Prognostic Significance of Microsatellite Instability in Turkish Patients with Stage II and III Colorectal Cancer
Adem Deligonul1, Nilufer Avci2, Meral Kurtul3, Sebnem Ozemri Sag4, Ozgen Isik5, Merve Hafizoglu6, Emre Hafizoglu6, Birol Ocak1, Ahmet Bilgehan Sahin1, Sibel Oyucu Orhan1, Erdem Cubukcu1, Turkkan Evrensel11Department of Medical Oncology, Uludag University Faculty of Medicine, Bursa, Turkey, 2Department of Medical Oncology, Medicana Hospital Bursa, Turkey, 3Department of Radiation Oncology, Uludag University Faculty of Medicine, Bursa, Turkey, 4Department of Medical Genetics, Uludag University Faculty of Medicine, Bursa, Turkey, 5Department of General Surgery, Uludag University Faculty of Medicine, Bursa, Turkey, 6Department of Internal Medicine, Uludag University Faculty of Medicine, Bursa, Turkey
Objectives: Microsatellite instability (MSI) – a form of pervasive erratic expansion of microsatellites – can be identified in 15?20% of all patients with sporadic colorectal cancer (CRC). To gain further insight into the prognostic value of MSI in CRC, we sought to investigate this issue in a nonselected sample of Turkish patients seen in daily practice and to establish whether the MSI status is associated with survival outcomes. We specifically focused on patients with stage 2 and stage 3 CRC because they are a heterogeneous group in need of an improved clinical management. Methods: A total of 81 patients were enrolled into the study. MSI analysis was performed a dedicated platform and classified into three types, as follows: microsatellite stability (MSS), low microsatellite instability (MSI-L), and high microsatellite instability (MSI-H). Disease-free survival (DFS) and overall survival (OS) served as the main outcome measures. Results: Patients with MSI-H had a significantly higher frequency of right colon tumors compared with those with MSI-L/MSS. Moreover, no cases of rectal tumor were observed in the former group (p=0.002). As a result, the use of radiotherapy was limited to patients with MSI-L/MSS (p=0.02). Patients with MSI-H did not differ from those with MSI-L/ MSS both in terms of DFS and OS. Conclusion: Our study demonstrates that Turkish patients with proximal colon cancer more frequently have MSI-H compared to those with distal colon cancer. However, the MSI status did not have a significant impact on survival outcomes. Keywords: Colorectal cancer, microsatellite instability, survival, tumor sidedness
Cite This Article
Deligonul A, Avci N, Kurtul M, Sag S, Isik O, Hafizoglu M, Hafizoglu E, Ocak B, Sahin A, Oyucu Orhan S, Cubukcu E, Evrensel T. Prognostic Significance of Microsatellite Instability in Turkish Patients with Stage II and III Colorectal Cancer. EJMI. 2021; 5(1): 62-66
Corresponding Author: Adem Deligonul