 This study aims to measure association between biosensor data, performance status and patient-reported outcomes. This study will also evaluate the feasibility of using Fitbit activity monitors in a cancer population to capture objective activity data. The study will be recruiting patients with advanced cancer diagnoses stage 3 or 4 and will be referred by the treating oncologist. This is an exploratory study that will follow patients with stage 3-4 cancer for a period of 15 days. Subjects will be provided with a Fitbt Charge HR activity monitor. They will be requested to wear the Fitbit Charge HR at all times, except for while bathing or performing other activities where the activity monitor can become submerged in water. Subjects will be asked to wear the Fitbit Charge HR for two weeks. They will be seen in the clinic at baseline, at the end of week 1 day 8 and at end of 2 weeks day 15 for physical exam, evaluation of performance status by both treating oncologist and practice nurse using standardized scales and administration of PROMIS questionnaires. Patients will be followed up to 6 months after the last clinic visit for adverse events, hospitalization and survival. Thirty subjects will be enrolled in this study. 