Ovarian Cancer

Cancer of the ovary  is the most common cause of death from gynaecological cancer.  While it is the eight most common cancer amongst Australian women it is the sixth most common cause of of death.  While the routine statistics do not differentiate between epithelial , germ cell and sex-cord stromal tumours, over 90% are epithelial in origin especially in women over 40 years of age.  Below 40 years the number of epithelial tumours is low and germ-cell tumours relatively more common.

Some interesting statistics with respect to ovarian cancer for the year 1999 may help put some of these things in perspective:

Risk Factors

Some well designed studies have established some of the risk factors for this disease.  However, for a number of parameters further studies are needed.  Very briefly the following parameters appear to be associated with an increased (+), decreased (-) or uncertain (+/-) change in the incidence of ovarian cancer.

Screening for Ovarian Cancer

There is a good deal of interest and many studies on this topic, however, to date there is no proven screening tool(s) for epithelial ovarian cancer.  With such a poor survival result and the fact that 70% of patients present with advanced (stage III or stage IV) disease there would be great benefits to flow from a feasible screening method(s).  In cases where the disease is confined to the ovaries, five year survival figures  of over 80% are possible.

Ultrasound

Studies using either or both of abdominal &/or trans-vaginal ultrasound have high false negative rates due to their inability to reliably differentiate between benign and malignant disease.  While Doppler ultrasound has been used to try and overcome this differentiation the results have been mixed.

CA125

This is a protein which is detectable in the serum.  The test is non-specific being raised in other benign conditions including fibroids, endometriosis, any peritoneal inflammation, renal disease and some liver disease.  The levels are also affected by  smoking, caffeine consumption, age, menopausal status and the presence of other cancers.

Elevated levels are only found in a proportion of patients with ovarian cancer:

Current studies are looking at combinations of parameters such as CA125 and other markers plus ultrasound to try and improve sensitivity and specificity.

Current Screening Recommendations

Currently there is no national or international study which recommends routine population screening  for ovarian cancer.  The only justification may be in women who are a significantly increased risk because of family history or proven genetic mutation carriers who are at increased risk.