The expansion of tumor-associated neutrophils (TANs) was characterized in mice.
Effects of low-dose 5-FU, Bu, and Treo on TANs were determined.
TANs represent MDSCs/G-MDSCs in tumor-bearing mice.
5-FU and Treo, but not Bu, reduce the tumor size in tumor-bearing mice.
5-FU and Treo, but not Bu, attenuate the numbers of TANs, MDSCs and bone marrow myeloid cells in tumor-bearing mice.