Clear-cell cancer of the ovary-is it chemosensitive?

A multi-ethnic analysis of immune-related gene expression signatures in patients with ovarian clear cell carcinoma

Little is known about the immune environment of ovarian clear cell carcinoma (OCCC) and its impact on various ethnic backgrounds. The aim of this OCCC immune‐related gene expression signatures (irGES) study was to address the interaction between tumour and immune environment of ethnically‐diverse Asian and Caucasian populations and to identify relevant molecular subsets of biological and clinical importance. Our study included 264 women from three different countries (Singapore, Japan, and the UK) and identified four novel immune subtypes (PD1‐high, CTLA4‐high, antigen‐presentation, and pro‐angiogenic subtype) with differentially expressed pathways, and gene ontologies using the NanoString nCounter PanCancer Immune Profiling Panel. The PD1‐high and CTLA4‐high subtypes demonstrated significantly higher PD1, PDL1, and CTLA4 expression, and were associated with poorer clinical outcomes. Mismatch repair (MMR) protein expression, assessed by immunohistochemistry, revealed that about 5% of OCCCs had deficient MMR expression. The prevalence was similar across the three countries and appeared to cluster in the CTLA4‐high subtype. Our results suggest that OCCC from women of Asian and Caucasian descent shares significant clinical and molecular similarities. To our knowledge, our study is the first study to include both Asian and Caucasian women with OCCC and helps to shine light on the impact of ethnic differences on the immune microenvironment of OCCC. © 2021 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

Omission of adjuvant therapy in stage I clear cell ovarian cancer: Review of the BC Cancer experience

Background

Since 2012, the BC Cancer provincial treatment guideline for surgically staged stage IA/B and IC1 (defined by intraoperative rupture only) clear cell ovarian cancer (CCOC) has been to offer observation only. We reviewed the clinical outcomes of all stage I CCOC patients since policy implementation.

Methods

A retrospective, population-based cohort study of all stage I CCOC patients operated on between April 2012 and December 2017 was conducted. Patient, tumor, surgical and clinical outcome data were collected. Survival analysis was conducted using Kaplan-Meier methods.

Results

78 patients with stage I disease were identified. 40 patients with stages IA/B and IC1, who underwent post-operative observation, were included in the analysis. Lymph node dissection was omitted in 20 patients (50%). Median duration of follow-up was 36 months. There were 4 recurrences (10%), 3 metastatic. The 5-year disease-free survival is 90%, and the 5-year overall survival is 95% for stage IA/B and 90% for stage IC1 (p = 0.645). In comparison, 5-year overall survival for stage IC2 (surface involvement) and IC1 with sharp dissection (all received adjuvant chemotherapy) is 82% (p < 0.001) and for stage IC3 (positive washings) was 23% (p < 0.001).

Conclusion

Adjuvant therapy can be safely omitted in patients with stage I A/B and IC1 CCOC. Recurrence rates are low and survival is >90% at 5 years. Stage IC2 /IC3 had worse outcomes, thus stage I substage is instrumental in predicting clinical outcomes for CCOC. Lymph node metastases are rare in stage IA/B/C1 CCOC as absence of lymphadenectomy did not increase the risk of disease recurrence.

Prognostic Value of Serum CA19-9 and Perioperative CA-125 Levels in Ovarian Clear Cell Carcinoma

BACKGROUND

There are no effective biomarkers for surveillance in ovarian clear cell carcinoma (OCCC), and the value of carbohydrate antigen 125 (CA-125) is limited. We sought to determine the value of both carbohydrate antigen 19-9 (CA19-9) and CA-125 levels postoperatively on the prognosis for OCCC.

METHODS

A total of 130 patients with OCCC who were consecutively treated by cytoreduction at Fudan University Shanghai Cancer Center were reviewed retrospectively. Univariate log-rank analyses and Cox regression multivariate analyses were performed to identify predictors of recurrence-free (RFS) and overall survival (OS) rates.

RESULTS

The survival in patients with postoperative normalization of CA-125 was significantly better than those with decreased but still elevated CA-125 (5-year RFS rates, 57.9% vs 45.2%, P = 0.046; 5-year OS rates, 81.4% vs 54.4%, P = 0.016), or those with increased CA-125 (5-year RFS rates, 57.9% vs 29.2%, P = 0.001; 5-year OS rates, 81.4% vs 33.6%, P < 0.001). An elevated level of postoperative CA-125 level was an independent risk factor for recurrence and survival [RFS: hazard ratio (HR), 2.2; P = 0.033; OS: HR, 4.3; P = 0.019]. Elevated postoperative CA19-9 was an independent risk factor for both RFS and OS in patients with normal postoperative CA-125 levels (RFS: HR, 5.0; P = 0.005; OS: HR, 1.1; P = 0.035).

CONCLUSIONS

Combining postoperative CA19-9 and CA-125 appeared to be of great clinical value for prognosis in patients with OCCC after initial debulking.

The prognostic value of pretreatment CA-125 levels and CA-125 normalization in ovarian clear cell carcinoma: a two-academic-institute study

OBJECTIVES

The present study investigated the clinical implications of pretreatment carbohydrate antigen 125 (CA-125) levels and CA-125 normalization in patients with ovarian clear cell carcinoma (CCC), and it provides useful information for the improvement of monitoring strategies for this lethal disease.

METHODS

The medical records of patients with ovarian CCC who had undergone primary staging surgery or cytoreductive surgery followed by systemic chemotherapy were retrospectively reviewed. A range of clinico-pathological parameters were collected and examined.

RESULTS

A total of 375 women were included in the analysis. FIGO stage (p < 0.001) was identified as the only significant prognostic factor for relapse. Residual tumor and advanced stage (p = 0.001 and p < 0.001, respectively) were identified as independent adverse factors for survival. The potential risk factors associated with elevated pretreatment CA-125 levels included advanced-stage disease, positive residual tumors and negative endometriosis (p < 0.001, p = 0.001 and p <0.001, respectively). Pretreatment CA-125 levels were not associated with relapse-free survival (RFS) or overall survival (OS) (p = 0.060 and p = 0.176, respectively). CA-125 normalization after chemotherapy exhibited a positive linear correlation with advanced stage (r = 0.97, p = 0.001) and residual tumor (r = 0.81, p = 0.027) and a negative relationship with 5-year RFS (r = -0.97, p = 0.002) and 5-year OS (r = -0.97, p= 0.001). Patients with CA-125 levels that normalized before cycle 2 of chemotherapy had a similar prognosis as patients whose CA-125 levels normalized prior to chemotherapy (RFS: p = 0.327; OS: p = 0.654). By contrast, patients with CA-125 levels that normalized after cycle 2 of chemotherapy or never normalized were significantly more likely to experience disease progression.

CONCLUSIONS

Pretreatment CA-125 levels are not very useful for predicting clinical outcome. CA-125 levels following treatment are a valid indicator for treatment monitoring. CA-125 normalization after the completion of cycle 1 of chemotherapy represents a distinct inflection point for decreased RFS and OS.

CCNE1 copy-number gain and overexpression identify ovarian clear cell carcinoma with a poor prognosis

Ovarian clear cell carcinoma is a unique type of ovarian cancer, often derived from endometriosis, and advanced-stage disease has a dismal prognosis primarily due to the resistance to conventional chemotherapy. Previous studies have shown frequent somatic mutations in ARID1A, PIK3CA, hTERT promoter, and amplification of ZNF217; however, the molecular alterations that are associated with its aggressiveness remain largely unknown. This study examined and compared cyclin E1 expression in endometriosis-related ovarian tumors, with the aim of determining the relationship between hTERT mutations and ARID1A expression and evaluating the effects of these molecular alterations on patient survival. We performed immunohistochemistry on 207 tumors [clear cell carcinoma (n=120), endometrioid carcinoma (n=49), and seromucinous tumors (n=38)], followed by two-color fluorescence in situ hybridization (n=88) and compared with ARID1A expression and hTERT promoter mutations in the same samples. Cyclin E1 overexpression and CCNE1 copy-number gain occurred in 23.3% and 14.8% of ovarian clear cell carcinomas, respectively, but they were not detected in any of the other endometriosis-related tumors. All cases with CCNE1 copy-number gain demonstrated an intense cyclin E1 immunoreactivity (P<0.001). Cyclin E1 overexpression was positively correlated with hTERT promoter mutations (P=0.01), but not with the loss of ARID1A expression. A multivariate analysis revealed that CCNE1 overexpression predicts poor overall survival, even after adjusting for stage and age. Specifically, CCNE1 overexpression and copy-number gain were both correlated with a poor outcome in patients with stage I disease. Moreover, the subset with CCNE1 overexpression and ARID1A retention demonstrated the worst outcome. Our findings suggest that gene copy-number gain and upregulation of CCNE1 occur in ovarian clear cell carcinoma and are associated with a worse clinical outcome, dictating the survival of early-stage patients, and that these molecular alterations are unique to clear cell carcinoma among different types of endometriosis-related ovarian neoplasms.

Magnetic resonance imaging for distinguishing ovarian clear cell carcinoma from high-grade serous carcinoma

BACKGROUND

To compare the magnetic resonance imaging (MRI) features of ovarian clear cell carcinoma (CCC) and high-grade serous carcinoma (HGSC), to distinguish CCC from HGSC.

METHODS

MRI features (laterality, shape, size, configuration, papillary projection, signal intensity, enhancement, peritoneal implant, lymphadenopathy, ascites) of 40 tumors in 37 patients with CCC, confirmed by surgery and pathology, were compared with those of 62 tumors in 40 patients with HGSC. Statistical analysis was performed using Mann-Whitney and Fisher's exact tests.

RESULTS

There was a statistically significant difference in the mean maximum diameter, laterality, and FIGO stage (P = 0.002, P < 0.001, P < 0.001, respectively) between CCC and HGSC. Compared to HGSCs, CCCs were more frequently oval (30/40, 75 % vs 12/62, 19 %; P < 0.001), more often cystic (21/40, 53 % vs 8/62, 13 %; P < 0.001) and unilocular (23/29, 79 % vs 7/31, 23 %; P < 0.001), had T1-hyperintense cystic components more often (18/29, 62 % vs 5/29, 17 %; P < 0.001), had larger papillary projections (5.13 ± 0.4 cm vs 2.91 ± 0.3 cm; P < 0.001), were peritoneally implanted less frequently (P = 0.001) and had fewer ascites (P < 0.001).

CONCLUSIONS

CCC typically showed an oval, unilocular cystic mass with large papillary projection and T1-hyperintense cystic components. MRI could be helpful for distinguishing CCC from HGSC.

Clear cell carcinomas of the ovary: a mono-institutional study of 73 cases in China with an analysis of the prognostic significance of clinicopathological parameters and IMP3 expression

Background

Ovarian clear cell carcinoma (CCC) is an uncommon subtype of ovarian epithelial tumor. The prognostic significance of its clinicopathological parameters is discordant, with the exception of stage as the adverse prognostic factor. The present study aimed to evaluate the prognostic significance of its clinicopathological characteristics and the expression of IMP3 (Insulin-like growth factor-II mRNA-binding protein 3, IMP3 or IGF2BP3) in Chinese patients with primary pure CCC.

Methods

We collected clinicopathological data from 73 cases with a minimum of 5 years of follow-up and evaluated the expression of IMP3 by immunohistochemistry.

Results

In total, 49.3 % of the patients were in stage I. Advanced stages were closely related to poor prognosis of disease-free survival (DFS) and overall survival (OS) (P < 0.005). Patients with CCC coexisting with endometriosis tended to be younger and to have unilateral involvement but did not exhibit differences in prognosis compared with patients with CCC without endometriosis. Other histological features such as growth pattern, mitosis, and necrosis did not have prognostic significance. IMP3 was positive in 63 % of patients (46 of 73 cases); Thus, positive expression of IMP3 is an adverse prognostic marker in terms of OS (P = 0.012), even in stage I patients (P = 0.038).

Conclusions

The present study demonstrates that IMP3 expression is a prognostic marker, with the exception of stage. IMP3 represents a biomarker of unfavorable prognosis even in stage I patients.

HNF1β drives glutathione (GSH) synthesis underlying intrinsic carboplatin resistance of ovarian clear cell carcinoma (OCCC)

Chemoresistance to platinum-based antineoplastic agents is a consistent feature among ovarian carcinomas; however, whereas high-grade serous carcinoma (OSC) acquires resistance during chemotherapy, ovarian clear cell carcinoma (OCCC) is intrinsically resistant. The main objective of this study was to explore, in vitro and in vivo, if hepatocyte nuclear factor 1β (HNF1β) and glutaminolysis contribute for the resistance of OCCC to carboplatin through the intrinsically increased GSH bioavailability. To disclose the role of HNF1β, experiments were also performed in an OSC cell line, which does not express HNF1β. Metabolic profiles, GSH quantification, HNF1β, and γ-glutamylcysteine ligase catalytic subunit (GCLC) and modifier subunit (GCLM) expression, cell cycle, and death were assessed in ES2 cell line (OCCC) and OVCAR3 cell line (OSC); HNF1β knockdown was performed in ES2 and murine model of subcutaneous and peritoneal OCCC tumors was established to test buthionine sulphoxamine (BSO), as a sensitizer to carboplatin. Glutaminolysis is activated in ES2 and OVCAR3, though ES2 exclusively synthesizes amino acids and GSH. ES2 cells are more resistant to carboplatin than OVCAR3 and the abrogation of GSH production by BSO sensitizes ES2 to carboplatin. HNF1β regulates the expression of GCLC, but not GCLM, and consequently GSH production in ES2. In vivo, BSO prior to carboplatin reduces dramatically subcutaneous tumor size and GSH levels, as well as peritoneal dissemination. Our study discloses HNF1β as the mediator of intrinsic OCCC chemoresistance and sheds a light to re-explore a cancer adjuvant therapeutic approach using BSO to overcome the lack of efficient therapy in OCCC.

Salvage Chemotherapy for Patients With Recurrent or Persistent Ovarian Clear Cell Carcinoma: A Retrospective Study of 164 Cases

The purpose of this study was to evaluate the effects of salvage chemotherapy on recurrent or persistent ovarian clear cell carcinoma (CCC) with the goal of identifying a more rational treatment regimen for this lethal disease.The medical records of patients with CCC were retrospectively reviewed to select patients that were subsequently treated for recurrent or persistent disease.Of the 164 women with recurrent or persistent CCC, 485 chemotherapy courses with 1766 cycles were administered. Overall, the clinical benefit rate (CBR) was 39.4%, and the mean progression-free survival (PFS) was 4.5 months. Grade 3/4 toxicities occurred in 94 courses (19.4%). The CBR for TC was 45.1%, with a PFS of 3.7 months. Compared to that of TC, the CBRs for PC and CC were significantly lower (P = 0.020 and 0.021, respectively). The CBRs and PFS for PAF-C were slightly higher (P = 0.518 and 0.077, respectively), but showed a significantly higher adverse event rate (AER, P = 0.039). The CBR for bevacizumab was 50% with an extraordinarily long PFS (49.8 months). Gemcitabine and oxaliplatin had similar values for CBRs (44.4% and 44.1%) and PFS (2.5 and 3.4 months), respectively. Docetaxel (weekly) exhibited a notably low AER of 2.7%, and topotecan was associated with a relatively long PFS (7.7 months).For cis/carboplatin-pretreated patients, the existing active agents, such as oxaliplatin, gemcitabine, topotecan, and especially bevacizumab, are promising. Docetaxel (weekly) is well tolerated and might offer a particularly viable option for heavily pretreated patients. However, additional research to identify for a continued search for the optimal combination of chemotherapeutics or novel agents is still warranted.

Alterations in the mitochondrial responses to PENAO as a mechanism of resistance in ovarian cancer cells

OBJECTIVE

The purpose of this study was to test PENAO, a promising new organoarsenical that is in phase 1 testing in patients with solid tumours, on a range of ovarian cancer cell lines with different histotypes, and to understand the molecular basis of drug resistance exhibited by the endometrioid ovarian cancer cell line, SKOV-3.

METHODS

Proliferation arrest and cell death induced by PENAO in serous (OVCAR-3), endometrioid (SKOV-3, TOV112D), clear cell (TOV21G) and mucinous (EFO27) ovarian cancer cells in culture, and anti-tumour efficacy in a murine model of SKOV-3 and OVCAR-3 tumours, were measured. Cells were analysed for cell cycle arrest, cell death mechanisms, reactive oxygen species production, mitochondrial depolarisation, oxygen consumption and acid production.

RESULTS

PENAO demonstrated promising anti-proliferative activity on the most common (serous, endometrioid) as well as on rare (clear cell, mucinous) subtypes of ovarian cancer cell lines. No cross-resistance with platinum-based drugs was evident. Endometrioid SKOV-3 cells were, however, shown to be resistant to PENAO in vitro and in a xenograft mouse model. This resistance was due to an ability to cope with PENAO-induced oxidative stress, notably through heme oxygenase-1 induction, and a shift in metabolism towards glycolysis. The adaptive glycolytic shift in SKOV-3 was targeted using a mTORC1 inhibitor in combination with PENAO. This strategy was successful with the two drugs acting synergistically to inhibit cell proliferation and to induce cell death via apoptosis and autophagy.

CONCLUSION

Mitochondria/mTOR dual-targeting therapy may constitute a new approach for the treatment of recurrent/resistant forms of epithelial ovarian cancer.

Ovarian cancer: new developments in clear cell carcinoma and hopes for targeted therapy

Until recently, ovarian clear cell carcinoma was recognized by its unique morphology and unfavorable patient outcome primarily due to tumor chemoresistance. Recently, specific molecular characteristics of ovarian clear cell carcinoma, such as PI3CA mutation, ARID1a mutation and MET amplification, have been elucidated. In addition, an association between endometriosis and the tumor has also been a focus of research in recent years. The aim of this review is to discuss the specificity and importance of molecular changes and various intriguing points that are not solved until today. Finally, future aspects, including hopes for the development of novel therapies, are discussed.

Second-line chemotherapy in recurrent clear cell ovarian cancer: results from the multicenter italian trials in ovarian cancer (MITO-9)

BACKGROUND AND AIMS

Ovarian clear cell carcinoma (CCC) has a poorer prognosis than other subtypes of ovarian cancer. In this study, we evaluated the responsiveness to second-line chemotherapy in recurrent ovarian CCC.

METHODS

The MITO-9 project investigated a cohort of patients observed between 1991 and 2007 in 20 centers. We identified 72 out of 240 patients with recurrent disease (28% stage I-II and 72% stage III-IV at diagnosis).

RESULTS

In 56% of patients, the clear cell histology was pure. Twenty-five patients were platinum-resistant, 18 were platinum-sensitive with a platinum-free interval (PFI) of 6-12 months, and 29 had a PFI >12 months. Upon recurrence, 47% of patients were treated with platinum chemotherapy according to the PFI. The overall response rate (RR) to platinum was 80%, with 55, 100, and 80% RR in patients with PFI of 6-12, >12, and >24 months. The RR to nonplatinum agents in resistant patients was 33%. Among the nonplatinum agents used in primary and secondary resistant cases, gemcitabine, administered in 12 cases, had a higher activity (RR = 66%) compared to topotecan or liposomal doxorubicin (n = 31; RR = 33 and 10%, respectively).

CONCLUSIONS

This study showed that the treatment of recurrent ovarian CCC should be based on the PFI as in the other subtypes. Data in platinum-resistant patients suggest gemcitabine as the drug with the highest activity. We recommend that gemcitabine be studied prospectively in a phase 2 trial.

New perspectives on molecular targeted therapy in ovarian clear cell carcinoma

Ovarian clear cell carcinomas (OCCCs) account for about 5–13% of all epithelial ovarian carcinomas in Western populations. It is characterised by resistance to conventional platinum-based chemotherapy, and new therapeutic strategies are urgently required. This article will focus on how recent discoveries have enhanced our understanding of the molecular pathogenesis of OCCCs, leading to new therapeutic opportunities. These include mutations in ARID1A, which provides a link to endometriosis, upregulation of the phosphatidylinositol 3-kinase/AKT pathway, particularly through mutations of PIK3CA and inactivation of PTEN, and increased activity of pathways involved in angiogenesis. Targeting HER2, apoptotic escape mechanisms and mismatch repair defects offer additional opportunities for treating this enigmatic tumour subtype.

Expression of angiogenic chemokines in ovarian clear cell carcinoma

AIMS

The aim of this study was to assess the expression of angiogenic chemokines (CXCR4/CXCL12) and the vascular endothelial growth factor in ovarian clear cell carcinoma, comparing levels against those in ovarian high-grade serous carcinoma.

MATERIAL AND METHODS

Tissue microarray samples from 136 cases of epithelial ovarian carcinoma (108 high-grade serous carcinoma and 28 clear cell carcinoma) were reviewed with World Health Organization histological criteria strictly applied to categorize cases according to histological subtype. Only cases without prior exposure to chemotherapy were included. Sections were stained with vascular endothelial growth factor, CXCR4, CXCL12 and assessed using conventional histological scoring (H-scoring).

RESULTS

  Patients with clear cell carcinoma presented at an early stage of the disease (74% stage 1 and 2) and had a significantly better progression-free (P=0.042) survival than those with high-grade serous carcinoma. Low expression profile of the tested markers was seen in cases of clear cell carcinoma contrary to that seen in high-grade serous carcinoma.

CONCLUSION

The current study reports, for the first time, the difference in expression of a set of angiogeneic prognostic markers between clear cell carcinoma and high-grade serous carcinoma, offering a possible explanation for the apparent chemotherapy resistance. These results are relevant for the design of future clinical studies of first-line treatment for patients with ovarian clear cell carcinoma.

Clear cell carcinoma of the ovary: a review of the literature

OBJECTIVE

Different histologic types of epithelial ovarian cancer may represent different diseases with unique clinical and molecular characteristics. Clear cell carcinoma (CCC) of the ovary has been reported as having a worse prognosis than high grade serous epithelial ovarian cancer (EOC). This article critically reviews the literature pertinent to the pathology, pathogenesis, diagnosis, management, and outcome of patients with ovarian CCC.

METHODS

MEDLINE was searched for all research articles published in English between January 01, 1977 and January 30, 2012 which reported on patients diagnosed with ovarian CCC. Given the rarity of this tumor, studies were not limited by design or number of reported patients.

RESULTS

Ovarian CCC tumors represent 5-25% of ovarian cancers. Its histologic diagnosis can be challenging, resulting often times in misclassification of these tumors. Ovarian CCC tends to present at earlier stages and has been associated with endometriosis, ARID1A and PIK3CA mutations. When compared to stage-matched controls, patients with early-stage ovarian CCCs may have a better prognosis than patients with high-grade serous tumors. For those with advanced stage disease, high-grade serous histology confers a better prognosis than ovarian CCC. Patients with Stage IC-IV have a relatively poor prognosis and efforts should center in discovery of more effective treatment strategies.

CONCLUSIONS

Ovarian CCC is a biologically distinct entity, different from high-grade serous EOC. Future studies should explore the role of targeted therapies in the management of ovarian CCC.

Low-stage ovarian clear cell carcinoma: population-based outcomes in British Columbia, Canada, with evidence for a survival benefit as a result of irradiation

PURPOSE

To evaluate the population-based outcomes of stage I and II ovarian clear cell carcinoma (OCCC) in a North American population treated with carboplatin/paclitaxel and abdominopelvic irradiation.

PATIENTS AND METHODS

Retrospective analysis was performed of 241 patients referred in the carboplatin/paclitaxel era. Irradiation was to be used with a few defined exceptions. However, because of differing beliefs as to its effectiveness, its use was consistently avoided by specific oncologists, allowing the opportunity to study its possible effect on disease-free survival (DFS) in these concurrent cohorts.

RESULTS

Five- and 10-year DFS rates were 84% and 70% for stage IA/B; 67% and 57% for stage IC; and 49% and 44% for stage II, respectively. Five- and 10-year DFS rates for those with stage IC disease based purely on rupture were similar to rates for patients with stage IA/B, at 92% and 71%, respectively. The remaining patients with stage IC had 48% 5- and 10-year DFS. Multivariate analysis using a decision tree identified positive cytology as the most important factor (72% relapse rate if positive and 27% if negative or unknown). If, in addition, the capsule surface was involved, then the relapse rate was 93%. Irradiation had no discernible survival benefit for patients with stage IA and IC (rupture alone), whereas for the remainder of patients with stage IC and stage II, it improved DFS by 20% at 5 years (relative risk, 0.5); the benefit was most evident in the cytologically negative/unknown group.

CONCLUSION

DFS is similar in this North American population with early OCCC to the DFS reported in Asia. A potential benefit from irradiation was evident in a subset.

Prognosis of ovarian clear cell carcinoma compared to other histological subtypes: a meta-analysis

OBJECTIVE

To compare the survival outcome between clear cell carcinoma (CCC) and other histological subtypes in epithelial ovarian carcinoma (EOC).

METHODS

From January 1974 to February 2011, we identified a total of 31,800 (CCC; 2152, non-CCC; 29648) patients from 12 studies meeting the inclusion criteria.

RESULTS

Heterogeneity tests demonstrated significant between-study variation (I(2)=92.1%) with no significant difference in hazard ratio (HR) for death between CCC and non-CCC (HR; 1.16, 95% CI; 0.85-1.57, random-effects model). Comparing the HR based on stage I+II, and stage III+IV, between CCC and non-CCC, showed that CCC patients had a higher hazard rate for death than those with non-CCC of the ovary (stage I+II; HR; 1.17, 95% CI; 1.01-1.36, stage III+IV; HR; 1.65, 95% CI; 1.52-1.79). In a comparison of CCC and serous EOC, advanced stage (III and IV) CCC only showed a poorer hazard rate for death than serous EOC (HR; 1.71, 95% CI; 1.57-1.86).

CONCLUSION

This analysis suggests that ovarian CCC patients had poorer prognosis than those with other histological subtypes of EOC, especially in advanced EOC stages. Different treatment strategies may be needed for patients with ovarian CCC.

Exploring palliative treatment outcomes in women with advanced or recurrent ovarian clear cell carcinoma

OBJECTIVE

Clear cell carcinoma (CCC) of the ovary is increasingly recognized as responding poorly to chemotherapy (CT). This review examines the outcomes achieved with a variety of CT regimens, looking for evidence of activity that might guide the development of more effective treatments.

METHODS

A retrospective chart review of all cases of CCC referred to the BC Cancer Agency (BCCA) between 2000 and 2008 was conducted. Data were collected from those with primarily advanced disease and from those who recurred after adjuvant treatment. Outcomes were measured using broad definitions of treatment benefit (any objective or subjective evidence of disease control) in order to reflect the real-life use of palliative therapy.

RESULTS

There were 158 women with pure CCC. First-line therapy for advanced disease was delivered to 33 patients. Second- and third-line treatment was delivered to 47 and 25 patients, respectively. The total number of treatment courses was 105: 88 CT-alone courses, 14 radiation therapy (RT)-alone and 3 combined modality. Treatment benefit was recorded in 24% of patients receiving CT, 64% of patients receiving RT, and each who received combined modality treatment. There was no CT drug class identified as obviously efficacious.

CONCLUSION

Most patients with advanced or recurrent CCC have a low benefit-to-failure ratio from palliative CT. The role of RT and targeted agents must be explored to improve clinical outcomes for such patients.

Clear cell carcinoma of the ovary: a report from the first Ovarian Clear Cell Symposium, June 24th, 2010

OBJECTIVES

Recent literature has highlighted histological types of ovarian carcinoma as distinct diseases, each with unique clinical and molecular features. Historically, the diagnosis of ovarian clear cell carcinoma (CCC) has been of concern to both patients and physicians due to reports that CCC is associated with a worse prognosis than the more common serous type of ovarian carcinoma (HGSC). This review discusses the unique features of ovarian CCC.

METHODS

In June of 2010, a group of researchers and clinicians convened in Vancouver to review and discuss the clinical, pathological, molecular, and treatment-related features of CCC.

RESULTS

CCC is the second most common type of ovarian epithelial cancer, representing 5-25% of ovarian carcinomas. It is characterised by its association with endometriosis, and frequent mutations of ARID1A and PIK3CA. Low-stage CCC appears to have a better outcome than stage matched HGSC, while the opposite is true for high-stage disease, suggesting that the current standard treatments applied to HGSC are ineffective for CCC.

CONCLUSIONS

Ovarian CCC is highly distinct from HGSC, and a clearer understanding of the basic biology of this disease is needed. Alternative therapies should be explored: irradiation and targeting disease-specific molecular markers should be examined in greater detail. Finally, novel approaches to clinical trial design are needed due to the smaller numbers of patients affected.

Screening, epidemiology, molecular biology, and treatment strategies for endometriosis-associated ovarian cancer

Objectives

This article reviews recent data on the biology, pathogenesis and pathophysiology of the different entity of epithelial ovarian cancer (EOC).

Study design

The present article reviews the English language literature for screening, epidemiology, clinical diagnosis, natural history, preclinical and clinical trials, and promising molecular targets on EOC, particularly for clear cell EOC (cEOC) based on the gene expression profiling studies.

Results

Prospective ovarian cancer screening trials in Japan showed that (1) serous-type EOC (sEOC) may exhibit a rapid progression possibly through de novo carcinogenesis, (2) the EOC risk was elevated significantly among patients with ovarian endometrioma (SIR = 8.95), (3) advancing age (>40 years) and the diameter of endometriomas (>9 cm) were independent predictors of development of EOC, (4) the benign-appearing ovarian masses are present several years before the EOC diagnosis in patients with endometriosis-associated EOC, and (5) the slightly elevated CA125 level is also typically present many years (>3 years) before the diagnosis in these patients. Upregulation of HNF-1beta and PLK-Emi1 genes were specifically detected in cEOC. In addition, the therapy currently used in renal cell carcinoma (RCC) should be considered as an attractive therapeutic option for cEOC.

Conclusions

Ovarian endometrioma could be viewed as a neoplastic process, particularly in perimenopausal women. Understanding the mechanisms of endometriosis development and elucidating its pathogenesis and pathophysiology are intrinsic to prevention and the search for effective therapies of endometriosis-associated EOC.

Theoretical model of treatment strategies for clear cell carcinoma of the ovary: focus on perspectives

OBJECTIVES

Among epithelial ovarian cancer (EOC), clear cell carcinomas (CCC) differ from the other histologic types with respect to their clinical characteristics, carcinogenesis and prognosis. The aim of this review is to summarize the current knowledge and future perspective on the new therapeutic targets and treatment strategies for CCC.

MATERIALS AND METHODS

The present article reviews the English language literature for preclinical and clinical trials and promising molecular targets on CCC of the ovary, based on the gene expression profiling studies.

RESULTS

Here, we show that (1) the expression of the genes involved in transcription, signaling, cell cycle, adhesion, matrix, proteinase, and detoxification was greatly increased in the CCC carcinogenesis; (2) upregulation of hepatocyte nuclear factor-1beta (HNF-1beta) and Polo-like kinase (PLK)-Early mitotic inhibitor-1 (Emi1) as well as their downstream targets are specifically found in most CCC. The promising molecular targeting approach will emerge in the context of HNF-1beta and PLK-Emi1 biology; and 3) several significant common pathways observed in CCC of the ovary overlap the datasets identified in CCC of the kidney. To improve the outcome in CCC therapy, we must learn various adaptive treatment strategies for renal CCC, although it is not supported by any preliminary clinical data.

CONCLUSION

The inhibitors that target HNF-1beta and PLK-Emi1 and their downstream signaling molecules would be evaluated. In addition, the therapy currently used in renal CCC should be considered as an alternative for the present treatments or an attractive therapeutic option for ovarian CCC. The challenges accompanying the recent advance are described in this review article.

A heavily pretreated patient with recurrent clear cell adenocarcinoma of the ovary in whom carcinomatous peritonitis was controlled successfully by salvage therapy with gemcitabine

INTRODUCTION

Advanced clear cell adenocarcinoma of the ovary is a histologic type with an extremely poor prognosis. No reports have been published concerning useful drugs for salvage chemotherapy for this type of cancer. We performed salvage therapy with gemcitabine in a patient with multiple-drug- resistant, unresectable recurrent clear cell adenocarcinoma of the ovary and succeeded in stabilizing recurrent lesions and controlling carcinomatous peritonitis.

CASE REPORT

A 55-year-old woman was in Stage IIIc of clear cell adenocarcinoma of the ovary. She had recurrent tumors after primary cytoreductive surgery, which were unresectable and also resistant to paclitaxel, carboplatin, irinotecan, and oral etoposide. After three courses of fourth-line chemotherapy with gemcitabine for the treatment of carcinomatous peritonitis and hepatic and splenic metastatic lesions, serum CA-125 and the severity of ascites showed marked decreases, and its efficacy for the hepatic and splenic metastatic lesions was classified as 5-month stable disease. The toxicity of this drug was in the acceptable range.

CONCLUSION

Gemcitabine is also useful for heavily pretreated clear cell adenocarcinoma of the ovary. It is necessary to consider the use of drugs without cross resistance to platinum and taxanes in the selection of drugs for this cancer.

Survival and prognostic factors in early-stage epithelial ovarian carcinoma treated with taxane-based adjuvant chemotherapy

The present study was undertaken with the question about the outcome (recurrence-free survival, [RFS]) after adjuvant chemotherapy with taxane and carboplatin in the early stages of epithelial ovarian cancer after primary surgery. Treatment-related toxicity was also evaluated. A total of 113 patients were included in this study. The 5-year RFS rate for all 113 patients treated with adjuvant chemotherapy including taxane and carboplatin after primary surgery was 79%. The 5-year RFS rate for 85 patients in FIGO stage I was 85% and for 18 patients in FIGO stage II, it was 44%. For clear-cell carcinomas, the RFS was 87%. In univariate analysis, recurrent disease was associated with both FIGO stage and tumor grade, but in multivariate logistic regression analysis of prognostic factors for tumor recurrences, only FIGO stage (stage I versus stage II) was a significant and independent prognostic factor. However, an odds ratio (OR) of 1.9 for tumor grade (grade 3 versus grades 1-2) demonstrated two times increased risk for recurrence in a patient with a grade 3 tumor compared with grade 1-2 tumors. Furthermore, an OR of 0.39 for lymph node sampling versus no sampling meant 61% reduced risk for recurrence for a patient who had undergone lymph node sampling at surgical staging laparotomy. The major toxicities in the present study were myelosuppression (46%) and neurotoxicity (34%). Despite the use of prophylaxis, severe paclitaxel-related hypersensitivity occurred in three patients (3%).

Lack of effective systemic therapy for recurrent clear cell carcinoma of the ovary

OBJECTIVE

Clear cell carcinoma of the ovary is an aggressive tumor characterized by relative chemoresistance and a poor prognosis. The purpose of this study was to review our experience with recurrent clear cell carcinoma of the ovary to evaluate its responsiveness to systemic cytotoxic and hormonal agents.

METHODS

All patients diagnosed with clear cell carcinoma of the ovary seen at our institution between 1990 and 2002 were identified and their medical records reviewed. Eligibility criteria were: 1) primary diagnosis of clear cell carcinoma of the ovary, 2) measurable recurrent disease, 3) treatment of recurrent disease with 1 or more systemic regimens, and 4) adequate clinical information. End points were clinical response, progression-free survival, and overall survival.

RESULTS

Fifty-one patients treated for recurrent clear cell carcinoma were identified. The patients received a total of 105 regimens (344 cycles of therapy). Among patients with platinum-sensitive disease (n=22 regimens), 2 patients (9%) had partial responses to retreatment with carboplatin plus paclitaxel, and 4 (18%) had stable disease. Among patients with platinum-resistant disease (n=83 regimens), only 1 patient (1%) had a partial response - to gemcitabine - and 1 patient had stable disease in response to 2 different regimens-paclitaxel and gemcitabine. The median progression-free survival was 8 months, and the median overall survival was 18 months.

CONCLUSION

Our findings suggest that recurrent clear cell carcinoma of the ovary is particularly chemoresistant. A continued search for more active, targeted agents is warranted.

Treatment issues in clear cell carcinoma of the ovary: a different entity?

BACKGROUND

Ovarian clear cell carcinoma (OCCC) is a distinct histopathologic subtype of epithelial ovarian cancer (EOC) with an incidence of <5% of all ovarian malignancies. Our goal was to review the clinical features and management of patients with OCCC.

METHODS AND RESULTS

We performed a PubMed search using the phrase "clear cell ovarian cancer." We reviewed 54 articles referring to OCCC. OCCC patients have a high incidence of stage I disease and frequently present with a large pelvic mass. Recurrences are more frequent with this entity than with other types of EOC. The clinical management of advanced EOC includes maximal cytoreduction and platinum plus paclitaxel-based chemotherapy. The survival rates of patients with advanced OCCC are lower than those of patients with advanced serous EOC (serous subtype). The poor response rate to platinum-based regimens may be related to the intrinsic chemoresistance of these tumors. Despite their aggressive clinical course, OCCCs are still treated similarly to the other EOCs at the present time, because the rarity of these tumors prevents the conduction of randomized studies.

CONCLUSION

Novel treatment approaches should be adopted in OCCC. Molecular-targeted therapies and effective new agents without cross-resistance to platinum compounds should be evaluated in a prospective clinical trial in OCCC.

Tissue factor expression as a possible determinant of thromboembolism in ovarian cancer

Ovarian cancer, and clear cell carcinoma in particular, reportedly increases the risk of venous thromboembolism (VTE). However, the mechanisms remain unclear. Tissue factor (TF) supposedly represents a major factor in the procoagulant activities of cancer cells. The present study examined the involvement of TF expression in VTE for patients with ovarian cancer. Subjects comprised 32 consecutive patients (mean age 49.8 years) with histologically confirmed ovarian cancer. Presence of VTE was examined using a combination of clinical features, D-dimer levels and venous ultrasonography. Immunohistochemical analysis was used to evaluate TF expression into 4 degrees. Venous thromboembolism was identified in 10 of the 32 patients (31%), including five of the 11 patients with clear cell carcinoma. Tissue factor expression was detected in cancer tissues from 24 patients and displayed significant correlations with VTE development (P=0.0003), D-dimer concentration (P=0.003) and clear cell carcinoma (P<0.05). Multivariate analysis identified TF expression as an independent predictive factor of VTE development (P<0.05). Tissue factor (TF) expression is a possible determinant of VTE development in ovarian cancer. In particular, clear cell carcinoma may produce excessive levels of TF and is more likely to develop VTE.

Prognosis of ovarian cancer subsequent to venous thromboembolism: a nationwide Danish cohort study

Background

Venous thromboembolism (VTE) is associated with ovarian cancer and may impact the prognosis of ovarian cancer. Our aims were to examine the extent of disease at the time of the diagnosis of ovarian cancer and to estimate the impact of VTE on survival of ovarian cancer.

Methods

We identified 12,835 ovarian cancer patients diagnosed from 1980 to 2003 in the Danish Cancer Registry and obtained information on previous primary VTE diagnosis from the Danish National Hospital Discharge Registry. Ovarian cancer patients with previous VTE related to other cancers, surgery, or pregnancy were excluded. The vital status was determined by linking data to the Civil Registration System.

Results

We identified 50 ovarian cancer patients diagnosed less than 4 months after the VTE and 78 ovarian cancer patients diagnosed more than 4 months after the VTE diagnosis. Advanced stages tended to be more common among patients with VTE. One-year survivals were 44% and 54% among the two VTE groups, compared with 63% among patients without VTE. Adjusted (for age, calendar time, comorbidity, and FIGO-stage) mortality ratios were 1.7 (95% CI = 1.2–2.5) and 1.2 (95% CI = 0.8–1.7), respectively.

Conclusion

Ovarian cancer diagnosed less than four months before VTE is associated with an advanced stage and a poorer prognosis.