Cognitive and neurobehavioral symptoms in patients with non-metastatic prostate cancer treated with androgen deprivation therapy or observation: A mixed methods study

BACKGROUND: Few studies have investigated prostate cancer patients' experiences of cognitive functioning or neurobehavioral symptoms (i.e., behavioral changes associated with neurological dysfunction) following androgen deprivation therapy (ADT). METHODS: Semi-structured interviews conducted from the US by phone and in-person were used to explore and characterize the: 1) experience of cognitive and neurobehavioral functioning in non-metastatic prostate cancer patients undergoing ADT (n = 19) compared with patients who had not undergone ADT (n = 20); 2) perceived causes of cognitive and neurobehavioral symptoms; 3) impact of these symptoms on quality of life; and 4) strategies used to cope with or compensate for these symptoms. Neuropsychological performance was assessed to characterize the sample. RESULTS: Overall, ADT patients experienced marginally more cognitive problems than non-ADT (nADT) patients even though there were no significant differences between groups in neuropsychological performance. ADT patients also experienced more declines in prospective memory and multi-tasking than nADT patients. Significant proportions of participants in both groups also experienced retrospective memory, attention and concentration, and information processing difficulties. With respect to neurobehavioral symptoms, more ADT patients experienced emotional lability and impulsivity (both aspects of disinhibition) than nADT patients. Among the causes to which participants attributed declines, both groups attributed them primarily to aging. A majority of ADT patients also attributed declines to ADT. For both groups, increased cognitive and neurobehavioral symptoms negatively impacted quality of life, and most participants developed strategies to ameliorate these problems. CONCLUSION: ADT patients are more vulnerable to experiencing specific cognitive and neurobehavioral symptoms than nADT patients. This study highlights the importance of capturing: a) cognitive symptoms not easily detected using neuropsychological tests; b) neurobehavioral symptoms that can be confused with psychological symptoms, and c) causal beliefs that may affect how people cope with these symptoms. Effective interventions are needed to assist prostate cancer patients in managing these symptoms.