This interventional cohort study will evaluate circulating tumor DNA (ctDNA) and tumor-educated platelets (TEP) as blood-based biomarkers in adults with stage III colon cancer who are planned to receive neoadjuvant systemic therapy followed by surgical resection. Treatment will be given according to routine clinical practice and will depend on the biological characteristics of the tumor, including mismatch repair status. Participants will provide additional blood samples at predefined time points before, during, and after treatment and surgery. These samples will be used to analyze ctDNA and TEP and to assess whether changes in these biomarkers are associated with radiological response, pathological response, and disease-free outcomes. Approximately 80 participants will be enrolled at the Institute of Oncology Ljubljana. Participants will not receive experimental drugs as part of this study.
This is a prospective interventional longitudinal cohort study of adult patients with histologically confirmed stage III colon adenocarcinoma who are planned to receive neoadjuvant systemic therapy followed by surgical resection with curative intent. The study will evaluate the dynamics of circulating tumor DNA (ctDNA) and tumor-educated platelets (TEP) during neoadjuvant treatment and follow-up. Neoadjuvant systemic therapy will be selected according to routine clinical practice and tumor biology, including mismatch repair status. Patients with pMMR tumors may receive chemotherapy, while patients with dMMR tumors may receive immunotherapy, according to standard clinical decision-making. The research intervention consists of additional peripheral venous blood sampling at predefined time points before treatment, during systemic treatment, before surgery, and after surgery. Blood samples will be analyzed for ctDNA and TEP-based biomarkers. Clinical, radiological, pathological, and follow-up data will be collected from routine medical documentation. The primary objective is to determine whether the presence of ctDNA after completion of neoadjuvant systemic therapy is associated with pathological tumor response, defined as major pathological response (MPR), in patients with stage III colon cancer. Secondary and exploratory objectives include evaluation of the association between ctDNA, TEP profiles, radiological response, recurrence-free outcomes, and disease-free outcomes. Approximately 80 participants will be enrolled. The study is academic and non-commercial. Participants will not receive experimental drugs as part of this study, and all therapeutic and diagnostic procedures will follow established clinical practice.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
DIAGNOSTIC
Masking
NONE
Enrollment
80
Additional peripheral venous blood samples will be collected at predefined time points before treatment, during systemic treatment, before surgery, and after surgery. Samples will be analyzed for circulating tumor DNA (ctDNA) and tumor-educated platelets (TEP).
Institute of Oncology Ljubljana
Ljubljana, Slovenia
Percentage of Participants With Major Pathological Response in the Post-Neoadjuvant ctDNA Assessment
Major pathological response will be assessed by histopathological evaluation of the surgical resection specimen after completion of neoadjuvant systemic therapy. The unit of measure will be the percentage of participants with major pathological response. ctDNA status after completion of neoadjuvant systemic therapy will be used as a pre-specified stratification variable in the statistical analysis.
Time frame: From completion of neoadjuvant systemic therapy to pathological assessment after surgical resection, approximately 3 to 6 months.
Percentage of Participants With Objective Radiological Response According to RECIST 1.1
Radiological response will be assessed according to RECIST version 1.1 using routine preoperative imaging. Objective radiological response will include complete response and partial response. The unit of measure will be the percentage of participants with objective radiological response. ctDNA status after completion of neoadjuvant therapy will be used as a pre-specified stratification variable in the statistical analysis.
Time frame: From baseline to preoperative radiological assessment, approximately 3 to 6 months.
Percentage of Participants Alive and Disease-Free at 12 Months After Surgical Resection
Disease-free status will be assessed using routine clinical, radiological, and follow-up documentation. The outcome will be defined as being alive and without disease recurrence at 12 months after surgical resection. The unit of measure will be the percentage of participants alive and disease-free at 12 months. ctDNA status after completion of neoadjuvant therapy will be used as a pre-specified stratification variable in the statistical analysis.
Time frame: 12 months after surgical resection.
Percentage of Participants With Early Disease Recurrence Within 12 Months After Surgical Resection in the Postoperative ctDNA Assessment
Early disease recurrence will be assessed using routine clinical, radiological, and follow-up documentation. The unit of measure will be the percentage of participants with disease recurrence within 12 months after surgical resection. Postoperative ctDNA status will be used as a pre-specified stratification variable in the statistical analysis.
Time frame: Up to 12 months after surgical resection.
Percentage of Participants With Early Disease Recurrence Within 12 Months After Surgical Resection in the Postoperative TEP Assessment
Early disease recurrence will be assessed using routine clinical, radiological, and follow-up documentation. The unit of measure will be the percentage of participants with disease recurrence within 12 months after surgical resection. Postoperative tumor-educated platelet status will be used as a pre-specified stratification variable in the statistical analysis.
Time frame: Up to 12 months after surgical resection.
Percentage of Participants With Major Pathological Response in the Baseline ctDNA Assessment
Major pathological response will be assessed by histopathological evaluation of the surgical resection specimen. The unit of measure will be the percentage of participants with major pathological response. Baseline ctDNA status will be used as a pre-specified stratification variable in the statistical analysis.
Time frame: From baseline to pathological assessment after surgical resection, approximately 3 to 6 months.
Percentage of Participants With Pathological Complete Response After Surgical Resection
Pathological complete response will be assessed by histopathological evaluation of the surgical resection specimen. The unit of measure will be the percentage of participants with pathological complete response. Baseline ctDNA status will be used as a pre-specified stratification variable in the statistical analysis.
Time frame: From baseline to pathological assessment after surgical resection, approximately 3 to 6 months.
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.