The purpose of this study is to estimate the overall survival (OS) for US participants diagnosed with metastatic colorectal cancer (mCRC) by using Flatiron Health's individual patient level data.

Inclusion Criteria:

• Metastatic Colorectal Cancer (CRC) participants in the Flatiron database as defined by:
• Diagnosed with CRC (ICD-9 153.x or 154.x or ICD-10 C18x, or C19x, or C20x, or C21x)
• Pathology consistent with CRC
• At least two documented clinical visits on or after January 1, 2013
• Evidence of Stage IV or recurrent metastatic CRC diagnosed on or after January 1, 2013
• Participants with high levels of microsatellite instability (MSI-H) and/or mismatch repair (MMR) protein deficiency (dMMR)
• Participants who received 2L therapy of interest on or after the initial mCRC diagnosis date
• Participants who had at least 1 month medical data during the prior to and post periods; however, participants who died within 1 month after the index date will not be excluded from the study

Exclusion Criteria:

• Participants <18 years of age at index date
• Participants who received clinical trial drug during the prior or post periods

Participants who were diagnosed with mCRC and received 2L therapy of interest were selected from Flatiron Health's data from January 2013 through March 2019.

2L therapies of interest included:

• FOLFIRI and bevacizumab
• FOLFOX and bevacizumab
• CAPEOX and bevacizumab
• FOLFIRI and panitumumab
• FOLFIRI and ziv-aflibercept
• FOLFOX, bevacizumab and other (non I-O)
• FOLFIRI, ziv-aflibercept and other (non I-O)
• FOLFIRI, bevacizumab and other (non I-O)
• Nivolumab monotherapy
• Pembrolizumab monotherapy