Assessing objective cognitive impairments in cancer survivors: Features and validity of measures for research and clinical applications.

Objective: This narrative review aims to (1) identify neuropsychological tests for assessing cognitive function impairment in patients with cancer, specifically in the domains of attention and memory, (2) summarize the characteristics of these tests, including cognitive function domains, test content, readability, and psychometric quality, and (3) evaluate the feasibility of each test in cancer care. Methods: Data sources include published test manuals, documents from official web pages, and published journal articles. Results: Our study identified eight neuropsychological tests that are most frequently used to assess the attention and memory domains of objective cognitive function in patients with breast cancer. These tests include the California Verbal Learning Test, Hopkins Verbal Learning Test, Rey Auditory Verbal Learning Test, Rey-Osterrieth Complex Figure, CNS Vital Signs, Wechsler Adult Intelligence Scale, Wechsler Memory Scale, and Trail Making Test. They demonstrate acceptable evidence of psychometric quality and varying degrees of feasibility. Test feasibility is influenced by factors such as short testing time, brevity and comprehensiveness, clear cognitive domain distinctions, availability of normative data, minimal practice effects, ease of administration, and limited attention-span requirements. These attributes determine a test's feasibility for use in cancer care. Among the evaluated measures, the California Verbal Learning Test for memory, the Trail Making Test for attention, and the CNS Vital Signs for comprehensive assessment emerge as the most practical choices for cancer care. Conclusions: The assessment and management of cognitive function impairment are crucial for enhancing the quality of life in cancer survivors. Nurses should possess knowledge of assessment tools for early detection and the ongoing monitoring of this symptom's progression.

The role of cytokines and Indolamine-2.3 dioxygenase in experiencing a psycho-neurological symptom cluster in hematological cancer patients: IL-1alpha, IL-1beta, IL-4, IL-6, TNF-alpha, kynurenine, and tryptophan.

OBJECTIVE: This study examined (a) whether there are a subgroup of cancer patients experiencing the selected psycho-neurological symptoms as a cluster (depression, cognitive impairment, fatigue, sleep disturbance, and pain); (b) whether demographic and clinical characteristics and pro-inflammatory cytokines (IL-1α, IL-1ß, IL-4, IL-6, TNF-alpha) are associated with subgroup membership; and (c) whether the activity of indolamine-2.3 dioxygenase(IDO) is associated with pro-inflammatory cytokine activity and psycho-neurological symptom cluster experience. METHODS: This was a prospective cohort study where 149 hematologic patients were recruited from a university hospital and 65 healthy volunteers provided control data. Latent profile analyses were conducted to identify subgroups at two time points: the last day of chemotherapy and 1 week after chemotherapy completion. Influencing factors of subgroup membership were examined by logistic regression. RESULTS: A substantial number of patients (33%, 34% at each time point) experienced the selected psycho-neurological symptoms as a cluster. Older age and elevated IL-1α and IL-6 were associated with experiencing the psycho-neurological symptom cluster. IDO activity was higher in the patients experiencing psycho-neurological symptom cluster; and was positively associated with IL-6. Symptom severity, IL-1α, IL-6, and IDO activity were all significantly higher in cancer patients than in the healthy controls. The findings were preserved across time points. CONCLUSIONS: The activation of pro-inflammatory cytokines and their cross-talk with IDO may be a common biological mechanism, underlying a psycho-neurological symptom cluster experience. The novel approaches for symptom assessment and management can be developed by assessing multiple psycho-neurological symptoms as a cluster and by targeting their common biological pathway.

Neuropsychological Effects of Chemotherapy: Systematic Review of Longitudinal Studies on Objective Cognitive Impairment in Breast Cancer Patients.

BACKGROUND: Findings from longitudinal studies can provide more conclusive evidence as to the impact of chemotherapy on cognitive functioning. OBJECTIVES: This study aimed to ( a ) synthesize the evidence from longitudinal studies of the neuropsychological effects associated with chemotherapy in breast cancer patients, ( b ) identify associated factors, and ( c ) evaluate methodological issues. METHODS: Data were extracted from PubMed, EMBASE, CINAHL, PsycINFO, and the Cochrane Library. Inclusion criteria included the original study with the breast cancer sample, validated measure, and at least 1 baseline data point before and after chemotherapy began. Data accrued for sample characteristics, data-collection time points, statistical methods for longitudinal data analysis, outcome measures, and major findings (eg, longitudinal changes in cognitive function). RESULTS: We selected 42 articles for this review. The sample sizes ranged from 20 to 610, and most recruited were younger than 70 years. We found a trend across studies-statistically significant objective cognitive function deteriorations in severity and prevalence after initiating chemotherapy compared with a control group or relative to their baseline observations. A subsample, as high as 65%, experienced marked declines in cognitive function after initiating chemotherapy. The memory domain was most affected. The consistently associated factors were education, IQ, and regimen. Major methodological concerns were the measurement-the wide range of neuropsychological tests and a test's unclear domains. CONCLUSION: Chemotherapy affects objective cognitive function in some subsets. The highest-impact time point, mechanisms, and clinical significance of chemotherapy-associated cognitive impairment need additional evidence. IMPLICATION FOR PRACTICE: Clinicians must assess and manage cognitive impairment during and after chemotherapy.

Psychometric Evaluation of the Korean Version of the Functional Assessment of Chronic Illness Therapy-Fatigue.

BACKGROUND: The Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-Fatigue) instrument is a fatigue measure widely used on patients with cancer worldwide. The psychometric quality of the Korean version of the FACIT-Fatigue instrument has never been systematically evaluated. PURPOSE: The purpose of this study was to assess the reliability and validity of the Korean version of the FACIT-Fatigue instrument. METHODS: This study used data collected from 170 patients with cancer and 120 healthy individuals. Internal consistency reliability was analyzed using Cronbach's α and item-total correlation. Construct validity was analyzed using confirmatory factor analysis, and known-group validity was tested using t tests. Convergent validity was analyzed using Pearson's correlation with pain and functional limitations. Predictive validity was analyzed using receiver operating characteristic curves. RESULTS: The Cronbach's α was .93 for the reliability evaluation, and the item-total correlation ranged from .27 to .84. In the construct validity evaluation, the bifactor model showed good fit (Q = 1.93, comparative fit index = .97, Tucker-Lewis index = .96, root mean square error of approximation = .05), indicating using the instrument's total score to be more appropriate than using the subscale scores (explained common variance = .76, ω = .95, ωH = .85, ωH/ω = .89). The group of patients with cancer showed significantly higher fatigue than the healthy subject group, showing known-group validity (t = -10.40, p < .05). Fatigue showed significant and strong correlations with functional limitations and pain (all ps < .001). The area under the curve was .81 (cutoff point = 40, Youden's index: 0.47, sensitivity: 77.60%, specificity: 73.04%), verifying that the instrument is predictive of higher fatigue severity in patients with cancer. CONCLUSIONS/IMPLICATIONS FOR PRACTICE: The Korean version of the FACIT-Fatigue instrument was shown to be reliable and valid. Its construct validity supports the use of the total scale score rather than the subscale scores.

Association of chemotherapy and subjective cognitive impairment in breast cancer patients: Meta-analysis of longitudinal prospective cohort studies.

PURPOSE: This meta-analysis with longitudinal prospective cohort studies aimed to (a) determine whether chemotherapy is associated with time-dependent subjective cognitive impairment outcomes in breast cancer patients, and (b) identify the time point with the highest impact of chemotherapy on subjective cognitive impairment. METHODS: Data were gathered from PubMed, EMBASE, CINAHL, PsycInfo, and the Cochrane Library. The mean differences of the subjective cognitive impairment level between the chemotherapy-treated patients and controls (patients not treated by chemotherapy and healthy subjects) were calculated using effect sizes (Hedges' g) by clinical time periods. The five clinical time periods were (a) baseline, (b) during chemotherapy, (c) within 1 month postchemotherapy, (d) within 1 year postchemotherapy, and (e) 1 year or longer postchemotherapy. RESULTS: Longitudinal data from nine data sets from 13 studies were pooled and analyzed. At baseline, chemotherapy-treated patients showed slightly better subjective cognitive impairment compared to patients not treated by chemotherapy and did not differ from healthy controls. Yet, the chemotherapy-treated patients had significantly worse subjective cognitive impairment compared to both type of controls after initiating chemotherapy. The effect sizes for the group differences were larger for the group comparison with healthy controls than the nonchemotherapy control (-0.50 vs. -0.19). The largest effects were found within 1 month postchemotherapy (-0.85), suggesting the acute impact of chemotherapy. CONCLUSIONS: Chemotherapy is associated with subjective cognitive impairment. The impact of chemotherapy appears to be an acute rather than a chronic side effect. Clinicians must consider including the assessment and management of subjective cognitive impairment in their routine practice.

Radio Frequency Induction Welding of Silver Nanowire Networks for Transparent Heat Films.

Transparent heat films (THFs) are attracting increasing attention for their usefulness in various applications, such as vehicle windows, outdoor displays, and biosensors. In this study, the effects of induction power and radio frequency on the welding characteristics of silver nanowires (Ag NWs) and Ag NW-based THFs were investigated. The results showed that higher induction frequency and higher power increased the welding of the Ag NWs through the nano-welding at the junctions of the Ag NWs, which produced lower sheet resistance, and improved the adhesion of the Ag NWs. Using the inductive welding condition of 800 kHz and 6 kW for 60 s, 100 ohm/sq of Ag NW thin film with 95% transmittance at 550 nm after induction heating could be decreased to 56.13 ohm/sq, without decreasing the optical transmittance. In addition, induction welding of the Ag NW-based THFs improved haziness, increased bending resistance, enabled higher operating temperature at a given voltage, and improved stability.

Determinants of the Higher Prevalence and Severity of Subjective Cognitive Impairment in Cancer Patients Compared to Healthy Subjects: Fatigue and Stress.

This study examined whether (a) cancer patients in two cohorts reported greater subjective cognitive impairment (SCI) in prevalence and severity than noncancer healthy controls; and (b) selected psychoneurological factors (fatigue, stress, and sleep disturbance) contribute to such differences. Data from 60 prechemotherapy cancer patients, 81 active-chemotherapy cancer patients, and 116 noncancer healthy controls were analyzed using hierarchical regressions. The prevalence rate of SCI was higher in the prechemotherapy cancer cohort (41.6%) and in the active-chemotherapy cancer cohort (46.9%) than in healthy controls (21.5%; p < .001). SCI severity was also higher in two cancer cohorts than noncancer controls (p < .001). The two cancer cohorts were similar to each other in severity and prevalence of SCI. The two cancer cohorts experienced higher fatigue, stress, and sleep disturbance than healthy controls. After controlling for psychoneurological factors, however, the two cancer cohorts did not differ from healthy controls in experiencing SCI in prevalence and severity. Psychoneurological factors may be a major determinant of the higher prevalence and severity of SCI in cancer patients.

Thermogelling Inclusion Complex System for Fine-Tuned Osteochondral Differentiation of Mesenchymal Stem Cells.

How to control osteochondral differentiation of mesenchymal stem cells at a proper stage is a key issue for articular cartilage regeneration. To solve this problem, injectable scaffolds with different chemical functional groups were designed by introducing one equivalent of α-cyclodextrin (α-CD) carboxylate and α-CD phosphate along poly(ethylene glycol)-poly(l-alanine) (PEG-L-PA) block copolymers. Dynamic light scattering, transmission electron microscopy images, and two-dimensional NMR spectra indicated that the PEG-L-PA block copolymers formed inclusion complexes with α-CD derivatives. Aqueous solutions of PEG-L-PA block copolymers (P), α-CD carboxylate/PEG-L-PA block copolymers (PCC), and α-CD phosphate/PEG-L-PA block copolymers (PCP) underwent sol-to-gel transition as the temperature increased. The storage moduli of P, PCC, and PCP gels ranged from 1000 to 1300 Pa at 37 °C. Tonsil-derived mesenchymal stem cells (TMSCs) were incorporated in situ in the gel during thermogelation of P, PCC, and PCP, which became the three-dimensional cell culture systems with different functional groups. After 21 days of incubation of TMSCs in the P, PCC, and PCP systems, the chondrogenic differentiation biomarker of type II collagen significantly increased in the P system, whereas the osteogenic biomarkers of osteocalcin and runt-related transcription factor 2 significantly increased in the PCP system. Both chondrogenic and osteogenic biomarkers were highly expressed in the PCC system. This study proved that thermogelling inclusion complex systems consisting of PEG-L-PA block copolymers and α-CD derivatives could be an excellent injectable matrix for fine-controlling osteochondral differentiation of mesenchymal stem cells.

Comparative evaluations of single-item pain-intensity measures in cancer patients: Numeric rating scale vs. verbal rating scale.

AIMS AND OBJECTIVES: To evaluate the psychometric quality of two single-item pain-intensity measures: the Numeric Rating Scale (NRS) and the Verbal Rating Scale (VRS). BACKGROUND: Measuring pain intensity is a vital step in initiating symptom management and evaluating the effectiveness of interventions with cancer patients. Single-item pain-intensity measures of the NRS and VRS format have been evaluated to be acceptable for use in clinical practice and research; however, evidence to choose one over the other, as a standardised pain-assessment format, is insufficient. DESIGN: Descriptive correlational study. The study was guided and reported following the STROBE guideline. METHODS: Data accrued at two time points during cancer treatment with a total of 249 patients treated in a Korean University Hospital. Two single-item measures were constructed to assess pain intensity over 1 week. The Brief Pain Inventory (BPI; pain intensity subscale and interference subscale) and the functional assessment of chronic illness therapy-fatigue were the criterion. Convergent and concurrent validity were tested with Pearson's correlations. RESULTS: In the convergent-validity evaluation of the cross-sectional association with the BPI, the NRS showed a much higher level of association than the VRS (0.81 versus 0.61). In convergent validity with a longitudinal association with the BPI, the NRS score change had a much higher level of association (0.61 versus 0.37). In concurrent-validity evaluation, the NRS and VRS showed similar levels of associations with fatigue (-0.48 versus -0.49). Yet, the NRS showed statistically higher levels of correlation with functional limitations than the VRS (0.55 versus 0.42), comparable to the concurrent validity of the BPI. CONCLUSION: The NRS showed higher validity than VRS when assessing overall pain intensity over the past week. RELEVANCE TO CLINICAL NURSING: Pain assessment is a vital role of nurses in caring for patients with cancer. Current study findings support the use of the single-item NRS pain measure to assess global pain intensity over the past week.

Systematic review of longitudinal studies on chemotherapy-associated subjective cognitive impairment in cancer patients.

OBJECTIVES: This systematic review of longitudinal studies, assessing subjective cognitive impairment (SCI) reported by adult cancer patients, aimed to summarize evidence on the impact of chemotherapy on SCI, identify moderators of SCI, and evaluate methodological issues. METHODS: Data accrued from Pubmed, EMBASE, CINAHL, PsychInfo, and the Cochrane library. Inclusion criteria were original studies, an exclusively adult sample, valid and reliable subjective cognitive measures, and at least one baseline data point prior to and another after the initiation of chemotherapy. Data were collected on the sample composition, data-collection time points, outcome measures, statistical analysis, and major findings (ie, longitudinal changes in prevalence, severity, and associated factors). RESULTS: Forty articles published between 2004 and 2019 were retained: 21 examined chemotherapy-treated patients only, and 19 employed control groups. Findings were mixed, with slightly more studies supporting the impact of chemotherapy on SCI. SCI tended to be more prevalent and severe after initiating chemotherapy, compared with patients' own baseline and controls not treated with chemotherapy. Impact appeared to be acute and more likely limited to subsamples. Most studies examining non-breast-cancer samples reported the lack or limited impact of chemotherapy on SCI. The most consistent moderators were depression and fatigue. Methodological issues regarding sampling design, measurement, and statistical analysis were discussed. CONCLUSION: More rigorously designed longitudinal studies would clarify direct and indirect effects of chemotherapy on SCI.

Iron Ion-Releasing Polypeptide Thermogel for Neuronal Differentiation of Mesenchymal Stem Cells.

A poly(ethylene glycol)-based thermogel can capture an iron ion (Fe3+) through a crown ether-like coordination bond between the oxygen atom and metal ions, thus, providing a sustained Fe3+-releasing system. Poly(ethylene glycol)-l-poly(alanine) thermogel was used in this study. The polypeptide forms a rather robust gel, and the degradation products are a neutral amino acid, which provides cyto-compatible neutral pH environments during the cell culture. During the heat-induced sol-to-gel transition at 37 °C, tonsil-derived mesenchymal stem cells (TMSCs) and iron ions were incorporated, leading to the formation of a three-dimensional matrix toward neuronal differentiation of the incorporated TMSCs. The initial concentration of the iron ions was varied between 0, 15, 30, and 60 mM. About 10% of the loaded iron ions was released over 21 days, which continuously supplied iron ions to the cells. The incorporation of iron ions not only increased the gel modulus at 37 °C from 107 to 680 Pa, but also promoted cell aggregation with a significant secretion of the cell adhesion signal of FAK. Expression of biomarkers related to the neuronal differentiation of TMSCs, including NFM, MAP2, GFAP, NURR1, NSE, and TUBB3, increased 4-35-fold at the mRNA level in the Fe3+-containing system compared to that of the system without Fe3+. Immunofluorescence studies also confirmed pronounced cell aggregation and a significant increase in neuronal biomarkers at the protein level. This study suggests that an iron ion-releasing thermogelling system can be a promising injectable scaffold toward neuronal differentiation of stem cells.

Roles of biological and psychosocial factors in experiencing a psychoneurological symptom cluster in cancer patients.

PURPOSE: (a) To identify subgroups with unique psychoneurological symptom-cluster experience (depression, cognitive impairment, fatigue, sleep disturbance, and pain) and (b) to examine whether the selected demographic, clinical, psychological, and biological factors determine a symptom-cluster experience in cancer patients. METHOD: The sample included 203 patients with diverse cancer types recruited from a Korean university hospital. Latent profile analyses were conducted to identify subgroups. Influencing factors of subgroup membership (demographic/clinical variables, hemoglobin level, social support, and psychological stress) were included as covariates in latent profile analysis and analyzed by multinomial logistic regression. RESULTS: Latent profile analyses classified patients into two subgroups with a unique symptom cluster experience: patients experiencing high intensity in all symptoms within the cluster (the all-high-symptom subgroup, 71%) and patients experiencing low intensity in all symptoms within the cluster (all-low-symptom subgroup, 29%). The validity of the two subgroups was confirmed by the group classification accuracy (97% of the all-low-symptom subgroup and 99% of the all-high-symptom subgroup) and by significant Wald's mean equality tests, showing each symptom (depression, cognitive impairment, fatigue, sleep disturbance, and pain) significantly differentiated the two subgroups (ps < .001). Psychological stress independently determined the subgroup membership. Patients with high levels of stress were more likely to be in the all-high-symptom group (OR = 4.69, p < .0001). Hemoglobin level, cancer diagnosis, social support, and previous chemotherapy experience did not influence group membership. CONCLUSIONS: A large number of patients experience five psychoneurological symptoms simultaneously due to psychological stress. Interventions targeted to stress would be beneficial for those patients.

The Brief Perceived Cognitive Impairment Scale-Korean: A Validation Study.

BACKGROUND: Practical brief measures are needed for clinicians and researchers to identify and effectively manage cognitive impairment in cancer patients. OBJECTIVE: This study evaluated the reliability (ie, internal consistency reliability) and validity (ie, construct, convergent, concurrent, and known-group validity) of the Brief Perceived Cognitive Impairment Scale-Korean (BPCIS-K). METHODS: From a university hospital, 249 cancer patients participated. The BPCIS-K was constructed with 6 items evaluating key aspects of cognitive impairment in cancer patients. For internal consistency reliability, Cronbach's α and item-total correlations were evaluated. For construct validity, confirmatory factor analysis was performed. For convergent validity, Pearson correlations were tested with the Functional Assessment of Cancer Therapy-Cognitive Function. For concurrent validity, Pearson correlations were tested with the Functional Assessment of Chronic Illness Therapy-Fatigue. For known-group validity, t tests were performed. RESULTS: The BPCIS-K showed high internal consistency reliability (Cronbach's α = .92; item-total correlations ranged from 0.76 to 0.81). Factor analysis confirmed the scale is unidimensional. It is highly associated with another validated cognitive impairment measure (r = -0.91, P < .001) and moderately correlated with a fatigue measure (r = -0.52, P < .001). In known-group validity, female and patients undergoing treatment experienced more severe impairment than did male patients and patient awaiting treatment (P = .05, P = .08, respectively). CONCLUSION: The BPCIS-K is valid and reliable for assessing cancer patients' perceived cognitive impairment, particularly in concentration, memory, and executive functions. IMPLICATION FOR PRACTICE: This study introduces a practical brief measure to clinicians and researchers.

Influence of Hip Fracture on Knee Pain During Postoperative Rehabilitation.

OBJECTIVE: To investigate whether fracture type, surgical procedure, or fracture grade affect knee pain during postoperative rehabilitation after a hip fracture. METHODS: We conducted a retrospective case-controlled study of 139 patients during postoperative rehabilitation after surgery for hip fractures. Patients were divided into two groups: patients experiencing knee pain during the first week of postoperative rehabilitation, and patients without knee pain. We compared the types of fracture, surgical procedure, and fracture grade between the two groups. RESULTS: We enrolled 52 patients (37.4%) with knee pain during the first weeks of postoperative rehabilitation. For type of fracture, knee pain was more common with intertrochanteric fracture than with femur neck fracture (48.8% vs. 21.1%, respectively; p=0.001). For the surgical procedure, there was no significant difference between the groups. For the fracture grade, the grades classified as unstable fractures were more common in the group of intertrochanteric fracture patients with knee pain than in those without knee pain (74.1% vs. 36.4%, respectively; p=0.002). CONCLUSION: Intertrochanteric fracture affected knee pain after hip fracture surgery more than did femur neck fracture, particularly in unstable fractures. Furthermore, there was no difference in each fracture type according to the surgical procedure. Careful examination and management for knee pain is needed in patients with hip fracture surgery.

Chemotherapy-associated cognitive impairments in Korean cancer patients: Risk factors and functional outcome.

OBJECTIVE: To identify those experiencing significant self-reported cognitive decline over 2 time points during chemotherapy, examine the risk factors for cognitive decline, and examine differences between those with and without significant decline in functional limitations. METHODS: This secondary analysis used data from 163 cancer patients, collected from a Korean University hospital. Significant decline was determined by 15% or more reduction from baseline in the Functional Assessment of Cancer Therapy-Cognitive Function. Multivariate logistic regression was performed to estimate risk factors. Repeated-measures ANOVA and t tests tested differences in groups with and without cognitive decline in cognitive impairment and functional limitation. RESULTS: About 31% (n = 51) experienced significant cognitive decline. Groups with and without decline significantly differed in cognitive-impairment changes over time (F = 238.49, P < .001) and in functional limitations at follow-up (t test, P < .01). Those experiencing increased fatigue over time (odds = 0.94, P < .05) and those who underwent 2 or more cycles between time 1 and 2 (odds = 2.61; P < .05) had higher risk of significant decline over time during chemotherapy. CONCLUSION: Significant cognitive decline occurred during active chemotherapy; attention to cognitive impairment should be given in the early phase of chemotherapy.

Putting evidence into practice: evidence-based interventions for depression.

Depression is a distressing emotion that occurs during various times of the cancer trajectory. Depression often goes unrecognized and untreated, which can significantly affect cost, quality of life, and treatment adherence. The Oncology Nursing Society's Putting Evidence Into Practice depression project team reviewed current literature to identify evidence-based interventions to reduce depression in people with cancer. Pharmacologic and nonpharmacologic interventions were evaluated, and opportunities for nurses to integrate recommendations into practice are offered in this article.

Subgroups of cancer patients with unique pain and fatigue experiences during chemotherapy.

CONTEXT: Some cancer patients experience pain and fatigue, whereas others experience only one of the two symptoms. Yet, it is not clear who experiences these unique patterns and why. OBJECTIVES: This study aimed to identify subgroups of cancer patients with unique pain and fatigue experiences in two different chemotherapy cycles to examine how selected factors influenced subgroup membership and identify how subgroups differed in concurrently measured functional limitation outcome. METHODS: The sample included 276 patients with diverse cancer types from four U.S. sites. To investigate subgroups, latent profile analyses were performed. Multinomial logistic regression and one-way analysis of variance-type analyses were conducted to examine the influencing variables of subgroup membership and to examine differences among subgroups in patient outcome. RESULTS: The high-pain/high-fatigue (HPHF) and low-pain/low-fatigue subgroups were found at both time points. The low-pain/high-fatigue subgroup was present only in the first chemotherapy cycle. Pain and fatigue levels significantly differentiated subgroups at each time point (all P<0.05). Across the two time points, experiencing higher depressed mood increased the risk to be in the HPHF subgroup (all P<0.01). The HPHF subgroup had the most serious limitations in activities (all P<0.01). CONCLUSION: This study confirmed the existence of a unique symptom experience of pain and fatigue. This pattern should be acknowledged for symptom assessment and management.

Comparison of groups with different patterns of symptom cluster intensity across the breast cancer treatment trajectory.

BACKGROUND: Comparing subgroups with different patterns of change in symptom intensity would assist in sorting out individuals at risk for more severe symptoms and worse functional outcomes. OBJECTIVES: The objectives of this study were to identify and compare subgroups of breast cancer patients with different patterns of change in a psychoneurological symptom cluster intensity across the treatment trajectory. METHODS: This secondary analysis used the data from 160 breast cancer patients undergoing chemotherapy or radiation treatment. Psychoneurological symptom cluster intensity was a composite score of 5 symptoms (depressed mood, cognitive disturbance, fatigue, insomnia, and pain) in a psychoneurological cluster at each of 3 time points (ie, at baseline and at 2 follow-ups after chemotherapy or radiation treatment). RESULTS: Five distinct subgroups representing different patterns of psychoneurological symptom cluster intensity during breast cancer treatment were identified: the gradually increasing pattern subgroup (group 1), the constantly low pattern subgroup (group 2), the start low with dramatic increase and decrease pattern subgroup (group 3), the constantly high pattern subgroup (group 4), and the start high with dramatic decrease and leveling pattern subgroup (group 5). Patients without previous cancer treatment experience, with higher level of education, treated with chemotherapy, and/or with more limitations at the baseline were more likely to follow the pattern group 4. Patients in group 4 had the most serious functional limitations measured at the second follow-up time point. CONCLUSION: The results suggest the need to evaluate interventions for specific subgroups and to examine the causal mechanisms underlying a psychoneurological symptom cluster. IMPLICATION: Clinicians should consider these diverse symptom experiences for assessment/management.

Analytical methods and issues for symptom cluster research in oncology.

PURPOSE OF REVIEW: Within a broader perspective on the next challenges in oncologic symptom cluster research, the objectives of this review are to examine the statistical methods that have been used to quantify and/or model the dynamic nature of symptom clustering, the methodological issues associated with those methods, and the statistical modeling techniques for the underlying mechanisms of symptom clustering. RECENT FINDINGS: Correlation, factor analysis, principal component analysis, and cluster analysis are analytical methods to identify symptom clusters and/or to examine the influence of symptom clusters on patient outcomes. More recent techniques include latent variable methods, such as latent profile analysis, to examine the phenotypes of symptom cluster experience and growth modeling to examine the longitudinal nature of symptom cluster experience. Future endeavors include an investigation of the underlying mechanisms of symptom clustering using longitudinal data analysis. The methodological issues include the domain of the symptoms, measurement errors, stability of the solution within the data, measurement timing, and sample size. SUMMARY: Each method has unique strengths and weaknesses, and the method choice should be driven by the aims and research questions of a given study.