Pivotal Advance: Eosinophil infiltration of solid tumors is an early and persistent inflammatory host response

Tumor-associated eosinophilia has been observed in numerous human cancers and several tumor models in animals; however, the details surrounding this eosinophilia remain largely undefined and anecdotal. We used a B16-F10 melanoma cell injection model to demonstrate that eosinophil infiltration of tumors occurred from the earliest palpable stages with significant accumulations only in the necrotic and capsule regions. Furthermore, the presence of diffuse extracellular matrix staining for eosinophil major basic protein was restricted to the necrotic areas of tumors, indicating that eosinophil degranulation was limited to this region. Antibody-mediated depletion of CD4+ T cells and adoptive transfer of eosinophils suggested, respectively, that the accumulation of eosinophils is not associated with T helper cell type 2-dependent immune responses and that recruitment is a dynamic, ongoing process, occurring throughout tumor growth. Ex vivo migration studies have identified what appears to be a novel chemotactic factor(s) released by stressed/dying melanoma cells, suggesting that the accumulation of eosinophils in tumors occurs, in part, through a unique mechanism dependent on a signal(s) released from areas of necrosis. Collectively, these studies demonstrate that the infiltration of tumors by eosinophils is an early and persistent response that is spatial-restricted. It is more important that these data also show that the mechanism(s) that elicit this host response occur, independent of immune surveillance, suggesting that eosinophils are part of an early inflammatory reaction at the site of tumorigenesis. © Society for Leukocyte Biology

Prognostic value of splenectomy and lymph-node dissection during gastric cancer resection

Gastric carcinoma is the second most common cause of digestive tumour-related death in Europe, North America and Asia. Today, the gold standard of treatment is still surgery, but outcomes to date are unsatisfactory. The Japanese Society for Research in Gastric Cancer (JSRGC) recommends the routine execution of splenectomy during gastrectomy. This recommendation is contested by western Authors because of increased morbidity and mortality without any real advantage in terms of survival. Patients treated for gastric cancer in our department between 1993 and 2002 were selected for this study. The 132 patients recruited were divided into two groups: a) those treated for gastric cancer without splenectomy; and b) those in whom splenectomy was performed in conjunction with gastrectomy. We analysed: the extent of lymph node dissection, the execution of the splenectomy, and the prognostic importance of factors relating to the patient, tumour and surgeon. Splenectomy was not associated with any increase in morbidity. Complications, especially of the septic type, and perioperative mortality were similar in both groups, and the same was true of survival at both 3 and 5 years. In our opinion, splenectomy should not be routinely combined with surgery for gastric cancer but could be considered for T3-T4 neoplasms or those localized in the upper two thirds of the stomach