Masashi Takano

Clear cell carcinoma of the ovary: a retrospective multicentre experience of 254 patients with complete surgical staging

A retrospective analysis was performed to evaluate the clinical characteristics and prognostic factors in the patients with clear cell carcinoma (CCC) of the ovary. After central pathological review and scanning of the medical records of nine Japanese institutions between 1992 and 2003, a total of 254 patients with CCC of the ovary were enrolled in the present study. Mean age was 52.4 years (range 23–73 years). Tumours were 13% (33/254) stage Ia, 36% (92/254) stage Ic, 13% (33/254) stage II, 30% (80/254) stage III, and 6% (16/254) stage IV. Five-year progression-free survival and overall survival was 84 and 88% in stage I, 57 and 70% in stage II, 25 and 33% in stage III and 0 and 0% in stage IV, respectively. Retroperitoneal lymph node metastasis was observed in 9% in pT1a tumours, 7% in pT1c tumours, 13% in pT2 tumours, and 58% in pT3 tumours, respectively. There was no survival benefit according to chemotherapeutic differences in the patients who received complete surgical staging procedures and conventional chemotherapy. Peritoneal cytological status was an independent prognostic factor in stage Ic patients (P=0.03) and only residual tumour diameter was an independent prognostic factor in stage III, IV patients (P=0.02). Our results suggest that cytoreductive surgery resulting in no residual tumour only could improve the prognosis of advanced CCC patients.

Loss of ARID1A protein expression occurs as an early event in ovarian clear-cell carcinoma development and frequently coexists with PIK3CA mutations

ARID1A is a recently identified tumor suppressor gene that is mutated in ∼50% of ovarian clear-cell carcinomas. This mutation is associated with loss of ARID1A protein expression as assessed by immunohistochemistry. The present study aimed at determining the timing of the loss of ARID1A protein expression during the development of ovarian clear-cell carcinoma and assessing its relevance in correlation to PIK3CA gene mutations. A total of 42 clear-cell carcinoma cases with adjacent putative precursor lesions (endometriosis-associated carcinoma cases (n=28) and (clear-cell) adenofibroma-associated carcinoma cases (n=14)) were selected and subjected to immunohistochemical analysis for ARID1A protein expression and direct genomic DNA sequencing of exons 9 and 20 of the PIK3CA gene. ARID1A immunoreactivity was deficient in 17 (61%) of the 28 endometriosis-associated carcinomas and 6 (43%) of the 14 adenofibroma-associated carcinomas. Among the precursor lesions adjacent to the 23 ARID1A-deficient carcinomas, 86% of the non-atypical endometriosis (12 of 14) and 100% of the atypical endometriosis (14 of 14), benign (3 of 3), and borderline (6 of 6) clear-cell adenofibroma components were found to be ARID1A deficient. In contrast, in the 19 patients with ARID1A-intact carcinomas, all of the adjacent precursor lesions retained ARID1A expression regardless of their types and cytological atypia. Analysis of 22 solitary endometrioses and 10 endometrioses distant from ARID1A-deficient carcinomas showed that all of these lesions were diffusely immunoreactive for ARID1A. Among the 42 clear-cell carcinomas, somatic mutations of PIK3CA were detected in 17 (40%) tumors and majority (71%) of these were ARID1A-deficient carcinomas. These results suggest that loss of ARID1A protein expression occurs as a very early event in ovarian clear-cell carcinoma development, similar to the pattern of PIK3CA mutation recently reported by our group, and frequently coexists (not mutually exclusive) with PIK3CA mutations.

Outcomes of fertility-sparing surgery for stage I epithelial ovarian cancer: a proposal for patient selection.

PURPOSE The objective of this study was to assess clinical outcomes and fertility in patients treated conservatively for unilateral stage I invasive epithelial ovarian cancer (EOC). PATIENTS AND METHODS A multi-institutional retrospective investigation was undertaken to identify patients with unilateral stage I EOC treated with fertility-sparing surgery. Favorable histology was defined as grade 1 or grade 2 adenocarcinoma, excluding clear cell histology. RESULTS A total of 211 patients (stage IA, n = 126; stage IC, n = 85) were identified from 30 institutions. Median duration of follow-up was 78 months. Five-year overall survival and recurrence-free survival were 100% [corrected] and 97.8% for stage IA and favorable histology (n = 108), 100% and 100% for stage IA and clear cell histology (n = 15), 100% and 33.3% for stage IA and grade 3 (n = 3), 96.9% and 92.1% for stage IC and favorable histology (n = 67), 93.3% and 66.0% for stage IC and clear cell histology (n = 15), and 66.7% and 66.7% for stage IC and grade 3 (n = 3). Forty-five (53.6%) of 84 patients who were nulliparous at fertility-sparing surgery and married at the time of investigation gave birth to 56 healthy children. CONCLUSION Our data confirm that fertility-sparing surgery is a safe treatment for stage IA patients with favorable histology and suggest that stage IA patients with clear cell histology and stage IC patients with favorable histology can be candidates for fertility-sparing surgery followed by adjuvant chemotherapy.

PIK3CA mutation is an early event in the development of endometriosis‐associated ovarian clear cell adenocarcinoma

Clear cell adenocarcinoma (CCA), a highly lethal histological subtype of ovarian carcinoma, is a type of human cancer with a high frequency of activating mutations in the PIK3CA gene. In this study, we aimed to determine how these mutations contribute to tumour development of CCAs. Exons 9 and 20 of the PIK3CA gene were analysed by direct genomic DNA sequencing of 23 CCAs with synchronous putative precursor lesions (ie endometriosis adjacent to carcinoma, with or without cytological atypia) and their mutational statuses were compared. Somatic mutations of the PIK3CA gene were detected in 10/23 (43%) carcinomas and in all cases the type of mutation was H1047R in the kinase domain. The identical H1047R mutation was also detected in the coexisting endometriotic epithelium, adjacent to the CCAs, in nine of ten (90%) cases. Moreover, in six of the nine lesions, the H1047R mutation was identified even in the endometrioses lacking cytological atypia. These findings provide evidence that mutations of the PIK3CA gene occur in the putative precursor lesions of CCA, strongly suggesting that they are very early events in tumourigenesis, probably initiating the malignant transformation of endometriosis. A specific kinase inhibitor to mutated PIK3CA may potentially be an effective therapeutic reagent against these carcinomas. Copyright

High-Risk Ovarian Cancer Based on 126-Gene Expression Signature Is Uniquely Characterized by Downregulation of Antigen Presentation Pathway

Purpose: High-grade serous ovarian cancers are heterogeneous not only in terms of clinical outcome but also at the molecular level. Our aim was to establish a novel risk classification system based on a gene expression signature for predicting overall survival, leading to suggesting novel therapeutic strategies for high-risk patients. Experimental Design: In this large-scale cross-platform study of six microarray data sets consisting of 1,054 ovarian cancer patients, we developed a gene expression signature for predicting overall survival by applying elastic net and 10-fold cross-validation to a Japanese data set A (n = 260) and evaluated the signature in five other data sets. Subsequently, we investigated differences in the biological characteristics between high- and low-risk ovarian cancer groups. Results: An elastic net analysis identified a 126-gene expression signature for predicting overall survival in patients with ovarian cancer using the Japanese data set A (multivariate analysis, P = 4 × 10−20). We validated its predictive ability with five other data sets using multivariate analysis (Tothills data set, P = 1 × 10−5; Bonomes data set, P = 0.0033; Dressmans data set, P = 0.0016; TCGA data set, P = 0.0027; Japanese data set B, P = 0.021). Through gene ontology and pathway analyses, we identified a significant reduction in expression of immune-response–related genes, especially on the antigen presentation pathway, in high-risk ovarian cancer patients. Conclusions: This risk classification based on the 126-gene expression signature is an accurate predictor of clinical outcome in patients with advanced stage high-grade serous ovarian cancer and has the potential to develop new therapeutic strategies for high-grade serous ovarian cancer patients. Clin Cancer Res; 18(5); 1374–85. ©2012 AACR.

Paclitaxel Plus Carboplatin Versus Paclitaxel Plus Cisplatin in Metastatic or Recurrent Cervical Cancer: The Open-Label Randomized Phase III Trial JCOG0505

PURPOSE In metastatic or recurrent cervical cancer, cisplatin-based chemotherapy is standard. The JCOG0505 randomized phase III trial evaluated the clinical benefits of carboplatin-based regimen. PATIENTS AND METHODS Eligible patients had metastatic or recurrent cervical cancer and had ≤ one platinum-containing treatment and no prior taxane. Patients were randomly assigned either to conventional paclitaxel plus cisplatin (TP; paclitaxel 135 mg/m(2) over 24 hours on day 1 and cisplatin 50 mg/m(2) on day 2, repeated every 3 weeks) or paclitaxel plus carboplatin (TC; paclitaxel 175 mg/m(2) over 3 hours and carboplatin area under curve 5 mg/mL/min on day 1, repeated every 3 weeks). Primary end point was overall survival (OS). Planned sample size was 250 patients to confirm the noninferiority of TC versus TP with the threshold hazard ratio (HR) of 1.29. RESULTS Between February 2006 and November 2009, 253 patients were enrolled. The HR of OS was 0.994 (90% CI, 0.79 to 1.25; noninferiority P = .032 by stratified Cox regression). Median OS was 18.3 months with TP versus 17.5 months with TC. Among patients who had not received prior cisplatin, OS was shorter with TC (13.0 v 23.2 months; HR, 1.571; 95% CI, 1.06 to 2.32). One treatment-related death occurred with TC. Proportion of nonhospitalization periods was significantly longer with TC (P < .001). CONCLUSION TC was noninferior to TP and should be a standard treatment option for metastatic or recurrent cervical cancer. However, cisplatin is still the key drug for patients who have not received platinum agents.

Actinin-4 gene amplification in ovarian cancer: a candidate oncogene associated with poor patient prognosis and tumor chemoresistance

Actinin-4, an isoform of non-muscular α-actinin, enhances cell motility by bundling the actin cytoskeleton. We previously reported a prognostic implication of high immunohistochemical expression of actinin-4 protein in ovarian cancers. Chromosomal gain or amplification of the 19q12–q13 region has been reported in ovarian cancer. We hypothesized that the actinin-4 (ACTN4) gene might be a target of the 19q12–q13 amplicon and play an essential role of ovarian cancer progression. In total, 136 advanced-stage ovarian cancers were investigated for the copy number of the ACTN4 gene on chromosome 19q13, using fluorescence in situ hybridization, and the correlation of the ACTN4 copy number with actinin-4 protein immunoreactivity and major clinicopathological factors was investigated. A higher copy number (≧4 copies) of the ACTN4 gene was detected in 29 (21%) cases and was highly associated with the intensity of actinin-4 immunoreactivity (P<0.0001), a high histological tumor grade (P=0.030), a clear-cell adenocarcinoma histology (P=0.012), resistance to first-line chemotherapies (P=0.028), and poor patient outcome (P=0.0011). Univariate analyses using the Cox regression model showed that a higher ACTN4 gene copy number was able to predict patient outcome more accurately than high actinin-4 immunoreactivity (relative risk: 2.48 vs 1.55). Multivariate analysis showed that a higher copy number of the ACTN4 gene and the degree of residual disease were independent prognostic factors for overall patient survival. The actinin-4 gene may be a target of the 19q amplicon, acting as a candidate oncogene, and serve as a predictor of poor outcome and tumor chemoresistance in patients with advanced-stage ovarian cancers.

Gene amplification and protein overexpression of MET are common events in ovarian clear-cell adenocarcinoma: their roles in tumor progression and prognostication of the patient

The aim of this study was to assess protein overexpression and gene copy number alterations of MET in ovarian clear-cell adenocarcinoma, and to assess its potential as a novel therapeutic target. Ninety cases of clear-cell adenocarcinoma were analyzed for MET protein overexpression and copy number alterations of the MET gene by immunohistochemistry and brightfield double in situ hybridization, respectively. In addition, 101 cases of the non-clear-cell type ovarian carcinomas at advanced stages were also evaluated for comparison. MET overexpression was assigned when complete membrane staining with moderate or strong intensity was observed in at least 10% of the tumor cells examined. Double in situ hybridization was determined as positive when the tumor exhibited high-level polysomy (≥4 copies in ≥40% of tumor cells) or MET gene amplification. MET overexpression was detected in 20 of 90 clear-cell adenocarcinomas (22%) and none of 111 non-clear-cell type ovarian carcinomas. Double in situ hybridization was positive in 21 of 89 informative clear-cell adenocarcinomas (24%) and only 3 non-clear-cell type ovarian carcinomas (3%). In the whole population, true amplification of the MET gene was detected only in the clear-cell adenocarcinoma histology (five cases, 6%). In clear-cell adenocarcinomas, double in situ hybridization positivity was highly correlated with the presence of MET overexpression and a poorly differentiated histology of tumors (P=0.0105 and 0.00038, respectively). For the patients with clear-cell adenocarcinomas, MET overexpression, as well as advanced clinical stage and the poorly differentiated histology of tumors, was identified as an independent unfavorable prognostic factor for overall survival. In conclusion, among ovarian carcinomas, the amplification of the MET proto-oncogene is highly selective and commonly occurs in clear-cell adenocarcinoma. MET could serve as a biomarker for the prognostication of patients with clear-cell adenocarcinoma and tumor progression, and has potential as a novel therapeutic target for this carcinoma.

PIK3CA mutations and loss of ARID1A protein expression are early events in the development of cystic ovarian clear cell adenocarcinoma

Somatic mutations of PIK3CA and ARID1A are the most common genetic alterations observed in ovarian clear cell adenocarcinomas (CCA). In a previous report, we showed that PIK3CA gene mutations and loss of ARID1A expression occur early during the development of CCA. In the present study, using direct genomic DNA sequencing for exons 9 and 20 of PIK3CA and immunohistochemistry for ARID1A protein expression, we analyzed the association of these molecular alterations with various clinicopathological parameters in a total of 90 cases of primary ovarian CCA, including 42 previously examined cases. The presence of PIK3CA mutations, identified in 34 (39%) of the 88 informative cases, was significantly associated with a grossly cystic tumor, the presence of adjacent endometriosis, prominent papillary architecture of tumor growth, the presence of hyalinized and mucoid stroma, and the absence of clear cell adenofibroma components (P < 0.05, each). There was no significant association of PIK3CA mutations with other clinical variables, such as age, clinical stage, or clinical outcome of the patients. The intensity of immunoreactivity for ARID1A was assigned as negative, weakly positive, and strongly positive in 44%, 22%, and 33% of tumors, respectively. Compared to tumors immunoreactive for ARID1A, ARID1A-negative tumors were significantly associated with the presence of adjacent endometriosis (P = 0.025), but there was no statistically supported association with other examined clinicopathological parameters. Compared with CCAs strongly positive for ARID1A, CCAs negative for ARID1A more frequently harbor PIK3CA mutations (P = 0.013). PIK3CA gene mutations and ARID1A immunohistochemistry lacked prognostic significance. These data further support the idea that these molecular alterations occur as very early events during tumor development of ovarian CCA.

Preoperative determination of several serum tumor markers in patients with primary epithelial ovarian carcinoma.

This study was designed to evaluate the clinical significance of the use of preoperative serum tumor markers in primary epithelial ovarian cancer. Subjects comprised 111 patients with primary epithelial ovarian cancer. Lactate dehydrogenase (LDH), α-hydroxybutyrate dehydrogenase (HBDH), carcinoembryonic antigen (CEA), CA19-9, tissue polypeptide antigen (TPA), CA125 and sialyl TN (STN) serum levels were measured within 7 days before surgery. The tumor marker values were compared with the histopathologic diagnosis. The overall agreement between the test results and the actual outcome was calculated using Student’s t test and analysis of variance (ANOVA). Survival curves were constructed according to the Kaplan-Meier method, and differences in survival were assessed with the log-rank test. The prognostic significance of tumor markers for survival was assessed in a multivariate analysis with the Cox proportional hazards model. Of the tumor markers examined in this study, CA125 showed the highest positive rate (77.6%), followed by 63.2% for STN and 55.9% for CA19-9. When the positive rate was compared according to histologic types, serous cystadenocarcinoma, mucinous cystadenocarcinoma, endometrioid adenocarcinoma and clear cell carcinoma showed the highest positive rates for CA125 (94.1%), CA19-9 (76.9%), CA125 (91.7%) and STN (75.0%), respectively. Regarding the distribution of tumor marker levels according to the FIGO stage, LDH, HBDH, TPA and CA125 were correlated with the clinical stage while CEA, CA19-9 and STN did not show any correlation. From analyses of tumor marker levels according to histologic types, all patients with a ratio of CA125 to CEA of >1,000 had serous cystadenocarcinoma and a ratio of CA125 to CA19-9 of >50 showed serous cystadenocarcinoma or endometrioid adenocarcinoma. On the other hand, all patients with a ratio of LDH or HBDH to CA19-9 of <1.0 had mucinous cystadenocarcinoma or clear cell carcinoma. From univariate analysis, the survival time of patients with elevated CA125, TPA or STN was significantly shorter than that of patients with normal CA125, TPA or STN levels. When the Cox’s proportional hazard model was used, we identified age, clinical stage, clear cell carcinoma and serum STN as independent prognostic factors. Serum CA125, TPA or STN may give significant prognostic information in epithelial ovarian carcinoma. It is noteworthy that STN has been identified as an independent prognostic factor and has a high rate of positivity in clear cell carcinoma.