A Prospective Study to Validate the Functional Assessment of Cancer Therapy (FACT) for Epidermal Growth Factor Receptor Inhibitor (EGFRI)-induced Dermatologic Toxicities FACT-EGFRI 18 Questionnaire: SWOG S1013

Abstract

Background Papulopustular rash is a common class effect of epidermal growth factor receptor inhibitors (EGFRI) that can affect patients’ health-related quality of life and cause disruptions to treatment. SWOG S1013 (NCT01416688) is a multi-center study designed to validate the Functional Assessment of Cancer Therapy EGFRI 18 (FACT-EGFRI 18) using 7-items from the National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) version 4.0 to assess EGFRI-induced skin-related toxicities and their impact on functional status. Methods Patients with a diagnosis of colorectal or lung cancer to receive EGFRI therapies for at least 6 weeks were enrolled. Patient self-assessments using the FACT-EGFRI 18 were completed prior to undergoing CTCAE assessment by trained clinicians at baseline, weekly × 6, and then monthly × 3. The psychometric properties of the FACT-EGFRI 14 (skin toxicity items only) and 18 (plus 2 nail and 2 hair items) were established based on criterion validity, known groups validity, internal consistency reliability, and responsiveness to change. Results Of the 146 registered patients, 124 were evaluable. High Cronbach’s alpha (\u3e 0.70) for both FACT-EGFRI 14 and FACT-EGFRI 18 scores across assessment times were observed. Although agreement (i.e. criterion validity) between individual and summary scales of the FACT-EGFRI 18 for assessing skin toxicity was good, agreement with the clinician-reported CTCAE was only fair. The minimal important difference was determined to be 3 points. The results also demonstrated responsiveness to symptom change. Discussion Based on the results of this multi-center validation study, the FACT-EGFRI 18 patient-reported outcome instrument provided data from the patient’s perspective yielding unique information as well as complementing clinician-rated CTCAE grades, especially for the symptoms of pain, pruritus, and paronychia. Conclusions Good to excellent psychometric properties for the FACT-EGFRI 18 were demonstrated, supporting further use of this patient-reported outcomes measure. Additional validation with a more diverse group of patients should be conducted