Introduction: Colorectal cancer is the third most important cancer in men and the second in women. It is one of the main causes of cancer deaths, which survive about 2 percent of patients about 5 years after the onset of the disease. The HE4 protein is secreted in the distal epithelium, which has an effect as a proteinase inhibitor in the puberty of sperm. HE4 has a diagnostic value in various cancers, including colorectal cancer. This study was aimed at examining the HE4 tumor in patients with colorectal cancer before and after treatment.

Methods: This study was conducted on 77 patients with colorectal cancer hospitalized in Amir, mother and child hospitals and Shiraz Faghih Hospital. Patients were investigated in terms of the HE4 marker level and the urine with the Eliza method. Patients' clinical and pathological data were collected. SPSS 24 software was used for data analysis.

Results: A total of 77 participants entered this study. The mean age of the participants was 59.34 ± 12.143 years and 45 participants (58.4%) were male and 32 (41.6%) were female. The mean serum level of HE4 in patients before treatment was 69.91 ± 83.518 pmol/lit, while serum HE4 level after treatment reached 76.95 ± 65.142 pmol/lit. although these two variables did not differ significantly, they were directly correlated (r=0.622, and p=0.031). post-treatment serum HE4 level did not differ significantly between the first and second groups. Pre-treatment HE4 was the only affecting variable in post-treatment HE4, and age, sex, surgical interventions, and chemotherapy did not affect the post-treatment serum level of HE4.

Conclusion: This study provides valuable information on the relationship between pre- and post-treatment levels of HE4 in patients with colorectal cancer. The findings suggest that pre-treatment HE4 may be a useful marker for predicting post-treatment levels, and that treatment may have an impact on HE4 levels in the body.