Abstract
Purpose :
The biomarkers p63 and SOX are expressed in squamous cell carcinoma of different localization, where their presence seems to be linked to tumor progression. The expression of these markers in conjunctival SCC (CSCCs) has not been studied so far. This study examines the expression of p63, SOX2 and the conjunctival cytokeratin K19 in CSCCs in relation to clinical data of the patients in order to evaluate the prognostic value of the markers for CSCCs.
Methods :
In total 65 paraffin-embedded samples of CSCCs, confirmed by pathological examination, were analyzed. Samples were stained immunhistologically for p63, SOX2 and K19. The intensity of the staining signal and the percentage of positive cells were determined by a pathologist afterwards the immunoreactive score (IRS) of each marker was calculated for every sample. The IRS was classified as either weak, moderate or strong. It was aligned to the severity of the malignancy.
Results :
24% of all samples showed a positive staining for K19, 49% were positive for SOX2 and 94% were positive for p63 with IRS scores including all degrees. In 14 patients orbital exenteration was required. In 8 eyes of them the IRS score revealed a simultaneous expression of SOX2 and p63. In two notable cases of the exenterations, one where infiltration of the globe and metastasis of the lymph nodes and one where aggressive relapse and bulbar infiltration occurred, tumor samples displayed a strong simultaneous IRS score for SOX2 and p63. K19 was detected in 6 enucleated eyes. The remaining 51 eyes could be saved. They displayed expression of the three markers of various intensities. A co-expression of SOX2 and p63 in the sustained eyes occurred in 16 eyes. There was no statistically significant connection between the IRS of the different markers, neither the of a single marker nor of a combination of markers, and the clinical outcome.
Conclusions :
The high overall number of K19 negative samples might be associated with the loss of regular differentiation status in CSSCs leading to an overall loss of epithelial differentiation markers. The prominence of p63 in the samples is a regular sign of SCC progression. SOX2 expression is less frequent in CSSCs than p63. Although a simultaneous expression of p63 and SOX2 was noticed more in prominent CSSCs compared to less aggressive tumors there is no significant correlation between the IRS of the markers and clinical tumor development .
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.