Evaluation of the contribution of COX-2 to the diagnostic and its relationship with clinicopathological parameters among kaposi's sarcoma and imitative lesions

Aim: In this study, it was mainly aimed to investigate whether there is a difference in immune expression of cyclooxygnease-2 (COX-2) between Kaposi sarcoma (KS) and mimicry lesions, and secondly, to determine the relationship of COX-2 expression with clinical and hematological parameters. Materials and Methods: In our study, 37 patients diagnosed with KS, whose biopsy samples were taken at Düzce University Medical Faculty Hospital between 2012 and 2021, and 37 cases that were mixed with KS in the differential diagnosis and studied human herpes virus-8 (HHV-8) immunohistochemically were included in our study. Cases with pathological diagnosis of KS and optimally stained sections with COX-2 and CD34 stains were included in the study. Our hospital database information system was used to collect data on demographic and clinical information of patients. Age, gender, hemogram parameters (leukocyte, neutrophil, lymphocyte, mean platelet volume (MPV)), urea and creatinine values of the patients were recorded, neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (TLR) were calculated. HHV-8, CD34 and COX-2 protein amounts were evaluated by histochemical examination by preparing sections from paraffin-embedded skin samples in the archive of all patients included in the study. Results: Male/female ratio and median age were found to be statistically significantly higher in KS patients compared to the control group (respectively; p=0.018, p<0.001). According to the histological progression stages of KS patients; 19 (51.4%) were at tumor stage, 8 (21.6%) were at plaque stage, and 10 (27.0%) were at patch stage. HHV-8 immunoreactivity was observed in all (100%) patients with KS. COX-2 immunoreaction in a cytoplasmic diffuse pattern was observed in 33 (89.2%) of the KS patients and 16 (43.2%) of the control group. A significant difference was found between the KS and control groups in terms of COX-2 and CD34 staining degrees (p<0.001, p<0.001, respectively). There was a significant difference in CD34 staining grade between lesion stages (tumor, plaque, patch) in KS patients (p<0.001) but no significant difference was found in COX-2 staining grade (p=0.728). In KS patients, NLR and TLR values were found to be significantly higher in the group with high COX-2 staining than in the group with low COX-2 staining (respectively; p=0.002, p=0.016). The HHV-8 score of KS patients in the tumor stage was found to be significantly higher than the HHV-8 score of the patients in the patch stage (p=0.036). Conclusions: It was concluded that COX-2 plays an important role in the development of KS and can be used for diagnostic purposes in addition to HHV-8, CD34, which is used in the differential diagnosis of KS. In addition, COX-2 overexpression was found to be correlated with higher NLR and TLR, which is characterized by inflammation. These findings were thought to be important in terms of the pathogenetic process of KS and the prognosis of the tumor. Studies supported by larger series and further molecular and genetic studies are needed to support our findings. KEYWORDS: Kaposi sarcoma, COX-2, HHV-8, CD34, immunohistochemistry