Context: Research about clusters of symptoms in oncology is an emerging field of study. However, there is still conceptual confusion about clusters of symptoms and little agreement across studies.

Objectives: The aim of the present study was to explore clusters of symptoms over time in a large heterogeneous group of patients with cancer and thereby contribute to the conceptual and methodological debate in this research area.

Methods: A longitudinal design was used to assess symptoms in cancer patients over four time points during the first year after diagnosis using the Memorial Symptom Assessment Scale. The study recruited 143 patients from five U.K. cancer centers and provided 504 symptom assessments at the beginning of treatment and 3, 6, and 12 months later.

Results: Six symptom clusters were identified at the first assessment, which were maintained across the assessment points with slight variations. These included gastrointestinal, hand/foot, body image, respiratory, nutritional, and emotional symptom clusters. The behavior of the clusters over time highlighted the complexities of symptom cluster assessment and the dynamic relationships between symptoms. Frequency, severity, and distress from symptoms were significantly higher (up to 75% higher) in patients who experienced a cluster of symptoms than in the overall sample, suggesting that symptom assessments in unselected patients underestimate the symptom burden in subgroups of patients.

Conclusion: We propose attention to symptom clusters that are stable across time and include core or defining symptoms within the cluster, and we further discuss the usefulness and applicability of conceptual and methodological criteria used in this study for future symptom cluster research.