Study Identifies New Biomarker for Colorectal Cancer Treatment

A study published in the journal Gut has identified a specific type of cell within tumors, known as CTHRC1(+) cancer-associated fibroblasts (CAFs), as a biomarker with potential for predicting treatment response and prognosis in colorectal cancer. The research, which analyzed samples from nearly 3,000 patients, suggests the biomarker could help guide treatment decisions, including the selection of patients for immunotherapy.

Study Overview and Methodology

The research was conducted by a multidisciplinary team from the Hospital del Mar Research Institute, the Institute for Research in Biomedicine (IRB Barcelona), and the CIBER Oncology area (CIBERONC). Validation of the biomarker utilized patient samples from several hospitals, including Hospital Clínico Universitario de Valencia, Hospital Universitario Germans Trias i Pujol, and Hospital del Mar.

The study process involved:

• Analyzing tumor cell RNA at a single-cell level across 17 patient cohorts to identify promising cell populations.
• Determining the proteins expressed by these cells.
• A validation process in which only cells expressing the CTHRC1 protein retained predictive capacity.

Key Findings and Biomarker Characteristics

CTHRC1(+) CAFs are connective tissue cells that form part of the tumor microenvironment. The study reported several key findings:

High levels of the CTHRC1 protein are associated with resistance to treatment.

• The biomarker enables the measurement of TGF-beta cytokine activity in the tumor microenvironment, which is linked to poorer disease outcomes.
• According to the researchers, the marker maintained predictive and prognostic performance across the different patient cohorts studied.

Potential Clinical Applications

The research indicates several potential applications for the CTHRC1(+) CAF biomarker in clinical practice:

• Prognosis and Treatment Guidance: The presence of these cells may help establish a patient's prognosis and guide therapeutic strategies.
• Immunotherapy Selection: The biomarker could improve the identification of patients who might benefit from immunotherapy. Currently, immunotherapy is applicable to approximately 5% of colorectal cancer patients and is not effective in all cases.
• Practical Implementation: The biomarker can be detected using immunohistochemistry tests, which are routinely available in hospital pathology services.

Researcher Statements

"The validated marker maintains strong predictive and prognostic performance across patient cohorts."
— Dr. Alexandre Calon

"The identification of CTHRC1 as a TGF-beta-induced factor exemplifies how basic research can lead to clinically applicable biomarkers."
— Dr. Eduard Batlle

"This biomarker improves the selection of patients who could potentially benefit from immunotherapy."
— Dr. Clara Montagut

"The results position CTHRC1(+) CAFs as a useful marker with the potential to be integrated into routine clinical practice."
— Dr. Mar Iglesias

Additional Implications and Future Research

The study notes that the findings could potentially be applicable to other tumor types, such as breast and lung cancer. Researchers also suggest that CTHRC1 could represent a potential therapeutic target for inhibitors, a concept that would require further investigation.