Abstract
A small subset of carcinomas of various origins are associated with high numbers of tumor-infiltrating neutrophils (TINs). Here, we examined the characteristics of non-small-cell pulmonary carcinomas with high numbers of TINs, and their relationship with lymph node (LN) metastasis. The study included 100 patients diagnosed and treated for primary pulmonary carcinoma at Showa University Northern Yokohama Hospital from 2011 to 2012. We histopathologically defined tumors with > 10 neutrophils per high-power field as neutrophilrich. Among the 100 patients, 40 were classed as having neutrophilrich pulmonary cancer (NRPC), and tissue samples from these patients were prepared for further examination. Comparison of the clinicopathological factors (age, gender, tumor size, histological type, and grade) in NRPC cases with or without LN metastasis showed that none of the above factors was significantly correlated with LN metastasis. Immunohistochemical analysis of two cytokines that play a major role in granulopoiesis, granulocyte-colony stimulating factor (G-CSF) and macrophage-CSF (M-CSF), revealed that the expression of M-CSF, but not G-CSF, was significantly correlated with LN metastasis. Furthermore, coexpression of M-CSF and the M-CSF receptor was significantly correlated with LN metastasis, but coexpression of G-CSF and the G-CSF receptor did not show such a correlation. These findings indicate that M-CSF-producing NRPCs show a significantly high lymph node metastasis potential.
