Cancer of the Ovary

CANCER OF THE OVARY

Ovarian cancer causes more deaths than any other cancer of the female reproductive system. About 75% of cases are detected at a late stage (Duffy, 2001). The ovary is a common site of primary as well as metastatic lesions from other cancers. Most cases affect women ages 50 to 59. The incidence of ovarian cancer is highest in industrialized countries, except for Japan, where its incidence is low.

A woman with ovarian cancer has a threefold to fourfold in-creased risk for breast cancer, and women with breast cancer have an increased risk for ovarian cancer. No definitive causative fac-tors have been determined, but oral contraceptives appear to pro-vide a protective effect. Heredity plays a part, and many physicians advocate pelvic examinations every 6 months for women who have one or two relatives with ovarian cancer. Despite careful ex-amination, ovarian tumors are often difficult to detect because they are usually deep in the pelvis. No early screening mechanism exists at present, although tumor markers are being explored. Transvaginal ultrasound and Ca-125 antigen testing are helpful in those at high risk for this condition. Tumor-associated antigens are helpful in follow-up care after diagnosis and treatment but not in early general screening.

Advances in our knowledge of genetics are changing the ap-proaches to detecting and treating breast and ovarian cancer. Some families have specific genes that predispose them to various cancers. BRCA-1 is a genetic mutation that results in an increased risk for breast and ovarian cancer. BRCA-2 is another genetic mutation that may result in increased risk for both female and male breast cancers and for ovarian cancer (Duffy, 2001). Other mutations are also under study. Testing for susceptibility is in the early stages at centers that have expertise in genetics, testing, and counseling. Testing is indicated when a family history of three or more cases of closely related members includes premenopausal breast cancer or ovarian cancer. One member with cancer is tested, and if the results are positive, other members without can-cer may undergo testing.

Much more needs to be learned about the risks associated with some mutations, the reliability of testing, and the efficacy of follow-up. Confidentiality and insurance risks are ethical issues that need clarification. Because there are no primary methods of preventing breast or ovarian cancer, emotional distress is also a problem. Patients with concerns about their family history should be referred to a cancer genetics center to obtain information and testing, if indicated. Women with inherited types of ovarian can-cer tend to be younger when the diagnosis is made than the aver-age age of 59 years at the time of diagnosis.

Risk factors also include nulliparity and infertility. Older age is a major risk factor because the incidence of this disease peaks in the eighth decade of life. High dietary fat intake, mumps be-fore menarche, use of talc in the perineal area, and family history are suspected to increase risk, while multiparity, oral contracep-tive use, breastfeeding, and anovulatory disorders may be protec-tive. Survival rates depend on the stage of the cancer at diagnosis.

Fifteen percent of all new cases of ovarian tumors have low malignancy potential (LMP tumors). These borderline tumors resemble ovarian cancer but have much more favorable out-comes. Women diagnosed with this type of cancer tend to be younger, in their early 40s. A conservative surgical approach is now used. The affected ovary is removed, but the uterus and the contralateral ovary may remain. Adjuvant therapy may not be warranted for these tumors.

Clinical Manifestations

Symptoms are nonspecific and include increased abdominal girth, pelvic pressure, bloating, indigestion, flatulence, increased waist size, leg pain, and pelvic pain. Symptoms are often vague, and many women ignore the symptoms. Ovarian cancer is often silent, but enlargement of the abdomen from an accumulation of fluid is the most common sign. Any woman with gastrointestinal symptoms and without a known diagnosis must be evaluated with ovarian cancer in mind. Flatulence, fullness after a light meal, and increasing abdominal girth are significant symptoms.

Vague, undiagnosed, persistent gastrointestinal symptoms should alert the nurse to the possibility of an early ovarian malig-nancy. A palpable ovary in a woman who has gone through meno-pause is investigated because ovaries normally become smaller and less palpable after menopause.

Assessment and Diagnostic Findings

Any enlarged ovary must be investigated. Pelvic examination often does not detect early ovarian cancer, and pelvic imaging tech-niques are not always definitive. About 75% of ovarian cancers have metastasized by the time of diagnosis; about 60% have spread beyond the pelvis. Of the many different ovarian cancer cell types, epithelial tumors constitute 90%. Germ cell tumors and stromal tumors make up the other 10%.

Medical Management

SURGICAL MANAGEMENT

Surgical staging, exploration, and reduction of tumor mass are the basics of treatment. Surgical removal is the treatment of choice; the preoperative workup includes a barium enema or colonoscopy, upper gastrointestinal series, chest x-rays, and intravenous urog-raphy. CT scans and immunoscintigraphy, the use of radioactive antibodies, may be used preoperatively to rule out intra-abdominal metastasis. Staging the tumor is important to guide treatment (Chart 47-9). A total abdominal hysterectomy with removal of the fallopian tubes and ovaries and the omentum (bilateral salpingo-oophorectomy and omentectomy) is the standard procedure for early disease.

PHARMACOLOGIC THERAPY

Chemotherapy often follows surgery, usually with cyclo-phosphamide (Cytoxan), doxorubicin (Adriamycin), cisplatin (Platinol-AQ), carboplatin (Paraplatin), or paclitaxel (Taxol). Hexamethylmelamine (Hexalen), ifosfamide (Ifex), bone marrow transplantation, and peripheral blood stem cell support may also be used. Paclitaxel, cisplatin, and carboplatin are most often used because of their excellent clinical benefits and manageable toxic-ity. Leukopenia, neurotoxicity, and fever may occur.

Paclitaxel, an agent derived from the Pacific yew tree, works by causing microtubules within the cells to gather and prevents the breakdown of these threadlike structures. In general, cells can-not function when they are clogged with microtubules and can-not divide. Because this medication often causes leukopenia, the patient may need to take granulocyte colony-stimulating factor as well.

Paclitaxel is contraindicated in patients with hypersensitivity to medications formulated in polyoxyethylated castor oil and in patients with baseline neutropenia. Because of possible adverse cardiac effects, paclitaxel is not used in patients with cardiac dis-orders. Hypotension, dyspnea, angioedema, and urticaria indi-cate severe reactions that usually occur soon after the first and second doses are administered. The nurse must be prepared to as-sist in treating anaphylaxis. The patient should be prepared for inevitable hair loss.

Cisplatin is used frequently in chemotherapeutic treatment of ovarian cancer, both alone and in combination with other agents, and in intraperitoneal applications. Patients may require bone marrow transplantation or stem cell transplantation to treat ovarian cancer. Intraperitoneal chemotherapy with cisplatin may provide a prom-ising mode of treatment.

Carboplatin may be used in the initial treatment of advanced ovarian cancer in combination with other chemotherapeutic agents. It may also be used in patients with recurrence of ovarian cancer after other chemotherapy, including cisplatin. It must be used with caution in patients with renal impairment.

Other medications include topotecan (Hycamtin), irinotecan (Camptosar), gemcitabine (Gemzar), vinorelbine (Navelbine), li-posomal doxorubicin (Doxil), and docetaxel (Taxotere). Differ-ent combinations, different regimens, different routes, and use of growth factors are being investigated.

Liposomal therapy, delivery of chemotherapy in a liposome,allows the highest possible dose of chemotherapy to the tumor tar-get with a reduction in adverse effects. Liposomes are used as drug carriers because they are nontoxic, biodegradable, easily available, and relatively inexpensive. This encapsulated chemotherapy allows increased duration of action and better targeting. The encapsula-tion of doxorubicin lessens the incidence of nausea, vomiting, and alopecia. The patient must be monitored for bone marrow sup-pression. Gastrointestinal and cardiac effects may also occur. These medications are administered by oncology nurses as a slow intra-venous infusion over 60 to 90 minutes.

Genetic engineering and identification of cancer genes may make gene therapy a future possibility. Gene therapy is under in-vestigation. Radiation may be helpful and is more useful in some types of ovarian cancer than others.

After adjunct therapies are completed, a second-look lapa-roscopy or a laparotomy may be performed in some clinical cen-ters to evaluate the treatment results and to obtain multiple tissue samples for biopsy. Occasionally, catheters are left in place if radio-active agents are to be used postoperatively. Chemotherapy is the most common form of treatment in advanced disease.

Nursing Management

Nursing measures include those related to the patient’s treatment plan, be it surgery, chemotherapy, radiation, or palliation. Emo-tional support, comfort measures, and information, plus atten-tiveness and caring, are meaningful aids to the patient and her family.

Nursing interventions after pelvic surgery to remove the tumor are similar to those after other abdominal surgeries. If ovarian cancer occurs in a young woman and the tumor is uni-lateral, it is removed. Childbearing, if desired, is encouraged in the near future. After childbirth, surgical re-exploration may be performed and the remaining ovary may be removed. If both ovaries are involved, surgery is performed and chemotherapy follows.

Patients with advanced ovarian cancer may develop ascites and pleural effusion. Nursing care may include administering intra-venous therapy to alleviate fluid and electrolyte imbalances, initi-ating parenteral nutrition to provide adequate nutrition, providing postoperative care after intestinal bypass to alleviate an obstruction, and providing pain relief and managing drainage tubes. These con-ditions are complex and often require assistance and support from an oncology nurse specialist. Comfort measures for women with ascites may include providing small frequent meals, decreasing fluid intake, administering diuretic agents, and providing rest. Patients with pleural effusion may experience shortness of breath, hypoxia, pleuritic chest pain, and cough. Thoracentesis is usually performed.