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According to recent reports published by the American Cancer Society, in 2005 an estimated 22,220 new cases of ovarian cancer will be diagnosed in the United States, and an estimated 16,210 deaths from ovarian cancer will occur.1 Ovarian cancer, one of several diseases in which malignant cells arise from the ovary, is the second most common form of gynecological cancer diagnosed in women in the United States. While ovarian cancer accounts for approximately 3 percent of all cancer among women it has been shown to cause more deaths than any other cancer of the female reproductive system.2
The 5-year relative survival rate for ovarian cancer of all stages combined is 44 percent. However, reports from the national Cancer Institute indicates that, if ovarian cancer is diagnosed when the disease is localized, the 5-year survival rate is 94 percent.3
Pathology and Epidemiology
The ovaries comprise three distinct cell types: epithelial cells, germ cells, and stromal cells. Each of these cell types can give rise to ovarian cancer.
About 80 percent of ovarian cancers are epithelial ovarian carcinomas. Epithelial ovarian carcinomas originate in the epithelial tissue of the ovary. Epithelial neoplasms are classified as serous, mucinous, endometrioid, clear cell, or transitional cell ovarian cancer based on the type of epithelial differentiation that is present in the tumor. The risk of epithelial ovarian cancer increases with age, especially after the age of 50. Epithelial ovarian cancer accounts for approximately 10-15 percent of all ovarian cancers and originates in the egg-producing cells found within the ovary.
Germ cell ovarian cancer can occur in women of any age, but approximately 80 percent are diagnosed in women under the age of 30.
Sex cord stromal ovarian cancers, which account for approximately 5-10 percent of all ovarian cancers, are composed of various cell types derived from gonadal stroma and sex cords. Sex cord stromal ovarian cancers account for most of the hormonally active ovarian tumors. Sex cord ovarian cancer is relatively rare and generally less aggressive than other ovarian cancers.
Risk Factors
While scientists remain uncertain as to exactly what causes the development of germ cell ovarian cancer and stromal ovarian cancer, research has lead to the identification of several factors that increase a woman's risk of developing epithelial ovarian cancer. These factors include age; race; ethnicity; reproductive history; hormonal history; personal history of breast cancer; and family history of ovarian, breast or colon cancer.
| Table 1: Ovarian Cancer Risk Factors 1,3 Â |
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Age |
Most ovarian cancers develop after menopause. |
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Personal History |
Women who have had breast cancer also have a higher risk of developing ovarian cancer. |
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Family History |
Women who have a first-degree relative with ovarian, endometrial, breast or colon cancer are at greater risk of developing ovarian cancer. |
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Reproductive History |
The greater the number of pregnancies, the lower the risk for developing ovarian cancer. |
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Hormonal Therapy |
The prolonged use of estrogen alone as a post-menopausal hormone therapy increases the risk of developing ovarian cancer. The risk of ovarian cancer in women who used ERT for longer than 10 years is double that of women who never used it. |
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Race |
Ovarian cancer occurs 50 percent more frequently in white women than black women. |
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Ethnicity |
The highest incidence rate of ovarian cancer occurs in European women of Jewish ancestry. |
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Genetic Mutations |
Ovarian cancer risk is increased in women with mutations in BRACA1 or BRCA2 genes or a genetic mutation leading to inherited colorectal cancer. |
Early DetectionÂ
There are no screening tests accurate enough to be used for routine screening of women without symptoms for detecting early stage ovarian cancer. Nonetheless, it is recommended that all women who become sexually active or who are over the age of 18 should have regular pelvic and rectal examinations and Pap smears.
| Unexplained Fatigue: One Patient's Story |
"In retrospect, I feel betrayed by the healthcare system. I was stunned at the cavalier attitude my providers had towards my complaints. Over the past 2 years I had been in to see my doctors on five separate occasions with a primary complaint of unexplained fatigued. I was falling asleep behind the wheel driving from my work site to my home. On several occasions, I had to pull off the road and sleep or stop and get a motel room because I just could not drive the distance safely."
"The fatigue progressed. I began experiencing difficulty driving shorter distances. The doctors did a few routine screening tests -- WBC, RBC, platelets, thyroid, and liver function tests. But that was it! Then they threw their hands up in the air and walk away and said, 'We don't know'. So they quit looking."
"I even fought with the gynecologic physician the year before my diagnosis pushing for a hysterectomy. I was sure the problem was female reproductive related. She refused to do any scans, work ups, nothing beyond the routine exam and Pap smear."
I had to fight hard for a thorough work up. It was not until I told them I was going to sleep on the floor in the clinic, scream, yell, and do whatever it took to get someone to do a workup on me, did they take my seem to take my concerns seriously."
"After 2 years of fighting, finally I received a thorough examination and aggressive testing. Not long after this incident I was diagnosed with Stage III ovarian cancer." |
Most early-stage ovarian tumors are difficult to feel. However, in some instances, an ovarian mass can occasionally be detected during the pelvic and rectal examination. The Pap test has been shown to be a very effective test for detecting cervical cancer early. However, the Pap test is not an effective test for detecting early stage ovarian cancer. A Pap test will detect ovarian cancer in only 10 percent of women with the disease.
Among many women with ovarian cancer, pelvic, rectal and physical examinations often reveal the presence of a firm, nodular, fixed adnexal, abdominal or pelvic mass; ascites; pleural effusion; inguinal lymphadenopathy and/or supraclavicular lymphadenopathy. Yet, ovarian cancer ordinarily produces no distinctive or intense symptoms. When symptoms of ovarian cancer do appear, they are often vague and mimic other more common less serious ailments. As a result, ovarian cancer is often advanced at the time of diagnosis.
It is essential for healthcare providers to consider ovarian cancer as a possible diagnosis when caring for adult women, especially those 40 years of age and older, with persistent, nonspecific complaints of abdominal/pelvic enlargement, discomfort or pressure; back or leg pain; gastrointestinal symptoms (e.g., decreased appetite, early satiety, gas, long-term stomach pain, indigestion); urinary symptoms (e.g., urgency, burning or spasms); or unexplained weight loss or gain on examination that cannot be explained by any other cause.Â
Other vague, but sometimes lingering, symptoms of ovarian cancer include:
- Changes in bowel function or urinary frequencyÂ
- Gastrointestinal symptoms (e.g., nausea, gas, long-term stomach pain, indigestion, loss of appetite)Â
- Malnourished or wasted appearance
- Unusual vaginal bleeding
- Shortness of breath
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