Results from a 14 year trial to assess if regular blood tests could help detect ovarian cancer has reported encouraging results, with twice as many cases of the cancer detected compared to conventional methods.
According to the trial regular blood tests can detect 86% of ovarian cancers before the point at which women normally would be diagnosed. Scientists conducting the trial are very positive and hope it could lead to a national screening programme.
One of the problems with ovarian cancer is that it is often not diagnosed until the later stages of the disease. Its symptoms can include loss of appetite, abdominal pain, bloating and discomfort, which are common symptoms for a wide range of medical conditions making diagnosis difficult.
The ground breaking medical trial was carried out over 14 years, from 2001, in the UK and is the largest of its kind in the world for ovarian cancer screening. Led by University College London (UCL) it involved more than 200,000 post-menopausal women aged 50 and over. The trial involved tracking changing levels of a protein called CA125 in the blood. It is known that ovarian tumours secrete high levels of CA125, which is already used as a test if patients have symptoms. But the trial differs to a one off test as by tracking a women’s levels of CA125 over time a baseline level for each woman could be determined, and then if the levels became elevated the women were sent for further tests including ultrasound scans.
The trial results, published in the Journal of Clinical Oncology, showed 86% of cancers were picked up. The question now is whether the blood tests detected the cancers early enough to save lives. For a screening programme to be effective it needs to be able to detect the disease earlier and have an impact on treatment and survival outcomes. Like most cancers treatment is more likely to be successful if the tumour is picked up early. The data is now being analyses to determine if the tumours were picked up early enough to actually save lives, and a report is expected in the Autumn.
Researchers are hopeful that the data will show that monitoring CA125 levels is successful in detecting tumours early enough to save lives and that it could be implement by the NHS as a screening for ovarian cancer. Previous studies have questioned the benefit of screening programmes for ovarian cancer, but this trial, the largest in the world, is meant to produce the definitive verdict.
Cancer Research UK said the prospect of a blood test was “exciting”, but added that more work was needed to confirm whether the new method would save lives. Further results from the ultrasound arm of the trial, and the impact of screening on cancer death rates, are expected later this year.