Symptom Monitoring in Metastatic Breast Cancer: What Patients Should Know

For patients with metastatic breast cancer, new or worsening symptoms can occur between appointments, and it may not always be clear when to contact the cancer care team.

Dr. Maria Margarete Karsten and her colleagues studied whether weekly digital symptom monitoring could help identify these changes sooner in the PRO B trial. Patients completed weekly smartphone questionnaires, with alerts prompting their care team to follow up when symptoms worsened.

Beyond the study findings, Karsten said patients described the monitoring as a “safety net” and reported feeling more in control of their symptoms.

In an interview with CURE, Dr. Karsten, senior physician at the Breast Center at Charité – Universitätsmedizin Berlin, discussed what patients told researchers about weekly symptom monitoring, why symptoms may go unmentioned during appointments and what this approach could look like in routine cancer care.

CURE: What made you want to study weekly symptom monitoring for patients with metastatic breast cancer?

Karsten: Cancer therapy in general, but also breast cancer care, has changed quite dramatically over the last 10 to 15 years. We have a lot more therapeutic targets, we have a lot more drugs and the treatment pathways are much more complicated.

The good thing is that because of this, patients with advanced breast cancer are living longer. But we're still often not able to see them as frequently as we would like, at least from my clinical perspective.

I always feel like, “How are they doing at home?”

The side effects with some of these newer drugs have changed quite a bit, and we as a team felt we needed closer monitoring of these side effects and in a more detailed way than we could do during an office visit every three to four weeks.

We felt we needed to develop something to help us and the patient systematically collect how they are doing and then have an alert system. If something is off, we get notified and can reach out to the patient.

What did patients tell you about having their symptoms monitored each week?

We did a lot of interviews after the study, and patients told us that they felt like they had better control of their symptoms. They felt like they had a second safety net that they could fall back on.

One patient said, “It actually saved my life twice.” She wasn't sure what to do with her symptoms, and she didn't want to reach out to anybody. She didn't feel like it was already something critical and thought she could wait until her next doctor's visit.

But it turned out that it was something that needed attention.

Why might symptoms go unmentioned during a cancer appointment?

There are so many technical things to discuss during a visit that sometimes these things get missed.

From the patient side, sometimes afterward they think, “Oh, I should have asked this,” or, “I should have told her about that.” But then the appointment is already over.

I used the monitoring data in clinic. I could look at the patient's data from the week before and already see if there had been a change. Then I could address that immediately during the appointment and say, “I see you're having more problems with this. What's going on?”

We know there can be underreporting of symptoms by patients with cancer and differences between what patients experience and what health care providers detect during a short appointment.

What did weekly symptom monitoring look like for patients in the trial?

In the trial, patients filled out the questionnaire, but they didn't receive a response directly through the app. That was on purpose because this was new, and we didn't want to worry anybody based on something that was still theoretical.

If something was detected, patients could get a call from somebody on their care team saying, “How are you doing? What's going on?” Then they could discuss what was happening with their nurse, physician or another member of their care team.

What we're doing now in routine care is different. The patient could get immediate feedback saying that no new symptoms were detected and everything is stable. Or there could be something the algorithm detected that isn't worrisome, but the patient could take steps to improve it.

There could also be a level where the algorithm detects something in that patient's individual symptom journey and tells them, “Your care team will contact you.”

If the monitoring system sends an alert, does that mean something is wrong?

No. We made the algorithm very sensitive, and we explicitly made it that way.

In about half of the alerts, it wasn't something that triggered a serious medical intervention. It could be handled with a short telephone intervention or by rescheduling an appointment.

This is also not meant for a crisis. Every time in the study, we told patients that if they felt critically ill, they shouldn't use the app — they should seek emergency medical care.

This is more for monitoring on a regular basis when you're not in a crisis. If the system detects deterioration compared with your previous well-being, the health care team can reach out and personally ask, “What's going on?”

The study found patients experienced less fatigue with weekly monitoring. What could that difference mean for someone living with metastatic breast cancer?

Fatigue is difficult, but that's also why we picked it, because fatigue is very burdensome for a lot of patients.

The 5.4-point difference is hard to translate. It wouldn't be correct to put it into a percentage, but it is a clinically meaningful change in the level of fatigue.

In more understandable terms, you feel that you're not as exhausted as you used to be before.

We also saw changes beyond fatigue. Physical functioning improved, and we saw better control of symptoms such as diarrhea or nausea.

How could having this symptom information change a patient's regular appointment with their care team?

I could look at the patient's data from the week before and already see if there was a change. Then I could address that immediately during the appointment.

I could say, “I see you're having more problems with this. What's going on?” Having that information can help pinpoint something that otherwise might not come up.

There are so many things to discuss during a visit that sometimes these things get missed. From the patient's side, they may think afterward, “Oh, I should have asked this,” or, “I should have told her about that.” But then the appointment is already over.

What needs to be in place for this type of monitoring to work in routine cancer care?

From a technical perspective, we tried to make it as simple as possible. We have an online platform that the physician can access, and patients can download the app. The physician connects the patient to the system, and then they can start.

Of course, there are other requirements, such as contracts and processes within the health care system. But from a technical perspective, we tried to make it as simple as possible so that people could really use it.

What do you hope happens next with weekly symptom monitoring?

We're trying now to bring this into routine care for patients with breast cancer in Germany. We're hopeful that it will be covered by German statutory health insurance.

We're already talking to health care providers and clinicians, and we're setting it up across Germany. We're hopeful that we will start in January.

Of course, there are a lot of other patients with cancer who could also need something like this. We have a lot of other dreams about what we would like to do and where we think there could be improvements in oncology care, but that's basically our next step.

What would you want patients with metastatic breast cancer to take away from your experience with symptom monitoring?

We're not the only ones doing this. We did this for advanced breast cancer, but if you have the ability to join a monitoring system, I would highly recommend that you do it.

Editor’s note: This interview has been edited for clarity and conciseness.

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