Gynecologic Cancers

Ovarian Cancer

Background

Ovarian cancer is categorized by the type of cell where it originated. Epithelial ovarian cancer is the most common type of ovarian cancer. It grows on the outer surface of the ovary and accounts for about 90 percent of all ovarian cancers.

Other rare types of ovarian cancer include germ-cell tumors and stromal tumors. Germ cell ovarian cancer originates in the egg-producing cells within the ovaries. Stromal ovarian cancer arises from the supportive tissue around the ovaries. Early detection is important but only about 20 percent of ovarian cancers are found before the tumor has spread beyond the ovaries. Women diagnosed in the earliest stages have a five-year survival rate of approximately 93 percent, according to the American Cancer Society (ACS).

Symptoms

Ovarian cancer symptoms are non-specific and can overlap with many other benign conditions, such as irritable bowel syndrome. For this reason, ovarian cancer can be hard to diagnose.

Symptoms of ovarian cancer can include:

  • Abdominal bloating, distension or sensation of fullness
  • Pelvic discomfort or pain
  • Change in bowel habits with constipation and/or diarrhea
  • Change in urinary frequency and/or urgency
  • Low back pain
  • Pain during sexual intercourse
  • Change in menstruation
  • Fatigue

Risk Factors

Factors associated with an increased risk of developing ovarian cancer include:

  • Age. The probability of getting cancer increases with age. Ovarian cancer is found more often in post-menopausal women. The majority of women diagnosed with the disease are over 63 years of age.
  • Obesity. Women with a body mass index (BMI) over 30 may be at an increased risk of developing ovarian cancer.
  • History of breast cancer. Women who have had breast cancer may be more likely to also develop ovarian cancer.
  • Family history of cancer. Women with a family history of ovarian cancer, breast cancer, or colorectal cancer may have an increased risk for ovarian cancer. There may be inherited genetic mutations that run in families.
  • Hormone therapy. Women taking estrogen after menopause may be at an increased risk, and the risk may be higher for those who have taken estrogen longer than five years. However, the combination of estrogen and progesterone may pose less of a risk than taking estrogen alone.
  • Infertility and fertility drugs. The risk of ovarian cancer may be higher for women who have trouble conceiving and/or women who use fertility drugs.

Staging

Stage I: Cancer is found in one or both of the ovaries. Stage I is divided into Stage IA, IB, and IC.

    • the outside surface of one or both ovaries; or
    • the capsule (outer covering) of the tumor has ruptured; or
    • cancer cells are found in the fluid of the peritoneal cavity or in washings of the peritoneum.
  • Stage IA: Cancer is found in a single ovary.

    Stage IB: Cancer is found in both ovaries.

    Stage IC: Cancer is found in one or both ovaries and in addition to:

Stage II: Cancer is found in one or both ovaries and has spread into other areas of the pelvis. Stage II is divided into Stages IIA, IIB, and IIC.

    Stage IIA: Cancer has spread to the uterus and/or the fallopian tubes.

    Stage IIB: Cancer has spread to other tissue within the pelvis.

    Stage IIC: Cancer has spread to the uterus and/or fallopian tubes and/or other tissue within the pelvis, and cancer cells are found in the fluid of the peritoneal cavity, or in washings of the peritoneum.

Stage III: Cancer is found in one or both ovaries and has spread to other parts of the abdomen. Stage III is divided into Stages IIIA, IIIB, and IIIC.

    Stage IIIA: The tumor is found in the pelvis only, but cancer cells have spread to the surface of the peritoneum.

    Stage IIIB: Cancer has spread to the peritoneum but is 2 centimeters or smaller in diameter.

    Stage IIIC: Cancer has spread to the peritoneum and is larger than 2 centimeters in diameter and/or has spread to lymph nodes in the abdomen.

    Cancer that has spread to the surface of the liver is also considered Stage III disease.

Stage IV: Cancer is found in one or both ovaries and has spread beyond the abdomen to other parts of the body, such as the lungs, liver, lymph nodes, or bones. Cancer that has spread to tissues in the liver is also considered Stage IV disease.

Treatment

Treatment of ovarian cancer usually involves a combination of surgery and chemotherapy.

Surgery
In general, women with ovarian cancer require an extensive operation that includes removing both ovaries, fallopian tubes, and the uterus as well as nearby lymph nodes and the omentum, where ovarian cancer often spreads. The surgeon will also attempt to remove as much cancer as possible from the abdomen (called surgical debulking), which may involve the removal of part of the intestines.

A surgeon will also take samples of tissue and fluid from the abdomen to examine them for cancer cells. This evaluation is critical in identifying the stage of the disease and determining if the patient needs additional therapy.

If a patient wants to preserve the option to have children and if the tumor is discovered early, the surgeon may be able to remove only the involved ovary and its fallopian tube. But, subsequent chemotherapy may cause infertility. However, in some cases, it is possible to successfully bear children after treatment. Be sure to discuss your desire to have children with your doctor.

Chemotherapy
Additional treatment after surgery usually includes intravenous administration of chemotherapy. For example, chemotherapy for ovarian cancer could include the combination of carboplatin (Paraplatin) and paclitaxel (Taxol).

Other treatment options may also include combining standard intravenous chemotherapy with chemotherapy injected directly into the abdominal cavity through a catheter placed at the time of the initial operation.

Other treatments being explored include new chemotherapy drugs, vaccines, gene therapy and immunotherapy, which boosts the immune system to help combat cancer. The newest option, if standard chemotherapy fails, is a drug called bevacizumab (Avastin). It works by disrupting the blood supply to the tumor with the goal of causing it to shrink.

Radiation
Radiation therapy has less of a role in the treatment of ovarian cancer. However, external beam radiation is sometimes used as a palliative option to help decrease the symptoms of advanced cancer.

References
National Cancer Institute, Mayo Clinic, Cancer Treatment Centers of America.