Participant information

  • More than 7,000 women are diagnosed with ovarian cancer and 4,000 women die from ovarian cancer in the UK each year
  • Ovarian cancer is often diagnosed when it is at a late stage and harder to treat
  • Finding a reliable screening method that picks up ovarian cancer earlier, when treatments are more likely to be effective, could help reduce deaths from the disease
  • UKCTOCS tested two different ovarian cancer screening methods, versus no screening: these were multimodal screening (annual blood tests with transvaginal ultrasound as a second line test in case of abnormality) and ultrasound screening (annual and second line tests were transvaginal scans).
  • Between April 2001-Sept 2005 a total of 202,638 postmenopausal women, aged 50-74 years from the general population joined the trial. Women who were at high-risk of familial ovarian cancer were excluded.
    • 50,640 women were in the multimodal group and had a yearly blood test. We looked for changes in a woman’s levels of a protein called CA125 until 2011.
    • 50,639 women were in the ultrasound group and had a yearly vaginal ultrasound scan to check their ovaries) till 2011
    • 101,359 women were in the no screening group
  • Women in the screened groups underwent an average of 8 annual screens till 31 Dec 2011. Overall, there were 345,570 screens in the multimodal group and 327,775 in the ultrasound group
  • Women were then followed up for 3 further years till 31 Dec 2014
  • In 2015 we released the results of the trial which showed that screening picked up 84% of all ovarian cancers diagnosed in the multimodal group and 73% of all ovarian cancers in the ultrasound group
  • Only one in four women shown to have invasive ovarian cancer, had reported symptoms commonly associated with ovarian cancer (pelvic or abdominal pain, increase in abdominal size, loss of appetite/feeling full)
  • Compared to women who had no screening, 13% more of those in the multimodal screening group who were diagnosed with ovarian cancer were at an earlier stage (stage I and II),
  • There was no difference in stage of ovarian cancer between the ultrasound and no screening groups
  • Both screening methods picked up changes that were not in fact ovarian cancer. This meant that women had unnecessary surgery together with the worry and risk of complications that goes with it:
    • In the multimodal group 14 woman had unnecessary surgery for every 10,000 women screened. This means that for each woman detected by multimodal screening to have ovarian cancer, an additional 2 women had unnecessary surgery
    • In the ultrasound group 50 woman had unnecessary surgery for every 10,000 women screened. This means that for each woman detected by ultrasound screening to have ovarian cancer, an additional 10 women had unnecessary surgery
  • There was not enough data in 2015 to be sure whether screening helped reduce deaths from ovarian cancer.
  • However, the results suggested that following up the women for a few more years would allow us to definitely decide whether screening did or did not reduce deaths from ovarian cancer
  • The trial was conducted with rigor and huge attention to detail
  • There was no further screening beyond 2011
  • We continued to follow-up the women until June 2020 adding a further 5 years of information.
  • We now have, on average, more than 16 years of follow up after recruitment, allowing us to answer definitively whether our screening approaches can reduce deaths
  • Nine and half years after end of screening, there was a 47% increase in the incidence of stage I and 24·5% decrease in stage IV in women diagnosed with ovarian cancer in the multimodal group compared to no screening. Overall, the incidence of Stage I/II was 39% higher and Stage III/IV 10% in the multimodal group lower compared to the no screening group
  • We found no difference in stage between women diagnosed with ovarian cancer in our ultrasound group compared to no screening group
  • We found no evidence that either screening approach reduced deaths from ovarian cancer, compared to no screening
  • Based on the results of this very large, well-conducted trial, we cannot recommend population screening for ovarian cancer using either the multimodal or ultrasound approach as used in UKCTOCS
  • We need a test that can detect ovarian cancer in women without symptoms earlier in its course and in a larger proportion of women than the tests used in the trial
  • Even though we were able to find more women with earlier stage disease using multimodal screening, this did not lead to lives saved. This shows that in ovarian cancer, approval of a screening test must be based upon evidence that it reduces deaths and not just evidence that it finds more individuals with early disease
  • Population screening for ovarian cancer can only be supported if a new test is shown to reduce deaths in a future randomised controlled trial
  • The UKCTOCS trial shows that women in the general population are very motivated to join randomised trials testing new screening tools, even if this means attending annual appointments over many years

At your UKCTOCS recruitment appointment which took place between 2001 and 2005 you provided written consent for:-

  1. for collection and use of your data for identification of ovarian cancer and determining death due to ovarian cancer (primary purpose)
  2. for collection and use of samples and data in future ethically approved research studies, the focus of which is the early detection and treatment of disease (secondary purpose). So far UKCTOCS participants have contributed to research for a number of different cancer types including breast cancer, colorectal cancer, endometrial (womb) cancer and pancreatic cancer in addition to ovarian cancer (click here to see further details of these and other secondary research studies).

You have given us consent to access your medical records via your GP and/or Hospital/Consultant (if you have received any medical treatment) and to obtain data held in electronic health records by the NHS. Here are copies the original documents provided to you at the time of joining UKCTOCS: Patient Information Sheet; Consent form; Data Protection Consent form.

As more than 10 years have passed since you gave consent it has been necessary for the UKCTOCS team to apply for legal permission to continue to obtain, hold and process your personal medical data. This permission (Section 251) has been granted to us by the Confidentiality Advisory Group of the Health Research Authority and forms the legal basis by which we may continue to access your medical data.

The UKCTOCS Team at the Gynaecological Cancer Research Centre are based at University College London (UCL) and UCL are the custodians (Data Controller) of all your data including that which directly identifies you. This data includes, but is not restricted to your name, date of birth, postal address, GP contact details and self-reported health related information that you provided at recruitment and through any of the questionnaires that we have sent to you. 

NHS Digital, NHS Wales, Public Health England (PHE) and N. Ireland Social Care Agency provide us with cancer registration data (cancer diagnosis and date of diagnosis), hospital episode data (diagnosis, operations/treatment and dates of hospital episodes) and, in the case of your death, date and cause of death. In order to receive this data we share with these agencies data that you provided at recruitment (name, date of birth, NHS number and postcode). These agencies use the data we share with them in order to correctly identify your cancer/death registrations and hospital episodes and return this data to us, the UKCTOCS team at UCL. 

Where your donated blood samples (serum) are used in ethically approved secondary studies we will only share anonymous data with collaborators and it will not be possible for the collaborator to identify you as an individual directly from this data nor indirectly if combined with other data.

As explained when you joined the trial and gave written consent taking part is voluntary and you are free to withdraw consent at any time and do not have to give a reason.  This will not affect any future care you receive. However, please be aware that it will not be possible to “un-share” any anonymous data or samples that have already been used in ethically approved secondary research studies. 

If you want to withdraw your consent please send an email using one of the email links below or write to: Dr Alex Gentry-Maharaj, Dr Andy Ryan or Professor Usha Menon, UKCTOCS Team, Gynaecological Cancer Research Centre, MRC CTU at UCL, Institute of Clinical Trials & Methodologies, UCL, 90 High Holborn, 2nd floor, London WC1V 6LJ, UK. Please include your full name, contact number or email, date of birth and study reference number if known.

  1. “No” to further contact: I consent for my data and samples to be used by UKCTOCS and in future approved research studies but I no longer wish to be contacted by UKCTOCS (eg surveys or questionnaires). Email:
  2. “No” to further research studies: I consent to continue to be part of UKCTOCS but I no longer wish to have my data and samples used in any future approved research studies (eg other cancers, heart disease, Alzheimer’s disease etc.) Email:
  3. “No” to UKCTOCS and further research studies: I withdraw consent for my data and samples to contribute to the UKCTOCS trial or any future research studies. Email:

If you wish to receive further information about the study or wish to withdraw consent differently from any of the above options, you can do so by contacting: 

  • Email:
  • Tel: (+44) 020 7670 4700
  • Fax: (+44) 020 7670 4909
  • Write to: Dr Alex Gentry-Maharaj, Dr Andy Ryan or Professor Usha Menon, UKCTOCS Team, Gynaecological Cancer Research Centre, MRC CTU at UCL, Institute of Clinical Trials & Methodologies, UCL, 90 High Holborn, 2nd floor, London WC1V 6LJ, UK.

The EU General Data Protection Regulation (GDPR) and the UK Data Protection Act 2018 requires that we provide all trial/study participants with additional details regarding the legal basis that allows us to hold their personal data. 

As a University,  UCL uses personally-identifiable information to conduct research to improve health, care and services. As a publicly-funded organisation, we have to ensure that it is in the public interest when we use personally-identifiable information from people who have agreed to take part in research.  This means that when you agree to take part in a research study, we will use your data in the ways needed to conduct and analyse the research study. Your rights to access, change or move your information are limited, as we need to manage your information in specific ways in order for the research to be reliable and accurate. If you withdraw from the study, we will keep the information about you that we have already obtained. To safeguard your rights, we will use the minimum personally-identifiable information possible. Health and care research should serve the public interest, which means that we have to demonstrate that our research serves the interests of society as a whole. We do this by following the UK Policy Framework for Health and Social Care Research.

If you wish to raise a complaint on how we have handled your personal data, you can contact our Data Protection Officer who will investigate the matter. If you are not satisfied with our response or believe we are processing your personal data in a way that is not lawful you can complain to the Information Commissioner's Office (ICO).

UCL's Data Protection Officer can be contacted on

Further details on UCL's privacy notice for participants in health and care reseach can be accessed by clicking on this link.

Further details on UCL's general privacy notice can be accessed by following this link.

UKCTOCS privacy notice v2.0.2

Patients in England are able to opt out of their personal confidential data being shared by NHS Digital (the Health and Social Care Information Centre HSCIC) for purposes other than their own direct care, this is known as the 'Type 2 opt-out'. This is done by registering for opt-out through your GP practice.

However, opting out will also result in withdrawing use of your data during the ongoing follow up of UKCTOCS participants. If you opt out then we will no longer receive notifications of any diseases that you are unfortunate enough to develop or any hospital admissions. This will mean that we have incomplete information on you when we reanalyse the data in 2019 to see if ovarian cancer screening can save lives.

Also lack of this information will limit the accuracy of some of the ethically approved research studies that you agreed we could undertake using your data or donated blood sample(s).

Please think very carefully before opting out. Without access to your medical records it will become increasingly difficult for cancer and disease research to be performed in the UK.

Please check with your GP practise to confirm that you are “not out” as there is evidence that some practises have opted out all of their patients without even asking!

For further details of the benefit to staying in please see: