Granulocyte colony-stimulating factor produced by bladder carcinoma of a patient with leukemoid reaction did not affect proliferation of the tumor cells.

Bladder carcinoma associated with leukemoid reaction, though it rarely occurs, is considered highly malignant and has proved to produce granulocyte colony-stimulating factor (G-CSF). Interest exists in whether G-CSF itself or G-CSF producing ability reflects the malignant potential of such a tumor, possibly through an autocrine mechanism. In a patient with invasive bladder carcinoma, we found that the tumor cells produced G-CSF responsible for a remarkable leucocytosis. However, we could not detect the rearrangement and amplification of the G-CSF gene nor the expression of G-CSF receptor in the tumor cells. Our immunohistological and molecular biological study failed to demonstrate a crucial role for G-CSF in mediating a growth advantage for the tumor.