What are ovarian germ cell tumors?

Germ cell tumors make up about 2 to 3 percent of all ovarian cancers, according to the American Cancer Society (ACS). Germ cells are the egg cells located in the ovaries in women and the sperm cells located in the testes in men. Growths that develop in egg cells are called ovarian germ cell tumors. These tumors may be benign (noncancerous) or malignant (cancerous).

Malignant ovarian germ cell tumors most often occur in teenage girls and younger women. Typically, only one ovary is affected. Ovaries, where eggs and hormones are made, usually resemble an almond in size and shape. When an ovarian germ cell tumor is in an advanced stage, the mass may be felt on the ovary.

Types of malignant ovarian germ cell tumors

There are several types of malignant ovarian germ cell tumors, including those below.

• Dysgerminoma: This slow-growing cancer begins in female germ cells and causes dysregulation of the hormone beta-human chorionic gonadotropin (beta-hCG), which the body produces at higher levels when pregnant. Dysgerminoma is the most common type of ovarian germ cell tumor.
• Endodermal sinus tissue: This type of cancer is rare and begins in the germ cells of the ovary (although it may also occur in the chest, abdomen or brain). Also called yolk sac tumors, they may be aggressive, growing quickly and spreading to other areas of the body.
• Immature teratoma: An uncommon type of ovarian germ cell tumor, immature teratomas typically consist of noncancerous tissue with some cancerous areas.
• Choriocarcinoma: This fast-growing cancer spreads through the blood, most often affecting the lungs. These tumors are highly aggressive and rare. Most choriocarcinomas form in the uterus.
• Embryonal carcinoma: Another rare type of ovarian germ cell cancer, this typically occurs in adolescence.

Symptoms of ovarian germ cell tumors

Ovarian germ cell tumors don’t typically cause symptoms at first, which makes them harder to detect early. As the cancer progresses, noticeable symptoms may include:

• Abdominal mass
• Abdominal swelling and pain
• Tumor markers in the blood (certain substances that indicate cancer)

Causes and risk factors of ovarian germ cell tumors

The exact cause of ovarian germ cell tumors is unknown, but certain inherited birth defects or genetic conditions (chromosomal abnormalities or gene mutations) may increase the risk of developing the disease. Most often, this type of tumor is seen in teenage girls and younger women, or in women older than 60.

How ovarian germ cell tumors are diagnosed

To diagnose ovarian germ cell tumors, the following tests to examine the pelvic area, blood and ovarian tissue may be performed.

• Physical exam: A doctor may conduct a physical exam to look for any palpable abdominal masses.
• Pelvic exam: Using gloved hands, a doctor may examine the vagina, cervix, fallopian tubes, ovaries and rectum, checking for abnormalities. A Pap test to check the cervix for signs of disease may also be done.
• Laparotomy or laparoscopy: During this surgical procedure, one or more incisions are made in the abdomen to check organs for signs of cancer. Tissue samples may be removed to be examined under a microscope.
• Computed tomography (CT) scan: This procedure involves a series of highly detailed pictures of internal organs.
• Serum tumor marker test: This blood test checks for elevated levels of substances that are linked to specific cancer types. Elevated levels of hCG (human chorionic gonadotropin), LDH (lactate dehydrogenase) or AFP (alpha-fetoprotein) are associated with ovarian germ cell tumors.

Once an ovarian germ cell tumor has been diagnosed, further testing may be done to find out whether the cancer has spread to other parts of the body. These include:

• Positron emission tomography (PET) scan
• Magnetic resonance imaging (MRI)
• Transvaginal ultrasound exam

Staging

Before recommending a treatment plan, doctors need to determine the stage of the patient’s cancer.

Stage 1: Cancer may be either in the ovaries or fallopian tubes.

• In stage 1A, cancer is in a single ovary or fallopian tube.
• In stage 1B, it’s inside both ovaries or fallopian tubes.
• In stage 1C, cancer is in one or both ovaries and/or fallopian tubes in addition to one of the following: the outer covering (capsule) of the ovary has torn open; or cancerous cells are found in either the fluid of the abdomen and pelvis (peritoneal cavity) or the tissue lining the abdomen (peritoneum).

Stage 2: The disease has spread from the ovaries and/or fallopian tubes to other organs in the pelvis.

• In stage 2A, the cancer has metastasized to the uterus.
• In stage 2B, the cancer has spread to the peritoneal cavity.

Stage 3: Cancer has spread to other organs in the pelvis or in the abdomen and/or lymph nodes.

• In stage 3A, cancer has either traveled to lymph nodes in areas outside or behind the abdominal cavity, or the disease has made its way to nearby organs in the pelvis.
• In stage 3B, cancer has metastasized to an area of the peritoneum beyond the pelvis, and takes up a surface area smaller than 2 cm. It may or may not be found in lymph nodes in the abdominal cavity.
• In stage 3C, the cancerous area is greater than 2 cm. Additionally, it may have spread to lymph nodes behind the peritoneum, but it has not reached the spleen or the insides of the liver and has not spread to distant sites.

Stage 4: Cancer has spread outside of the abdomen into other areas of the body.

• In stage 4A, cancer cells are identified in the fluid that surrounds the lungs.
• In stage 4B, the cancer has metastasized to other organs, tissues and lymph nodes outside of the abdomen, including the groin.

Treatment

The type of treatment recommended depends on the location and stage of the cancer. Below are standard treatments currently used.

Surgery: Surgery to remove the cancer is the most common treatment for ovarian germ cell tumors. One ovary and fallopian tube may be removed in a procedure called unilateral salpingo-oophorectomy. Sometimes, further biopsies and lymph node sampling are necessary. More invasive cases may require a total hysterectomy, to remove the entire uterus and cervix. A radical hysterectomy involves the removal of both ovaries and fallopian tubes and nearby tissues, in addition to the uterus and cervix. In a procedure called tumor debulking, a surgeon removes as much of the cancerous tumor as possible.

Observation: With this approach, the care team may watch and wait, closely observing any changes.

Radiation: High-energy X-rays or other forms of radiation are used to kill cancer cells or prevent them from growing.

Chemotherapy: Chemotherapy works by inhibiting the growth of cancer cells. For ovarian germ cell tumors, treatment may include a combination of chemotherapy drugs.

Ovarian germ cell tumor survival rates

The five-year survival rate for cancer that hasn’t spread outside the ovaries (localized stage) is 98 percent, according to the ACS. The survival rate is 94 percent for regional cancer that has spread to nearby organs, tissues or lymph nodes (regional stage) and 73 percent for cancer that has metastasized to distant parts of the body such as the liver and lungs (distant stage).