Understanding New Cachexia Subtypes Through Observational Epidemiological Research

Inclusion Criteria: * Have a primary diagnosis of unresectable or Stage IV 1) non-small cell lung cancer (NSCLC), 2) pancreatic adenocarcinoma, or 3) colorectal cancer (CRC). Note: Patients do not need to have cachexia to be eligible * Plan to start first line systemic anti-cancer therapy (chemotherapy, immunotherapy, targeted therapy) in the next 6 weeks or has started first-line systemic therapy in the previous 6 weeks. Note: Patients who received systemic anti-cancer therapy previously as part of adjuvant or neoadjuvant therapy and have since recurred are still eligible if such treatment was longer than 6 months prior to enrollment. * Have an an Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1 or 2. * Be able to understand, speak and read English. * Be 18 years or older Exclusion Criteria: * Have contraindications to physical function assessments (30-second bicep curl, Timed-Up-And-Go test, or 30-Second Sit to Stand test) per the treating provider or their designee. * Have any planned major surgeries within the next 3 months after enrollment to the best knowledge of the investigator/treating provider or their designee. * Have received chemotherapy or surgery for separate primary cancer within the past 3 years other than non-melanoma skin cancer. * Be pregnant or within 6 months postpartum.