Jun Sakata

Efficacy of glypican-3-derived peptide vaccine therapy on the survival of patients with refractory ovarian clear cell carcinoma

ABSTRACT Compared with other epithelial ovarian carcinoma subtypes, ovarian clear cell carcinoma (OCCC) has been recognized to show chemoresistance. Therefore, new treatment modalities are required for patients with OCCC that is refractory to chemotherapy. The carcinoembryonic antigen glypican-3 (GPC3) is expressed by approximately half of OCCC and is a promising immunotherapeutic target. The purpose of this study was to evaluate the effect of GPC3 peptide vaccine against refractory OCCC patients. We conducted a phase II trial with a GPC3-derived peptide vaccine in OCCC patients. Immunological responses were analyzed by ex vivo IFNγ ELISPOT assay. We also evaluated control subjects, who received best supportive care without vaccinations during the same period. Thirty-two patients with refractory OCCC were enrolled between July 2010 and September 2015, and underwent GPC3 peptide vaccination. Fifteen patients were vaccinated less than six times because their general condition progressively deteriorated, and 17 patients were vaccinated at least six times. Three patients showed a partial response as the best overall response. The GPC3 peptide vaccine induced a GPC3-specific CTL response in 15 out of 24 patients who had PBMCs collected three times or more. The prognosis of palliative care patients without GPC3 peptide vaccinations was significantly poorer than that of those with GPC3 peptide vaccinations (post cancer-treatment survival: p = 0.002). Although the disease control rate was not high, our results suggest that GPC3 peptide vaccinations may hold a significant impact to prolong survival of patients with refractory OCCC, allowing them to maintain quality of life with no serious toxicities.

A novel mechanism of neovascularization in peritoneal dissemination via cancer-associated mesothelial cells affected by TGF-β derived from ovarian cancer

Epithelial ovarian cancer (EOC) is believed to cause peritoneum dissemination through microenvironmental cell‑to-cell communication between the tumor and mesothelium, leading to the further acquisition of progressive and metastatic potentials. In the present study, we aimed to determine the role of cancer-associated mesothelial cells (CAMCs) in the promotion of tumor neovascularization and vascular permeability via enhanced vascular endothelial growth factor (VEGF) production. We examined whether a characteristic morphological change in human peritoneal mesothelial cells (HPMCs) was observed in the presence of malignant ascites and tumor-derived TGF-β. We focused on the enhanced production of VEGF in CAMCs and its crucial role in endothelial migration and tube formation. Normal HPMCs showed an epithelial morphology with a cobblestone appearance. When HPMCs were co-cultured with malignant ascites from patients with advanced EOC, a dramatic morphologic change was noted from an epithelioid pattern to an α-SMA-positive fibroblastic, mesenchymal pattern. Additionally, we found that EOC-derived TGF-β induced typical EMT-like morphological alteration in HPMCs, which was associated with CAMCs. We further discovered that CAMCs play a crucial role in the enhanced migration and tube formation of endothelial cells by the promotion of VEGF production. In conclusion, our findings indicate the possible involvement of CAMCs in the neovascularization of EOC and enhancement of vascular permeability, resulting in the formation of malignant ascites. The novel mechanism of CAMCs as a facilitator of EOC progression is displayed by microenvironmental cell-to-cell communication between EOC and the mesothelium.

Clinical significance and predicting indicators of post‐cancer‐treatment survival in terminally ill patients with ovarian cancer

Women with ovarian cancer (OC) often experience relapse and receive further repetitive chemotherapy. The objective of this study was to overview the remaining survival time after the final chemotherapy and to examine influential clinicopathologic indicators in those patients.

KIF20A expression as a prognostic indicator and its possible involvement in the proliferation of ovarian clear‑cell carcinoma cells

Kinesin family member 20A (KIF20A), which is involved in cytokinesis and intracellular transportation, has been recently reported to be upregulated in several malignancies and may contribute to chemotherapeutic resistance. We examined the distribution and expression of KIF20A in clear-cell carcinoma (CCC) of the ovary to elucidate its clinical significance and molecular mechanism. Paraffin sections from ovarian CCC tissues (N=43) were immunostained with KIF20A antibody, and the staining intensities were semi-quantitatively evaluated. Furthermore, we investigated whether silencing of KIF20A contributes to the proliferation-inhibitory potential using CCC cells. During the observational period, 18 patients (41.9%) developed recurrence. The median time to recurrence was 11.5 months. Patients in the high KIF20A expression group showed poorer progression-free survival (PFS) and overall survival (OS) than those in the low expression group (P=0.0443 and P=0.0478, respectively). In multivariable analyses, KIF20A expression was also a significantly independent indicator of PFS and a marginally significant indicator of OS [PFS: HR (high vs. low), 5.488; 95% CI, 1.410–24.772 (P=0.0136); OS: HR, 2.835; 95% CI, 0.854–11.035, (P=0.0897)]. In in vitro studies, the ovarian CCC cell proliferation was significantly decreased by KIF20A silencing or in the presence of KIF20A inhibitor in CCC cells. Cell cycle G2/M arrest and a higher apoptosis-induced fraction were more frequently observed in si-KIF20A-transfected CCC cells than in the control cells. Although the present study was preliminary, these data indicate the possible involvement of KIF20A in the proliferation of CCC, suggesting that targeting this molecule may contribute to reversing the malignant potential consequently affecting the oncologic outcome of CCC patients.

The upregulated expression of vascular endothelial growth factor in surgically treated patients with recurrent/radioresistant cervical cancer of the uterus

Vascular endothelial growth factor (VEGF) inhibitors have been utilized for the treatment against advanced or recurrent cervical carcinoma as a novel therapeutic modality. However, the expression level of VEGF in post-radiotherapy relapsed/persistent cervical cancer remains to be elucidated. The aim of the present study was to investigate the expression of VEGF and associated molecules using tumor samples from patients with post-radiotherapy relapsed/persistent cervical cancer. From a database of 826 patients who were treated at our institution between 2003 and 2015, eight patients with post-radiotherapy relapsed/persistent cervical cancer were identified, and 20 patients who underwent initial surgery alone were used as a control. Using samples from these patients, the expression levels of VEGF-A, VEGF receptor-1 (VEGFR-1) and hypoxia inducible factor-1α (HIF-1α) were immunohistochemically categorized as negative or weakly, moderately, or strongly positive according to the size of the staining area, and intensity. In carcinoma cells, the expression levels of VEGF-A, VEGFR-1 and HIF-1α were significantly higher in post-radiotherapy relapsed/persistent cervical cancer compared with control patients (P=0.0003, 0.0003, and 0.0001, respectively). In stroma cells, similar tendencies with statistical significance were observed (P=0.0014 and P<0.0001, respectively). In addition, the expression levels of VEGF-A and VEGFR-1 in carcinoma cells were significantly correlated with each other (P<0.0001). A significantly higher expression of VEGF was identified in post-radiotherapy relapsed/persistent cervical cancer compared with typical specimens from cervical cancer. The findings provide a novel insight into the clinical treatment for recurrent/persistent cervical cancer using a VEGF antagonist.

Secondary cytoreductive surgery potentially improves the oncological outcomes of patients with recurrent uterine sarcomas

Uterine sarcomas are some of the most malignant and aggressive tumor types among the gynecologic malignancies, and they are associated with a high rate of recurrence and a poor prognosis. Due to their rarity and diversity, the optimal treatment for recurrent uterine sarcomas has not yet been elucidated. The aim of the present study was to investigate the potential of secondary cytoreductive surgery (SCS) for patients with recurrent uterine sarcomas. A total of 18 patients with recurrent uterine sarcomas were retrospectively identified at the Department of Obstetrics and Gynecology, Nagoya University (Nagoya, Japan) between January 2002 and December 2015. This included 8 patients with leiomyosarcoma, 6 with carcinosarcoma, 3 with endometrial stromal sarcoma and 1 with adenosarcoma. All patients underwent primary debulking surgery as the initial treatment. In summary, 9 patients were treated with SCS when they experienced their first recurrence, and the other 9 patients were treated with non-SCS methods, including chemotherapy or radiotherapy. In the SCS group, 5/9 patients had confined pelvic recurrences, 3 patients had extra-pelvic diseases, including pulmonary metastasis, and one patient had intra- and extra-pelvic recurrence. The 3-year overall survival (OS) rates were 77.8 and 11.1% in the SCS and non-SCS groups, respectively. The patients who underwent SCS experienced a significantly longer OS time compared with those in the non-SCS group (P=0.006). In addition, the disease-free survival after second-line therapy was significantly longer in the SCS group than in the non-SCS group (P=0.0496). These findings suggest that resection of recurrent uterine sarcomas may be beneficial for the improvement of patient survival. Prospective studies with sufficient statistical power are warranted for further evaluation of the effect of SCS.

Efficacy of medroxyprogesterone acetate treatment and retreatment for atypical endometrial hyperplasia and endometrial cancer

Medroxyprogesterone acetate (MPA) is used to preserve fertility in patients with Grade 1 endometrial cancer without myometrial invasion (G1EA) and those with atypical endometrial hyperplasia (AEH). However, the efficacy of retreatment with MPA has not been sufficiently established for patients who experience recurrence but wish to retain their fertility. This study aimed to show the effectiveness of MPA treatment and retreatment for AEH and G1EA.

Impact of positive ZEB1 expression in patients with epithelial ovarian carcinoma as an oncologic outcome‑predicting indicator

Several previous studies have revealed that the expression of zinc finger E-box binding homeobox 1 (ZEB1) in solid malignancies has an important significance on the clinical outcome of patients. However, the association between ZEB1 expression and survival in patients with epithelial ovarian carcinoma (EOC) remains unclear. The objective of the present study was to examine the extent of ZEB1 expression in EOC using immunohistochemical staining and investigate its association with patient outcome. A total of 40 patients with EOC initially treated with cytoreductive surgery and systematic chemotherapy were enrolled. ZEB1 expression was immunohistochemically categorized as negative, weak, moderate and strong according to the size of the staining area, and intensity. Subsequently, the associations between ZEB1 expression and recurrence/progression-free survival (RFS) rate were examined. The median age of patients in the current study was 54 years old (range, 22-72 years old). Among these patients, 15 (37.5%) exhibited International Federation of Gynecology and Obstetrics stage I disease, and 10 (25.0%), 13 (32.5%), and 2 (5%) had stage II, III, and IV disease, respectively. No patients with negative expression of ZEB1 experienced recurrence. In addition, ZEB1 expression was identified to be a significant predictor of a poorer RFS rate compared with negative expression (negative vs. weak, moderate and strong, P=0.0126). Furthermore, multivariate analyses revealed that moderate and strong ZEB1 expression levels were significant prognostic indicators of a poorer RFS rate in patients with EOC (hazard ratio, 2.265; 95% confidence interval, 1.072-8.021; P=0.0349). Confining analysis to patients with the clear-cell/mucinous histological type, those with moderate/strong ZEB1 expression demonstrated a significantly poorer RFS rate (P=0.0025). Positive ZEB1 expression may be an indicator to predict unfavorable RFS in patients with EOC.

A post-recurrence survival‑predicting indicator for cervical cancer from the analysis of 165 patients who developed recurrence

The aim of the present study was to estimate the post-recurrence survival (PRS) of patients with relapsed uterine cervical cancer (RUCC). In addition, clinicopathological indicators that influenced PRS were investigated. Between 1998 and 2014, of 740 patients with cervical cancer, 165 patients experienced recurrence (recurrence rate, 22.3%), and 83 patients succumbed to the disease within a median follow-up of 34.3 months. A total of 151 stage Ib-IV patients who experienced recurrence after initial treatment for cervical cancer at our institute were analyzed. Uni- and multivariate analyses were performed using the Kaplan Meier method, and Cox regression model. The median age was 55 years (range, 20-88 years). In all, 80 patients succumbed to the disease. The median PRS time of all the patients was 28.4 months. The 1-, 3-, and 5-year PRS rates of patients were 75.1, 41.9, and 32.1%, respectively. In addition, the median survival period in patients who had received surgery as an initial treatment was significantly longer compared with that in patients who had not previously undergone surgery (36.7 vs. 23.3 months, respectively; P=0.0338). Following the univariate analysis, the median PRS in patients with in- and out-field recurrence was 12.6, and 45.9 months, respectively (P<0.0001). Furthermore, in the multivariable analysis, the recurrence site was a significant prognostic indicator of PRS [(In-field vs. Out-field); hazard ratio, 2.848; 95% confidence interval, 1.707-4.738; P<0.0001]. The long-term clinical outcome of patients with RUCC was poor. In particular, the in-field recurrence was identified to be associated with poor post-recurrence oncological outcome in patients with RUCC.

Oncologic and obstetric outcomes of early stage cervical cancer with abdominal radical trachelectomy: Single‐institution experience

Radical trachelectomy (RT) is a widely used fertility‐sparing treatment for patients with early cervical cancer (CCA). RT, however, is an investigational treatment, and its gynecological and obstetric efficacy are being investigated. We retrospectively assessed the efficacy of abdominal RT (ART) as a fertility‐sparing surgery.