Considering recent inconsistent findings on ethnic differences in cancer pain experience, there is a need to clarify the association of ethnicity to cancer pain experience through diverse approaches. However, there currently exist only a small number of studies on ethnic differences in cancer pain experience in general, and few symptom cluster studies specifically related to ethnic differences in cancer pain experience. The purpose of this study was to cluster cancer patients who reported similar cancer pain experience, and to determine ethnic differences in the clusters.

This was a secondary analysis of the data from a larger Internet study on cancer pain experience of four major ethnic groups of cancer patients in the United States. Only 388 subjects who responded to the questions on cancer pain, cancer symptoms, and functional status were included for this secondary analysis. The data were analyzed using hierarchical cluster analysis and multinomial logistic analysis.

A three-cluster solution was adopted: 1) Cluster 1 with low pain, low symptoms, and high functional status, 2) Cluster 2 with moderate pain, low symptoms, and moderate functional staus, and 3) Cluster 3 with high pain, moderate symptoms, and low functional status. In Cluster 2, there were ethnic difference in the cancer pain and funtional status scores; Asian Americans reported lower pain scores than did other ethnic groups, and African Americans had higher funtional status scores than did other ethnic groups. In Cluster 3, there were ethnic difference in the symptom scores (p < 0.05); African Americans reported higher symptom scores than did whites.

The results of this study add an important piece of information on ethnic differences in symptom clusters. This study suggests further national scope studies on clustering multiethnic groups of cancer patients by cancer pain experience.