Clinical Subgroups of a Psychoneurologic Symptom Cluster in Women Receiving Treatment for Breast Cancer: A Secondary Analysis

Purpose/Objectives: To investigate clinical subgroups using an empirically identified psychoneurologic symptom cluster (depressed mood, cognitive disturbance, fatigue, insomnia, and pain) and to examine the differences among subgroups in the selected demographic and clinical variables, as well as in patient outcome (i.e., functional performance).

Design: Secondary analysis.

Setting: A university health science center in Salt Lake City, UT, and a National Cancer Institute-designated comprehensive cancer center in Philadelphia, PA.

Sample: 282 patients with breast cancer undergoing chemotherapy or radiotherapy.

Methods: Cluster analyses were conducted to identify subgroups. Multinomial logistic regression and one-way analyses of variance were used to examine the differences among subgroups.

Main Research Variables: Depressed mood, cognitive disturbance, fatigue, insomnia, pain, and functional performance.

Findings: Patients were classified into four distinct subgroups based on their symptom cluster experience: all low symptom, high fatigue and low pain, high pain, and all high symptom. Such patient classification patterns were consistent across the treatment trajectory, although group memberships were inconsistent. After initiating treatment, two additional subgroups emerged: high depressed mood and cognitive disturbance, and high fatigue and insomnia. Subgroups differed in physical performance status at baseline, symptom burden, and treatment modality in a relatively consistent pattern across time points. Patients in the all-high-symptom subgroup experienced the most serious limitations in activities across all time points.

Conclusions: Patient subgroups exist that share the unique experience of psychoneurologic symptoms.

Implications for Nursing: Findings are useful to determine who needs more intensive symptom management during cancer treatment. Future studies should examine whether specific symptom management strategies are more efficient for certain subgroups.