Background: Colorectal cancer (CRC) is a common malignancy of the colon and rectum, ranking third globally and second locally. Laboratory-based prognostic evaluation is crucial for reducing CRC incidence and mortality.

Objectives: This study aimed to evaluate tissue expression of Melanoma-associated antigen 3 (MAGE-A3) in CRC patients.

Materials and Methods: Approved by the College of Medicine, Al-Iraqia University, the study was conducted from August 2023 to January 2024. One hundred patients from Medical City and Al-Kadhimiya hospitals, both male and female, with colon and rectal problems participated. Two tissue blocks were obtained from each patient during the study period. Participants were divided into two groups: CRC patients and patients with colorectal problems other than CRC. Immunohistochemistry was used to assess MAGE-A3 tissue expression.

Results: MAGE-A3 expression in CRC tissues was significantly higher compared with the non-CRC group. The difference in expression between CRC and control groups was highly significant (P < 0.001).

Conclusion: MAGE-A3 is a significant marker in CRC, with higher tissue expression in patients than in controls, highlighting its potential as a predictive biomarker for CRC.

Saja Jassim Mohammed, MSc in Microbiology, College of Medicine, Al-Iraqia University, Baghdad, Iraq. Currently works as a pathological analyst. Her research focuses on early cancer detection and diagnostic methods. She has published a research article in a peer-reviewed local scientific journal and submitted another research project in the same field as a patent application for early colorectal cancer diagnosis.