Background: In 1983, Pretlow et al. reported one classical study of the prognostic influence of eosinophil infiltration in human colon carcinoma. Since then, very few reports have analyzed this supposed prognostic influence in this type of tumor, although there have been several reports of other types of tumors with different results. Eosinophils seem to play a central role in the immunologic defense against tumors; their activity can be induced through immunotherapy with interleukin in cases that are unresponsive to conventional therapies.
Methods: To analyze the prognostic influence of eosinophils in colorectal carcinoma, the authors selected 126 patients with this type of tumor treated only with curative surgery and followed for a minimal period of 5 years. They divided these patients into 4 categories according to the number of eosinophils per high-power field (400x): 0 (Grade 1), 1-9 (Grade 2), 10-50 (Grade 3), and more than 50 (Grade 4).
Results: The results of this series confirm that high eosinophil counts are associated with a significantly better prognosis. In multivariate analysis, this factor was independent from staging, vascularization, p53 expression, and histologic grade.
Conclusions: Eosinophil count served as a significant independent favorable prognosticator in colorectal carcinoma patients.
Copyright 2000 American Cancer Society.