The goal of this prospective observational study is to learn more about how a specific type of DNA repair issue-called mismatch repair deficiency (dMMR)-affects colon cancer in people living in Turkey. The study will look at how often dMMR occurs, how it is reported, and how it relates to treatment outcomes.
The main questions it aims to answer are:
* How common is dMMR in colon cancer, and does it vary by where the tumor is in the colon?
* How often is MSI (microsatellite instability) status reported in colon cancer biopsy reports before surgery?
* How do different types of dMMR (such as MLH1/PMS2 loss, MSH2/MSH6 loss, or sporadic cases) affect survival over three years?
Participants will:
* Be people who had surgery for colon cancer between June 1, 2025 and May 31, 2026 at hospitals in Turkey that treat more than 30 colon cancer cases each year.
* Have their medical and pathology data reviewed, including information about tumor location, biopsy results, surgery, and treatment.
This study will not involve any new treatments. Instead, it will use existing medical records to better understand how to improve care and identify people who may benefit from immunotherapy. Results from this study will be shared at scientific meetings and published in medical journals.
Who can participate
Age range
18 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion Criteria:
Patients who have undergone curative-intent surgery for colon adenocarcinoma between June 1, 2025, and May 31, 2026 Surgery performed at a center with \>30 colon cancer surgeries per year Availability of MMR protein immunohistochemistry (IHC) and/or MSI test results from resection specimen and/or preoperative endoscopic biopsy Signed informed consent for participation and data collection
Exclusion Criteria:
Non-adenocarcinoma malignancies of the colon (e.g., neuroendocrine tumors, lymphomas) Rectal cancers (defined as tumors within 15 cm of the anal verge on endoscopy or MRI) Incomplete medical or pathological records preventing classification of MMR status
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Prevalence and Anatomical Distribution of dMMR in Colon Cancer in Turkey
Timeframe: Within 30 days post-operative based on final pathology report
Trial details
NCT IDNCT06971107
SponsorTurkish Society of Colon and Rectal Surgery