Expression of interleukin-6 in ocular surface squamous neoplasia

Abstract

Purpose

Interleukin-6 (IL-6) is an important cytokine in the cascade of inflammation and cancer progression. The aim of this study was to identify IL-6 expression in ocular surface squamous neoplasia (OSSN) in comparison with non-neoplastic conjunctival tissue.

Methods

Twenty paraffin-embedded tissue sections of conjunctiva from patients with OSSN including conjunctival intraepithelial neoplasia (CIN) in all grades of severity and squamous cell carcinoma (SCC) were assessed by immunohistochemistry staining for IL-6. Twenty non-neoplastic conjunctival sections from age matched patients were selected as the control group. Tissues with more than one focus of inflammatory cell infiltration were excluded from the study. The mean area of positive staining was recorded and the intensity of staining was scored in both groups and compared by statistical methods.

Results

The mean staining area in the dysplasia group was significantly more than non-neoplastic conjunctival tissue (63.5±25.96 and 30±15.98 percent respectively; P-value of <0.0001). Nuclear staining was observed in both groups and the difference was not statistically significant.

Conclusion

IL-6 expressed more in the dysplastic group in compare to non-neoplastic conjunctiva and can therefore be used to diagnose dysplastic state of the conjunctiva; however, in our study, intensity of staining does not correlate with the severity of dysplasia statistically; most probably because of a low sample size in each category. The role of nuclear staining is not clear. Our findings can be an introduction toward targeted treatment of ocular surface neoplasia by the aim of newer anti-IL agents. Further investigation is needed.

Keywords:

• interleukin-6
• squamous cell carcinoma
• dysplasia
• conjunctival intraepithelial neoplasia

Abbreviations

IL, Interleukin; OSSN, Ocular surface squamous neoplasia; CIN, Conjunctival intra epithelial neoplasia.

Acknowledgment

We would like to thank Dr. Negar Azarpira at the Pathology Department and Ms. Hakimzadeh for their help, and Ms Tayyebe Shabanian for technical support in slide preparation and interpretation. Also, the authors wish to thank Mr. H. Argasi at the Research Consultation Center (RCC) of Shiraz University of Medical Sciences for his invaluable assistance in editing this manuscript. The present article is extracted from the thesis written by Vahid Beigi, MD under the supervision of Dr. Masoomeh Eghtedari which was funded by a grant from Shiraz University of Medical Sciences [No. 8977].

Disclosure

All authors declare that they have no conflicts of interest in this work.