Objectives: The main aim of the study was to evaluate the impact of levels of serum soluble receptor-binding cancer antigen expressed on SiSo cells (sRCAS1) on the overall survival (OS) rates in patients with endometrial cancer. Furthermore, we analyzed sRCAS1 levels according to the clinicopathological characteristics of the disease.
Material and methods: The study group comprised 43 patients who were being treated for endometrial cancer. We included 10 low-risk, 20 intermediate-risk and 13 high-risk endometrial cancers using the criteria of the European Society for Medical Oncology (ESMO), the European Society for Radiotherapy & Oncology (ESTRO) and the European Society of Gynaecological Oncology (ESGO). Serum sRCAS1 levels were obtained before and after surgery. Serum sRCAS1 levels were assessed using the ELISA method.
Results: In our univariate analysis, both the pre- and post-surgery high sRCAS1 groups of patients with endometrial cancer indicated a shortened OS. However, in our multivariate analysis, when patients' age and disease-related risk was taken into consideration, only the post-surgery sRCAS1 levels remained as independent prognostic factors of a poor OS. Pre-treatment serum sRCAS1 levels were statistically significantly higher than post-surgery sRCAS1 levels; however, the difference between pre- and post-surgery sRCAS1 levels did not influence the patients' OS rate. Pre- and post-surgery sRCAS1 levels did not differ according to tumor grade, stage of the disease or the disease-related risk group.
Conclusions: High post-surgery serum sRCAS1 levels seem to be an independent indicator of shortened overall survival in patients with endometrial cancer.
Keywords: RCAS1; cancer immunology; endometrial cancer; receptor-binding cancer antigen expressed on SiSo cells; sRCAS1.