Evaluation of tumor angiogenesis and thymidine phosphorylase tissue expression in patients with endometrial cancer

The formation of new blood vessels in endometrial cancer tissue is a main process, which leads to tumor progression, and is connected with tumor expansion and invasiveness. The aim of the study was evaluation of thymidine phosphorylase protein (TP) expression in human endometrial cancer cells by immunohistochemistry and comparison obtained data with intensity of angiogenesis process and clinicopathological factors as FIGO stage of disease and histopathologic grade. Endometrial cancer specimens were obtained from 55 postmenopausal patients (aged 52 to 74 years) underwent total abdominal hysterectomy with bilateral salpingo-oophorectomy. None of patients received preoperative pelvic irradiation. Histopathological typing and grading of the endometrial tumors (G-1, G-2, G-3) as well as myometrial invasion (<1/2, >1/2) were assessed using standard criteria, on hematoxylin-eosin sections. At the surgery, FIGO clinical stage of disease was determined. Thymidine phosphorylase overexpression was observed in 23 of 55 (41.8%) cases of endometrial cancer. Although we found no statistically significant differences in TP expression between histopathologic grades, particular FIGO stages showed a significant trend of increase TP tumor overexpression. Thymidine phosphorylase overexpression cases demonstrate higher intensity of angiogenesis in comparison to negative samples and results are statistically significant for t-test (p<0.0001). The most intensive new blood vessel formation was observed in G-2 of tumor differentiation grade (p=0.013 for ANOVA test) Mean angiogenic points density (APD) values in cases of G-1 histopathologic grade reached 135.7; values of G-2 and G-3 grades reached 213.8 and 162.8, respectively. Mean intensity of angiogenesis in the first FIGO stage of disease reached 160.0 APD, in stage II 205.6 APD, and in the third 286.9, respectively. Angiogenesis was more intensive in cases of advanced tumors - analysis of variance (ANOVA) confirmed statistically significant differences in APD values between FIGO stage groups (p=0.0007). In conclusion, thymidine phosphorylase expression correlates with increased microvessel density in endometrial cancer. The intensity of angiogenesis process increases according to FIGO stage of disease, which is connected with progressing of cancer disease. Thymidine phosphorylase can play an important role in endometrial cancer progression and could offer additional information about advance of disease.