MOCA MINNESOTA OVARIAN CANCER ALLIANCE

Ovarian cancer is a growth of abnormal malignant cells that begins in the ovaries. Cancer that spreads to the ovaries but originates at another site is not considered ovarian cancer.

Ovarian tumors can be benign (noncancerous) or malignant (cancerous). Although abnormal, cells of benign tumors do not metastasize (spread to other parts of the body).

Malignant cancer cells in the ovaries can metastasize in two ways: Directly to other organs in the pelvis and abdomen (the more common way), and also through the bloodstream or lymph nodes to other parts of the body.

Ovarian cancer accounts for approximately 3 percent of cancers in women. It is only the ninth most common cancer among women, but ovarian cancer is the fifth leading cause of cancer-related death among women, and it is the deadliest of gynecologic cancers. Mortality rates are slightly higher for Caucasian women than for minority women.

Ovarian Cancer Risk by the Numbers

• A woman’s lifetime risk of developing invasive ovarian cancer is 1 in 71.
• A woman’s lifetime risk of dying from invasive ovarian cancer is 1 in 95.
• Ovarian cancer primarily develops in women over 45; however it does occur in young women as well.
• From 2002 to 2006, the median age at diagnosis was 63. From 2002 to 2006, the median age at death from ovarian cancer was 71.

Ovarian Cancer Survival Rates

Ovarian cancer survival rates are much lower than other cancers that affect women.

• Overall, the 10-year relative survival rate for ovarian cancer patients is 39 percent.
• The relative five-year survival rate is 46 percent. Survival rates vary depending on the stage of diagnosis.
• Women diagnosed at an early stage have a much higher five-year survival rate than those diagnosed at a later stage.
• Fewer than 20 percent of ovarian cancer patients are diagnosed early.
• Survival rates for ovarian cancer continue to improve! Women diagnosed with ovarian cancer in 1975 experienced a five-year survival rate of 34.8 percent; today, the American Cancer Society estimates the rate to be 46 percent.

Types of Ovarian Cancer

Different types of ovarian cancer are classified according to the type of cell from which they arise.

Epithelial ovarian carcinoma

Prevalence of Various Epithelial Ovarian Cancer Types

Epithelial ovarian carcinoma is the most common type of ovarian cancer, and arises from the cells covering the surface of the ovaries (epithelial cells). This type accounts for 85-90% of ovarian cancer cases. Epithelial ovarian carcinomas include the following types:

• Serous – the most common type of epithelial ovarian cancer.  The term “serous” refers to serum, the clear liquid part of the blood.
• Endometrioid – the second most common type of epithelial ovarian cancer.  The term “endometrioid” refers to the lining of the uterus.  In some cases, endometrioid carcinomas of the ovary appear together with an endometrial carcinoma (epithelial cancer of the uterus) and/or endometriosis (presence of endometrial tissue outside the uterus)
• Undifferentiated – the cells of this type of tumor do not share characteristics with any specific type of ovarian tissue cells
• Borderline tumors – cells have characteristics of both benign (non-cancerous) and malignant (cancerous) tissue.
• Clear cell – this type of ovarian cancer gets its name because the center of the cells appear clear when viewed through a microscope.
• Mucinous – most commonly found in early stages, these tumors often present as large pelvic or abdominal masses.

Germ cell carcinoma tumor

This type makes up about five percent of ovarian cancer cases, and begins in the cells that form eggs. While germ cell carcinoma can occur in women of any age, it tends to be found most often in women in their early 20s. Six main kinds of germ cell carcinoma exist, but the three most common types are: teratomas, dysgerminomas, and endodermal sinus tumors. Many tumors that arise in the germ cells are benign.

Germ cell cancers usually grow rapidly. They can become very large and cause significant pain or abdominal distension. Some germ cell cancers may produce the pregnancy hormone HCG. This can lead to a false positive pregnancy test.

For more detailed information about germ cell ovarian oancer, see these pages on the National Cancer Institute or the Women’s Cancer Network websites.

Stromal carcinoma tumors

Ovarian stromal carcinoma accounts for about five percent of ovarian cancer cases. It develops in the connective tissue cells that hold the ovary together and those that produce the female hormones estrogen and progesterone. The two most common types are granulosa cell tumors and sertoli-leydig cell tumors. Unlike epithelial ovarian carcinoma, 70 percent of stromal carcinoma cases are diagnosed in Stage I.

Stromal cell cancers are usually slow growing. They can cause pain and discomfort in the early stages. These cancers are known to secrete hormones like estrogen or testosterone. The effects of these hormones include:

• abnormal uterine bleeding
• new onset acne
• facial hair growth

For more detailed information about stromal carcinoma tumors, visit these pages on the Johns Hopkins Pathology or the Women’s Cancer Network websites.

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Our Sources

Ovarian Cancer National Alliance