According to American Cancer Society estimates, ovarian cancer will be diagnosed in nearly 21,990 women and 15,460 will perish from the disease in 2011.1 Ovarian cancer is most common in white women older than 65 years. When the disease is caught in stage I, the 5-year survival rate is 94%. However, most cases are not found until stage III or later, when the 5-year survival rate plummets to 40% or lower.1
Women who carry the breast cancer susceptibility genes BRCA1 or BRCA2 have a lifetime risk of 40% for ovarian cancer; those with Lynch II syndrome have a lower risk.2 Women with a history of premenopausal breast cancer; a strong family history of breast or ovarian cancer who do not carry BRCA1 or BRCA2; and those of Ashkenazi descent are also at higher risk. Nulliparity, infertility, and polycystic ovarian disease also increase the risk of ovarian cancer.
DIAGNOSTIC CRITERIA
Ovarian cancer is known as the "silent disease" because its symptoms are elusive and not well-established. Of late, attention has shifted to whether or not ovarian cancer causes specific symptoms. In one study, Goff and colleagues discovered that women with ovarian cancer had more frequent and severe symptoms compared to women with benign disease and controls.3 They also found that having these symptoms more than 12 times per month for less than a year was nearly 60% specific for early-stage disease and 80% sensitive for late-stage disease.4
THE USE OF BIOMARKERS
Cancer antigen 125 (CA-125), a glycoprotein expressed by ovarian tumors, is the biomarker most closely associated with epithelial ovarian cancer. Although alpha-fetoprotein, beta-human chorionic gonadotropin (beta-hCG), lactate dehydrogenase, and inhibin A or B are used to discover cellular types of ovarian cancer, CA-125 is measured most often in women suspected of having ovarian cancer. CA-125 is the only biomarker approved for use during ovarian cancer screening.
In the 1980s, Bast and colleagues discovered that nearly 80% of patients with diagnosed ovarian cancer had a CA-125 level greater than 35 U/mL.5 However, CA-125 is neither sensitive nor specific for ovarian cancer; false-positive results can occur if patients have endometriosis, diverticulitis, pregnancy, cirrhosis, pelvic inflammatory disease, or leiomyomas. False-positive results may also occur in patients with breast, colon, and pancreatic carcinomas who have a high CA-125 level.
Testing for CA-125 is most effective when used with transvaginal and pelvic ultrasonography during the workup for suspected disease prior to surgery, during chemotherapy, and in the surveillance period following chemotherapy. During the surveillance period, serum CA-125 levels should be monitored for any rise. Studies have shown that even a small rise in the CA-125 level is indicative of recurrence, even if the current levels are within the normal range (less than 35 U/mL).6,7
WHO TO SCREEN
High-risk women with a genetic mutation or strong family history should be screened. Routine transvaginal and pelvic ultrasonography with a CA-125 test may help detect disease early. Exercising, eating a healthy diet, and not smoking lower the risk of disease. Oral contraceptives and prophylactic bilateral oophorectomy may be offered if the benefits outweigh the risks.
The American College of Obstetricians and Gynecologists, the Society for Gynecologic Oncologists, the National Institutes of Health, and the United States Preventive Services Task Force have all recommended against screening the general population. Until more adequate screening tools are identified, health care providers should talk with their patients about any possible symptoms, especially those that are out of the ordinary. Family history should also be discussed. Patients with a family history significant for ovarian cancer should be referred to a genetic counselor and be tested for genetic mutations. JAAPA
Heidi Felix is an assistant professor and clinical coordinator of the PA program at Chatham
University in Pittsburgh, Pennsylvania. The author has indicated no relationships to disclose relating to the content of this article.
Mary L. Hewett, PA-C, MS, department editor
REFERENCES
1. What are the key statistics about ovarian cancer?
American Cancer Society. http://www.cancer.org/Cancer/
OvarianCancer/DetailedGuide/ovarian-cancer-key-statistics. Updated August 11, 2011. Accessed August 19, 2011.
2. Buys SS, Partridge E, Greene MH, et al; PLCO Project Team. Ovarian cancer screening in the Prostate, Lung, Colorectal and Ovarian (PLCO) cancer screening trial: findings from the initial screen of a randomized trial. Am J Obstet Gynecol. 2005;193(5):1630-1639.
3. Goff BA, Mandel LS, Melancon CH, Muntz HG. Frequency of symptoms of ovarian cancer in women presenting to primary care clinics. JAMA. 2004;291(22):2705-2712.
4. Goff BA, Mandel LS, Drescher CW, et al. Development of an ovarian cancer symptom index: possibilities for earlier detection. Cancer. 2007;109(2):221-227.
5. Bast RC Jr, Feeney M, Lazarus H, et al. Reactivity of a monoclonal antibody with human ovarian carcinoma. J Clin Invest. 1981;68(5):1331-1337.
6. Armstrong DK, Bundy B, Wenzel L, et al; Gynecologic Oncology Group. Intraperitoneal cisplatin and paclitaxel in ovarian cancer. N Engl J Med. 2006;354(1):34-43.
7. Wilder JL, Pavlik E, Straughn JM, et al. Clinical implications of a rising serum CA-125 within the normal range in patients with epithelial ovarian cancer: a preliminary investigation. Gynecol Oncol. 2003;89(2):233-235.
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