Aims:    Despite significant advances in the management of discrete symptoms, 40-61% of cancer patients report multiple symptoms during treatment. Unrelieved multiple symptoms are associated with reduced treatment compliance/completion, performance status and quality of life (QoL). Consequently, we examined the impact of multiple symptoms on overall QoL and physical/psychological health across treatment.

Methods: A longitudinal secondary analysis involving 200 cancer patients who underwent combined modality treatment.

Results: All patients reported multiple concurrent symptoms across treatment, with most experiencing at least 5. Severe symptoms included fatigue, sleep disturbance and role/social functioning impairment. Patients reporting high multiple concurrent symptoms experienced significantly worse overall QoL/physical health, cancer distress and depression across treatment, as did those who experienced high-symptom severity (.01≥p≤.06). Factor analyses of QoL scores at pre-/on-/post-treatment identified three recurrent symptom clusters of core or defining symptoms: physical-function related (physical/role/social functioning, fatigue); psychoneurological (emotional/cognitive functioning); and gastrointestinal (nausea/vomiting/appetite loss). Patients reporting high-symptom severity for each of these symptom clusters experienced significantly worse overall QoL/physical health (.001>p≤.024), but not cancer distress except for the psychoneurological symptom cluster (p<.001). Patients experiencing more severe psychoneurological or physical-function related cluster symptoms also reported significantly greater depression (p<.001).

Conclusions: This study confirmed that patients experience multiple symptoms concurrently across treatment, and that unrelieved multiple symptoms negatively impact QoL, physical and psychological outcomes. While traditional cancer treatments can induce new or exacerbate existing symptoms by damaging normal cells, targeted therapies ± traditional chemotherapy/radiotherapy are still quite capable of producing dose-limiting toxicities. Patients rarely present with a single symptom, which likely explains why single-symptom management approaches do not necessarily improve QoL. Symptom management/QoL research must investigate beyond individual symptoms by examining symptom clusters. Gaining greater insight into the relationships between core symptoms within a cluster will allow clinicians to implement more effective interventions to alleviate multiple symptoms, and improve patient outcomes including QoL. To this end, further longitudinal studies involving homogeneous/heterogeneous cancer populations are needed to clarify the clustering of symptoms.