Ovarian Cancer

http://our-medical-center.blogspot.com/2007/12/ovarian-cancer.html

Ovarian cancer is cancer that begins in the ovaries. In women, the ovaries produce eggs (ova) for reproduction. The eggs travel through the fallopian tubes into the uterus where the fertilized egg implants and develops into a fetus. Cancer can also begin in the fallopian tubes. The ovaries are also the main source of the female hormones estrogen and progesterone. One ovary is located on each side of the uterus in the pelvis.

The ovaries contain 3 kinds of tissue.

Germ cells, which produce eggs (ova) that are formed on the inside of the ovary. Each month from puberty until menopause women normally produce an egg that makes its way to the surface, where it is shed into the fallopian tube.

Stromal cells, which produce most of the female hormones estrogen and progesterone.

Epithelial cells, which cover the ovary. Most ovarian cancers start in this epithelial covering.

Types of Ovarian Tumors

Many types of tumors can start growing in the ovaries. Some are benign (non-cancerous) and never spread beyond the ovary. Women with these types of tumors can be treated successfully by removing one ovary or the part of the ovary that contains the tumor. Other types of ovarian tumors are malignant (cancerous) and can spread to other parts of the body. Their treatment is more complex and is discussed later in this document.

In general, ovarian tumors are named according to the kind of cells the tumor started from and whether the tumor is benign or cancerous. There are 3 main types of ovarian tumors:

• Germ cell tumors start from the cells that produce the ova (eggs).
• Stromal tumors start from connective tissue cells that hold the ovary together and produce the female hormones estrogen and progesterone.
• Epithelial tumors start from the cells that cover the outer surface of the ovary.

Epithelial Ovarian Tumors

Benign epithelial ovarian tumors: Most epithelial ovarian tumors are benign, do not spread, and usually do not lead to serious illness. There are several types of benign epithelial tumors including serous adenomas, mucinous adenomas, and Brenner tumors.

Tumors of low malignant potential: When looked at under the microscope, some ovarian epithelial tumors do not clearly appear to be cancerous. These are called tumors of low malignant potential (LMP tumors). They are also known as borderline epithelial ovarian cancer. These differ from typical ovarian cancers in that they do not grow into the supporting tissue of the ovary (called the ovarian stroma). Likewise, if they spread outside the ovary, for example, into the abdominal cavity, they do not usually grow into the lining of the abdomen.

These cancers affect women at a younger age than the typical ovarian cancers. LMP tumors grow slowly and are also a less life-threatening disease than most ovarian cancers. Although they can be fatal, this is not common.

Epithelial ovarian cancers: Cancerous epithelial tumors are called carcinomas. About 85% to 90% of ovarian cancers are epithelial ovarian carcinomas. Epithelial ovarian carcinoma cells have several features that can be seen under the microscope. These features are used to classify epithelial ovarian carcinomas into serous, mucinous, endometrioid, and clear cell types. The serous type is by far the most common.

Undifferentiated epithelial ovarian carcinomas don't look like any of these 4 subtypes, and they also tend to grow and spread more quickly. Epithelial ovarian carcinomas are classified by cell type and are also given a grade and a stage.

The grade is on a scale of 1, 2, or 3. Grade 1 epithelial ovarian carcinomas look more like normal tissue and tend to have a better prognosis (outlook). Grade 3 epithelial ovarian carcinomas look less like normal tissue and usually have a worse outlook.

The tumor stage describes how far the tumor has spread from where it started in the ovary. Staging is explained in detail in a later section.

Primary Peritoneal Carcinoma

Primary peritoneal carcinoma is a cancer closely related to epithelial ovarian cancer. It is also sometimes called also called extra-ovarian (meaning outside the ovary) primary peritoneal carcinoma (EOPPC) or serous surface papillary carcinoma. It develops in cells from the peritoneum, which is the membrane that lines the walls and organs of the pelvis and abdomen. These cells are very similar to epithelial cells on the surface of the ovaries. Because EOPPC tends to spread along the surfaces of the pelvis and abdomen, it is often difficult to tell exactly where the cancer first started. Under a microscope, EOPPC looks just like epithelial ovarian cancer. Women who have had their ovaries removed can still develop this type of cancer.

Symptoms of EOPPC are similar to those of ovarian cancer, including abdominal pain or bloating, nausea, vomiting, indigestion, and a change in bowel habits. Also, like ovarian cancer, EOPPC may cause an elevation in the amount of CA-125 in the blood. This is a tumor marker for ovarian cancer (discussed later in this document).

Treatment for women with EOPPC usually includes surgery to remove as much of the cancer as possible, followed by chemotherapy like that given for ovarian cancer. Its outlook is similar to widespread ovarian cancer.

Germ Cell Tumors

About 5% of ovarian cancers are germ cell tumors. Germ cells are the cells that usually form the ova or eggs. There are several subtypes of germ cell tumors. Most germ cell tumors are benign, although some are cancerous and may be life threatening. The most common germ cell tumors are teratoma, dysgerminoma, endodermal sinus tumor, and choriocarcinoma.

Teratoma: This germ cell tumor has a benign form called mature teratoma and a cancerous form called immature teratoma. The mature teratoma is by far the most common ovarian germ cell tumor and usually affects women of reproductive age (teens through forties). It is often called a dermoid cyst because its lining resembles skin. These tumors or cysts also contain a variety of other benign tissues that may resemble adult respiratory passages, bone, nervous tissue, teeth, and other tissues. The patient is cured by surgically removing the cyst.

Immature teratomas occur in girls and young women, usually younger than 18. These are rare cancers that resemble embryonic or fetal tissues such as connective tissue, respiratory passages, and brain. Tumors that are not very immature (grade 1 immature teratoma) and have not spread beyond the ovary are cured by surgical removal of the ovary. When they have spread beyond the ovary and/or much of the tumor has a very immature appearance (grade 2 or 3 immature teratomas), chemotherapy is recommended in addition to surgical removal of the ovary.

Dysgerminoma: This is the most common ovarian cancer of germ cells. However, it is a rare cancer. It usually affects women in their teens and twenties. Although dysgerminomas are considered malignant (cancerous), most do not grow or spread very rapidly. When they are limited to the ovary, more than 75% of patients are cured surgically removing the ovary, without any further treatment. Even when the tumor has spread further (or if it recurs, or comes back) surgery and/or chemotherapy is effective in controlling or curing the disease in about 90% of patients.

Endodermal sinus tumor (yolk sac tumor) and choriocarcinoma: These very rare tumors typically affect girls and young women. They tend to grow and spread rapidly but are usually very sensitive to chemotherapy. Choriocarcinomas more commonly start in the placenta (during pregnancy) rather than in the ovary. Placental choriocarcinomas usually respond even more to chemotherapy than ovarian choriocarcinomas.

Stromal Tumors

More than half of stromal tumors are found in women over age 50, but some occur in young girls. Some, but not all, of these tumors produce female hormones or, less often, male hormones. They can cause vaginal bleeding to start again after menopause, or can cause menstrual periods and breast development in young girls. If male hormones are produced, the tumors can disrupt normal periods and cause facial and body hair to grow. Types of malignant (cancerous) stromal tumors include granulosa cell tumors, granulosa-theca tumors, and Sertoli-Leydig cell tumors, which are usually considered low-grade cancers. Thecomas and fibromas are benign stromal tumors.

Ovarian Cysts

An ovarian cyst is a collection of fluid inside an ovary. Many cysts are completely normal. These are called functional cysts and occur as a normal part of ovulation. The fluid will usually be absorbed and over a few months, the cyst will disappear without any treatment. If you develop a cyst, your doctor may want to check it again after a period of time to see if it has gotten smaller. If, however, the mass is large, occurs in childhood or after menopause, or does not go away, your doctor will usually recommend that you have more tests, since a small number of these cysts may be cancer. Benign cysts are treated by observation (follow-up with physical exams and imaging tests), medications, or surgical removal.

Fallopian Tube Cancer

This is an extremely rare cancer. It begins in the fallopian tube, The symptoms are similar to those in women with ovarian cancer, except that there may be more pelvic pain. Treatment and outlook is similar to that for ovarian cancer. There are no reliable statistics for this cancer because it is so rare.

from cancer.org
http://our-medical-center.blogspot.com/2007/12/ovarian-cancer.html