Ovarian cancer

From Wikipedia, the free encyclopedia

Ovarian cancer
Classifications and external resources
ICD-10 C56.
ICD-9 183
ICD-O: varied
DiseasesDB 9418
MedlinePlus 000889
eMedicine med/1698 

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

Contents

[edit] Causes

Ovarian cancer is the fifth leading cause of cancer death in women, the leading cause of death from gynecological malignancy, and the second most commonly diagnosed gynecologic malignancy [1].

It is idiopathic, meaning that the exact cause is usually 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) lifetime 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 low dose 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, such as Clomiphene citrate, has been controversial. An analysis in 1991 raised the possibility that use of drugs 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. [2] 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 (more frequent is some populations (e.g. 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, especially if at a young age, 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, also known as Lynch II syndrome), 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.

A Swedish study, which followed more than 61,000 women for 13 years, has found a significant link between milk consumption and ovarian cancer. According to the BBC, "[Researchers] found that milk had the strongest link with ovarian cancer - those women who drank two or more glasses a day were at double the risk of those who did not consume it at all, or only in small amounts." [3]

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 the 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 %.[4]

"Associations were also found between alcohol consumption and cancers of the ovary and prostate, but only for 50 g and 100 g a day."[5]

[edit] 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):

[edit] Staging

Ovarian cancer staging is by the FIGO staging system and uses information obtained after surgery, which can 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).

[edit] 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 an improved outlook. Improved survival is attributed to more accurate staging of the disease and a higher rate of aggressive surgical excision of tumor in the abdomen by gynecologic oncologists as opposed to general gynecologists and general surgeons.

The type of surgery depends upon how widespread the cancer is when diagnosed (the cancer stage), as well as the type and grade of cancer. The surgeon may remove one (unilateral oophorectomy) or both ovaries (bilateral oophorectomy), the fallopian tubes (salpingectomy), and the uterus (hysterectomy). For some very early tumors (stage 1, low grade or low-risk disease), only the involved ovary and fallopian tube will be removed (called a "unilateral salpingo-oophorectomy," USO), especially in young females who wish to preserve their fertility. In advanced disease as much tumor as possible is removed (debulking surgery). In cases where this type of surgery is successful, the prognosis is improved compared to patients where large tumour masses (more than 1 cm in diameter) are left behind.

Chemotherapy is used as after surgery to treat any residual disease. At present many oncologists are still recommending systemic chemotherapy including a platinum derivative with a taxane as a preferred method of treating advanced ovarian cancer. However, randomized, multicenter clinical trials are beginning to clearly show that Intra-peritoneal chemotherapy produces longer survival times. As this therapy may not always be available in local hospitals, women should consult doctors based in nationally recognized centers as soon after diagnosis as possible in order to select the most effective treatment plan. Chemotherapy can also be used to treat women who have a recurrence.

Three large randomized studies of the Gynecologic Oncology Group have suggested that chemotherapy regimens delivered partly via direct infusion into the abdominal cavity (intraperitoneal or "IP") improve median survival time over regimens that are only given intravenously (in the vein or "IV"). Reported toxicities are generally higher and the advantages of IP chemotherapy are still debated among specialists.

Radiation therapy is not effective for advanced stages because a high dose can not be delivered because vital organs are in the radiation field.

Chemosensitivity and chemoresistance testing is being done by laboratories in the USA, Europe, and Asia. Unfortunately these methods have not contributed to improved results and better survival.

[edit] Symptoms

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

[edit] Diagnosis

Ovarian cancer at its early stages(I/II) is difficult to be diagnosed until it spreads and advances to later stages(III/IV). It is due to the fact that most of the common symptoms are non-specific.

The blood test called CA-125 is useful in differential diagnosis and in follow up of the disease; yet, it has not been shown to be an effective method to screen for early-stage ovarian cancer and is currently not recommended for this use.

A pelvic examination, including CT scan, trans-vaginal ultrasound, is also of utility. 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 can include a rectovaginal component for better palpation of the ovaries.

[edit] Expectations (prognosis)

Ovarian cancer has a poor prognosis. It is disproportionately deadly because symptoms are vague and non-specific. More than 60% of patients presenting with this disease already have stage III or stage IV disease, when it has already spread beyond the ovaries.

Ovarian cancers shed malignant cells into the naturally occurring fluid within the abdominal cavity. These cells then have the potential to float in this fluid and frequently implant on other abdominal (peritoneal) structures included 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.

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

[edit] Complications

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

[edit] Notable women with ovarian cancer

[edit] See also

[edit] References

  1. ^ The Merck Manual of Diagnosis and Therapy Section 18. Gynecology And Obstetrics Chapter 241. Gynecologic Neoplasms
  2. ^ Brinton LA et al Ovulation induction and cancer risk. Fertil Steril 2005;83:261-74.
  3. ^ BBC News Milk link to ovarian cancer risk 29 November 2004
  4. ^ Journal of Cancer Epidemiology, Biomarkers & Prevention July 7, 2004
  5. ^ Alcohol consumption and cancer risk

[edit] External links

Tumors (and related structures), Cancer, and Oncology edit
Benign - Premalignant - Carcinoma in situ - Malignant

Topography: Anus - Bladder - Bone - Brain - Breast - Cervix - Colon/rectum - Duodenum - Endometrium - Esophagus - Eye - Gallbladder - Head/Neck - Liver - Larynx - Lung - Mouth - Pancreas - Penis - Prostate - Kidney - Ovaries - Skin - Stomach - Testicles - Thyroid

Morphology: Papilloma/carcinoma - Choriocarcinoma - Adenoma/adenocarcinoma - Soft tissue sarcoma - Melanoma - Fibroma/fibrosarcoma - Metastasis - Lipoma/liposarcoma - Leiomyoma/leiomyosarcoma - Rhabdomyoma/rhabdomyosarcoma - Mesothelioma - Angioma/angiosarcoma - Osteoma/osteosarcoma - Chondroma/chondrosarcoma - Glioma - Lymphoma/leukemia

Treatment: Surgery - Chemotherapy - Radiation therapy - Immunotherapy - Experimental cancer treatment

Related structures: Cyst - Dysplasia - Hamartoma - Neoplasia - Nodule - Polyp - Pseudocyst

Misc: Tumor suppressor genes/oncogenes - Staging/grading - Carcinogenesis/metastasis - Carcinogen - Research - Paraneoplastic phenomenon - ICD-O - List of oncology-related terms

In other languages