An Observational Study Called STAR-T to Learn More About the Sequential Treatment With Regorafenib and TAS-102 in Adults With Metastatic Colorectal Cancer Under Real World Conditions

This is an observational study using data that has been collected from participants who received their usual treatments.

Metastatic colorectal cancer (mCRC) is a cancer of the colon (large bowel) or the rectum (lowest part of the bowel just before the anus) that has spread to other parts of the body.

Regorafenib is an anti-cancer drug that blocks several proteins, called enzymes, which are involved in the growth of cancer. The combination of anti-cancer drugs trifluridine and tipiracil is called TAS-102. It prevents cancer cells from growing and multiplying.

Both regorafenib and TAS-102 are approved treatments for metastatic colorectal cancer and are available for doctors to prescribe to people with mCRC after previous lines of treatment have been unsuccessful.

Regorafenib and TAS-102 work in different ways and impact people differently. People might receive one of these drugs first and followed by the other. The best sequence for taking these drugs is still unclear.

Researchers have also found that TAS-102, when taken with another anti-cancer drug called bevacizumab, helps people live longer than when taken alone.

To better understand the impact of the sequence of taking regorafenib and TAS-102 (with or without bevacizumab), more knowledge is needed about how these work together in people with mCRC in real world settings.

The main purpose of this study is to learn more about the characteristics and impact of treatment in people with mCRC who received regorafenib and TAS-102 (with or without bevacizumab) one after the other. This information will be grouped based on their treatment sequence and age group (less or more than 65 years old).

In addition, the researchers want to learn about :

* how long participants were treated with regorafenib and TAS-102 taken one after the other in a sequential order, * any treatment for mCRC that the participants received after the sequential treatment, * any treatment received for a condition in which the bone marrow cannot make up enough blood cells (a common side effect of cancer treatment), during the sequential treatment, * if and how often white blood cells that fight infection decreased during the sequential treatment, * the number of hospital or testing facility visits that participants had during the sequential treatment, and * how long did participants live (also called overall survival).

The participants in this study had already received regorafenib and TS-102 (with or without bevacizumab) as part of their regular care from their doctors.

The data will come from the participants' information stored in an electronic health records database called Flatiron mCRC EDM. Data collected will be from January 2015 to December 2022.

Researchers will only look at the health information from adults in the United States of America.

In this study, only available data from routine care is collected. No visits or tests will be required as part of this study.