A Prospective Study of Physical Function in Adults Who Receive Systemic Therapy for Stage I-III Gastroesophageal Cancer, FAST-GO Study

PRIMARY OBJECTIVE: I. To determine the change in physical function from baseline to 6 months of treatment, as measured by the short physical performance battery (SPPB). OUTLINE: This is an observational study. Patients undergo blood sample collection as well as complete surveys, physical function tests and may complete an interview on study.