(Pre)treatment risk factors for late fatigue and fatigue trajectories following radiotherapy for breast cancer

Abstract

Fatigue is common in breast‐cancer survivors. Our study assessed fatigue longitudinally in breast cancer patients receiving adjuvant radiotherapy (RT) and aimed to identify risk factors associated with long‐term fatigue and underlying fatigue trajectories. Fatigue was measured in a prospective multicenter cohort (REQUITE) using the Multidimensional Fatigue Inventory (MFI‐20) and analyzed using mixed models. Multivariable logistic models identified factors associated with fatigue dimensions at 2 years post‐RT and latent class growth analysis identified individual fatigue trajectories. A total of 1443, 1302, 1203 and 1098 patients completed the MFI‐20 at baseline, end of RT, after 1 and 2 years. Overall, levels of fatigue significantly increased from baseline to end of RT for all fatigue dimensions (P < .05) and returned to baseline levels after 2 years. A quarter of patients were assigned to latent trajectory high (23.7%) and moderate (24.8%) fatigue classes, while 46.3% and 5.2% to the low and decreasing fatigue classes, respectively. Factors associated with multiple fatigue dimensions at 2 years include age, BMI, global health status, insomnia, pain, dyspnea and depression. Fatigue present at baseline was consistently associated with all five MFI‐20 fatigue dimensions (ORGeneralFatigue = 3.81, P < .001). From latent trajectory analysis, patients with a combination of factors such as pain, insomnia, depression, younger age and endocrine therapy had a particularly high risk of developing early and persistent high fatigue years after treatment. Our results confirmed the multidimensional nature of fatigue and will help clinicians identify breast cancer patients at higher risk of having persistent/late fatigue so that tailored interventions can be delivered.

Cancer‐related fatigue: Towards a more targeted approach based on classification by biomarkers and psychological factors

“…Three studies investigating fatigue trajectories indicated that having constantly high fatigue was associated with depression/ anxiety. [21][22][23] Thus, it appears reasonable that future studies examine this subgroup and investigate if the efficacy of fatigue treatment differs between cancer survivors with and without depression/anxiety. It would be of relevance for patients suffering from fatigue along with depressive symptoms if, for example, exercise or a psychological intervention would be more beneficial for them.…”