Ovarian cancer trial boosts hope of screening programme

Ovarian cancer trial boosts hope of screening programme

Hopes of an ovarian cancer screening programme have been given a major boost with the discovery of a new test that can detect twice as many ovarian cancers as conventional methods. The technique tracks changing levels of a protein in the blood called CA125 which is linked to ovarian cancer. It then uses a computer programme to interprets the variations, predicting the risk of developing the disease based on factors including age, the original level of the protein and how that changed over time.


In the world's largest ovarian cancer screening trial, the new method correctly diagnosed 86 per cent of women with invasive epithelial ovarian cancer (iEOC). Ovarian cancer is the fifth most common cancer among women, with 7,000 new diagnoses in the UK alone each year.


While breast cancer kills almost three times as many, those diagnosed with ovarian cancer are more likely to die earlier. Fewer than 50 per cent surive for five years. There are few symptoms which are difficult to detect in the early stages - they include a bloated stomach and abdominal pain.


The 14-year UK Collaborative Trial of Ovarian Cancer Screening, led by University College London, recruited 202,638 post-menopausal women aged 50 and over who were randomly assigned different screening strategies. The standard blood test, which uses a fixed cut-off point for CA125, would have been expected to identify fewer than half those diagnosed in this trial, according to results from previous studies and clinical practice.


The report states: "The impact of such screening on ovarian cancer mortality will only be known in 2015 when follow up is complete.


"However, our current findings are of immediate importance as they highlight the need to examine serial change in biomarker levels in the context of screening and early detection of cancer. Reliance on predefined single threshold rules may result in biomarkers of value being discarded."


Professor Usha Menon, the study's co-principal investigator and trial co-ordinator at UCL, said: "There is currently no national screening programme for ovarian cancer, as research to date has been unable to provide enough evidence that any one method would improve early detection of tumours.


"These results are therefore very encouraging. They show that use of an early detection strategy based on an individual's CA125 profile significantly improved cancer detection compared to what we've seen in previous screening trials."


Prof Menon said the trial had safely and effectively delivered screening for more than a decade across 13 NHS Trusts.


But she added: "While this is a significant achievement, we need to wait until later this year when the final analysis of the trial is completed to know whether the cancers detected through screening were caught early enough to save lives."


The study, published in the Journal of Clinical Oncology, assessed 46,232 trial participants who continued to have regular screening checks after an initial test. Their blood was tested once a year for CA125 levels before the computer programme was used to predict their risk of ovarian cancer.


Professor Ian Jacobs, chief UKCTOCS investigator and president of the University of New South Wales in Australia, who helped develop the statistical technique and conceived the trial, said: "CA125 as a biological marker for ovarian cancer has been called into question.


"Our findings indicate that this can be an accurate and sensitive screening tool, when used in the context of a woman's pattern of CA125 over time. What's normal for one woman may not be so for another.


"It is the change in levels of this protein that's important. My hope is that when the results of UKCTOCS are available this approach will prove capable of detecting ovarian cancer early enough to 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.


Dr James Brenton, ovarian cancer expert at Cancer Research UK, said: "A blood test to find women at risk of ovarian cancer is an exciting prospect, but this work still needs to be tested in women to see if it can save lives."


Athena Lamnisos, chief executive of the women's cancer charity The Eve Appeal, said: "These latest results are exciting and point towards the strides that we're making in more accurately predicting individual risk of developing cancer."



By Victoria Ward,


The Telegraph, Monday 04 May 2015




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