Breast cancer (BC) related fatigue: A longitudinal investigation of its prevalence, domains and correlates

Abstract

Background: Fatigue is a complex and multidimensional symptom that is recognized as one of the most distressing and potentially long lasting side effects of cancer treatment (trt). Large scale data that help predict and prevent severe fatigue are lacking. Methods: We carried out a detailed longitudinal analysis of fatigue using a large ongoing national prospective clinical study (CANTO, NCT01993498) of stage I-III BC patients (pts) treated from 2012-14. Pts answered fatigue questionnaires at diagnosis (dx), 3-6 (T1) and 12 months (T2) post trt. Severe fatigue was defined by EORTC QLQ C30 scores ≥40 for overall fatigue and EORTC F12 ≥50 for physical, emotional and cognitive domains of fatigue (Giesinger, 2016). We used group based trajectory models to identify clusters of pts with high risk of severe fatigue and associated factors. Results: We analyzed 4160 pts with 1 year follow up data available, 30% were age<50, 16% were smokers, 53% received chemo- (CT), 91% radio- and 82% endocrine trt. Overall severe fatigue was reported by 23% pts at dx, increasing to 34% by T2 (p <0.001), comorbidities (p=0.014), smoking (p=0.008), HR+ BC (p=0.025) and use of CT (p=0.008). An interaction between severe fatigue and multiple physical and psychological symptoms was found in this subgroup (p<0.001). We also observed differential patterns of change in prevalence of fatigue from dx to T2 by fatigue domain: from 13 to 20% for physical, 18 to 14% for emotional and 12 to 13% for cognitive fatigue (all p