Ovarian cancer: Adenocarcinoma of the ovary

• What is Ovarian Cancer (Adenocarcinoma of the Ovary)?
• Statistics
• Risk Factors
• Progression
• Symptoms
• Clinical Examination
• How is it Diagnosed
• Prognosis
• Treatment
• References

What is Ovarian Cancer (Adenocarcinoma of the Ovary)?

Ovarian cancer refers to cancer of the cells of the ovary. The ovaries are the organs which produce eggs for fertilization and subsequent reproduction. They also produce hormones which regulate the menstrual cycle.

About 90% of ovarian cancer arises from the cells on the outer surface of the ovary.

Statistics

Ovarian cancer accounts for about 3-4% of cancer in women. It is commonest in women between 60 and 70 years of age. It is the 8^th most common cancer diagnosed in Australian women, and the 6^th most common cause of cancer death in Australian women.

Risk Factors

Risk factors include:

• Age
• Early menarche (age of first menstruation)
• Late menopause
• Childlessness
• Prolonged ovulation induction
• Family history of ovarian or breast cancer

Protective factors include:

• Breastfeeding
• Giving birth to more than one child
• Contraceptive pill use

Progression

Ovarian cancer usually spreads within the pelvis and abdomen through the lymphatic vessels.

How is it Diagnosed

Ovarian cancer is difficult to diagnose at an early stage because symptoms are usually asymptomatic.

Unlike pap-smear for cervical cancer, where routine screening helps early detection, routine screening for ovarian cancer is not recommended due to the absence of identifiable pre-cancerous lesions.

Diagnosis is made based on:

• Clinical history
• Examination involves abdominal palpation, internal examination and examination of back passage
• Investigations – transabdominal/transvaginal ultrasound plus blood test for Ca125. Other investigations that may be considered include: blood tests for electrolytes, LFTs, CXR, barium enema.

Instructions for the tests

• Blood test for Ca125 requires no special preparation
• Transabdominal ultrasound requires a full bladder to visualise the ovaries.

Prognosis

The outcome of disease depends on the extent of the disease. If found early before the cancer spreads to surrounding organs, the disease can be successfully treated. Approximately half of women diagnosed with ovarian cancer will survive at least 5 years.

Treatment

The type of treatment depends on the stage of the disease. First-line treatment is surgical management, followed by chemotherapy then radiotherapy.

Surgical management

Surgical management is done by open surgery. This is to assess the stage of disease as well as remove the tumour. Removal of the tumour may involve removal of the ovaries, uterus and cervix, and other organs that it may have spread to. The removed specimen is sent to the laboratory to stage the disease for appropriate treatment.

Bowel preparation may be required before surgery. If the cancer has spread to the bowel, a bowel resection may be necessary. Studies have shown that the less disease left after surgery, the longer the survival time.

For young women with early disease, the uterus and the unaffected ovary may be preserved for future reproduction. This would require a careful follow-up program.

Chemotherapy

Chemotherapy in ovarian cancer prolongs short term survival and improves quality of life. It increases the 5-year survival rate from 74% to 82% in some patients with early stage disease. Chemotherapy also reduces the risk of recurrences and death in early disease if the surgery did not remove all of the disease.

Chemotherapy uses a combination of drugs to kill cancer cells and slow their growth. These drugs are listed below. The side-effects of some of these drugs will be explained by your doctors, and can usually be managed effectively by them. The therapy is usually recommended for around 6 cycles to achieve complete response.

Radiotherapy

Only a few women with ovarian cancer will have radiotherapy.

Treatment in advanced disease

In cases where surgery and chemotherapy have been unsuccessful, or where patient cannot withstand major surgery, they may be managed with palliative care. This aims to increase quality of life for the patient and family. Palliative management involves treating symptoms such as pain, nausea and bleeding, and symptoms of intestinal obstruction, as well as catering for social, psychological and spiritual needs.

Care in this area can be provided at three levels:

• General practitioners
• Specialist practitioners
• Specialist hospices of gynaecological units

References

1. CPO: Clinical practice guidelines for the management of women with epithelial ovarian cancer [online]. Camperdown, NSW: National Breast and Ovarian Cancer Centre; 18 March 2004. Available from: URL link
2. Impey L. Obstetrics and Gynecology (2nd edition). Massachusetts: Blackwell Publishing; 2004: 27-33. [Publisher]
3. Ovarian cancer: The facts [online]. Camperdown, NSW: National Breast and Ovarian Cancer Centre; Available from: URL link
4. OCG: Assessment of symptoms that may be ovarian cancer: A guide for GPs [online]. Camperdown, NSW: National Breast and Ovarian Cancer Centre; 1 August 2005. Available from: URL link
5. OCC: Epithelial ovarian cancer: Understanding your diagnosis and treatment [online]. Camperdown, NSW: National Breast and Ovarian Cancer Centre; 1 January 2005. Available from: URL link
6. Badgwell D, Bast RC Jr. Early detection of ovarian cancer. Dis Markers. 2007;23(5-6):397-410. [Abstract]
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8. Fader AN, Rose PG. Role of surgery in ovarian carcinoma. J Clin Oncol. 2007;25(20):2873-83. [Abstract]
9. Martin VR. Ovarian cancer: An overview of treatment options. Clin J Oncol Nurs. 2007;11(2):201-7. [Abstract]
10. Dann RB, Kelley JL, Zorn KK. Strategies for ovarian cancer prevention. Obstet Gynecol Clin North Am. 2007;34(4):667-86. [Abstract]
11. Salehi F, Dunfield L, Phillips KP, et al. Risk factors for ovarian cancer: An overview with emphasis on hormonal factors. J Toxicol Environ Health B Crit Rev. 2008;11(3-4):301-21. [Abstract]