Abstract
Cancer-related cognitive impairment (CRCI) is a frequent side effect experienced by an increasing number of cancer survivors with a significant impact on their quality of life. Different definitions and means of evaluation have been used in available literature; hence the exact incidence of CRCI remains unknown. CRCI can be described as cognitive symptoms reported by cancer patients in self-reported questionnaires or as cognitive changes evaluated by formal neuropsychological tests. Nevertheless, association between cognitive symptoms and objectively assessed cognitive changes is relatively weak or absent. Studies have focused especially on breast cancer patients, but CRCI has been reported in multiple types of cancer, including colorectal, lung, ovarian, prostate, testicular cancer and hematological malignancies. While CRCI has been associated with various treatment modalities, including radiotherapy, chemotherapy, hormone therapy and novel systemic therapies, it has been also detected prior to cancer treatment. Therefore, the effects of cancer itself with or without the psychological distress may be involved in the pathogenesis of CRCI as a result of altered coping mechanisms after cancer diagnosis. The development of CRCI is probably multifactorial and the exact mechanisms are currently not completely understood. Possible risk factors include administered treatment, genetic predisposition, age and psychological factors such as anxiety, depression or fatigue. Multiple mechanisms are suggested to be responsible for CRCI, including direct neurotoxic injury of systemic treatment and radiation while other indirect contributing mechanisms are hypothesized. Chronic neuroinflammation mediated by active innate immune system, DNA-damage or endothelial dysfunction is hypothesized to be a central mechanism of CRCI pathogenesis. There is increasing evidence of potential plasma (e.g., damage associated molecular patterns, inflammatory components, circulating microRNAs, exosomes, short-chain fatty acids, and others), cerebrospinal fluid and radiological biomarkers of cognitive dysfunction in cancer patients. Discovery of biomarkers of cognitive impairment is crucial for early identification of cancer patients at increased risk for the development of CRCI or development of treatment strategies to lower the burden of CRCI on long-term quality of life. This review summarizes current literature on CRCI with a focus on long-term effects of different cancer treatments, possible risk factors, mechanisms and promising biomarkers.
Highlights
Considerable advances in clinical oncology over the past decades have resulted in significant improvement of long-term survival in cancer patients
This study showed that both chemotherapy and radiotherapy group performed worse in neuropsychological tests compared to healthy controls. (Shibayama et al, 2014, 2019) showed that breast cancer patients exposed to adjuvant regional radiotherapy might develop the cognitive impairment several months after the treatment
This study found increasing age was associated with decline in hippocampal volumes on magnetic resonance imaging (MRI) (p < 0.001), reduced levels of serum brain-derived neurotrophic factor (BDNF) and poorer memory performance
Summary
Considerable advances in clinical oncology over the past decades have resulted in significant improvement of long-term survival in cancer patients. Achieving the cure in cancer means that patients become survivors who may suffer from different types of late toxicities (Miller et al, 2019). Both patients and survivors often experience changes in cognition, called “cancer-related cognitive impairment” (CRCI), as a side effect of cancer and cancer treatment (Joly et al, 2015). The exact incidence and prevalence of CRCI is still unknown due to its various definitions in literature and different means of evaluation in studies. The prevalence estimates vary widely from 15 to 75% (Wefel et al, 2004; Vardy and Tannock, 2007; Janelsins et al, 2011; Schmidt et al, 2016; Lange et al, 2019b)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
