Objectives: The aim of this study was to investigate the clinical implications and underlying mechanism of tumor-related-leukocytosis (TRL) in cervical cancer. Methods: The clinical data of cervical cancer patients who were treated with definitive radiotherapy were analyzed to investigate the association between TRL and treatment outcome in retrospective and prospective settings. Clinical samples, cervical cancer cell lines, and a mouse model of cervical cancer were employed to examine the mechanisms responsible for TRL in cervical cancer, focusing on the myeloid-derived suppressor cell (MDSC) and tumor-derived granulocyte colony-stimulating factor(G-CSF). Results: TRL was significantly associated with shorter survival. The TRL-positive patients displayed upregulated tumor G-CSF expression and elevated serum G-CSF levels and increased MDSC frequencies in the blood compared with the TRL-negative patients. In vitro and in vivo investigations revealed that tumor-derived G-CSF is involved in the underlying causative mechanism of TRL and that the increase in the number of MDSC induced by tumor-derived G-CSF is responsible for the rapidly progressive nature of TRL-positive cervical cancer. The administration of anti-Gr-1 antibody or the depletion of MDSC by splenectomy significantly inhibited tumor growth in TRL-positive cervical cancer. Conclusion: TRL is an indicator of a poor prognosis in cervical cancer patients treated with definitive radiotherapy. MDSC induced by tumor-derived G-CSF is responsible for the rapidly progressive nature of TRL-positive cervical cancer. MDSC-targeting treatments might have therapeutic potential in TRL-positive cervical cancer.

Note: This abstract was not presented at the meeting.

Citation Format: Yuri Matsumoto, Mahiru Kawano, Tomoyuki Sasano, Seiji Mabuchi. MDSC targeting therapy for uterine cervical cancer displaying TRL. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1103. doi:10.1158/1538-7445.AM2014-1103