Association of mitochondrial DNA content and displacement loop region sequence variations with cancer-related fatigue in breast cancer survivors receiving chemotherapy.

Cancer-related fatigue (CRF) is characterized by a lack of energy, and mitochondrial dysfunction is postulated to contribute to its etiology. This prospective cohort study assesses the self-reported fatigue levels of early-stage breast cancer patients using the validated Multi-Dimensional Fatigue Symptom Inventory-Short Form (MFSI-SF) and blood samples drawn at three time points: before treatment, approximately 6 weeks, and 12 weeks after the initiation of chemotherapy. The aim of this study is to evaluate mitochondrial measures with CRF, over the course of chemotherapy using mitochondrial DNA (mtDNA content) and displacement loop (D-loop) region sequence variations at nucleotide positions 303, 489 and 514. The relative mtDNA copy number was determined via real-time quantitative polymerase chain reaction and compared between study time points and D-loop sequence variants. The association of mtDNA content with MFSI-SF total and sub-domain scores was analyzed in a sample of 155 patients (mean age ± SD: 51.7 ± 8.8 years). The median mtDNA content decreased over 12 weeks after the initiation of chemotherapy (p < 0.001). Baseline mtDNA content was lower for nucleotide position 303 in sequence variations than for the reference sequence (67.2 copies vs 79.1 copies, p = 0.03). Physical fatigue negatively correlated with mtDNA content in both unadjusted (ß = -0.0075, p = 0.048) and adjusted models (ß = -0.0062, p = 0.042), accounting for age, anxiety, insomnia, haemoglobin levels and body mass index. Our findings add to the literature indicating that mitochondrial function serves as an important target for mitigating CRF.

HPLC-MS/MS coupled with equilibrium dialysis method for quantification of free drug concentration of pazopanib in plasma.

BACKGROUND: The selective occurrence of hepatotoxicity observed with use of pazopanib may be attributed to its high level of plasma protein binding and low hepatic extraction ratio. The primary objective was to investigate changes in free drug concentration amongst patients with varying albumin concentrations. METHODS: A HPLC-MS/MS method using C18 column (4.6 × 150 mm, 5 µm) with ESI source in positive mode had been developed and validated for the quantitative determination of free pazaopanib concentration in human plasma. Prior to sample preparation, patient samples were subjected to 6-hour equilibrium dialysis with molecular weight cut-off set at 8000 Da. RESULTS: The calibration curves were linear over the range of 5-1000 ng/mL, with a lower limit of quantification of 5 ng/mL. The intra-day and inter-day precisions and accuracies were all within ± 15 %, at 3 different quality controls. Higher median fraction unbound of pazopanib were observed in patients (n = 17) with lower than normal albumin concentrations. CONCLUSION: With the developed assay, monitoring of plasma free concentrations may be evaluated as an indicator of pazopanib exposure in patients.

An Evaluation of DNA Methyltransferase 1 (DNMT1) Single Nucleotide Polymorphisms and Chemotherapy-Associated Cognitive Impairment: A Prospective, Longitudinal Study.

Strong evidence suggests that genetic variations in DNA methyltransferases (DNMTs) may alter the downstream expression and DNA methylation patterns of neuronal genes and influence cognition. This study investigates the association between a DNMT1 polymorphism, rs2162560, and chemotherapy-associated cognitive impairment (CACI) in a cohort of breast cancer patients. This is a prospective, longitudinal cohort study. From 2011 to 2017, 351 early-stage breast cancer patients receiving chemotherapy were assessed at baseline, the midpoint, and the end of chemotherapy. DNA was extracted from whole blood, and genotyping was performed using Sanger sequencing. Patients' self-perceived cognitive function and cognitive performance were assessed at three different time points using FACT-Cog (v.3) and a neuropsychological battery, respectively. The association between DNMT1 rs2162560 and cognitive function was evaluated using logistic regression analyses. Overall, 33.3% of the patients reported impairment relative to baseline in one or more cognitive domains. Cognitive impairment was observed in various objective cognitive domains, with incidences ranging from 7.2% to 36.9%. The DNMT1 rs2162560 A allele was observed in 21.8% of patients and this was associated with lower odds of self-reported cognitive decline in the concentration (OR = 0.45, 95% CI: 0.25-0.82, P = 0.01) and functional interference (OR = 0.48, 95% CI: 0.24-0.95, P = 0.03) domains. No significant association was observed between DNMT1 rs2162560 and objective cognitive impairment. This is the first study to show a significant association between the DNMT1 rs2162560 polymorphism and CACI. Our data suggest that epigenetic processes could contribute to CACI, and further studies are needed to validate these findings.

Association of plasma leptin, pro-inflammatory adipokines and cancer-related fatigue in early-stage breast cancer patients: A prospective cohort study.

Cancer-related fatigue (CRF) is subjective and has wide inter-individual variability. Given that leptin is commonly associated with fatigue syndrome, its use as a potential biomarker for CRF is being investigated. The primary objective of this study was to evaluate the association between leptin and CRF in early-stage breast cancer patients receiving chemotherapy. In a prospective cohort study, patients completed assessments at baseline (T1), during chemotherapy (T2) and after chemotherapy (T3). Levels of plasma leptin and adipokines were measured using a Luminex bead-immunoassay and CRF was measured using the Multi-Dimensional Fatigue Symptom Inventory-Short Form (MFSI-SF). Data were analysed longitudinally using a generalised estimating equation incorporating clinically relevant parameters and pro-inflammatory adipokines. The analysis included 136 patients (mean age ± SD = 51.5 ± 8.8 years; 69.1% receiving anthracycline-based chemotherapy). More patients experienced CRF at T3 (23.8%) than at T2 (13.8%) compared to baseline. An increase was observed in the median plasma leptin level at T2, followed by a decrease at T3 (T1: 4.07 ng/mL, T2: 4.95 ng/mL and T3: 3.96 ng/mL). In the multivariate model, the change in leptin levels over time was significantly associated with the total MFSI-SF score (ß = -0.15, P = 0.003) after adjusting for the tumour necrosis factor-α (TNF-α) level, anxiety, depression, insomnia, age, menopausal status and type of chemotherapy. This is the first study to report leptin as a biomarker that predicts the onset of CRF over time. Future studies are required to validate the findings.

Prechemotherapy Levels of Plasma Dehydroepiandrosterone and Its Sulfated Form as Predictors of Cancer-Related Cognitive Impairment in Patients with Breast Cancer Receiving Chemotherapy.

STUDY OBJECTIVE: Dehydroepiandrosterone (DHEA) and its sulfated form (DHEAS)-jointly referred to as DHEA(S)-are neurosteroids known to regulate brain development and function that have been found to be positively correlated with cognitive function. It is unknown whether prechemotherapy plasma DHEA(S) levels are associated with the onset of cancer-related cognitive impairment (CRCI). The objective of this study was to evaluate whether an association exists between prechemotherapy plasma DHEA(S) levels and onset of CRCI in patients with breast cancer receiving chemotherapy. DESIGN: Multicenter, prospective cohort study. SETTING: Two specialized cancer centers in Singapore. PATIENTS: Eighty-one patients with early-stage breast cancer (stages I-III) who had no prior exposure to chemotherapy and/or radiotherapy and were scheduled to receive anthracycline-based or taxane-based chemotherapy treatment with curative intent. MEASUREMENTS AND MAIN RESULTS: Patients completed assessments for self-perceived and objective cognitive function at three time points: prechemotherapy (T1), during chemotherapy (T2), and after chemotherapy (T3). Plasma samples were collected prior to chemotherapy, and DHEA(S) levels were quantified by using ultra-high-performance liquid chromatography-tandem mass spectrometry. Multivariable logistic regression was used to adjust for clinically important factors and to evaluate the association between prechemotherapy plasma DHEA(S) levels and CRCI. Mean ± SD age was 48.9 ± 9.3 years, with 27.8% of patients experiencing clinically significant cognitive impairment based on global Functional Assessment of Cancer Therapy-Cognitive Function scores. The mean ± SD prechemotherapy plasma DHEAS and DHEA levels were 1.61 ± 0.91 µmol/L and 19.21 ± 13.13 nmol/L, respectively. Prechemotherapy DHEAS levels were found to be associated with impairment in the self-perceived cognitive domains of verbal fluency (adjusted odds ratio [OR] 0.27, 95% confidence interval [CI] 0.08-0.96) and mental acuity (adjusted OR 0.25, 95% CI 0.08-0.74). Conversely, DHEA levels were not associated with impairment in any cognitive subdomains. CONCLUSION: Our findings suggest that patients with higher prechemotherapy DHEAS levels had lower odds of developing self-perceived cognitive impairment. Future studies are required to further investigate the effect of DHEA(S) on specific cognitive domains and to validate our findings in independent cohorts.

Replication and Meta-analysis of the Association between BDNF Val66Met Polymorphism and Cognitive Impairment in Patients Receiving Chemotherapy.

Cancer-related cognitive impairment (CRCI) adversely affects cancer patients. We had previously demonstrated that the BDNF Val66Met genetic polymorphism is associated with lower odds of subjective CRCI in the multitasking and verbal ability domains among breast cancer patients receiving chemotherapy. To further assess our previous findings, we evaluated the association of BDNF Val66Met polymorphism with subjective and objective CRCI in a temporally separate cohort of patients and pooled findings from both the original (n = 145) and current (n = 193) cohorts in a meta-analysis. Subjective CRCI was assessed using FACT-Cog. Objective CRCI was evaluated using computerized neuropsychological tests. Genotyping was carried out using Sanger sequencing. The association of BDNF Val66Met genotypes and CRCI was examined with logistic regression. A fixed-effect meta-analysis was conducted using the inverse variance method. In the meta-analysis (n = 338), significantly lower odds of CRCI were associated with Met allele carriers based on the global FACT-Cog score (OR = 0.52, 95% CI 0.29-0.94). Furthermore, Met allele carriers were at lower odds of developing impairment in the domains of memory (OR = 0.34, 95% CI: 0.17-0.70), multitasking (OR = 0.33, 95% CI: 0.18-0.59), and verbal ability (OR = 0.46, 95% CI: 0.24-0.88). Consistent with the previous study, lower odds of subjective CRCI among patients with the BDNF Met allele was observed after adjusting for potential confounders in the multitasking (OR = 0.30, 95% CI: 0.14-0.67) domain. In conclusion, carriers of the BDNF Met allele were protected against global subjective CRCI, particularly in the domains of memory, multitasking, and verbal ability. Our findings further contribute to the understanding of CRCI pathophysiology.

Impact of Adjuvant Anthracycline-Based and Taxane-Based Chemotherapy on Plasma VEGF Levels and Cognitive Function in Breast Cancer Patients: A Longitudinal Study.

BACKGROUND: Vascular endothelial growth factor (VEGF) has been shown to induce neurogenesis in the brain and yield neuroprotective effects. It is hypothesized that chemotherapy reduces circulating VEGF levels and leads to cognitive decline among patients. This multicenter longitudinal study aimed to evaluate the impact of chemotherapy on VEGF levels and the association between VEGF levels and cognitive function. PATIENTS AND METHODS: A total of 145 early-stage breast cancer patients were recruited and assessed before chemotherapy (T1), during chemotherapy (T2), and at the end of chemotherapy (T3). At each time point, plasma VEGF levels were assessed using a multiplex immunoassay. Cognitive function was assessed using both Functional Assessment of Cancer Therapy-Cognitive Function, Version 3 (FACT-Cog), and Headminder (a computerized, web-based neuropsychologic battery). RESULTS: Generally, we observed higher-than-baseline plasma VEGF levels after the start of chemotherapy (P < .001). Among patients receiving anthracycline-based chemotherapy, the median plasma VEGF levels were significantly higher at T2 (T2: 37.3 pg/mL vs. T1: 21.3 pg/mL; P < .001) and T3 (T3: 35.5 pg/mL vs. T1: 21.3 pg/mL; P < .001) than at baseline. Plasma VEGF levels were not associated with chemotherapy-associated cognitive impairment. CONCLUSION: Breast cancer patients experience an increasing trend in plasma VEGF levels during chemotherapy, and the regimen types may have a differential effect on circulating VEGF levels. Furthermore, changes in plasma VEGF levels during chemotherapy were not associated with cognitive impairment. VEGF may play a minor role in mediating the occurrence of chemotherapy-associated cognitive impairment.

Distinct and heterogeneous trajectories of self-perceived cognitive impairment among Asian breast cancer survivors.

OBJECTIVES: Currently, there are no studies that have established the self-perceived cognitive trajectories experienced by breast cancer patients (BCPs) post-chemotherapy. Therefore, we characterized the long-term trajectory of self-perceived cognitive function among Asian early-stage BCPs using the minimal clinically important difference of a subjective measure of cognitive function. METHODS: Early-stage BCPs who received chemotherapy were recruited and assessed at 4 time points: Before chemotherapy initiation (T1), 6 weeks post-chemotherapy initiation (T2), 12 weeks post-chemotherapy initiation (T3), and 15-months post-chemotherapy initiation (T4). All assessments were performed approximately within 2 weeks post-chemotherapy. Subjective and objective cognitive function were assessed using Functional Assessment of Cancer Therapy-Cognitive (version 3) and Headminder™. RESULTS: A total of 166 BCPs were recruited, of whom 131 completed assessment at all time points. Using the minimal clinically important difference of Functional Assessment of Cancer Therapy-Cognitive, 5 distinct cognitive trajectories were established. Of the 131 patients, 70 (53.4%) did not report any clinically significant cognitive impairment. Twenty-one (16.0%) patients reported acute cognitive changes during chemotherapy (T2 and/or T3) but not at T4. Forty patients (30.5%) reported clinically significant cognitive impairment at T4, of whom 18 did not report any cognitive impairment at earlier time points. Fifteen (11.5%) patients reported persistent cognitive impairment throughout all time points, while 7 (5.3%) patients reported intermittent cognitive impairment at T2 and T4 but not at T3. CONCLUSION: This is the first study to establish the existence of heterogeneous cognitive trajectories based on clinically significant thresholds of self-perceived cognitive impairment. The findings have important implications on the window for screening and management of post-chemotherapy cognitive impairment.

Association of mitochondrial DNA content in peripheral blood with cancer-related fatigue and chemotherapy-related cognitive impairment in early-stage breast cancer patients: a prospective cohort study.

PURPOSE: Cancer-related fatigue (CRF) and chemotherapy-related cognitive impairment (CRCI) are reported to be associated with mitochondrial dysfunction. Hence, mitochondrial DNA (mtDNA) content, a biomarker of mitochondrial dysfunction, is hypothesized to correlate with the onset of CRF and CRCI. This study aims to evaluate the association between peripheral blood mtDNA content reduction and severity of CRF and CRCI in patients receiving chemotherapy. METHODS: This was a prospective cohort study. Early-stage breast cancer patients receiving anthracycline- or taxane-based chemotherapy were recruited. CRF was assessed using MFSI-SF, and CRCI was assessed using FACT-Cog and CANTAB at two timepoints: baseline (T1; prior to treatment) and 6 weeks after initiation of treatment (T2). mtDNA content was measured at both timepoints using real-time quantitative polymerase chain reaction. Multiple logistic regression was utilized to evaluate the association between mtDNA reduction and worsening of CRF and CRCI, adjusting for age, anxiety, insomnia, plasma cytokines concentrations, and other clinically important covariates. RESULTS: A total of 108 patients (age 52.0 ± 9.2 years; 82.4% Chinese; 64.8% receiving anthracycline-based chemotherapy) were recruited. Proportions of patients with worsening of CRF increased from the lower to the upper quartiles of mtDNA reduction (22.2, 33.3, 55.6, and 63.0% in quartiles 1, 2, 3, and 4, respectively, p = 0.001 for trend). Reduction of mtDNA content was significantly greater among those with worsening of CRF and CRCI compared to those without CRF [mean reduction (± SD): 36.5 (46.1) vs. 9.4 (34.5), p < 0.001]. After adjusting for covariates, every 1-unit reduction of the mtDNA content was associated with a 4% increased risk for worsening of CRF (95% CI, 1-6%; p = 0.009). CONCLUSIONS: This is the first study to show that the reduction of mtDNA content in peripheral blood is associated with the onset of CRF in patients receiving chemotherapy. Further validation studies are required to confirm the findings.

Psychometric properties and measurement equivalence of the Multidimensional Fatigue Syndrome Inventory- Short Form (MFSI-SF) amongst breast cancer and lymphoma patients in Singapore.

BACKGROUND: Currently, several fatigue measurement instruments are available to evaluate and measure cancer-related fatigue. Amongst them, Multidimensional Fatigue Syndrome Inventory-Short Form (MFSI-SF) is a self-reported instrument and a multidimensional scale that aims to capture the global, somatic, affective, cognitive and behavioural symptoms of fatigue. This study examines the psychometric properties and measurement equivalence of the English and Chinese versions of MFSI-SF in breast cancer and lymphoma patients in Singapore. METHODS: Patients were recruited from National Cancer Centre Singapore. Validity, reliability and responsiveness of MFSI-SF were evaluated in this study. Convergent validity was evaluated by correlating total and subscales of MFSI-SF to known related constructs in EORTC QLQ-C30. Known group validity was assessed based on patients' cancer stage, pain, insomnia and depression symptoms. Reliability was evaluated by Cronbach's α. Responsiveness analyses were performed with patients who have undergone at least one cycle of chemotherapy. Multiple regression was used to compare the total and subscale scores of MSFI-SF between the two language versions. RESULTS: Data from 246 (160 English and 86 Chinese version) breast cancer and lymphoma patients were included in the study. Moderate to high correlations were observed between correlated MFSI-SF subscales and EORTC QLQ-C30 domains (|r| = 0.524 to 0.774) except for a poor correlation (r = 0.394) observed between MFSI-SF vigour subscale and EORTC QLQ-C30 role functioning subscale. Total MFSI-SF scores could differentiate between patients with higher depression, pain and insomnia status. Internal consistency of MFSI-SF was also high (α = 0.749 to 0.944). Moderate correlation was observed between change in total MFSI-SF score and change in fatigue symptom scale score and global QoL score on EORTC QLQ-C30 (|r| = 0.478 and 0.404 respectively). Poor correlations were observed between change in scores of hypothesised subscales (|r| = 0.202 to 0.361) except for a moderate correlation between change in MFSI-SF emotional fatigue score and change in EORTC QLQ-C30 emotional functioning domain score. Measurement equivalence was established for all subscales and total MFSI-SF score except for the emotional and vigour subscales. CONCLUSIONS: This study supports the use of MFSI-SF as a reasonably valid scale with good internal consistency for measuring fatigue levels in the Singapore cancer population.

Minimal Clinically Important Difference of the Multidimensional Fatigue Symptom Inventory-Short Form (MFSI-SF) for Fatigue Worsening in Asian Breast Cancer Patients.

CONTEXT: The minimal clinically important difference (MCID) of the Multidimensional Fatigue Symptom Inventory-Short Form (MFSI-SF), a questionnaire that measures cancer-related fatigue, has not been established in patients with cancer. OBJECTIVES: This study aims to determine the MCID of the MFSI-SF. METHODS: Breast cancer patients completed the MFSI-SF and the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC-QLQ-C30) before chemotherapy and at least three weeks later. The EORTC-QLQ-C30 fatigue scale (EORTC-FA) was used as an anchor, and a receiver operating characteristic (ROC) curve was also used to identify the optimal MCID cut-off for fatigue deterioration. A distribution-based approach used one-third of the SD, half of the SD, and one SEM of the total MFSI-SF score to determine the MCID. RESULTS: A total of 201 patients were analyzed. Change scores of the MFSI-SF and EORTC-FA were moderately correlated (r = 0.47, P < 0.001). The EORTC-FA-anchored MCID was 8.69 points (95% CI: 4.03-13.34). The MCID attained from the ROC curve method was 4.50 points (sensitivity: 68.8%; specificity: 64.1%). For the distribution-based approach, the MCIDs corresponding to one-third of the SD, half of the SD, and one SEM were 5.39, 8.99, and 10.79 points, respectively. CONCLUSION: The MCID of the MFSI-SF identified by all approaches ranged from 4.50 to 10.79 points. The MCID can be used to interpret the clinical significance of fatigue deterioration in patients with breast cancer and to determine sample sizes for future clinical trials.

Evaluation of plasma brain-derived neurotrophic factor levels and self-perceived cognitive impairment post-chemotherapy: a longitudinal study.

BACKGROUND: Preliminary evidence suggests that changes in plasma brain-derived neurotrophic factor (BDNF) levels may contribute to the occurrence of chemotherapy-associated cognitive impairment (CACI), and a previous study suggested that carriers of the BDNF Met homozygous genotype are protected from CACI. METHODS: This multicenter, prospective cohort study involved chemotherapy-receiving early-stage breast cancer (ESBC) patients. Self-perceived cognitive function was longitudinally assessed using the validated FACT-Cog (ver. 3) across three time points: Prior to chemotherapy (T1), during chemotherapy (T2), and at the end of chemotherapy (T3). Plasma BDNF levels were quantified using enzyme-linked immunosorbent assay. Genotyping was performed using Sanger Sequencing. RESULTS: A total of 51 chemotherapy-receiving ESBC patients (mean age: 52.6 ± 9.5 years) were recruited, and 11 patients (21.6%) reported subjective cognitive impairment post-chemotherapy. Overall, there was a reduction in median plasma BDNF levels over time (T1: 5423.0 pg/ml; T2: 5313.6 pg/ml; T3: 4050.3 pg/ml; p < 0.01). After adjusting for confounding factors, longitudinal analysis revealed that BDNF levels were associated with self-reported concentration deficit (p = 0.032). Carriers of Val/Val (p = 0.011) and Val/Met (p = 0.003) BDNF genotypes demonstrated a significant reduction in plasma BDNF levels over time; however, plasma BDNF levels were similar across all time points among Met homozygous carriers (p = 0.107). CONCLUSION: There was a statistically significant change in BDNF levels post-chemotherapy in ESBC patients, and plasma BDNF levels were associated with self-perceived concentration deficit in patients receiving chemotherapy.

Perceptions and Barriers of Survivorship Care in Asia: Perceptions From Asian Breast Cancer Survivors.

PURPOSE: With the long-term goal to optimize post-treatment cancer care in Asia, we conducted a qualitative study to gather in-depth descriptions from multiethnic Asian breast cancer survivors on their perceptions and experiences of cancer survivorship and their perceived barriers to post-treatment follow-up. METHODS: Twenty-four breast cancer survivors in Singapore participated in six structured focus group discussions. The focus group discussions were voice recorded, transcribed verbatim, and analyzed by thematic analysis. RESULTS: Breast cancer survivors were unfamiliar with and disliked the term "survivorship," because it implies that survivors had undergone hardship during their treatment. Cognitive impairment and peripheral neuropathy were physical symptoms that bothered survivors the most, and many indicated that they experienced emotional distress during survivorship, for which they turned to religion and peers as coping strategies. Survivors indicated lack of consultation time and fear of unplanned hospitalization as main barriers to optimal survivorship care. Furthermore, survivors indicated that they preferred receipt of survivorship care at the specialty cancer center. CONCLUSION: Budding survivorship programs in Asia must take survivor perspectives into consideration to ensure that survivorship care is fully optimized within the community.

Psychometric properties and measurement equivalence of the English and Chinese versions of the Beck Anxiety Inventory in patients with breast cancer.

BACKGROUND: There is a lack of psychometric data for both the English and Chinese versions of Beck Anxiety Inventory (BAI) to support its usage among breast cancer patients. This study examined the psychometric properties and measurement equivalence of the English and Chinese versions of BAI among breast cancer patients in Singapore. METHODS: Patients were recruited from two major cancer centers in Singapore. The criterion and construct validity of BAI was assessed by its correlation strength with (1) the emotional functioning subdomain of EORTC QLQ-C30 and (2) constructs related to anxiety, namely fatigue, dyspnea, and quality of life. The known-group validity was assessed according to the patients' breast cancer stage, religious beliefs, and emotional functioning levels. The internal consistency of the BAI domains was evaluated using Cronbach's alpha coefficient. Regression analysis was performed to compare the BAI total and domain scores between the two language versions. RESULTS: Data from 244 patients (144 English-speaking and 100 Chinese-speaking) were analyzed. For both language versions, the BAI total scores correlated moderately with the EORTC QLQ-C30 emotional functioning subdomain (r = -0.655 and -0.601). Correlations with fatigue, quality of life, and dyspnea were moderate (|r| = 0.456-0.606). Patients with poorer emotional functioning reported higher anxiety levels, establishing known-group validity. All BAI domains demonstrated satisfactory internal consistencies (α = 0.74-0.87), except for the panic domain (α = 0.57-0.61). Possible measurement equivalence between the language versions was established. CONCLUSION: Both English and Chinese versions of BAI are valid, reliable, and possibly equivalent for future use.

A culturally adapted survivorship programme for Asian early stage breast cancer patients in Singapore: A randomized, controlled trial.

BACKGROUND: As cancer mortality rates improve in Singapore, there is an increasing need to improve the transition to posttreatment survivorship care. This study aimed to evaluate the effectiveness of a psychoeducation group (PEG) intervention program compared with usual care to reduce distress for physical symptom and psychological aspects in Asian breast cancer survivors who have completed adjuvant chemotherapy. METHODS: This was a randomized, controlled trial comprising 72 Asian early stage breast cancer survivors who were randomized into the PEG (n = 34) or the control (n = 38) arm. The participants in the PEG arm underwent a weekly multidisciplinary PEG program delivered in a group format over 3 weeks coupled with cultural adaptation. Both arms were assessed at baseline and 2 months after intervention using the Rotterdam Symptom Checklist, Beck Anxiety Inventory, and EORTC QLQ-C30. A satisfaction questionnaire was also conducted among those survivors who have participated in the PEG program. Effective sizes were calculated using Cohen d. RESULTS: The mean age ± SD of all participants was 53.0 ± 8.9 years, with the majority being Chinese (84.7%) and Malay (6.9%), and clinical characteristics were well balanced in both arms. Compared to the control arm, the PEG arm showed a significantly greater reduction in physical symptom distress (d = 0.76, P = .01) and fatigue (d = 0.49, P = .04). The 82.4% of the participants in the intervention group responded to the satisfaction questionnaire, and the majority (92.9%) agreed that the overall duration of the PEG intervention program was appropriate. CONCLUSIONS: A culturally adapted PEG program was effective in reducing physical symptom distress in Asian breast cancer survivors. (ClinicalTrials.gov: NCT02600299).

Impact of TNF-α (rs1800629) and IL-6 (rs1800795) Polymorphisms on Cognitive Impairment in Asian Breast Cancer Patients.

OBJECTIVE: Expression of pro-inflammatory cytokines is influenced by single nucleotide polymorphisms (SNPs) in the promoter regions of the pro-inflammatory cytokine genes, and cytokines are associated with the occurrence of post-chemotherapy cognitive impairment. Hence, the aim of this study was to evaluate the associations between two common pro-inflammatory cytokine gene polymorphisms namely, IL6-174 (rs1800795 G>C) and TNF-308 (rs1800629 G>A), and chemotherapy-associated cognitive impairment (CACI) among Asian early-stage breast cancer patients. In addition, the differential effect of these SNPs on plasma IL-6 and TNF-α levels, and the associations of plasma IL-6 and TNF-α levels with CACI were also assessed. METHODS: Asian early-stage breast cancer patients (Stage I to III) receiving chemotherapy were prospectively recruited from two cancer centers in Singapore. Patients' cognitive function was longitudinally assessed using the validated FACT-Cog (ver. 3) and an objective computerized battery, Headminder™ at three-time points. Plasma IL-6 and TNF-α levels were analyzed using the multiplex immunoassay, and genotyping was performed using Sanger sequencing. Regression analyses and generalized estimating equation were utilized for statistical analysis. RESULTS: A total of 125 patients were included (mean age: 50.3; Chinese: 80.8%; post-menopausal: 48.0%; 68.0% received anthracycline-based chemotherapy). 36.8% patients experienced self-perceived cognitive impairment, detected in memory (32.8%) and attention (34.2%) domains. Patients with higher levels of anxiety (p<0.001) and insomnia (p = 0.003) also reported more self-perceived cognitive impairment. Higher plasma concentrations of IL-6 were associated with greater severity of self-perceived cognitive impairment (p = 0.001). Polymorphisms of cytokine genes were not associated with expression of plasma cytokines. CONCLUSION: Present findings further contribute to the growing evidence that supports the role of the pro-inflammatory cytokine IL-6 in the occurrence of cognitive impairment post-chemotherapy. However, genetic polymorphism of these cytokines did not play a major role to the cytokine fluctuations as well as cognitive impairment in this cohort. With an increasing evidence to support the cytokine hypothesis, future studies should investigate the role of anti-inflammatory agents in mitigating the cognitive impairment associated with chemotherapy.

Brain-derived neurotrophic factor genetic polymorphism (rs6265) is protective against chemotherapy-associated cognitive impairment in patients with early-stage breast cancer.

BACKGROUND: Brain-derived neurotrophic factor (BDNF), a neurotrophin that regulates neuronal function and development, is implicated in several neurodegenerative conditions. Preliminary data suggest that a reduction of BDNF concentrations may lead to postchemotherapy cognitive impairment. We hypothesized that a single nucleotide polymorphism (rs6265) of the BDNF gene may predispose patients to cognitive impairment. This study aimed to evaluate the effect of BDNF gene polymorphism on chemotherapy-associated cognitive impairment. METHODS: Overall, 145 patients receiving chemotherapy for early-stage breast cancer (mean age: 50.8 ± 8.8 y; 82.1% Chinese) were recruited. Patients' cognitive functions were assessed longitudinally using the validated Functional Assessment of Cancer Therapy-Cognitive Function (v.3) and an objective computerized tool, Headminder. Genotyping was performed using Sanger sequencing. Logistic regression was used to evaluate the association between BDNF Val66Met polymorphism and cognition after adjusting for ethnicity and clinically important covariates. RESULTS: Of the 145 patients, 54 (37%) reported cognitive impairment postchemotherapy. The Met/Met genotype was associated with statistically significant lower odds of developing cognitive impairment (odds ratio [OR] = 0.26; 95% CI: 0.08-0.92; P = .036). The Met carriers were less likely to experience impairment in the domains of verbal fluency (OR = 0.34; 95% CI: 0.12-0.90; P = .031) and multitasking ability (OR = 0.37; 95% CI: 0.15-0.91; P = .030) compared with the Val/Val homozygote. No associations were observed between Headminder and the BDNF Val66Met polymorphism. CONCLUSIONS: This is the first study to provide evidence that carriers of the BDNF Met allele are protected against chemotherapy-associated cognitive impairment. Further studies are required to validate the findings.

Trajectory and risk factors for chemotherapy-induced nausea and vomiting in Asian patients with head and neck cancer.

BACKGROUND: The purpose of this study was to analyze the trajectory of and risk factors for chemotherapy-induced nausea and vomiting in Asian patients with head and neck cancer. METHODS: Adult patients with head and neck cancer scheduled to receive cisplatin-based chemotherapy were recruited for the study. Clinical events were collated from standardized diaries. RESULTS: Two hundred thirty-five patients were included in the analyses. The majority (75.7%) was men, Chinese (81.7%), and manifested nasopharyngeal cancer (83.4%). The overall incidence of significant nausea and vomiting was 73.7% and 24.7%, respectively, with single-day cisplatin regimens of 48.9% and 28.9%, respectively, with the multiple-day cisplatin regimen. Patients using complementary alternative medicine were less likely than others to achieve a complete response to antiemetics. CONCLUSION: Although postchemotherapy vomiting is relatively well controlled in Asian patients with head and neck cancer, postchemotherapy nausea remains problematic in this population.

Minimal clinically important difference (MCID) for the functional assessment of cancer therapy: cognitive function (FACT-Cog) in breast cancer patients.

OBJECTIVES: This is the first reported study to determine the minimal clinically important difference (MCID) of Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog), a validated subjective neuropsychological instrument designed to evaluate cancer patients' perceived cognitive deterioration. STUDY DESIGN AND SETTING: Breast cancer patients (n = 220) completed FACT-Cog and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC-QLQ-C30) at baseline and at least 3 months later. Anchor-based approach used the validated EORTC-QLQ-C30-Cognitive Functioning scale (EORTC-CF) as the anchor for patients who showed minimal deterioration and a receiver operating characteristic (ROC) curve to identify the optimal MCID cutoff for deterioration. Distribution-based approach used one-third standard deviation (SD), half SD, and one standard error of measurement (SEM) of the total FACT-Cog score (148 points). RESULTS: There was a moderate correlation between changes in FACT-Cog and EORTC-CF scores (r = 0.43; P < 0.001). The EORTC-CF-anchored MCID was 9.6 points (95% confidence interval: 4.4, 14.8). The MCID from the ROC method was 7.5 points (area under the curve: 0.75; sensitivity: 75.6%; specificity: 68.8%). For the distribution-based approach, the MCIDs corresponding to one-third SD, half SD, and one SEM were 6.9, 10.3, and 10.6 points, respectively. Combining the approaches, the MCID identified for FACT-Cog ranged from 6.9 to 10.6 points (4.7-7.2% of the total score). CONCLUSION: The estimates of 6.9-10.6 points as MCID can facilitate the interpretation of patient-reported cognitive deterioration and sample size estimates in future studies.

Psychometric properties and measurement equivalence of the English and Chinese versions of the functional assessment of cancer therapy-cognitive in Asian patients with breast cancer.

OBJECTIVE: This study was designed to examine the psychometric properties and measurement equivalence of the English and Chinese versions of the Functional Assessment of Cancer Therapy-Cognitive Function (Version 3) (FACT-Cog) in multiethnic Asian patients with breast cancer. METHODS: This prospective study involved patients with breast cancer from the National Cancer Centre Singapore. The concurrent validity of the FACT-Cog was assessed according to its strength of correlation with the validated European Organization for Research and Treatment of Cancer Quality of Life Core Questionnaire 30 cognitive functioning scale, and its association with fatigue, global health status, and anxiety. The known-group validity was assessed on the basis of receipt of chemotherapy. Factor analysis was conducted to ascertain the one-factor structure of each cognitive domain. The reliability was evaluated by using Cronbach's alpha and intraclass correlation coefficient within the cognitive domains. Multiple regression analyses were performed to compare the total scores between the two language versions, adjusting for covariates. RESULTS: A total of 185 English-speaking and 143 Chinese-speaking patients were recruited. Both the English and Chinese FACT-Cog total scores correlated strongly with the European Organization for Research and Treatment of Cancer Quality of Life Core Questionnaire 30 cognitive functioning scale scores (r = 0.725 and 0.646), whereas correlations with fatigue, anxiety, and global health status were weak to moderate (|r| = 0.376-0.589). Regarding the known-group validity, more severe perceived cognitive disturbance was observed among patients receiving chemotherapy than among those who were not for both versions (P = .010 and .008, respectively). Internal consistencies within the cognitive domains were high (Cronbach's α 0.707-0.929), and test-retest reliability was satisfactory for both versions (intraclass correlation coefficient 0.762 and 0.697). The measurement equivalence between the English and Chinese versions was established for all domains except the multitasking domain. CONCLUSION: The English and Chinese versions of the FACT-Cog are valid, reliable, and equivalent for clinical and research use.