Specific types of anxiety regarding radiation therapy in patients with breast cancer: a longitudinal study

The radiotherapy categorical anxiety scale (RCAS) was designed to evaluate the specific types of radiation therapy (RT)-related anxiety in cancer patients. We translated RCAS into Chinese, evaluated its reliability and validity in breast cancer (BC) patients, and used it to evaluate changes in specific types and levels of RT-related anxiety throughout RT.

This was a prospective, longitudinal study enrolling 504 Chinese BC patients receiving RT. The patients completed questionnaires assessing the specific types of RT-related anxiety (our Chinese version of RCAS), depression [Patient Health Questionnaire-9 (PHQ-9)], and anxiety [Generalized Anxiety Disorder-7 (GAD-7)] before, during, and after RT. Emotional distress (ED) was defined as a PHQ-9 or GAD-7 score of > 4. Generalized estimating equation was performed to evaluate changes in total and subscale scores on RCAS. Multivariable general linear models were used to explore independent predictors of baseline RCAS scores.

Our Chinese version of RCAS demonstrated high internal consistency (Cronbach's α = 0.89-0.92). Our data demonstrated a Kaiser-Meyer-Olkin measure of 0.946 and P < 0.001 on the Bartlett sphericity test, indicating their suitability for subsequent confirmatory factor analysis (CFA). CFA further demonstrated its adequate convergent and discriminant validity. The levels of anxiety related to RT environment decreased over time, whereas those of anxiety related to RT treatment efficacy remained stable throughout the treatment. Patients demonstrated higher scores on items regarding side effects and treatment efficacy of RT than on other items. ED before RT independently predicted for higher baseline RCAS score.

Our Chinese version of the RCAS can be used to quantitatively evaluate specific types of RT-related anxiety in Chinese BC patients. Clinicians should pay more attention to anxiety regarding the side effects and treatment efficacy of RT reported by their patients, particularly those with baseline ED.