This study will examine the association between low muscle mass (myopenia) at diagnosis and chemotherapy toxicity in older adults with newly diagnosed advanced colorectal cancer.

This is a prospective cohort study that examines the impact of myopenia on chemotherapy toxicity in overall survival (OS) in older adults with newly diagnosed metastatic colorectal cancer (CRC) receiving 5-Fluouracil (5FU)systemic chemotherapy. The study also explores the mediating influence of genetic variation in the association between myopenia and chemotherapy toxicity.

Inclusion Criteria:

• Newly diagnosed metastatic CRC or newly recognized metastatic recurrence of CRC >= to 3 months (12 weeks) from completion of treatment of non-metastatic CRC.
• Planning to or recently started to undergo undergo immunotherapy and/or 5-FU based chemotherapy as a first line of treatment. 5-FU chemotherapy can be 5-FU alone or in combination with oxaliplatin and/or irinotecan +/- immunotherapy. Capecitabine is also acceptable.
• Estimated life expectancy >= 6 months.
• Patients must be able to comprehend English or Spanish (for questionnaire completion).
• Ability to understand and the willingness to sign a written informed consent document.
• Patient eligibility is not dependent on BMI or weight. Patients with a significant (+- > 10%) body weight change in the previous 12 months are eligible for this study.

Exclusion Criteria:

• Patients enrolled on hospice.
• Prior systemic chemotherapy for metastatic colorectal cancer (ok if adjuvant chemotherapy completed >= 3 months (12 weeks) prior to this disease disease recurrence and treatment).
• Patients may not be receiving any other investigational agents.
• No untreated brain metastases. Patients with treated brain metastases are eligible.
• Patients on or planned to undergo radiation therapy in near future.

Diagnosed metastatic CRC or metastatic recurrence of CRC >= 3 months (12 weeks) from diagnosis at 60 years or older.

Wake Forest NCORP Research Base is committed to following the NIH Statement on Sharing Research Data (http://grants.nih.gov/grants/guide/notice-files/NOT-OD-03-032.html). As of July 2018, the WF NCORP RB signed an agreement with NCI to contribute de-identified data and data dictionaries from clinical trials conducted through our RB to the NCI NCTN/NCORP data archive within 6 months of primary and non-primary publications of phase II/III and phase III trials to https://nctn-data-archive.nci.nih.gov/. This will become the primary means for sharing raw data, and we will adhere to the guidelines spelled out in the NCTN/NCORP Data Archive Usage Guide. De-identified data from studies not covered by the agreement (e.g., phase II and observational studies) will be made available upon request. All data files will be de-identified. De-identification procedures will meet the HIPAA criteria as detailed in the Code of Federal Regulations, Part 45, Section 164.514.

6 months after publication for a 2 year duration

upon to request to NCORP@wakehealth.edu