Longitudinal association between cancer-related fatigue and physical function in cancer patients undergoing concurrent chemoradiotherapy: a retrospective cohort study

Background The longitudinal relationship between cancer-related fatigue (CRF) and physical function remains unclear. This study evaluated the association between pre-treatment physical functions and CRF exacerbation following concurrent chemoradiotherapy (CCRT). Methods The study included 42 cancer patients undergoing CCRT. Poor physical function was de ned as the presence of either or both low grip strength (<26 kg, <18 kg) and slow walking speed (<1.0 m/s) at the start of CCRT. CRF was assessed using the Japanese version of the Functional Assessment of Chronic Illness Therapy-Fatigue Scale at the start of CCRT and 6 weeks later. Patients were categorized into the CRF exacerbation group if their scores decreased by >3 points. A multivariate logistic regression analysis was performed to identify the association between poor physical function and exacerbation of CRF. Results Seventeen (40.5%) patients developed CRF exacerbation following CCRT. More patients had poor physical function in the CRF exacerbation group (58.8% vs. 20.0%; p=0.02). Poor physical function was an independent risk factor for exacerbation of CRF following CCRT after adjusting for confounders. Conclusions Poor physical function was a risk factor for exacerbation of CRF following CCRT. Assessing physical function may be useful in determining patients at high risk for CRF exacerbation following CCRT.