Rationale: Health-related quality of life (HRQOL) in people diagnosed with cancer is of increasing interest as an endpoint in clinical care and research. It helps keep track of patients' functioning and wellbeing, and informs the net clinical benefit of treatment. However, gathering HRQOL information becomes increasingly harder when patients experience disease progression. Therefore we need to develop measurement strategies of HRQOL within the progressive disease setting. Objective: The overall aim of the project is to develop recommendations to optimise the measurement and analysis of HRQOL outcomes of cancer patients within the progressive disease setting. The aim of this sub-study is to identify the preferences of patients, their carers as proxies, and health-care professionals (HCPs) about the research objectives, how often and how we should assess HRQOL, and how we might limit dropout over time.

Sub-study design: An international, multi-centre study using semi-structured interviews.

Procedures: Across Europe, we aim to interview adult people diagnosed with cancer who experience progressive disease (N=30), their carers as proxies (N=30), and HCPs involved in cancer care and/or research (N=15). The UK site will aim to recruit a maximum of 10 patients and 10 proxies. Patients and carers will be interviewed twice to evaluate whether preferences change over time. Study outcomes: Findings can help in optimising the measurement and analysis of HRQOL outcomes of cancer patients in the progressive disease setting. This will help to better inform both clinical decision-making and regulatory processes.

Inclusion Criteria:

PATIENT- Adult (> 18 years of age)

• Histologically proven or radiologically diagnosed cancer
• Clinical and/or radiological progressive disease according to RECIST criteria
• Poor prognosis, i.e. expected survival time <3 years according to the treating physician PROXIES - Adult (> 18 years of age)
• Partner, relative or close friend of a patient who is eligible according to the criteria specified above

Exclusion Criteria:

• Participants without understanding of the official language of the country in which they live
• Participants with any psychiatric condition or cognitive impairment, as determined by the treating physician, that would hamper providing informed consent for research participation

Adult (> 18 years of age) attending ST James University Hospital in Leeds