Symptom Clusters in Advanced Cancer Patients: An Empirical Comparison of Statistical Methods and the Impact on Quality of Life

Abstract

Purpose: To investigate the consistency of symptom cluster composition in advanced cancer patients using different statistical methodologies for all patients across five primary cancer sites, and to examine which clusters predict functional status, a global assessment of health and global quality of life.Methods: Principal components analysis and exploratory factor analysis (with different rotation and factor selection methods) and hierarchical cluster analysis (with different linkage and similarity measures) were used on a dataset of 1562 advanced cancer patients who completed the EORTC QLQ-C30.Results: Four clusters consistently formed for many of the methods and cancer sites: tenseworry-irritable-depressed (emotional cluster); fatigue-pain; nausea-vomiting; and concentrationmemory (cognitive cluster). The emotional cluster was a stronger predictor of overall quality of life than the other clusters. Fatigue-pain was a stronger predictor of overall health than the other clusters. The cognitive cluster and fatigue-pain predicted physical functioning, role functioning, and social functioning. Conclusions:The four identified symptom clusters were consistent across statistical methods and cancer types, although there were some noteworthy differences. Statistical derivation of symptom clusters is in need of greater methodological guidance. A psychosocial pathway in the management of symptom clusters may improve quality of life. Biological mechanisms underpinning symptom clusters need to be delineated by future research. A framework for evidence-based screening, assessment, treatment, and follow-up of symptom clusters in advanced cancer is essential.Statistical methods for symptom clusters in advanced cancer

Characteristics associated with inter-individual differences in the trajectories of self-reported attentional function in oncology outpatients receiving chemotherapy

“…Our findings are consistent with data from several studies [31,40,41], and a systematic review [29], that found that increases in physical fatigue in oncology patients were associated with decrements in cognitive function. This association may be explained by the fact that recent evidence suggests that cancer and its treatments trigger inflammatory processes that contribute to increased levels of physical fatigue and cognitive dysfunction in oncology patients [31].…”

“…Therefore, our findings regarding changes in attentional function over time, as well as the characteristics associated with decrements in attentional function warrant confirmation using objective measures of various components of cognitive function. Although our findings suggest that a number of characteristics are associated with decrements in attentional function, future studies need to consider the impact of multiple co-occurring symptoms or symptoms clusters on attentional function [41–43]. …”

The relationship between pro-inflammatory cytokines and pain, appetite and fatigue in patients with advanced cancer

“…Fatigue is commonly described in symptom clusters with pain [40, 41], and indeed the primary trial was a pain intervention trial. Our results showed that pain intensity was associated with fatigue, r s = .38 ( p < .01) (results not tabulated).…”

Identification of symptom clusters in cancer patients at palliative care clinic

“…[14] Pain detraction is considered to be most important symptom impact on quality of life. [15] It is reported to be more severe during the terminal period with an incidence of 70%–90%. [1617] The coexistence of pain with symptoms such as feeling nervous, worrying, and feeling irritable is not surprising.…”