Ovarian Cancer : Diagnostic Procedures, Treatment Options

by Food and Drug Administration (FDA)

(Page 3 of 5)

Diagnostic Procedures

If a woman or her doctor suspects ovarian cancer, diagnosis begins with a medical history of the patient, review of her symptoms, and complete physical examination, including a pelvic exam, in which the physician feels the vagina, ovaries, fallopian tubes, bladder, and rectum to check for any growths. A Pap test may also be done because, even though it cannot reliably detect ovarian cancer, it may detect cancer cells that have migrated to the uterine cervix from the ovaries.

Blood and urine tests may also be done, as well other procedures, depending on the woman's symptoms and results of her physical exam. These procedures include:

Abdominal or transvaginal ultrasound — helps distinguish fluid-filled cysts from a solid tumor

CAT scan — produces x-ray images of cross-sections of body tissues

Lower GI series (barium enema) — visualizes the bowel on x-ray to detect abnormal areas that may be caused by ovarian cancer

Intravenous pyelogram (IVP) — produces x-ray pictures of the kidneys, bladder and ureters (tubes carrying urine from the kidneys to the bladder). Often, ovarian cysts or tumors can cause pressure on these organs, which may show up on an IVP.

The only sure way to diagnose ovarian cancer, however, is through microscopic examination by a pathologist of abnormal-looking fluid or tissue. While fluid can sometimes be obtained by needle aspiration or other techniques, more commonly a laparatomy or laparoscopy is done. Laparotomy is an exploratory operation in which the surgeon examines the abdomen thoroughly and removes fluid or tissue for examination. In laparascopy, a flexible, lighted tube is passed through a small incision in the abdomen, allowing the surgeon to examine the area and extract tissue for a biopsy.

If cancer is suspected, the surgeon usually removes the entire affected ovary to avoid cutting through the outer layer, which might cause the tumor to spread.

The tissue is sent to the pathologist for immediate evaluation, and if cancer is confirmed, the surgeon nearly always removes the second ovary, the uterus, and the fallopian tubes. Samples are taken of nearby lymph nodes, the diaphragm, the omentum (a fold of membranous lining in the abdominal cavity), and fluid from the abdomen to see whether the cancer has spread. If no fluid is found, several "washings" are taken: A saline solution is put into the abdomen and then removed to be examined for cancer cells. If there are suspicious lesions, tissue samples are also taken from the liver, small intestine, and large intestine.

Early Treatment Crucial

Trusting her instincts may have saved Jessica Marsh's life. Due in part to her own vigilance and persistence, Marsh (not her real name), a secretary in Rockville, Md., was diagnosed before her cancer had spread beyond the ovary, affording her a brighter prognosis.

For three months in the fall of 1985, Marsh, then 36 years old, had noticed pains in her right side around the time of her menstrual periods. Although the pains were brief and not severe, she decided to have her doctor check it out. A week or so before her appointment, however, a very sharp pain prompted her to call the doctor again. Her gynecologist was out of town, but the doctor on call had her come in.

"He told me that my stomach was distended, gave me a pelvic exam, and then congratulated me, telling me I was three months pregnant," Marsh recalls. "I told him I wasn't pregnant, that I already had two children and knew what it was like to be pregnant, and this was not a pregnancy."

At Marsh's insistence, the physician arranged for her to have a pelvic sonogram that day at a local hospital.

"I had the sonogram and the next thing I knew, the doctor who had examined me at the office came in, repeated the sonogram, and told me there was a mass and he wanted to do some more tests. The next morning, I had surgery to remove my ovaries, uterus, and fallopian tubes."

Although Marsh's experience may not be typical, it illustrates again the difficulty in correctly diagnosing the disease early. Yet, early detection and treatment can mean the difference between life and death.

Treatment Options

Ovarian cancer is always treated surgically, removing as much tumor as is feasible. Chemotherapy (drug treatment) or radiation therapy, or both, may also be given, depending on the extent of disease. Ovarian tumors usually grow outward, with an irregular, cauliflower-like shape. When the cancer spreads, parts of the tumor break off and attach to nearby organs. Cells may then spread to lymph nodes and distant organs.

Cancer limited to the ovaries may be successfully treated with surgery alone, removing the ovaries, fallopian tubes, omentum (a fold of tissue attached to organs in the abdominal cavity), and uterus. Some patients may also receive chemotherapy or radiation therapy to kill any cancer cells remaining after surgery.

Disease that has spread beyond the ovaries almost always requires chemotherapy or radiation therapy in addition to surgery. Radiation therapy may be given by placing a radioactive solution into the pelvis and abdomen through a thin tube, coating the organs and total abdominal contents. Less commonly, external radiation using high-energy x-rays directed to the pelvis and abdomen may be prescribed.

The type of drugs used in chemotherapy depends not only on the extent of disease, but also on the type of cancer. About 85 to 90 percent of ovarian cancers arise from epithelial cells, which form the outer layer of the ovary. The rest derive from other cell types that make up the organ.

FDA has approved several drugs to treat ovarian cancer. Two of the most commonly used are Platinol (cisplatin) and Taxol (paclitaxel). Taxol was approved in April 1998 as a first-line treatment for advanced ovarian cancer. It has been used since December 1992 to treat advanced ovarian cancer that has not responded to other therapies or has progressed after treatment (see "Taxol's Long History"), and is being evaluated for first-line treatment. National Cancer Institute and FDA scientists cooperated in studies to evaluate the safety and effectiveness of Taxol. FDA's research role in drug development is a fairly new concept, designed to help speed the approval process for drugs for life-threatening diseases.

"It's a commitment by the agency to do more than just wait for packages of data to come in [from the drug's sponsor] and review them for approval," says Jerry M. Collins, Ph.D., director of the division of clinical pharmacology research in the Center for Drug Evaluation and Research. "We can't do this for every new drug in every therapeutic area," he says, "but for AIDS and cancer, we have done similar research before."

Since Taxol is given in combination with several other drugs, there was major concern about the potential for serious drug interaction. However, according to Collins, this research demonstrated that "paclitaxel actually had a lower risk of metabolic interactions than most other drugs."

Other chemotherapeutic agents used to treat ovarian cancer include Cytoxan and Neosar (cyclophosphamide), Paraplatin and Adriamycin (doxorubicin), and Hexalen (altretamine). A recent addition is Hycamtin (topotecon, approved in 1996 to treat ovarian cancer that recurs after other chemotherapeutic agents have failed. Hycamtin is the first of a new class of drugs called topoisomerase I inhibitors. They kill cancer cells by inhibiting an enzyme essential to the replication of human DNA.

About the Author

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