Epidemiology of low-grade serous ovarian cancer

Germline testing of Iranian families suspected of Lynch syndrome: molecular characterization and current surveillance of families with pathogenic variants in MSH2, MSH6, and PMS2

Lynch syndrome accounts for 3-5% of all colorectal and endometrial cancer cases, and suboptimal management of Lynch syndrome in the Middle East resulted in the underdiagnosis of mutation carriers. Probands from 24 unrelated Iranian families with a history of cancer(s) suggestive of Lynch syndrome underwent microsatellite instability analysis or immunohistochemistry, multigene panel testing, copy number variation detection, or multiplex ligation-dependent probe amplification. Pathogenic variants were identified in five patients (21%), including three in MSH2, one in MSH6, and one in PMS2. Microsatellite instability analysis showed the lengths of the CAT25 marker in tumor and normal samples were 149 and 148 bp, respectively. Among 21 family members with Lynch syndrome in the MSH2 gene, identified from the three families who previously underwent cascade screening, colorectal and endometrial cancers were the most frequent. While 66% of patients had insurance that included coverage for mutation carrier screening, only one insurance provider extended coverage for next-generation sequencing. Special attention to probands and telematic management of at-risk relatives to organize blood sample collection at their convenience enhanced cascade testing 20-fold per proband. In conclusion, the age of onset and segregation analysis indicated that PMS1 may not be a cancer susceptibility gene, and the tumor spectrum in MSH2 pathogenic carriers is similar to Western countries. Collecting blood samples at patients' convenience is a possible strategy to reduce the cost of identifying Lynch syndrome through cascade testing. The genetic analysis of patients for inherited cancers would optimize the current management of Lynch syndrome in Iran by omitting noncarriers from surveillance programs.

Changes in the tumour microenvironment mark the transition from serous borderline tumour to low-grade serous carcinoma

Low-grade serous ovarian carcinoma (LGSC) is a rare and lethal subtype of ovarian cancer. LGSC is pathologically, biologically, and clinically distinct from the more common high-grade serous ovarian carcinoma (HGSC). LGSC arises from serous borderline ovarian tumours (SBTs). The mechanism of transformation for SBTs to LGSC remains poorly understood. To better understand the biology of LGSC, we performed whole proteome profiling of formalin-fixed, paraffin-embedded tissue blocks of LGSC (n = 11), HGSC (n = 19), and SBTs (n = 26). We identified that the whole proteome is able to distinguish between histotypes of the ovarian epithelial tumours. Proteins associated with the tumour microenvironment were differentially expressed between LGSC and SBTs. Fibroblast activation protein (FAP), a protein expressed in cancer-associated fibroblasts, is the most differentially abundant protein in LGSC compared with SBT. Multiplex immunohistochemistry (IHC) for immune markers (CD20, CD79a, CD3, CD8, and CD68) was performed to determine the presence of B cells, T cells, and macrophages. The LGSC FAP+ stroma was associated with greater abundance of Tregs and M2 macrophages, features not present in SBTs. Our proteomics cohort reveals that there are changes in the tumour microenvironment in LGSC compared with its putative precursor lesion, SBT. These changes suggest that the tumour microenvironment provides a supportive environment for LGSC tumourigenesis and progression. Thus, targeting the tumour microenvironment of LGSC may be a viable therapeutic strategy. © 2024 The Pathological Society of Great Britain and Ireland.

Novel Targeted Agents in Advanced and Recurrent Low-Grade Serous Ovarian Cancer: A Silver Lining in the Therapy of a Chemoresistant Disease?

Low-grade serous ovarian carcinoma (LGSOC) is a rare subtype of epithelial ovarian cancer, characterized by a unique molecular background and specific clinical behavior. A growing body of molecular data underscores LGSOC as a distinct disease entity; however, clinical evidence on the optimal treatment regimens for LGSOC remains limited due to the low incidence of the disease. Consequently, treatment recommendations for LGSOC are still often derived from findings on the more common high-grade serous ovarian carcinoma (HGSOC) and typically focus on radical cytoreductive surgery and platinum-based chemotherapy. Since LGSOCs typically exhibit only limited responsiveness to platinum-based chemotherapy, the clinical management of advanced and recurrent LGSOCs remains a significant therapeutic challenge and often results in limited treatment options and suboptimal outcomes. Recent advances in molecular profiling and the identification of new, promising targets, such as the mitogen-activated protein kinase (MAPK) pathway, offer hope for improving both the prognosis and health-related quality of life in affected patients. Given the high unmet clinical need to establish new therapeutic standards beyond cytotoxic chemotherapy, this review aims to summarize the most promising molecular targets and emerging targeted agents.

Targeted Therapies in Low-Grade Serous Ovarian Cancers

OPINION STATEMENT

Low grade serous carcinoma of the ovary has been delineated as a separate entity from its counterpart high grade serous carcinoma of the ovary. Molecular profiling has helped to further characterize this disease process and has led to new and exciting treatment options. Surgery has always been a cornerstone of management both in primary and recurrent disease settings. Chemotherapy has been a long-standing backbone of adjuvant treatment, but its efficacy continues to be questioned. Hormonal therapy for upfront and recurrent disease is an effective treatment option with a high response rate and minimal side effects. Newer therapies including MEK, CDK 4/6, and PI3KCA inhibitors have emerged as exciting options for recurrent disease. Ongoing clinical trials will hopefully lead to additional therapeutic opportunities based on novel biomarkers in this disease.

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.

Retrospective analysis of uterine involvement in low grade serous ovarian carcinoma

OBJECTIVES

Low grade serous ovarian carcinoma (LGSOC) accounts for 2.5% of all ovarian carcinoma more affects younger women than high grade serous ovarian carcinoma. Hysterectomy is performed routinely for LGSOC treatment, but fertility sparring surgery (FSS) is feasible for some early stages. Currently, there is no study about uterine involvement in LGSOC. We evaluate uterine involvement in LGSOC patients and aim to identify pre-operative predictive factors.

METHODS

Retrospective observational study of LGSOC patients treated between January 2000 and May 2022 in the Hospices Civils de Lyon. All cases were viewed, reviewed or approved by an expert pathologist.

RESULTS

Among 535 serous ovarian carcinomas, 26 were included. Most patients (73 %) had FIGO III disease. Median OS was 115 months and median PFS was 42 months. Uterine involvement was found in 58 % patients who underwent hysterectomy (14/24), serosal involvement was the most frequent type of involvement (n = 13, 54 %). Myometrial involvement was found in 8 patients (33 %) and was associated with serosal involvement (7/8). Among patients with a macroscopic disease-free uterus during exploratory laparoscopy, 31 % had a microscopic serosal involvement. None patient with presumed early stage (FIGO I) were upstaged due to uterine involvement (serosal or myometrial). In patients with stage FIGO IIII, 72 % of uterine involvement were found. Univariate analysis did not show any predictive factor of myometrial involvement. There was no difference on OS nor PFS between patients with or without myometrial involvement.

CONCLUSIONS

In early stages LGSOC, FSS may be considered for selected patients. In advanced stages, hysterectomy should be performed routinely, since no predictive factor for uterine involvement were identified.

Low-grade versus high-grade serous ovarian cancer: comparison of surgical outcomes after secondary cytoreductive surgery

OBJECTIVE

Retrospective series have shown secondary cytoreductive surgery improves oncological outcomes in recurrent low-grade serous ovarian cancer. We aim to compare surgical procedures and complications between patients with low-grade and high-grade recurrent serous ovarian cancer.

METHODS

This retrospective single-institution study includes patients with recurrent low-grade and high-grade serous ovarian cancer undergoing surgery between January 2012 to December 2021. Patients were propensity matched 1:3 for residual tumor at first surgery, presence of ascites and performance status. Complexity of surgery and postoperative complications were analyzed.

RESULTS

A total of 116 patients undergoing secondary cytoreductive surgery were included with 29 patients (25%) having low-grade ovarian cancer. The median age of the patients was 54 years (range: 19-85) and 57 years (range: 29-78) in low-grade and high-grade ovarian cancer, respectively (p=0.13). Stages III/IV at diagnosis were more frequent in patients with high-grade ovarian cancers (p<0.001). Peritoneal involvement was higher in low-grade compared with high-grade ovarian cancer as shown by the higher rate of diaphragmatic (41.4% vs 21.8%, p=0.05), abdominal wall (41.4% vs 18.4%, p=0.02) and pelvic (51.7% vs 21.8%, p=0.01) peritonectomy. Multiple bowel resections were higher in low-grade ovarian cancer (24.1% vs 8.0%, p=0.04), while high-grade ovarian cancer had a higher rate of nodal recurrences (73.2%% vs 37.9%, p=0.03). Overall, surgical complexity was higher in low-grade ovarian cancer (58.6% vs 36.8%; p=0.05), with higher median estimated blood loss (400 vs 200 mL; p=0.01) compared with high-grade. Complete cytoreduction was achieved in 26 patients (89.7%) with low-grade and 84 (96.6%) with high-grade (p=0.16) ovarian cancer, with no significant differences in postoperative complications.

CONCLUSIONS

Secondary cytoreductive surgery in low-grade serous ovarian cancer patients was associated with higher complexity, multiple bowel resections, and higher median estimated blood loss than in high-grade serous ovarian cancer. The comparable rate of postoperative complications suggests that secondary cytoreductive surgery in this group of patients is feasible in expert centers.

Molecular Results and Potential Biomarkers Identified from the Phase 3 MILO/ENGOT-ov11 Study of Binimetinib versus Physician Choice of Chemotherapy in Recurrent Low-Grade Serous Ovarian Cancer

PURPOSE

We present the results of a post hoc tumor tissue analysis from the phase 3 MILO/ENGOT-ov11 study (NCT01849874).

PATIENTS AND METHODS

Mutation/copy-number analysis was performed on tissue obtained pre-randomization. The Kaplan-Meier method was used to estimate progression-free survival (PFS). Unbiased univariate analysis, Cox regression, and binary logistic regression were used to test associations between mutation status and outcomes, including PFS and binary response by local RECIST 1.1.

RESULTS

MILO/ENGOT-ov11 enrolled 341 patients, ranging in age from 22 to 79, from June, 2013 to April, 2016. Patients were randomized 2:1 to binimetinib or physician's choice of chemotherapy (PCC). The most commonly altered gene was KRAS (33%). In 135 patients treated with binimetinib with response rate (RR) data, other detected MAPK pathway alterations included: NRAS (n = 11, 8.1%), BRAF V600E (n = 8, 5.9%), RAF1 (n = 2, 1.5%), and NF1 (n = 7, 5.2%). In those with and without MAPK pathway alterations, the RRs with binimetinib were 41% and 13%, respectively. PFS was significantly longer in patients with, compared with those without, MAPK pathway alterations treated with binimetinib [HR, 0.5; 95% confidence interval (CI) 0.31-0.79]. There was a nonsignificant trend toward PFS improvement in PCC-treated patients with MAPK pathway alterations compared with those without (HR, 0.82; 95% CI, 0.43-1.59).

CONCLUSIONS

Although this hypothesis-generating analysis is limited by multiple testing, higher RRs and longer PFS were seen in patients with low-grade serous ovarian cancer (LGSOC) treated with binimetinib, and to a lesser extent in those treated with PCC, who harbored MAPK pathway alterations. Somatic tumor testing should be routinely considered in patients with LGSOC and used as a future stratification factor.

Low-grade serous ovarian cancer: expert consensus report on the state of the science

Compared with high-grade serous carcinoma, low-grade serous carcinoma of the ovary or peritoneum is a less frequent epithelial ovarian cancer type that is poorly sensitive to chemotherapy and affects younger women, many of whom endure years of ineffective treatments and poor quality of life. The pathogenesis of this disease and its management remain incompletely understood. However, recent advances in the molecular characterization of the disease and identification of novel targeted therapies with activity in low-grade serous carcinoma offer the promise of improved outcomes. To update clinicians regarding recent scientific and clinical trial advancements and discuss unanswered questions related to low-grade serous carcinoma diagnosis and treatment, a panel of experts convened for a workshop in October 2022 to develop a consensus document addressing pathology, translational research, epidemiology and risk, clinical management, and ongoing research. In addition, the patient perspective was discussed. The recommendations developed by this expert panel-presented in this consensus document-will guide practitioners in all settings regarding the clinical management of women with low-grade serous carcinoma and discuss future opportunities to improve research and patient care.

Chemotherapy response in low-grade serous ovarian carcinoma at a comprehensive cancer center: Readdressing the roles of platinum and cytotoxic therapies

BACKGROUND

Data on platinum sensitivity of low-grade serous ovarian carcinoma (LGSOC) in the upfront setting is lacking, and there is limited and contradictory information on chemotherapy responses in recurrent disease.

METHODS

Patients with LGSOC seen at a comprehensive cancer center from January 1, 1998 to September 30, 2021 were identified from institutional databases. Response to neoadjuvant chemotherapy (NACT) or adjuvant platinum-based chemotherapy and to second- to fifth-line regimens was retrospectively characterized by Response Evaluation Criteria in Solid Tumors (RECIST) v1.1. Wilcoxon rank-sum and two-tailed Fisher exact tests were employed.

RESULTS

Of 50 patients, 12 received platinum doublets for suboptimal residual disease and 11 as NACT. Of 12 patients with suboptimal residual disease, seven (58%) achieved objective responses (five partial responses [PRs] and two complete responses); of the 11 patients who underwent NACT, one (9%) achieved a PR (p = .027). The 15 remaining patients had stable disease on first-line platinum chemotherapy. Of 44 patients who recurred, 20 had RECIST-evaluable responses to second-line and 27 to third-line chemotherapy. Objective response rates to platinum-based chemotherapy were 22% (two of nine) in the second line and 10% (one of 10) in the third. In second and third lines, highest response rates were observed with nonplatinum chemotherapy with bevacizumab, at 100% (two of two) and 30% (three of 10), respectively.

CONCLUSIONS

Primary platinum-based chemotherapy has moderate activity in LGSOC and minimal activity in the recurrent setting, suggesting standard definitions of platinum sensitivity may not apply in LGSOC. In the second and third lines, nonplatinum chemotherapy/bevacizumab elicited the highest response rates.

Do ethnic chinese older adults with epithelial ovarian cancer survive a poorer prognosis?

BACKGROUND

The risk of suffering epithelial ovarian cancer (EOC) for women increases with age evidently, while the prognosis of older EOC patients remain unclear. Against the backdrop of the accelerate aging process in China, this paper investigates whether the older EOC patients have a lower overall survival probability than the younger patients based on the sample of ethnic Chinese population.

METHODS

A total of 323 ethnic Chinese patients diagnosed as epithelial ovarian cancer were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. We compared the overall survival probability between the younger group (< 70 years) and the older patients group (≥ 70 years). Survival curves were drawn using the Kaplan-Meier method, comparisons among different subgroups were evaluated using log-rank tests, and independent prognostic factors were identified by univariate and multivariate Cox regression analyses.

RESULTS

43 patients were (13.3%) in the older patients group and 280 (86.7%) in the younger group. The distribution patterns between two groups were significantly different with regard to marital status, histologic type and FIGO stage. The median overall survival (OS) was significantly longer in the younger group than the older patients group (not reached vs. median 39 months, p < 0.05). The multivariate analysis demonstrated that the age (The older vs. the younger, HR: 1.967, P = 0.007), primary tumor laterality (HR: 1.849, P = 0.009), and FIGO stage (III vs. I, HR: 3.588, P = 0.001; and IV vs. I, HR: 4.382, P = 0.001; respectively) remained as important risk factors while Histology (HGSOC vs. CCOC, HR: 0.479, P = 0.025; and LGSOC/MOC/EC vs. CCOC, HR: 0.390, P = 0.034; respectively) and the number of lymph node dissected more than 10 was a protective factor (HR: 0.397, P = 0.008). In an analysis of 104 pairs of patients matched on the basis of the propensity score, the older patients group had significantly lower overall mortality (HR = 2.561, P = 0.002).

CONCLUSION

Ethnic Chinese Older EOC patients have a worse prognosis than the younger patients.

Stage, treatment and survival of low-grade serous ovarian carcinoma in the Netherlands: A nationwide study

INTRODUCTION

Serous ovarian carcinomas constitute the largest group of epithelial ovarian cancer (60%-75%) and are further classified into high- and low-grade serous carcinoma. Low-grade serous carcinoma (LGSC) is a relatively rare subtype (approximately 5% of serous carcinomas) and epidemiologic studies of large cohorts are scarce. With the present study we aimed to report trends in stage, primary treatment and relative survival of LGSC of the ovary in a large cohort of patients in an effort to identify opportunities to improve clinical practice and outcome of this relatively rare disease.

MATERIAL AND METHODS

Patients diagnosed with LGSC between 2000 and 2019 were identified from the Netherlands Cancer Registry (n = 855). Trends in FIGO stages and primary treatment were analyzed with the Cochran-Armitage trend test, and differences in and trends of 5-year relative survival were analyzed using multivariable Poisson regression.

RESULTS

Over time, LGSC was increasingly diagnosed as stage III (39.9%-59.0%) and IV disease (5.7%-14.4%) and less often as stage I (34.6%-13.5%; p < 0.001). Primary debulking surgery was the most common strategy (76.2%), although interval debulking surgery was preferred more often over the years (10.6%-31.1%; p < 0.001). Following primary surgery, there was >1 cm residual disease in only 15/252 patients (6%), compared with 17/95 patients (17.9%) after interval surgery. Full cohort 5-year survival was 61% and survival after primary debulking surgery was superior to the outcome following interval debulking surgery (60% vs 34%). Survival following primary debulking surgery without macroscopic residual disease (73%) was better compared with ≤1 cm (47%) and >1 cm residual disease (22%). Survival following interval debulking surgery without macroscopic residual disease (51%) was significantly higher than after >1 cm residual disease (24%). Except FIGO stage II (85%-92%), survival did not change significantly over time.

CONCLUSIONS

Over the years, LGSC has been diagnosed as FIGO stage III and stage IV disease more often and interval debulking surgery has been increasingly preferred over primary debulking in these patients. Relative survival did not change over time (except for stage II) and worse survival outcomes after interval debulking surgery were observed. The results support the common recommendation to perform primary debulking surgery in patients eligible for primary surgery.

Low grade serous ovarian cancer - A rare disease with increasing therapeutic options

High-grade serous ovarian cancers (HGSOCs) most commonly arise from the fimbrial end of the fallopian tube and harbor TP53 gene mutations. In contrast, low-grade serous ovarian cancers (LGSOCs) appear to have different pathological, epidemiological, and clinical features and should be seen as a distinct serous epithelial ovarian cancer subtype. Our current understanding of LGSOC is limited, and treatment has generally been derived from the more common HGSOCs due to a lack of separate trial data. LGSOCs are characterized by slow tumor growth and are assumed to develop from serous borderline ovarian tumors as precursors. These cancers are often estrogen-receptor positive and show an activated mitogen-activated protein kinase pathway together with KRAS and BRAF mutations and, rarely, TP53 mutations. These characteristics are now commonly used to guide therapeutical decision making and, consequently, a substantial part of treatment consists of maintenance with endocrine treatment, thus balancing disease stabilization and mild toxicity. Additionally, new trials are ongoing that examine the role of targeted therapies such as MEK inhibitors in combination with endocrine treatments. The purpose of this work is to summarize current knowledge and present ongoing trial efforts for LGSOCs.

The proteome of clear cell ovarian carcinoma

Clear cell ovarian carcinoma (CCOC) is the second most common subtype of epithelial ovarian carcinoma. Late-stage CCOC is not responsive to gold-standard chemotherapy and results in suboptimal outcomes for patients. In-depth molecular insight is urgently needed to stratify the disease and drive therapeutic development. We conducted global proteomics for 192 cases of CCOC and compared these with other epithelial ovarian carcinoma subtypes. Our results showed distinct proteomic differences in CCOC compared with other epithelial ovarian cancer subtypes including alterations in lipid and purine metabolism pathways. Furthermore, we report potential clinically significant proteomic subgroups within CCOC, suggesting the biologic plausibility of stratified treatment for this cancer. Taken together, our results provide a comprehensive understanding of the CCOC proteomic landscape to facilitate future understanding and research of this disease. © 2022 The Pathological Society of Great Britain and Ireland.

Advancements in Low-Grade Serous Carcinoma of the Ovary and Peritoneum

PURPOSE OF REVIEW

Low-grade serous ovarian cancer (LGSOC) is a rare form of epithelial ovarian cancer that generally exhibits a protracted course and is less sensitive to chemotherapy than high-grade serous ovarian cancer. Over the past decade, it has become clear that patients with LGSOC have a clinically distinct course and are molecularly and histologically unique from patients with high-grade serous ovarian cancer.

RECENT FINDINGS

Endocrine therapy is frequently used for the treatment of patients with recurrent LGSOC and is now also part of the standard upfront treatment of this disease, with an ongoing phase III clinical trial seeking to determine if chemotherapy can be eliminated altogether from the initial treatment of LGSOC. Tumors are frequently found to exhibit alterations affecting the mitogen-activated protein kinase (MAPK) pathway, recently leading to developments in the use of targeted treatments for those patients with recurrent disease. LGSOC is a clinically, histologically, and molecularly unique form of epithelial ovarian cancer. Recent advances in the understanding of endocrine and molecular drivers of this disease have led to changes in both the treatment of newly diagnosed and recurrent disease, with ongoing studies focused on refining upfront therapy and seeking novel targeted combinations for those patients with recurrent disease.

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.

MAPK Pathway Genetic Alterations Are Associated with Prolonged Overall Survival in Low-Grade Serous Ovarian Carcinoma

PURPOSE

To characterize the somatic mutational landscape, investigate associations between genetic alterations and clinical outcomes, and determine the prevalence of pathogenic germline mutations in low-grade serous ovarian carcinomas (LGSC).

EXPERIMENTAL DESIGN

Patients with LGSC tumors who underwent panel-based sequencing of up to 505 genes were identified. Data on somatic and germline mutations; copy-number alterations; and clinicopathologic features, including age at diagnosis, platinum sensitivity, and overall survival (OS), were collected.

RESULTS

Following central pathology rereview, 119 patients with LGSC were identified for analysis. Of these, 110 (92%) had advanced-stage disease (stages III/IV). Somatic KRAS (33%), NRAS (11%), EIF1AX (10%), and BRAF (11%) alterations were the most common; MAPK pathway alterations were found in 60% (n = 71) of LGSCs. KRAS mutations were significantly associated with age at diagnosis more than 50 years (P = 0.02) and platinum-sensitive disease (P = 0.03). On multivariate analysis, MAPK pathway alterations (P = 0.02) and platinum sensitivity (P = 0.005) were significantly associated with improved OS. Seventy-nine patients (66%) underwent germline genetic testing; seven pathogenic germline mutations were identified: MUTYH (n = 2), BAP1 (n = 1), RB1 (n = 1), CHEK2 (n = 1), APC (n = 1), and FANCA (n = 1). There were no germline BRCA1/2 mutations. One germline MUTYH-associated LGSC harbored loss-of-heterozygosity at the MUTYH locus, and the patient with the germline BAP1 mutation also harbored a somatic BAP1 frameshift mutation.

CONCLUSIONS

This study showed that MAPK pathway alterations in LGSC, including KRAS mutations, are independently associated with platinum sensitivity and prolonged survival. Germline data, which were limited, identified few pathogenic germline mutations in patients with LGSC. See related commentary by Veneziani and Oza, p. 4357.

Advanced low grade serous ovarian cancer: A retrospective analysis of surgical and chemotherapeutic management in two high volume oncological centers

Simple summary

Low-grade serous ovarian cancer (LGSOC) represents an uncommon histotype of serous ovarian cancer (accounting for approximately 5% of all ovarian cancer) with a distinct behavior compared to its high-grade serous counterpart, characterized by a better prognosis and low response rate to chemotherapeutic agents. Similar to high-grade serous ovarian cancer, cytoreductive surgery is considered crucial for patient survival. This retrospective study aimed to analyze the outcomes of women affected by advanced stages (III–IV FIGO) of LGSOC from two high-volume oncological centers for ovarian neoplasm. In particular, we sought to evaluate the impact on survival outcomes of optimal cytoreductive surgery [i.e., residual disease (RD) &lt;10 mm at the end of surgery]. The results of our work confirm the role of complete cytoreduction (i.e., no evidence of disease after surgery) in the survival of patients and even the positive prognostic role of a minimal RD (i.e., &lt;10 mm), whenever complete cytoreduction cannot be achieved.

Background

Low-grade serous ovarian cancer (LGSOC) is a rare entity with different behavior compared to high-grade serous (HGSOC). Because of its general low chemosensitivity, complete cytoreductive surgery with no residual disease is crucial in advanced stage LGSOC. We evaluated the impact of optimal cytoreduction on survival outcome both at first diagnosis and at recurrence.

Methods

We retrospectively studied consecutive patients diagnosed with advanced LGSOCs who underwent cytoreductive surgery in two oncological centers from January 1994 to December 2018. Survival curves were estimated by the Kaplan–Meier method, and 95% confidence intervals (95% CI) were estimated using the Greenwood formula.

Results

A total of 92 patients were included (median age was 47 years, IQR 35–64). The median overall survival (OS) was 142.3 months in patients with no residual disease (RD), 86.4 months for RD 1–10 mm and 35.2 months for RD &gt;10 mm (p = 0.002). Progression-free survival (PFS) was inversely related to RD after primary cytoreductive surgery (RD = 0 vs RD = 1–10 mm vs RD &gt;10 mm, p = 0.002). On multivariate analysis, RD 1–10 mm (HR = 2.30, 95% CI 1.30–4.06, p = 0.004), RD &gt;10 mm (HR = 3.89, 95% CI 1.92–7.88, p = 0.0004), FIGO stage IV (p = 0.001), and neoadjuvant chemotherapy (NACT) (p = 0.010) were independent predictors of PFS. RD &gt;10 mm (HR = 3.13, 95% CI 1.52–6.46, p = 0.004), FIGO stage IV (p &lt;0.0001) and NACT (p = 0.030) were significantly associated with a lower OS.

Conclusions

Optimal cytoreductive surgery improves survival outcomes in advanced stage LGSOCs. When complete debulking is impossible, a RD &lt;10 mm confers better OS compared to an RD &gt;10 mm in this setting of patients.

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.

CA-125 Levels Are Predictive of Survival in Low-Grade Serous Ovarian Cancer-A Multicenter Analysis

Simple Summary

Low-grade serous cancer (LGSC) accounts for approximately 5% of all ovarian cancers. It is characterized by its high resistance to chemotherapy. Cytoreductive surgery, therefore, is the primary treatment modality for this disease and previous studies have shown that complete removal of all visible tumor tissue should be achieved. In this study, 176 women with LGSC were included and most of them had advanced disease stages, where the disease had already spread. CA-125 is a biomarker that has been previously studied in ovarian cancer. We have found that CA-125 level following treatment of LGSC is an important and independent prognostic factor for progression-free and overall survival. It may be a better surrogate for the true amount of residual disease following treatment compared to the gross estimation of visible residual disease during surgery.

Abstract

Objective: Studies on low-grade serous ovarian cancer (LGSC) are limited by a low number of cases. The aim of this study was to define the prognostic significance of age, stage, and CA-125 levels on survival in a multi-institutional cohort of women with pathologically confirmed LGSC. Methods: Women with LGSC were identified from the collaborative Ovarian Cancer Association Consortium (OCAC). Cases of newly diagnosed primary LGSC were included if peri-operative CA-125 levels were available. Age at diagnosis, FIGO stage, pre- and post-treatment CA-125 levels, residual disease, adjuvant chemotherapy, disease recurrence, and vital status were collected by the participating institutions. Progression-free (PFS) and overall survival (OS) were calculated. Multivariable (MVA) Cox proportional hazard models were used and hazard ratios (HR) calculated. Results: A total of 176 women with LGSC were included in this study; 82% had stage III/IV disease. The median PFS was 2.3 years and the median OS was 6.4 years. Age at diagnosis was not significantly associated with worse PFS (p = 0.23) or OS (p = 0.3) (HR per year: 0.99; 95%CI, 0.96–1.01 and 0.98; 95%CI 0.95–1.01). FIGO stage III/IV was independently associated with PFS (HR 4.26, 95%CI 1.43–12.73) and OS (HR 1.69, 95%CI 0.56–5.05). Elevated CA-125 (≥35 U/mL) at diagnosis was not significantly associated with worse PFS (p = 0.87) or OS (p = 0.78) in MVA. Elevated CA-125 (≥35 U/mL) after completion of primary treatment was independently associated with worse PFS (HR 2.81, 95%CI 1.36–5.81) and OS (HR 6.62, 95%CI 2.45–17.92). In the MVA, residual disease was independently associated with PFS (0.022), but not OS (0.85). Conclusion: Advanced LGSC was associated with poor long-term prognosis. FIGO stage and abnormal post-treatment CA-125 level are key prognostic factors inversely associated with PFS and OS. Highlights: 1. Through a multi-center collaborative effort, data from 176 women with low-grade serous ovarian cancer were analyzed. 2. Although low-grade serous ovarian cancer is often considered indolent, the progression-free and overall survival are poor. 3. Elevated post-treatment CA-125 levels are independently associated with poor survival.

Low-Grade Serous Carcinoma of the Ovary: The Current Status

Low-grade serous carcinoma (LGSC) of the ovary is a rare histological subtype of epithelial ovarian carcinoma. It has distinct clinical behavior and a specific molecular profile. Compared with high-grade serous carcinoma, this tumor presents at a younger age, has an indolent course, and is associated with prolonged survival. LGSC can arise de novo or originate following a serous borderline tumor (SBT). Pathological differentiation between LGSC and other ovarian carcinoma histological subtypes is fundamental. Several factors might influence the overall outcome, such as the age at diagnosis, current smoking, elevated body mass index, mutational status, hormonal receptors’ expression, and Ki-67 proliferation index. Surgery is the main treatment option in LGSC, and efforts must be maximized to achieve a microscopic residual in metastatic disease. Despite being relatively chemo-resistant, adjuvant platinum-based chemotherapy remains the standard of care in LGSC. Hormonal maintenance therapy after adjuvant chemotherapy results in improved outcomes. Treatment options for disease recurrence include secondary cytoreductive surgery, chemotherapy, hormonal therapy, targeted therapy, and clinical trials. Advancements in genomic studies and targeted therapies are expected to change the treatment landscape in LGSC.

Development and Validation of Nomograms to Predict Overall Survival Outcomes in Serous Ovarian Cancer Patients with Satisfactory Cytoreductive Surgery and Chemotherapy

Objective

Nomograms are statistics-based predictive tools that integrate predictive factors. Herein, a nomogram was developed and validated to predict the overall survival (OS) in serous ovarian cancer (SOC).

Methods

Primary SOC patients with satisfactory cytoreductive surgery, chemotherapy, and OS ≥1 month were included in this study. A total of 6957 patients from the Surveillance, Epidemiology, and End Results (SEER) database comprised the training group and 1244 patients comprised the external validation group. The nomogram was structured on Cox models and evaluated in both the training and validation groups using consistency index, area under the receiver operating characteristics curve, calibration plots, and risk subgroup classification. Kaplan–Meier curves were plotted to compare the survival outcomes between subgroups. A decision-curve analysis was used to test the clinical value of the nomogram.

Results

Independent factors, including age, tumor grade, and Federation of Gynecology and Obstetrics (FIGO) stage, identified by multivariate analysis in the training cohort, were selected for the nomogram. The consistency indexes for OS were 0.689 in the training cohort and 0.639 in the validation cohort. The calibration curves showed good consistency between predicted and actual 3- and 5-year OS. Significant differences were observed in the survival curves of different risk subgroups. The decision-curve analysis indicated that our nomogram was superior to the American Joint Committee on Cancer (AJCC) staging system.

Conclusion

A nomogram was constructed to predict the long-term OS in SOC and verified in Asians. The accurate predictions facilitated personalized treatments and follow-up strategies.

The Uncertain Benefit of Adjuvant Chemotherapy in Advanced Low-Grade Serous Ovarian Cancer and the Pivotal Role of Surgical Cytoreduction

In our center, adjuvant chemotherapy is routinely offered in high-grade serous ovarian cancer (HGSOC) patients but less commonly as a standard treatment in low-grade serous ovarian cancer (LGSOC) patients. This study evaluates the efficacy of this paradigm by analysing survival outcomes and by comparing the influence of different clinical and surgical characteristics between women with advanced LGSOC (n = 37) and advanced HGSOC (n = 300). Multivariate analysis was used to identify independent prognostic features for survival in LGSOC and HGSOC. Adjuvant chemotherapy was given in 99.7% of HGSOC patients versus in 27% of LGSOC (p < 0.0001). The LGSOC patients had greater surgical complexity scores (p < 0.0001), more frequent postoperative ICU/HDU admissions (p = 0.0002), and higher peri-/post-operative morbidity (p < 0.0001) compared to the HGSOC patients. The 5-year OS and progression-free survival (PFS) was 30% and 13% for HGSOC versus 57% and 21.6% for LGSOC, p = 0.016 and p = 0.044, respectively. Surgical complexity (HR 5.3, 95%CI 1.2-22.8, p = 0.024) and complete cytoreduction (HR 62.4, 95% CI 6.8-567.9, p < 0.001) were independent prognostic features for OS in LGSOC. This study demonstrates no clear significant survival advantage of chemotherapy in LGSOC. It highlights the substantial survival benefit of dynamic multi-visceral surgery to achieve complete cytoreduction as the primary treatment for LGSOC patients.

Secondary cytoreductive surgery for recurrent low-grade serous ovarian carcinoma: A systematic review and meta-analysis

OBJECTIVES

Low-grade serous ovarian cancer (LGSC) is a relatively chemo-resistant disease with limited effective treatment options for patients with recurrence. Secondary cytoreductive surgery (SCS) is commonly offered at recurrence, although any benefit this has on survival is not fully determined. This review evaluates the impact of SCS, including residual disease, on progression-free survival (PFS) and overall survival (OS) in recurrent LGSC.

METHODS

A comprehensive search of Medline ALL, Embase Classic + Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Web of Science was conducted to obtain studies evaluating optimal or complete SCS versus suboptimal SCS and the amount of residual disease in recurrent LGSC. Meta-analysis was performed and PFS and OS outcomes were calculated.

RESULTS

1Of 5296 studies screened, 350 progressed to full-text review, with 9 ultimately selected for inclusion in the systematic review. Two studies met criteria for meta-analysis of PFS and of OS. The presence of visible residual disease at the conclusion of SCS negatively impacted PFS (HR = 3.51, 95% CI = 1.72-7.14), whereas SCS with no residual disease significantly improved OS (HR = 0.4, 95% CI = 0.23-0.7) in patients with recurrent LGSC. Diffuse and extensive disease distribution was inversely linked to survival. In addition, SCS as an initial treatment for recurrent LGSC was associated with superior survival in comparison to chemotherapy. A short platinum-free interval was not associated with worse survival in this cohort.

CONCLUSIONS

Complete SCS, and to a lesser extent optimal SCS, are associated with improved PFS and OS in patients with recurrent LGSC. SCS may be a better initial treatment strategy than systemic chemotherapy for recurrent disease. Patients with recurrent LGSC should be evaluated for the role of SCS based on disease distribution and functional status, irrespective of the platinum-free interval. Prospective studies are needed to further study the role of SCS in patients with recurrent LGSC.

Systematic Lymph Node Dissection May Be Abolished in Patients With Apparent Early-Stage Low-Grade Mucinous and Endometrioid Epithelial Ovarian Cancer

OBJECTIVE

To investigate whether systematic lymph node dissection can confer clinical benefits in patients with apparent early-stage low-grade epithelial ovarian cancer.

METHODS

Patients with apparent early-stage low-grade epithelial ovarian cancer seen at Peking Union Medical College Hospital from January 1, 2005, to December 31, 2015, were retrospectively enrolled. Patients with other histological types and those who did not receive necessary adjuvant chemotherapy were excluded. Data collection and long-term follow-up were performed. According to the removed lymph node number, three groups based on surgical methods were used: abnormal lymph node resection, pelvic lymphadenectomy, and systematic lymph node dissection to control surgical quality. Their effects on prognosis were analyzed in pathological subgroups.

RESULTS

A total of 196 patients were enrolled; 30.1% of patients had serous, 42.3% of patients had mucinous, and 27.6% of patients had endometrioid carcinoma, of which 51 (26.0%), 96 (49.0), and 49 (25.0%) patients were treated with the above surgical methods, respectively. The occult lymph node metastasis rate was 14 (7.1%), and only five (2.6%) of apparent early-stage patients were upstaged due to lymph node metastasis alone. Systematic lymph node dissection did not benefit progression-free survival or disease-specific overall survival of apparent early-stage low-grade mucinous and endometrioid epithelial ovarian cancer but prolonged progression-free survival of apparent early-stage low-grade serous patients (OR, 0.231, 95% CI, 0.080, 0.668, p = 0.007).

CONCLUSIONS

Systematic lymph node dissection may be abolished in patients with apparent early-stage low-grade mucinous and endometrioid epithelial ovarian cancer but may be considered for apparent early-stage low-grade serous patients.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A Rare Presentation of Choledochoduodenal Fistula Due to Ovarian Cancer Metastasis

Choledochoduodenal fistula (CDF) is an abnormal communication between the common bile duct and the duodenum. It accounts for about 5% to 25% of the total biliary fistulas and is usually due to a perforated duodenal ulcer, choledocholithiasis, and complications secondary to tuberculosis or could be iatrogenic. Primary intrabilliary tumors usually cause obstructive jaundice and rarely biliary metastasis arising from other organs like colon, breast, and lungs can cause obstructive jaundice. There has been a case report of metastasis from ovarian cancer to the major papilla of the duodenum but no reported cases of it causing a CDF. We report a rare case of an 83-year-old female with ovarian cancer who developed a metastatic lesion to the duodenum eventually resulting in a CDF.

Impact of cytoreductive surgery on survival of patients with low-grade serous ovarian carcinoma: A multicentric study of Turkish Society of Gynecologic Oncology (TRSGO-OvCa-001)

BACKGROUND AND OBJECTIVES

The aim of this study was to analyze the factors affecting recurrence-free (RFS) and overall survival (OS) rates of women diagnosed with low-grade serous ovarian cancer (LGSOC).

METHODS

Databases from 13 participating centers in Turkey were searched retrospectively for women who had been treated for stage I-IV LGSOC between 1997 and 2018.

RESULTS

Overall 191 eligible women were included. The median age at diagnosis was 49 years (range, 21-84 years). One hundred seventy-five (92%) patients underwent primary cytoreductive surgery. Complete and optimal cytoreduction was achieved in 148 (77.5%) and 33 (17.3%) patients, respectively. The median follow-up period was 44 months (range, 2-208 months). Multivariate analysis showed the presence of endometriosis (p = .012), lymphovascular space invasion (LVSI) (p = .022), any residual disease (p = .023), and the International Federation of Gynecology and Obstetrics (FIGO) stage II-IV disease (p = .045) were negatively correlated with RFS while the only presence of residual disease (p = .002) and FIGO stage II-IV disease (p = .003) significantly decreased OS.

CONCLUSIONS

The maximal surgical effort is warranted for complete cytoreduction as achieving no residual disease is the single most important variable affecting the survival of patients with LGSOC. The prognostic role of LVSI and endometriosis should be evaluated by further studies as both of these parameters significantly affected RFS.

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.

Clinicopathologic, Immunohistochemical, and Molecular Characteristics of Ovarian Serous Carcinoma With Mixed Morphologic Features of High-grade and Low-grade Serous Carcinoma

Despite the current classification of high-grade serous carcinoma (HGSCA) and low-grade serous carcinoma (LGSCA) as mutually exclusive diseases based on morphology and molecular pathogenesis, cases with mixed morphologic features of HGSCA and LGSCA have been reported. Herein we assess the clinicopathologic, immunohistochemical (IHC), and molecular genetic characteristics of a group of these cases, which we termed indeterminate grade serous carcinoma (IGSCA) in comparison with groups of HGSCA and LGSCA. Using the World Health Organization (WHO) classification criteria, we selected 27 LGSCA and 19 IGSCA for detailed morphologic study. Thirteen classic HGSCA, 19 classic LGSCA, and 19 IGSCA were selected for p53 and BRAF V600E IHC and molecular genetic testing by next-generation sequencing. IGSCA showed the architectural patterns of invasion of LGSCA, but with higher grade nuclear features focally and a mitotic index intermediate between LGSCA and HGSCA. Few cases in the IGSCA group showed mutant TP53 by IHC or sequencing (4/18, 22.2%), 1 case had mutant BRAF non-V600E by sequencing, and 1 had an NRAS mutation. When present, the mutations were identical in the low-grade and high-grade areas. The IGSCA group had a long-term survival similar to the classic HGSCA group. IGSCA with mixed morphologic features of HGSCA and LGSCA is a rare and potentially clinically aggressive variant of serous carcinoma. Their distinct morphologic, but heterogenous molecular features, including low frequency of TP53 and BRAF mutations suggest that these rare tumors may have a different pathogenesis pathway compared with classic HGSCA and classic LGSCA.

An Overview of Candidate Therapeutic Target Genes in Ovarian Cancer

Ovarian cancer (OC) shows the highest mortality rate among gynecological malignancies and, because of the absence of specific symptoms, it is frequently diagnosed at an advanced stage, mainly due to the lack of specific and early biomarkers, such as those based on cancer molecular signature identification. Indeed, although significant progress has been made toward improving the clinical outcome of other cancers, rates of mortality for OC are essentially unchanged since 1980, suggesting the need of new approaches to identify and characterize the molecular mechanisms underlying pathogenesis and progression of these malignancies. In addition, due to the low response rate and the high frequency of resistance to current treatments, emerging therapeutic strategies against OC focus on targeting single factors and pathways specifically involved in tumor growth and metastasis. To date, loss-of-function screenings are extensively applied to identify key drug targets in cancer, seeking for more effective, disease-tailored treatments to overcome lack of response or resistance to current therapies. We review here the information relative to essential genes and functional pathways recently discovered in OC, often strictly interconnected with each other and representing promising biomarkers and molecular targets to treat these malignancies.

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

Low-grade serous ovarian carcinoma (LGSOC) is a distinct pathologic and clinical entity, characterized by less aggressive biological behavior, lower sensitivity to chemotherapy and longer survival compared with high-grade serous ovarian carcinoma. LGSOC often harbors activating mutations of genes involved in mitogen activated protein kinase (MAPK) pathway. Patients with disease confined to the gonad(s) should undergo bilateral salpingo-oophorectomy, total hysterectomy and comprehensive surgical staging, although fertility-sparing surgery can be considered in selected cases. Women with stage IA-IB disease should undergo observation alone after surgery, whereas observation, chemotherapy or endocrine therapy are all possible options for those with stage IC-IIA disease. Patients with advanced disease should undergo primary debulking surgery with the aim of removing all macroscopically detectable disease, whereas neoadjuvant chemotherapy followed by interval debuking surgery. After surgery, the patients can receive either carboplatin plus paclitaxel followed by endocrine therapy or endocrine therapy alone. Molecularly targeted agents, and especially MEK inhibitors and Cyclin-dependent kinase (CDK) inhibitors, are currently under evaluation. Additional research on the genomics of LGSOC and clinical trials on the combination of MEK inhibitors with hormonal agents, other molecularly targeted agents or metformin, are strongly warranted to improve the prognosis of patients with this malignancy.

Should We Abandon Systematic Pelvic and Paraaortic Lymphadenectomy in Low-Grade Serous Ovarian Cancer?

BACKGROUND

Low-grade serous ovarian carcinoma (LGSOC) is a rare disease that accounts for 5% of all ovarian cancers and requires surgical complete debulking. To date, the prognostic value of pelvic and paraaortic lymphadenectomy remains unclear in this population.

PATIENTS AND METHODS

This retrospective cohort of patients with a diagnosis of LGSOC was registered in the Tumeurs Malignes Rares Gynécologiques national network, between January 2000 and July 2017, at 25 centers. All LGSOC were confirmed after pathological review and operated by primary debulking surgery (PDS) or interval debulking surgery after neoadjuvant chemotherapy (NACT-IDS). Primary endpoints were overall survival (OS) and progression-free survival (PFS).

RESULTS

A total of 126 patients were included, 86.1% were stage III/IV, and 74.6% underwent lymph node dissection (LND). According to the Completeness of Cancer Resection (CCR) score, 83.7% had complete resection. Median OS was 130 months, and median PFS was 41 months. Pelvic and paraaortic LND had no significant impact on OS (p = 0.78) or DFS (p = 0.93), and this was confirmed in subgroups (advanced stages FIGO III/IV, CCR score 0/1 or 2/3, and timing of surgery PDS or NACT-IDS). Histological positive paraaortic lymph nodes had a significant negative impact on PFS in the whole population (HR 2.21, 1.18-4.39, p = 0.02) and in the CC0/CC1 population (HR, 2.28, 1.13-4.59, p = 0.02).

CONCLUSIONS

Systematic pelvic and paraaortic LND in patients with LGSOC improved neither overall nor PFS. A prospective trial would be necessary to validate these results but would be difficult to conduct due to the rarity of this disease.

Disparities in care among patients with low-grade serous ovarian carcinoma

OBJECTIVE

Low-grade serous carcinoma (LGSC) is a rare histotype of ovarian cancer with a unique disease course. Little data exist regarding the influence of sociodemographic factors on diagnosis and outcomes in this disease. Our objective was to evaluate the associations between these factors and the clinical characteristics, treatment approaches, and survival in LGSC.

METHODS

The National Cancer Database (NCDB) was queried for data between 2004 and 2015 on patients with LGSC. LGSC was inclusive of invasive, grade 1, serous carcinoma of the ovary, fallopian tube, or peritoneum. Patient demographics, insurance status, disease characteristics, treatment approach, and survival were evaluated. ANOVA, Chi Square, Kaplan-Meier, and Cox regression were used in the analysis.

RESULTS

3221 patients with LGSC were evaluated (89.5% White, 6.2% Black; 7.2% Hispanic, 92.8% non-Hispanic). Compared to Whites, Blacks were diagnosed younger (50.4 vs. 55.9 years, p < 0.01), received less chemotherapy (61.8% vs 67.0%, p = 0.04), and had less CA-125 elevation (OR 4.14 [1.26-13.57], p = 0.02). Compared to non-Hispanics, Hispanics were younger (49.5 vs. 55.8 years, p < 0.01) and received less chemotherapy (55% vs 67%, p < 0.001). In contrast to private insurance, government insurance was associated with a higher 30-day mortality (1.5% vs 0.01%, p < 0.001). Race/ethnicity were not predictive of OS, while older age (HR 1.013 [1.002-1.024], p = 0.03), advanced stage (HR 3.09 [2.15-4.43], p < 0.001), and government insurance (HR 2.33 [1.65-3.30], p < 0.001) were all independently associated with worse OS.

CONCLUSIONS

Significant differences exist in the clinical characteristics, treatments, and outcomes of LGSC by sociodemographics, with Blacks and Hispanics being diagnosed younger and receiving less chemotherapy. Age, stage, and insurance status were predictive of overall survival.

Low-grade Serous Tumors: Are We Making Progress?

PURPOSE OF REVIEW

This review provides an overview of the current clinical standard in low-grade serous ovarian cancer (LGSOC). The available evidence for surgery and standard treatments is elaborated. In addition, we discuss recent findings and novel treatments for LGSOC.

RECENT FINDINGS

Two large multicenter trials studying MEK inhibitors in LGSOC have been presented in the last year. Binimetinib demonstrated an activity in LGSOC, especially in KRAS-mutated disease. Trametinib was associated with an improved progression-free survival in relapsed LGSOC. Based on the current results, MEK inhibitors could be an alternative treatment for LGSOC. Surgery is an important step in the treatment of LGSOC. Hormonal therapy and bevacizumab can be beneficial, next to chemotherapy. Targeted treatments, such as the MEK-inhibitor trametinib, seem to be efficient and should be introduced into clinical practice.

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.

Low-grade serous ovarian carcinoma: A comprehensive literature review

BACKGROUND

Low-grade serous ovarian carcinoma (LGSOC) is a unique entity with clinical and molecular characteristics distinct from high-grade serous ovarian carcinoma (HGSOC). To date the majority of research has focused on the more common HGSOC, with treatment recommendations often extrapolated to LGSOC. Women with LGSOC are typically diagnosed younger and have indolent and relatively chemoresistant disease. Recently there have been major research advances in LGSOC.

AIMS

This systematic review describes the epidemiological, clinical and molecular characteristics of LGSOC, with advances in research and novel treatment options also discussed.

MATERIALS AND METHODS

A 10-year comprehensive systematic review of peer-reviewed literature was conducted, with a total of 132 abstracts read, 89 articles reviewed and 49 included in this review.

RESULTS

This review highlights the clinical and molecular features of LGSOC, current and traditional treatment options and areas of current research into targeted agents.

CONCLUSIONS

Our growing knowledge about LGSOC as a distinct clinical and molecular entity from HGSOC has led to the investigation of more targeted and tailored therapies as their clinical course, optimal management and therapeutic targets differ. There is a need for ongoing collaborative research to provide better treatment options for these patients.

Low-grade serous ovarian carcinoma: an evolution toward targeted therapy

Low-grade serous ovarian carcinoma and its high-grade serous ovarian carcinoma counterpart differ in their precursor lesions, molecular profile, natural history, and response to therapies. As such, low-grade serous ovarian carcinoma needs to be studied separately from high-grade serous ovarian carcinoma, despite challenges stemming from its rarity. A deeper understanding of the pathogenesis of low-grade serous ovarian carcinoma and the most common molecular defects and pathways involved in the carcinogenesis of the ovarian epithelium from normal to serous borderline ovarian tumors to low-grade serous ovarian carcinoma will help develop better therapies. By adopting targeted approaches there may be an opportunity to integrate novel therapies without the need for robust numbers in clinical trials. This manuscript will discuss low-grade serous ovarian carcinoma and focus on the arising treatments being developed with an improved understanding of the pathogenesis of this disease.

Loss of 1p36.33 Frequent in Low-Grade Serous Ovarian Cancer

BACKGROUND: Low-grade serous ovarian cancer (LGSOC) is a rare subtype of epithelial ovarian carcinoma. Limited data regarding the molecular-genetic background exist beyond mutations in the RAS signaling pathway. There is a growing need to better characterize these tumors due to chemoresistance and limited therapeutic options in advanced or recurrent disease. METHODS: We performed genome-wide copy number aberration (CNA) profiles and mutation hotspot screening (KRAS, BRAF, NRAS, ERBB2, PIK3CA, TP53) in 38 LGSOC tumor samples. RESULTS: We detected mutations in the RAS-signaling pathway in 36.8% of cases, including seven KRAS, four BRAF, and three NRAS mutations. We identified two mutations in PIK3CA and one mutation in MAP3K1, EGFR, and TP53. CNAs were detected in 86.5% of cases. None of the focal aberrations was correlated with specific clinical characteristics. The most frequently detected CNA was loss of 1p36.33 in 54.1% of cases, with a trend towards lower progression-free survival and overall survival in patients with 1p36.33 loss. CONCLUSIONS: Activating RAS mutations were dominant in our series, with supplementary detection of two PIK3CA mutations which may lead to therapeutic options. Furthermore, we detected 1p36.33 deletions in half of the cases, indicating a role in tumorigenesis, and these deletions may serve as a prognostic marker.

Maximal cytoreduction is related to improved disease-free survival in low-grade ovarian serous carcinoma

Objective:

To evaluate the factors predicting oncologic outcomes in low-grade ovarian serous carcinoma (LGOSC).

Methods:

Seventy patients with LGOSC were included in the study. According to the residual disease present at the end of the initial cytoreductive surgery (CRS), surgical outcomes are defined as follows: maximal CRS for absence of macroscopic residual tumors, optimal CRS for macroscopic residual tumors with diameters ranging from 0.1 to ⩽1 cm diameter, and suboptimal CRS for macroscopic residual tumors measuring >1 cm in diameter.

Results:

Five-year disease-free survival (DFS) and cancer-specific survival (CSS) were 61% and 83%, respectively. Surgical outcomes were suboptimal in 3 (4.3%) patients, optimal in 8 (11.4%) patients, and maximal in 59 (84.3%) patients. Stage and surgical outcomes were related to DFS ( p < 0.05). Compared with maximal CRS, the presence of residual tumors (suboptimal and optimal debulking) was related to threefold increased risk of disease failure (recurrence or progression) (hazard ratio [95% confidence interval] 3.00 [1.27–7.09]; P=0.012). CSS was associated with disease stage alone ( P=0.03). Advanced stage was related with lower DFS and CSS.

Conclusions:

Maximal CRS facilitates an improvement in DFS. Achieving no residual disease after the completion of surgery should be a cornerstone of LGOSC management.

Ovarian cancer in adolescents and young adults

The diagnosis of ovarian cancer in adolescents and young adults is always challenging. Many issues exist, and most important of these may be access to care with an appropriate provider. A range of histologies occur in the ovaries, and their frequency changes markedly as patients progress from adolescence to young adulthood. The very curable germ cell tumors of adolescence slowly give way to aggressive carcinomas, which require a different treatment approach. Special consideration is needed for treatment of toxicity. In an ideal world, centers consisting of pediatric, medical, and gynecological oncologists may be the most appropriate to care for these complex and diverse patients.

Response to trametinib in recurrent low-grade serous ovarian cancer with NRAS mutation: A case report

Low-grade serous ovarian cancer represents a minority of ovarian cancers and has distinctive features from high grade epithelial ovarian cancer. While less aggressive, in advanced stage they can be poorly chemo-responsive and incur a treatment challenge. Next generation sequencing of tumors has allowed for the potential for targeted therapy in cancer treatment, which can allow for avoidance of traditional cytotoxic chemotherapy. We present a case of a 56 year old female with advanced recurrent low grade serous ovarian cancer found to have NRAS mutation who underwent targeted therapy with trametinib with immediate and sustained disease response. We review the response and toxicity experienced by the patient, as well as treatment for her toxicity.

Treatment of Rare Epithelial Ovarian Tumors

Traditionally, the management of epithelial ovarian cancer has been approached using a one-size-fits-all mentality. This strategy does not acknowledge the differences in epidemiology and clinical behavior of many of the histologic and molecular subgroups of ovarian cancer, specifically the rare histologies. While cytoreductive surgery followed by adjuvant platinum and taxane-based chemotherapy is the mainstay of primary treatment of epithelial ovarian cancer as a group, further investigation of novel therapeutics is critical for improving outcomes of these rare histologies. This article focuses on the management of non-high grade serous histologies of ovarian cancer.

Gynecologic Cancers: Molecular Updates 2018

Ovarian carcinoma continues to be a concern for woman and maintains significant morbidity and mortality. Emerging molecular markers are providing additional opportunities for effective diagnosis and prognosis of disease. An integrated clinicopathologic and molecular classification of gynecologic malignancies has the potential to refine the clinical risk prediction of patients with cancer and to provide more tailored treatment recommendations.

Imaging in the pre-operative staging of ovarian cancer

The main prognostic factor in ovarian cancer is the stage of disease at diagnosis. The staging system in use (FIGO classification, updated in 2014) is based on the surgical-pathological findings. Although surgical staging is the gold standard in ovarian cancer, the initial patient management depends on the imaging-based pre-surgical staging assessment, in order to identify unresectable or difficult to resect disease. Radiologists need to be aware of the strengths of the available imaging modalities, as well as the imaging pitfalls. Clear understanding of pattern of disease spread and review areas are critical for accurate staging and treatment planning. The current standard of care for pre-surgical staging is CT of the thorax, abdomen, and pelvis. This allows a rapid evaluation of disease extent and is fairly accurate in identifying bulky disease but has definite limitations in assessing the extent of small volume disease and in the confirmation of certain sites of disease beyond the abdomen. Functional MRI has been reported to be superior in detecting small peritoneal deposits. PET/CT may be used as a problem-solving tool in some patients where determination remains unclear, particularly in confirmation of advanced stage beyond the abdomen.

Response to trametinib in recurrent low-grade serous ovarian cancer with NRAS mutation: A case report

Low-grade serous ovarian cancer represents a minority of ovarian cancers and has distinctive features from high grade epithelial ovarian cancer. While less aggressive, in advanced stage they can be poorly chemo-responsive and incur a treatment challenge. Next generation sequencing of tumors has allowed for the potential for targeted therapy in cancer treatment, which can allow for avoidance of traditional cytotoxic chemotherapy. We present a case of a 56 year old female with advanced recurrent low grade serous ovarian cancer found to have NRAS mutation who underwent targeted therapy with trametinib with immediate and sustained disease response. We review the response and toxicity experienced by the patient, as well as treatment for her toxicity.

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Trametinib was effective in low grade ovarian cancer with NRAS mutation.

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Next generation sequencing of tumors can provide new options.

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Common side effects of trametinib can be managed with dose reduction.

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.