Chemotherapy and Post-traumatic Stress in the Causation of Cognitive Dysfunction in Breast Cancer Patients

THE CREATIVE PSYCHOSOCIAL GENOMIC HEALING EXPERIENCE (CPGHE) AND GENE EXPRESSION IN BREAST CANCER PATIENTS: A FEASIBILITY STUDY

BACKGROUND

Biomarkers associated with inflammation and immune function are increasingly being used to examine mechanisms of the effects of mind-body therapies. Less researched are biomarkers associated with cognitive and executive functioning in the study of mind-body therapy mechanisms and effects. This study explored the feasibility of recruiting breast cancer patients (BCPs) and implementation fidelity of participation in a research project utilizing the 4-stage Creative Psychosocial Genomic Healing Experience (CPGHE), a mind-body protocol that is theorized to create epigenetic effects via targeted psychological change in emotional triggers in coping with cancer.

METHODS

Eight BCPs were identified as eligible (stages I, II, III, early phases of treatment) and five consented to one of two intervention groups (allocated to a single session or two sessions of CPGHE). Blood draws were examined pre- and post- intervention for a stress/inflammation gene expression marker, Nuclear Factor kappa-B (NF-kB), and three markers associated with synaptic plasticity undergirding cognitive and executive functioning: Early Growth Response 1 (EGR1), activity-regulated cytoskeleton-associated protein (Arc), and brain-derived neurotrophic factor (BDNF).

RESULTS

One consented BCP dropped out due to illness. The remaining four adhered to the 4-stage CPGHE protocol and found the CPGHE experience beneficial. Blood samples for the gene expression results were collected and processed according to planned protocol without incident.

CONCLUSION

Implementing the CPGHE and achieving good adherence among a sample of BCPs is feasible. Processing of blood samples collected from BCPs for gene expression data is also feasible.

Effects of Cyclophosphamide and/or Doxorubicin in a Murine Model of Postchemotherapy Cognitive Impairment

Postchemotherapy cognitive impairment, or PCCI, is a common complaint, particularly among breast cancer patients. However, the exact nature of PCCI appears complex. To model the human condition, ovariectomized C57BL/6J mice were treated intravenous weekly for 4 weeks with saline, 2 mg/kg doxorubicin (DOX), 50 mg/kg cyclophosphamide (CYP), or DOX + CYP. For the subsequent 10 weeks, mice were assessed on several behavioral tests, including those measuring spatial learning and memory. After sacrifice, hippocampal spine density and morphology in the dentate gyrus, CA1, and CA3 regions were measured. Additionally, hippocampal levels of total glutathione, glutathione disulfide, MnSOD, CuZnSOD, and cytokines were measured. Body weight decreased in all groups during treatment, but recovered post-treatment. Most behaviors were unaffected by drug treatment: Open field activity, motor coordination, grip strength, water maze and Barnes maze performance, buried food test performance, and novel object and object location recognition tests. There were some significant effects of CYP and DOX + CYP treatment during the initial test of home cage behavior, but these did not persist into the second and third test times. Density of stubby spines, but not mushroom or thin spines, in the dentate gyrus was significantly decreased in the DOX, CYP, and DOX + CYP treatment groups. There were no significant effects in the CA1 or CA3 regions. CuZnSOD levels were significantly increased in DOX + CYP-treated mice; other hippocampal antioxidant levels were unaffected. Most cytokines showed no treatment-related effects, but IL-1β, IL-6, and IL-12 were slightly reduced in mice treated with DOX + CYP. Although the animal model, route of exposure, and DOX and CYP doses used here were reflective of human exposure, there were only sporadic effects due to chemotherapeutic treatment.

Cancer-Related Cognitive Impairment in Breast Cancer Patients: Influences of Psychological Variables

Approximately 3.1 million women in the US are living with breast cancer and up to 75% of these women experience cancer-related cognitive impairment (CRCI). CRCI is described as impairments in memory, verbal fluency, thought processes, and attention span. Despite the high prevalence of breast cancer, only a few studies have been published on CRCI and most of these studies primarily focused on its pathophysiological mechanism. However, recent evidence has demonstrated that breast cancer patients with CRCI are more likely to have high level of psychologic distress, suggesting a possible relationship between CRCI and psychologic distress. This review aims to examine existing literature that describes CRCI in relation to psychological distress among breast cancer patients. One thousand four hundred and ninety-eight articles were searched using PubMed, CINAHL, and PsycINFO. Thirteen studies met inclusion criteria, and one article was additionally pulled from article reference lists. Of these19 studies, psychologic distress has been operationalized in varied ways such as anxiety (n = 3), depression (n = 2), both anxiety and depression (n = 4), stress (n = 4), worry (n = 2), mental fatigue (n = 1), and undefined psychological distress (n = 2). Except for six studies designed as a longitudinal study, the rest of studies used a cross-sectional design. Twelve studies used both subjective and objective measures to assess cognitive function. We found that the patients with high psychological distress displayed lower performance on cognitive function tests. Our finding indicates that psychological variables contributed to CRCI that breast cancer patients experienced. Areas for further investigation are proposed that will advance the care of breast cancer patients with CRCI.