Recent reports suggest that falls increase by 25%-50% in cancer patients and are linked to treatment-related side effects, such as chemotherapy-induced peripheral neuropathy (CIPN), that alter mobility (gait and balance). Falls and functional impairments in cancer patients remain largely unrecognized and under-treated, in part because it is not yet known what level of symptoms impact mobility, the specific mobility deficits that increase fall and disability risk, or which patients are most at risk. Our long-term objective is to prevent falls and disability associated with cancer treatment by informing clinicians about which and when patients show increased risk for falls and functional decline and informing rehabilitation providers about which mobility deficits to target. A critical first step toward this objective is to characterize the natural trajectories of symptoms, functioning, and falls across the in-treatment and recovery phases of cancer care. To achieve this goal, we will use detailed symptom tracking, simple clinical tests, passive continuous monitoring of daily mobility and physical activity, and self-report falls and disability collected before, during, and one year after treatment in 200 patients prescribed neurotoxic chemotherapy for cancer. The Specific Aims of this study are: 1) to characterize trajectories of neuropathy symptoms and functioning (objective mobility, physical activity, self-report functioning and disability) across treatment and one year of recovery among persons receiving neurotoxic chemotherapy for cancer and 2) Determine the simplest predictors of symptom and functioning trajectories to identify patients in whom different treatment options should be considered and/or who would benefit from early and targeted rehabilitation interventions. This study is innovative because it will be the first study to 1) reveal how cancer treatment could lead to increased risk of falls and disability in survivorship, 2) measure changes in symptoms, mobility and falls across a course of chemotherapy and into recovery, 3) employ continuous passive monitoring technologies as sensitive and specific measures of mobility and activity changes during daily life; and, 4) apply a novel analytic approach - growth mixture modeling (GMM) - to identify the distinct trajectories of changes in symptoms, functioning and falls associated with neurotoxic chemotherapy. Collectively the knowledge gained from this study can be used to identify which patients might benefit from early intervention via alterations in treatment plans and/or referral to rehabilitation. Findings from this study could provide new information for oncology teams to improve patient safety and enhance survivorship care plans for those receiving neurotoxic chemotherapies. Currently, clinical practice guidelines focus on pharmacologic management of pain associated with CIPN, which remains suboptimal, with little attention to prevention of falls and functional decline. This study could have a significant impact by defining the natural trajectories of functional declines related to CIPN so that early detection efforts can be integrated into the clinical pathway of patients receiving neurotoxic treatment and targeted care provided for at-risk patients.