Ovarian neoplasms consist of several histopathologic entities, and treatment depends on the specific tumor type. Epithelial ovarian cancer comprises most malignant ovarian neoplasms (∼ 80%) 1; however, other less-common pathologic subtypes must be considered in treatment guidelines. The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Ovarian Cancer discuss epithelial ovarian cancer (including borderline or low malignant potential) and less-common histopathologies, including malignant germ cell neoplasms, carcinosarcomas (malignant mixed Müllerian tumors of the ovary [MMMT]), and sex cord-stromal tumors. The guidelines also discuss fallopian tube and primary peritoneal cancers, which are less-common neoplasms that are managed similarly to epithelial ovarian cancer. However, the less-common histologies of ovarian cancer are managed differently. Information on the less-common ovarian histopathologies are not published in this issue of JNCCN, but can be found online at www. NCCN. org.

Epithelial ovarian cancer is the leading cause of death from gynecologic cancer in the United States and the country's fifth most common cause of cancer mortality in women. In 2010, an estimated 21,900 new diagnoses and 13,900 deaths will occur from this neoplasm in the United States; fewer than 40% of women with ovarian cancer are cured. 2, 3 The incidence of ovarian cancer increases with age and is most prevalent in the eighth decade of life, with a rate of 57 per 100,000 women. The median age at diagnosis is 63 years, and 70% of patients present with advanced disease. 4