Prevalence of psychological distress and associated factors among patients undergoing comprehensive genomic profiling testing: protocol for a multicentre, prospective, observational study

Introduction: Since May 2019, comprehensive genomic profiling (CGP) has been covered by Japan's health insurance system for patients with solid tumours that have progressed on standard chemotherapy, rare tumours or tumours of unknown primary origin. Although CGP has the potential to identify actionable mutations that can guide the selection of genomically matched therapies for patients with advanced cancer and limited treatment options, less than 10% of patients benefit from CGP testing, which may have a negative impact on patients' mental status. The aim of this study is to investigate the prevalence of psychological distress and associated factors among patients with advanced cancer who are undergoing CGP testing across Japan.

Methods and analysis: This multicentre, prospective cohort study will enrol a total of 700 patients with advanced cancer undergoing CGP testing. Participants will be asked to complete questionnaires at three timepoints: at the time of consenting to CGP testing (T1), at the time of receiving the CGP results (T2; 2-3 months after T1) and 4-5 months after T2 (T3). Primary outcome is the prevalence of depression as measured by the Patient Health Questionnaire-9 at the three timepoints. Secondary outcomes are the prevalence of anxiety and Quality of Life Score. Associated factors with psychological distress will also be examined, including knowledge about CGP, attitudes, values and preferences towards CGP, satisfaction with oncologists' communication and patient characteristics as well as medical information including CGP test results and genomically matched therapies if provided. The prevalence of depression and anxiety will be estimated using the unadjusted raw rates observed in the total sample. Longitudinal changes in measures will be explored by calculating differences between the timepoints. Multivariate associations between variables will be examined using multiple or logistic regression analysis depending on the outcomes to adjust for confounders and to identify outcome predictors.

Ethics and dissemination: This study was approved by the Institutional Review Board of the National Cancer Center Japan on 5 January 2023 (ID: 2022-228). Study findings will be disseminated through peer-reviewed journals and conference presentations.

Trial status: The study is currently recruiting participants and the enrolment period will end on 31 March 2025, with an expected follow-up date of 31 March 2026.

Trial registration number: UMIN000049964.