Objective: The aim of this study was to investigate the expression of vascular endothelial growth factor (VEGF) by neoplastic cells in serous ovarian cystadenocarcinoma in relation to proliferation as determined by mitotic activity and to FIGO stage.
Materials and methods: Formalin-fixed, paraffin-embedded archival tissue from 10 benign serous cystadenomas and 45 serous carcinomas was immunostained with a polyclonal antibody to VEGF (Biogenex) utilizing the LSAB kit, alkaline phosphatase (Dako). Positivity was scored as (0) for no, (+) for weak, and (++) for strong staining. Mitotic activity was determined on hematoxylin and eosin stained sections as mitotic figures per 10 high power fields; for carcinomas, three mitotic activity groups (MAG) were established (0-9 = I [N = 13], 10-24 = II [N = 18], >24 = III [N = 14]). The data were analyzed by Fisher's exact test.
Results: In cystadenomas, focal and weak (+) VEGF expression was found in six cases; mitoses were rare. In carcinomas, no significant difference of (+) and (++) staining intensity was found between MAG I and II (P = 0.6239). In MAG II, focal (++) staining was frequently observed on a background of (+). (++) staining was significantly more frequent in MAG III compared with MAG II (P = 0.0027). Diffuse (++) was more common in MAG III than in MAG II (P = 0.0062). FIGO III cases displayed more frequently a diffuse (++) staining than the FIGO I and FIGO II cases taken together (P = 0.0017).
Conclusion: VEGF expression as determined by immunohistochemistry is related to high mitotic activity and high FIGO stage in serous ovarian cystadenocarcinomas. VEGF expression seems to be an interesting indicator of neoplastic proliferation and may offer therapeutic options for these cancers.