Ovarian Cancer

What is Ovarian Cancer ?

After cancers of the lung, breast, and colon, primary ovarian cancer ranks as the most common cause of cancer death among American women. In women with previously treated breast cancer, metastatic ovarian cancer is more common than cancer of any other organ.

The prognosis varies with the histologic type and staging of the disease. but it's often poor because ovarian tumors are difficult to diagnose and progress rapidly. About 40% of women with ovarian cancer survive for 5 years.

Causes of Ovarian Cancer

Environmental and lifestyle factors seem to play a role in ovarian cancer. Women who live in industrialized nations are at greater risk, as are those whose diet is high in saturated fat. Other risk factors include infertility, problems or nulliparity, celibacy, exposure to asbestos and talc, a history of breast or uterine cancer, and a family history of ovarian cancer.

Primary epithelial tumors arise in the miillerian epithelium; germ cell tumors in the ovum; and sex cord tumors in the ovarian stroma. Ovarian tumors spread rapidly intraperitoneally by local extension or surface seeding and, occasionally, through the Iymphatics and the bloodstream. In most cases, extraperitoneal spread is through the diaphragm into the chest cavity, which may cause pleural effusions. Other metastasis is rare.

There are three main types of ovarian cancer:

• Primary epithelial tumors account for 90% of all ovarian cancers and include serous cystadenocarcinoma, and mucinous cystadenocarcinoma, and endometriod and mesonephric malignant tumors.
• Germ cell tumors include endodermal sinus malignant tumors, embryonal carcinoma (a rare ovarian cancer that appears in children), immature teratomas, and dysgerminoma.
• Sex cord (stromal) tumors include granulosa, cell tumors (which produce estrogen and may have feminizing effects), thecomas, and the rare arrhenoblastomas (which produce androgen and have virilizing effects).

Signs & Symptoms of Ovarian Cancer

• Abnormal menstrual cycles
• Unexplained back pain that worsens over time
• Fatigue
• Gastrointestinal symptoms (e.g., gas, long-term stomach pain, indigestion)
• Malnourished or wasted appearance
• Unusual vaginal bleeding

There may be no symptoms until late in the disease.

Diagnostic Tests

Tests ordered to help assess the patient's condition may include a complete blood count, blood chemistries, and electrocardiography.

Exploratory laparotomy, including lymph node evaluation and tumor resection, is required for accurate diagnosis and staging. Abdominal ultrasonography, a computed tomography scan, or X-rays delineate tumor size. Chest X-rays can also help identify distant metastasis and pleural effusions.

Lymphangiography can show lymph node involvement, and mammography can rule out primary breast cancer.

Liver function studies or a liver scan can help identify metastasis with ascites. Aspiration of ascitic fluid can reveal atypical cells

Laboratory tumor marker studies, such as ovarian carcinoma antigen, carcinoembryonic antigen, and human chorionic gonadotropin. are also evaluated.

Treatment

Depending on the cancer's stage and the patient's age, treatment requires varying combinations of surgery, chemotherapy, and, possibly, radiation therapy.

Surgery - Surgery for ovarian cancer may include:

• salpingo-oophorectomy - surgery to remove the fallopian tubes and ovaries.
• hysterectomy - surgical removal of the uterus.
• pelvic lymph node dissection - removal of some lymph nodes from the pelvis.

Chemotherapy - the use of anticancer drugs to treat cancerous cells. In most cases, chemotherapy works by interfering with the cancer cell’s ability to grow or reproduce. Different groups of drugs work in different ways to fight cancer cells. The oncologist will recommend a treatment plan for each individual.

Radiation therapy isn't commonly used because it causes myelosuppression, which limits the effectiveness of chemotherapy. Radioisotopes have been used as adjuvant therapy but cause small-bowel obstructions and stenosis.

Prevention Tips

The prevention of ovarian cancer is still under investigation. One recent study has looked at the benefits of chemoprevention with a retinoid, a chemical relative of vitamin A, to prevent ovarian cancer. While the results from this study are preliminary, they suggest a potential for chemoprevention in women who are at high-risk. However, most new findings have not been developed into practical methods of prevention.