Therapeutic Approach to Low-Grade Serous Ovarian Carcinoma: State of Art and Perspectives of Clinical Research

Outcome and prognostic factors of low‑grade serous ovarian cancer: An observational retrospective study

Low-grade serous ovarian cancer (LGSOC) is a very rare histological subtype of serous ovarian cancer, representing ~2% of all epithelial ovarian cancer cases. LGSOC has a better prognosis but a lower response rate to chemotherapy in comparison to high-grade serous ovarian carcinoma (HGSOC). The present study is a retrospective review of the medical records of all patients with histologically proven LGSOC diagnosed and treated in a single institute between January 2003 and December 2019. A total of 23 patients diagnosed with LGSOC and treated at King Faisal Specialist Hospital and Research Center (Riyadh, Saudi Arabia) were identified. The median age at diagnosis was 45.5 years (range, 26-66 years) and the median body mass index was 26.1 (range, 18-43). A total of 21 patients (91.3%) had de novo LGSOC, whereas only 2 patients (8.7%) had LGSOC that had transformed from serous borderline ovarian tumors and recurred. A total of 8 patients (34.8%) were diagnosed with International Federation of Gynecology and Obstetrics stage IV, whereas 3 (13.0%), 3 (13.0%) and 9 (39.1%) were diagnosed with stages I, II and III, respectively. In addition, 10 (43.5%), 5 (21.7%), and 3 (13.0%) patients had complete response, stable disease and partial response statuses after first-line therapy, respectively. At a median follow-up time of 34 months [95% confidence interval (CI), 25.32-42.69], the median progression-free survival (PFS) time was 75.2 months (95% CI, 17.35-133.05) and the median overall survival (OS) time was not reached. In conclusion, LGSOC exhibited better PFS and OS times than HGSOC as compared with data from the literature, and there is the option for systemic treatment (chemotherapy or hormonal therapy). Optimal cytoreduction showed numerically higher, but non-significant, PFS and OS times compared with suboptimal debulking; however, the optimal systemic chemotherapy or hormonal treatment remains controversial.

Novel Endocrine Therapeutic Opportunities for Estrogen Receptor-Positive Ovarian Cancer-What Can We Learn from Breast Cancer?

Low-grade serous ovarian cancer (LGSOC) is a rare ovarian malignancy primarily affecting younger women and is characterized by an indolent growth pattern. It exhibits indolent growth and high estrogen/progesterone receptor expression, suggesting potential responsiveness to endocrine therapy. However, treatment efficacy remains limited due to the development of endocrine resistance. The mechanisms of resistance, whether primary or acquired, are still largely unknown and present a significant hurdle in achieving favorable treatment outcomes with endocrine therapy in these patients. In estrogen receptor-positive breast cancer, mechanisms of endocrine resistance have been largely explored and novel treatment strategies to overcome resistance have emerged. Considering the shared estrogen receptor positivity in LGSOC and breast cancer, we wanted to explore whether there are any parallel mechanisms of resistance and whether we can extend endocrine breast cancer treatments to LGSOC. This review aims to highlight the underlying molecular mechanisms possibly driving endocrine resistance in ovarian cancer, while also exploring the available therapeutic opportunities to overcome this resistance. By unraveling the potential pathways involved and examining emerging strategies, this review explores valuable insights for advancing treatment options and improving patient outcomes in LGSOC, which has limited therapeutic options available.

The Role of Systematic Lymphadenectomy in Low-Grade Serous Ovarian Cancer: A Systematic Review and Meta-Analysis

OBJECTIVE

To evaluate the role of systematic lymphadenectomy in low-grade serous ovarian cancer (LGSOC) and determine its impact on clinical outcomes in overall survival (OS) and disease-free survival (DFS) terms.

METHODS

A comprehensive, systematic computer literature search on PubMed was performed using the following Medical Subject Headings (MeSH) terms: "low grade serous ovarian cancer" AND/OR "lymphadenectomy" AND/OR "staging" AND/OR "ovarian cancer" AND/OR "cytoreduction". Separate searches were performed with MeSH terms on MEDLINE and EMBASE to extract all the relevant literature available. We included only patients with histologically confirmed LGSOC.

RESULTS

Three studies were considered in the quantitative analysis. Systematic lymphadenectomy in LGSOC failed to provide a significant OS or PFS benefit in LGSOC when compared to no lymphadenectomy in the entire (all the stages) population (for OS: HR = 1.15, 95% CI [0.42, 3.18] I2 = 84% and for PFS: HR = 1.46, 95% CI [0.63, 3.41], I2 = 71%), nor did it in the subtype analysis regarding FIGO stages. For FIGO early-stage I-II LGSOC, the DFS data were pooled (HR = 1.48, 95% CI [0.58, 3.78], I2 = 75%). In patients with advanced-stage (FIGO II-IV), we also failed to prove survival benefit for lymphadenectomy in OS (HR = 1.74, 95% CI [0.87, 3.48], I2 = 11%) or DFS (HR = 1.48, 95% CI [0.58, 3.78], I2 = 75%) compared to no lymphadenectomy.

CONCLUSION

More extensive prospective research is mandatory to understand the real impact of lymphadenectomy on survival in LGSOC. The existing literature does not provide strong evidence.

Case report: ex vivo tumor organoid drug testing identifies therapeutic options for stage IV ovarian carcinoma

Patients presenting with stage 4 ovarian carcinoma, including low-grade serous disease, have a poor prognosis. Although platinum-based therapies can offer some response, these therapies are associated with many side effects, and treatment resistance often develops. Toxic side effects along with disease progression render patients unable to receive additional lines of treatment and limit their options to hospice or palliative care. In this case report, we describe a patient with an unusual case of metastatic low-grade serous ovarian cancer with some features of high-grade disease who had received four previous lines of treatment and was suffering from atelectasis, pulmonary embolism, and hydronephrosis. A CLIA-certified drug sensitivity assay of an organoid culture derived from the patient's tumor (PARIS® test) identified several therapeutic options, including the combination of fulvestrant with everolimus. On this treatment regimen, the patient experienced 7 months of stable disease and survived nearly 11 months before succumbing to her disease. This case emphasizes the clinical utility of ex vivo drug testing as a new functional precision medicine approach to identify, in real-time, personalized treatment options for patients, especially those who are not benefiting from standard of care treatments.

Drug-Resistant Epithelial Ovarian Cancer: Current and Future Perspectives

Epithelial ovarian cancer (EOC) is a complex disease with diverse histological subtypes, which, based on the aggressiveness and course of disease progression, have recently been broadly grouped into type I (low-grade serous, endometrioid, clear cell, and mucinous) and type II (high-grade serous, high-grade endometrioid, and undifferentiated carcinomas) categories. Despite substantial differences in pathogenesis, genetics, prognosis, and treatment response, clinical diagnosis and management of EOC remain similar across the subtypes. Debulking surgery combined with platinum-taxol-based chemotherapy serves as the initial treatment for High Grade Serous Ovarian Carcinoma (HGSOC), the most prevalent one, and for other subtypes, but most patients exhibit intrinsic or acquired resistance and recur in short duration. Targeted therapies, such as anti-angiogenics (e.g., bevacizumab) and PARP inhibitors (for BRCA-mutated cancers), offer some success, but therapy resistance, through various mechanisms, poses a significant challenge. This comprehensive chapter delves into emerging strategies to address these challenges, highlighting factors like aberrant miRNAs, metabolism, apoptosis evasion, cancer stem cells, and autophagy, which play pivotal roles in mediating resistance and disease relapse in EOC. Beyond standard treatments, the focus of this study extends to alternate targeted agents, including immunotherapies like checkpoint inhibitors, CAR T cells, and vaccines, as well as inhibitors targeting key oncogenic pathways in EOC. Additionally, this chapter covers disease classification, diagnosis, resistance pathways, standard treatments, and clinical data on various emerging approaches, and advocates for a nuanced and personalized approach tailored to individual subtypes and resistance mechanisms, aiming to enhance therapeutic outcomes across the spectrum of EOC subtypes.

Heterogeneity and treatment landscape of ovarian carcinoma

Ovarian carcinoma is characterized by heterogeneity at the molecular, cellular and anatomical levels, both spatially and temporally. This heterogeneity affects response to surgery and/or systemic therapy, and also facilitates inherent and acquired drug resistance. As a consequence, this tumour type is often aggressive and frequently lethal. Ovarian carcinoma is not a single disease entity and comprises various subtypes, each with distinct complex molecular landscapes that change during progression and therapy. The interactions of cancer and stromal cells within the tumour microenvironment further affects disease evolution and response to therapy. In past decades, researchers have characterized the cellular, molecular, microenvironmental and immunological heterogeneity of ovarian carcinoma. Traditional treatment approaches have considered ovarian carcinoma as a single entity. This landscape is slowly changing with the increasing appreciation of heterogeneity and the recognition that delivering ineffective therapies can delay the development of effective personalized approaches as well as potentially change the molecular and cellular characteristics of the tumour, which might lead to additional resistance to subsequent therapy. In this Review we discuss the heterogeneity of ovarian carcinoma, outline the current treatment landscape for this malignancy and highlight potentially effective therapeutic strategies in development.

Cryoglobulinemia Leading to the Diagnosis of Low Grade Serous Ovarian Carcinoma

We present the case of a 64-year-old female who was referred by her oncologist to benign hematology clinic for persistent asymptomatic cryoglobulinemia. Workup led to diagnosis of a rare low grade ovarian serous carcinoma. We briefly review the pathophysiology and clinical significance of cryoglobulinemia and the diagnosis and management of low grade serous ovarian carcinoma.

The drug efficacy testing in 3D cultures platform identifies effective drugs for ovarian cancer patients

Most patients with advanced ovarian cancer (OC) relapse and progress despite systemic therapy, pointing to the need for improved and tailored therapy options. Functional precision medicine can help to identify effective therapies for individual patients in a clinically relevant timeframe. Here, we present a scalable functional precision medicine platform: DET3Ct (Drug Efficacy Testing in 3D Cultures), where the response of patient cells to drugs and drug combinations are quantified with live-cell imaging. We demonstrate the delivery of individual drug sensitivity profiles in 20 samples from 16 patients with ovarian cancer in both 2D and 3D culture formats, achieving over 90% success rate in providing results six days after operation. In this cohort all patients received carboplatin. The carboplatin sensitivity scores were significantly different for patients with a progression free interval (PFI) less than or equal to 12 months and those with more than 12 months (p < 0.05). We find that the 3D culture format better retains proliferation and characteristics of the in vivo setting. Using the DET3Ct platform we evaluate 27 tailored combinations with results available 10 days after operation. Notably, carboplatin and A-1331852 (Bcl-xL inhibitor) showed an additive effect in four of eight OC samples tested, while afatinib and A-1331852 led to synergy in five of seven OC models. In conclusion, our 3D DET3Ct platform can rapidly define potential, clinically relevant data on efficacy of existing drugs in OC for precision medicine purposes, as well as provide insights on emerging drugs and drug combinations that warrant testing in clinical trials.

High In Vitro and In Vivo Activity of BI-847325, a Dual MEK/Aurora Kinase Inhibitor, in Human Solid and Hematologic Cancer Models

BI-847325 is an ATP-competitive inhibitor of MEK/Aurora kinases with the potential to treat a wide range of cancers. In a panel of 294 human tumor cell lines in vitro, BI-847325 was found to be a highly selective inhibitor that was active in the submicromolar range. The most sensitive cancer types were acute lymphocytic and myelocytic leukemia, melanomas, bladder, colorectal, and mammary cancers. BI-847325 showed a broader range of activity than the MEK inhibitor GDC-0623. The high efficacy of BI-847325 was associated with but not limited to cell lines with oncogenic mutations in NRAS, BRAF, and MAP2K1.The high antiproliferative activity of BI-847325 was validated in vivo using subcutaneous xenograft models. After oral administration of 80 and 40 mg/kg once weekly for 3 or 4 weeks, BI-847325 was highly active in four of five colorectal, two of two gastric, two of two mammary, and one of one pancreatic cancer models (test/control < 25%), and tumor regressions were observed in five of 11 cancer models. The treatment was well tolerated with no relevant lethality or body weight changes. In combination with capecitabine, BI-847325 displayed synergism over single-agent therapies, leading to complete remission in the triple-negative mammary model MAXFTN 401, partial regression in the colon model CXF 1103, and stasis in the gastric models GXA 3011 and GXA 3023. In conclusion, dual MEK/Aurora kinase inhibition shows remarkable potential for treating multiple types of hematologic and solid tumors. The combination with capecitabine was synergistic in colorectal, gastric, and mammary cancer.

SIGNIFICANCE

We report the preclinical evaluation of BI-847325, a MEK/Aurora kinase inhibitor. Our data demonstrate that BI-847325 has potent antitumor activity in a broad range of human solid and hematologic cancer models in vitro and in vivo and is well tolerated in animal models. It also shows synergistic effect when combined with capecitabine. These findings provide a strong rationale for further development of BI-847325 as a potential therapeutic for patients with cancer.

Hormone Receptors and Epithelial Ovarian Cancer: Recent Advances in Biology and Treatment Options

Epithelial ovarian cancer (EOC) is a significant cause of cancer-related mortality in women. Despite advances in diagnosis and treatment, EOC remains a challenging disease to manage, and the 5-year survival rate is still poor. The role of hormone receptors (HRs) in EOC carcinogenesis and prognosis has been actively explored; however, the role of hormone therapy (HT) in the treatment of these tumors is not well established. Most available data on HT mainly come from retrospective series and small early clinical trials. Several of these studies suggest that HT may have a role in adjuvant, maintenance therapy, or in the case of recurrent disease, especially for some subtypes of EOC (e.g., low-grade serous EOC). Furthermore, HT has recently been combined with targeted therapies, but most studies evaluating these combinations are still ongoing. The main aim of this review is to provide an overview of the progress made in the last decade to characterize the biological and prognostic role of HRs for EOC and the developments in their therapeutic targeting through HT.

Simultaneous p53 and KRAS mutation in a high-grade serous carcinoma with deceptive appearance of a low-grade carcinoma. A case report

Low-grade and high-grade serous carcinomas have unique clinical, morphological, underlying molecular alterations, and vastly different biologic behavior (Prat et al., 2018, Vang et al., 2009). The differentiation into high and low-grade serous carcinoma is important for clinical management and prognosis and is easily recognized by practicing pathologists. High-grade serous carcinoma is characterized by marked nuclear atypia and pleomorphism, frequent, often atypical mitosis with papillary or three-dimensional clusters, p53 mutation, and block-like p16 staining. In contrast, low-grade serous carcinomas have a different morphologic appearance with micropapillary formation, small nests of tumor cells having low to intermediate grade nuclei, and absence of significant mitosis. Low-grade serous carcinoma is often associated with micropapillary variant of ovarian serous borderline tumor. The low-grade serous carcinoma shows wild type p53 expression, patchy p16 staining, and often K-RAS, N-RAS, and/or B-RAF mutation. Here we report a case of mullerian high grade serous with a deceptive morphology resembling low-grade serous carcinoma with micropapillary features and moderate nuclear atypia. However, the tumor is simultaneously p53 and K-RAS mutated. This case illustrates three critical issues; a) potential to be mistaken as a low-grade serous carcinoma because of morphologic appearance and relative uniform cytologic feature. b). raise the question of true progression of low-grade to high-grade serous carcinoma, a rare phenomenon as described in the literature, and c). whether the biologic behavior and/or response to therapy would differ from the classic forms.

Skin Metastasis of Low-Grade Ovarian Serous Carcinoma: A Case Report

This case report, written with the assistance of ChatGPT, describes a rare manifestation of ovarian serous carcinoma that metastasized to the skin. A 30-year-old female with a history of stage IV low-grade serous ovarian carcinoma presented for evaluation of a painful nodule on her back. Physical examination demonstrated a round, firm, mobile subcutaneous nodule on the left upper back. An excisional biopsy was performed, and histopathologic examination was consistent with metastatic ovarian serous carcinoma. This case highlights the clinical presentation, histopathology, and treatment of cutaneous metastasis of serous ovarian carcinoma. Additionally, this case highlights the value and technique of using ChatGPT to assist in writing medical case reports including outlining, referencing, summarizing studies, and formatting citations.

Functional estrogen receptor signal transduction pathway activity and antihormonal therapy response in low-grade ovarian carcinoma

BACKGROUND

Advanced low-grade ovarian carcinoma (LGOC) is difficult to treat. In several studies, high estrogen receptor (ER) protein expression was observed in patients with LGOC, which suggests that antihormonal therapy (AHT) is a treatment option. However, only a subgroup of patients respond to AHT, and this response cannot be adequately predicted by currently used immunohistochemistry (IHC). A possible explanation is that IHC only takes the ligand, but not the activity, of the whole signal transduction pathway (STP) into account. Therefore, in this study, the authors assessed whether functional STP activity can be an alternative tool to predict response to AHT in LGOC.

METHODS

Tumor tissue samples were obtained from patients with primary or recurrent LGOC who subsequently received AHT. Histoscores of ER and progesterone receptor (PR) were determined. In addition, STP activity of the ER STP and of six other STPs known to play a role in ovarian cancer was assessed and compared with the STP activity of healthy postmenopausal fallopian tube epithelium.

RESULTS

Patients who had normal ER STP activity had a progression-free survival (PFS) of 16.1 months. This was significantly shorter in patients who had low and very high ER STP activity, with a median PFS of 6.0 and 2.1 months, respectively (p < .001). Unlike ER histoscores, PR histoscores were strongly correlated to the ER STP activity and thus to PFS.

CONCLUSIONS

Aberrant low and very high functional ER STP activity and low PR histoscores in patients with LGOC indicate decreased response to AHT. ER IHC is not representative of functional ER STP activity and is not related to PFS.

Molecular characteristics of low-grade serous carcinoma in effusions

OBJECTIVE

The molecular characteristics of low-grade serous carcinoma (LGSC) in serous effusions have not been studied previously. The present study analysed the molecular profile of LGSC at this anatomical site.

METHODS

Specimens consisted of a series of 17 serous effusions (15 peritoneal, 2 pleural) from 16 patients, of which 15 were LGSC and 2 serous borderline tumour (SBT) who later progressed to LGSC. For comparative purposes, 9 surgical specimens from 6 patients with LGSC were analysed. Fresh-frozen cell pellets and surgical specimens underwent targeted next-generation sequencing covering 50 unique genes.

RESULTS

Mutations were found in tumours from 14 of the 22 patients, of whom 4 had 2 different mutations and 10 had a single mutation. Overall, the most common mutations were in KRAS (n = 3) and BRAF (n = 3), followed by NRAS (n = 2), CDK2NA (n = 2), TP53 (n = 2), ATM (n = 2). Mutations in MET, STK11, ERBB2 and FLT3 were found in one case each. Patient-matched specimens had the same molecular profile. Both effusions with TP53 mutation had concomitant ATM mutation, and both stained immunohistochemically with a wild-type pattern. The absence of mutations was associated with a trend for shorter overall survival in univariate analysis (p = 0.072).

CONCLUSIONS

The molecular alterations in LGSCs in serous effusions are consistent with those found in solid tumours, with frequent alterations in the mitogen-activated protein kinase pathway. Mutations in LGSC may be a marker of better outcomes.

Evaluation of the prognostic value of lymphadenectomy for low-grade serous ovarian cancer: A case-control multicenter retrospective study

BACKGROUND

The prognostic value of lymphadenectomy in low-grade serous ovarian cancer (LGSOC) remains uncertain.

MATERIALS AND METHODS

A retrospective analysis of 155 patients with LGSOC who underwent surgery over a ten-year period (2011-2020) was performed. The propensity score matching (PSM) algorithm was performed between the lymphadenectomy and no lymphadenectomy groups, and Kaplan-Meier analyses were conducted to evaluate clinical prognosis. Finally, univariate and multivariate Cox proportional hazards regression analyses were performed to analyze high-risk factors associated with clinical prognosis.

RESULTS

In the pre-PSM cohort, 110 (71.0%) patients underwent lymphadenectomy. Of these, 54 (34.8%) experienced recurrence, and 27 (17.4%) died. There were statistical differences in disease-free survival (DFS) (P = 0.018) and overall survival (OS) (P = 0.016) in the post-PSM cohort. In the subgroup analysis, there were no statistically significant differences in DFS (P = 0.449) or OS (P = 0.167) in the FIGO I/II cohort. However, in the FIGO III/IV cohort, DFS (P = 0.011) and OS (P = 0.046) were statistically different between the two groups. Age > 50 years, FIGO stage III/IV, and suboptimal cytoreductive surgery were risk factors associated with prognosis. In the lymphadenectomy group, the histological status of pelvic lymph nodes had no significant effect on DFS (P = 0.205) or OS (P = 0.114).

CONCLUSION

Lymphadenectomy was associated with DFS and OS, particularly in patients with advanced LGSOC patients. Age > 50 years, advanced FIGO stage III/IV, and suboptimal cytoreductive surgery were high-risk factors associated with clinical prognosis in patients with LGSOC.

Traditional Systemic Treatment Options in Advanced Low-Grade Serous Ovarian Cancer after Successful Cytoreduction: A Systematic Review and Meta-Analysis

Simple Summary

Low-Grade Serous Ovarian cancer (LGSOC) is considered less sensitive to traditional chemotherapy than its high-grade counterpart. Guidelines are still inconsistent around the use and value of cytotoxic and antihormonal agents in the adjuvant setting. Traditional cytotoxic or antihormonal systemic treatment option is not associated with a significant OS or PFS benefit in this Meta-analysis.

Abstract

Objective: We performed a systematic literature review and a subsequent meta-analysis to compare traditional treatment options, i.e., antihormonal and cytotoxic, in LGSOC. Methods: We conducted a systematic literature review in MEDBASE and MEDLINE between September 2000 and June 2021 for women who received cytotoxic chemotherapy and/or antihormonal treatment after primary cytoreduction due to stage II–IV LGSOC and also at relapse. PFS and OS were calculated depending on the type of their adjuvant treatment. For each endpoint in the meta-analysis, pooled HR was calculated using the random effect model with the inverse variance weighted method. Only primary patients were included in the subsequent meta-analysis due to the small number of studies in the relapsed setting. Results: Five eligible first-line studies were included. Systemic chemotherapy failed to provide a significant OS benefit when compared to no systemic treatment (pooled HR = 1.01, 95% CI [0.79, 1.29]) after successful cytoreduction. Moreover, systemic chemotherapy followed by antihormonal treatment also did not result to a significant PFS or OS benefit when compared to systemic chemotherapy alone (for PSF: pooled HR = 0.59, 95% CI [0.33, 1.04]; for OS: pooled HR = 0.83, 95% CI [0.50, 1.39]). There were insufficient data from studies in the recurrent setting to allow their inclusion in the meta-analysis. Conclusions: In this meta-analysis, we failed to identify a traditional cytotoxic or antihormonal systemic treatment option that was associated with a significant OS or PFS benefit when administered following successful cytoreduction for advanced LGSOC. Prospective randomized studies are urgently warranted to define optimal adjuvant options in this challenging disease.

Single-Cell Proteomics Analysis of Recurrent Low-Grade Serous Ovarian Carcinoma and Associated Brain Metastases

Between 2% and 6% of epithelial ovarian cancer (EOC) patients develop brain metastases (brain mets), which are incurable and invariably result in death. This poor outcome is associated with a lack of established guidelines for the detection and treatment of brain mets in EOC patients. In this study, we characterize an unusual case of low-grade serous ovarian carcinoma (LGSOC) that metastasized to the brain. Using a spatially oriented single-cell proteomics platform, we compared sequential biopsies of a primary tumor with a peritoneal recurrence and brain mets. We identified several targetable oncogenic pathways and immunosuppressive mechanisms that are amplified in the brain mets and could be involved in the progression of LGSOC to the brain. Furthermore, we were able to identify cell populations that are shared between the primary tumor and the brain mets, suggesting that cells that have a propensity for metastasis to the brain could be identified early during the course of disease. Taken together, our findings further a path for personalized therapeutic decisions in LGSOC.

Novel Therapies in Gynecologic Cancer

During the past decade, considerable strides have been made in the understanding and treatment of gynecologic cancers. The advent of PARP inhibitors, antiangiogenic therapies, immunotherapy combinations, and targeted agents have altered the standard of care in ovarian, endometrial, and cervical cancers. However, continued advancement in the treatment of gynecologic cancers is critical. Fortunately, exciting work defining new therapeutic targets and novel treatment strategies is on the horizon. Here, we discuss emerging treatments for gynecologic cancers, including endometrial, cervical, ovarian, and rare gynecologic cancers. We highlight research that has deepened our understanding of the unique biology and molecular underpinnings of these cancers and is being translated into powerful new treatment approaches. We particularly highlight the advent of immunotherapy in endometrial cancer; radiosensitizers in cervical, vaginal, and vulvar cancers; targeted therapies in ovarian cancer; and molecularly driven approaches to treat rare gynecologic cancers. Continued basic, translational, and clinical research holds the promise to change the landscape of gynecologic cancer and improve the lives of all women impacted by these diseases.

Clinicopathologic prognostic parameters in patients with tubo‐ovarian carcinoma effusions

Objective

To analyse the predictive and prognostic role of clinicopathological parameters in patients with tubo‐ovarian carcinoma and malignant effusion.

Methods

A retrospective series of 700 malignant peritoneal (n = 610) and pleural (n = 90) effusions from 558 patients was revised for histotype based on the 2014 World Health Organization criteria. The role of clinicopathological parameters in determining outcome was assessed.

Results

The majority of specimens (597 effusions from 473 patients) were high‐grade serous carcinomas (HGSC), followed by low‐grade serous carcinoma (LGSC; 48 effusions, 37 patients), clear cell carcinoma (CCC; 23 effusions, 19 patients) and carcinosarcoma (CS; 16 effusions, 16 patients). Patients with CCC and CS had the shortest, those with HGSC intermediate, and those with LGSC longest overall and progression‐free survival (both P < 0.001). For patients with HGSC, older age (P = 0.002), more advanced FIGO stage (IV vs III; P < 0.001), delayed/no surgery (P < 0.001), larger residual disease volume (RD; P < 0.001), non‐complete response to chemotherapy at diagnosis (P < 0.001), and primary platinum resistance (P < 0.001) were associated with shorter overall survival. In Cox multivariate analysis, FIGO stage (P = 0.002) and primary platinum resistance (P < 0.001) were independent prognosticators. Significant association was additionally found for parameters analysed for progression‐free survival in HGSC (previous chemotherapy: P = 0.029; age: P = 0.046; FIGO stage, upfront therapy, RD: P < 0.001), of which previous chemotherapy, upfront therapy, and RD were independent prognosticators (all P < 0.001).

Conclusions

The vast majority of malignant effusions in patients with tubo‐ovarian carcinoma are derived from serous carcinoma or related tumours, such as CS. Histology is a powerful prognostic factor in this patient group, as are established clinical parameters.

Impressive and durable clinical responses obtained with dabrafenib and trametinib in low-grade serous ovarian cancer harbouring a BRAF V600E mutation

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LGSOC is characterized scarce therapeutic options in the advanced setting.

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BRAF mutations are frequent on these types of tumours.

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Dabrafenib/trametinib yield impressive responses in patients with BRAF mutations.

Low-grade serous ovarian cancer (LGSOC) is now considered a different entity from high-grade serous ovarian cancer. The chemoresistance inherent to this type of ovarian cancer narrows the therapeutic options, especially in the recurrent setting. It is thought that the mitogen-activated protein kinase (MAPK) pathway plays a significant role in the pathogenesis of these tumours, and about 2 to 20% of LGSOC harbour a BRAF mutation. Here we present a case report of two patients with a BRAF V600E mutation that achieved sustained clinical responses with combination treatment with dabrafenib (BRAF inhibitor) and trametinib (MEK inhibitor).

Patient-derived tumor models are attractive tools to repurpose drugs for ovarian cancer treatment: Pre-clinical updates

Despite advances in understanding of ovarian cancer biology, the progress in translation of research findings into new therapies is still slow. It is associated in part with limitations of commonly used cancer models such as cell lines and genetically engineered mouse models that lack proper representation of diversity and complexity of actual human tumors. In addition, the development of de novo anticancer drugs is a lengthy and expensive process. A promising alternative to new drug development is repurposing existing FDA-approved drugs without primary oncological purpose. These approved agents have known pharmacokinetics, pharmacodynamics, and toxicology and could be approved as anticancer drugs quicker and at lower cost. To successfully translate repurposed drugs to clinical application, an intermediate step of pre-clinical animal studies is required. To address challenges associated with reliability of tumor models for pre-clinical studies, there has been an increase in development of patient-derived xenografts (PDXs), which retain key characteristics of the original patient’s tumor, including histologic, biologic, and genetic features. The expansion and utilization of clinically and molecularly annotated PDX models derived from different ovarian cancer subtypes could substantially aid development of new therapies or rapid approval of repurposed drugs to improve treatment options for ovarian cancer patients.

Platinum-resistant ovarian cancer: From drug resistance mechanisms to liquid biopsy-based biomarkers for disease management

Resistance to platinum-based chemotherapy is a major clinical challenge in ovarian cancer, contributing to the high mortality-to-incidence ratio. Management of the platinum-resistant disease has been difficult due to diverse underlying molecular mechanisms. Over the past several years, research has revealed several novel molecular targets that are being explored as biomarkers for treatment planning and monitoring of response. The therapeutic landscape of ovarian cancer is also rapidly evolving, and alternative therapies are becoming available for the recurrent platinum-resistant disease. This review provides a snapshot of platinum resistance mechanisms and discusses liquid-based biomarkers and their potential utility in effective management of platinum-resistant ovarian cancer.

(In)Distinctive Role of Long Non-Coding RNAs in Common and Rare Ovarian Cancers

Rare ovarian cancers (ROCs) are OCs with an annual incidence of fewer than 6 cases per 100,000 women. They affect women of all ages, but due to their low incidence and the potential clinical inexperience in management, there can be a delay in diagnosis, leading to a poor prognosis. The underlying causes for these tumors are varied, but generally, the tumors arise due to alterations in gene/protein expression in cellular processes that regulate normal proliferation and its checkpoints. Dysregulation of the cellular processes that lead to cancer includes gene mutations, epimutations, non-coding RNA (ncRNA) regulation, posttranscriptional and posttranslational modifications. Long non-coding RNA (lncRNA) are defined as transcribed RNA molecules, more than 200 nucleotides in length which are not translated into proteins. They regulate gene expression through several mechanisms and therefore add another level of complexity to the regulatory mechanisms affecting tumor development. Since few studies have been performed on ROCs, in this review we summarize the mechanisms of action of lncRNA in OC, with an emphasis on ROCs.

Estrogens and the Schrödinger's Cat in the Ovarian Tumor Microenvironment

Simple Summary

Ovarian cancer is a complex pathology for which we require effective screening and therapeutical strategies. Apart from the cancer cell portion, there exist plastic immune and non-immune cell populations, jointly constituting the context-adaptive tumor microenvironment, which is pivotal in tumorigenesis. Estrogens might be synthesized in the ovarian tumor tissue and actively contribute to the shaping of an immunosuppressive microenvironment. Current immune therapies have limited effectiveness as a multitude of factors influence the outcome. A thorough understanding of the ovarian cancer biology is crucial in the efforts to reestablish homeostasis.

Abstract

Ovarian cancer is a heterogeneous disease affecting the aging ovary, in concert with a complex network of cells and signals, together representing the ovarian tumor microenvironment. As in the “Schrödinger’s cat” thought experiment, the context-dependent constituents of the—by the time of diagnosis—well-established tumor microenvironment may display a tumor-protective and -destructive role. Systemic and locally synthesized estrogens contribute to the formation of a pro-tumoral microenvironment that enables the sustained tumor growth, invasion and metastasis. Here we focus on the estrogen biosynthetic and metabolic pathways in ovarian cancer and elaborate their actions on phenotypically plastic, estrogen-responsive, aging immune cells of the tumor microenvironment, altogether highlighting the multicomponent-connectedness and complexity of cancer, and contributing to a broader understanding of the ovarian cancer biology.

Low-grade serous epithelial ovarian cancer: a comprehensive review and update for radiologists

Low-grade serous carcinoma (LGSC) is an infrequent subtype of ovarian cancer, corresponding to 5% of epithelial neoplasms. This subtype of ovarian carcinoma characteristically has molecular features, pathogenesis, clinical behaviour, sensitivity to chemotherapy, and prognosis distinct to high-grade serous carcinoma (HGSC). Knowing the difference between LGSC and other ovarian serous tumours is vital to guide clinical management, which currently is only possible histologically. However, imaging can provide several clues that allow differentiating LGSC from other tumours and enable precise staging and follow-up of ovarian cancer treatment. Characteristically, LGSC appears as mixed lesions with variable papillary projections and solid components, usually in different proportions from those detected in serous borderline tumour and HGSC. Calcified extracellular bodies, known as psammoma bodies, are also a common feature of LGSC, frequently detectable within lymphadenopathies and metastases associated with this type of tumour. In addition, the characterisation of magnetic resonance imaging enhancement also plays an essential role in calculating the probability of malignancy of these lesions. As such, in this review, we discuss and update the distinct radiological modalities features and the clinicopathologic characteristics of LGSC to allow radiologists to be familiarised with them and to narrow the differential diagnosis when facing this type of tumour.

miR-4461 Regulates the Proliferation and Metastasis of Ovarian Cancer Cells and Cisplatin Resistance

microRNAs (miRNAs) are of great significance in cancer treatment, which may have a desirable result on the regulation of tumorigenesis, progression, recurrence, and chemo-resistance of ovarian cancer. However, the research on the further potential application of miR-4461 in ovarian cancer is little and limited. Therefore, the study in this paper focus on the investigation of the of miR-4461 in ovarian cancer progression and chemo-resistance. The phenomenon that the proliferation and metastasis of ovarian cancer cells can be promoted by miR4461 is revealed in functional assays. Through the bioinformatics and luciferase reporter analysis, the PTEN is validated to be the direct target of miR-4461 in ovarian. The association between the expression of miR-4461 and PTEN is negative in in human ovarian cancer tissues. The distinction of growth and metastasis capacity between miR-4461 knockdown ovarian cancer cells and control cells is partially abolished by si-PTEN. Moreover, it was found that cisplatin treatment has obvious effect on the miR-4461 knockdown ovarian cancer cells. In summary, the data given in this paper indicate that the miR-4461 can be regarded as a potential onco-miRNA in ovarian cancer by targeting PTEN.

Complete response with combined BRAF and MEK inhibition in BRAF mutated advanced low-grade serous ovarian carcinoma

More effective treatments are needed for low-grade serous ovarian carcinoma (LGSOC). Our patient, who suffers from metastatic LGSOC, had received all established treatments. Sequencing analysis revealed an activating BRAF mutation. Therefore, combined treatment with BRAF and MEK inhibitors, which is the gold standard in malignant melanoma, was initiated. After eight months of therapy, the response was assessed as complete and the treatment is still, 3.5 years after initiation, of benefit. To our knowledge, no complete response on combined BRAF and MEK inhibitor treatment of low-grade serous ovarian cancer has previously been reported.