Update on rare epithelial ovarian cancers: based on the Rare Ovarian Tumors Young Investigator Conference

Molecular classification of ovarian high-grade serous/endometrioid carcinomas through multi-omics analysis: JGOG3025-TR2 study

BACKGROUND

Considerable interobserver variability exists in diagnosis of ovarian high-grade endometrioid carcinoma (HGEC) and high-grade serous carcinoma (HGSC) due to histopathological similarities. While homologous recombination deficiency (HRD) correlates with drug sensitivity in HGSC, the molecular features of HGEC are unclear.

METHODS

Fresh-frozen samples from 15 ovarian HGECs and 274 ovarian HGSCs in the JGOG-TR2 cohort were submitted to targeted DNA sequencing, RNA sequencing, DNA methylation array, and SNP array. We additionally analyzed 555 ovarian HGSCs from TCGA-OV and 287 endometrial high-grade carcinomas from TCGA-UCEC.

RESULTS

Unsupervised clustering using copy number signatures identified four distinct tumor groups (C1, C2, C3 and C4). C1 (n = 41) showed CCNE1 amplification and poor survival. C2 (n = 160) and C3 (n = 59) showed high BRCA1/2 alteration frequency with low and moderate ploidy, respectively. C4 (n = 22) was characterized by favorable outcome, higher HGEC proportion, no BRCA1/2 alteration or CCNE1 amplification, and low levels of HRD score, ploidy, intra-tumoral heterogeneity, cell proliferation rate, and WT1 gene expression. Notably, C4 exhibited a normal endometrium-like DNA methylation profile, thus, defined as "HGEC-type" tumors, which were also identified in TCGA-OV and TCGA-UCEC.

CONCLUSIONS

Ovarian "HGEC-type" tumors present a non-HRD status, favorable prognosis, and endometrial differentiation, possibly constituting a subset of clinically diagnosed HGSCs.

From clinical management to personalized medicine: novel therapeutic approaches for ovarian clear cell cancer

Ovarian clear-cell cancer is a rare subtype of epithelial ovarian cancer with unique clinical and biological features. Despite optimal cytoreductive surgery and platinum-based chemotherapy being the standard of care, most patients experience drug resistance and a poor prognosis. Therefore, novel therapeutic approaches have been developed, including immune checkpoint blockade, angiogenesis-targeted therapy, ARID1A synthetic lethal interactions, targeting hepatocyte nuclear factor 1β, and ferroptosis. Refining predictive biomarkers can lead to more personalized medicine, identifying patients who would benefit from chemotherapy, targeted therapy, or immunotherapy. Collaboration between academic research groups is crucial for developing prognostic outcomes and conducting clinical trials to advance treatment for ovarian clear-cell cancer. Immediate progress is essential, and research efforts should prioritize the development of more effective therapeutic strategies to benefit all patients.

Endometriosis and epithelial ovarian cancer: a two-sample Mendelian randomization analysis

Endometriosis, a prevalent condition, has long been recognized as a chronic and debilitating ailment affecting an estimated 1790 million women worldwide. Observational studies have established a correlation between endometriosis and ovarian cancer. Thus, we endeavored to employ Two-Sample Mendelian Randomization, utilizing summary statistics from a Genome-Wide Association Study of endometriosis and epithelial ovarian cancer, with genetic markers serving as proxies for epithelial ovarian cancer. The analysis revealed a significant correlation between these entities, with an odds ratio (OR) of 1.23 (95% CI 1.11-1.36). Upon histotype-specific examination, robust evidence emerged for an association of endometriosis with the risk of endometrioid carcinoma (OR 1.49, 95% CI 1.24-1.81), clear cell carcinoma (OR 2.56, 95% CI 1.75-3.73), and low malignant potential tumors (OR 1.28, 95% CI 1.08-1.53). These findings provide a theoretical framework for prospective investigations aimed at enhancing the potential therapeutic efficacy of managing endometriosis in averting the onset and progression of ovarian cancer.

Clinical perspectives of rare ovarian tumors: clear cell ovarian cancer

Ovarian clear cell carcinoma (OCCC) is a rare and distinct histological type of epithelial ovarian carcinoma in terms of its histopathological, clinical and genetic features. Patients with OCCC are younger and diagnosed at earlier stages than those with the most common histological type-high-grade serous carcinoma. Endometriosis is considered a direct precursor of OCCC. Based on preclinical data, the most frequent gene alternations in OCCC are mutations of AT-rich interaction domain 1A and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha. The prognosis of patients with early-stage OCCC is favorable, whereas patients at an advanced stage or who have the recurrent disease have a dismal prognosis due to OCCC's resistance to standard platinum-based chemotherapy. Despite a lower rate of response due to its resistance to standard platinum-based chemotherapy, the treatment strategy for OCCC resembles that of high-grade serous carcinoma, which includes aggressive cytoreductive surgery and adjuvant platinum-based chemotherapy. Alternative treatment strategies, including biological agents based on molecular characteristics specific to OCCC, are urgently needed. Furthermore, due to its rarity, well-designed collaborative international clinical trials are needed to improve oncologic outcomes and the quality of life in patients with OCCC.

Oncological and Reproductive Outcomes After Fertility-Sparing Surgery for Stage I Mucinous Ovarian Carcinoma

Background

Fertility-sparing surgery (FSS) has been widely used for patients with early-stage mucinous ovarian carcinoma (MOC). However, there is limited evidence regarding the reproductive outcomes as well as the impact of growth pattern on oncological outcomes after FSS. This study aims to evaluate the oncological and reproductive outcomes of patients with stage I primary MOC after FSS.

Methods

This retrospective study enrolled 159 women with histologically confirmed unilateral stage I MOC treated at Peking Union Medical College Hospital between 1997 and 2019. Sixty-seven cases were pathologically reviewed for the growth pattern. Seventy-eight patients had FSS, defined as conservation of the uterus and at least part of one ovary, while 81 underwent radical surgery (RS). Oncofertility outcomes were compared between the groups and clinicopathological factors associated with disease-free survival (DFS) were analyzed by univariate and multivariate analyses. Patients in the FSS group were contacted to collect data on reproductive outcomes.

Results

Eighteen patients developed recurrent disease during a median follow-up of 69 months, including 12 in the FSS and six in the RS group. There was one death each in the FSS and RS groups. There was no significant difference in DFS between the groups. CA125 >35 U/ml, stage IC, and incomplete staging were correlated with worse DFS according to multivariate analysis (P=0.001; 0.020 (stage IC) and 0.004 (incomplete staging) respectively). There was no significant difference in DFS between patients with stage IA and stage IC1 in the FSS group, while DFS was poorer in patients with stage IC2/3 than stage IA (P=0.028). In addition, DFS was significantly poorer in patients who underwent unilateral salpingo-oophorectomy (USO) compared with those receiving USO plus staging surgery (P=0.015). There was a tendency towards poorer DFS in the infiltrative tumors compared with the expansile tumors (P=0.056). Of 23 patients who attempted to conceive, 21 (91.3%) achieved 27 pregnancies, including 26 spontaneous pregnancies and one following assisted reproductive technology. Twenty patients gave birth to 24 healthy babies, including 21 full-term and three premature births. The live-birth rate was 88.9%.

Conclusions

FSS is a suitable option for young women with unilateral stage I expansile MOC, with acceptable oncological outcomes and meaningful pregnancy rates. Re-staging should be proposed in patients who undergo incomplete staging surgery.

Remarkable Response to the Triplet Combination of Olaparib with Pembrolizumab and Bevacizumab in the Third-Line Treatment of an Ovarian Clear Cell Carcinoma Patient with an ARID1A Mutation: A Case Report

Ovarian clear cell carcinoma (OCCC) is a highly aggressive malignancy with a poor prognosis, and most patients experience recurrence after primary treatment. Currently, there is no standard treatment option for recurrent OCCC. Herein, we report the case of a 32-year-old female patient with OCCC. The patient received primary cytoreductive surgery with adjuvant chemotherapy and remained disease-free for four months. She then experienced retroperitoneal lymph node recurrence and was treated with liposomal doxorubicin chemotherapy followed by secondary debulking surgery. The patient experienced a second relapse in the lower left lung 11 months later. Genomic profiling of tumor samples revealed a deleterious AT-rich interactive domain 1A (ARID1A) mutation and homologous recombination deficiency. Thus, the triplet combination of the poly (ADP-ribose) polymerase (PARP) inhibitor, olaparib; the PD-1 inhibitor, pembrolizumab; and the antiangiogenic agent, bevacizumab was administered. The patient achieved partial response, which was sustained for 12 months. Our study provides the first clinical evidence that the combination of olaparib with pembrolizumab and bevacizumab could be an effective treatment for patients with platinum-resistant, recurrent OCCC.

Clear cell carcinoma of the ovary: Epidemiology, pathological and biological features, treatment options and clinical outcomes

Clear cell carcinoma of the ovary is a rare and distinct histotype of epithelial ovarian carcinomas. Women diagnosed with clear cell carcinomas are usually younger and diagnosed at earlier stages than those with the most common high-grade serous histology. Endometriosis is considered a main risk factor for the development of clear cell carcinoma of the ovary, and it can be considered a precursor of of this tumor, as it is identified in more than 50% of patients with clear cell carcinoma. Different molecular pathways and alterations heve been identified in ovarian clear cell carcinoma, including the most common mutations of AT-rich interaction domain 1A [ARID1A] and phosphatidylinositol-4,5-bisphosphate 3-kinase [PIK3] catalytic subunit alpha [PIK3CA]. The prognosis of patients at early stage is favorable, while patients with advanced or recurrent disease experience a poor oncologic outcomes. Despite a lower rate of responses due to an intrinsic chemoresistance, the treatment strategy for advanced disease resembles the treatment of high-grade serous carcinoma, which includes aggressive cytoreductive surgery and platinum-based chemotherapy. For this reason, the role of adjuvant chemotherapy in patients with stage I disease undergoing complete surgical staging is still under debate. Alternative treatments, including biological agents that target different pathways constitute the most promising treatment strategies, and well-designed, collaborative international trials should be designed in order to improve the oncologic outcomes and the quality of life of patients with this aggressive disease.

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.

Precision medicine for ovarian clear cell carcinoma based on gene alterations

Ovarian clear cell carcinoma (OCCC) is a histological subtype of epithelial ovarian carcinoma prevalent in Asians. No clear therapeutic selection based on molecular profile has been implemented for this disease. Oncogenic PIK3CA mutation, which activates the PIK3CA/AKT/mTOR signaling pathway, is a promising druggable alteration in OCCC. Recent studies by our group and others have identified the ARID1A mutation as another alteration linked to therapeutic selection based on synthetic lethality: deleterious ARID1A mutations, resulting in ARID1A deficiency, make OCCC cells sensitive to drugs targeting poly (ADP-ribose) polymerase and EZH2, as well as to glutathione inhibitors. In addition, we recently obtained evidence that ARID1A-deficient OCCC could benefit from gemcitabine treatment. Precision medicine based on gene alteration profiling might improve the prognosis of OCCC patients.

Mucinous Cancer of the Ovary: Overview and Current Status

Mucinous ovarian cancer (MOC) is a rare subtype of epithelial ovarian carcinoma (EOC). Whereas all EOC subtypes are addressed in the same way, MOC is a distinct entity. Appreciating the pathological features and genomic profile of MOC may result in the improvement in management and, hence, the prognosis. Distinguishing primary MOC from metastatic mucinous carcinoma can be challenging but is essential. Early-stage MOC carries an excellent prognosis, with advanced disease having a poor outcome. Surgical management plays an essential role in the early stage and in metastatic disease. Chemotherapy is usually administered for stage II MOC and beyond. The standard gynecology protocol is frequently used, but gastrointestinal regimens have also been administered. As MOC is associated with multiple molecular alterations, targeted therapy could be the answer to treat this disease.

Urachal Mucinous Cystic Tumor of Low Malignant Potential with Concurrent Sigmoid Colon Adenocarcinoma

Urachal mucinous tumors are rare neoplasms with behaviour that can range from relatively benign to malignancy that can spread distantly or throughout the peritoneum as pseudomyxoma peritonei or peritoneal carcinomatosis. Here we describe a unique case of urachal mucinous cystic tumor of low malignant potential confined to an intact cyst at the dome of the urinary bladder, without rupture or peritoneal spread. The urachal mucinous tumor was an incidental finding on a staging CT scan performed for sigmoid colon adenocarcinoma. We believe that this case illustrates a potential diagnostic pitfall which could have prognostic and therapeutic implications. Due to the intestinal phenotype of these neoplasms, a urachal tumor of low malignant potential could be mistaken for metastatic spread from a colonic adenocarcinoma in the rare situation such as this case, where the two neoplasms occur concurrently.

Epithelial ovarian cancer: Evolution of management in the era of precision medicine

Ovarian cancer is the second most common cause of gynecologic cancer death in women around the world. The outcomes are complicated, because the disease is often diagnosed late and composed of several subtypes with distinct biological and molecular properties (even within the same histological subtype), and there is inconsistency in availability of and access to treatment. Upfront treatment largely relies on debulking surgery to no residual disease and platinum-based chemotherapy, with the addition of antiangiogenic agents in patients who have suboptimally debulked and stage IV disease. Major improvement in maintenance therapy has been seen by incorporating inhibitors against poly (ADP-ribose) polymerase (PARP) molecules involved in the DNA damage-repair process, which have been approved in a recurrent setting and recently in a first-line setting among women with BRCA1/BRCA2 mutations. In recognizing the challenges facing the treatment of ovarian cancer, current investigations are enlaced with deep molecular and cellular profiling. To improve survival in this aggressive disease, access to appropriate evidence-based care is requisite. In concert, realizing individualized precision medicine will require prioritizing clinical trials of innovative treatments and refining predictive biomarkers that will enable selection of patients who would benefit from chemotherapy, targeted agents, or immunotherapy. Together, a coordinated and structured approach will accelerate significant clinical and academic advancements in ovarian cancer and meaningfully change the paradigm of care.

Outcomes of non-high grade serous carcinoma after neoadjuvant chemotherapy for advanced-stage ovarian cancer: a Korean gynecologic oncology group study (OV 1708)

Background

Outcomes of patients with ovarian high-grade serous carcinoma (HGSC) treated with neoadjuvant chemotherapy (NAC) have been widely studied, but there is limited information on the outcomes of patients with non-HGSC. This study aimed to evaluate the outcomes of NAC in non-HGSC patients with advanced-stage ovarian cancer.

Methods

We conducted a retrospective cohort study of patients who underwent NAC for advanced stage non-HGSC between 2002 and 2017 in 17 institutions. Demographics, surgical outcomes, and survival rates were evaluated according to histological subtypes.

Results

A total of 154 patients were included in this study, comprising 20 cases (13.0%) of mucinous adenocarcinoma, 31 cases (20.1%) of endometrioid adenocarcinoma, 28 (18.2%) cases of clear cell carcinoma, 29 (18.8%) cases of low-grade serous carcinoma and 12 cases (7.8%) of carcinosarcoma. Complete remission/partial remission after the third cycle of NAC was achieved in 100 (64.9%) patients and optimal debulking surgery (residual disease ≤1 cm) at interval debulking surgery was achieved in 103 (66.9%) patients. The most common reason for performing NAC was high tumor burden (n = 106, 68.8%). The median progression-free survival (PFS) was 14.3 months and median overall survival (OS) was 52.9 months. In multivariate analyses, mucinous and clear cell carcinoma were negative prognostic factors for both PFS (p = 0.007 and p = 0.017, respectively) and OS (p = 0.002 and p = 0.013, respectively).

Conclusions

In this study, poor survival outcomes were observed in patients with mucinous and clear cell carcinoma undergoing NAC. Different treatment strategies are urgently required to improve survival outcomes for this disease subset.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5514-7) contains supplementary material, which is available to authorized users.

Prognostic significance of preoperative serum CEA in primary mucinous ovarian carcinoma: a retrospective cohort study

Purpose

The purpose of this study was to evaluate the prognostic significance of preoperative serum carcinoembryonic antigen (CEA) in primary mucinous ovarian carcinoma (MOC).

Patients and methods

We reviewed 57 patients with primary MOC, in whom preoperative serum CEA had been measured. All patients were treated at Peking Union Medical College Hospital between June 1996 and September 2016.

Results

Preoperative serum CEA was elevated (>5.0 ng/mL) in 10 patients (17.5%), with a median serum CEA of 9.6 ng/mL (5.4–111.7 ng/mL). CEA was significantly associated with preoperative serum cancer antigen 125 (P=0.002), surgical debulking status (P=0.015), and tumor stage (P=0.001). Univariate analysis showed that patients with elevated CEA had significantly worse overall survival (OS) than patients with normal CEA (5-year OS: 50.8% vs 91.9%, respectively; P=0.013), but there was no significant difference in progression-free survival between the two groups (P=0.307). Multivariate analysis further demonstrated that advanced stage was an independent prognostic predictor for OS (P=0.002, HR: 15.925, 95% CI: 2.745–92.404).

Conclusion

Elevated preoperative serum CEA was strongly correlated with advanced stage in primary MOC, which may indicate a poorer prognosis. Further investigation of the intrinsic relationship between CEA and primary MOC is now required.