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.

Context: Patients with lung cancer who undergo chemotherapy (CTX) experience multiple 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 cooccurring symptoms. Objectives: The purposes of this study, in a sample of lung cancer patients (n=145) who were receiving chemotherapy (CTX) were to evaluate for differences in the number and types of symptom clusters at three time points (i.e., before CTX, the week after CTX, and two weeks after CTX) using ratings of symptom occurrence and severity and to evaluate for changes in these symptom clusters over time. Methods: At each of the three 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: Across the two symptom dimensions (i.e., occurrence and severity) and the three assessments, six distinct symptom clusters were identified. However, only three of these clusters were relatively stable across both dimensions and across time (i.e., lung cancer specific, psychological, nutritional). Two additional clusters varied by time but not by symptom dimension (i.e., epithelial/gastrointestinal, epithelial). A sickness behavior cluster was identified at each assessment with the exception of the week before CTX using the severity dimension. Conclusion: These findings provide insights into the most common symptom clusters in patients undergoing CTX for lung cancer. The most common symptoms within each cluster appear to be relatively stable across the two dimensions, as well as across time.

Purpose One of the unanswered questions in symptom clusters research is whether the number and types of symptom clusters vary based on the dimension of the symptom experience used to create the clusters. Given that patients with breast cancer receiving chemotherapy (CTX), report between 10 and 32 concurrent symptoms and studies of symptom clusters in these patients are limited, the purpose of this study, in breast cancer patients undergoing CTX (n=515), was to identify whether the number and types of symptom clusters differed based on whether symptom occurrence rates or symptom severity ratings were used to create the clusters. Methods A modified version of the Memorial Symptom Assessment Scale was used to assess for the occurrence and severity of 38 symptoms, one week after the administration of CTX. Exploratory factor analysis was used to extract the symptom clusters. Results Both the number and types of symptom clusters were similar using symptom occurrence rates or symptom severity ratings. Five symptom clusters were identified using symptom occurrence rates (i.e., psychological, hormonal, nutritional, gastrointestinal, epithelial). Six symptom clusters (i.e., psychological, hormonal, nutritional, gastrointestinal, epithelial, chemotherapy neuropathy) were identified using symptom severity ratings. Across the two dimensions, the specific symptoms within each of the symptom clusters were similar. Conclusions Identification of symptom clusters in patients with breast cancer may be useful in guiding symptom management interventions. Future studies are warranted to determine if symptom clusters remain stable over a cycle of CTX in patients with breast cancer.

Additional research is needed in oncology patients to address the assessment of symptom clusters, the specific nature of symptom clusters and whether symptom clusters change over time.

Preoperative breast pain in women with breast cancer may result from a number of causes. Previous work from our team found that breast pain occurred in 28.2% of women (n=398) who were about to undergo breast cancer surgery. The occurrence of preoperative breast pain was associated with a number of demographic and clinical characteristics, as well as variation in two cytokine genes. Given that ion channels regulate excitability of sensory neurons, we hypothesized that variations in potassium channel genes would be associated with preoperative breast pain in these patients. Therefore, in this study we evaluated for associations between single nucleotide polymorphisms and inferred haplotypes among 10 potassium channel genes and the occurrence of preoperative breast pain in patients scheduled to undergo breast cancer surgery. Multivariable logistic regression analyses were used to identify those genetic variations that were associated with the occurrence of preoperative breast pain while controlling for age and genomic estimates of and self-reported race/ethnicity. Variations in four potassium channel genes: 1) potassium voltage-gated channel, delayed rectifier, subfamily S, member 1 (KCNS1); 2) potassium inwardly-rectifying channel, subfamily J, member 3 (KCNJ3); 3) KCNJ6; and 4) potassium channel, subfamily K, member 9 (KCNK9) were associated with the occurrence of breast pain. Findings from this study warrant replication in an independent sample of women who report breast pain following one or more breast biopsies.