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DFG approves Transregional Collaborative Research Center involving the Faculty of Medicine at the University of Freiburg / Focus on tumor environment as a brake on therapy

Colorectal cancer is curable - if it is detected early and can be completely removed surgically. It becomes more difficult with advanced disease. Here, immunotherapies that activate the body's own defense system are seen as a beacon of hope. However, they only work in around one in six people affected. The new Collaborative Research Centre TRR 417 is therefore dedicated to researching the so-called tumor microenvironment - the network of cells in which the tumor cells grow. The aim is to change this in a targeted manner in order to make treatments more effective. The network, which is funded by the German Research Foundation (DFG), is coordinated by Goethe University Frankfurt. In addition to the University of Freiburg, the Friedrich-Alexander University Erlangen-Nuremberg is also involved.

"Tumors are not isolated collections of cells - they are in close contact with their environment. This microenvironment can significantly hinder the effectiveness of treatments - especially in the case of metastases in the liver and peritoneum. This is exactly where we come in," says Prof. Dr. Stefan Fichtner-Feigl, member of the Medical Faculty of the University of Freiburg and Medical Director of the Department of General and Visceral Surgery at the Freiburg University Medical Center. "The funding of TRR 417 is a valuable recognition of our work. It gives us the opportunity to find new ways to create hope for patients with previously therapy-resistant tumors."

"We are very pleased about this research funding. It shows: Only through close networking and joint exchange can we achieve progress that will improve the treatment of colorectal cancer and thus help our patients," says Prof. Dr. Lutz Hein, Dean of the Faculty of Medicine at the University of Freiburg.

Why only a few colorectal tumors respond to immunotherapies

Around 10 to 15 percent of intestinal tumors respond well to modern immunotherapies. So-called immune checkpoint inhibitors are often used, which neutralize the tumour's protective mechanisms. This makes the tumor "visible" to the immune system so that the body's own immune cells - T cells - can take targeted action against the cancer cells.

For the majority of bowel cancer patients, however, immunotherapies have so far had little effect. Even traditional treatment approaches such as chemotherapy and radiotherapy often reach their limits. The reason for this is the complex tumor microenvironment: a dynamic environment consisting of connective tissue cells (fibroblasts), immune cells, blood vessels and intestinal microorganisms. These so-called stromal cells are manipulated by the tumor - and unintentionally support its growth and resistance to therapies.

Collaboration between medicine, biology and data science

In the new Collaborative Research Center/Transregio TRR 417 "Cellular Communication in the Stroma of Colorectal Cancer: From Pathophysiology to Clinical Translation", researchers from the fields of medicine, biology and data science are pooling their expertise."We want to find out how we can specifically change the tumor microenvironment and use it therapeutically to improve treatments and make it accessible for immunotherapies - especially for colorectal tumors that have so far responded poorly to existing therapies," says Prof. Dr. Florian Greten, cancer researcher at the Georg-Speyer-Haus and Goethe University Frankfurt and spokesperson for the new TRR 417.