Factors associated with fatigue in prostate cancer (PC) patients undergoing external beam radiation therapy (EBRT)

Fatigue is a common adverse effect among cancer patients undergoing external beam radiation therapy (EBRT), yet the underlying disease- and treatment-related factors influencing its development are poorly understood. We hypothesized that clinical, demographic, and treatment-related factors differentially affect fatigue and aimed to better characterize variables related to fatigue development in prostate cancer (PC) patients during EBRT.

We identified a cohort of 681 patients with nonmetastatic PC undergoing a 6- to 9-week EBRT course. Patient fatigue scores (range, 0-3) were prospectively recorded by providers during treatment visits using standardized criteria. Clinical and demographic factors including age, race, EBRT details, disease staging, smoking status, comorbidities, urinary symptoms, employment status, weight, and concurrent medication use were assessed for their relationship to fatigue levels. Significant differences in fatigue severity by each variable at the beginning and end of EBRT were assessed by nonparametric means testing, and differences in the level of fatigue increase over the treatment course were assessed using an ordered logistic regression model.

Significant increases in reported fatigue severity were seen in patients with age <60 years (P = .006), depressive symptoms (P < .001), and use of androgen deprivation therapy before radiation start (P = .04). In addition, the prescription of antiemetics before radiation start was associated with reduced fatigue severity (P = .03).

We identify factors associated with increased (young age, depressive symptoms, androgen deprivation therapy) and decreased (antiemetic prescription) fatigue in a large cohort of PC patients receiving EBRT. Continued investigation is needed to further elucidate clinical drivers and biological underpinnings of increased fatigue to guide potential interventions.