Multiple symptoms in cancer patients present a complicated pattern of relationships. The current
challenge is to demonstrate convincingly the presence and utility of the construct of a symptom
cluster. Another challenge is to address confounding factors in the research design. The sampling
plan should control for cancer diagnosis and stage of disease as well as the type of cancer treatment.
Symptom measurement should be timed to the landmarks of the disease and treatment
process. Palliative management of symptoms should be accounted for. An ideal symptom cluster
measure includes parallel dimensions of each symptom within the same time frame using the
same method of scaling responses to questions. For intervention studies, intervention
development should focus on optimal management of all symptoms in the cluster. Analytic
methods can include factor analysis to determine the underlying structure of a group of
symptoms, cluster analysis to define group of individuals with similar symptom patterns, and
path models to examine direct and indirect relationships among symptoms. Continued study of
multiple symptoms will yield empirical confirmation or denial of the existence of symptom
clusters. It will also yield increased understanding of the patterns of association, interaction, and
synergy of multiple symptoms that produce specific clinical outcomes. Understanding the
complex symptom experience of oncology patients will provide a scientific basis and new
directions for clinical assessment and intervention.