Ovarian cancer

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}} Ovarian cancer is a malignant ovarian neoplasm (an abnormal growth located on the ovaries).

Contents

Causes

Ovarian cancer is the fifth leading cause of cancer death in women, the leading cause of death from gynecologic malignancies and the second most commonly diagnosed gynecologic malignancy [1]. It is idiopathic, meaning that the exact cause is unknown. The disease is more common in industrialized nations, with the exception of Japan. In the United States, females have a 1.4 % to 2.5 % (1 out of 40-60 women) lifelong chance of developing ovarian cancer.

Older women are at highest risk. More than half of the deaths from ovarian cancer occur in women between 55 and 74 years of age and approximately one quarter of ovarian cancer deaths occur in women between 35 and 54 years of age.

The risk for developing ovarian cancer appears to be affected by several factors. The more children a woman has, the lower her risk of ovarian cancer. Early age at first pregnancy, older ages of final pregnancy, and the use of some oral contraceptive pills have also been shown to have a protective effect. Ovarian cancer is reduced in women after tubal ligation.

The link to the use of fertility medication has been controversial. An analysis in 1991 raised the possibility that use of drugs tation may increase the risk for ovarian cancer. Several cohort studies and case-control studies have been conducted since then without providing conclusive evidence for such a link with the possible exception that prolonged use (> 1 year) of clomiphene citrate should be avoided.Template:Fn It will remain a complex topic to study as the infertile population differs in parity from the "normal" population.

There is good evidence that in some women genetic factors are important. Carriers of certain mutations of the BRCA1 or the BRCA2 gene (especially Ashkenazi Jewish women) are at a higher risk of both breast cancer and ovarian cancer, often at an earlier age than the general population. Patients with a personal history of breast cancer, or a family history of breast and/or ovarian cancer, may have an elevated risk. A strong family history of uterine cancer, colon cancer, or other gastrointestinal cancers may indicate the presence of a syndrome known as hereditary non-polyposis colon cancer (HNPCC), which confers a higher risk for developing ovarian cancer. Patients with strong genetic risk for ovarian cancer may consider the use of prophylactic oophorectomy after completion of child-bearing.

Other factors that have been investigated, such as talc use, asbestos exposure, high dietary fat content, and childhood mumps infection, are controversial and have not been definitively proven.

A study funded by American Cancer Society conducted at the H. Lee Moffitt Cancer Center & Research Institute has found a correlation between high levels of lysophospholipids (a type of fatty acid) with ovarian cancer patients and low levels of lysophospholipids with healthy women. This potential biomarker can be detected by a simple blood test. The blood test was 93 % accurate as predictor of ovarian cancer with less than 4 % false positives of the 117 women studied. Other indicators of ovarian cancer could be used to increase accuracy to 100 %. Template:Fn

Symptoms

Note: There may be no symptoms until late in the disease.

In particular, women should watch for symptoms occurring in groups and lasting two weeks or more.

Diagnosis

Women experiencing these symptoms might want to request a blood test called CA-125, along with a complete pelvic examination. While this test is not generally regarded as useful for large scale screening by the medical community, a high value may be an indication that the woman should receive further diagnostic screening or treatment. Normal values range from 0 to 35. Elevated levels in post-menopausal women are usually an indication that further screening is necessary. In pre-menopausal women, the test is less reliable as values are often elevated due to a number of non-cancerous causes, and a value above 35 is not necessarily a cause for concern.

Further screening may involve CT scans, trans-vaginal ultrasounds, or retesting of the CA-125 value at a later date (to see if the value is normalising, or increasing).

Physical examination may reveal increased abdominal girth and /or ascites (fluid within the abdominal cavity). Pelvic examination may reveal an ovarian or abdominal mass. The pelvic exam should include a rectovaginal component for better palpation of the ovaries.

Classification

Ovarian cancer is classified according to the histology of the tumor. Lesions differ significantly in clinical features, management, and prognosis (ICD-O codes provided where available):

Staging

Ovarian cancer staging is by the FIGO staging system and uses information obtained after surgery, which should include a total abdominal hysterectomy, removal of (usually) both ovaries and fallopian tubes, (usually) the omentum, and pelvic (peritoneal) washings for cytology. The AJCC stage is the same as the FIGO stage.

  • Stage I - limited to one or both ovaries
    • IA - involves one ovary; capsule intact; no tumor on ovarian surface; no malignant cells in ascites or peritoneal washings
    • IB - involves both ovaries; capsule intact; no tumor on ovarian surface; negative washings
    • IC - tumor limited to ovaries with any of the following: capsule ruptured, tumor on ovarian surface, positive washings
  • Stage II - pelvic extension or implants
    • IIA - extension or implants onto uterus or fallopian tube; negative washings
    • IIB - extension or implants onto other pelvic structures; negative washings
    • IIC - pelvic extension or implants with positive peritoneal washings
  • Stage III - microscopic peritoneal implants outside of the pelvis; or limited to the pelvis with extension to the small bowel or omentum
    • IIIA - microscopic peritoneal metastases beyond pelvis
    • IIIB - macroscopic peritoneal metastases beyond pelvis less than 2 cm in size
    • IIIC - peritoneal metastases beyond pelvis > 2 cm or lymph node metastases
  • Stage IV - distant metastases

Para-aortic lymph node metastases are considered regional lymph nodes (Stage IIIC).

Treatment

Surgery is the preferred treatment and is frequently necessary for diagnosis. Studies have shown that surgery performed by a specialist in gynecologic oncology usually result in a higher rate of cure. Chemotherapy is used as after surgery to treat any residual disease. Until recently, intravenous chemotherapy was used in treating patients with advanced ovarian cancer. A recent study has shown that women with advanced ovarian cancer live longer if chemotherapy is given into the abdomen. Now doctors are recommending chemotherapy delivered to the abdomen as a preferred method of treating advanced ovarian cancer. This treatment is referred to as intraperitoneal hyperthermic chemoperfusion. Chemotherapy can also be used to treat women who have a recurrence. Radiation therapy is rarely used in ovarian cancer in the United States.

Chemosensitivity testing is being done by a few labs in the USA. These labs use a variety of methods to attempt to identify chemotherapy agents that will work with an individual's cancer. However, response to chemotherapy can be much different when a tumor is removed from an individual, and many forms of purported chemosensitivity testing have not yet been shown to predict actual response. The procedure often requires that the patient contact a lab offering this service, which then ships containers ahead of surgery, so that the surgeon can send tumor samples in for testing. Costs are often not covered by insurance.

Expectations (prognosis)

Ovarian cancer is disproportionately deadly for a number of reasons. First, symptoms are vague and non-specific, so women and their physicians frequently attribute them to more common conditions. By the time the cancer is diagnosed, the tumor has often spread beyond the ovaries.

Also, ovarian cancers shed malignant cells that frequently implant on the uterus, urinary bladder, bowel, and lining of the bowel wall (omentum). These cells can begin forming new tumor growths before cancer is even suspected.

Second, because no cost-effective screening test for ovarian cancer exists, more than 50 % of women with ovarian cancer are diagnosed in the advanced stages of the disease.

Ovarian cancer is rarely diagnosed in its early stages; it is usually quite advanced by the time diagnosis is made. The outcome is often poor. The five-year survival rate for all stages is only 35 % to 38 %. If, however, diagnosis is made early in the disease, five-year survival rates can reach 90 % to 98 %. Germ Cell Ovarian Cancer has a much better prognosis, but is rarer.

Despite this poor prognosis, patients should keep in mind that all such studies are retrospective in nature: i.e., they can only look into past results. Therefore they cannot take into account the benefits on survival that newer therapies may provide.

Complications

  • spread of the cancer to other organs
  • progressive function loss of various organs
  • ascites (fluid in the abdomen)
  • blockage of the intestines

Victims of ovarian cancer

References

Template:FnBrinton LA et al. Ovulation induction and cancer risk. Fertil Steril 2005;83:261-74.

Template:FnThe study is published in the July 7, 2004 journal of Cancer Epidemiology, Biomarkers & Prevention.

Template:FnAmerican Association for Clinical Chemistry (2002). CA-125 At a Glance at Lab Tests Online. Retrieved on March 1, 2005.

See also

External links

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