Low-grade serous carcinoma: New concepts and emerging therapies

Targeting BRAF pathway in low-grade serous ovarian cancer

Mutations in genes encoding for proteins along the RAS-RAF-MEK-ERK pathway have been detected in a variety of tumor entities including ovarian carcinomas. In the recent years, several inhibitors of this pathway have been developed, whose antitumor potential is currently being assessed in different clinical trials. Low grade serous ovarian carcinoma, is a rare gynecological tumor which shows favorable overall survival, compared to the general ovarian cancer population, but worrying resistance to conventional chemotherapies. The clinical behavior of low grade serous ovarian carcinoma reflects the different gene profile compared to high-grade serous carcinoma: KRAS/BRAF mutations. BRAF inhibitors as single agents were approved for the treatment of BRAF mutated tumors. Nevertheless, many patients face progressive disease. The understanding of the mechanisms of resistance to BRAF inhibitors therapy and preclinical studies showing that BRAF and mitogen-activated protein kinase kinase (MEK) inhibitors combined therapy delays the onset of resistance compared to BRAF inhibitor single agent, led to the clinical investigation of combined therapy. The aim of this paper is to review the efficacy and safety of the combination of BRAF plus MEK inhibitors on ovarian carcinomas, in particularly focusing on low grade serous ovarian carcinoma.

Exploring novel approaches in the systemic therapy of low-grade serous carcinoma of the ovary: a literature review

By presenting a comprehensive analysis of low-grade serous carcinomas (LGSCs), a subset of epithelial ovarian cancers, this review delves into their distinct molecular characteristics, clinicopathological features and systemic therapy options, emphasizing their differences from high-grade serous carcinomas (HGSCs). Notably, LGSCs exhibit prevalent RAS/RAF/MEK/MAPK pathway activation, KRAS and BRAF mutations, and infrequent p53 mutations. While chemotherapy is commonly employed, LGSCs display lower responsiveness compared to HGSCs. Hormone therapy, particularly endocrine maintenance therapy, is explored due to the higher estrogen receptor expression. Novel therapeutic approaches involving CDK4/6 inhibitors, MEK inhibitors, and antiangiogenic agents like bevacizumab are also investigated. Ongoing clinical trials are striving to enhance LGSC treatment strategies, offering valuable insights for future therapeutic advancements in this challenging ovarian cancer subtype.

Advances in precision therapy of low-grade serous ovarian cancer: A review

Low-grade serous ovarian carcinoma (LGSOC) is a rare subtype of ovarian cancer that accounts for approximately 6% to 10% of serous ovarian cancers. The clinical treatment of LGSOC is similar to that of high-grade serous ovarian carcinoma, however, its clinical and molecular characteristics are different from those of high-grade serous ovarian carcinoma. This article reviews the research on gene diagnosis, surgical treatment, chemotherapy, and biological therapy of LGSOC, providing reference for clinical diagnosis and treatment of LGSOC. Surgery is the cornerstone of LGSOC treatment and maximum effort must be made to achieve R0 removal. Although LGSOC is not sensitive to chemotherapy, postoperative platinum-based combination chemotherapy remains the first-line treatment option for LGSOC. Additional clinical trials are needed to confirm the clinical benefits of chemotherapy and explore new chemotherapy protocols. Hormone and targeted therapies may also play important roles. Some patients, particularly those with residual lesions after treatment, may benefit from hormone maintenance therapy after chemotherapy. Targeted therapies, such as MEKi, show good application prospects and are expected to change the treatment pattern of LGSOC. Continuing to further study the genomics of LGSOC, identify its specific gene changes, and combine traditional treatment methods with precision targeted therapy based on second-generation sequencing may be the direction for LGSOC to overcome the treatment bottleneck. In future clinical work, comprehensive genetic testing should be carried out for LGSOC patients to accumulate data for future scientific research, in order to find more effective methods and drugs for the treatment of LGSOC.

Complexity of the Genetic Background of Oncogenesis in Ovarian Cancer-Genetic Instability and Clinical Implications

Ovarian cancer is a leading cause of death among women with gynecological cancers, and is often diagnosed at advanced stages, leading to poor outcomes. This review explores genetic aspects of high-grade serous, endometrioid, and clear-cell ovarian carcinomas, emphasizing personalized treatment approaches. Specific mutations such as TP53 in high-grade serous and BRAF/KRAS in low-grade serous carcinomas highlight the need for tailored therapies. Varying mutation prevalence across subtypes, including BRCA1/2, PTEN, PIK3CA, CTNNB1, and c-myc amplification, offers potential therapeutic targets. This review underscores TP53's pivotal role and advocates p53 immunohistochemical staining for mutational analysis. BRCA1/2 mutations' significance as genetic risk factors and their relevance in PARP inhibitor therapy are discussed, emphasizing the importance of genetic testing. This review also addresses the paradoxical better prognosis linked to KRAS and BRAF mutations in ovarian cancer. ARID1A, PIK3CA, and PTEN alterations in platinum resistance contribute to the genetic landscape. Therapeutic strategies, like restoring WT p53 function and exploring PI3K/AKT/mTOR inhibitors, are considered. The evolving understanding of genetic factors in ovarian carcinomas supports tailored therapeutic approaches based on individual tumor genetic profiles. Ongoing research shows promise for advancing personalized treatments and refining genetic testing in neoplastic diseases, including ovarian cancer. Clinical genetic screening tests can identify women at increased risk, guiding predictive cancer risk-reducing surgery.

The Challenges and Prospects of p53-Based Therapies in Ovarian Cancer

It has been well established that mutations in the tumor suppressor gene, p53, occur readily in a vast majority of cancer tumors, including ovarian cancer. Typically diagnosed in stages three or four, ovarian cancer is the fifth leading cause of death in women, despite accounting for only 2.5% of all female malignancies. The overall 5-year survival rate for ovarian cancer is around 47%; however, this drops to an abysmal 29% for the most common type of ovarian cancer, high-grade serous ovarian carcinoma (HGSOC). HGSOC has upwards of 96% of cases expressing mutations in p53. Therefore, wild-type (WT) p53 and p53-based therapies have been explored as treatment options via a plethora of drug delivery vehicles including nanoparticles, viruses, polymers, and liposomes. However, previous p53 therapeutics have faced many challenges, which have resulted in their limited translational success to date. This review highlights a selection of these historical p53-targeted therapeutics for ovarian cancer, why they failed, and what the future could hold for a new generation of this class of therapies.

Genomic profiling in low grade serous ovarian cancer: Identification of novel markers for disease diagnosis and therapy

OBJECTIVES

Low grade serous ovarian cancer (LGSOC) differs from high grade serous in terms of pathogenesis, molecular, genetic, and clinical features. Molecular studies have been hampered by small sample sizes, heterogenous histology, and lack of comprehensive testing. We sought to molecularly profile LGSOC in a homogenously tested, histologically confirmed cohort.

METHODS

Using hot-spot and whole exome next generation sequencing (NGS), fusion gene analysis interrogating RNA, fragment analysis, in situ hybridization and/or immunohistochemistry, 179 specimens were evaluated by Caris Life Sciences (Phoenix, AZ). A second independent histologic review confirmed histology in 153 specimens.

RESULTS

Most frequently mutated genes (5% or greater) were members of the mitogen-activated protein kinase (MAPK) pathway: KRAS (23.7%, n = 36), NRAS (11.2%, n = 19), NF1 (7.9%, n = 5), and BRAF (6.6%, n = 10). Class III mutations were seen in 3 of 10 BRAF mutations while 7 were Class I V600E. Overall, estrogen and progesterone receptor expression was 80.2% (n = 130) and 27.8% (n = 45), respectively. Of those that were hormone negative, nearly 50% contained KRAS or NF1 mutations. None were NRAS mutated. Markers of response to immunotherapy were low to absent.

CONCLUSION

BRAF mutations were seen to be lower than those traditionally reported. With increased MAPK activation resulting in ligand independent activation of ERα, a role of combination therapy with hormonal and targeted therapy should be considered as 49.2% of hormone negative specimens were KRAS or NF1 mutated. Absence of immunotherapy biomarkers suggest limited benefit to immunotherapeutic agents.

Surgical Implications of Advanced Low-Grade Serous Ovarian Cancer: Analysis of the Database of the Tumeurs Malignes Rares Gynécologiques Network

Simple Summary

Low-grade serous carcinoma is a recent entity. The surgical management of advanced stages is modeled on that of high-grade tumors, with the use of neoadjuvant chemotherapy in the case of carcinosis not amenable to complete primary resection. We retrospectively analyzed data from the French national network dedicated to rare gynecologic tumors. We compared disease extension, surgical characteristics, postoperative course and survival after primary surgery vs. interval debulking. Carcinosis was more extended in the case of neoadjuvant chemotherapy. However, chemotherapy did not reduce surgical complexity, nor late postoperative morbidity. Surprisingly, progression-free and overall survival were similar after complete macroscopic or minimal resection (residuals < 2.5 mm). Survival was similar in the case of residuals ≥2.5 mm or more and nonoperated patients. Neoadjuvant chemotherapy does not improve the resectability of advanced low-grade serous cancers. Primary cytoreduction with complete or with minimal residuals should be preferred when feasible.

Abstract

The surgical specificities of advanced low-grade serous ovarian carcinoma (LGSOC) have been little investigated. Our objective was to describe surgical procedures/complications in primary (PDS) compared to interval debulking surgery (neoadjuvant chemotherapy and interval debulking surgery, NACT-IDS) and to assess the survival (progression-free (PFS) and overall survival (OS)) in patients with advanced LGSOC. We retrospectively analyzed advanced LGSOC from a nationwide registry (January 2000 to July 2017). A total of 127 patients were included (48% PDS and 35% NACT-IDS). Peritoneal carcinomatosis was more severe (p = 0.01 to 0.0001, according to sites), surgery more complex (p = 0.03) and late postoperative morbidity more frequent (p = 0.03) and more severe in the NACT-IDS group. PFS and OS were similar in patients with CC0 and CC1 residual disease after PDS or IDS. Prognosis was poorest for NACT-IDS patients with CC2/CC3 resection (PFS: HR = 2.31, IC95% (1.3–4.58); p = 0.005; OS: HR = 4.98, IC95% (1.59–15.61); p = 0.006). NACT has no benefit in terms of surgical outputs in patients with advanced LGSOC. Patients with complete resection or minimal residual disease (CC0 and CC1) have similar prognoses. On the other hand, patients with CC2 and more residual disease have similar survival rates compared to nonoperated patients. Primary cytoreduction with complete or with minimal residuals should be preferred when feasible.

Current update on malignant epithelial ovarian tumors

Epithelial ovarian cancer (EOC) represents the most frequently occurring gynecological malignancy, accounting for more than 70% of ovarian cancer deaths. Preoperative imaging plays an important role in assessing the extent of disease and guides the next step in surgical decision-making and operative planning. In this article, we will review the multimodality imaging features of various subtypes of EOC. We will also discuss the role of imaging in the staging, management, and surveillance of EOC.

Clinical factors associated with prognosis in low-grade serous ovarian carcinoma: experiences at two large academic institutions in Korea and Taiwan

Low-grade ovarian serous carcinoma (LGSOC) has clinical features different from high-grade serous ovarian carcinoma (HGSOC) accounting for the majority of epithelial ovarian cancer. Because of its rarity, previous studies have only focused on the high-grade disease without considering the differences between the two subtypes. This study aimed to evaluate the effect of the clinical prognostic factors known for HGSOC on survival in patients with LGSOC. Based on the Federation of Gynecology and Obstetrics (FIGO) stage, progression-free survival (PFS) was markedly decreased in advanced disease compared with early disease. For stage I, patients with stage IC had poorer survival than those with stage IA and IB regardless of the number of cycles of adjuvant chemotherapy. For advanced disease, no gross residual disease after primary cytoreductive surgery was significantly associated with longer PFS when compared with gross residual disease. In multivariate analysis for PFS and overall survival (OS), age, preoperative CA-125, time interval from surgery to chemotherapy, and the number of cycles of adjuvant chemotherapy were not associated with prognosis. Complete cytoreduction was the only independent prognostic factor for PFS (HR 2.45, p = 0.045). Our study revealed that the known prognostic factors in HGSOC did not show any effect on the survival in LGSOC except for FIGO stage and complete cytoreduction.

The Role of GDF15 in Regulating the Canonical Pathways of the Tumor Microenvironment in Wild-Type p53 Ovarian Tumor and Its Response to Chemotherapy

Simple Summary

Patients with wild-type p53 ovarian cancer appear to have a poorer survival rate than those with mutant p53 due to resistance to chemotherapy. The mechanism underlying this observation is not clearly understood. The aim of this study was to identify potential biomarkers regulated by p53 that conferred resistance using in vitro and in vivo studies. Growth differentiation factor 15 (GDF15) expression was demonstrated to be controlled by p53 in both ovarian cancer cell lines and orthotopic mouse models. The histological and RNAseq studies of the GDF15-knocked down, A2780 cell line-induced tumor revealed that the ratio and canonical pathways of stromal/tumor were modified by secretory GDF15.

Abstract

Background: The standard treatment of ovarian cancer is surgery followed by a chemotherapeutic combination consisting of a platinum agent, such as cisplatin and a taxane-like paclitaxel. We previously observed that patients with ovarian cancer wild-type for p53 had a poorer survival rate than did those with p53 mutations. Thus, a better understanding of the molecular changes of epithelial ovarian cancer cells with wild-type p53 in response to treatment with cisplatin could reveal novel mechanisms of chemoresistance. Methods: Gene expression profiling was performed on an ovarian cancer cell line A2780 with wild-type p53 treated with cisplatin. A gene encoding a secretory protein growth differentiation factor 15 (GDF15) was identified to be highly induced by cisplatin treatment in vitro. This was further validated in a panel of wild-type and mutant p53 ovarian cancer cell lines, as well as in mouse orthotopic models. The mouse tumor tissues were further analyzed by histology and RNA-seq. Results: GDF15 was identified as one of the highly induced genes by cisplatin or carboplatin in ovarian cancer cell lines with wild-type p53. The wild-type p53-induced expression of GDF15 and GDF15-confered chemotherapy resistance was further demonstrated in vitro and in vivo. This study also discovered that GDF15-knockdown (GDF15-KD) tumors had less stromal component and had different repertoires of activated and inhibited canonical pathways in the stromal cell and cancer cell components from that of the control tumors after cisplatin treatment. Conclusions: GDF15 expression from the wild-type p53 cancer cells can modulate the canonical pathways in the tumor microenvironment in response to cisplatin, which is a possible mechanism of chemoresistance.

Novel gene signatures for prognosis prediction in ovarian cancer

Ovarian cancer (OV) is one of the leading causes of cancer deaths in women worldwide. Late diagnosis and heterogeneous treatment result to poor survival outcomes for patients with OV. Therefore, we aimed to develop novel biomarkers for prognosis prediction from the potential molecular mechanism of tumorigenesis. Eight eligible data sets related to OV in GEO database were integrated to identify differential expression genes (DEGs) between tumour tissues and normal. Enrichment analyses discovered DEGs were most significantly enriched in G2/M checkpoint signalling pathway. Subsequently, we constructed a multi‐gene signature based on the LASSO Cox regression model in the TCGA database and time‐dependent ROC curves showed good predictive accuracy for 1‐, 3‐ and 5‐year overall survival. Utility in various types of OV was validated through subgroup survival analysis. Risk scores formulated by the multi‐gene signature stratified patients into high‐risk and low‐risk, and the former inclined worse overall survival than the latter. By incorporating this signature with age and pathological tumour stage, a visual predictive nomogram was established, which was useful for clinicians to predict survival outcome of patients. Furthermore, SNRPD1 and EFNA5 were selected from the multi‐gene signature as simplified prognostic indicators. Higher EFNA5 expression or lower SNRPD1 indicated poorer outcome. The correlation between signature gene expression and clinical characteristics was observed through WGCNA. Drug‐gene interaction was used to identify 16 potentially targeted drugs for OV treatment. In conclusion, we established novel gene signatures as independent prognostic factors to stratify the risk of OV patients and facilitate the implementation of personalized therapies.

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.

Diagnosis-shift between low-grade serous ovarian cancer and serous borderline ovarian tumor: A population-based study

OBJECTIVE

To determine changes in the characteristics of low-grade serous ovarian cancer (LGSOC) and serous borderline ovarian tumor (serous-BOT) in a time-specific manner.

METHODS

We conducted a population-based retrospective study examining the Surveillance, Epidemiology, and End Results Program from 1988 to 2000. Trends, demographics, and outcomes of 775 women with well-differentiated serous ovarian cancer, used as a surrogate for LGSOC, were compared to 3937 women with serous-BOT.

RESULTS

In the multivariable analysis, women with LGSOC were more likely to be older, have stage II-IV disease, and have undergone hysterectomy at surgery, but less likely to be a Western U.S. resident compared to those with serous-BOT (all, adjusted-P < 0.05). During the study period, the number of LGSOCs decreased by 25.9%, particularly stage I disease (37.6% relative decrease) compared to stage II-IV disease (21.1% relative decrease) (all, P < 0.05). With a median follow-up of 16.9 years, there was a decreasing trend in the 15-year overall survival rates among LGSOC (28.7% relative decrease, P = 0.056) but not in serous-BOT (2.5% relative increase, P = 0.416) as a whole cohort. The magnitude of hazard risk from all-cause death for women with LGSOC compared to those with serous-BOT increased by 68.9% from 1988 to 2000 (P < 0.001). LGSOC remained an independent prognostic factor for decreased overall survival compared to serous-BOT (adjusted-P < 0.05).

CONCLUSION

Our study suggests that the decreasing number and survival of LGSOC over time may be due to a diagnosis-shift from LGSOC to serous-BOT. Given the distinct characteristics and outcomes of LGSOC compared to serous-BOT, our study endorses the importance of making the correct diagnosis upfront. Whether this diagnostic-shift supports a hypothesis that serous-BOT is a precursor lesion of LGSOC merits further investigation.

EMR 20006-012: A phase II randomized double-blind placebo controlled trial comparing the combination of pimasertib (MEK inhibitor) with SAR245409 (PI3K inhibitor) to pimasertib alone in patients with previously treated unresectable borderline or low grade ovarian cancer

OBJECTIVE

To compare the combination of a MEK inhibitor (pimasertib) and a PI3K inhibitor (SAR245409) to pimasertib alone in recurrent unresectable borderline/low malignant potential (LMP) or low-grade serous ovarian carcinoma (LGSOC), determining whether combination is superior.

METHODS

Patients with previously treated, recurrent LMP or LGSOC with measurable disease received either combination of pimasertib (60 mg daily) + SAR245409 (SAR) (70 mg daily) or pimasertib alone (60 mg BID) until progression or unacceptable toxicity. Primary endpoint was objective response rate (ORR) by RECIST 1.1, determining whether combination was superior to pimasertib alone. Secondary endpoints included progression free survival (PFS), disease control, and adverse events.

RESULTS

Sixty-five patients were randomized between September 2012 and December 2014. ORR was 9.4% (80% CI, 3.5 to 19.7) in the combination arm and 12.1% (80% CI, 5.4 to 22.8) in the pimasertib alone arm. Median PFS was 7.23 months (80% CI, 5.06 to -) and 9.99 (80% CI, 7.39 to 10.35) for pimasertib alone and pimasertib + SAR, respectively. Six-month PFS was 63.5% (80% CI, 47.2% to 75.9%) and 70.8% (80% CI, 56.9% to 80.9%). Eighteen (56.3%) patients in the combination arm and 19 (57.6%) patients in the pimasertib alone arm discontinued the trial. The study was terminated early because of low ORR and high rate of discontinuation.

CONCLUSIONS

Response to pimasertib alone (ORR 12%) suggests that MEK inhibition could be used as an alternative treatment method to cytotoxic chemotherapy in this population. The MEK inhibitor alone was as effective as the combination, although the trial was limited by small numbers. Additional studies investigating the role of single agent or combination MEK and PI3K inhibition are warranted to further evaluate the utility of these treatments and describe a standard of care for LGSOC.

Peritoneal involvement by salpingoliths clinical significance and cytological challenges of interpretation

We present a case of salpingoliths detected in peritoneal washing, during an elective bilateral salpingo-oophorectomy, in a 32 years old woman with history of familial BRCA gene mutation. Salpingoliths are psammoma body-like types of calcification that originate from the fallopian tubes and can be encountered in peritoneal washings. Unlike psammoma bodies, salpingoliths have been tagged to benign and hyperplastic processes more often than neoplastic processes. Misinterpreting salpingoliths as psammoma bodies in peritoneal washings can be misleading for both cytopathologists and clinicians, especially as in the presented case, where there is a high risk for ovarian carcinoma. In this article, we aim to shed light on this rare finding, and report theories explaining its pathogenesis, in addition we provide an example of its challenging cytological presentation, to increase awareness among cytopathologists.

Intrinsic Resistance to MEK Inhibition through BET Protein-Mediated Kinome Reprogramming in NF1-Deficient Ovarian Cancer

Mutation or deletion of Neurofibromin 1 (NF1), an inhibitor of RAS signaling, frequently occurs in epithelial ovarian cancer (EOC), supporting therapies that target downstream RAS effectors, such as the RAF-MEK-ERK pathway. However, no comprehensive studies have been carried out testing the efficacy of MEK inhibition in NF1-deficient EOC. Here, we performed a detailed characterization of MEK inhibition in NF1-deficient EOC cell lines using kinome profiling and RNA sequencing. Our studies showed MEK inhibitors (MEKi) were ineffective at providing durable growth inhibition in NF1-deficient cells due to kinome reprogramming. MEKi-mediated destabilization of FOSL1 resulted in induced expression of receptor tyrosine kinases (RTK) and their downstream RAF and PI3K signaling, thus overcoming MEKi therapy. MEKi synthetic enhancement screens identified BRD2 and BRD4 as integral mediators of the MEKi-induced RTK signatures. Inhibition of bromo and extra terminal (BET) proteins using BET bromodomain inhibitors blocked MEKi-induced RTK reprogramming, indicating that BRD2 and BRD4 represent promising therapeutic targets in combination with MEKi to block resistance due to kinome reprogramming in NF1-deficient EOC. IMPLICATIONS: Our findings suggest MEK inhibitors will likely not be effective as single-agent therapies in NF1-deficient EOC due to kinome reprogramming. Cotargeting BET proteins in combination with MEKis to block reprogramming at the transcriptional level may provide an epigenetic strategy to overcome MEKi resistance in NF1-deficient EOC.

An organoid platform for ovarian cancer captures intra- and interpatient heterogeneity

Ovarian cancer (OC) is a heterogeneous disease usually diagnosed at a late stage. Experimental in vitro models that faithfully capture the hallmarks and tumor heterogeneity of OC are limited and hard to establish. We present a protocol that enables efficient derivation and long-term expansion of OC organoids. Utilizing this protocol, we have established 56 organoid lines from 32 patients, representing all main subtypes of OC. OC organoids recapitulate histological and genomic features of the pertinent lesion from which they were derived, illustrating intra- and interpatient heterogeneity, and can be genetically modified. We show that OC organoids can be used for drug-screening assays and capture different tumor subtype responses to the gold standard platinum-based chemotherapy, including acquisition of chemoresistance in recurrent disease. Finally, OC organoids can be xenografted, enabling in vivo drug-sensitivity assays. Taken together, this demonstrates their potential application for research and personalized medicine.

Impact of somatic molecular profiling on clinical trial outcomes in rare epithelial gynecologic cancer patients

OBJECTIVES

Conducting clinical trials in rare malignancies is challenging due to the limited number of patients and differences in biologic behavior. We investigated the feasibility and clinical utility of using genomic profiling for rare gynecologic malignancies.

METHODS

Rare epithelial gynecologic cancer patients were analyzed for somatic variants through an institutional molecular profiling program using the Sequenom MassArray platform or the TruSeq Amplicon Cancer Panel on the MiSeq platform. Clinical trial outcomes by RECIST 1.1, and time on treatment were evaluated.

RESULTS

From March 2012 to November 2015, 767 gynecologic patients were enrolled and 194 (27%) were classified as rare epithelial malignancies. At least one somatic mutation was identified in 72% of patients, most commonly in TP53 (39%), KRAS (28%) and PIK3CA (27%). A total of 14% of patients were treated on genotype-matched trials. There were no significant differences in overall response rate between genotype-matched versus unmatched trials, nor in median time on treatment between genotype trials and the immediate prior systemic standard treatment. Among 13 evaluable Low Grade Serous ovarian cancer patients treated on genotype-matched trials with MEK inhibitor-based targeted combinations, there were four partial responses.

CONCLUSIONS

Somatic molecular profiling is feasible and enables the identification of patients with rare gynecologic cancers who are candidates for genotype-matched clinical trials. Genotype-matched trials, predominantly MEK-based combinations in KRAS and/or NRAS mutant Low Grade Serous ovarian cancer patients, and genotype-unmatched trials, have shown potential clinical activity. Prospective trials with integrated genotyping are warranted to assess the clinical utility of next generation sequencing tests as a standard clinical application in rare malignancies.

Low-grade epithelial ovarian cancer: what a radiologist should know

Ovarian cancer accounts for the death of over 100,000 females every year and is the most lethal gynecological malignancy. Low-grade serous ovarian carcinoma (LGSOC) and high-grade serous ovarian carcinoma (HGSOC) have been found to represent two distinct entities based on their molecular differences, clinical course, and response to chemotherapy. Currently, all ovarian cancers are staged according to the revised staging system of the International Federation of Gynecology and Obstetrics (FIGO). Imaging plays an integral role in the diagnosis, staging, and follow-up of ovarian cancers. This review will be based on the two-tier grading system of epithelial ovarian cancers, with the main emphasis on serous ovarian cancer, and the role of imaging to characterize low-grade vs high-grade tumors and monitor disease recurrence during follow-up.

The role of menopausal hormone therapy in women with or at risk of ovarian and breast cancers: Misconceptions and current directions

For women who are candidates for menopausal hormone therapy (MHT), estrogen can provide relief from symptomatic menopause, decrease rates of chronic illnesses, and improve health-related quality of life. However, confusion surrounds the evidence regarding the impact of exogenous estrogen and progesterone on the breast and ovary. Available data regarding the risks of MHT (estrogen and/or progestin) related to the development of breast and ovarian cancer are often inconsistent or incomplete. Modern molecular and genetic techniques have improved our understanding of the heterogeneity of breast and ovarian cancer. This enhanced understanding of the disease has impacted our understanding of carcinogenesis. Treatment options have evolved to be more targeted toward hormonal therapy for certain subtypes of disease, whereas cytotoxic chemotherapy remains the standard for other histological and molecular subtypes. The role of MHT in the breast and ovarian cancer survivor, as well as women who are at high risk for the development of hereditary breast and ovarian cancer, remains controversial despite evidence that this treatment can improve quality of life and survival outcomes. Through this article, we examine the evidence for and against the use of MHT with a focus on women who have or are at high risk for breast and ovarian cancer.

Efficacy of Pegylated Liposomal Doxorubicin in Low-Grade Serous Ovarian Carcinoma

OBJECTIVE

The aim of this study was to assess the efficacy of pegylated liposomal doxorubicin (PLD) in low-grade serous ovarian carcinoma (LGSOC).

METHODS

We retrospectively identified patients with LGSOC who were treated with PLD. Response to therapy was evaluated by RECIST 1.1 criteria. Progression-free survival (PFS) and overall survival were calculated. In addition, PFS on PLD was compared with the patient's most recent PFS on previous therapy.

RESULTS

Twenty-four patients were treated with PLD. Three patients were not evaluable, leaving 21 patients evaluable for response. Pegylated liposomal doxorubicin was dosed at 40 mg/M every 28 days except in 7 patients (5 received PLD dosed at 30 mg/M in combination with carboplatin and 2 received PLD dosed at 20 mg/M, one of which was in combination with etoposide). Four of the patients who received PLD in combination subsequently received PLD alone for 4+, 12, 21, and 29 cycles, respectively. Three patients (14.3%) had a complete response and remained progression free at 8, 31, and 34 months, respectively. Two of these patients received PLD alone. The third complete response patient initially received PLD in combination with carboplatin and then went on to receive PLD alone during which a complete radiologic response was achieved. No difference in response or PFS by platinum sensitivity was noted (Ps = 0.73 and 0.62, respectively). Fourteen patients had stable disease for a median of 18 months. Among the 14 patients with stable disease, the PFS on PLD exceeded the previous PFS in 11 patients (78.6%) from 1.3 to 20.6 folds, with a median of 3.5 folds. The 2 of the 3 lowest increases in PFSs were seen in patients whose therapy was terminated despite stable disease.

CONCLUSIONS

Pegylated liposomal doxorubicin is relatively active in LGSOC. The treatment of stable disease resulted in increase in PFS in 78.6% of patients by a mean of 350%.

Imaging in gynecological disease (12): clinical and ultrasound features of invasive and non-invasive malignant serous ovarian tumors

OBJECTIVES

To describe clinical and ultrasound features of different subclasses of malignant serous ovarian tumors according to the World Health Organization 2014 classification.

METHODS

Patients with a histological diagnosis of borderline tumor (BOT), non-invasive and invasive low-grade serous carcinoma (LGSC) and high-grade serous carcinoma (HGSC), who had undergone preoperative ultrasound examination, were retrospectively identified from two ultrasound centers. The masses were described using the terms of the International Ovarian Tumor Analysis Group.

RESULTS

Sixty-four (15.8%) women had a serous BOT, 11 (2.7%) a non-invasive LGSC, 31 (7.6%) an invasive LGSC and 300 (73.9%) had a HGSC. The vast majority of BOTs (82.3%) and non-invasive LGSCs (90.9%) were Stage I according to the International Federation of Gynecology and Obstetrics (FIGO) classification scheme, whereas most invasive LGSCs (74.2%) and HGSCs (74.0%) were FIGO Stage III. On ultrasound examination, most borderline lesions were described as unilocular-solid (54.7%) or as multilocular-solid (29.7%) cysts. Papillary projections were present in 52 (81.3%) BOTs. Most non-invasive LGSCs (63.6%) were multilocular-solid cysts and 81.8% had papillary projections. Invasive LGSCs were multilocular-solid cysts in 54.8% of cases, and papillary projections were present in 32.3% of lesions. HGSCs were multilocular-solid (32.7%) or solid (64.0%) masses, with papillary projections in only 7% of cases.

CONCLUSIONS

Papillary projections were the most typical ultrasound feature of non-invasive (borderline and low-grade) malignant serous tumors, while the presence of solid components but few, if any, papillations was the most representative feature of invasive (low-grade and high-grade) serous tumors. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Impact of lympho-vascular space invasion on tumor characteristics and survival outcome of women with low-grade serous ovarian carcinoma

BACKGROUND AND OBJECTIVES

To examine association of lympho-vascular space invasion (LVSI) with clinico-pathological factors and to evaluate survival of women with low-grade serous ovarian carcinoma containing areas of LVSI.

METHODS

This is a multicenter retrospective study examining consecutive cases of surgically treated stage I-IV low-grade serous ovarian carcinoma (n = 178). Archived histopathology slides for the ovarian tumors were reviewed, and LVSI was scored as present or absent. LVSI status was correlated to clinico-pathological findings and survival outcome.

RESULTS

LVSI was seen in 79 cases (44.4%, 95% confidence interval [CI] 37.1-51.7). LVSI was associated with increased risk of omental metastasis (87.0% vs 64.9%, odds ratio [OR] 3.62, P = 0.001), high pelvic lymph node ratio (median 12.9% vs 0%, P = 0.012), and malignant ascites (49.3% vs 32.6%, OR 2.01, P = 0.035). On multivariable analysis, controlling for age, stage, and cytoreductive status, presence of LVSI in the ovarian tumor remained an independent predictor for decreased progression-free survival (5-year rates 21.0% vs 35.7%, adjusted-hazard ratio 1.57, 95%CI 1.06-2.34, P = 0.026). LVSI was significantly associated with increased risk of recurrence in lymph nodes (OR 2.62, 95%CI 1.08-6.35, P = 0.047).

CONCLUSION

LVSI in the ovarian tumor is associated with adverse clinico-pathological characteristics and decreased progression-free survival in women with low-grade serous ovarian carcinoma.

EIF1AX and NRAS Mutations Co-occur and Cooperate in Low-Grade Serous Ovarian Carcinomas

Low-grade serous ovarian carcinomas (LGSC) are associated with a poor response to chemotherapy and are molecularly characterized by RAS pathway activation. Using exome and whole genome sequencing, we identified recurrent mutations in the protein translational regulator EIF1AX and in NF1, USP9X, KRAS, BRAF, and NRAS RAS pathway mutations were mutually exclusive; however, we found significant co-occurrence of mutations in NRAS and EIF1AX Missense EIF1AX mutations were clustered at the N-terminus of the protein in a region associated with its role in ensuring translational initiation fidelity. Coexpression of mutant NRAS and EIF1AX proteins promoted proliferation and clonogenic survival in LGSC cells, providing the first example of co-occurring, growth-promoting mutational events in ovarian cancer. Cancer Res; 77(16); 4268-78. ©2017 AACR.

Ovarian cancer: Novel molecular aspects for clinical assessment

Ovarian cancer is a very heterogeneous tumor which has been traditionally characterized according to the different histological subtypes and differentiation degree. In recent years, innovative molecular screening biotechnologies have allowed to identify further subtypes of this cancer based on gene expression profiles, mutational features, and epigenetic factors. These novel classification systems emphasizing the molecular signatures within the broad spectrum of ovarian cancer have not only allowed a more precise prognostic prediction, but also proper therapeutic strategies for specific subgroups of patients. The bulk of available scientific data and the high refinement of molecular classifications of ovarian cancers can today address the research towards innovative drugs with the adoption of targeted therapies tailored for single molecular profiles leading to a better prediction of therapeutic response. Here, we summarize the current state of knowledge on the molecular bases of ovarian cancer, from the description of its molecular subtypes derived from wide high-throughput analyses to the latest discoveries of the ovarian cancer stem cells. The latest personalized treatment options are also presented with recent advances in using PARP inhibitors, anti-angiogenic, anti-folate receptor and anti-cancer stem cells treatment approaches.

Outcomes of Women With High-Grade and Low-Grade Advanced-Stage Serous Epithelial Ovarian Cancer

OBJECTIVE

To compare outcomes of women with advanced-stage low-grade serous ovarian cancer and high-grade serous ovarian cancer and identify factors associated with survival among patients with advanced-stage low-grade serous ovarian cancer.

METHODS

A retrospective study of patients diagnosed with grade 1 or 3, advanced-stage (stage IIIC and IV) serous ovarian cancer between 2003 and 2011 was undertaken using the National Cancer Database, a large administrative database. The effect of grade on survival was analyzed using the Kaplan-Meier method. Factors predictive of outcome were compared using the Cox proportional hazards model. Among women with low-grade serous ovarian cancer, propensity score matching was used to compare all-cause mortality among similar women who underwent chemotherapy and lymph node dissection and those who did not.

RESULTS

A total of 16,854 (95.7%) patients with high-grade serous ovarian cancer and 755 (4.3%) patients with low-grade serous ovarian cancer were identified. Median overall survival was 40.7 months among high-grade patients and 90.8 months among women with low-grade tumors (P<.001). Among patients with low-grade serous ovarian cancer in the propensity score-matched cohort, the median overall survival was 88.2 months among the 140 patients who received chemotherapy and 95.9 months among the 140 who did not receive chemotherapy (P=.7). Conversely, in the lymph node dissection propensity-matched cohort, median overall survival was 106.5 months among the 202 patients who underwent lymph node dissection and 58 months among the 202 who did not (P<.001).

CONCLUSION

When compared with high-grade serous ovarian cancer, low-grade serous ovarian cancer is associated with improved survival. In patients with advanced-stage low-grade serous ovarian cancer, lymphadenectomy but not adjuvant chemotherapy was associated with improved survival.

Frequency of papillary tubal hyperplasia (PTH), salpingoliths and transition from adenoma to borderline ovarian tumors (BOT): A systematic analysis of 74 BOT with different histologic types

Borderline ovarian tumors (BOT) arise from cystadenomas and represent a transition step within the development of low-grade ovarian carcinomas (Type I tumors). That pathway mirrors the adenoma-to-carcinoma sequence known for colorectal cancer. It has been suggested that papillary tubal hyperplasia (PTH) and salpingoliths may be associated with the development of BOT. To evaluate the frequency of the presence of benign cystadenoma and its transition to BOT in a given patient as well as the presence of PTH and salpingoliths we re-valuated in 74 consecutive cases of BOT with different histologic types. The majority of cases represented serous-BOT (60.8%), followed by mucinous BOT (25.7%), other histologic types were rare. 86.5% showed an adenoma-BOT sequence, which was seen in all mucinous BOT but was missed in 15.6% of serous BOT. Two cases had salpingoliths without associated PTH. PTH was seen in four out of the 74 (5.4%) BOT and occurred only in cases with serous histology. The vast majority of BOT represent a transition from benign cystadenoma to BOT in cases with mucinous and serous histology. Salpingoliths are rarely seen in association with BOT and occurred exclusively in BOT with serous histology. PTH may represent a distinct lesion but is rarely seen in association with BOT, especially in those with non-serous histology. Further studies are needed to evaluate the frequency and pathogenetic association of PTH with BOT.

Low-grade serous ovarian cancer: A review

Epithelial ovarian cancers can be divided into the more common, aggressive type II cancers and the less common, slow-growing type I cancers. Under this model, serous ovarian carcinomas can be subdivided into high-grade (type II) and low-grade (type I) tumours. The two-tier system for grading serous ovarian carcinomas is superior to more detailed grading systems in terms of predicting survival. Low-grade serous carcinomas typically present in young women and have a relatively good prognosis, despite being resistant to chemotherapy. Low-grade serous cancers have a high prevalence of KRAS and BRAF mutations, but a low prevalence of TP53 mutations (which are characteristic of high-grade serous cancers). Among women with low-grade serous ovarian cancer, the presence of a KRAS/BRAF mutation is a favorable prognostic factor. Studies of the mitogen-activated protein kinase (MAPK) inhibitor in low-grade serous ovarian cancer suggest that identifying MAPK mutations might eventually be useful in guiding treatment.

Ovarian cancer

Ovarian cancer is not a single disease and can be subdivided into at least five different histological subtypes that have different identifiable risk factors, cells of origin, molecular compositions, clinical features and treatments. Ovarian cancer is a global problem, is typically diagnosed at a late stage and has no effective screening strategy. Standard treatments for newly diagnosed cancer consist of cytoreductive surgery and platinum-based chemotherapy. In recurrent cancer, chemotherapy, anti-angiogenic agents and poly(ADP-ribose) polymerase inhibitors are used, and immunological therapies are currently being tested. High-grade serous carcinoma (HGSC) is the most commonly diagnosed form of ovarian cancer and at diagnosis is typically very responsive to platinum-based chemotherapy. However, in addition to the other histologies, HGSCs frequently relapse and become increasingly resistant to chemotherapy. Consequently, understanding the mechanisms underlying platinum resistance and finding ways to overcome them are active areas of study in ovarian cancer. Substantial progress has been made in identifying genes that are associated with a high risk of ovarian cancer (such as BRCA1 and BRCA2), as well as a precursor lesion of HGSC called serous tubal intraepithelial carcinoma, which holds promise for identifying individuals at high risk of developing the disease and for developing prevention strategies.

Ovarian cancer

Ovarian cancer is not a single disease and can be subdivided into at least five different histological subtypes that have different identifiable risk factors, cells of origin, molecular compositions, clinical features and treatments. Ovarian cancer is a global problem, is typically diagnosed at a late stage and has no effective screening strategy. Standard treatments for newly diagnosed cancer consist of cytoreductive surgery and platinum-based chemotherapy. In recurrent cancer, chemotherapy, anti-angiogenic agents and poly(ADP-ribose) polymerase inhibitors are used, and immunological therapies are currently being tested. High-grade serous carcinoma (HGSC) is the most commonly diagnosed form of ovarian cancer and at diagnosis is typically very responsive to platinum-based chemotherapy. However, in addition to the other histologies, HGSCs frequently relapse and become increasingly resistant to chemotherapy. Consequently, understanding the mechanisms underlying platinum resistance and finding ways to overcome them are active areas of study in ovarian cancer. Substantial progress has been made in identifying genes that are associated with a high risk of ovarian cancer (such as BRCA1 and BRCA2), as well as a precursor lesion of HGSC called serous tubal intraepithelial carcinoma, which holds promise for identifying individuals at high risk of developing the disease and for developing prevention strategies.

Ovarian cancer

Ovarian cancer is not a single disease and can be subdivided into at least five different histological subtypes that have different identifiable risk factors, cells of origin, molecular compositions, clinical features and treatments. Ovarian cancer is a global problem, is typically diagnosed at a late stage and has no effective screening strategy. Standard treatments for newly diagnosed cancer consist of cytoreductive surgery and platinum-based chemotherapy. In recurrent cancer, chemotherapy, anti-angiogenic agents and poly(ADP-ribose) polymerase inhibitors are used, and immunological therapies are currently being tested. High-grade serous carcinoma (HGSC) is the most commonly diagnosed form of ovarian cancer and at diagnosis is typically very responsive to platinum-based chemotherapy. However, in addition to the other histologies, HGSCs frequently relapse and become increasingly resistant to chemotherapy. Consequently, understanding the mechanisms underlying platinum resistance and finding ways to overcome them are active areas of study in ovarian cancer. Substantial progress has been made in identifying genes that are associated with a high risk of ovarian cancer (such as BRCA1 and BRCA2), as well as a precursor lesion of HGSC called serous tubal intraepithelial carcinoma, which holds promise for identifying individuals at high risk of developing the disease and for developing prevention strategies.

Increase in post-therapy tumor calcification on CT scan is not an indicator of response to therapy in low-grade serous ovarian cancer

PURPOSE

The aim of the study was to determine if increasing post-therapy calcification in peritoneal metastases in recurrent low-grade serous ovarian carcinomas indicated response to therapy.

MATERIALS AND METHODS

Retrospective analysis of patients with histologically confirmed, recurrent low-grade serous ovarian carcinoma who received treatment at our institution between 2000 and 2014 was performed. Only patients who had calcified tumor implants and showed either interval increase or decrease in tumor calcification following therapy were included in the study. Pre- and post-therapy CT scans of these patients were reviewed by 2 radiologists independently. Changes in the tumor calcification status and tumor deposits size were correlated with serum CA-125 levels. Fisher's exact test was used to assess the association between peritoneal deposit and calcification status with serum CA-125 status.

RESULTS

35 Patients were included in the study. Based on serial serum CA 125 levels, 22 patients (63%) had progressive disease, 12 (34%) had partial response and 1 (3%) had stable disease. Using RECIST 1.1, 16 had progressive disease, 3 had partial response and 16 had stable disease. In the patients with progressive disease, post-therapy tumor calcification increased in 77% and decreased in 23%. Fischer's exact test showed that serum CA 125 change was significantly associated with change in size of peritoneal deposits and calcification change.

CONCLUSIONS

This preliminary study shows that post-therapy increase in peritoneal implant calcification in low-grade serous ovarian carcinomas is not an indicator of response to therapy.

Operability and chemotherapy responsiveness in advanced low-grade serous ovarian cancer. An analysis of the AGO Study Group metadatabase

OBJECTIVE

Since almost two decades standard 1st-line chemotherapy for advanced ovarian cancer (AOC) has been a platinum/taxane combination. More recently, this general strategy has been challenged because different types of AOC may not benefit homogenously. Low-grade serous ovarian cancer (LGSOC) is one of the candidates in whom efficacy of standard chemotherapy should be revised.

METHODS

This study is an exploratory case control study of the AGO-metadatabase of 4 randomized phase III trials with first-line platinum combination chemotherapy without any targeted therapy. Patients with advanced FIGO IIIBIV low-grade serous ovarian cancer were included and compared with control cases having high-grade serous AOC.

RESULTS

Out of 5114 patients in this AGO database 145 (2.8%) had LGSOC and of those thirty-nine (24.1%) had suboptimal debulking with post-operative residual tumor >1cm, thus being eligible for response evaluation. An objective response was observed in only 10 patients and this 23.1% response rate (RR) was significantly lower compared to 90.1% RR in the control cohort of high-grade serous ovarian cancer (HGSOC) (p<0.001). Both, LGSOC and HGSOC patients who underwent complete cytoreduction had significantly better progression free survival (PFS) and overall survival (OS) in comparison to those with residuals after primary surgery, accordingly (p<0.001).

CONCLUSIONS

Our observation indicates that low-grade serous cancer is not as responsive to platinum-taxane-based chemotherapy as high-grade serous AOC. In contrast, surgical debulking showed a similar impact on outcome in both types of AOC thus indicating different roles for both standard treatment modalities. Systemic treatment of low grade serous AOC urgently warrants further investigations.

Paradigm Shift in the Management Strategy for Epithelial Ovarian Cancer

The hypothesis on the pathogenesis of epithelial ovarian cancer continues to evolve. Although epithelial ovarian cancer had been assumed to arise from the coelomic epithelium of the ovarian surface, it is now becoming clearer that the majority of serous carcinomas arise from epithelium of the distal fallopian tube, whereas clear cell and endometrioid cancers arise from endometriosis. Molecular and genomic characteristics of epithelial ovarian cancer have been extensively investigated. Our understanding of pathogenesis of the various histologic types of ovarian cancer have begun to inform changes to the strategies for management of epithelial ovarian cancer, which represent a paradigm shift not only for treatment but also for prevention, which previously had not been considered achievable. In this article, we will discuss novel attempts at the prevention of high-grade serous ovarian cancer and treatment strategies for two distinct entities in epithelial ovarian cancer: low-grade serous and clear cell ovarian carcinomas, which are relatively rare and resistant to conventional chemotherapy.

Pathobiology of ovarian carcinomas

Ovarian tumors comprise a heterogeneous group of lesions, displaying distinct tumor pathology and oncogenic potentiel. These tumors are subdivided into three main categories: epithelial, germ cell, and sex-cord stromal tumors. We report herein the newly described molecular abnormalities in epithelial ovarian cancers (carcinomas). Immunohistochemistry and molecular testing help pathologists to decipher the significant heterogeneity of this disease. Our better understanding of the molecular basis of ovarian carcinomas represents the first step in the development of targeted therapies in the near future.

Obesity is associated with worse overall survival in women with low-grade papillary serous epithelial ovarian cancer

OBJECTIVE

The objective of this study was to evaluate prognostic risk factors for survival in women with low-grade serous epithelial ovarian cancer (LGSC).

METHODS

A multicenter retrospective analysis of patients with LGSC was conducted. Potential epidemiologic risk factors evaluated included obesity, age, parity, race, smoking, oral contraceptive pill and/or hormonal replacement therapy use, and previous hysterectomy or surgery on fallopian tubes and/or ovaries. Additional factors included stage, extent of debulking, residual disease, and disease status.

RESULTS

Eighty-one patients were identified, and pathologic diagnosis was independently confirmed. Median age at diagnosis was 56 years (range, 21-86 years). Thirty-four percent were obese, and 80% had optimally debulked disease. Forty-six percent were alive, 14% with disease, whereas 25% were dead of disease, 2% died of intercurrent disease, and 27% had an unknown status. In a univariate analysis, optimal surgical debulking was associated with improved progression-free survival (P = 0.01), disease-specific survival (P = 0.03), and overall survival (OS) (P < 0.001) and body mass index with worse OS (P = 0.05). On multivariate analysis, obesity (hazard ratio, 2.8; 95% confidence interval, 1.05-7.3; P = 0.04) and optimal tumor debulking (hazard ratio, 0.05; 95% confidence interval, 0.008-0.29; P = 0.001) were a significant predictor of OS.

CONCLUSIONS

In a multivariate analysis, obesity and optimal tumor cytoreduction were significant predictors of OS. However, obesity was not associated with worse disease-specific survival, suggesting that mortality of obese patients with LGSC may result from other comorbidities. Interventions addressing obesity may improve survival for women diagnosed with LGSC, and further study is warranted to address the role of obesity in LGSC.

CT features of low grade serous carcinoma of the ovary

Objective

To evaluate the CT features of pathologically proven low grade serous carcinoma (LGSC) of the ovary.

Methods

Patients with a pathologic diagnosis of LGSC and CT prior to oophorectomy were retrospectively identified. The CT scans in 14 patients were available and were analyzed for an adnexal mass, peritoneal mass and ascites. The adnexal mass was characterized as complex primarily cystic, mixed cystic solid, or primarily solid. Calcification in the adnexal and peritoneal masses and nodes was noted.

Results

Pathology revealed 6 patients had LGSC and 8 patients had a combined diagnosis of LGSC and serous borderline tumor (SBT) of the ovary. Of the 6 patients with only LGSC, 4 had primarily solid or mixed solid cystic adnexal masses and 5 had peritoneal masses. Calcification was present in the adnexal and peritoneal masses in 4 patients, and in nodes in 2 patients. Of the 8 patients with co-existing LGSC and SBT, 7 had complex primarily cystic adnexal masses and 6 had peritoneal masses. Calcification was present in the adnexal and peritoneal masses in 5 patients and in nodes in 2 patients.

Conclusion

LGSC can appear as a solid, mixed solid cystic, or complex primarily cystic ovarian mass, and the appearance may be due to a co-existing SBT. Calcification of the adnexal and peritoneal masses appears to be common. LGSC is a diagnostic consideration in patients with a calcified adnexal mass and concurrent peritoneal masses or calcified nodes on CT.

Trabectedin therapy as an emerging treatment strategy for recurrent platinum-sensitive ovarian cancer

Epithelial ovarian cancer (OC) is a common gynecologic malignancy in women. The standard treatment for OC is maximal cytoreductive surgical debulking followed by platinum-based chemotherapy. Despite the high response rate to primary therapy, approximately 85% of patients will develop recurrent ovarian cancer (ROC). This review identifies the clinical use of trabectedin in the treatment algorithm for ROC, with specific emphasis on platinum-sensitive ROC, for which trabectedin in combination with pegylated liposomal doxorubicin has been approved as a treatment protocol. The main mechanisms of action of trabectedin at the cellular level and in the tumor microenvironment is also discussed as bases for identifying biomarkers for selecting patients who may largely benefit from trabectedin-based therapies.

Intratumoral heterogeneity in a minority of ovarian low-grade serous carcinomas

Background

Ovarian low-grade serous carcinoma (LGSC) has fewer mutations than ovarian high-grade serous carcinoma (HGSC) and a less aggressive clinical course. However, an overwhelming majority of LGSC patients do not respond to conventional chemotherapy resulting in a poor long-term prognosis comparable to women diagnosed with HGSC. KRAS and BRAF mutations are common in LGSC, leading to clinical trials targeting the MAPK pathway. We assessed the stability of targetable somatic mutations over space and/or time in LGSC, with a view to inform stratified treatment strategies and clinical trial design.

Methods

Eleven LGSC cases with primary and recurrent paired samples were identified (stage IIB-IV). Tumor DNA was isolated from 1–4 formalin-fixed paraffin-embedded tumor blocks from both the primary and recurrence (n = 37 tumor and n = 7 normal samples). Mutational analysis was performed using the Ion Torrent AmpliSeq^TM Cancer Panel, with targeted validation using Fluidigm-MiSeq, Sanger sequencing and/or Raindance Raindrop digital PCR.

Results

KRAS (3/11), BRAF (2/11) and/or NRAS (1/11) mutations were identified in five unique cases. A novel, non-synonymous mutation in SMAD4 was observed in one case. No somatic mutations were detected in the remaining six cases. In two cases with a single matched primary and recurrent sample, two KRAS hotspot mutations (G12V, G12R) were both stable over time. In three cases with multiple samplings from both the primary and recurrent surgery some mutations (NRAS Q61R, BRAF V600E, SMAD4 R361G) were stable across all samples, while others (KRAS G12V, BRAF G469V) were unstable.

Conclusions

Overall, the majority of cases with detectable somatic mutations showed mutational stability over space and time while one of five cases showed both temporal and spatial mutational instability in presumed drivers of disease. Investigation of additional cases is required to confirm whether mutational heterogeneity in a minority of LGSC is a general phenomenon that should be factored into the design of clinical trials and stratified treatment for this patient population.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2407-14-982) contains supplementary material, which is available to authorized users.

Absence of DICER1, CTCF, RPL22, DNMT3A, TRRAP, IDH1 and IDH2 hotspot mutations in patients with various subtypes of ovarian carcinomas

Cancer is caused by multiple genetic alterations within cells. Recently, large-scale sequencing has identified frequent ribonuclease type III (DICER1), CCCTC-binding factor (CTCF), ribosomal protein L22 (RPL22), DNA (cytosine-5-)-methyltransferase 3α (DNMT3A), transformation/transcription domain-associated protein (TRRAP), isocitrate dehydrogenase (IDH)1 and IDH2 hotspot mutations in diverse types of cancer. However, it remains largely unknown whether these mutations also exist in ovarian carcinomas. In the present study, a collection of 251 patients with distinct subtypes of ovarian carcinomas were recruited and sequenced for the presence of these hotspot mutations. However, no mutations in the seven genes were detected in the samples. These negative results, together with certain recent reports, indicate that the hotspot mutations in the CTCF, RPL22, DNMT3A, TRRAP, IDH1 and IDH2 genes may not be actively involved in the carcinogenesis of ovarian carcinoma. Of note, the DICER1 mutation frequency in Sertoli-Leydig cell tumor in the present study was significantly lower compared to prior observation, and therefore, it is speculated that this discrepancy may be mainly due to the small sample size analyzed in the study. In addition, among these samples, frequent polymerase (DNA directed) ε, catalytic subunit (POLE1) and ring finger protein 43 (RNF43) mutations were identified in endometrioid and mucinous ovarian carcinomas, respectively; thus DICER1, CTCF, RPL22, DNMT3A, TRRAP, IDH1 and IDH2 hotspot mutations may not play synergistic roles with POLE1 or RNF43 mutations in the carcinogenesis of endometrioid or mucinous ovarian carcinomas.

A survival analysis comparing women with ovarian low-grade serous carcinoma to those with high-grade histology

Ovarian low-grade serous carcinoma (LGSC) and high-grade serous carcinoma have distinct molecular profiles, clinical behaviors, and treatment responses. The survival advantage for patients with low-grade carcinoma compared with patients with high-grade histology remains controversial. We retrospectively reviewed the medical charts of 381 patients with ovarian serous carcinoma at Peking Union Medical College Hospital from 2007 to 2010. Patients were classified into two groups according to MD Anderson two-tier system: 35 (9.2%) cases with LGSC and 346 with high-grade serous carcinoma. Patients with low-grade serous ovarian cancer had a significantly younger age at diagnosis (46 versus 56 years, P=0.046), and their median progression-free survival (PFS) and overall survival values were 35.0 and 54.0 months, respectively. A multivariate analysis showed that, for serous ovarian cancer, the histological grade was a significant prognostic factor for PFS but not for overall survival (P=0.022 and P=0.0566, respectively). When stratified by the existence of a residual disease, patients with low-grade disease who underwent cytoreductive surgery without macroscopic residual disease (>1 cm) had a significantly improved median PFS time (36.0 months) compared with that of patients with high-grade carcinoma who received optimal cytoreductive surgery (16.0 months, P=0.017). Conversely, patients with low-grade and high-grade carcinoma who were left with macroscopic residue (>1 cm) experienced a similarly shorter median PFS (10.0 and 13.0 months, respectively, P=0.871). The International Federation of Gynecology and Obstetrics stage and residual disease were significant prognostic factors of low-grade carcinoma, while positive ascites was associated with a worse PFS value. Our data showed that LGSC is a different entity from high-grade carcinoma and that LGSC was associated with improved PFS after optimal cytoreductive surgery but not suboptimal operation.

Genomic classification of serous ovarian cancer with adjacent borderline differentiates RAS pathway and TP53-mutant tumors and identifies NRAS as an oncogenic driver

PURPOSE

Low-grade serous ovarian carcinomas (LGSC) are Ras pathway-mutated, TP53 wild-type, and frequently associated with borderline tumors. Patients with LGSCs respond poorly to platinum-based chemotherapy and may benefit from pathway-targeted agents. High-grade serous carcinomas (HGSC) are TP53-mutated and are thought to be rarely associated with borderline tumors. We sought to determine whether borderline histology associated with grade 2 or 3 carcinoma was an indicator of Ras mutation, and we explored the molecular relationship between coexisting invasive and borderline histologies.

EXPERIMENTAL DESIGN

We reviewed >1,200 patients and identified 102 serous carcinomas with adjacent borderline regions for analyses, including candidate mutation screening, copy number, and gene expression profiling.

RESULTS

We found a similar frequency of low, moderate, and high-grade carcinomas with coexisting borderline histology. BRAF/KRAS alterations were common in LGSC; however, we also found recurrent NRAS mutations. Whereas borderline tumors harbored BRAF/KRAS mutations, NRAS mutations were restricted to carcinomas, representing the first example of a Ras oncogene with an obligatory association with invasive serous cancer. Coexisting borderline and invasive components showed nearly identical genomic profiles. Grade 2 cases with coexisting borderline included tumors with molecular features of LGSC, whereas others were typical of HGSC. However, all grade 3 carcinomas with coexisting borderline histology were molecularly indistinguishable from typical HGSC.

CONCLUSION

Our findings suggest that NRAS is an oncogenic driver in serous ovarian tumors. We demonstrate that borderline histology is an unreliable predictor of Ras pathway aberration and underscore an important role for molecular classification in identifying patients that may benefit from targeted agents.

Development and internal validation of a prognostic model for survival after debulking surgery for epithelial ovarian cancer

OBJECTIVE

Predicting survival of patients with epithelial ovarian cancer (EOC) is based on prognosis of the population. Combining prognostic factors could facilitate survival prediction on the level of the individual patient. The aim of this study was to develop a prognostic model to predict five-year disease specific survival in patients with EOC, and to evaluate whether this would add to prediction based on prognosis of the population.

PATIENTS AND METHODS

A retrospective cohort study was performed of all EOC patients treated with primary debulking and adjuvant chemotherapy or neo-adjuvant chemotherapy and interval debulking surgery in three gynaecological-oncologic centres between 1998 and 2010. Primary outcome was 5-year disease-specific survival. We developed a Cox proportional hazard model using the LASSO-method to select the best combination of characteristics from 12 potential predictors and to correct for overfitting. Performance of the model was expressed as calibration and discrimination (c-statistic). A nomogram was developed to increase the clinical applicability of the model.

RESULTS

Of 840 patients with EOC 462 (55%) died within 5 years due to the disease. A combination of FIGO stage, residual tumour after surgery, primary or interval surgery, histology, performance status, age, amount of ascites and a family history suggestive of breast/ovarian cancer best predicted 5-year survival. The final model showed accurate calibration and the c-statistic was 0.71 (95% CI 0.69-0.74).

CONCLUSIONS

Five-year survival in all stage EOC patients can be predicted accurately using available characteristics. After external validation the model can be used for counselling of patients.

Targeted therapies and clinical trials in ovarian cancer

Recent advances in molecular profiling have shown that cancers arising from the ovary are phenotypically and genetically heterogeneous. Within histologies, many mutations in druggable targets are uncommon in frequency but mutations leading to activation of specific signal transduction pathways are common. These results support the notion that different targeted agents should be prioritized for testing between and within ovarian cancer histologies. The subsegmentation of ovarian cancers based on molecular features challenge traditional trial designs. Feasibility of accrual and need for data on biological and clinical consequence or target inhibition are leading to trial designs that lump or split patient populations by histology, pathway, gene, and/or mutation. This review summarizes potential therapeutic targets identified from recent molecular profiling studies of ovarian cancers and trial designs to evaluate targeted agents in rare cancer settings.