Ovarian cancer affects many women around the world and its mortality rates are higher compared to other cancers. The main reason behind this seems to be the lack of early diagnosis. Most of the women detected with ovarian cancer are already in their advanced stages.
A recent study published in the Journal The Lancet
has reported that a new blood test can detect ovarian cancer. The findings belong to the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS) which is currently conducting the world's largest trial on ovarian cancer.
‘Risk of Ovarian Cancer Algorithm (RACO) detects the presence of a protein called CA125, which is often found at high levels in women who have ovarian cancer.
The trial has been conducted by Dr. Ian Jacobs, the lead researcher along with his collegues who have analyzed more than 200,000 women across the UK aged between 50 and 74.
Of this, 100,000 women, formed the 'control' group, 50,000 women belonged to the second group who were screened every year with an ultrasound scan, to look for abnormalities in their ovaries that could be a sign of cancer and another 50,000 women belonged to the third group who were given an annual blood test to measure the levels of a protein called CA125, which is often found at high levels in women who have ovarian cancer.
The protein can also raise to higher levels during pregnancy and menstruation. Therefore, using a cut-off of CA125 levels can vary widely from woman to woman. To overcome this problem, researchers have come with a new method called 'Risk of Ovarian Cancer Algorithm' (ROCA).
Using ROCA, researchers tested the presence of this protein in the women screened. Women who had 'normal' ROCA scores continued with annual screening while women at 'intermediate risk' had their blood test repeated after 3 months; and those at 'elevated risk' had repeated blood tests, and an ultrasound, within 6 weeks.
Based on this, the researchers estimate that for every 10,000 women screened every year with a blood test, about 15 lives could be saved. But still the test is not considered to be an effective one.
Researchers hope that this can give a better idea about whether a woman might have an early-stage ovarian cancer. Researchers concluded that the mortality reduction did not reach conventional levels of significance in either screening arm in the primary analysis.
Jacobs is currently working with a company to develop the CA125 algorithm into a commercial test. But he adds that still more work needs to be done to make it as a national screening test like the mammogram.
He said "A key step in the jigsaw [puzzle] that is about 85% assembled now. It is a paradigm shift in showing that you can actually intervene by screening and change the natural history of the disease and likely save lives."
Reference: Ian J Jacobs, Usha Menon et al. "Ovarian cancer screening and mortality in the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS): a randomised controlled trial," The Lancet, 2015, http://dx.doi.org/10.1016/S0140-6736(15)01224-6