Clear cell adenocarcinoma associated with clear cell adenofibromatous components: a subgroup of ovarian clear cell adenocarcinoma with distinct clinicopathologic characteristics

Impact of residual disease as a prognostic factor for survival in women with advanced epithelial ovarian cancer after primary surgery

BACKGROUND

Ovarian cancer is the seventh most common cancer among women and a leading cause of death from gynaecological malignancies. Epithelial ovarian cancer is the most common type, accounting for around 90% of all ovarian cancers. This specific type of ovarian cancer starts in the surface layer covering the ovary or lining of the fallopian tube. Surgery is performed either before chemotherapy (upfront or primary debulking surgery (PDS)) or in the middle of a course of treatment with chemotherapy (neoadjuvant chemotherapy (NACT) and interval debulking surgery (IDS)), with the aim of removing all visible tumour and achieving no macroscopic residual disease (NMRD). The aim of this review is to investigate the prognostic impact of size of residual disease nodules (RD) in women who received upfront or interval cytoreductive surgery for advanced (stage III and IV) epithelial ovarian cancer (EOC).

OBJECTIVES

To assess the prognostic impact of residual disease after primary surgery on survival outcomes for advanced (stage III and IV) epithelial ovarian cancer. In separate analyses, primary surgery included both upfront primary debulking surgery (PDS) followed by adjuvant chemotherapy and neoadjuvant chemotherapy followed by interval debulking surgery (IDS). Each residual disease threshold is considered as a separate prognostic factor.

SEARCH METHODS

We searched CENTRAL (2021, Issue 8), MEDLINE via Ovid (to 30 August 2021) and Embase via Ovid (to 30 August 2021).

SELECTION CRITERIA

We included survival data from studies of at least 100 women with advanced EOC after primary surgery. Residual disease was assessed as a prognostic factor in multivariate prognostic models. We excluded studies that reported fewer than 100 women, women with concurrent malignancies or studies that only reported unadjusted results. Women were included into two distinct groups: those who received PDS followed by platinum-based chemotherapy and those who received IDS, analysed separately. We included studies that reported all RD thresholds after surgery, but the main thresholds of interest were microscopic RD (labelled NMRD), RD 0.1 cm to 1 cm (small-volume residual disease (SVRD)) and RD > 1 cm (large-volume residual disease (LVRD)).

DATA COLLECTION AND ANALYSIS

Two review authors independently abstracted data and assessed risk of bias. Where possible, we synthesised the data in meta-analysis. To assess the adequacy of adjustment factors used in multivariate Cox models, we used the 'adjustment for other prognostic factors' and 'statistical analysis and reporting' domains of the quality in prognosis studies (QUIPS) tool. We also made judgements about the certainty of the evidence for each outcome in the main comparisons, using GRADE. We examined differences between FIGO stages III and IV for different thresholds of RD after primary surgery. We considered factors such as age, grade, length of follow-up, type and experience of surgeon, and type of surgery in the interpretation of any heterogeneity. We also performed sensitivity analyses that distinguished between studies that included NMRD in RD categories of < 1 cm and those that did not. This was applicable to comparisons involving RD < 1 cm with the exception of RD < 1 cm versus NMRD. We evaluated women undergoing PDS and IDS in separate analyses.

MAIN RESULTS

We found 46 studies reporting multivariate prognostic analyses, including RD as a prognostic factor, which met our inclusion criteria: 22,376 women who underwent PDS and 3697 who underwent IDS, all with varying levels of RD. While we identified a range of different RD thresholds, we mainly report on comparisons that are the focus of a key area of clinical uncertainty (involving NMRD, SVRD and LVRD). The comparison involving any visible disease (RD > 0 cm) and NMRD was also important. SVRD versus NMRD in a PDS setting In PDS studies, most showed an increased risk of death in all RD groups when those with macroscopic RD (MRD) were compared to NMRD. Women who had SVRD after PDS had more than twice the risk of death compared to women with NMRD (hazard ratio (HR) 2.03, 95% confidence interval (CI) 1.80 to 2.29; I2 = 50%; 17 studies; 9404 participants; moderate-certainty). The analysis of progression-free survival found that women who had SVRD after PDS had nearly twice the risk of death compared to women with NMRD (HR 1.88, 95% CI 1.63 to 2.16; I2 = 63%; 10 studies; 6596 participants; moderate-certainty). LVRD versus SVRD in a PDS setting When we compared LVRD versus SVRD following surgery, the estimates were attenuated compared to NMRD comparisons. All analyses showed an overall survival benefit in women who had RD < 1 cm after surgery (HR 1.22, 95% CI 1.13 to 1.32; I2 = 0%; 5 studies; 6000 participants; moderate-certainty). The results were robust to analyses of progression-free survival. SVRD and LVRD versus NMRD in an IDS setting The one study that defined the categories as NMRD, SVRD and LVRD showed that women who had SVRD and LVRD after IDS had more than twice the risk of death compared to women who had NMRD (HR 2.09, 95% CI 1.20 to 3.66; 310 participants; I2 = 56%, and HR 2.23, 95% CI 1.49 to 3.34; 343 participants; I2 = 35%; very low-certainty, for SVRD versus NMRD and LVRD versus NMRD, respectively). LVRD versus SVRD + NMRD in an IDS setting Meta-analysis found that women who had LVRD had a greater risk of death and disease progression compared to women who had either SVRD or NMRD (HR 1.60, 95% CI 1.21 to 2.11; 6 studies; 1572 participants; I2 = 58% for overall survival and HR 1.76, 95% CI 1.23 to 2.52; 1145 participants; I2 = 60% for progression-free survival; very low-certainty). However, this result is biased as in all but one study it was not possible to distinguish NMRD within the < 1 cm thresholds. Only one study separated NMRD from SVRD; all others included NMRD in the SVRD group, which may create bias when comparing with LVRD, making interpretation challenging. MRD versus NMRD in an IDS setting Women who had any amount of MRD after IDS had more than twice the risk of death compared to women with NMRD (HR 2.11, 95% CI 1.35 to 3.29, I2 = 81%; 906 participants; very low-certainty).

AUTHORS' CONCLUSIONS

In a PDS setting, there is moderate-certainty evidence that the amount of RD after primary surgery is a prognostic factor for overall and progression-free survival in women with advanced ovarian cancer. We separated our analysis into three distinct categories for the survival outcome including NMRD, SVRD and LVRD. After IDS, there may be only two categories required, although this is based on very low-certainty evidence, as all but one study included NMRD in the SVRD category. The one study that separated NMRD from SVRD showed no improved survival outcome in the SVRD category, compared to LVRD. Further low-certainty evidence also supported restricting to two categories, where women who had any amount of MRD after IDS had a significantly greater risk of death compared to women with NMRD. Therefore, the evidence presented in this review cannot conclude that using three categories applies in an IDS setting (very low-certainty evidence), as was supported for PDS (which has convincing moderate-certainty evidence).

Pathology of Endometrioid and Clear Cell Carcinoma of the Ovary

This review is an appraisal of the current state of knowledge of 2 enigmatic histotypes of ovarian carcinoma: endometrioid and clear cell carcinoma. Both show an association endometriosis and the hereditary nonpolyposis colorectal cancer (Lynch) syndrome, and both typically present at an early stage. Pathologic and immunohistochemical features that distinguish these tumors from high-grade serous carcinomas, each other, and other potential mimics are discussed, as are staging, grading, and molecular pathogenesis.

High Ki-67 expression is significantly associated with poor prognosis of ovarian cancer patients: evidence from a meta-analysis

OBJECTIVE

The prognostic significance of Ki-67 expression in patients with ovarian cancer was controversial in various studies. Therefore, we carried out a meta-analysis to determine the prognostic significance of Ki-67 in ovarian cancer patients.

METHODS

We searched PubMed, Cochrane Library, EMBASE, Web of Knowledge, China National Knowledge Infrastructure database and WanFang digital database for eligible studies from January 1, 1990 to June 1, 2017. The pooled hazard ratios and 95% confidence intervals were calculated to assess the prognostic significance of Ki-67 expression for overall survival in ovarian cancer patients.

RESULTS

Finally, 38 eligible studies and 5004 ovarian cancer patients were included in the current study. The pooled hazard ratio was 1.35 (95% confidence interval 1.24-1.46, P = 0.001) for overall survival in ovarian cancer patients. The funnel plot bias was obviously asymmetrical and Egger's test also detected significant publication bias (P = 0.001). The Contour-enhanced funnel plot with trim-and-fill method supplemented 11 dummy studies to balance the funnel plot and nine new supplementary studies were in area with statistical significance. Sensitivity analysis and cumulative meta-analysis further demonstrated that the association between high Ki-67 expression and poor overall survival of ovarian cancer patients was stable and reliable.

CONCLUSIONS

High Ki-67 expression is significantly related to poor overall survival and may serve as a prognostic biomarker for ovarian cancer patients.

Origins based clinical and molecular complexities of epithelial ovarian cancer

Ovarian cancer is the most lethal of all common gynaecological malignancies in women worldwide. Ovarian cancer comprises of >15 distinct tumor types and subtypes characterized by histopathological features, environmental and genetic risk factors, precursor lesions and molecular events during oncogenesis. Recent studies on gene signature profiling of different subtypes of ovarian cancer have revealed significant genetic heterogeneity between and within each ovarian cancer histological subtype. Thus, an immense interest have shown towards a more personalized medicine for understanding the clinical and molecular complexities of four major types of epithelial ovarian cancer (serous, endometrioid, clear cell, and mucinous). As such, further in depth studies are needed for identification of molecular signalling network complexities associated with effective prognostication and targeted therapies to prevent or treat metastasis. Therefore, understanding the metastatic potential of primary ovarian cancer and therapeutic interventions against lethal ovarian cancer for the development of personalized therapies is very much indispensable. Consequently, in this review we have updated the key dysregulated genes of four major subtypes of epithelial carcinomas. We have also highlighted the recent advances and current challenges in unravelling the complexities of the origin of tumor as well as genetic heterogeneity of ovarian cancer.

Ovarian Clear Cell Adenofibroma of Low Malignant Potential Developing Into Clear Cell Adenocarcinoma

Ovarian clear cell adenofibroma is uncommon, and borderline clear cell adenofibroma (low malignant potential) is extremely rare. Borderline clear cell adenofibromas may represent the precursor lesion of clear cell adenocarcinoma of the ovary, but this has not been established. We present a case of a woman in her mid-50s with a clear cell adenofibroma ranging from benign to borderline to frankly invasive. While some clear cell adenocarcinomas are thought to arise from endometriosis, this range of findings supports the theory that some ovarian clear cell adenocarcinomas originate from borderline tumors.

Endometriosis-associated ovarian neoplasia

This article reviews the most relevant pathological and molecular features of ovarian tumours that are associated with endometriosis. Endometriosis is a common condition, affecting 5-15% of all women, and it has been estimated that 0.5-1% of cases are complicated by neoplasia. The most common malignant tumours in this setting are endometrioid adenocarcinoma and clear cell adenocarcinoma, each accounting for approximately 10% of ovarian carcinomas in Western countries. A minority of cases are associated with Lynch syndrome. These carcinomas are often confined to the ovaries at presentation in which case they have relatively favourable outcomes. However, high-stage tumours, particularly clear cell carcinomas, generally have a poor prognosis and this partly reflects relative resistance to current treatment. Histological diagnosis is straightforward in the majority of cases but some variants, for example endometrioid carcinomas with sex cord-like appearances or oxyphil cells, may create diagnostic difficulty. Similarly, clear cell carcinomas can show a range of architectural and cytological patterns that overlap with other tumours, both primary and metastatic, involving the ovaries. Endometriosis-associated borderline tumours are less common, and they often show mixed patterns of differentiation (seromucinous tumours). Atypical endometriosis may represent an intermediate step in neoplastic progression and some of these lesions demonstrate immunohistological and molecular alterations similar to those observed in endometriosis-related tumours. ARID1A mutations are relatively common in all of these tumours, but each has additional characteristic molecular alterations which are likely to be of increasing clinical relevance as targeted therapies are developed. Less is known of the pathogenesis of rarer endometriosis-associated ovarian tumours including endometrioid stromal sarcoma, mesodermal (Müllerian) adenosarcoma, and carcinosarcoma. This article also briefly reviews the issue of synchronous endometrioid carcinomas of the endometrium and the ovary, including the most recent developments on pathogenesis.

Borderline Clear Cell Adenofibroma of the Ovary

Borderline clear cell tumors are extremely rare, and few cases have been reported in the literature. Herein, we present a case of borderline clear cell adenofibroma of the ovary in a 58-year-old woman who presented with a pelvic mass and constipation. Physical examination revealed a 10 cm solid midline pelvic mass. Computed tomography showed an 8 cm heterogeneous enhancing mass attached to the left posterolateral wall of the uterus. The patient's serum CA 125 levels were slightly elevated (80.9 U/ml). The patient was given a total abdominal hysterectomy with bilateral salpingooophorectomy. On gross examination, it was found that the left ovarian tumor was an 8.0 × 7.5 × 8.0 cm solid multilobulated mass containing tiny cysts. Histologically, the tumor was composed of small glands in dense fibrous and myxoid stroma. The glands were lined with cuboidal cells with clear cytoplasm and mild to moderate nuclear atypia. No stromal invasion was observed. The pathological diagnosis was borderline clear cell adenofibroma of the left ovary. There was no reoccurrence 36 months post operation.

Clear cell carcinoma of the ovary: comparison of MR findings of histological subtypes

PURPOSE

To retrospectively compare the MR findings of histological subtypes of clear cell carcinomas (CCCs) of the ovary.

MATERIALS AND METHODS

This single-center retrospective study was approved by the institutional review board, and the requirement for informed consent was waived. Between April 2005 and August 2015, we found 51 consecutive patients with histopathologically proven CCCs. Among them, 44 CCCs in 37 patients who underwent preoperative MR imaging were included. CCCs were pathologically divided into three subgroups: (1) four clear cell adenofibroma-associated CCCs, (2) 21 endometriosis-associated CCCs, and (3) 19 indeterminate CCCs. The statistical tests were used to compare the frequency of qualitative assessments and value of quantitative measurements among the histological subtypes.

RESULTS

On T2-weighted images, hypointense areas within solid components were more frequently observed in clear cell adenofibroma-associated CCCs [3/4 (75%)] than in the remaining CCCs [1/40 (3%)] (p < 0.01), and the signal intensity ratios (SIRs) of solid components were significantly lower in clear cell adenofibroma-associated CCCs (0.27 ± 0.13) than in the remaining CCCs (0.61 ± 0.18) (p < 0.01). On T1-weighted images, hyperintensities of cystic components were more frequently observed in the endometriosis-associated CCCs [17/21 (81%)] than in the remaining CCCs [5/20 (25%)] (p < 0.01), and the SIRs of cystic components were significantly higher in endometriosis-associated CCCs (2.99 ± 1.51) than in the remaining CCCs (1.82 ± 1.10) (p < 0.01).

CONCLUSION

MR features may help differentiate between adenofibroma-associated and endometriosis-associated CCC.

Possible de novo clear cell carcinoma in the contralateral ovary 9 years after fertility-sparing surgery for Stage IA clear cell ovarian carcinoma

A patient who underwent fertility-sparing surgery for Stage IA clear cell carcinoma may have developed de novo clear cell carcinoma in the contralateral ovary 9 years later. She underwent fertility-sparing surgery and postoperative adjuvant chemotherapy for right ovarian carcinoma at 33 years of age (when endometriosis was observed in the contralateral ovary). At the age of 41 years, a tumor was discovered in the left ovary. This was diagnosed pathologically as clear cell carcinoma with clear cell adenofibroma, which may have developed de novo. A consensus is currently taking shape that although fertility-sparing surgery is a therapeutic option for patients with Stage IA clear cell carcinoma, long-term outpatient monitoring is advised to watch for its recurrence or de novo development in the contralateral ovary.

Effect of ARID1A/BAF250a expression on carcinogenesis and clinicopathological factors in pure-type clear cell adenocarcinoma of the ovary

Frequent mutation of the ARID1A gene has been recently identified in ovarian clear-cell adenocarcinoma (CCA); however, the clinical significance of BAF250a expression encoded by the ARID1A gene remains to be determined. The aim of the present study was to assess whether BAF250a expression had an impact on the clinical features of CCA. A total of 97 cases of CCA treated at a single institution were enrolled in the present study. The tissue samples were evaluated by immunohistochemical staining. BAF250a-deficient expression was observed in 30% (29/97) of all CCA cases. Of this, 19% of non-atypical endometriosis, 26% of atypical endometriosis, 39% of endometriosis-related CCA, 5% of benign clear-cell adenofibroma (CCAF), 5% of borderline CCAF and 10% of CCAF-related CCA. BAF250a-deficient expression was significantly more frequent in endometriosis-related CCA compared with that in CCAF-related CCA (P=0.02). No significant difference was observed in the response rate of primary chemotherapy according to BAF250a expression status (P=0.48). Additionally, BAF250a expression status was not significantly correlated with progression-free and overall survival in patients with CCA. Although loss of BAF250a expression was associated with early tumorigenesis in endometriosis-related CCA, this alteration was not significantly correlated with chemosensitivity and prognoses of CCA. Further biomarker analyses, including BAF250a expression, are required to improve the prognoses of CCA.

Clear Cell Adenocarcinoma Arising from Adenofibroma in a Patient with Endometriosis of the Ovary

Ovarian clear cell adenocarcinomas (CCACs) are frequently associated with endometriosis and, less often with clear cell adenofibromas (CCAFs). We encountered a case of ovarian CCAC arising from benign and borderline adenofibromas of the clear cell and endometrioid types with endometriosis in a 53-year-old woman. Regions of the adenofibromas showed transformation to CCAC and regions of the endometriosis showed atypical endometriotic cysts. This case demonstrates that CCAC can arise from CCAF or endometriosis.

Management and prognosis of clear cell borderline ovarian tumor

BACKGROUND

The clear cell borderline ovarian tumor (CCBOT) of the ovary is a rare tumor accounting for less than 1% of BOT. Fewer than 25 cases have been reported in the literature (including details on clinical management and outcomes). The aim of this study was to determine the prognosis of a series of CCBOTs collected in 2 reference centers.

PATIENTS AND METHODS

This was a retrospective review of patients with CCBOT treated or referred to our institutions. A centralized histological review by a reference pathologist and data on the clinical characteristics, management, and outcomes of patients were required for inclusion.

RESULTS

Twelve patients were identified between 2000 and 2010. The median age of patients was 68 years (range, 36-83 years). Two had been treated conservatively and 9 radically (data unknown in 1). The tumor was unilateral in 11 cases. All patients had stage I disease. All cases were CCBOT with an adenofibromatous pattern. Stromal microinvasion or intraepithelial carcinoma was histologically associated in 2 and 3 cases, respectively. Four of the 12 patients had synchronous endometrial disorders (but no endometrioid carcinoma). No cases were histologically associated with endometriosis. Four patients were lost to follow-up. Among 8 other patients, after a median period of 28 months (range, 2-129 months), no recurrence had occurred (1 patient had died of another disease).

CONCLUSION

Clear cell borderline ovarian tumor carries a good prognosis. All tumors are stage I; therefore, surgical staging is not necessary in most of the cases. Conservative treatment could be proposed to young patients, but uterine curettage would then be required in cases of uterine preservation.

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.

Optimal primary surgical treatment for advanced epithelial ovarian cancer

BACKGROUND

Ovarian cancer is the sixth most common cancer among women. In addition to diagnosis and staging, primary surgery is performed to achieve optimal cytoreduction (surgical efforts aimed at removing the bulk of the tumour) as the amount of residual tumour is one of the most important prognostic factors for survival of women with epithelial ovarian cancer. An optimal outcome of cytoreductive surgery remains a subject of controversy to many practising gynae-oncologists. The Gynaecologic Oncology group (GOG) currently defines 'optimal' as having residual tumour nodules each measuring 1 cm or less in maximum diameter, with complete cytoreduction (microscopic disease) being the ideal surgical outcome. Although the size of residual tumour masses after surgery has been shown to be an important prognostic factor for advanced ovarian cancer, it is unclear whether it is the surgical procedure that is directly responsible for the superior outcome that is associated with less residual disease.

OBJECTIVES

To evaluate the effectiveness and safety of optimal primary cytoreductive surgery for women with surgically staged advanced epithelial ovarian cancer (stages III and IV).To assess the impact of various residual tumour sizes, over a range between zero and 2 cm, on overall survival.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, Issue 3) and the Cochrane Gynaecological Cancer Review Group Trials Register, MEDLINE and EMBASE (up to August 2010). We also searched registers of clinical trials, abstracts of scientific meetings, reference lists of included studies and contacted experts in the field.

SELECTION CRITERIA

Retrospective data on residual disease from randomised controlled trials (RCTs) or prospective and retrospective observational studies which included a multivariate analysis of 100 or more adult women with surgically staged advanced epithelial ovarian cancer and who underwent primary cytoreductive surgery followed by adjuvant platinum-based chemotherapy. We only included studies that defined optimal cytoreduction as surgery leading to residual tumours with a maximum diameter of any threshold up to 2 cm.

DATA COLLECTION AND ANALYSIS

Two review authors independently abstracted data and assessed risk of bias. Where possible, the data were synthesised in a meta-analysis.

MAIN RESULTS

There were no RCTs or prospective non-RCTs identified that were designed to evaluate the effectiveness of surgery when performed as a primary procedure in advanced stage ovarian cancer.We found 11 retrospective studies that included a multivariate analysis that met our inclusion criteria. Analyses showed the prognostic importance of complete cytoreduction, where the residual disease was microscopic that is no visible disease, as overall (OS) and progression-free survival (PFS) were significantly prolonged in these groups of women. PFS was not reported in all of the studies but was sufficiently documented to allow firm conclusions to be drawn.When we compared suboptimal (> 1 cm) versus optimal (< 1 cm) cytoreduction the survival estimates were attenuated but remained statistically significant in favour of the lower volume disease group There was no significant difference in OS and only a borderline difference in PFS when residual disease of > 2 cm and < 2 cm were compared (hazard ratio (HR) 1.65, 95% CI 0.82 to 3.31; and HR 1.27, 95% CI 1.00 to 1.61, P = 0.05 for OS and PFS respectively).There was a high risk of bias due to the retrospective nature of these studies where, despite statistical adjustment for important prognostic factors, selection bias was still likely to be of particular concern.Adverse events, quality of life (QoL) and cost-effectiveness were not reported by treatment arm or to a satisfactory level in any of the studies.

AUTHORS' CONCLUSIONS

During primary surgery for advanced stage epithelial ovarian cancer all attempts should be made to achieve complete cytoreduction. When this is not achievable, the surgical goal should be optimal (< 1 cm) residual disease. Due to the high risk of bias in the current evidence, randomised controlled trials should be performed to determine whether it is the surgical intervention or patient-related and disease-related factors that are associated with the improved survival in these groups of women. The findings of this review that women with residual disease < 1 cm still do better than women with residual disease > 1 cm should prompt the surgical community to retain this category and consider re-defining it as 'near optimal' cytoreduction, reserving the term 'suboptimal' cytoreduction to cases where the residual disease is > 1 cm (optimal/near optimal/suboptimal instead of complete/optimal/suboptimal).

Borderline clear cell adenofibroma with extensive hemorrhagic necrosis

Borderline clear cell adenofibroma of the ovary is rather rare since most of clear cell tumors are carcinomas. We report a case of ovarian borderline clear cell adenofibroma in a 52-year-old postmenopausal woman. The tumor had the characteristic histologic features of borderline clear cell adenofibroma except for central extensive hemorrhagic necrosis. The prognosis of borderline clear cell adenofibroma is excellent. Because the invasiveness cannot be assessed in the necrotic areas, our patient needed long-term follow-up.

Nonserous Ovarian Epithelial Tumors

This review covers the group of relatively uncommon nonserous ovarian epithelial tumors. The authors focus on the group's distinctiveness from the much more common serous tumors and show the similarities across entities. Diagnostic criteria that separate the different entities are currently being debated. Particular problems include the reproducible diagnosis of high-grade endometrioid, transitional cell, mixed epithelial and undifferentiated carcinomas. Furthermore, despite recognition that most malignant mucinous tumors involving ovary represent metastases from extraovarian primary sites, many misdiagnoses still occur. The authors discuss their rationale behind their opinions about these problematic topics.

Pathogenesis of ovarian clear cell adenofibroma, atypical proliferative (borderline) tumor, and carcinoma: clinicopathologic features of tumors with endometriosis or adenofibromatous components support two related pathways of tumor development

The clinicopathologic features of 472 ovarian epithelial clear cell neoplasms (4 adenofibromas [AFs], 41 atypical proliferative [borderline] tumors [APTs], and 427 carcinomas [CAs]) were studied in order to elucidate the morphologic steps involved in the pathogenesis of these tumors and determine whether clear cell CA is a type I or type II tumor in the dualistic model of ovarian carcinogenesis. Thirty-three percent of the CAs had an adenofibromatous background [CA(AF+)], and 67% did not [CA(AF-)]. Endometriosis was found in all types of tumors, but tumors arising in endometriotic cysts were more frequent with CA(AF-)s (p<0.0001). The subset of women with CA(AF-)s with endometriosis were younger (p<0.0001), their tumors were more frequently cystic (p<0.0001), they more commonly had a mixed carcinoma component of non-clear cell type (p=0.006), and they were more frequently oxyphilic (p=0.015) compared with CA(AF+)s. The architecture of the former tumors was more commonly papillary compared to tubulocystic in the latter (p=0.0006). Atypical endometriosis was more common in CA(AF-)s than in AFs, APTs, and CC(AF+)s [p=0.004]. The subset of CA(AF-)s without endometriosis presented more frequently in advanced stage (>I) and were higher grade compared to CA(AF+)s or CA(AF-) with endometriosis (p-values, <0.0001 to 0.0071). All AFs and APTs were stage I compared to 79% of CA(AF+)s. An increase in mean tumor size correlated with each respective tumor category from AF (6.8 cm) to CA(AF+) [12.9 cm]. Notable nuclear atypia was absent in all AFs but was focally present in 27% of APTs and in the adenofibromatous background of 24% of the CA(AF+)s. An increase in the proportion of carcinoma in the CA(AF+)s correlated with an increase in grade and advanced stage. In summary, ovarian clear cell CA appears to develop along two pathways, both of which are related to endometriosis. We speculate that, in one, epithelial atypia arises in an endometriotic cyst and then evolves into clear cell CA, and, in the other, non-cystic endometriosis induces a fibromatous reaction resulting in the formation of AF, which then develops into APT and subsequently a clear cell CA. The absence of endometriosis or adenofibromatous components in CC(AF-)s may be due to overgrowth and obliteration by the invasive carcinoma. Finally, the findings in this study support the view that both types of clear cell CA [CC(AF+) and CC(AF-)] are more closely related to type I tumors.

Ovarian clear cell adenofibromatous tumor of borderline malignancy associated with high levels of carbohydrate antigen 19-9

This report presents a case of ovarian clear cell adenofibromatous tumor of borderline malignancy, which is a rare variant of an ovarian epithelial tumor associated with high levels of carbohydrate antigen 19-9 (CA19-9). A 79-year-old female with a large pelvic tumor underwent a total abdominal hysterectomy and bilateral salpingo-oophorectomy; her pre-operative serum CA19-9 level was 780 IU/mL. The diameter of the elastic hard ovarian tumor was 17 cm. Microscopically, many tubular glands lay in an abundant fibrocollagenous stroma. Most of the glands were lined with flattened cells or cuboidal clear cells with large nuclei, but in a small area there were small crowded glands. The epithelium of the glands, in which stratification occurred over three layers, had clear cytoplasmic regions and enlarged nuclei with prominent nucleoli. CA19-9 was immunohistochemically positive in the epithelial cells. The final diagnosis was ovarian clear cell adenofibromatous tumor of borderline malignancy, stage Ia. Postoperatively, her serum CA19-9 level decreased to the normal limit.

The role of hepatocyte nuclear factor-1beta in the pathogenesis of clear cell carcinoma of the ovary

PROBLEM

Clear cell carcinoma (CCC) of the ovary has a number of features distinguishing it from other epithelial ovarian carcinomas (EOC) because of its characteristic histology and biology, frequent concurrence with endometriotic lesion, and highly chemoresistant nature resulting in an extremely poor prognosis. The incidence of CCC has been steadily increasing in Japan. They comprise approximately 20% of all EOC. Understanding the mechanisms of CCC development and elucidating pathogenesis and pathophysiology are intrinsic to prevention and effective therapies for CCC.

METHOD OF STUDY

This article reviews the English language literature for biology, pathogenesis, and pathophysiological studies on endometriosis-associated EOC. Several data are discussed in the context of endometriosis and CCC biology.

RESULTS

Recent studies based on genome-wide expression analysis technology have noted specific expression of hepatocyte nuclear factor-1beta (HNF-1beta) in endometriosis and CCC, suggesting that early differentiation into the clear cell lineage takes place in the endometriosis. The HNF-1beta-dependent pathway of CCC will be discussed, which are providing new insights into regulation of apoptosis and glycogen synthesis and resistance of CCC to anticancer agents.

CONCLUSIONS

This review summarizes recent advances in the HNF-1beta and its target genes; the potential challenges to the understanding of carcinogenesis, pathogenesis, and pathophysiology of CCC; and a possible novel model is proposed.

An allelotype analysis indicating the presence of two distinct ovarian clear-cell carcinogenic pathways: endometriosis-associated pathway vs. clear-cell adenofibroma-associated pathway

Patterns of allele loss (loss of heterozygosity (LOH)) were studied to identify the genetic backgrounds underlying the two putative carcinogenic pathways of ovarian clear-cell adenocarcinoma: carcinomas thought to arise in endometriosis (endometriosis-associated carcinomas, 20 cases) and carcinomas thought to be derived from clear-cell adenofibroma ((CCAF)-associated carcinomas, 14 cases). Each tumor was assessed for LOH at 24 polymorphic loci located on 12 chromosomal arms: 1p, 3p, 5q, 8p, 9p, 10q, 11q, 13q, 17p, 17q, 19p, and 22q. For all informative loci, the frequency of LOH was not statistically different between the two carcinoma groups: 38% (66/172 loci) in the endometriosis-associated carcinomas and 35% (40/113 loci) in the CCAF-associated carcinomas. In the endometriosis-associated carcinomas, LOH was detected at high frequencies (>50%) at 3p, 5q, and 11q and at low frequencies (<20%) at 8p, 13q, and 17p. In the CCAF-associated carcinomas, LOH was detected at high frequencies at 1p, 10q, and 13q and at low frequencies at 3p, 9p, 11q, and 17q. The frequencies of LOH at chromosomes 3p, 5q, and 11q were significantly higher in the endometriosis-associated carcinomas than in the CCAF-associated carcinomas (P = 0.026, 0.007, and 0.011, respectively). Immunohistochemical analysis demonstrated a close association between the allelic status of the 3p25-26 locus and levels of von Hippel-Lindau (VHL) protein expression (P = 0.0026). These data further support the presence of two distinct carcinogenic pathways to ovarian clear-cell adenocarcinoma; the allelic status of the 3p, 5q, and 11q loci may provide a means to identify the precursor lesions of these carcinomas.

Cystic and adenofibromatous clear cell carcinomas of the ovary: distinctive tumors that differ in their pathogenesis and behavior: a clinicopathologic analysis of 122 cases

Ovarian clear cell carcinomas (CCC) typically present as large adnexal, stage I tumors and are generally considered highly malignant. They are frequently associated with endometriosis and, less often with clear cell adenofibromas. We hypothesized that CCCs are a heterogeneous group of tumors, some arising from a cyst and others from an adenofibroma. To test this hypothesis, 122 cases of CCC were retrieved from the surgical pathology files of National Taiwan University Hospital (74), The Johns Hopkins Hospital (23), and Serei Mikatahara General Hospital (23) (1985 to 2006). Cases were divided into 3 subgroups: (1) cystic, (2) adenofibromatous, and (3) indeterminate. Various features were analyzed including: age, race, laterality, tumor size, architectural pattern (papillary, tubulo-cystic, solid, mixed patterns), grade, mitotic index, association with endometriosis including atypical endometriosis/intraepithelial carcinoma, stage and survival. Nearly 70% of all the patients were diagnosed as stage I. The 2-year and 5-year survival (all stages) was 78% and 68%, respectively. Striking clinicopathologic differences were observed between cystic and adenofibromatous CCCs. Cystic CCC was more frequently diagnosed as stage I compared with adenofibromatous CCC (75% vs. 44%). Conversely, adenofibromatous CCCs were diagnosed more often in advanced stages (stages II-IV) compared with cystic CCCs (56% vs. 18%). Both the cystic and adenofibromatous CCC forms were associated with endometriosis and atypical endometriosis/intraepithelial carcinoma, but the frequency was much higher in the cystic group. Specifically, endometriosis was found in 91% of cystic CCCs and atypical endometriosis/intraepithelial carcinoma in 62% of these cases, whereas endometriosis was found in 44% of adenofibromatous CCCs and atypical endometriosis/intraepithelial carcinoma in 11% of cases. A predominantly papillary pattern was seen in 47% of cystic CCCs, whereas none of the adenofibromatous carcinomas displayed a predominantly papillary pattern. A more favorable outcome was observed for cystic CCCs compared with adenofibromatous CCCs (all stages) which was accounted for by the high proportion of stage I tumors. The 2-year and 5-year survival for the cystic CCCs was 82% and 77% and for the adenofibromatous CCCs (all stages), 62% and 37%, respectively. In summary, subdividing ovarian CCCs into cystic and adenofibromatous CCC reveals differences in a number of clinicopathologic features including their association with endometriosis, histologic patterns, stage distribution, and clinical behavior. Because there were a relatively small number of adenofibromatous CCCs in this series, additional cases must be studied to confirm these findings.

Hobnail-like cells in serous borderline tumor do not represent concomitant incipient clear cell neoplasms

Hobnail-like cells, which suggest a diagnosis of clear cell carcinoma, are also focally observed in serous borderline tumor of the ovary, causing diagnostic confusion. However, the precise nature of hobnail-like cells in serous borderline tumor has not been well characterized. The purpose of this study was to clarify whether or not hobnail-like cells in serous borderline tumor represent concomitant incipient clear cell neoplasms. First, we carefully reviewed hematoxylin and eosin slides taken from 115 ovarian tumors diagnosed as clear cell carcinoma (73 cases), mixed adenocarcinoma containing clear cell carcinoma (5 cases), and serous borderline tumor (37 cases) to clarify the frequency of coexistence of typical clear cell carcinoma and serous borderline tumor. Through the hematoxylin and eosin review, we paid special attention to the cytologic features of hobnail-like cells in serous borderline tumor and serous borderline tumor-like papillary areas in clear cell carcinoma. Second, we selected 19 serous borderline tumors and 16 clear cell carcinomas, in which hobnail-like cells were easily recognizable, and investigated the immunohistochemical expression of estrogen receptor and Wilms tumor gene protein. No coexistence of clear cell carcinoma and serous borderline tumor was evident in any of the above 115 ovarian tumors. Hobnail-like cells were focally positive for estrogen receptor and Wilms tumor gene protein in nearly all serous borderline tumors. Hobnail-like cells in all clear cell carcinomas were completely negative for estrogen receptor and Wilms tumor gene protein, although estrogen receptor expression was very focally observed (less than 5% area) in non-hobnail cells of only one clear cell carcinoma. In conclusion, hobnail-like cells in serous borderline tumor do not represent concomitant incipient clear cell neoplasms because (1) clear cell carcinoma and serous borderline tumor do not coexist and (2) hobnail-like cells in clear cell carcinoma and serous borderline tumor are immunophenotypically distinct. Recognition of our conclusion may protect a patient with "conspicuous hobnail-like cells in serous borderline tumor" from an erroneous overdiagnosis of "concomitant clear cell carcinoma admixed with serous borderline tumor."

A limited panel of immunomarkers can reliably distinguish between clear cell and high-grade serous carcinoma of the ovary

The distinction of ovarian clear cell carcinomas (CCCs) from high-grade serous carcinomas (HG-SCs) is sometimes a diagnostic challenge. With the recognition that CCCs respond poorly to conventional chemotherapy there are efforts to initiate clinical trials for CCC, making accurate diagnosis critical. The purpose of this study was to test and validate a set of antibodies that could aid in the diagnosis of CCC, using a series of cases from different centers in North America. Using a test set of 133 CCCs, we identified the following markers: Cyclin E, estrogen receptor, hepatocyte nuclear factor (HNF)-1beta, Ki-67, p21, p53, and Wilms tumor (WT)1 that show significant discrimination from 200 HG-SCs. For validation, these markers were characterized on an independent set of 104 CCCs from 3 other centers. There were no significant differences in expression of these 7 markers between the independent test and validation sets of CCC. Combining all CCC cases (N=237), HNF-1beta showed the highest sensitivity (82.5%) and specificity (95.2%) for CCC, and WT1 for HG-SC (sensitivity: 79.9%, specificity: 97.4%). A diagnostic panel consisting of WT1, ER, and HNF-1beta demonstrated nearly identical performance as a panel using all 7 markers in distinguishing CCCs from HG-SCs, correctly classifying 84% of cases. Three percent of cases were misclassified and 13% carried an uninformative triple negative immunophenotype. CCCs show a distinct, reproducible immunophenotype, compared with HG-SCs, and a panel of 3 immunomarkers can serve as a diagnostic aid in problematic cases.

Ovarian carcinoma subtypes are different diseases: implications for biomarker studies

BACKGROUND

Although it has long been appreciated that ovarian carcinoma subtypes (serous, clear cell, endometrioid, and mucinous) are associated with different natural histories, most ovarian carcinoma biomarker studies and current treatment protocols for women with this disease are not subtype specific. With the emergence of high-throughput molecular techniques, distinct pathogenetic pathways have been identified in these subtypes. We examined variation in biomarker expression rates between subtypes, and how this influences correlations between biomarker expression and stage at diagnosis or prognosis.

METHODS AND FINDINGS

In this retrospective study we assessed the protein expression of 21 candidate tissue-based biomarkers (CA125, CRABP-II, EpCam, ER, F-Spondin, HE4, IGF2, K-Cadherin, Ki-67, KISS1, Matriptase, Mesothelin, MIF, MMP7, p21, p53, PAX8, PR, SLPI, TROP2, WT1) in a population-based cohort of 500 ovarian carcinomas that was collected over the period from 1984 to 2000. The expression of 20 of the 21 biomarkers differs significantly between subtypes, but does not vary across stage within each subtype. Survival analyses show that nine of the 21 biomarkers are prognostic indicators in the entire cohort but when analyzed by subtype only three remain prognostic indicators in the high-grade serous and none in the clear cell subtype. For example, tumor proliferation, as assessed by Ki-67 staining, varies markedly between different subtypes and is an unfavourable prognostic marker in the entire cohort (risk ratio [RR] 1.7, 95% confidence interval [CI] 1.2%-2.4%) but is not of prognostic significance within any subtype. Prognostic associations can even show an inverse correlation within the entire cohort, when compared to a specific subtype. For example, WT1 is more frequently expressed in high-grade serous carcinomas, an aggressive subtype, and is an unfavourable prognostic marker within the entire cohort of ovarian carcinomas (RR 1.7, 95% CI 1.2%-2.3%), but is a favourable prognostic marker within the high-grade serous subtype (RR 0.5, 95% CI 0.3%-0.8%).

CONCLUSIONS

The association of biomarker expression with survival varies substantially between subtypes, and can easily be overlooked in whole cohort analyses. To avoid this effect, each subtype within a cohort should be analyzed discretely. Ovarian carcinoma subtypes are different diseases, and these differences should be reflected in clinical research study design and ultimately in the management of ovarian carcinoma.

Clear-cell adenofibroma can be a clonal precursor for clear-cell adenocarcinoma of the ovary: a possible alternative ovarian clear-cell carcinogenic pathway

Several studies have reported that ovarian clear-cell adenocarcinoma can be derived from endometriosis. Although the clear-cell adenofibroma (CCAF), a major form of benign and borderline ovarian clear-cell tumour, has been suggested as another precursor for clear-cell adenocarcinoma (CCA), there is no supportive genetic evidence for this presumption. To examine the genetic linkage between CCAF and CCA of the ovary, we conducted allelotype analysis for both CCAF and adjacent CCA components in 14 cases of CCA associated with benign CCAF and/or borderline CCAF. DNA isolated from laser-microdissected tissue was subjected to polymerase chain reaction and analysis for loss of heterozygosity (LOH), using 17 polymorphic markers located on 11 chromosomal arms: 1p, 5q, 8p, 9p, 9q, 10q, 11q, 13q, 18q, 19p and 22q. For all informative loci, the frequency of LOH in adenocarcinoma was 49% (54/110 loci), and was significantly higher than those in the components of benign CCAF (22%, 20/92 loci) and borderline CCAF (30%, 25/83 loci) (chi(2) test; p<0.05, respectively). The concordance rate in allelic patterns at all informative loci was 74% between benign CCAF and adenocarcinoma components, 81% between borderline CCAF and adenocarcinoma components, and 95% between benign CCAF and borderline CCAF components. Furthermore, between CCAF and adenocarcinoma components, an identical LOH pattern, involving the same alleles, was found in 13 (93%) of 14 cases at one or more chromosomal loci, and estimation of probability indicated that these events were very unlikely to have occurred by chance. Among the markers examined, LOHs on 5q, 10q and 22q were frequent in both CCAF and adenocarcinoma components, whereas LOHs on 1p and 13q were rare in CCAF components but frequent in adenocarcinoma components. These findings suggest that CCAF can be a clonal precursor for ovarian clear-cell adenocarcinoma.

Expression of platelet-derived growth factors and their receptors in ovarian clear-cell carcinoma and its putative precursors

Recent studies have shown that platelet-derived growth factors and their receptors are frequently co-expressed in ovarian cancers. Herein, we investigated the role of the platelet-derived growth factor pathway in the development of ovarian clear-cell adenocarcinoma, a highly chemoresistant form of ovarian cancer. Immunohistochemical expression of platelet-derived growth factor receptor-alpha and receptor-beta, platelet-derived growth factor A-chain and B-chain was examined in 31 cases of clear-cell adenocarcinoma and 56 coexisting putative precursor lesions: 17 non-atypical and 19 atypical endometrioses, and 10 non-atypical and 10 atypical clear-cell adenofibroma components. Twenty-one solitary endometrioses were also examined. Vascular endothelial cells were always positive for all the markers examined, and were used as positive controls. The frequencies of positivity for platelet-derived growth factor receptor-alpha and receptor-beta, and platelet-derived growth factor A-chain increased in accordance with higher cytologic atypia in the putative precursors: 71, 47, and 59% in the 17 non-atypical endometrioses, 84, 73, and 84% in the 19 atypical endometrioses, 0% each in the 10 non-atypical clear-cell adenofibromas, 100, 90, and 90% in the 10 atypical clear-cell adenofibromas, and 97, 97, and 100% in the 31 clear-cell adenocarcinomas, respectively. Positivity for platelet-derived growth factor B-chain increased in accordance with increased atypia in clear-cell adenofibroma: 0% in non-atypical clear-cell adenofibromas, 30% in atypical clear-cell adenofibromas, and 60% in coexisting carcinomas. However, in contrast, positivity for platelet-derived growth factor B-chain decreased in accordance with increased atypia in endometriosis coexisting with clear-cell adenocarcinomas: 35% in non-atypical endometrioses, 11% in atypical endometrioses, and 5% in coexisting carcinomas. Platelet-derived growth factor receptor-alpha and receptor-beta, and their ligands A-chain and B-chain were positive in 14, 29, 19, and 62% of the solitary endometrioses, respectively. These results indicate activation of the platelet-derived growth factor pathway in ovarian clear-cell adenocarcinomas and suggest biological differences between carcinomas that arise in association with clear-cell adenofibroma vs endometriosis.