Katsumi Kozasa

The significance of G-CSF expression and myeloid-derived suppressor cells in the chemoresistance of uterine cervical cancer

Granulocyte-colony stimulating factor (G-CSF) producing malignant tumor has been reported to occur in various organs, and has been associated with poor clinical outcome. The aim of this study is to investigate the significance of tumor G-CSF expression in the chemosensitivity of uterine cervical cancer. The clinical data of recurrent or advanced cervical cancer patients who were treated with platinum-based chemotherapy were analyzed. Clinical samples, cervical cancer cell lines, and a mouse model of cervical cancer were employed to examine the mechanisms responsible for the development of chemoresistance in G-CSF-producing cervical cancer, focusing on myeloid-derived suppressor cells (MDSC). As a result, the tumor G-CSF expression was significantly associated with increased MDSC frequencies and compromised survival. In vitro and in vivo experiments demonstrated that the increased MDSC induced by tumor-derived G-CSF is involved in the development of chemoresistance. The depletion of MDSC via splenectomy or the administration of anti-Gr-1 antibody sensitized G-CSF-producing cervical cancer to cisplatin. In conclusion, tumor G-CSF expression is an indicator of an extremely poor prognosis in cervical cancer patients that are treated with chemotherapy. Combining MDSC-targeting treatments with current standard chemotherapies might have therapeutic efficacy as a treatment for G-CSF-producing cervical cancer.

Prognostic significance of systemic neutrophil and leukocyte alterations in surgically treated endometrial cancer patients: A monoinstitutional study

OBJECTIVE The aim of this study was to investigate the prognostic significance of an elevated neutrophil count at the time of the initial diagnosis in patients with surgically treated endometrial cancer. METHODS The baseline characteristics and outcome data of patients who were diagnosed with endometrial cancer between January 2000 and December 2010 were collected and retrospectively reviewed. The patients were separated into two groups according to their neutrophil counts. The clinicopathological characteristics and overall survival rates of the two groups were compared. A Cox proportional hazard regression model was used to investigate the prognostic significance of an elevated neutrophil count among patients with surgically treated endometrial cancer. RESULTS An elevated neutrophil count was found to be associated with an advanced clinical stage (P<0.0001), lymphovascular space involvement (P=0.0003), cervical involvement (P=0.0049), the proportion of patients that received adjuvant therapy (P=0.0020), elevated NLR (P<0.0001), and treatment failure (P<0.0001). Multivariate analyses demonstrated that age (hazard ratio (HR)=2.23, 95% confidence interval (95% CI)=1.30 to 3.91; P=0.0035), clinical stage (HR=4.72, 95% CI=2.61 to 8.90; P<0.0001), lymphovascular space involvement (HR=3.15, 95% CI=1.60 to 6.68; P=0.0007), an elevated neutrophil count (HR=2.76, 95% CI=1.43 to 5.03; P=0.0033), and an elevated white blood cell count (HR=2.79, 95% CI=1.50 to 4.96; P=0.0017) were significant predictors of survival. CONCLUSION The elevated neutrophil or leukocyte counts at the time of the initial diagnosis are independent prognostic factors in patients with surgically treated endometrial cancer.

Impact of histological subtype on survival in patients with locally advanced cervical cancer that were treated with definitive radiotherapy: adenocarcinoma/adenosquamous carcinoma versus squamous cell carcinoma

Objective To compare the survival outcomes of patients with cervical squamous cell carcinoma (SCC) and adenocarcinoma/adenosquamous carcinoma (AC/ASC) among patients with locally advanced cervical cancer that were treated with definitive radiotherapy. Methods The baseline characteristics and outcome data of patients with locally advanced cervical cancer who were treated with definitive radiotherapy between November 1993 and February 2014 were collected and retrospectively reviewed. A Cox proportional hazards regression model was used to investigate the prognostic significance of AC/ASC histology. Results The patients with AC/ASC of the cervix exhibited significantly shorter overall survival (OS) (p=0.004) and progression-free survival (PFS) (p=0.002) than the patients with SCC of the cervix. Multivariate analysis showed that AC/ASC histology was an independent negative prognostic factor for PFS. Among the patients who displayed AC/ASC histology, larger tumor size, older age, and incomplete response to radiotherapy were found to be independent prognostic factors. PFS was inversely associated with the number of poor prognostic factors the patients exhibited (the estimated 1-year PFS rates; 100.0%, 77.8%, 42.8%, 0.0% for 0, 1, 2, 3 factors, respectively). Conclusion Locally advanced cervical cancer patients with AC/ASC histology experience significantly worse survival outcomes than those with SCC. Further clinical studies are warranted to develop a concurrent chemoradiotherapy (CCRT) protocol that is specifically tailored to locally advanced cervical AC/ASC.

Preclinical Investigations of PM01183 (Lurbinectedin) as a Single Agent or in Combination with Other Anticancer Agents for Clear Cell Carcinoma of the Ovary

Objective The objective of this study was to evaluate the antitumor effects of lurbinectedin as a single agent or in combination with existing anticancer agents for clear cell carcinoma (CCC) of the ovary, which is regarded as an aggressive, chemoresistant, histological subtype. Methods Using human ovarian CCC cell lines, the antitumor effects of lurbinectedin, SN-38, doxorubicin, cisplatin, and paclitaxel as single agents were assessed using the MTS assay. Then, the antitumor effects of combination therapies involving lurbinectedin and 1 of the other 4 agents were evaluated using isobologram analysis to examine whether these combinations displayed synergistic effects. The antitumor activity of each treatment was also examined using cisplatin-resistant and paclitaxel-resistant CCC sublines. Finally, we determined the effects of mTORC1 inhibition on the antitumor activity of lurbinectedin-based chemotherapy. Results Lurbinectedin exhibited significant antitumor activity toward chemosensitive and chemoresistant CCC cells in vitro. An examination of mouse CCC cell xenografts revealed that lurbinectedin significantly inhibits tumor growth. Among the tested combinations, lurbinectedin plus SN-38 resulted in a significant synergistic effect. This combination also had strong synergistic effects on both the cisplatin-resistant and paclitaxel-resistant CCC cell lines. Everolimus significantly enhanced the antitumor activity of lurbinectedin-based chemotherapies. Conclusions Lurbinectedin, a new agent that targets active transcription, exhibits antitumor activity in CCC when used as a single agent and has synergistic antitumor effects when combined with irinotecan. Our results indicate that lurbinectedin is a promising agent for treating ovarian CCC, both as a first-line treatment and as a salvage treatment for recurrent lesions that develop after platinum-based or paclitaxel treatment.

Predictors of Survival in Patients With FIGO Stage IVB Cervical Cancer.

Objective The aim of this study was to identify prognostic factors and establish a model for predicting life expectancy in International Federation of Gynecology and Obstetrics stage IVB cervical cancer patients. Methods The baseline characteristics and outcome data of patients with stage IVB cervical cancer between May 1994 and October 2014 were collected and retrospectively reviewed. A Cox proportional hazards regression model was used to identify independent predictors of survival in stage IVB cervical cancer patients. Results A total of 107 patients were included in our database. The median overall survival (OS) period was 16 months. Multivariate analysis revealed that the metastatic site (hazards ratio, 3.09; 95% confidence interval, 1.94–4.88; P < 0.0001) and a white blood cell (WBC) count exceeding 10,000/&mgr;L (hazards ratio, 2.02; 95% confidence interval, 1.19–3.30; P = 0.0102) were significant prognostic factors in terms of OS. Patient survival was inversely correlated with the number of these prognostic factors possessed. When the patients were divided into 3 prognostic groups, the median OS of the patients with 0, 1, or 2 poor prognostic factors was 26, 12, and 7 months, respectively. Among the patients with WBC counts of less than 10,000/&mgr;L, treatment with radiotherapy resulted in improved survival compared with chemotherapy or palliative care alone. In contrast, radiotherapy had minimal effects on survival in patients with WBC counts of greater than 10,000/&mgr;L. Conclusions The metastatic site and an elevated WBC count are significant prognostic factors in patients with stage IVB cervical cancer. Our prognostic model composed of these 2 clinical variables might enable physicians to predict survival more accurately.

Prognostic Significance of Pretreatment Thrombocytosis in Cervical Cancer Patients Treated With Definitive Radiotherapy.

Objective The aim of this study was to investigate the prevalence and prognostic significance of an elevated platelet count at the time of the initial diagnosis in patients with cervical cancer who are treated with definitive radiotherapy. Methods The baseline characteristics and outcome data of cervical cancer patients who were treated with definitive radiotherapy between November 1993 and December 2011 were collected and retrospectively reviewed. The patients were separated into 2 groups according to their platelet counts. The clinicopathological characteristics and overall survival rates of the 2 groups were compared. A Cox proportional hazards regression model was used to investigate the prognostic significance of an elevated platelet count. Results An elevated platelet count was found to be associated with younger age (P = 0.0003), an advanced clinical stage (P < 0.0001), larger tumors (P = 0.0025), lower hemoglobin levels (P < 0.0001), and more frequent treatment failure (P = 0.0015). Multivariate analysis demonstrated that an advanced clinical stage (hazards ratio [HR], 2.93; 95% confidence interval [CI], 1.47–6.70; P = 0.0015), nonsquamous cell carcinoma histology (HR, 2.67; 95% CI, 1.52–4.42; P = 0.0011), larger tumors (HR, 3.86; 95% CI, 2.18–7.03; P < 0.0001), lower hemoglobin levels (HR, 1.99; 95% CI, 1.34–2.93; P = 0.0008), and an elevated platelet count (HR, 1.65; 95% CI, 1.03–2.56; P = 0.0395) were significant predictors of survival. Conclusions An elevated platelet count at the time of the initial diagnosis is an independent prognostic factor in cervical cancer patients who are treated with definitive radiotherapy.

The significance of lymphatic space invasion and its association with vascular endothelial growth factor-C expression in ovarian cancer

The aim of this study is to investigate the significance of lymphatic space invasion (LSI) and tumor VEGF-C expression in the lymphatic spread of ovarian cancer. By performing immunostaining using human ovarian cancer specimens, we first investigated the association between the extent of LSI and tumor VEGF-C expression, tumor lymphangiogenesis, or the lymphatic metastasis. Moreover, by performing in vitro and in vivo experiments, we elucidated the role of VEGF-C in tumor lymphangiogenesis and lymph node metastasis as well as its role as a therapeutic target in ovarian cancer. The presence of LSI was associated with lymph node metastasis in patients with ovarian cancer. VEGF-C overexpression was significantly associated with the increased LSI and LVD in ovarian cancer. VEGF-C stimulated the lymphangiogenesis in vitro, induced the new lymph vessel formation, and increased the lymph node metastasis in mice models of ovarian cancer. The attenuation of VEGF-C expression by the treatment with mTORC1 inhibitor significantly inhibited lymphangiogenesis, and decreased lymph node metastasis in mice models of ovarian cancer. The presence of LSI is an indicator of nodal metastasis and is associated with higher tumor VEGF-C expression and worse clinical outcome of ovarian cancer patients. VEGF-C plays a crucial role in tumor lymphangiogenesis and lymph node metastasis of ovarian cancer.

The Highly Metastatic Nature of Uterine Cervical/Endometrial Cancer Displaying Tumor-Related Leukocytosis: Clinical and Preclinical Investigations

Purpose: The aim of this study was to investigate the metastatic potential of uterine cervical and endometrial cancer displaying tumor-related leukocytosis (TRL). Experimental Design: Clinical data on uterine cervical (N = 732) and endometrial cancer (N = 900) were collected, and the metastatic potential of TRL-positive cancer was evaluated in univariate and multivariate analyses. Tumor and blood samples obtained from patients with cervical cancer, cervical cancer cell lines, and a mouse model of cervical cancer were used to examine the mechanisms underlying the highly metastatic nature of TRL-positive cancer, focusing on tumor-derived G-CSF and the myeloid-derived suppressor cell (MDSC)-mediated premetastatic niche. Results: Pretreatment TRL was significantly associated with visceral organ metastasis in patients with uterine cervical or endometrial cancer. The patients with TRL-positive cervical cancer displayed upregulated tumor G-CSF expression, elevated G-CSF levels, and increased MDSC frequencies in the peripheral blood compared with the TRL-negative patients. In vitro and in vivo investigations revealed that MDSCs produced in response to tumor-derived G-CSF are involved in premetastatic niche formation, which promotes visceral organ metastasis of TRL-positive cancer. The depletion of MDSCs attenuated this premetastatic niche formation and effectively inhibited the visceral organ metastasis of TRL-positive cancer. Conclusions: Uterine cervical/endometrial cancer displaying TRL is a distinct clinical entity with high metastatic potential. Tumor-derived G-CSF and the MDSC-mediated premetastatic niche are responsible for the highly metastatic nature of this type of cancer. MDSC-targeting therapy might represent a potential strategy for combating metastasis derived from TRL-positive uterine cancer. Clin Cancer Res; 24(16); 4018–29. ©2018 AACR.

Radical hysterectomy after radiotherapy for recurrent or persistent cervical cancer

To evaluate the safety and efficacy of radical hysterectomy after radiotherapy (RH‐AR) for recurrent or persistent cervical cancer.

PM01183 inhibits myeloid-derived suppressor cells in vitro and in vivo

AIM To evaluate the ability of PM01183 to eliminate myeloid-derived suppressor cells (MDSCs). MATERIALS & METHODS The effect of PM01183 on MDSCs, NK cells and CD8+ T cells was examined in vitro and in vivo. The mechanism by which PM01183 depletes MDSCs was also investigated. RESULTS PM01183 reduced the number of MDSCs by inducing apoptosis and attenuated the MDSC-mediated suppression of CD8+ T cells by inhibiting arginase-1 production, whereas no significant effect on CD8+ T or NK cells was noted. The inhibitory effect of PM01183 on MDSC was mediated by the attenuation of STAT3 phosphorylation. The inhibitory effect of PM01183 on MDSCs was greater than those of existing anticancer agents. CONCLUSION PM01183 exhibits strong inhibitory effects on MDSCs.