About this trial

Colorectal cancer is the third most common cancer in Europe. The standard of care recommended first line treatment for some colorectal cancer includes the treatment with fluoropyrimidines plus oxaliplatin with or without bevacizumab. In many cases this treatment shows good results; however, there are patients who do not benefit from this treatment or develop resistance to this therapy. It is not known at present who responds best to such treatment and this study proposes to test patients’ surgical tissue/blood samples and follow their response to treatment in order to find ways of making this prediction.

About 163 patients from centres in three European countries, Ireland (Beaumont Hospital, Bon Secours Cork, St. Vincent’s University Hospital, Tallaght University Hospital, University Hospital Galway), Germany (Universitätsmedizin Mannheim, Onkologische Schwerpunktpraxis Heidelberg, Onkologische Schwerpunktpraxis Speyer) and Spain (Hospital Universitari Vall d’Hebron, Institut Catala d’Oncologia) will take part in the study.

Patient Profile

This study is open to men and women over 18 years of age with metastatic colorectal cancer. Patients must have a type of tumour, called microsatellite stable RAS mutant.

To learn more about this study please visit: COLOSSUS explainer video.

Where’s this trial being run?

Beaumont Hospital, Bon Secours Cork, Tallaght University Hospital, and University Hospital Galway

Can I join this study / trial?

The first thing you do is to talk to your doctor and/or the cancer trials research team in your hospital. The contact details for the cancer trials research units in Ireland is here.

Why not Print this page and bring it with you. It will help your doctor and research team advise you.

For more detailed information


Here’s a list of questions you may have for your doctor or local cancer research team.

Summary Data

Number: 17-26
Full Title:

Identification of new patient stratification tools in microsatellite stable (MSS) RAS mt metastatic Colorectal Cancer (mCRC).

Principal Investigator: Prof Ray McDermott (Chief Investigator, Ireland) Prof Matthias Ebert (Chief Investigator, Germany) Prof Josep Tabernero (Chief Investigator, Spain)
Type: In-House

Cancer Trials Ireland

Recruitment Started: Global: September 2018
Ireland: September 2018
Global Recruitment Target: 163
Ireland Recruitment Target: 85