Development of a Health-related Quality of Life Questionnaire for Patients with Metastatic or Localized Renal Cell Carcinoma.

Background and objective: Despite significant advances in treatments for renal cell carcinoma (RCC) over the past decade, health-related quality of life (HRQOL) assessments have not been updated to reflect these developments. The aim of our study was to refine assessment of HRQOL for patients with localized or metastatic RCC.

Methods: We conducted a four-phase international study (August 2022-October 2024). Phase 1 involved a patient survey identifying relevant HRQOL issues. In phase 2, an expert panel refined items, followed by patient advocate feedback in phase 3. Phase 4 harmonized items with the Functional Assessment of Chronic Illness Therapy library for consistency across RCC stages. Data analysis included descriptive statistics and qualitative analysis of the content.

Key findings and limitations: Of 54 items from the Functional Assessment of Cancer Therapy-Kidney Symptom Index (FKSI-19), European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30, and EuroQol Group-Five Dimension questionnaires, the metastatic RCC cohort endorsed 15 items, while the localized RCC cohort endorsed six. Expert panel review and patient advocate feedback resulted in a revised 23-item FKSI questionnaire with targeted subsets of 11 items for localized RCC and 12 items for metastatic RCC. Application of a relevance threshold of 66% ensured clinical significance but limited the sensitivity. Future studies could explore complementary approaches to refine item selection and enhance score interpretability. Study limitations include a potentially limited patient sample and reliance on patient recall of patient-reported outcomes.

Conclusions and clinical implications: We successfully developed item subsets of the FKSI-23 questionnaire that address the multifaceted impact of localized and metastatic RCC on patients' HRQOL. These two clinical settings required distinct tools for optimal measurement of HRQOL. Validation of the resulting FKSI-23 tool is under way in forthcoming clinical trials.