Trends and characteristics of epithelial ovarian cancer in Japan between 2002 and 2015: A JSGO-JSOG joint study

Targeting DNA Damage Response Pathway in Ovarian Clear Cell Carcinoma

Ovarian clear cell carcinoma (OCCC) is one of the major types of ovarian cancer and is of higher relative prevalence in Asians. It also shows higher possibility of resistance to cisplatin-based chemotherapy leading to poor prognosis. This may be attributed to the relative lack of mutations and aberrations in homologous recombination-associated genes, which are crucial in DNA damage response (DDR), such as BRCA1, BRCA2, p53, RAD51, and genes in the Fanconi anemia pathway. On the other hand, OCCC is characterized by a number of genetic defects rendering it vulnerable to DDR-targeting therapy, which is emerging as a potent treatment strategy for various cancer types. Mutations of ARID1A, PIK3CA, PTEN, and catenin beta 1 (CTNNB1), as well as overexpression of transcription factor hepatocyte nuclear factor-1β (HNF-1β), and microsatellite instability are common in OCCC. Of particular note is the loss-of-function mutations in ARID1A, which is found in approximately 50% of OCCC. ARID1A is crucial for processing of DNA double-strand break (DSB) and for sustaining DNA damage signaling, rendering ARID1A-deficient cells prone to impaired DNA damage checkpoint regulation and hence sensitive to poly ADP ribose polymerase (PARP) inhibitors. However, while preclinical studies have demonstrated the possibility to exploit DDR deficiency in OCCC for therapeutic purpose, progress in clinical application is lagging. In this review, we will recapitulate the preclinical studies supporting the potential of DDR targeting in OCCC treatment, with emphasis on the role of ARID1A in DDR. Companion diagnostic tests (CDx) for predicting susceptibility to PARP inhibitors are rapidly being developed for solid tumors including ovarian cancers and may readily be applicable on OCCC. The potential of various available DDR-targeting drugs for treating OCCC by drawing analogies with other solid tumors sharing similar genetic characteristics with OCCC will also be discussed.

The post-progression survival of patients with recurrent or persistent ovarian clear cell carcinoma: results from a randomized phase III study in JGOG3017/GCIG

OBJECTIVE

In this study we sought to investigate the clinical factors that affect post-progression survival (PPS) in patients with recurrent or persistent clear cell carcinoma (CCC). We utilized the JGOG3017/Gynecological Cancer InterGroup data to compare paclitaxel plus carboplatin (TC) and irinotecan plus cisplatin (CPT-P) in the treatment of stages I to IV CCC.

METHODS

We enrolled 166 patients with recurrent or persistent CCC and assessed the impact of variables, including platinum sensitivity, treatment arm, crossover chemotherapy, primary stage, residual tumor at primary surgery, performance status, ethnicity, and tumor reduction surgery at recurrence on the median of PPS in patients with recurrent or persistent CCC.

RESULTS

A total of 77 patients received TC, and 89 patients received CPT-P. The median PPS for patients with platinum-resistant disease was 10.9 months, compared with 18.8 months for patients with platinum-sensitive disease (hazard ratio [HR]=1.88; 95% confidence interval [CI]=1.30-2.72; log-rank p<0.001). In the multivariate analysis, the platinum sensitivity (resistant vs. sensitivity; HR=1.60; p=0.027) and primary stage (p=0.009) were identified as independent predictors of prognosis factors for PPS in recurrent or persistent CCC.

CONCLUSIONS

Our findings revealed that platinum sensitivity and primary stage are clinical factors that significantly affect PPS in patients with recurrent or persistent CCC as well as other histologic subtypes of ovarian cancer. PPS in patients with recurrent CCC should establish the basis for future clinical trials in this population.

Distinct transcriptional programs stratify ovarian cancer cell lines into the five major histological subtypes

BACKGROUND

Epithelial ovarian cancer (OC) is a heterogenous disease consisting of five major histologically distinct subtypes: high-grade serous (HGSOC), low-grade serous (LGSOC), endometrioid (ENOC), clear cell (CCOC) and mucinous (MOC). Although HGSOC is the most prevalent subtype, representing 70-80% of cases, a 2013 landmark study by Domcke et al. found that the most frequently used OC cell lines are not molecularly representative of this subtype. This raises the question, if not HGSOC, from which subtype do these cell lines derive? Indeed, non-HGSOC subtypes often respond poorly to chemotherapy; therefore, representative models are imperative for developing new targeted therapeutics.

METHODS

Non-negative matrix factorisation (NMF) was applied to transcriptomic data from 44 OC cell lines in the Cancer Cell Line Encyclopedia, assessing the quality of clustering into 2-10 groups. Epithelial OC subtypes were assigned to cell lines optimally clustered into five transcriptionally distinct classes, confirmed by integration with subtype-specific mutations. A transcriptional subtype classifier was then developed by trialling three machine learning algorithms using subtype-specific metagenes defined by NMF. The ability of classifiers to predict subtype was tested using RNA sequencing of a living biobank of patient-derived OC models.

RESULTS

Application of NMF optimally clustered the 44 cell lines into five transcriptionally distinct groups. Close inspection of orthogonal datasets revealed this five-cluster delineation corresponds to the five major OC subtypes. This NMF-based classification validates the Domcke et al. analysis, in identifying lines most representative of HGSOC, and additionally identifies models representing the four other subtypes. However, NMF of the cell lines into two clusters did not align with the dualistic model of OC and suggests this classification is an oversimplification. Subtype designation of patient-derived models by a random forest transcriptional classifier aligned with prior diagnosis in 76% of unambiguous cases. In cases where there was disagreement, this often indicated potential alternative diagnosis, supported by a review of histological, molecular and clinical features.

CONCLUSIONS

This robust classification informs the selection of the most appropriate models for all five histotypes. Following further refinement on larger training cohorts, the transcriptional classification may represent a useful tool to support the classification of new model systems of OC subtypes.

A CLEARER VIEW ON OVARIAN CLEAR CELL CARCINOMA

Introduction: Ovarian clear cell carcinoma (OCCC) is a less common subtype accounting for approximately 5% of all epithelial ovarian cancers (EOCs). Clinical experience and research findings confirm the remarkable differences in clinical behavior, molecular alterations and pathogenesis of OCCC. The diagnosis of OCCC is typically set at a younger age, and earlier stage and in a background of endometriosis.Results: Molecularly, OCCCs rarely harbor BRCA1/BRCA2 mutations and have fewer copy number variants (CNVs). The most common molecular changes occur in the SWI/SNF chromatin remodeling complex genes, the PI3K/AKT signaling pathway and the receptor tyrosine kinase (RTK)/Ras signaling pathway.Five-year disease-specific survival of patients with OCCC is worse compared to high grade serous carcinomas (HGSOC). The current treatment options for OCCC are based on studies that included patients with predominantly HGSOC and only a minor proportion of cancers with clear cell histology. In order to improve outcomes for patients with OCCC, research should be specific for this subtype.Discussion: As the available information about the specific characteristics of OCCC is increasing, especially at a molecular level, it should be possible to continuously improve the specific diagnostics and treatment. Since OCCC is so rare, it is essential to collect new evidence at an international level. To avoid extrapolation from EOC trials with possible erroneous conclusions, patients should always be encouraged to participate in specific histological trials and basket trials, while paying extra attention to OCCC-like subtypes.

Intratumoural Budding is Associated with Poor Clinical Outcome in Early-Stage Clear Cell Carcinoma of Ovary

AIMS

Clear cell carcinoma of ovary (CCC) is considered a high-grade malignancy by default and the role of histological grading for assessing clinical outcome is not established. We aimed to evaluate histopathological features associated with clinical outcome in CCC patients. Seventy-six cases of CCC with available clinical follow-up information were studied. Histopathological features including tumour size, architectural patterns, nuclear atypia, mitotic activity, intraumoural and peritumoral inflammation, presence of endometriosis, peritumoural and intratumoural budding were evaluated. Multivariate analysis was performed with logistic regression and Kaplan-Meier survival curves with log rank test were used for survival analysis.

METHODS AND RESULTS

Forty cases (53%) presented at stage I. Complete response to treatment was achieved in 65%, while 35% of patients had tumor recurrence or progression of disease despite treatment. At last follow-up, 13% had died of disease, 20% were alive with disease and 67% had no evidence of disease. Higher stage (p=0.0016) and presence of intratumoural budding (p=0.0454) were independently associated with recurrence/disease progression. Advanced stage (p=0.0011), presence of lymph node involvement (p=0.0003), intratumoural budding (p=0.0023) and peritumoural budding (p=0.0334) were significantly associated with shorter survival. Intratumoural budding was significantly associated with recurrent/progressive disease (p=0.0195) and shorter survival (p=0.0277) within the cohort of low-stage (I/II) patients as well.

CONCLUSIONS

We have shown that besides the classic prognostic factors of stage and lymph node status, presence of tumour budding is associated with poorer outcome in patients with CCC. Specifically, evaluation of intratumoural budding may help to better predict prognosis in patients with early-stage disease.

Immunochemical analysis of iron transporters and M2 macrophages in ovarian endometrioma and clear cell adenocarcinoma

The association between iron ions and endometriosis-associated ovarian cancer (EAOC) has been previously investigated to elucidate EAOC carcinogenesis; however, the dynamics of iron deposition in the endometrial epithelium and endometrial stroma of ovarian endometrioma (OE) remains unknown. The present study aimed to determine the expression of iron transporters on the cell surface and the distribution of tumor-associated macrophages (TAMs) englobed with iron in the endometrial stroma. The current retrospective study investigated 20 OE and 18 ovarian clear cell adenocarcinoma (CCC) samples, using Perls Prussian blue staining and immunohistochemistry of iron transporters, including divalent metal transporter 1 (DMT1), transferrin receptor (TfR) and ferroportin (FPN). Additionally, samples were stained for CD68, CD11c, CD163 and CD206, and double-immunostained for iron and CD163 to define the distribution of macrophages. Iron transporters were identified on the endometrial epithelium of OE and CCC tumor cells, and TAMs were englobed with iron in the endometrial stroma of OE and CCC. Histological findings revealed DMT1 upregulation in OE and CCC, whereas lower TfR and FPN expression was observed in OE than in CCC. M2 macrophages were englobed with iron ions in the deep layers of the OE and CCC stroma. The endometrial epithelium located in the endometrial stroma of one patient with OE and the endometrial epithelium adjacent to CCC in two patients with CCC stained positive for the tumor proliferation marker Ki67. Epithelium infiltrating the stroma of OE may become the origin of cancer under the influence of M2 macrophages englobed with iron. These findings provide new perspectives on the malignant transformation of OE into EAOC and its possibility as a precancerous index.

A nomogram to predict the cancer-specific survival of stage II-IV Epithelial ovarian cancer after bulking surgery and chemotherapy

Objective

In order to predict the survival rate of ovarian cancer patients, multiple independent risk factors are integrated to establish a prognostic nomogram.

Methods

Cox analysis was used to construct the nomogram. All of the mainly independent factors, which can be used to predict 3‐year and 5‐year survival rates for cancer in the training cohort, were incorporated to establish nomograms. The C‐index, operating characteristic, ROC curves, and calibration plots can show evaluation results of performance.

Results

Model derivation was based on 3277 patients who belong to different races. The best threshold for age was 51, 59, and 67 year old and the older the people, the worse their survival. Meanwhile, many lymph node examinations indicated a favorable survival and the survival of the positive set was worse than of that. In addition, the optional threshold was 64 mm for tumor size and the set larger than 64 mm had a better survival than that less than 64 mm. Univariate Cox proportional hazards regression model showed that the similar worse outcomes were showed in black race, advanced grade, stage T3, stage M1, lymph nodes positive, and CA125 positive compared with the first group. We found that the number of lymph nodes examined and tumor size had an inverse relationship with its corresponding score of CSS in training cases with bulking surgery and chemotherapy.

Conclusions

We developed a model which relatively accurately predicted the prognosis of ovarian cancer by multiple univariate analysis, at the same time, the proposed nomograms exhibit superior prognostic discrimination and survival prediction.

Analytical validation of human epidermal growth factor receptor 2 immunohistochemistry by the use of the A0485 antibody versus the 4B5 antibody and breast versus gastric scoring guidelines in ovarian clear cell carcinoma

AIMS

The aim of this study was to evaluate human epidermal growth factor receptor 2 (HER2) immunohistochemistry (IHC) in ovarian clear cell carcinoma (OCCC) by using two antibodies and two scoring guidelines in correlation with HER2 amplification and clinicopathological features.

METHODS AND RESULTS

A tissue microarray was constructed by use of a total of 71 OCCC cases for IHC (the A0485 antibody and the 4B5 antibody) and dual-colour silver in-situ hybridisation (DISH). Two pathologists independently scored the IHC according to the 2018 American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) breast cancer guidelines (breast guidelines) and the 2016 ASCO/CAP gastro-oesophageal adenocarcinoma guidelines (gastric guidelines). IHC concordances between A0485 and 4B5 were 87.3-93.0%. Three to 16 (4.2-22.5%) cases had an IHC score of 2+/3+ with frequent basolateral/lateral membranous staining. The 4B5 antibody yielded fewer IHC 2+ cases than the A0485 antibody (n = 2-6 versus n = 5-12). Five (7.0%) cases had HER2 amplification as determined with DISH. Cases with papillary-predominant growth patterns were significantly more likely to have HER2 amplification (P = 0.0051). In predicting DISH results, IHC scored according to the gastric guidelines yielded 100%/100% sensitivity and 83.3-95.5%/98.2-100% specificity, and IHC scored according to the breast guidelines yielded 60-80%/33.3-66.7% sensitivity and 95.5-100%/100% specificity (including/excluding IHC 2+ cases). One case had intratumoral heterogeneity, with discordant results between primary and metastatic tumour specimens.

CONCLUSION

We demonstrated HER2 amplification in 7% of OCCC cases, and the molecular change is significantly associated with papillary-predominant growth patterns. In predicting HER2 amplification, a combination of 4B5 IHC and gastric guidelines provides the best sensitivity and fewer equivocal (IHC 2+) cases. Given the intratumoral heterogeneity, assessment of HER2 status on whole tissue sections and on both primary and metastatic tumour specimens is recommended.

Validation of tissue factor pathway inhibitor 2 as a specific biomarker for preoperative prediction of clear cell carcinoma of the ovary

BACKGROUND

Tissue factor pathway inhibitor 2 (TFPI2) is a novel serum biomarker that discriminates ovarian clear cell carcinoma (CCC) from borderline ovarian tumors (BOTs) and non-clear cell epithelial ovarian cancers (EOCs). Here, we examined the performance of TFPI2 for preoperative diagnosis of CCC.

METHODS

Serum samples were obtained preoperatively from patients with ovarian masses, who needed surgical treatment at five hospitals in Japan. The diagnostic powers of TFPI2 and cancer antigen 125 (CA125) serum levels to discriminate CCC from BOTs, other EOCs, and benign lesions were compared.

RESULTS

A total of 351 patients including 69 CCCs were analyzed. Serum TFPI2 levels were significantly higher in CCC patients (mean ± SD, 508.2 ± 812.0 pg/mL) than in patients with benign lesions (154.7 ± 46.5), BOTs (181 ± 95.5) and other EOCs (265.4 ± 289.1). TFPI2 had a high diagnostic specificity for CCC (79.5%). In patients with benign ovarian endometriosis, no patient was positive for TFPI2, but 71.4% (15/21) were CA125 positive. TFPI2 showed good performance in discriminating stage II-IV CCC from BOTs and other EOCs (AUC 0.815 for TFPI2 versus 0.505 for CA125) or endometriosis (AUC 0.957 for TFPI2 versus 0.748 for CA125). The diagnostic sensitivity of TFPI2 to discriminate CCC from BOTs and other EOCs was improved from 43.5 to 71.0% when combined with CA125.

CONCLUSIONS

High specificity of TFPI2 for preoperative detection of CCC was verified with the defined cutoff level of TFPI2 in clinical practice. TFPI2 and CA125 may contribute substantially to precise prediction of intractable CCC.

Ovarian endometrioid carcinoma and clear cell carcinoma: A 21-year retrospective study

Objective

This study aimed to identify the clinical characteristics of Chinese patients with ovarian endometrioid carcinoma (EC) and clear cell carcinoma (CCC) and to assess the impact of concurrent endometriosis on this group.

Methods

The present study reviewed the medical records of patients who received initial treatment and a postoperative pathological diagnosis of EC or CCC at our center in China between 1998 and 2018.

Results

Of 211 patients, 73 had pure EC, and 91 had pure CCC, and the remaining 47 had mixed cancer. The proportion of EC and CCC remained stable over past 21 years. The proportion of EC declined with aging and the age of EC onset to incline to the young. And the age of CCC onset had two peaks, namely, 36 and 77 years. After review by the pathologist, the number of endometriosis cases found in the pathological section of the analysis increased to 114, accounting for 54% of patients. As the stage progressed, the appearance of endometriosis became increasingly scarce in pathological sections(p = 0.001).

Compared with CCC, EC had a higher frequency of concurrent endometrial cancer (independent endometrial lesions) and estrogen and progesterone receptor expression(p = 0.000). And more patients were in premenopausal state in EC group(p = 0.040).

In the pure group, multivariate analysis showed that correlation existed between relevance to endometriosis and worse outcomes(p = 0.041). In patients with mixed cancer, mixed endometrioid histology was associated with better survival than other subtypes, even with stage III or poorly differentiated tumors(p = 0.001).

Conclusions

CCC and EC which are common in ovarian cancer patients who have associated with endometriosis have distinct clinicopathological characteristics. Attention should be paid to ovarian cancer patients with a history of endometriosis and those with concurrent endometriosis in pathological sections.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13048-021-00804-1.

Treatment Strategies for ARID1A-Deficient Ovarian Clear Cell Carcinoma

Ovarian clear cell carcinoma (OCCC) is a histological subtype of ovarian cancer that is more frequent in Asian countries (~25% of ovarian cancers) than in US/European countries (less than 10%). OCCC is refractory to conventional platinum-based chemotherapy, which is effective against high-grade serous carcinoma (HGSC), a major histological subtype of ovarian cancer. Notably, deleterious mutations in SWI/SNF chromatin remodeling genes, such as ARID1A, are common in OCCC but rare in HGSC. Because this complex regulates multiple cellular processes, including transcription and DNA repair, molecularly targeted therapies that exploit the consequences of SWI/SNF deficiency may have clinical efficacy against OCCC. Three such strategies have been proposed to date: prioritizing a gemcitabine-based chemotherapeutic regimen, synthetic lethal therapy targeting vulnerabilities conferred by SWI/SNF deficiency, and immune checkpoint blockade therapy that exploits the high mutational burden of ARID1A-deficient tumor. Thus, ARID1A deficiency has potential as a biomarker for precision medicine of ovarian cancer.

Clinical characteristics and prognosis of ovarian clear cell carcinoma: a 10-year retrospective study

Background

Ovarian clear cell carcinoma (OCCC) is a special pathological type of epithelial ovarian carcinoma (EOC). We conducted this research to investigate the clinical characteristics and outcomes of OCCC and to provide additional supporting evidence to aid in the clinical diagnosis and management.

Methods

This was a retrospective study investigating the clinical characteristics and survival outcomes of 86 patients with OCCC treated at our center between January 2010 and March 2020. Survival analysis was also performed on 179 patients with OCCC obtained from the Surveillance, Epidemiology and End Results (SEER) cancer registry database.

Results

The median age of participants was 49.21 ± 9.91 years old, and 74.42% of them were diagnosed at early stage. The median CA125 level was 601.48 IU/mL, while 19.77% of the patients had normal CA125 levels. Sixteen patients (18.60%) had co-existing endometriosis and 8 patients (9.3%) developed venous thromboembolism (VTE). There were 5 patients received suboptimal cytoreduction. Sixty-six patients (76.74%) underwent lymphadenectomy, and only 3 (4.55%) patients had positive lymph nodes. Patients diagnosed at an early stage had higher 3-year overall survival (OS) and progression-free survival (PFS) rates than those with advanced stage OCCC. CA19–9 (P = 0.025) and ascites (P = 0.001) were significantly associated with OS, while HE4 (P = 0.027) and ascites (P = 0.001) were significantly associated with PFS. Analysis of data from the SEER database showed that positive lymph nodes is also an independent prognostic factor for OS (P = 0.001).

Conclusions

OCCC often presents at an early stage and young age with a mildly elevated CA125. CA19–9, HE4, massive ascites, and positive lymph node are independent prognostic factors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08061-7.

Ovarian Cancer-Associated Mesothelial Cells: Transdifferentiation to Minions of Cancer and Orchestrate Developing Peritoneal Dissemination

Ovarian cancer has one of the poorest prognoses among carcinomas. Advanced ovarian cancer often develops ascites and peritoneal dissemination, which is one of the poor prognostic factors. From the perspective of the "seed and soil" hypothesis, the intra-abdominal environment is like the soil for the growth of ovarian cancer (OvCa) and mesothelial cells (MCs) line the top layer of this soil. In recent years, various functions of MCs have been reported, including supporting cancer in the OvCa microenvironment. We refer to OvCa-associated MCs (OCAMs) as MCs that are stimulated by OvCa and contribute to its progression. OCAMs promote OvCa cell adhesion to the peritoneum, invasion, and metastasis. Elucidation of these functions may lead to the identification of novel therapeutic targets that can delay OvCa progression, which is difficult to cure.

Residual Tumor Diameter Predicts Progression After Primary Debulking Surgery of Ovarian Clear Cell Carcinoma (OCCC): Clinicopathologic Study of Stage II-IV OCCC Patients from a Single Institution

Introduction

Ovarian clear cell carcinoma (OCCC) is a subtype of ovarian cancer characterized by highly aggressive and poor prognosis. However, it is unclear what factors are associated with OCCC recurrence and death. The study aimed to evaluate whether residual tumor diameter after primary debulking surgery, or other clinicopathological features play roles in predicting survival outcome in stage II–IV OCCC patients.

Material and Methods

We present a retrospective study of OCCC patients with stage II–IV in our department from 2010 to 2015. Kaplan–Meier method was used to draw a survival curve. Survival analysis was performed using Log-rank test for univariate analysis and COX proportional risk regression model for multivariate analysis.

Results

In this cohort of 78 patients who underwent primary debulking surgery, 47 patients had disease recurrence and 32 cases died. On univariate analysis, FIGO stage, residual tumor diameter and ascites were significant predictors of 3-year PFS (P values<0.05) and OS (P values<0.05). On multivariate analysis, the residual tumor diameter was an independent prognostic factor for 3-year PFS and OS (P values<0.05). The outcomes of patients in residual-free group were significantly better than those in the residual tumor diameter 0–1cm and >1cm group (PFS: P=0.000, OS: P=0.001), but there was no significant difference in prognosis between 0–1cm and > 1cm group (P values >0.05). Greater residual tumor diameter predicted progression on cox analysis in patients with stage III, but not for patients with stage IV.

Conclusion

Residual tumor diameter is prognostic after surgery for OCCC. Achieving no residual disease will significantly improve the prognosis in advanced OCCC patients.

Updates of Pathogenesis, Diagnostic and Therapeutic Perspectives for Ovarian Clear Cell Carcinoma

Ovarian clear cell carcinoma (OCCC) is a special pathological type of epithelial ovarian carcinoma (EOC) and has a high prevalence in Asia without specific molecular subtype classification. Endometriosis is a recognized precancerous lesion that carries 3-fold increased risk of OCCC. Ovarian endometrioid carcinoma, which also originates from endometriosis, shares several features with OCCC, including platinum resistance and younger age at diagnosis. Patients with OCCC have about a 2.5 to 4 times greater risk of having a venous thromboembolism (VTE) compared with other EOC, and OCCC tends to metastasize through lymphatic vesicular and peritoneal spread as opposed to hematogenous metastasis. There is only mild elevation of the conventional biomarker CA125. Staging surgery or optimal cytoreduction combined with chemotherapy is a common therapeutic strategy for OCCC. However, platinum resistance commonly portends a poor prognosis, so novel treatments are urgently needed. Targeted therapy and immunotherapy are currently being studied, including PARP, EZH2, and ATR inhibitors combined with the synthetic lethality of ARID1A-dificiency, and MAPK/PI3K/HER2, VEGF/bFGF/PDGF, HNF1β, and PD-1/PD-L1 inhibitors. Advanced stage, suboptimal cytoreduction, platinum resistance, lymph node metastasis, and VTE are major prognostic predictors for OCCC. We focus on update pathogenesis, diagnostic methods and therapeutic approaches to provide future directions for clinical diagnosis and treatment of OCCC.

International trends in ovarian cancer incidence from 1973 to 2012

PURPOSE

Ovarian cancer is the 7th leading cancer diagnosis and the 8th leading cause of cancer death in women worldwide. We conducted this study to investigate the incidence of ovarian cancer internationally.

METHODS

The trends in ovarian cancer incidence were analyzed through the latest data of CI5 over the 40-year period from 21 populations in 4 continents using Joinpoint analysis, ASRs and proportions of different histological subtypes in those populations were also analyzed using volume XI of CI5.

RESULTS

ASRs of ovarian cancer were from 7.0 to 11.6 per 100,000 in non-Asia populations during 2008-2012. In Asia, the ASR in Israel (Jews) were the highest, up to 8.1 per 100,000 in the same period. The international trends from 1973 to 2012 showed that ASRs of ovarian cancer were decreasing in 8 of 21 selected populations, whereas ASRs in Slovakia, Spain (Navarra) and China (Shanghai) were increasing. Meanwhile, there are certain differences in the main pathological classification patterns within different regions. In Asia, China (Hong Kong) and Japan both have a higher ASRs and proportions for clear cell and endometrioid carcinomas, while Japan has the highest ASRs and proportions for mucinous carcinomas.

CONCLUSION

Although the reasons for those trends were not entirely clear, environmental, reproductive and genetic factors were likely to have led to these patterns. Meanwhile, more attention and further study should be given to the etiological factors of histology-specific ovarian cancer.

Clinical characteristics and prognostic factors of stage IC ovarian clear cell carcinoma: a Surveillance, Epidemiology, and End Results (SEER) analysis

PURPOSE

The study aimed to investigate the clinical characteristics and prognostic factors of stage IC ovarian clear cell carcinoma (OCCC).

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was accessed for medical records of patients with stage IC OCCC from 1992 to 2016. The clinical and prognostic features of stage IC OCCC from several therapeutic perspectives were identified with Kaplan-Meier method and Cox proportional hazards model.

RESULTS

Totally, 1079 patients were enrolled for the analysis. The median age was 55 (range 24-91) years. 850 (78.8%) patients were treated with chemotherapy, 877 (81.3%) received lymph node (LN) dissection, and 20 (1.9%) underwent radiotherapy. LN dissection (P = 0.501) and chemotherapy (P = 0.130) did not significantly impact cancer-specific survival (CSS). Among patients younger than 45 years, 23 received fertility-sparing surgery (FSS). No significant difference in CSS was observed between the FSS and non-FSS group (P = 0.523). Bilateral tumor (P < 0.001) and larger tumor size (P = 0.010) were significantly and independently associated with poor CSS. Older age (P = 0.001), bilateral tumor (P < 0.001), and larger tumor size (P = 0.005) were significantly and independently associated with poor overall survival (OS), while LN dissection (P = 0.005) was significantly and independently associated with better OS. Significant differences in CSS (P = 0.005) and OS (P < 0.001) were observed between the low- and high-risk groups, which were divided by median risk score.

CONCLUSION

LN dissection and chemotherapy did not significantly impact CSS, while LN dissection was an independent prognostic factor for OS. Convincing evidence from clinical trials with a large number of patients are further required to develop treatment guidelines.

Tissue factor pathway inhibitor‑2 is specifically expressed in ovarian clear cell carcinoma tissues in the nucleus, cytoplasm and extracellular matrix

Tissue factor pathway inhibitor-2 (TFPI-2) is a promising candidate as a serum biomarker of ovarian clear cell carcinoma (OCCC), a lethal histological subtype of epithelial ovarian cancer (EOC). TFPI-2 is a secreted serine protease inhibitor that suppresses cancer progression through the inhibition of matrix protease activities. Previous studies have also identified TFPI-2 in the nucleus, and a possible function of nuclear TFPI-2 as a transcriptional repressor of matrix metalloproteinase-2 (MMP-2) was recently demonstrated. We are currently establishing TFPI-2 as a serum biomarker for OCCC patients; however, TFPI-2 expression in OCCC tissues has not been previously investigated. In the present study, we examined TFPI-2 expression and its localization in 11 OCCC cell lines by western blotting and enzyme-linked immune assay. Four cell lines expressed TFPI-2 in the nucleus, cytoplasm and culture plate–attached extracellular fraction, while four other cell lines expressed TFPI-2 only in the extracellular fraction. In the remaining three cell lines, TFPI-2 was not identified in any fraction. The amount of secreted soluble TFPI-2 showed similar trends to that of the plate-attached fraction. We next investigated the expression levels and distribution of TFPI-2 in surgically resected EOC tissues by immunohistochemistry. In 52 of the 77 (67.5%) OCCC tumors, TFPI-2 expression was detected in at least one of the nuclear, cytoplasmic and extracellular matrix fractions. In contrast, we did not identify TFPI-2 in the other EOC subtypes (n=65). TFPI-2-positive expression distinguished CCC from the other EOC tissues with a sensitivity of 67.5% and specificity of 100%. Although the inherent tumor suppressor function, statistical analyses failed to demonstrate correlations between TFPI-2 expression and clinical parameters, including 5-year overall survival, except for the patient age. In conclusion, we identified TFPI-2 expression in the nucleus, cytoplasm and extracellular matrix in OCCC tissues. The high specificity of TFPI-2 may support its use for diagnosis of OCCC in combination with existing markers.

The prevalence, risk factors, and prognostic value of venous thromboembolism in ovarian cancer patients receiving chemotherapy: a systematic review and meta-analysis

BACKGROUND

Venous thromboembolism (VTE) in ovarian cancer (OC) patients has been widely investigated, but our knowledge on the role of VTE in OC patients receiving chemotherapy is limited. The aim of our study was to investigate the prevalence, risk factors, and prognostic value of chemotherapy-associated VTE in OC.

METHODS

Three databases (PubMed, Embase, and the Cochrane Library) were systematically searched from inception to October 14, 2020. The primary outcome was the prevalence of VTE in OC patients receiving chemotherapy. The risk factors and prognostic value of VTE were the secondary outcomes. The pooled prevalence of VTE was estimated using the generic inverse-variance method. The statistical heterogeneity was evaluated with Cochran's Q test and I² statistic. Funnel plot, Begg's test, and Egger's test were used to assess the potential publication bias in the meta-analysis.

RESULTS

A total of eleven observational studies with 4759 OC patients were included. The pooled prevalence of VTE was 9% (95% CI, 0.06-0.12) in OC patients receiving chemotherapy. The results of subgroup analysis and sensitivity analysis were basically consistent with the overall pooled estimate. Multiple significant risk factors associated with VTE were also identified including advanced age, D-dimer > 0.5 mg/mL, and tumor diameter > 10 cm. Only two included studies reported the prognostic value of VTE in OC patients receiving chemotherapy, but with inconsistent results. Funnel plot showed that there existed potential publication bias, which was further verified by statistical test, but the results of the trim-and-fill method showed the pooled estimate kept stable after adding two "missing" studies.

CONCLUSIONS

This current study revealed that the pooled prevalence of chemotherapy-related VTE in OC was approximately 9% in OC patients. Risk factors for chemotherapy-related VTE were also identified which may contribute to targeting potentially preventative measures for VTE in OC.

Tetraspanin 1 promotes endometriosis leading to ovarian clear cell carcinoma

Ovarian clear cell carcinoma (OCCC) reportedly develops from endometriosis. However, the molecular mechanism underlying its malignant progression to OCCC remains elusive. This study aimed to identify an essential gene in the malignant transformation of endometriosis to OCCC. We performed RNA sequencing in formalin‐fixed, paraffin‐embedded (FFPE) tissues of endometriosis (n = 9), atypical endometriosis (AtyEm) (n = 18), adjacent endometriosis to OCCC (AdjEm) (n = 7), and OCCC (n = 17). We found that tetraspanin 1 (TSPAN1) mRNA level was significantly increased by 2.4‐ (DESeq2) and 3.4‐fold (edgeR) in AtyEm and by 80.7‐ (DESeq2) and 101‐fold (edgeR) in OCCC relative to endometriosis. We confirmed that TSPAN1 protein level was similarly overexpressed in OCCC tissues and cell lines. In immortalized endometriosis cell lines, TSPAN1 overexpression enhanced cell growth and invasion. Mechanistically, TSPAN1 triggered AMP‐activated protein kinase (AMPK) activity, promoting endometriosis and cell growth. Upregulated levels of TSPAN1 are considered an early event in the development of high‐risk endometriosis that could progress to ovarian cancer. Our study suggests the potential of TSPAN1 as a screening candidate for high‐risk endometriosis.

Is There a Survival Benefit for Patients with Advanced Ovarian Clear Cell Carcinoma Who Complete More Than 6 Cycles of Postoperative Chemotherapy?

Purpose

To provide a reference for clinicians, whether patients with advanced ovarian clear cell carcinoma (OCCC) require chemotherapy (CT) for more than 6 cycles after tumor debulking.

Patients and Methods

A retrospective review was performed on 85 women diagnosed and treated for advanced OCCC. Outcomes of patients who underwent >6 vs ≤6 cycles of CT were analyzed based on clinicopathological factors.

Results

Among the 85 patients with advanced OCCC, 47 patients underwent ≤6 cycles of CT, and 38 patients underwent CT for over 6 cycles. Out of these, 49 patients had disease recurrence, and 35 died. The 2-year progression-free survival (PFS) for patients in the two groups was 51.5% and 42.2% (P＞0.05), respectively. The 2-year overall survival (OS) was 59.7% and 64.5%, respectively (P＞0.05), and the difference was not statistically significant. Multivariate analysis showed that residual tumor diameter was an independent risk factor for prognosis (PFS and OS). We divided the patients into three groups according to residual tumor diameter as 0 (R0), ≤1cm (R1), and >1cm (R2). The prognosis of R0 was better than R1 and R2. Further studies found that patients who received postoperative adjuvant chemotherapy for over 6 cycles showed no difference in improved prognosis, regardless of residual tumor diameter.

Conclusion

Patients with advanced OCCC who received more than 6 courses of adjuvant chemotherapy after surgery did not show improved prognosis. The residual tumor diameter is an independent indicator of prognosis in patients with advanced OCCC. Complete staging improves the prognosis of patients compared to the ideal or non-ideal cytoreductive surgery.

Prevalence of pathogenic variants in actionable genes in advanced ovarian cancer: a next-generation sequencing analysis of a nationwide registry study

BACKGROUND

We examined the actionable genomic alterations in ovarian cancer by analysing the nationwide registry of next-generation sequencing (NGS) data.

METHODS

From March 2017 to December 2018, 16,458 patients with cancer underwent NGS testing under the interim coverage programme for NGS provided by the National Health Insurance of Korea. Among these patients, 779 patients had advanced ovarian cancer. Fifty-eight mutations were reported as pathogenic variants, which included likely pathogenic variants, and 55 theoretically actionable genes were analysed.

RESULTS

The prevalence of pathogenic mutations in the population was 81.5%, whereas 11.6% of the population had neither a pathogenic mutation nor a variant of unknown significance. Common pathogenic mutations shared by at least 3% of the study population were mutations in TP53 (61.5%), BRCA1 (12.2%), PIK3CA (10.4%), KRAS (10.3%), BRCA2 (9.6%) and PTEN (3.7%). BRCA1/2 pathogenic mutations were found in 14.0% (42 of 300, 95% confidence interval = 10-18%) of the patients with TP53 wild-type tumours, comprising approximately one-quarter (25.9%) of the total observed BRCA1/2 pathogen mutations. At least one pathogenic mutation in a theoretically actionable gene was found in 49.2% of patients. Among patients without a BRCA1/2 pathogenic mutation, mutations were frequently observed in KRAS (12.2%), PIK3CA (10.4%) and PTEN (4.2%). PTCH1 mutations were correlated with ATM, NF1, ERBB2 and MTOR mutations (adjusted p = 0.0054, p = 0.0035, p = 0.0010 and p = 0.0003, respectively).

CONCLUSIONS

Almost half of patients with ovarian cancer could be estimated as theoretical candidates for genomic medicine. Substantial BRCA1/2 pathogenic mutations were observed in patients not harbouring a TP53 mutation.

Development and validation of Nomograms for predicting overall survival and Cancer-specific survival in patients with ovarian clear cell carcinoma

BACKGROUND

Ovarian clear cell carcinoma (OCCC) is a rare histologic type of ovarian cancer. There is a lack of an efficient prognostic predictive tool for OCCC in clinical work. This study aimed to construct and validate nomograms for predicting the overall survival (OS) and cancer-specific survival (CSS) in patients with OCCC.

METHODS

Data of patients with primary diagnosed OCCC in the Surveillance, Epidemiology, and End Results (SEER) database between 2010 and 2016 was extracted. Prognostic factors were evaluated with LASSO Cox regression and multivariate Cox regression analysis, which were applied to construct nomograms. The performance of the nomogram models was assessed by the concordance index (C-index), calibration plots, decision curve analysis (DCA) and risk subgroup classification. The Kaplan-Meier curves were plotted to compare survival outcomes between subgroups.

RESULTS

A total of 1541 patients from SEER registries were randomly divided into a training cohort (n = 1079) and a validation cohort (n = 462). Age, laterality, stage, lymph node (LN) dissected, organ metastasis and chemotherapy were independently and significantly associated with OS, while laterality, stage, LN dissected, organ metastasis and chemotherapy were independent risk factors for CSS. Nomograms were developed for the prediction of 3- and 5-year OS and CSS. The C-indexes for OS and CSS were 0.802[95% confidence interval (CI) 0.773-0.831] and 0.802 (0.769-0.835), respectively, in the training cohort, while 0.746 (0.691-0.801) and 0.770 (0.721-0.819), respectively, in the validation cohort. Calibration plots illustrated favorable consistency between the nomogram predicted and actual survival. C-index and DCA curves also indicated better performance of nomogram than the AJCC staging system. Significant differences were observed in the survival curves of different risk subgroups.

CONCLUSIONS

We have constructed predictive nomograms and a risk classification system to evaluate the OS and CSS of OCCC patients. They were validated to be of satisfactory predictive value, and could aid in future clinical practice.

Proposal of a Two-Tier System in Grouping Adenocarcinoma of the Uterine Cervix

(1) Background: This study examined the use of a two-tier system in grouping cervical adenocarcinoma for survival discrimination. (2) Methods: A nationwide retrospective observational cohort study was conducted using the Japan Society of Gynecologic Oncology tumor registry database from 2001 to 2015 (n = 86,754). Adenocarcinoma subtypes were grouped as type 1 (endocervical usual type and endometrioid) or type 2 (serous, clear, mucinous, and not otherwise specified), based on their relative survival compared with that of squamous tumors. (3) Results: The majority of the adenocarcinoma cases were type 1 (n = 10,121) versus type 2 tumors (n = 5157). Type 2 tumors were more likely to be old and have stage IV disease than those with squamous tumors. The number of type 2 tumors increased from 2001 to 2014 (106.1% relative increase, p < 0.001). Type 2 tumors had disproportionally poorer survival compared to other types (5-year survival rates: 68.9% for type 2, 75.4% for type 1, and 78.0% for squamous; p < 0.001). On multivariate analysis, type 2 tumors remained an independent prognostic factor associated with decreased survival compared with squamous (adjusted hazard ratio 2.00, 95% CI 1.84–2.15, p < 0.001). (4) Conclusion: The survival of cervical adenocarcinoma varies largely across the histological subtypes, and the proposed two-tier grouping may be useful for survival discrimination.

Intraoperative Capsule Rupture, Postoperative Chemotherapy, and Survival of Women With Stage I Epithelial Ovarian Cancer

The incidence and prognostic significance of intraoperative capsule rupture in apparent stage IA-B ovarian cancer varies across histologies, and postoperative chemotherapy was not associated with improved survival.

To examine the incidence and prognostic effects of intraoperative capsule rupture and to assess the effectiveness of postoperative chemotherapy for intraoperative tumor rupture in apparent stage I epithelial ovarian cancer.

Pembrolizumab monotherapy in Japanese patients with advanced ovarian cancer: Subgroup analysis from the KEYNOTE-100

Interim results from the two-cohort, phase 2 KEYNOTE-100 study (NCT02674061) of 376 patients with previously treated advanced recurrent ovarian cancer (ROC) showed that pembrolizumab monotherapy was associated with an objective response rate (ORR) of 8.0% (95% CI, 5.4-11.2). We present outcomes for the Japanese patients (n = 21) enrolled in KEYNOTE-100. Patients with epithelial ROC had received either 1-3 prior chemotherapy lines and had platinum-free interval or treatment-free interval (PFI; TFI) of 3-12 months (cohort A) or 4-6 prior chemotherapy lines and had PFI/TFI of ≥3 months (cohort B). All patients received pembrolizumab 200 mg every 3 weeks as monotherapy for 2 years or until progression, death, unacceptable toxicity or consent withdrawal. Primary objectives were ORR per RECIST v1.1 for each cohort and higher programmed death ligand-1 (PD-L1) tumor expression. The relationship between PD-L1 expression (measured as combined positive score [CPS]) and ORR was assessed. Twenty-one Japanese patients (cohort A, n = 19; cohort B, n = 2) were treated. The median (range) age was 57 (37-78) years; 19 (90.5%) patients had ECOG status of 0 and 16 (76.2%) patients had stage III-IV disease. ORR was 19.0% (95% CI, 5.4-41.9) and seemed to increase with increasing PD-L1 expression. A total of 13 (61.9%) patients had treatment-related adverse events (TRAE), and 5 (23.8%) had grade 3-4 TRAE. There were no treatment-related deaths in this subpopulation. Pembrolizumab monotherapy was associated with antitumor activity in Japanese patients with ROC, with no new safety signals identified in this subpopulation. The data suggested a trend toward higher PD-L1 expression among some patients with higher ORR.

High glypican-3 expression characterizes a distinct subset of ovarian clear cell carcinomas in Canadian patients: an opportunity for targeted therapy

The expression frequency and distribution of glypican-3 (GPC3) was retrospectively assessed by immunohistochemistry in 316 accurately phenotyped ovarian clear cell carcinoma (OCCC) specimens from Canadian patients. The study aimed to evaluate the prevalence of this biomarker in OCCC in a mixed-ethnicity Canadian population and to evaluate associations of GPC3 expression with clinicopathological parameters. Tissue microarrays with napsin A or HNF1β positive and WT1-negative OCCC specimens were evaluated using a GPC3 antibody clone 1G12. Membranous, cytoplasmic, and Golgi pattern GPC3 expression was noted in 184 of 316 (58.2%) cases; 63 of 316 (20%) cases showed high GPC3 expression (>50% of tumor cells were positive). GPC3 expression was not associated with age, stage, and residual disease after primary surgery. High GPC3 expression did not correlate with a specific morphological pattern or the presence of endometriosis. Furthermore, GPC3 expression was not significantly associated with survival in the entire cohort. Statistically significant association of high GPC3 expression was noted with higher body mass index, napsin A positivity, estrogen receptor (ER) negativity, and ARID1A retention. In a stratified analysis by ARID1A status, high GPC3 expression was significantly associated with unfavorable outcomes in cases with loss of ARID1A (n=10; log rank p=0.0048). Women diagnosed with OCCC and high GPC3 expression were also more likely to receive adjuvant chemotherapy. Considering the tumor-specific membranous expression of GPC3 in 58% of cases and high interobserver reproducibility, GPC3 immunohistochemistry is a robust predictive test for inclusion in clinical trials for GPC3-targeted therapies for OCCC.

Rethinking of treatment strategies and clinical management in ovarian clear cell carcinoma

Ovarian clear cell carcinoma (OCCC), with unique clinical and molecular characteristics compared with other histological types of epithelial ovarian cancer (EOC), behaves like a distinct entity and has a poorer prognosis than other EOC types, especially in advanced stages. In addition, OCCC comprises approximately 27% of all EOC cases in Japan, compared with 12% in Western countries. Historically, patients with OCCC have been eligible for chemotherapeutic and surgical trials of EOC. It has been difficult to evaluate the specific impact of these trials on the prognosis of women with OCCC because of its rarity and unique molecular characteristics. Recent studies of OCCC revealed significant molecular variations related to carcinogenesis and molecular targets that could directly facilitate patient stratification and subsequent precision medicine. Thus, treatment strategies specific for OCCC based on its clinical and molecular characteristics are urgently needed. In this review, we highlight the management and treatment of OCCC from clinical aspects.

Evolving population-based statistics for rare epithelial ovarian cancers

OBJECTIVE

To describe how population-based statistics for rare epithelial ovarian cancers are evolving.

METHODS

This is a retrospective observational study examining the Surveillance, Epidemiology, and End Results Program from 1988 to 2016. Overall survival (OS) of clear cell (OCCC), mucinous (MOC), and low-grade serous (LGSOC) ovarian cancers were compared to high-grade serous ovarian cancer (HGSOC) by fitting a propensity score matching.

RESULTS

Among 113,365 ovarian malignancies, 5780 OCCCs (5.1%), 7561 MOCs (6.7%), and 2021 LGSOCs (1.8%) were compared to 38,199 HGSOCs. OCCCs and MOCs were more likely to be diagnosed with stage I disease compared to HGSOC (57.0-59.5% versus 8.6%, P<0.001). For early-stage disease, OCCC (hazard ratio [HR] 0.91, 95% confidence interval [CI] 0.82-1.01) and MOC (HR 0.94, 95%CI 0.85-1.04) had similar OS to HGSOC whereas LGSOC had superior OS (HR 0.93, 95%CI 0.89-0.97) versus HGSOC. Conversely, for advanced-stage disease, OCCC (HR 1.42, 95%CI 1.32-1.53) and MOC (HR 1.11, 95%CI 1.09-1.13) had poorer OS whereas LGSOC (HR 0.86, 95%CI 0.84-0.89) had superior OS compared to HGSOC. OCCC (HR range, 1.92-2.45) and MOC (HR range, 1.73-2.22) had particularly poorer OS in the first three years following diagnosis compared to HGSOC. Population-level statistics for advanced-stage disease showed that 5-year OS rates have increased in HGSOC (16.9% to 36.8%, P<0.001) and LGSOC (50.8% to 66.4%, P=0.010); but remain unchanged for OCCC (21.0% to 28.2%, P=0.174) and MOC (21.4% to 16.5%, P=0.102).

CONCLUSION

OCCC, MOC, and LGSOC comprise 2-7% of ovarian malignancies, have distinct characteristics and survival compared to HGSOC. While these rare tumors have a favorable to comparable prognosis in early-stage disease, disproportionally poor survival in advanced-stage OCCC and MOC highlights the need for further research into novel treatment strategies.

Analysis of gene expression signatures identifies prognostic and functionally distinct ovarian clear cell carcinoma subtypes

Background

Ovarian clear cell carcinoma (OCCC) is a histological subtype of epithelial ovarian cancer (EOC) with distinct pathological, biological, and molecular features. OCCCs are more resistant to conventional treatment regimen of EOC and have the worst stage-adjusted prognosis amongst EOC subtypes. As the OCCC incidence rate in Asian populations has significantly increased in recent decades, it is critical to elucidate its molecular features that could lead to OCCC-tailored therapeutic strategies.

Methods

Gene expression profiles of 222 OCCC were analyzed by hierarchical clustering and statistical analyses.

Findings

We identified two OCCC gene expression subtypes: EpiCC—epithelial-like, which is associated with early-stage disease, with a relatively higher rate of gene mutations in the SWI/SNF complex; and MesCC—mesenchymal-like, associated with late-stage and higher enrichment of immune-related pathway activity. Genetic, copy number and transcriptomic analyses showed that both EpiCC and MesCC carried OCCC-associated aberrations. The EpiCC/MesCC classification was reproducible in validation cohorts and OCCC cell lines. MesCC tumors had a poorer progression-free survival (PFS) than EpiCC tumors (HR: 3·0, p = 0·0006). Functional assays in cell lines showed that the MesCC subtype was more proliferative and more anoikis-resistant than the EpiCC. By applying the EpiCC/MesCC classification to the TCGA renal clear cell carcinoma cohort, our results indicated interoperability of the subtyping scheme, and revealed preferential drug response of MesCC to bevacizumab.

Interpretation

The EpiCC/MesCC classification shows promise for prognostic and therapeutic stratification in OCCC patients and warrants further investigation in the context of OCCC gene expression subtype-tailored treatment strategies.

Clinical Characteristics of Clear Cell Ovarian Cancer: A Retrospective Multicenter Experience of 308 Patients in South Korea

Purpose

The purpose of this study was to evaluate clinical characteristics and treatment pattern of ovarian clear cell carcinoma (OCCC) in Korea and the role of adjuvant chemotherapy in early-stage.

Materials and Methods

Medical records of 308 cases of from 21 institutions were reviewed and data including age, performance status, endometriosis, thromboembolism, stage, cancer antigen 125, treatment, recurrence, and death were collected.

Results

Regarding stage of OCCC, it was stage I in 194 (63.6%), stage II in 34 (11.1%), stage III in 66 (21.6%), and stage IV in 11 (3.6%) patients. All patients underwent surgery. Optimal surgery (residual disease ≤ 1 cm) was achieved in 89.3%. Majority of patients (80.5%) received postoperative chemotherapy. The most common regimen was taxane-platinum combination (96%). Median relapse-free survival (RFS) was 138.5 months for stage I, 33.4 for stage II, 19.3 for stage III, and 9.7 for stage IV. Median overall survival (OS) were not reached, 112.4, 48.7, and 18.3 months for stage I, II, III, and IV, respectively. Early-stage (stage I), endometriosis, and optimal debulking were identified as favorable prognostic factors for RFS. Early-stage and optimal debulking were also favorable prognostic factors for OS. Majority of patients with early-stage received adjuvant chemotherapy. However, additional survival benefit was not found in terms of recurrence.

Conclusion

Majority of patients had early-stage and received postoperative chemotherapy regardless of stage. Early-stage and optimal debulking were identified as favorable prognostic factors. In stage IA or IB, adding adjuvant chemotherapy did not show difference in survival. Further study focusing on OCCC is required.

Comprehensive Serum Glycopeptide Spectra Analysis (CSGSA): A Potential New Tool for Early Detection of Ovarian Cancer

Objectives: To conduct a comprehensive glycopeptide spectra analysis of serum between cancer and non-cancer patients to identify early biomarkers of epithelial ovarian cancer (EOC). Methods: Approximately 30,000 glycopeptide peaks were detected from the digested serum glycoproteins of 39 EOC patients (23 early-stage, 16 advanced-stage) and 45 non-cancer patients (27 leiomyoma and ovarian cyst cases, 18 endometrioma cases) by liquid chromatography mass spectrometry (LC–MS). The differential glycopeptide peak spectra were analyzed to distinguish between cancer and non-cancer groups by employing multivariate analysis including principal component analysis (PCA), orthogonal partial least squares discriminant analysis (OPLS-DA) and heat maps. Results: Examined spectral peaks were filtered down to 2281 serum quantitative glycopeptide signatures for differentiation between ovarian cancer and controls using multivariate analysis. The OPLS-DA model using cross-validation parameters R2 and Q2 and score plots of the serum samples significantly differentiated the EOC group from the non-cancer control group. In addition, women with early-stage clear cell carcinoma and endometriomas were clearly distinguished from each other by OPLS-DA as well as by PCA and heat maps. Conclusions: Our study demonstrates the potential of comprehensive serum glycoprotein analysis as a useful tool for ovarian cancer detection.