Evaluating the expression of cyclooxygenase-2 enzyme by immunohistochemistry in normal and tumoral tissue before and after neoadjuvant chemoradiotherapy in patients with esophageal cancer in Khorasan Province

Background

Esophageal cancer is the third most common cancer in Iran. Neoadjuvant chemoradiotherapy (NCRT) is the appropriate treatment for esophageal cancer.

Aim

This study investigated the expression of cyclooxygenase (COX)-2 enzyme in normal and tumoral tissues before any treatment in patients with esophageal cancer, this study also assessed the effect of NCRT on the expression of COX-2 enzyme in normal and tumoral tissue in samples derived by surgery furthermore, and this study investigated the relationship between expression of COX-2 enzyme and the pathologic tumor regression grade (PTRG) patients.

Materials and Methods

In this study, a total of 120 patients admitted to Omid Hospital, Imam Reza Hospitals, and Reza-Mashhad Medical Center, who were treated with NCRT, were recruited and the expression of the COX-2 enzyme in normal and tumoral tissues was assessed by immunohistochemistry before and after treatment by an expert pathologist between zero and 300. PTRG was determined by a pathologist after treatment.

Results

The mean levels of COX-2 expression, obtained from tumoral and normal tissue baseline biopsy in patients, were 177.69 and 64.29, respectively, while in surgical specimen were 177.25 and 49.84, respectively. A significant association was found between PTRG of surgical specimen and COX-2 expression in normal tissue (baseline biopsy) at diagnosis (P = 0.034).

Conclusions

The results indicated that expression of COX-2 in tumoral tissues exceeds the expression of COX-2 in normal tissue of the baseline biopsy. Patients with a high expression of COX-2 in baseline tumor biopsies had less response to treatment of pathology compared to patients with lower expression of COX-2 in baseline tumor biopsies.