Weekly App Check-Ins Eased Fatigue in Metastatic Breast Cancer

For patients with metastatic breast cancer, symptoms such as fatigue can affect daily life. Regularly tracking symptoms on a smartphone and alerting the cancer care team when they worsened was associated with lower fatigue and better physical functioning according to a PRO B clinical trial published in JAMA Oncology.

The findings included 909 patients with metastatic breast cancer across 52 breast cancer centers in Germany. Patients were randomly assigned to weekly digital symptom monitoring or usual care.

What did the study find about fatigue?

Patients reported symptoms on a standardized scale where 50 represents the average for the European general population, with higher scores indicating more fatigue.

At six months, the adjusted mean fatigue score was 54.5 in the digital monitoring group and 59.9 in usual care. The 5.4-point difference exceeded the 3.3-point threshold for clinically meaningful improvement.

The difference remained over the year. Fatigue scores were 5.2 points lower in the monitoring group at three months, 6.8 points lower at nine months and 5.2 points lower at 12 months. Results were similar across age groups, sites of metastasis, breast cancer subtypes and performance status.

What did the study find about physical functioning and quality of life?

Physical functioning was better in the monitoring group at every point measured, by 3.7 points at three months, 4.0 points at six months and 5.1 points at nine months. The differences exceeded the 3.2-point threshold the researchers set for meaningful change.

Overall quality of life did not follow the same pattern. The difference between groups at six months was 0.8 points, below the 2.9-point threshold for meaningful change.

Emotional functioning was also higher in the monitoring group, by 4.3 points at six months. However, the researchers noted that this measure differed between groups at baseline and was not a prespecified end point.

Did monitoring affect hospital stays or survival?

Among patients with available insurance claims data (25.9%), hospitalization and emergency department visit rates at 12 months were lower in the monitoring group. The researchers described these results as supportive and exploratory because the data covered 25.9% of the trial population.

An exploratory analysis found 12-month overall survival of 87.6% in the monitoring group and 84.7% in the usual-care group. The researchers cautioned that the analysis was underpowered and hypothesis-generating. More patients in the usual-care group were also lost to follow-up, which could have influenced the comparison.

Time to the first change in systemic therapy did not differ between groups. The researchers wrote that the data do not support earlier treatment changes as the main reason for the difference. They pointed instead to earlier clinical contact, supportive care and communication between patients and care teams as possible explanations.

What could these findings mean for patients with metastatic breast cancer?

Metastatic breast cancer is treatable but not curable, and patients may receive different systemic treatments over time. Symptoms can result from cancer, treatment or other factors and may change throughout care. Fatigue can be missed in routine practice because it comes and goes and is not always apparent during an appointment.

The study found that routinely asking patients about changes was associated with earlier identification of symptoms and functional declines. Clinicians could be alerted when symptoms worsened and then determine whether patients needed additional support or evaluation. In PRO B, alerts were most often triggered by declines across several areas of daily functioning. The researchers said this type of multidomain decline may signal the need for further assessment.

The researchers noted several limitations. Only patients with smartphone access and German language proficiency could enroll. Baseline assessments were completed after randomization, and because the trial was not blinded, patients may have known which group they were in, potentially contributing to baseline differences. Questionnaire completion and dropout also differed between groups, and the primary end point was changed early in the trial from fatigue at 12 months to fatigue at six months.

The researchers concluded that digital patient-reported outcome monitoring was associated with reductions in fatigue and improvements in physical functioning. They noted that the findings support "further evaluation of alert-based PRO monitoring in routine oncology care."

How did digital symptom monitoring work?

Patients in the digital monitoring group completed weekly smartphone questionnaires about symptoms and aspects of their health, including fatigue and physical functioning. The questionnaires were designed to identify meaningful changes in symptoms.

When responses indicated that symptoms were worsening, an automated alert was sent to a nurse or physician at the patient's cancer center, who contacted the patient by telephone within 48 hours.

Patients in the usual-care group completed questionnaires every three months and did not receive automated alerts.

Each week, patients in the monitoring group answered 51 to 57 questions from a validated European Organization for Research and Treatment of Cancer (EORTC) question bank covering symptoms and physical, role, emotional, social and cognitive functioning. Questionnaires arrived on the same weekday each week, with reminders for up to two days.

What set off an alert to the care team?

An alert was triggered when responses showed that symptoms had worsened compared with previous weeks or when patients reported a decline in overall health. The alert was emailed to a nurse or physician at the patient's cancer center who had been trained to follow the trial's procedures.

Among 24,180 follow-up assessments in the monitoring group, 3,019 triggered an alert, representing 12.5% of assessments. Patients received a median of five alerts during the study. Declines in social, role, emotional and physical functioning triggered alerts more often than individual symptoms. Fatigue accounted for 20.6% of alerts.

Alerts led to patient contact 2,559 times, with 2,194 calls (85.7%) occurring within 48 hours. Study nurses made 66.6% of calls, followed by physicians at 29%. Of the alerts, 48.5% required no action beyond the conversation, while 44.2% were resolved by telephone consultation. Calls covered infections and colds (14.6%), treatment side effects (8.1%), pain and musculoskeletal symptoms (5.8%), psychological or emotional concerns (5%), gastrointestinal complaints (4.7%) and fatigue or reduced well-being (4.2%). Another 3% led to a scheduled appointment, while 4.3% reached patients who were already hospitalized.

Patients in the monitoring group returned questionnaires more often than those in the usual-care group, 89% versus 74% at six months.

Reference

1. Karsten MM, et al. "Electronic Patient-Reported Outcome Monitoring With Alert-Based Interventions in Metastatic Breast Cancer: A Randomized Clinical Trial." JAMA Oncology. Published August 6, 2026.

For more news on cancer updates, research and education, don't forget to subscribe to CURE®'s newsletters here.