Beyond symptoms: wearable digital biomarkers for subclinical detection of chemotherapy-induced peripheral neuropathy.

Background: Chemotherapy-induced peripheral neuropathy (CIPN) is the most prevalent dose-limiting toxicity of taxane-, platinum-, and proteasome inhibitor-based regimens, yet clinical management has a structural flaw: assessment depends on CTCAE clinician grading that registers symptoms only after axonal degeneration has reached an irreversible stage. Main body: Quantitative sensory testing studies demonstrate that vibration perception, thermal detection, and sudomotor function deteriorate before patients report numbness or pain, suggesting a subclinical window of one to two chemotherapy cycles. Whether detection within this window can prevent permanent nerve injury remains biologically plausible but prospectively unestablished. Wearable sensors-inertial measurement units for gait, plantar pressure insoles, electrochemical skin conductance devices, and vibration sensors-have demonstrated proof-of-concept capacity to capture subclinical CIPN signals, but evidence remains largely cross-sectional with limited longitudinal validation. This Perspective distinguishes the conceptual framework for subclinical CIPN surveillance from the currently available clinical validation evidence. I systematically categorize four sensing modalities by neuropathological substrate, provide a cross-modality readiness comparison, and identify translational barriers including absent alert thresholds and confounding factors such as age, diabetes, anemia, and fatigue. I propose a phased prospective validation framework; specific monitoring recommendations should be regarded as hypotheses for testing rather than current clinical guidance. Conclusion: Wearable sensors should not replace patient-reported outcomes but may add an objective neurotoxicity monitoring layer whose capacity to improve clinical outcomes requires prospective validation.