Eosinophils in Cancer: Favourable or Unfavourable?

Abstract

Eosinophils are granulocytic leukocytes residing in blood and tissues in the lung, breast, gastrointestinal and reproductive systems. Eosinophilia is uncommon in healthy individuals, however, it is associated with allergies, helminth infections and some inflammatory states. Eosinophilia has also been observed in cancer, including colorectal, breast, ovarian, cervical, oral squamous, Hodgkin's lymphoma and prostate cancer. Whether an increase in eosinophils leading to a favourable or unfavourable prognosis still remains controversial and depends on many factors including the type of cancer. Eosinophil infiltration is considered unfavourable in Hodgkin's lymphoma, conversely it has also been linked to a favourable prognosis in colorectal, breast and prostate cancers. Eosinophils secrete a variety of cytokines and factors including eosinophil cationic protein, eosinophil-derived neurotoxin, peroxidase and major basic protein which have either anti-tumor effects or stimulate tumor progression. Herein, we discuss the role of eosinophils in tumor immunity and propose mechanisms accounting for their functional differences in tumorigenesis.

Twelve-year survival and immune correlates in dendritic cell–vaccinated melanoma patients

“…86-91), but by enhancing the infiltration of CD8 + T cells via secretion of chemoattractants and normalizing tumor vessels, thus providing a mechanistic link to understanding why an increased eosinophil count may herald a better outcome (92). Of note is that tumor eosinophil infiltration has been described as favorable (e.g., in colon cancer) (93) or unfavorable (94). Its occurrence and relevance in human melanoma remain to be studied in more detail, but it is striking that Soiffer et al observed both blood eosinophilia and degranulating eosinophils in regressing melanoma metastases upon vaccination with GM-CSF-secreting autologous melanoma cells (95).…”

New Insights Into the Role of Tissue Eosinophils in the Progression of Colorectal Cancer: A Literature Review

“…25 In this context, TATE has been widely studied, as previously revised. 4,6,[26][27][28][29][30][31] In this study, we aimed at reviewing the prognostic value of TATE in CRC. In contrast to previous reviews, which summarized this topic in the context of wider subjects, 4,6,26,28,29,31 our review included a larger number of studies and provided more detailed information on TATE characterization and on the association between TATE and other clinicopathological features in CRC.…”

Eosinophils and Cancer – Mini Review

“…This role of macrophages in normal development also appears to be subverted by tumors of the mammary gland to promote the escape of the tumor cells from the local environment and enhance their rate of metastasis. These data emphasize the dual role of macrophages in the promotion of epithelial growth in normal and cancer states [15] Eosinophils are correlated to linked to a favourable prognosis in colorectal, breast and prostate cancers [16].…”

“…In other studies, certain types of lymphoid and solid tumors have been associated with the infiltration of eosinophils into cancerous tissues [16][17][18], particularly specific lymphomas and Hodgkin's disease. Although tumor-related eosinophilia was considered to be an epiphenomenon arising from the spontaneous elaboration of IL-5 from tumor cells, or overproduction of T cells during chemotherapy with IL-2 [19], there is evidence of eosinophil activation as a result of IL-2 anticancer therapy [20,21].…”