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Retrospective Study
Copyright ©The Author(s) 2025. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Oncol. Sep 24, 2025; 16(9): 109182
Published online Sep 24, 2025. doi: 10.5306/wjco.v16.i9.109182
Lynch syndrome association and clinicopathological features in early-onset colorectal cancers: A single-center retrospective study
Yunus Sür, Emine Özlem Gür, Fevzi Cengiz, Aslı Subaşıoğlu, İsmail Güzeliş, Sinem Demir, Aysegul Akder Sari, Mehmet Haciyanli, Osman Nuri Dilek
Yunus Sür, Emine Özlem Gür, Fevzi Cengiz, Mehmet Haciyanli, Osman Nuri Dilek, Department of General Surgery, İKÇÜ Atatürk Education and Research Hospital, İzmir 35150, Türkiye
Aslı Subaşıoğlu, Department of Genetic, İKÇÜ Atatürk Education and Research Hospital, İzmir 35150, Türkiye
İsmail Güzeliş, Sinem Demir, Aysegul Akder Sari, Department of Pathology, İKÇÜ Atatürk Education and Research Hospital, İzmir 35150, Türkiye
Author contributions: Sür Y wrote the manuscript; Sür Y, Cengiz F, Sari AA, Haciyanli M, and Dilek ON participated in the conception and design of the study and were involved in the acquisition, analysis, or interpretation of data; Gür EÖ, Subaşıoğlu A, Güzeliş İ, and Demir S accessed and verified the study data; all authors critically reviewed and provided final approval of the manuscript, were responsible for the decision to submit the manuscript for publication.
Institutional review board statement: The study was reviewed and approved by the İzmir Katip Celebi University Non-Interventional Clinical Studies Institutional Review Board.
Informed consent statement: All study participants, or their legal guardian, provided informed written consent prior to study enrollment.
Conflict-of-interest statement: The authors declare that they have no conflicts of interest regarding the publication of this paper, including but not limited to commercial, personal, political, intellectual, or religious interests.
Data sharing statement: The data supporting the findings of this study are available from the corresponding author upon reasonable request. Due to the sensitive nature of the data and to protect patient privacy, they are not publicly available. However, participants provided written informed consent for data sharing under appropriate conditions.
Open Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Yunus Sür, MD, General Surgeon, Department of General Surgery, İKÇÜ Atatürk Education and Research Hospital, Basın Sitesi, İzmir 35150, Turkey. dr.yunus.sur@gmail.com
Received: May 6, 2025
Revised: May 25, 2025
Accepted: August 8, 2025
Published online: September 24, 2025
Processing time: 144 Days and 22.3 Hours
Abstract
BACKGROUND

Hereditary factors are more prevalent in early-onset colorectal cancers (EOCRC) etiology. Lynch syndrome (LS) is the most common hereditary colorectal cancer (CRC) syndrome that results from mutations in DNA mismatch repair (MMR) genes. This phenomenon is defined as microsatellite instability (MSI). Immunohistochemistry (IHC) is a widely used, practical, and cost-effective method for the screening of MSI. However, using IHC alone may be insufficient to identify patients with MSI and LS.

AIM

To determine the clinicopathological features in EOCRC, IHC performance, and the frequency of genetic testing for EOCRC patients.

METHODS

A retrospective review was conducted on patients with CRC aged ≤ 50 years who underwent surgery at our center between January 2014 and July 2021. MMR proteins were screened using IHC. Of the 131 patients included, IHC was performed on 130. Patients were classified as MSI or microsatellite-stable (MSS), and their features were compared. Additionally, data from patients who received genetic counseling were analyzed.

RESULTS

Thirty patients with MSI were designated as group 1, whereas 100 with MSS were defined as group 2. The mean age in group 1 was the lowest (median age: 42 vs 46, P < 0.05). Group 1 exhibited a higher frequency of tumors in the right colon and a lower frequency in the rectum. Lymph node involvement and distant metastases were less common in group 1, and in group 2, tumors were generally diagnosed at a more advanced stage. Genetic testing was performed in 53 patients (40%), with a definitive LS diagnosis established in 13/17 patients (76.4%) in group 1 and 1/36 (2.7%) patients in group 2, resulting in a total of 14 patients (26.4%) with confirmed LS.

CONCLUSION

MSI tumors show a better prognosis. IHC is very effective for screening MSI, but may not be sufficient alone. Low genetic counseling rates highlight the need for hospital-based surveillance programs.

Keywords: Early-onset colorectal cancer; Immunohistochemistry; Lynch syndrome; Microsatellite instability; Mismatch repair

Core Tip: Lynch syndrome (LS) results from microsatellite instability (MSI). Immunohistochemistry (IHC) is a cost-effective and practical method for MSI screening. This retrospective study evaluated clinicopathological features of MSI and microsatellite-stable (MSS) tumors in early-onset colorectal cancer patients between 2014 and 2021. MSI tumors were linked to younger age, right-sided location, and fewer metastases. Genetic testing confirmed LS in 76.4% of MSI and 2.8% of MSS cases based on IHC. However, 59.5% of patients did not receive genetic counseling. While IHC is useful for MSI detection, it may not be sufficient alone. Low counseling rates emphasize the need for hospital-based surveillance programs.