**1. Introduction**

Epithelial ovarian cancer is the second most common gynecological cancer. It causes more deaths despite advances in treatment over the last few decades.

Epithelial ovarian cancer is the most common histological subtype diagnosed, accounting for 80% of cases [1]. It arises from the coelomic epithelium, 75% are serous cystadenocarcinoma, other types are less frequent and include endometrioid, mucinous, Brenner transitional cell, clear cell and unclassified carcinomas. Germ cell and sex cord-stromal tumors represent the other 20% [1].

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
