Assessing the risk of severe post-treatment (tx) cancer-related fatigue (CRF) among breast cancer survivors (BCS) in the CANcer TOxicity (CANTO) cohort.

Abstract

12022 Background: CRF is among the most common and troublesome symptoms experienced by BCS. While preventing severe post-tx CRF is a major survivorship need, limited tools exist to predict this risk. We aimed to describe the long-term prevalence rates and to identify BCS that are more likely to develop severe CRF. Methods: CANTO is a multicenter, prospective clinical study of stage I-III BCS (NCT01993498). Longitudinal data were collected at diagnosis (dx), 0.5 (T1), 1 (T2) and 3 (T3) years post-tx. The primary outcome of interest was severe post-tx global CRF (score ≥ 40/100, EORTC QLQ-C30). Secondary outcomes were physical, emotional and cognitive dimensions of CRF (QLQ-FA12). Multivariable logistic regression models retained associations with severe CRF by bootstrapped Augmented Backwards Elimination, validated using 10-fold internal cross-validation and overoptimism-corrected AUC. Results: Among 6619 BCS, mean age at dx was 56.5 years (SD 11.5), mean BMI was 25.9 Kg/m2 (SD 5.4), 53.3% and 80.8% received chemotherapy (CT) and hormonotherapy (HT), respectively. Prevalence rates of severe global CRF were 25.0% (dx), 35.6% (T1), 34.0% (T2) and 31.6% (T3). Severe post-tx global CRF was consistently associated with higher BMI, worse insomnia and pain, and severe pre-tx CRF. Receipt of CT increased odds of severe CRF at T1, whereas associations of HT with CRF emerged at T2 and T3 (Table). The estimated risk of severe CRF at T3 was 14% for a BCS with BMI 23.0 Kg/m2 and no concomitant symptoms at dx, whereas it was 82% for a BCS with BMI 32.0 Kg/m2, severe insomnia, pain and pre-tx CRF, receiving HT. Anxiety and depression at dx were consistently retained in models of severe post-tx emotional and cognitive CRF (all p <.05). Conclusions: Over 1/3 BCS endured persistent, severe global CRF, particularly those that were medically more fragile and reported heavier pre-tx symptom burden. A transient impact of CT on CRF was evident on the short aftermath of tx, whereas exposure to HT seemed to affect CRF on the longer run. Consistent factors flag BCS whose risk of severe CRF is high and who should be upfront targeted and aggressively helped. Dimension-specific risk factors can guide prevention of distinct CRF symptoms. Clinical trial information: NCT01993498. [Table: see text]