The Importance of Immunohistochemical Heterogeneous Expression of MMR Protein in Patients with Colorectal Cancer in Stage II and III of the Disease

• Published in: Medicina (Kaunas, Lithuania) Vol. 59; no. 3; p. 489
• Main Authors: Denčić, Tijana, Petrović, Aleksandar, Jovičić Milentijević, Maja, Radenković, Goran, Jović, Marko, Živković, Nikola, Šalinger, Sonja, Branković, Branko, Veličkov, Aleksandra, Ilić, Ivan
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01-03-2023; MDPI
• Subjects: Adaptor Proteins, Signal Transducing; Analysis; Care and treatment; Chemotherapy; Classification; Colectomy; Colorectal cancer; Colorectal Neoplasms - pathology; Diagnosis; heterogeneous nuclear expression; Humans; immunohistochemical analysis; Immunohistochemistry; Localization; Lymphatic system; Metastasis; Microsatellite instability; mismatch repair protein; MutL Protein Homolog 1 - metabolism; Neoplasm Staging; Patient outcomes; Protein expression; Proteins; Regression analysis; Tumors; Serbia; Denmark; heterogeneous nuclear expression; mismatch repair protein; colorectal cancer; immunohistochemical analysis
• ISSN: 1648-9144; 1010-660X; 1648-9144
• DOI: 10.3390/medicina59030489

: In patients with colorectal cancer (CRC), heterogeneous expression of Mismatch repair (MMR) proteins can manifest itself in several different forms and is not such a rare phenomenon. Therefore, it is very important to recognize the nuclear expression of MMR proteins of different MMR status in order to avoid false positive or false negative results. The aim of this study was to determine the frequency and distribution of heterogeneous expression of MMR proteins in patients with stages II and III of the disease as well as its association with clinical, demographic and pathological characteristics of CRC in relation to proficient and deficient expression of MMR proteins.
: The study included 104 cases of colorectal cancer obtained from surgical colectomy material in stages II and III of the disease.
From a total of 104 patients with colorectal cancer, immunohistochemical analysis of the expression of all four MMR proteins showed that heterogeneous expression of MMR proteins (as well as deficient immunoreactivity of tumor cells) was present in 12 cases, while proficient expression of MMR proteins was detected in 80 tumors.
: Our study showed that the only independent predictors of the loss of MMR protein expression were younger patient age and right-sided anatomical location of the tumor. The study also established the existence of heterogeneous expression of MMR proteins in a non-negligible percentage of CRCs (11.5%), where heterogeneous nuclear expression of MMR proteins was described in several different forms.