Examining the effects of adjuvant chemotherapy on cognition and the impact of any cognitive impairment on quality of life in colorectal cancer patients: study protocol

Background: Research suggests that chemotherapy can cause deficits in both patients’ objectively measured and self-reported cognitive abilities which can in turn affect their quality of life (QoL). The majority of research studies have used post-treatment retrospective designs or have not included a control group in prospective cohorts. This has limited the conclusions that can be drawn from the results. There have also been a disproportionate number of studies focussed on women with breast cancer, which has limited the generalisability of the results to other cancer populations. Aim: This study aims to identify the extent and impact of chemotherapy-induced cognitive decline in colorectal cancer patients. Possible associations with poorer QoL will also be explored. Design: This will be a longitudinal controlled cohort study. Questionnaires measuring subjective cognitive functioning, QoL, fatigue and mood, and neuropsychological assessments of objective cognitive function will be collected pre-, mid- and post- chemotherapy treatment from a consecutive sample of 78 colorectal cancer patients from five London NHS Trusts. A further 78 colorectal cancer surgery only patients will be assessed at equivalent time points; this will allow the researchers to compare the results of patients undergoing surgery, but not chemotherapy against those receiving both treatments. Pre- and post-chemotherapy difference scores will be calculated to detect subtle changes in cognitive function as measured by the objective neuropsychological assessments and the self-reported questionnaires. A standardised zscore will be computed for every patient on each neuropsychological test, and for each test at each time point. The post-chemotherapy score will then be subtracted from the pre-chemotherapy score to produce a relative difference score for each patient. ANCOVA will be used to compare mean difference z-scores between the chemotherapy and surgery-only groups while controlling for the effects of gender, age, depression, anxiety, fatigue and education. Discussion: The result from this study will indicate whether a decline in cognitive functioning can be attributed to chemotherapy or to disease, surgical or some other confounding factor. Identification of risk factors for cognitive deficits may be used to inform targeted interventions, in order to improve QoL and help patients’ cope

Fluoxetine reverses the memory impairment and reduction in proliferation and survival of hippocampal cells caused by methotrexate chemotherapy

RATIONALE: Adjuvant cancer chemotherapy can cause long-lasting, cognitive deficits. It is postulated that these impairments are due to these drugs targeting neural precursors within the adult hippocampus, the loss of which has been associated with memory impairment. OBJECTIVES: The present study investigates the effects of the chemotherapy, methotrexate (MTX) on spatial working memory and the proliferation and survival of the neural precursors involved in hippocampal neurogenesis, and the possible neuroprotective properties of the antidepressant fluoxetine. METHODS: Male Lister hooded rats were administered MTX (75 mg/kg, two i.v. doses a week apart) followed by leucovorin rescue (i.p. 18 h after MTX at 6 mg/kg and at 26, 42 and 50 h at 3 mg/kg) and/or fluoxetine (10 mg/kg/day in drinking water for 40 days). Memory was tested using the novel location recognition (NLR) test. Using markers, cell proliferation (Ki67) and survival (bromodeoxyuridine/BrdU), in the dentate gyrus were quantified. RESULTS: MTX-treated rats showed a cognitive deficit in the NLR task compared with the vehicle and fluoxetine-treated groups. Cognitive ability was restored in the group receiving both MTX and fluoxetine. MTX reduced both the number of proliferating cells in the SGZ and their survival. This was prevented by the co-administration of fluoxetine, which alone increased cell numbers. CONCLUSIONS: These results demonstrate that MTX induces an impairment in spatial working memory and has a negative long-term effect on hippocampal neurogenesis, which is counteracted by the co-administration of fluoxetine. If translatable to patients, this finding has the potential to prevent the chemotherapy-induced cognitive deficits experienced by many cancer survivors

Gene expression signatures for colorectal cancer microsatellite status and HNPCC

The majority of microsatellite instable (MSI) colorectal cancers are sporadic, but a subset belongs to the syndrome hereditary nonpolyposis colorectal cancer (HNPCC). Microsatellite instability is caused by dysfunction of the mismatch repair (MMR) system that leads to a mutator phenotype, and MSI is correlated to prognosis and response to chemotherapy. Gene expression signatures as predictive markers are being developed for many cancers, and the identification of a signature for MMR deficiency would be of interest both clinically and biologically. To address this issue, we profiled the gene expression of 101 stage II and III colorectal cancers (34 MSI, 67 microsatellite stable (MSS)) using high-density oligonucleotide microarrays. From these data, we constructed a nine-gene signature capable of separating the mismatch repair proficient and deficient tumours. Subsequently, we demonstrated the robustness of the signature by transferring it to a real-time RT-PCR platform. Using this platform, the signature was validated on an independent test set consisting of 47 tumours (10 MSI, 37 MSS), of which 45 were correctly classified. In a second step, we constructed a signature capable of separating MMR-deficient tumours into sporadic MSI and HNPCC cases, and validated this by a mathematical cross-validation approach. The demonstration that this two-step classification approach can identify MSI as well as HNPCC cases merits further gene expression studies to identify prognostic signatures

Can physical activity help to maintain cognitive functioning and psychosocial well-being among breast cancer patients treated with chemotherapy? A randomised controlled trial: study protocol

Background: Evidence suggests chemotherapy treatment for breast cancer is associated with side effects such as cognitive impairment in domains of memory, attention, concentration and executive function. Cognitive impairments reported by patients have been associated with higher levels of emotional distress. To date, intervention studies to alleviate cognitive impairment associated with chemotherapy have focused on psycho-educational techniques or cognitive training. Studies have not yet considered physical activity as a potential for alleviating cognitive problems. Physical activity interventions are reported to be effective in alleviating emotional distress and fatigue in those with breast cancer. They have also been reported to improve cognitive functioning in the elderly, in those suffering with dementia and in children. We propose that physical activity could also help to alleviate cognitive impairments in women diagnosed with breast cancer. The study has been designed using a recently developed taxonomy of behaviour change techniques to reliably report the content of the intervention to allow future replication. Method: This study will deliver a home-based moderate intensity walking intervention to women diagnosed with breast cancer mid-way through their chemotherapy treatment and will compare them to patients receiving usual care alone. The primary outcome measure for this intervention is changes in an objective measure of memory assessed using the Digit Span. Secondary outcome measures include: objective measures of executive function; attention; visual spatial skills; self report cognitive function; self-report fatigue; anxiety; depression; mood and self-esteem. As emotional distress has been associated with self-reporting of cognitive problems, this intervention will further test whether emotional distress mediates between the amount of walking undertaken during the intervention period and levels of self-reported cognitive functioning. Discussion: The development of an effective intervention for preventing difficulties in emotional and cognitive functioning of cancer patients’ post-treatment will help to guide health care professionals to improve patients’ overall quality of life. It will also provide direction for future research, ultimately to improve the day to day functioning of breast cancer survivors. Trial Registration: Current Controlled Trials ISRCTN50709297. Keywords: Intervention, Breast cancer, Chemotherapy, Physical activity, Exercise, Walking, Cognitive function, Emotional distress, Psychosocial well-bein

Overcoming Endocrine Resistance in Hormone Receptor–Positive Breast Cancer

Endocrine therapy, a major modality in the treatment of hormone receptor (HR)–positive breast cancer (BCA), has improved outcomes in metastatic and nonmetastatic disease. However, a limiting factor to the use of endocrine therapy in BCA is resistance resulting from the development of escape pathways that promote the survival of cancer cells despite estrogen receptor (er)–targeted therapy. The resistance pathways involve extensive cross-talk between ER and receptor tyrosine kinase growth factors [epidermal growth factor receptor, human epidermal growth factor receptor 2 (HER2), and insulin-like growth factor 1 receptor] and their downstream signalling pathways—most notably pi3k/akt/mtor and mapk. In some cases, resistance develops as a result of genetic or epigenetic alterations in various components of the signalling pathways, such as overexpression of HER2 and ERα co-activators, aberrant expression of cell-cycle regulators, and PIK3CA mutations. By combining endocrine therapy with various molecularly targeted agents and signal transduction inhibitors, some success has been achieved in overcoming and modulating endocrine resistance in HR-positive BCA. Established strategies include selective ER downregulators, anti-HER2 agents, mtor (mechanistic target of rapamycin) inhibitors, and inhibitors of cyclin-dependent kinases 4 and 6. Inhibitors of pi3ka are not currently a treatment option for women with HR-positive BCA outside the context of clinical trial. Ongoing clinical trials are exploring more agents that could be combined with endocrine therapy, and biomarkers that would help to guide decision-making and maximize clinical efficacy. In this review article, we address current treatment strategies for endocrine resistance, and we highlight future therapeutic targets in the endocrine pathway of BCA

Real-World Use of Trifluridine/Tipiracil for Patients with Metastatic Colorectal Cancer in Canada

Background: Outcomes for patients with metastatic colorectal cancer (MCRC) are improving with the introduction of new treatments. Treatment for patients who are still fit after failure of all available therapies represents a significant unmet need. In the present study, we analyzed real-world treatment patterns for patients enrolled in Health Canada’s trifluridine/tipiracil (FTD/TPI) Special Access Program (SAP) and Taiho Pharma Canada’s Patient Support Program (PSP). Methods: Demographic information and clinical treatment data were collected from adults with mcrc who were previously treated with, or were not candidates for, available therapies and who were enrolled in the SAP and PSP. For all patients, FTD/TPI treatment status, discontinuation reasons, and prior therapies were examined. Results: The analysis included 717 Canadian patients enrolled in the FTD/TPI sap and PSP from September 2017 to October 2018. In that cohort, 59.7% were men, median age was 65 years, and median duration of therapy was 77 days (25%–75% interquartile range: 43–106 days). Of treated patients, 67.1% maintained the same dose for the duration of therapy; 28.0% had a dose reduction. On multivariable analysis, duration of therapy was not influenced by sex, age, province, RAS mutation status, or prior therapies. However, prior oxaliplatin-based chemotherapy (CAPOX or FOLFOX) appeared to be associated with higher rates of discontinuation because of death or disease progression. Conclusions: In advanced MCRC, FTD/TPI is a well-tolerated therapy. The large number of patients enrolled in the access programs within a short period of time is reflective of major clinical need in this area, with many patients being eligible and interested in pursuing treatment in the refractory setting