Predicting fatigue in older breast cancer patients receiving radiotherapy. A head-to-head comparison of established assessments.

Objectives: Because of substantial toxicities in older adults, chemotherapy is often omitted while the frequency of radiotherapy changes only minimally. In this study, we addressed the value of different assessments for predicting fatigue after radiotherapy in older breast cancer patients.

Patients And Methods: We included 74 women with primary breast cancer over the age of 65 years treated with radiotherapy (26 % with additional chemotherapy). Assessments were conducted before adjuvant treatment and after radiotherapy. The assessments included the Vulnerable Elders Survey (VES-13), the Karnofsky Performance Status (KPS), the EORTC Quality of Life assessment (EORTC-QLQ-C30), a cancer-specific comprehensive geriatric assessment (cancer-specific CGA), and the Fried frailty score. Multiple linear regression analyses were used to assess correlations with the FACIT-fatigue scale.

Results: Patients were on average 71 years old (range, 65-86 years). Most tumors (n=62) were classified as intermediate risk according to the St. Gallen consensus. The cancer-specific CGA was best associated with fatigue (p < 0.001, β estimate = 1.75), followed by the Fried frailty score (for the score of 1 versus reference of 2 and higher: p = 0.035, β estimate = - 5.74). There were no significant ceiling effects but there were substantial floor effects for the VES-13, KPS, and frailty score.

Conclusion: The cancer-specific CGA and the Fried frailty score (driven mainly by the item "exhaustion") outperformed the other indices in predicting fatigue in a group of rather well-functioning older women with primary breast cancer.