Approximately 7,400 new cases of ovarian cancer are diagnosed each year in the United Kingdom (UK), and with over 4,000 women dying from the disease each year it is a particularly lethal form of cancer. The symptoms for ovarian cancer are not well known and vague, and most women are diagnosed at a late stage when the cancer has already spread around the abdominal cavity with poor prognosis. Novel methods are needed to improve earlier detection and thereby improve survival from this disease.

The Cancer Loyalty Card Study (CLOCS) proposes to use loyalty card data from two participating high street retailers to investigate purchase behaviour as an opportunity for cancer symptom surveillance. The investigators aim to conduct a case-control study of ovarian cancer patients matched with women without ovarian cancer and to explore public preferences for how to communicate potential outcomes of the commercial and health data linkages back to individuals.

Eligible participants will be women in the UK who own at least one loyalty card with the participating high street retailers. Of these women, those who have been diagnosed with ovarian cancer are eligible to participate in the study as cases, while women who have not been diagnosed with ovarian cancer are eligible to participate as controls.

Upon choosing to participate, all participants will be asked to complete a short questionnaire about well-established ovarian cancer risk factors and common symptoms either in the clinic (cases) or online/from a packet in the mail(controls). This information will be used in risk assessment for ovarian cancer of participants, which will be used at the analysis stage.

Purpose and Design

The Cancer Loyalty Card Study (CLOCS) is addressing whether or not data already collected by high street retailers can detect significant changes in purchase behaviours of ovarian cancer patients prior to their diagnosis. The investigators aim to conduct a case-control study of ovarian cancer patients matched with women who do not have ovarian cancer. The study aims to recruit at least 500 recently diagnosed ovarian cancer patients and at least 500 healthy women as controls and collate up to 7 years of prior purchase data.

This is a database only study.

Recruitment

Loyalty card holders will be invited to join the study by email and post from the high street retailers and can choose to sign up via the CLOCS website or via post by returning the consent form to the study team through the mail. There will also be a press release about the study inviting loyalty card holders to visit the CLOCS website for more information and join the study. Women, 18 years or older, who have a loyalty card at the participating high street retailers are eligible to join. Women with ovarian cancer and who own at least one of the participating high street retailer's loyalty cards will be recruited in a clinic by a member of their healthcare team where the study is open. Any woman considering joining the study can contact the research team using the contact details on the information sheet.

Consent

Ovarian cancer patients will be given the information sheet and consent form in the clinic by a member of their healthcare team. They can take as much time as they need to read through the information sheet. If they choose to participate, they can complete the consent form whenever is convenient for them and return it to the CLOCS team in the free post envelope provided to them in the clinic.

Women without ovarian cancer will be presented with the information sheet and consent form in an email or letter in the mail from their high street retailer if they hold a loyalty card with them and return them to the CLOCS team in a free post envelope. They can also find the information sheet and consent form on the CLOCS website and consent online.

Methods

Consenting participants will complete a brief questionnaire about ovarian cancer risk factors, which will also be returned to the CLOCS team through the mail or on the website (healthy volunteers only). Participants with ovarian cancer will also have a clinical form for a member of their clinical team to complete in the clinic. This will be sent to the CLOCS team along with their consent and risk factor questionnaire in the free post envelope. Two ovarian cancer patients have reviewed all questionnaires and CLOCS documents and expressed their approval. Women without ovarian cancer from the general UK population have also reviewed the risk factor questionnaire and expressed their approval saying the questionnaire is 'easy to understand' and 'straightforward'.

If participants consent to be re-contacted by the CLOCS team for future studies or for loyalty card detail clarification,they will provide either a contact email or phone number. There is no further action needed from participants once they complete their consent form and questionnaire (and clarify loyalty card details if necessary)

Inclusion Criteria:

• Women, at least 18 years old, recently diagnosed with ovarian cancer (preferably recruited just after diagnosis and during treatment period,but are still eligible if diagnosed up to 2 years prior, at the latest) who hold at least one participating high street retailer loyalty card are eligible to join the CLOCS as cases.

Women, at least 18 years old, who have not been diagnosed with ovarian cancer and hold at least one participating high street retailer loyalty card are eligible to join the CLOCS as controls.

Exclusion Criteria:

• Women under the age of 18 years and, since this is a study about ovarian cancer,men will not be eligible to join this study. Women who do not own loyalty cards with the participating high street retailers are not eligible to join this study.

Ovarian cancer is a female only cancer.

All participants will be females in the UK who are at least 18 years old and who own at least one of the participating high street retailer loyalty cards. Participants who have been diagnosed with ovarian cancer are considered cases. Participants who do not have ovarian cancer are considered controls.

Only aggregated and anonymised survey data will be shared with other researchers after publication. No sensitive individual level data will be shared.

From the 306 cases, 183 cases returned their questionnaires and one was excluded.

From 657 controls, 230 were excluded for not meeting the inclusion criteria, other reasons (duplicate test submissions) and withdrawl.

Participant numbers as per Table 1

There were no adverse events to collect as there was no intervention.

No adverse events were collected as this was an observational study with no interventions. Therefore, all events are 0 as this was not applicable to our study. The study did not collect information on any adverse events related or not related to the disease or any medical treatment administered as part of their standard of care.