Ovarian Cancer Diagnosis

  • Diagnosis

    Ovarian cancer involves abnormal cell growth that begins in the ovaries Figure 01. The ovaries are two small, almond-shaped organs located on each side of the uterus. The ovaries produce female hormones, and also contain eggs, one of which is released every month during ovulation throughout a woman’s reproductive years.

    Click to enlarge: Female reproductive system anatomy

    Figure 01. Female reproductive system anatomy

    Ovarian cancer is relatively uncommonOvarian cancer accounts for only 4% of all cancers in women. The disease occurs most often in postmenopausal women, with the average age of diagnosis around 60 years.

    Because symptoms of ovarian cancer tend to be vague and similar to symptoms of many less serious illnesses, most cases are diagnosed after the cancer has spread beyond the ovaries. About three-quarters of women with ovarian cancer are diagnosed with advanced-stage disease. Typical symptoms of ovarian cancer, such as stomach upset and bloating, are indications of disease that may have already spread. Unfortunately, the symptoms are often mistaken for a gastrointestinal problem, which can further delay the correct diagnosis.

    Ovarian cancer is classified into three major types—epithelial, germ cell, and sex cord-stromal—depending on the part of the ovary in which the disease started.

    • Epithelial tumors develop from cells that make up the surface covering the ovaries. It is the most common type of ovarian cancer, comprising 90% of cases.
    • Germ cell tumors come from the type of cells that form eggs during development. Only about 5% of cases of ovarian cancer are germ cell tumors. They most commonly occur in young women and girls, typically before the age of 30.
    • Sex cord-stromal tumors arise from cells that secrete hormones and form connections within the ovary. They make up less than 5% of cases.

    Inheritance is thought to play a role in ovarian cancer. Genetic mutations known as BRCA 1 and BRCA 2 that increase a woman’s risk for ovarian and breast cancer run in some families, but only account for no more than 5% to 10% of cases. There is also a genetic condition, hereditary nonpolyposis colorectal cancer, that increases the risk of colon cancer, and other types of cancer, including ovarian cancer, in affected families.

    The length of time that women have menstrual cycles can influence the risk for getting ovarian cancer. A woman’s risk of developing ovarian cancer is also related to the number of times a woman ovulates throughout her life. Women who are at higher risk include those who:

    • started their menstrual periods at an early age
    • had late menopause; or
    • never interrupted their ovulation with birth control pills or pregnancies.

    There may be no symptoms in the early stages of the disease. When symptoms do appear, they are often vague, leading many women to ignore them and doctors to suspect other problems. The ovaries lie deep within the pelvis, and symptoms are usually not noticed until the cancer has spread to the abdomen. Typical symptoms may easily be mistaken for a gastrointestinal or bladder problem. Symptoms include:

    • pelvic or abdominal pain or discomfort
    • gas, nausea, and indigestion
    • frequency or urgency in urination
    • changes in bowel habits
    • unexplained weight gain or loss
    • swelling of the pelvis or abdomen
    • painful intercourse
    • abnormal vaginal bleeding
    • back pain
    • fatigue

    Ovarian cancer of the sex cord-stromal type may actually secrete female or male sex hormones. Therefore, this type of ovarian cancer can cause symptoms of hormonal imbalance, such as a change in menstrual periods, bleeding after menopause, the appearance of facial hair, or a change in the voice.

    Many risk factors have been identified for ovarian cancer. However, most cases develop in women who are not in a high-risk group.

    The risk for ovarian cancer increases as a woman gets older. An estimated one woman in 70 will develop ovarian cancer during her lifetime. The majority of ovarian cancers of the epithelial type are diagnosed in postmenopausal women.

    A personal or family history of ovarian cancer, as well as certain other cancers, is an important risk factor. A family history on either the mother’s or father’s side, or both, of the following cancers can carry an increased risk for ovarian cancer:

    • ovarian
    • breast
    • endometrial
    • colon or rectal
    • pancreatic

    Risk is increased if one of these cancers is present in a close relative, such as a parent, sibling, or child, or in more than one distant relative, such as a grandparent or aunt.

    Women with a strong family history may wish to be tested for mutations to BRCA 1 and BRCA 2 genes, which indicate a high lifetime risk of ovarian and breast cancer. Jews of Eastern European descent are at a much higher risk of having these mutations than other groups, at a rate of 2 in 100 rather than the 2 in 1,000 in the general population. Women with the mutation are also more likely to develop ovarian cancer before menopause. In addition, if a women has had breast cancer, then her risk of ovarian cancer may be increased.

    The risk for ovarian cancer increases when women do not have children or do not use birth control pills. In fact, using birth control pill for 5 years or longer can cut the risk of ovarian cancer in half.

    Using hormone replacement therapy with estrogen and progesterone to treat menopause has been shown to be safe in most studies. In one study, however, a slightly increased risk was found in women who took HRT for longer than 15 years. Therefore, this issue requires further study.

    Dietary factors are suspected of being involved in many different types of cancer; however, specific associations are still unclear. Because women who live in industrialized countries (with the exception of Japan) have the highest rates of ovarian cancer, a diet high in animal fat is suspected to be a risk factor for the disease. However, the role of fat in the diet is complicated, not only because there are many different kinds of fats, but also because fats are high in calories. Therefore, it is not known whether fats themselves, or simply a high-calorie diet, is responsible for the increased cancer risk.

    The NCI American Cancer Society Guidelines on Diet and Nutrition recommends adhering to the following guidelines to the reduce the risk for all cancers:

    • Maintain a desirable body weight
    • Eat a variety of foods daily, including fruits and vegetables
    • Eat more high-fiber foods such as whole grain cereals, legumes, vegetables, and fruits
    • Reduce the amount of dietary fat you consume
    • Cut down on the amount of alcohol you drink, if you drink at all
    • Reduce the amount of food you eat that is salt-cured, smoked, or nitrite-preserved

    Using talcum powder on the genitals is suspected to be associated with an increased risk for ovarian cancer. It is possible, however, that this risk is attributable to asbestos, a known cancer-causing agent that used to be an ingredient in many body powders until it was banned 20 years ago. Long-term studies on women who use the newer, asbestos-free products remain to be done.

    Factors have also been identified that decrease a woman’s risk. Using oral contraceptives for five or more years, for example, is known to reduce a woman’s risk for ovarian cancer. Other possible factors that can reduce the risk but are more controversial include having a tubal ligation (fallopian tubes tied to prevent pregnancy), or using aspirin or other NSAIDs over an extended period.

    The doctor will ask you about your medical history and possible risk factors for ovarian cancer, including whether or not you have a family history of the disease. Be prepared to describe your symptoms and answer questions about your family history and risk factors for cancers. For example, the doctor will want to know whether or not you’ve ever taken birth control or had fertility problems, and for how long; at what age you began menstruating; whether you’ve had children; and whether or not you’ve regularly used talcum powder on your genitals. You doctor will ask about your mother and father’s family history of ovarian, breast, uterine, colon, and other cancers.

    The doctor will give you a pelvic examination to look for evidence of ovarian cancer. During the pelvic examination, the doctor will feel inside the vagina and the rectum, and will press into the lower abdomen for lumps or growths that could be tumors.

    If the doctor suspects ovarian cancer, tests may be needed to further indicate whether cancer is present, and if so, if it has spread beyond the ovaries. If initial tests are suspicious for ovarian cancer, further tests to check for possible spread of the disease may include:

    • a transvaginal ultrasound, which often includes a “color flow doppler” evaluation of the blood flow around the ovaries. For this test, a probe is inserted into the vagina, where it emits high-frequency sound waves. The reflections of those waves create an image called a sonogram, which helps doctors visualize growths in the abdomen.
    • CT or MRI scan of the pelvis and abdominal cavity
    • chest x-ray
    • obtaining samples of fluid from the abdomen to search for cancer cells

    The blood test called CA 125 is used to help monitor the treatment of patients who have ovarian cancer. This test is most useful for tracking the progress of patients known to have ovarian cancer, and is not generally considered to be a useful diagnostic test for the disease. This is because CA 125 can reflect many different kinds of cancers, and is even found at low levels in people who are pregnant, menstruating, or who have fibroids or endometriosis.

    Surgery must be performed to be certain ovarian cancer is present, and if so, its extent. If possible, the tumor is removed during the same surgery. Surgery allows the doctor to biopsy the tumor so the cells can be viewed under a microscope. Only then can cancer be definitively diagnosed and its cell type identified. The biopsy is obtained by opening the abdomen in a procedure called a laparotomy. The doctor examines the ovaries, takes a sample of the tumor, and explores the pelvis and abdomen to see whether the cancer has spread. This operation also allows staging of the cancer, which helps determine the prognosis and treatment options. A simplified staging is as follows:

    • Stage I: cancer is confined to one or both ovaries
    • Stage II: the pelvic region surrounding the ovaries is involved; that is, cancer may have spread to other female organs, to the bladder, or to the colon
    • Stage III: cancer has spread to the abdomen or lymph nodes
    • Stage IV: cancer has spread (metastasized) to distant sites, (e.g., to the liver, lungs, or other areas outside the abdomen)

    For most women, there are no clear steps to take to avoid ovarian cancer, although some measures may help reduce one’s risk. The following steps may reduce one’s risk of ovarian cancer:

    • using birth control pills for at least five years
    • having children

    Other steps that may help to reduce the risk are:

    • eating a low-fat diet, especially low in animal fat
    • avoiding use of talcum powder in the genital region (corn starch is believed to be a safe substitute)
    • having a tubal ligation after childbearing is finished

    Regular use of aspirin or other NSAIDs has been associated with a decreased risk of ovarian cancer in some studies. Most doctors, however, do not recommend taking such medications solely to reduce cancer risk because of other health risks associated with their use, such as gastrointestinal bleeding.

    Women with a strong family history of breast or ovarian cancer may be advised to have their ovaries removed to prevent ovarian cancer. Some experts feel it is prudent for a woman to have her ovaries removed if she has a strong family history of breast or ovarian cancer; particularly if she has a BRCA 1 or BRCA 2 mutation. In such cases, removal of the ovaries, medically known as bilateral oophorectomy, should be considered between the ages of 35 and 40 if childbearing is no longer desired.

    Even after ovary removal, a woman still runs a very small chance of developing primary peritoneal carcinoma, a cancer very similar to ovarian cancer. This cancer originates in the peritoneum, the covering of the abdominal organs.

    At this time most medical organizations do not recommend routine screening of healthy women who have no significant risk factors for ovarian cancer. Unfortunately, there is not yet a good screening test for ovarian cancer that is applicable to the general population. While CA 125 measurements and transvaginal ultrasonography can indicate that a cancer may be present, they result in too many false positives for them to be useful tests for healthy women without risk factors. Because the only way to definitively diagnose ovarian cancer is with surgery, general screening would lead to too many unnecessary surgeries. Surgery involves a small but significant risk of complications, which would likely result in more deaths than lives saved.

    New potential screening tests are currently under investigation. One promising one is a blood test for LPA (lysophosphatidic acid), another tumor marker.

  • Prevention and Screening

    For most women, there are no clear steps to take to avoid ovarian cancer, although some measures may help reduce one’s risk. The following steps may reduce one’s risk of ovarian cancer:

    • using birth control pills for at least five years
    • having children

    Other steps that may help to reduce the risk are:

    • eating a low-fat diet, especially low in animal fat
    • avoiding use of talcum powder in the genital region (corn starch is believed to be a safe substitute)
    • having a tubal ligation after childbearing is finished

    Regular use of aspirin or other NSAIDs has been associated with a decreased risk of ovarian cancer in some studies. Most doctors, however, do not recommend taking such medications solely to reduce cancer risk because of other health risks associated with their use, such as gastrointestinal bleeding.

    Women with a strong family history of breast or ovarian cancer may be advised to have their ovaries removed to prevent ovarian cancer. Some experts feel it is prudent for a woman to have her ovaries removed if she has a strong family history of breast or ovarian cancer; particularly if she has a BRCA 1 or BRCA 2 mutation. In such cases, removal of the ovaries, medically known as bilateral oophorectomy, should be considered between the ages of 35 and 40 if childbearing is no longer desired.

    Even after ovary removal, a woman still runs a very small chance of developing primary peritoneal carcinoma, a cancer very similar to ovarian cancer. This cancer originates in the peritoneum, the covering of the abdominal organs.

    At this time most medical organizations do not recommend routine screening of healthy women who have no significant risk factors for ovarian cancer. Unfortunately, there is not yet a good screening test for ovarian cancer that is applicable to the general population. While CA 125 measurements and transvaginal ultrasonography can indicate that a cancer may be present, they result in too many false positives for them to be useful tests for healthy women without risk factors. Because the only way to definitively diagnose ovarian cancer is with surgery, general screening would lead to too many unnecessary surgeries. Surgery involves a small but significant risk of complications, which would likely result in more deaths than lives saved.

    New potential screening tests are currently under investigation. One promising one is a blood test for LPA (lysophosphatidic acid), another tumor marker.

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