients with higher scores, above 30, we also already knew that chemotherapy is likely to decrease the chance of cancers in those patients, and, so, therefore, we generally recommend chemotherapy for women with higher scores. In the TAILORx trial, the recently reported trial, more than 6,700 women with hormone receptor-positive, HER2 negative, lymph node-negative breast cancer had their tumors tested and were found to have Oncotype DX recurrent scores between 11 and 25, which is in that intermediate range or at the higher end of the low range. Before this trial was conducted, many people with tumors like these, in the intermediate range, were treated with both chemotherapy and endocrine therapy because we weren't sure how much benefit they would obtain from chemotherapy, and we didn't want to leave out a potentially helpful treatment. In this trial, patients were randomized, or randomly assigned by a computer, to treatment with chemotherapy followed by endocrine therapy or to treatment with endocrine therapy alone. The trial was mainly looking at whether leaving out chemotherapy would increase the likelihood of invasive cancer returning. And, luckily, overall, the trial showed that the likelihood of cancer returning in those patients who got endocrine therapy alone, without chemotherapy, wasn't significantly different compared to those who were treated with chemotherapy followed by endocrine therapy. They also looked, specifically, at the group of women who were 50 years of age or younger. So mostly premenopausal women. Now, this was an exploratory question, meaning it provides information that may be correct, but it hasn't been as fully tested as the main question about what do we do for all women? In these younger women, there appeared to be some benefit from chemotherapy in those whose tumors had scores from 21 to 25, and, also possibly, in those whose tumors had scores from 16 to 20. Therefore, we still consider giving chemotherapy to younger women with Oncotype DX scores in the middle range, from 16 to 25, but not to women over age 50. So that was the TAILORx trial. The MINDACT trial was a bit different. It was testing the MammaPrint assay and the trial also included primarily women with hormone receptor-positive, HER2 negative breast cancer. But in this case, most women's sorry lymph nodes were negative, although a few women had up to three lymph nodes involved. In that trial, patient's risk of disease recurrence was assessed in two ways. First, it was assessed based on clinical factors. So the size of the tumor, how many lymph nodes were involved, and the estrogen receptor, progesterone receptor, and HER2 receptors. Second, it was assessed based on genomic factors-- that was using the MammaPrint test. So if patients were low for both clinical factors and genomic factors, they only were treated with anti-estrogen therapy. If they were high for both clinical factors and genomic factors, then they were treated with chemotherapy followed by anti-estrogen therapy. However, if they were high for one and low for the other, then they were randomized to either endocrine therapy alone or chemotherapy followed by endocrine therapy. So it was a little bit of a confusing trial. In the MINDACT trial, those patients who were thought to be high risk based on their clinical risk, so the size of the tumor, the number of lymph nodes, but then found to be low risk on the MammaPrint assay. They found that there was no benefit to treatment with chemotherapy in terms of how likely a woman was to develop distant metastatic disease. And if they were low risk, based on the clinical assessment, then there didn't appear to be a benefit of actually doing the test, the assay, because chemotherapy wouldn't be recommended for the patient, regardless of the results. So that was the MINDACT trial. So what are the new and updated recommendations for the guideline? Yes, so in this guideline, we, based on the TAILORx trial, we made new recommendations for use of the Oncotype DX results. All of these results apply to women with hormone receptor-positive, HER2 negative, lymph node-negative breast cancer. So for women older than age 50, if they have an Oncotype score of 25 or lower, then clinicians may offer endocrine therapy and no chemotherapy. However, for women age 50 or under, if they have an Oncotype score of 15 or lower, 15, then, clinicians may offer endocrine therapy and no chemotherapy. But if the score is 16 to 25, then chemotherapy can be considered in addition to endocrine therapy. So it made a difference in that gray area in the middle. For all women with score 26 to 30, chemotherapy may be considered. And for scores above 30, chemotherapy should definitely be considered. The data from the MammaPrint trial actually aren't that new. Results from that trial were originally published in 2016. However, that was after the original guideline was published, so we wanted to add these results to these updated guidelines for completeness. For a patient with hormone receptor-positive, HER2 negative, node-negative breast cancer, who is thought to be at high clinical risk of breast cancer recurrence, if the MammaPrint assay shows low genomic risk, then treatment with chemotherapy can be avoided. If a patient is thought to be at low clinical risk, the MammaPrint should not be used as chemotherapy can be avoided regardless. And for a patient with hormone receptor-positive, HER2 negative breast cancer, but who has one to three positive lymph nodes, who is thought to be at high clinical risk of breast cancer recurrence, if the MammaPrint assay shows low genomic risk, then it is possible that chemotherapy could be avoided, especially if only one lymph node is involved. So I think the bottom line for this part is that both of these tests-- there are now women who previously would have been recommended to have chemotherapy that maybe now we can avoid chemotherapy based on using these assays on their tumors. So why are these changes so important and how will they affect practice? Yes, that's a good question. Before the publication of the TAILORx trial, we had good information about how to treat patients who had either very low or very high Oncotype scores. But we really weren't sure how best to treat those patients who scores fell in the middle. Now, we have important information to guide decisions about chemotherapy for patients with intermediate scores. For many patients with scores in this range, these new results mean they will be able to avoid chemotherapy and just get endocrine therapy. While these results don't give us answers for every patient, they do provide more information that oncologists can use when having discussions with patients about the benefits and risks of chemotherapy. And what does this mean for patients with early-stage invasive breast cancer? And what should they talk to their doctors about? So as a result of both of these trials, we now have additional tools that can help oncologists provide more individualized treatment recommendations for patients and really assess whether or not chemotherapy, in addition to endocrine therapy, is likely to provide benefits. Knowing which patients' tumors will respond to chemotherapy can help some patients avoid unwanted side effects from a treatment that's not likely to actually give them much benefit. Now, these tests aren't appropriate for everyone and don't provide all the answers, but they are an important step in the right direction for providing more personalized treatment for women newly-diagnosed with certain types of breast cancer. Patients should talk with their doctors about whether these tests are right for them when they're making important decisions about whether or not they should receive treatment with chemotherapy. Great. Thank you, Dr. Henry, for this informative overview of the guideline. Keeping these clinical practice guidelines updated is really crucial and it takes a lot of careful thought to ensure these recommendations represent the evidence. So thank you for coming on the podcast to discuss the "Role of Patient and Disease Factors in Adjuvant Systemic Therapy Decision-Making for Early-Stage, Operable Breast Cancer: Update of the ASCO Endorsement of CCO Guideline." Thank you very much for the opportunity to talk with you today. And thank you to all of our listeners for tuning into the ASCO Guidelines Podcast Series. To read the full guideline, go to www.asco.org/breast-cancer-guidelines. And if you've enjoyed what you've heard today, please rate and review the podcast and refer the show to a colleague.