COX-2 expression and its correlation with cyst size in radicular cyst, dentigerous cyst, and odontogenic keratocyst: A comparative immunohistochemical study.

Abstract

Background: Cyclooxygenase-2 (COX-2), an enzyme involved in prostaglandin production, regulates the development of various neoplasms and is often used to assess tumour proliferation.

Aims: We aimed to evaluate the expression of COX-2 in Radicular cysts (RCs), Dentigerous Cysts (DCs) and Odontogenic Keratocysts (OKCs) to determine their proliferative potentials.

Settings and design: Retrospective study.

Methods and materials: Forty-five paraffin-embedded tissue sections, including fifteen cases of each cyst, were stained with the COX-2 antibody. The study recorded the staining intensity and mean degree of immunoreactivity among the three groups. Cyst size was documented from case files and correlated with immunohistochemical scores to examine their relationship with cystic expansion, inflammatory response and COX-2 expression.

Statistical analysis used: Chi-square, ANOVA, post hoc Tukey and unpaired t-test evaluations were performed.

Results: RCs showed the highest immunoreactivity (4.67 ± 0.90), followed by OKCs (4.67 ± 1.35), and DCs (0.53 ± 1.13). The mean degree of immunoreactivity between RC and DC, and OKC and DC, showed significant differences. The intensity and severity of COX-2 staining increased with the cyst size and degree of inflammation. Immunoreactivity scores significantly varied with cyst size (P < 0.01) across all cyst groups.

Conclusions: COX-2 overexpression serves as an inflammatory mediator, encouraging cell proliferation and survival behaviour in RCs and OKCs, ensuring the critical role of COX-2 in the biological activity of cysts and tumours. A combination of COX-2 chemopreventive inhibitors and anti-inflammatory medications may be used to treat odontogenic cysts.