Recurrence Patterns in Early-Stage HR+ Breast Cancer

Mark Pegram, MD: Let’s talk about late recurrence. This is the bane of our existence with hormone receptor [HR]–positive disease. Triple-negative and HER2 [human epidermal growth factor receptor 2]–positive tend to recur early if they do relapse, usually in the first 2 to 3 years. But ER [estrogen receptor]–positive disease can recur 10, 15, or 20 years after the fact. There’s a stubborn 1% or 2% risk of relapse per year for about 20 years. How do we identify those patients?

Lee Schwartzberg, MD, FACP: That’s a great question. We’re still struggling in some cases to identify them. It’s well established that over half of the recurrences occur after year 5. Our traditional thinking, and what’s out there in popular culture, that you’re home free if you’re disease-free at 5 years, unfortunately isn’t true for HR+ disease. That’s a difficult discussion that I have with our patients all the time, that we have to continue to monitor these patients, particularly if they’re at higher risk. It was very sobering a few years ago when the Early Breast Cancer Trialists’ Collaborative Group looked at the recurrence rate for up to 20 years, even in patients who had T1N0 tumors. It continues up through 20 years. Of course, the larger the tumor in terms of T size or the more nodes that are involved, the curves shifted upward as well. This is a substantial problem going out to 20 years.

Mark Pegram, MD: In that data set between year 5 and year 20, there was a 13% absolute risk of relapse by year 20. That’s only counting the relapses between years 5 and 20. That’s excluding the relapses in the first 5 years.

Lee Schwartzberg, MD, FACP: Right. It’s an older set. We’re looking back in time, and hopefully we’re doing better with the advent of better classification, better surgery, better node identification, and the addition of AIs [aromatase inhibitors]. It’s a combination of everything. But it’s still very sobering. It’s definitely an issue.

Mark Pegram, MD: Another common question that comes up is regarding clinical things to look out for, in follow-up visits of early stage disease. What are the main sites of recurrence for hormone receptor–positive disease? How does that compare with other types of breast cancer?

Lee Schwartzberg, MD, FACP: I don’t think that has changed very much. We’ve known for a long time that HR-positive breast cancer has a propensity for soft tissue and bone, and that the majority of patients have either bone only and maybe 15% to 20%, and bone plus other sites as initial diagnosis of metastatic disease. Then, of course, they become visceral as well. We’re seeing a bit of shift with the advent of more intensive adjuvant therapy. It remains to be determined whether we’re seeing more visceral disease, but bone disease remains the most common.

We also thankfully see less CNS [central nervous system] involvement, at least at first diagnosis of metastatic disease, than we would with either triple-negative or HER2+ breast cancer, which have a high propensity for CNS [involvement]. As we treat patients in the metastatic setting for years, we may see a change in the pattern, as we typically do, with more visceral disease in the lung and liver and then perhaps CNS. But that’s a late finding in HR+ breast cancer. I don’t think guidelines recommend routinely scanning asymptomatic patients at the diagnosis of metastatic disease, nor do I do so in my clinical practice. What’s your experience with that?

Mark Pegram, MD: For node-negative early stage patients with hormone receptor–positive disease, staging isn’t necessary. If the clinical exam and laboratory parameters are all nominal, then I agree with you. In the absence of signs or symptoms, you don’t have to do a full staging exercise either. Once you start to get into patients with multiple positive lymph nodes, then that shifts and we’ll typically do CT scans and a bone scan or a PET [positron emission tomography]–CT.

Lee Schwartzberg, MD, FACP: Right, for stage IIB or certainly for stage III cancers. The guidelines are consistent with that recommendation as well.

Transcript edited for clarity.