Regular screening for ovarian cancer at a population level did not reduce deaths from the disease, according to a large-scale UK trial.
The findings, published in the journal The Lancet, are based on data from more than 200,000 women who were followed up for 16 years.
Two screening methods were examined in the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS): a yearly ultrasound scan, or an annual blood test alongside the ultrasound scan – known as multimodal screening.
While multimodal testing picked up some cancer cases at an early stage, the researchers said neither screening method translated into more lives being saved.
Based on their findings, the experts said they do not recommend regular ovarian cancer screening for the general population using the two existing methods but added those experiencing symptoms should consult their doctor so they can get early access to treatment, if needed.
Professor Mahesh Parmar, director of the Medical Research Council (MRC) clinical trials unit at University College London (UCL) and a senior author on the paper, said: “There have been significant improvements in the treatment of advanced disease in the last 10 years, since screening in our trial ended.
“Our trial showed that screening was not effective in women who do not have any symptoms of ovarian cancer; in women who do have symptoms early diagnosis, combined with this better treatment, can still make a difference to quality of life and, potentially, improve outcomes.
“On top of this, getting a diagnosis quickly, whatever the stage of the cancer, is profoundly important to women and their families.”
More than 4,000 women die from ovarian cancer each year in the UK.
The disease is hard to detect in its early stages due to its vague symptoms, such as constipation, bloating, feeling full quickly when eating and back pain.
The UKCTOCS trial was designed to see whether the existing screening methods could cut deaths by picking up ovarian cancer earlier, when treatments are more likely to be effective.
Women aged 50-74 were enrolled in the trial between 2001 and 2005 and randomly allocated to one of three groups: no screening, vaginal ultrasound screening, and multimodal screening.
The blood test in the multimodal screening measures levels of a protein called CA125 that is often elevated in the blood of women who have ovarian cancer.
The ultrasound scan is used to look for abnormalities in the ovaries.
Around 39% more early-stage cancers were detected through blood test screening, the researchers said, compared to the no-screening group.
There was no difference in the stage of cancers detected in the ultrasound group compared to the no screening group, they added.
Professor Usha Menon, of the Medical Research Council (MRC) clinical trials unit at University College London (UCL) and lead investigator of UKTOCS, said: “UKCTOCS is the first trial to show that screening can definitely detect ovarian cancer earlier.
“However, this very large, rigorous trial shows clearly that screening using either of the approaches we tested did not save lives.
“We therefore cannot recommend ovarian cancer screening for the general population using these methods.
“We are disappointed as this is not the outcome we and everyone involved in the trial had hoped and worked for over so many years.
“To save lives, we will require a better screening test that detects ovarian cancer earlier and in more women than the multimodal screening strategy we used.”
Commenting on the research, Michelle Mitchell, Cancer Research UK’s chief executive, said: “Trials don’t always find the result we had hoped for, but we need long-term studies like this to know whether new tests save lives.
“Cancer Research UK will continue to fund vital research into aggressive forms of ovarian cancer so we can reduce the impact of this disease.
“Screening is for people without symptoms, so it’s still important that if you notice unusual or persistent changes to talk to your doctor.”
