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Ovarian Cancer

Disease Information

Genentech BioOncology is dedicated to advancing the science of ovarian cancer therapy through comprehensive research and education. Ovarian cancer is a malignancy that initiates in the ovaries.¹ Based on the source of origin, ovarian tumors are classified into 3 different categories.²

Epithelial ovarian tumors

Most ovarian tumors are of epithelial origin and arise from cells that cover the outer surface of the ovary.² Ovarian tumors may be benign or malignant in clinical behavior.² Benign epithelial tumors do not spread to distant organs and therefore do not usually cause serious illness.² A number of benign epithelial tumors have been identified that include serous adenomas, mucinous adenomas, and Brenner tumors.²

Malignant epithelial cancers, referred to as carcinomas, constitute ≈85% to ≈90% of epithelial ovarian cancers.²

Based on their unique morphologic features, malignant epithelial ovarian carcinoma tumors may be classified into serous, mucinous, endometrioid, and clear cell subtypes. If the tumor cells do not exhibit any of the 4 morphologic types, they are classified as undifferentiated types; these tumors typically grow and spread more quickly than their differentiated counterparts²
Malignant ovarian epithelial tumors may also include 2 rare subtypes, namely, primary peritoneal carcinoma and fallopian tube cancers.² The latter tumor subtype has a marginally better prognosis than other ovarian cancers²
Ovarian cancers may sometimes include slow-growing tumors of low malignant potential, referred to as borderline epithelial ovarian cancers.² These tumors are less life-threatening than most ovarian cancers and tend to affect women at a younger age²

Ovarian germ cell tumors

Ovarian germ cell tumors typically originate from germ cells that produce the eggs and account for less than 2% of all ovarian cancers.² Most ovarian germ cell tumors are considered benign in nature and are associated with a good prognosis; studies reveal that 90% of patients afflicted with ovarian germ cell tumors survive at least 5 years after initial diagnosis.² Depending upon the morphologic features, ovarian germ cell tumors may be grouped into 5 major categories, namely teratoma, dysgerminoma, endodermal sinus tumor, and choriocarcinoma.²

Ovarian stromal cell tumors

About 1% of ovarian cancers are designated as ovarian stromal cell tumors.² The majority of the stromal tumors are found in women older than 50, with only ≈5% of stromal tumors reported in young girls.² These tumors typically originate from stromal tissue and produce the female hormones estrogen and progesterone.² Based on morphologic features, malignant stromal tumors may be divided into granulosa cell tumors (the most common type), granulosa-theca tumors, and Sertoli-Leydig cell tumors.²

Ovarian Cancer Demographic Statistics

Ovarian cancer ranks second among gynecologic cancers, accounting for an estimated 21,880 new cases in 2010 in the United States³
More deaths result from ovarian cancer than any other malignancy affecting the female reproductive system, accounting for an estimated 13,850 deaths in 2010 in the United States²

Ovarian Cancer Epidemiology

New studies indicate that mutations in BRCA1 and BRCA2 genes may increase ovarian cancer risk²
Other risk factors associated with ovarian cancer include family history of breast and ovarian cancers, estrogen and hormonal therapies, age, obesity, and the use of certain fertility drugs²