Screening for ovarian cancer could lead to earlier detection and thereby significantly reduce the number of deaths from the disease, early data from the UKCTOCS (UK Collaborative Trial of Ovarian Cancer Screening) study suggest.

Ovarian cancer is often referred to as a ‘silent killer’ because a lack of early symptoms associated with the disease means patients are generally diagnosed in the later stages, leading to a delay in medical intervention and therefore less chance of survival.

Currently, around 70% of women with ovarian cancer – the fourth biggest cause of cancer deaths in women in the UK - are diagnosed when their disease has reached an advanced stage and has spread to other parts of the body, leaving their chances of survival at just 20%-30%.

However, the chance of surviving the disease rockets to 90% if it is caught in the early stages, and so researchers of UKCTOCS - which is funded by the Medical Research Council and has enrolled around 200,000 women aged 50-74 in the UK - are currently trying to determine whether a cancer screening programme could help boost earlier detection and therefore improve current survival rates.

Half detected were in early stage
According to preliminary results of the study, published in Lancet Oncology, out of 100,000 women screened ovarian cancer or borderline tumours were detected in 87 and missed in 13 (who then developed the disease up to a year later). Furthermore, out of the 58 cancers screening picked up, 48% were in the early stages.

Screening in the UKCTOCS trial is being undertaken via a blood test for the protein CA125 - levels of which are often higher in the presence of ovarian cancer - to help calculate a woman’s risk of having the disease, or through a transvaginal ultrasound to look for any physical abnormalities.

In the blood test arm, 97 women who were considered at high risk from ovarian cancer had their ovaries removed, of which 42 tested positive for the disease. In the ultrasound group, 845 had their ovaries removed and 45 were diagnosed with the disease.

The high number of patients undergoing surgery after ultrasound is of some concern, and the researchers suggest that this could be due to the relatively large number of older women with benign cysts on their ovaries, which can often only be diagnosed through tissue examination.

It is hoped that findings of the study, which is scheduled to run until 2014, will ultimately pave the way for a national screening programme for the disease. However, while these early results are certainly encouraging, lead investigator Professor Ian Jacobs, director of the UCL (University College London) Institute for Women’s Health, says there is still a “long way to go before we have firm evidence as to whether or not screening is able to detect cancer early enough to save lives”.