Association of Fatigue Intensification with Cognitive Impairment during Radiation Therapy for Prostate Cancer

Abstract

Purpose: Cancer-related fatigue is a common complaint during cancer treatment and is often associated with cognitive impairment. This study examined cognitive deficits that were associated with fatigue symptoms during external-beam radiation therapy (EBRT) in men with localized prostate cancer.

Methods: A total of 36 participants were enrolled and followed up at baseline, 24 h, 7 days, 14 days after EBRT initiation, at midpoint, and at completion of EBRT. Fatigue was measured by self-report using the Functional Assessment of Cancer Therapy - Fatigue (FACT-F), and cognitive impairment by the Computer Assessment of Mild Cognitive Impairment (CAMCI®).

Results: Subjects with increased fatigue during EBRT reported a significant decline in cognitive function and had difficulties with CAMCI®'s route finding and item recall tasks during EBRT. Increased fatigue during EBRT was associated with perceived cognitive difficulties in executive function and recognition memory, but not with attention or verbal memory.

Conclusions: Our results suggest that there might be specific cognitive domains that are associated with increased fatigue during EBRT. These findings will provide important information for targeting specific cognitive domains using pharmacotherapy or behavioral interventions. CAMCI® is a valuable tool for psycho social providers to detect subtle cognitive impairment in fatigued cancer patients in a clinical setting.

Keywords: Cancer-related fatigue; Cognitive impairment; Prostate cancer; Radiation therapy.

© 2018 S. Karger AG, Basel.

Figures

Fig. 1

Fatigue increased with external-beam radiation therapy (EBRT). a The FACT-F (Functional Assessment of Cancer Ther­apy – Fatigue) scores of the cohort (n = 36) decreased over time (baseline or prior to EBRT initiation, 1 day after EBRT, 1 week after EBRT, 2 weeks after EBRT, midpoint of EBRT, and com pletion of EBRT), reaching the lowest point at midpoint of EBRT. F(5, 294) = 3.69, p = 0.03. b Subjects were considered to have significantly increased fatigue (IF) when there was a decrease in FACT-F score of ≥3 points, whereas subjects with a FACT-F score change of < 3 points were considered to have stable fatigue (SF). There was no difference in fatigue between the IF (n = 20) and SF (n = 16) groups at baseline (p = 0.69). The IF subjects experienced significantly increased fatigue at the midpoint of EBRT compared to the SF subjects (d = 1.65, p = 6.08 × 10–7).

Fig. 2

Perception of cognitive capability was associated with fatigue during external-beam radiation therapy (EBRT). a Perceived cognitive impairment significantly increased in the IF (increased fatigue) subjects (n = 20) from baseline to the midpoint of EBRT (d = 1.28, p = 6.71 × 10–6). b Performance on the Stroop test under either the congruent or the incongruent condition was comparable between the IF (n = 20) and SF (stable fatigue) (n = 16) subjects (p > 0.05). rPFS, revised Piper Fatigue Scale.

Fig. 3

Memory impairment was associated with fatigue during external-beam radiation therapy (EBRT). a Screenshot of the virtual reality environment in CAMCI® (image credit: Psychology Software Tools, Inc.). b In the route finding task, the subject was provided with directions to the grocery store at the beginning of the shopping trip, and the directions remained on the screen throughout the shopping trip. The subject was asked to choose the direction to go at each intersection, and the y axis indicates percent accuracy. The IF (increased fatigue) subjects (n = 20) exhibited impaired executive function and decision-making in the route finding task compared to the SF (stable fatigue) subjects (n = 16) at the midpoint of EBRT (d = 0.86, p = 0.04). c In the item recall task, the subject was shown a list of items to purchase at the grocery store. At the end of the shopping trip, the subject was asked to select images of the items that needed to be purchased. The IF subjects (n = 20) exhibited impaired functional memory accuracy compared to the SF subjects (n = 16) at the midpoint of EBRT (d = 1.07, p = 0.02). d In the word recognition task, the subjects were instructed to select words they had previously encountered in the learning phase. Fatigue significantly correlated with speed (r = 0.46, p = 0.009) but not accuracy in the word recognition task. FACT-F, Functional Assessment of Cancer Therapy – Fatigue.

Fig. 4

Longitudinal learning effect of various CAMCI® tasks. Performance on each CAMCI® task is shown as the percentage of correct answers. Each line indicates the average score on each CAMCI® task for all subjects. Overall, the subjects improved on the majority of the CAMCI® tasks over the three time points tested (baseline, midpoint of EBRT, and EBRT completion). F(2, 22) = 8.13, p = 0.002.