Mahiru Kawano

Impact of histological subtype on survival of patients with surgically-treated stage IA2–IIB cervical cancer: Adenocarcinoma versus squamous cell carcinoma

OBJECTIVES To evaluate the significance of adenocarcinoma (AC) compared with squamous cell carcinoma (SCC) with regard to the survival of surgically-treated early stage cervical cancer patients. METHODS We retrospectively reviewed the medical records of 520 patients with FIGO stage IA2-IIB cervical cancer who were treated with radical hysterectomy with or without adjuvant radiotherapy between January 1998 and December 2008. The patients were classified according to (i) pathological risk factors (low-, intermediate-, or high-risk group) and (ii) adjuvant radiotherapy (concurrent chemoradiotherapy [CCRT group] or radiotherapy alone [RT group]). Survival outcomes were examined by Kaplan-Meier method and compared with Log-rank test. Multivariate analysis for disease-specific survival (DSS) was performed using Cox proportional hazards regression model to investigate the prognostic significance of histological subtype. RESULTS AC histology was associated with significantly decreased DSS compared with SCC histology in the intermediate- and high-risk groups (hazard ratio: 3.06 and 2.88, respectively, both P<0.05) while there was no survival difference in the low-risk group (P=0.1). Among patients who received any types of adjuvant radiotherapy, DSS of AC histology patients were significantly poorer than SCC histology. Multivariate analysis demonstrated AC histology to be an independent predictor of decreased DSS in both CCRT and RT groups. Moreover, pelvic nodal metastasis significantly predicted the poor survival of patients with AC histology who received CCRT in multivariate analysis CONCLUSIONS Adenocarcinoma is an independent prognostic indicator of poor survival in early stage cervical cancer patients with intermediate- and high-risk factors, regardless of the type of adjuvant radiotherapy after radical hysterectomy.

Uterine Cervical Cancer Displaying Tumor-Related Leukocytosis : A Distinct Clinical Entity With Radioresistant Feature

BACKGROUND Tumor-related leukocytosis (TRL) is occasionally found in patients with nonhematopoietic malignancies. We investigated the clinical implication of TRL and individualized treatment for TRL-positive cervical cancer, as well as the underlying biological mechanism. METHODS Clinical data from 258 cervical cancer patients treated with definitive radiotherapy were analyzed to investigate the association between TRL and treatment outcome. Clinical samples, cervical cancer cell lines, and a mouse model of cervical cancer were used to examine the mechanisms responsible for TRL in cervical cancer, focusing on the role of tumor-derived granulocyte colony-stimulating factor (G-CSF) and myeloid-derived suppressor cells (MDSCs). All statistical tests were two-sided. RESULTS TRL was statistically significantly associated with younger age (Wilcoxon rank sum test, P = .03), larger tumor size (Wilcoxon rank sum test, P = .006), advanced clinical stage (χ(2) test, P = .01), and shorter overall survival (Cox proportional hazard modeling and Wald tests, P < .001). Among cervical cancer patients, TRL was associated with upregulated tumor G-CSF expression (χ(2) test, P < .001), elevated serum G-CSF levels (Student t test, P = .03), larger spleens (Student t test, P = .045), and increased MDSC frequencies in the blood (Student t test, P < .001) compared with the TRL-negative patients. In vitro and in vivo experiments revealed that tumor-derived G-CSF was involved in the underlying causative mechanism of TRL and MDSCs induced by tumor-derived G-CSF are responsible for the rapidly progressive and radioresistant nature of TRL-positive cervical cancer. The administration of anti-Gr-1 neutralizing antibody or the depletion of MDSCs by splenectomy (n = 6 per group) inhibited tumor growth and enhanced radiosensitivity in TRL-positive cervical cancer xenografts (Wilcoxon rank sum test, P = .008 and P = .02, respectively). CONCLUSIONS TRL is associated with resistance to radiotherapy among cervical cancer patients, and MDSC-targeting treatments may have therapeutic potential in these patients.

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.

Potential Role of mTORC2 as a Therapeutic Target in Clear Cell Carcinoma of the Ovary

The goal of this study was to examine the role of mTOR complex 2 (mTORC2) as a therapeutic target in ovarian clear cell carcinoma (CCC), which is regarded as an aggressive, chemoresistant histologic subtype. Using tissue microarrays of 98 primary ovarian cancers [52 CCCs and 46 serous adenocarcinomas (SAC)], activation of mTORC2 was assessed by immunohistochemistry. Then, the growth-inhibitory effect of mTORC2-targeting therapy, as well as the role of mTORC2 signaling as a mechanism for acquired resistance to the mTOR complex 1 (mTORC1) inhibitor RAD001 in ovarian CCC, were examined using two pairs of RAD001-sensitive parental (RMG2 and HAC2) and RAD001-resistant CCC cell lines (RMG2-RR and HAC2-RR). mTORC2 was more frequently activated in CCCs than in SACs (71.2% vs. 45.7%). Simultaneous inhibition of mTORC1 and mTORC2 by AZD8055 markedly inhibited the proliferation of both RAD001-sensitive and -resistant cells in vitro. Treatment with RAD001 induced mTORC2-mediated AKT activation in RAD001-sensitive CCC cells. Moreover, increased activation of mTORC2–AKT signaling was observed in RAD001-resistant CCC cells compared with the respective parental cells. Inhibition of mTORC2 during RAD001 treatment enhanced the antitumor effect of RAD001 and prevented CCC cells from acquiring resistance to RAD001. In conclusion, mTORC2 is frequently activated, and can be a promising therapeutic target, in ovarian CCCs. Moreover, mTORC2-targeted therapy may be efficacious in a first-line setting as well as for second-line treatment of recurrent disease developing after RAD001-treatment. Mol Cancer Ther; 12(7); 1367–77. ©2013 AACR.

Elevated white blood cell count at the time of recurrence diagnosis is an indicator of short survival in patients with recurrent cervical cancer.

Objectives The aim of this study was to investigate the prognostic significance of elevated white blood cell (WBC) count at the time of the diagnosis of cervical cancer recurrence. Methods The baseline characteristics and outcome data of 219 patients who had a diagnosis of recurrent cervical cancer between April 1996 and September 2010 were collected and reviewed. Survival after recurrence was compared between the leukocytosis group (WBC ≥9000/&mgr;L) and the nonleukocytosis group (WBC <9000/&mgr;L). A Cox proportional hazards regression model was used to investigate the prognostic significance of elevated WBC count in patients with recurrent cervical cancer. Results The patients in the leukocytosis group showed significantly shorter disease-free interval (P = 0.0005) and more frequently had multiple recurrences (P = 0.0101) than those in the nonleukocytosis group. The median survival after recurrence of the patients with elevated WBC count was 9 months, which was significantly shorter than the 21 months observed in the patients without normal WBC count (log rank; P < 0.0001). Multivariate analyses revealed that clinical stage, tumor diameter, histology, an elevated WBC count (≥9000/&mgr;L), and an elevated neutrophil count (≥6500/&mgr;L) were significant prognostic factors in survival after recurrence. Conclusion The elevated WBC count at the time of the diagnosis of recurrence is an independent prognostic factor in patients with recurrent cervical cancer.

Preclinical Efficacy for AKT Targeting in Clear Cell Carcinoma of the Ovary

The aim of this study was to determine the role of AKT as a therapeutic target in ovarian clear cell carcinoma (CCC), an aggressive, chemoresistant histologic subtype of ovarian cancer. AKT activation was assessed by immunohistochemistry (IHC) using human tissue microarrays of primary ovarian cancers, composed of both CCC and serous adenocarcinoma (SAC). The growth-inhibitory effect of AKT-specific targeting by the small-molecule inhibitor, perifosine, was examined using ovarian CCC cell lines in vitro and in vivo. Finally, the activity of perifosine was examined using in CCC-derived tumors that had acquired resistance to anti-VEGF or chemotherapeutics such as bevacizumab or cisplatin, respectively. Interestingly, AKT was frequently activated both in early-stage and advanced-stage CCCs. Treatment of CCC cells with perifosine attenuated the activity of AKT–mTORC1 signaling, inhibited proliferation, and induced apoptosis. The effect of perifosine was more profound under conditions of high AKT activity compared with low AKT activity. Increased AKT activation and enhanced sensitivity to perifosine were observed in the context of cisplatin-resistant CCC. Treatment with perifosine concurrently with cisplatin significantly enhanced the antitumor effect of cisplatin. Moreover, perifosine showed significant antitumor activity in CCC-derived tumors that had acquired resistance to bevacizumab or cisplatin. Collectively, these data reveal that AKT is frequently activated in ovarian CCCs and is a promising therapeutic target in aggressive forms of ovarian cancer. Implications: AKT-targeted therapy has value in a first-line setting as well as a second-line treatment for recurrent disease developing after platinum-based chemotherapy or bevacizumab treatment. Mol Cancer Res; 13(4); 795–806. ©2014 AACR.

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.

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.

Combination treatment with trabectedin and irinotecan or topotecan has synergistic effects against ovarian clear cell carcinoma cells.

Objectives The objective of this study was to investigate the chemotherapeutic agents that produce the strongest synergistic effects when combined with trabectedin against ovarian clear cell carcinoma (CCC), which is regarded as an aggressive chemoresistant histological subtype. Methods Using 4 human CCC cell lines (RMG1, RMG2, KOC7C, and HAC2), the cytotoxicities of trabectedin, SN-38, topotecan, doxorubicin, cisplatin, and paclitaxel as single agents were first assessed using the MTS assay. Then, the cytotoxicities of combination treatments involving trabectedin and 1 of the other 4 agents were evaluated by isobologram analysis to examine whether these combinations displayed synergistic, additive, or antagonistic effects. The antitumor activities of the combination treatments were also examined using cisplatin-resistant and paclitaxel-resistant CCC sublines, which were derived from the parental CCC cells by continuously exposing them to cisplatin or paclitaxel. Finally, we determined the effect of everolimus on the antitumor efficacy of trabectedin-based combination chemotherapy. Results Concurrent exposure to trabectedin and SN-38 or topotecan resulted in synergistic interactions in all 4 CCC cell lines. Among the tested combinations, trabectedin plus SN-38 was the most effective cytotoxic regimen. The combination of trabectedin plus SN-38 also had strong synergistic effects on both the cisplatin-resistant and paclitaxel-resistant CCC cell lines. Treatment with everolimus significantly enhanced the antitumor activity of trabectedin plus SN-38 or topotecan. Conclusions Combination treatment with trabectedin and SN-38 displays the greatest cytotoxic effect against ovarian CCC. Our in vitro study provides the rationale for future clinical trials of trabectedin plus irinotecan with or without everolimus in patients with ovarian CCC in both the front-line chemotherapy setting and as a second-line treatment of recurrent CCC that had previously been treated with cisplatin or paclitaxel.

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.