Patient Education

Ms Angelina Jolie has spoken about her decision to have preventive surgery for ovary cancer in Mar 2015 in the New York Times. She is known to carry a hereditary mutation in the BRCA1 gene, which increased her risk for ovarian cancer and breast cancer. In addition, the type of breast cancer commonly associated with BRCA1 mutation carriers is triple negative breast cancer (TNBC) which tends to be more aggressive.

What about monitoring or screening for ovarian cancer?

Ovarian cancer is often detected late (stage 3). The natural question most people would ask is that if the risk for ovary cancer is elevated, then why not just monitor with regular scans or blood tests?  Ovarian cancer screening measures currently available (transvaginal ultrasound examination and serum CA 125 concentration) have limited ability to detect early ovarian cancer. They have not been shown to reduce ovarian cancer mortality. However, for women who choose to defer preventive surgery, it is something that is discussed as part of preventive measures. CA-125 is a cancer antigen or protein detectable in the blood (so it is convenient to check). It is used as a tumour marker or biomarker, and may be increased in some patients with cancer but also in other benign (non-cancer) conditions.

Prophylactic salpingo-oophorectomy or preventive removal of the ovaries and fallopian tubes

The surgery that is done removes the ovaries, and the fallopian tubes. The fallopian tubes carry the egg or ovum to the uterus. Several studies have shown a significant (more than 80%) risk reduction in ovarian cancer following risk-reducing oophorectomy.  In addition, when the “normal” ovaries that are removed are examined under a microscope, the histology shows a wide range of proliferation and some irregular changes as well as occult ovarian cancers and primary fallopian tube tumours. This lends further support for the preventive removal of the ovaries and the fallopian tubes at surgery.

Preventive removal of ovaries benefits breast cancer risk in BRCA1 and BRCA2 mutation carriers

A study involving 483 women with disease-associated germline BRCA1/2 mutations were studied for the occurrence of breast cancer. There was about 50% reduction in the risk for breast cancer in those women who had preventive bilateral prophylactic oophorectomy.

What are the disadvantages of prophylactic salpingo-oophorectomy?

Some questions regarding preventive ovarian surgery remain, such as the optimal timing for these procedures and optimal long-term surveillance. There are also some differences in recommendations from different organisations but generally it is after completion of family planning.  Removing the ovaries would put a woman into menopause (surgical menopause) because the major source of female hormones is from the ovaries. The side effects of surgical menopause may include:

• vasomotor symptoms such as hot flushes,

• vaginal dryness,

• osteoporosis, and

• increased risk for heart disease.

Although the removal of the ovaries and fallopian tubes reduce the risk for ovarian cancer, the peritoneum remains at risk for primary peritoneal cancer, with rates of approximately 2%-4% following surgery.  Primary peritoneal cancer or carcinoma is also known as extra-ovarian serous carcinoma, is a cancer of the lining cells of the peritoneum or abdominal cavity. Ovarian and peritoneal epithelium share a common embryonal origin and it is thought that these may give rise to cancer in susceptible BRCA 1 or BRCA 2 mutation carriers.

Genetic testing

At OncoCare Cancer Centre, Singapore, genetic counselling with our specialist oncology consultants is available and if needed, genetic testing is offered, if there should be concerns that hereditary cancer risk exists in the family. The process of genetic counselling provides patients and their families with information on cancer risks, and the implication of genetic testing information to work towards a prevention strategy for cancer.

“Expert knowledge means better care for cancer”

Written by:

Dr Peter Ang
MBBS (Singapore)
MMed (Int Med)
MRCP (UK)
FAMS (Medical Oncology)