Reshma Jagsi, MD, DPhil: Hello, my name is Reshma Jagsi, and I’m the chair of the Department of Radiation Oncology at Emory University School of Medicine. I’m pleased to be here at the San Antonio Breast Cancer Symposium (SABCS) to present the IDEA study’s five-year outcomes.
OBR: What was the purpose and design of the IDEA study?
Dr. Jagsi: The IDEA trial was a prospective multicenter cohort study where 200 patients from 13 institutions across the United States consented to participate in a study of omission of radiation therapy after lumpectomy and endocrine therapy for five years. They consented to participate if they were eligible for this study based on [various] criteria. They were aged 50–69 years with stage I pathologic T1 N0 disease that was estrogen receptor– and progesterone receptor–positive and HER2-negative and also had a 21-gene assay recurrence score less than or equal to 18.
OBR: What were the key five-year outcomes?
Dr. Jagsi: The IDEA study showed that, at five years, the rate of recurrence was extremely low, as we had hoped, in this population that we had intentionally selected to have biologically favorable disease. As we all know, patients who are older (age 65–70 years) with stage 1 hormone receptor positive tumors are offered the option of omitting radiation treatment after lumpectomy, but younger postmenopausal women are not.
This study is not yet definitive, and there are many other ongoing trials. Long-term follow-up of this study is necessary before applying any of these results in practice. But this is an important first step forward because the rates of recurrence were a 99% recurrence-free survival at five years in this study, with two recurrences before five years, but also six recurrences seen after five years and a significant need for long-term follow-up as a result.
OBR: What further data are needed before these findings can be applied in practice?
Dr. Jagsi: Long-term follow-up of this trial and the others that are going on in this space will be absolutely essential to guide clinical practice. Right now, the standard of care for women who are in this younger postmenopausal category remains radiation treatment after lumpectomy, even if they have early-stage biologically favorable disease.
Our hope is that together with other trialists who are also exploring this space — including those in the National Cancer Institute Cooperative group system who are leading the large national randomized trial DEBRA (NRG-BR007) — that one day we will have more information to share with patients, so that they can make decisions that are individualized and right for them. We hope that one day, for patients like this, omission of radiation treatment may be a reasonable option.
Again, it’s important to remember that even in older women aged 65–70 years and older, where established trials have shown that omission of radiation treatment is reasonable, the risk of local recurrence is higher without radiation treatment. In those patients, it’s about 10% at 10 years compared with only 1% or 2% with radiation. It’s extremely important to gather the long-term data and share that with patients, because for some, that will be an unacceptable trade-off. For others, it will be something that they want to consider. That is the clinical implication.
OBR: What is the potential significance of these findings for patients?
Dr. Jagsi: When a patient is diagnosed with breast cancer, all clinicians know that there is a tremendous sense of loss of control, a robbing of agency. If we can return to patients a little bit of that control by giving them a series of options to which they can then apply their own values and their own preferences to make decisions that feel right to them, we have done a tremendous service. By no means should the IDEA trial be interpreted as trying to identify an option to avoid toxic, brutal, harsh, horrible radiation treatment.
I’m a radiation oncologist, and I will tell you that the regimens that we have, especially now, to treat breast cancer are extremely well-tolerated and, in fact, quite easy to administer. We have many regimens that patients in this trial would be eligible for that involve five treatments or less. This is not an awful treatment, and by no means should any patients who need radiation be scared off of receiving radiation by the fact that we’re doing research in this space.
The reason we do research like this — not only trying to see if we can omit radiation but seeing if we can scale back on surgery, seeing if we can scale back on systemic therapies like chemotherapy and hormonal therapy — the reason we look at those important questions is because we want to offer patients a choice so that they can weigh the burden and the side effects. Thankfully, the burden and the side effects these days of most of the things we offer to patients have been minimized through technological advances and clinical trials, in which many kind and generous patients have participated.
I think it’s incredibly important for us to do this kind of work and also reflect on the advances we’ve already made, which make the current standard of care, which is radiation treatment after lumpectomy, so tolerable for our patients.
This transcript has been lightly edited for clarity.
