Fatigue, dyspnea, and cough comprise a persistent symptom cluster up to five years after diagnosis with lung cancer

Abstract

Context: Aggregates of concurrent symptoms, known as symptom clusters (SxCls), have been described in predominantly cross-sectional samples of lung cancer (LC) patients undergoing treatment.

Objectives: The objective of this study was to delineate SxCls in LC survivors up to five years after diagnosis, investigate their stability over time, and identify determinants of SxCl development and resolution.

Methods: A sensitivity approach involving multiple exploratory and confirmatory analyses was applied to an eight-year prospective cohort study that annually assessed 2405 patients with LC for symptom burden with the Lung Cancer Symptom Scale and Linear Analogue Self-Assessment.

Results: A single robust SxCl of fatigue, cough, and dyspnea was identified in 14.6%, 12.9%, 14.1%, 14.6%, and 15.4% of participants at Years 1-5 after diagnosis, respectively. Participants with the SxCl (SxCl (+)) were more likely to die than those without it; but this tendency diminished over time. SxCl persistence varied, with ≥40% of surviving patients annually transitioning to or from the SxCl(+) state until Year 4, after which the SxCl became increasingly stable. The SxCl was more likely to develop among male survivors who underwent surgery, received radiation, and were current smokers.

Conclusion: A single SxCl comprising dyspnea, fatigue, and cough has a stable prevalence among LC survivors up to five years after diagnosis but is not stable among individuals. Initially, after diagnosis, the SxCl is associated with a greater risk of death; however, after Year 2, the SxCl becomes increasingly stable and provides a marker for parenchymal lung injury.

Figure 1

Dendrogram of <1 cluster analysis.

Figure 2

Cumulative scree plots for factor analyses of data from years <1 through 5.

Figure 3

Latent variable structure derived from the modeled data.

Figure 4

Frequencies of transitions between symptom cluster-defined states and death over the first five years following lung cancer diagnosis. SxCl = symptom cluster.

Figure 5

Alterations over time first five years following lung cancer diagnosis in the probability of dying and transitioning between symptom cluster-defined states. SxCl = symptom cluster.