The novel cytotoxicity of neutrophils in the peripheral blood of patients with breast cancer versus healthy women.

e21055 Background: Using murine mammary tumor models, recent research conducted by our laboratory at the Sloan-Kettering Institute indicates that select neutrophils are mobilized and entrained by a primary breast tumor and uniquely have the capacity to inhibit metastatic seeding in the lung (Granot Z et al. unpublished). We sought to determine whether entrainment of cytotoxic neutrophils also occurs in blood samples from women with newly diagnosed breast cancer as contrasted to those garnered from healthy women. Methods: Subjects were 14 newly diagnosed pre-operative breast cancer patients without evidence of metastatic disease, 9 healthy female volunteers with no history of any cancer and 2 patients with newly diagnosed DCIS. Neutrophils were purified from the blood samples. Cytotoxicity was evaluated by incubating isolated neutrophils with luciferase labeled MDA-MB-231 cells. Luciferase activity, as a reflection of % cell kill, was measured using a Bio-Tek microplate luminescence reader. Results: Signif...