Stability of Symptom Clusters in Patients With Breast Cancer Receiving Chemotherapy

Context

Patients with breast cancer who undergo chemotherapy (CTX) experience between 10 and 32 concurrent symptoms. An evaluation of how these symptoms cluster together and how these symptom clusters change over time may provide insights into how to treat these multiple co-occurring symptoms.

Objectives

The purposes of this study were to determine the occurrence rates and severity ratings for 38 common symptoms, evaluate for differences in the number and types of symptom clusters, and evaluate for changes over time in these symptom clusters (i.e., before CTX, the week after CTX, and two weeks after CTX).

Methods

At each of the assessments, a modified version of the Memorial Symptom Assessment Scale was used to assess the occurrence and severity of the 38 symptoms. Exploratory factor analyses were used to extract the symptom clusters.

Results

Although across the two symptom dimensions (i.e., occurrence and severity) and the three assessments, eight distinct symptom clusters were identified, only five were relatively stable across both dimensions and across time (i.e., psychological, hormonal, nutritional, gastrointestinal, and epithelial). Two of the additional clusters varied by time but not by symptom dimension (i.e., sickness behavior and weight change). The CTX neuropathy cluster was identified only at the assessment performed in the week after CTX.

Conclusion

These findings provide insights into the most common symptom clusters in patients undergoing CTX for breast cancer. In addition, the most common symptoms within each cluster appear to be relatively stable across the two dimensions, as well as across time.