Thrombocytosis in patients with tumors producing colony-stimulating factor

We investigated the cause of thrombocytosis in 14 patients with tumors producing colony-stimulating factor (CSF). Of the 14 patients, 10 had tumors producing granulocyte-CSF (G-CSF) and 4 had tumors producing granulocyte-macro-phage-CSF (GM-CSF). Thrombocytosis of greater than 400 x 109/L was noted in 8 of 10 patients with G-CSF-producing tumors and all 4 patients with GM-CSF-producing tumors. Median peak platelet counts were, respectively, 511 x 109/L (range, 384 to 694 x log /L) and 579 x 109/L (range, 526 to 910 x lo9 /L) in patients with tumors producing G-CSF and GM-CSF. In most patients, thrombocytosis declined towards the terminal stage. High interleukin-1 (IL-1) and IL-6 levels were found in addition to CSFs in the plasma or culture UMORS producing colony-stimulating factor (CSF) T are characterized by marked leukocytosis in the host and constitutive CSF production by the tumor cells.&apos