A new study published in JAMA Network Open suggests that digital measures collected via patients’ personal smartphones may provide a scalable and low-burden method to monitor functional status in individuals with advanced cancer.
Straczkiewicz et al. conducted a cohort study at Dana-Farber Cancer Institute, USA, enrolling 85 female patients with recurrent gynaecologic cancers, including ovarian (64 patients), endometrial (12 patients), and cervical, vaginal, or vulvar (9 patients) malignancies. Participants were receiving systemic or targeted therapies and contributed data over six months using the Beiwe mobile health platform, which collects passive accelerometer and GPS information from smartphones.
Smartphone-based gait measures, including step count and cadence, and mobility measures, such as the number of important locations visited, time at home, and distance travelled, were derived from sensor data. These were compared with standard patient-reported outcomes, including the Eastern Cooperative Oncology Group Performance Status (ECOG PS), EuroQol-5D-5L (EQ5D) subscales, and Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS PF-6b).
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Key Findings
Step counts were strongly associated with functional status and quality of life. Patients with worse ECOG scores had significantly lower step counts (ECOG 3 vs 0: −1,838 steps per day; 95% CI, −2,688 to −1,008; P < .001).
Higher PROMIS PF-6b scores corresponded with higher daily step counts (72.64 steps per day per 1-point increase; 95% CI, 39.83–105.56; P < .001) and cadence (0.13 steps per minute; 95% CI, 0.02–0.25; P = .03).
Participants with better ECOG scores tended to visit more locations per day, indicating higher mobility and engagement.
Over six months, walking cadence declined slightly (−0.23 steps per minute; 95% CI, −0.42 to −0.03; P = .02), although step counts and other mobility measures remained largely stable.
The authors note that decreases in step count of around 1,000 steps per day have previously been linked to a 16% increase in the odds of hospitalisation or death in patients with advanced cancer, underscoring the potential clinical relevance of these digital measures.
Implications for Practice
These findings suggest that smartphone-based monitoring could provide real-time, objective insights into patients’ functional status without requiring additional devices or frequent patient input. Digital gait and mobility measures may complement traditional patient-reported outcome measures, helping clinicians identify changes in physical functioning and quality of life over time.
Limitations and Future Directions
The study was limited by its small sample size, single-centre design, and focus on female patients with gynaecologic cancers. Potential confounding factors such as baseline function and disease severity were not fully adjusted for.
Future research should examine how smartphone-based mobility metrics can complement gait measures to provide a holistic view of patient health, validate findings in larger and more diverse cancer populations, and explore the integration of these digital biomarkers into clinical workflows.
Straczkiewicz et al. conclude that smartphone-based digital measures may offer a robust, low-burden alternative to wearable devices for monitoring functional status in patients with advanced cancer, potentially supporting more personalised and timely clinical interventions.
Paper: Straczkiewicz, M, et al. Smartphone-Based Measures as Indicators of Functional Status in Patients With Advanced Cancer. JAMA Network Open. September18,2025.doi:10.1001/jamanetworkopen 2025.32488. Access online here.
