Trends of low-grade serous ovarian carcinoma in the United States

Risk Factors for Recurrence in Serous Borderline Ovarian Tumors and Early-Stage Low-Grade Serous Ovarian Carcinoma

BACKGROUND

Tumor recurrence significantly impacts the quality of life and fertility of patients with serous borderline ovarian tumors (SBOT) and early-stage low-grade serous ovarian carcinoma (LGSOC). This study aims to characterize recurrence patterns, identify independent risk factors for recurrence, and develop a nomogram to predict recurrence-free survival (RFS).

METHODS

We conducted a retrospective case-control study to investigate recurrence in patients undergoing fertility-sparing surgery (FSS) and radical surgery (RS). Logistic regression and Cox regression were used to identify risk factors. Kaplan-Meier analysis was applied to evaluate RFS. A nomogram was developed based on identified variables to predict RFS.

RESULTS

Tumor capsule disruption and micropapillary were associated with higher recurrence risk in the FSS group. Non-invasive implants were associated with higher recurrence risk in the RS group. The nomogram prediction model was developed based on identified risk factors. The area under the curve (AUC) for RFS predictions was 0.74 (95% CI: 0.62-0.85) at 3 years and 0.78 (95% CI: 0.67-0.89) at 5 years for the FSS group and 0.87 (95% CI: 0.76-0.98) at 3 years and 0.81 (95% CI: 0.65-0.97) at 5 years for the RS group.

CONCLUSIONS

We identified the risk factors for recurrence of SBOT and early-stage LGSOC following FSS and RS procedures and developed a predictive model for forecasting RFS. This model provides valuable guidance for patients and clinicians in predicting recurrence risk for patients.

Primary versus interval cytoreductive surgery in patients with rare epithelial or non-epithelial ovarian cancer

BACKGROUND

The standard treatment for advanced epithelial ovarian cancer is primary cytoreductive surgery, with the goal of achieving no residual disease. Neoadjuvant chemotherapy and interval cytoreductive surgery can be viable treatment options for patients with extensive disease that precludes complete tumor removal during initial surgery, or when significant comorbidities increase the surgical risk without adversely impacting overall survival rates. However, published studies mostly included patients with high-grade serous ovarian cancer, with an underrepresentation of non-high-grade serous epithelial and non-epithelial cancers. This review aimed to provide an overview of the available data on the outcomes of primary cytoreductive surgery versus interval cytoreduction in patients with rare ovarian cancer histotypes.

METHODS

Published literature on primary versus interval cytoreductive surgery in non-high-grade serous ovarian cancers from 2004 to 2024 was searched using PubMed, EMBASE, and Google Scholar and reported for each histological subtype. The outcomes of patients with low-grade serous, endometrioid, clear-cell, and mucinous carcinomas after neoadjuvant chemotherapy were reviewed. Furthermore, the results following neoadjuvant chemotherapy in non-epithelial ovarian cancers, such as ovarian germ cell tumors, sex cord-stromal tumors, and small-cell carcinoma of the ovary, have also been reported. Most data were derived from retrospective studies, with heterogeneity in design.

RESULTS & CONCLUSIONS

Several ovarian cancer histotypes, including low-grade serous and mucinous carcinomas, may be less responsive than high-grade serous carcinomas to neoadjuvant chemotherapy. Consequently, primary cytoreduction with maximal surgical effort may confer a survival advantage. Other tumors responded well to neoadjuvant chemotherapy, allowing for interval fertility-sparing surgeries. Additional evidence is required because no prospective studies are currently available. Given the low incidence of these diseases, randomized controlled trials may not be feasible. However, national or international registries could play a pivotal role in determining the optimal approach for managing patients with these rare histotypes.

Molecular changes driving low-grade serous ovarian cancer and implications for treatment

Low-grade serous ovarian cancer was previously thought to be a subtype of high-grade serous ovarian cancer, but it is now recognized as a distinct disease with unique clinical and molecular behaviors. The disease may arise de novo or develop from a serous borderline ovarian tumor. Although it is more indolent than high-grade serous ovarian cancer, most patients have advanced metastatic disease at diagnosis and recurrence is common. Recurrent low-grade serous ovarian cancer is often resistant to standard platinum-taxane chemotherapy, making it difficult to treat with the options currently available. New targeted therapies are needed, but their development is contingent on a deeper understanding of the specific biology of the disease. The known molecular drivers of low-grade tumors are strong hormone receptor expression, mutations in the mitogen-activated protein kinase (MAPK) pathway (KRAS, BRAF, and NRAS), and in genes related to the MAPK pathway (NF1/2, EIF1AX, and ERBB2). However, MAPK inhibitors have shown only modest clinical responses. Based on the discovery of CDKN2A mutations in low-grade serous ovarian cancer, cyclin-dependent kinases 4 and 6 (CDK4/6) inhibitors are now being tested in clinical trials in combination with hormone therapy. Additional mutations seen in a smaller population of low-grade tumors include USP9X, ARID1A, and PIK3CA, but no specific therapies targeting them have been tested clinically. This review summarizes the clinical, pathologic, and molecular features of low-grade serous ovarian cancer as they are now understood and introduces potential therapeutic targets and new avenues for research.

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.

Primary ovarian cancer combined with primary fallopian tube cancer: A case report

BACKGROUND

Low grade serous carcinoma of the ovary (LGSOC) is a rare type of epithelial ovarian cancer with a low incidence rate. The origin of ovarian cancer has always been a hot topic in gynecological oncology research, and some scholars believe that the origin of ovarian malignant tumors is the fallopian tubes. Primary fallopian tube cancer is the lowest incidence of malignant tumors in the female reproductive system. There are only a few reports in the literature, but the mortality rate is very high. But in clinical practice, fallopian tube cancer is very common, but in most cases, it is classified as ovarian cancer.

CASE SUMMARY

We report a 54 years old postmenopausal woman who was hospitalized with a lower abdominal mass and underwent surgical treatment. The final pathological confirmation was low-grade serous carcinoma of the right ovary and low-grade serous carcinoma of the left fallopian tube. No special treatment was performed after the surgery, and the patient was instructed to undergo regular follow-up without any signs of disease progression.

CONCLUSION

The prognosis of LGSOC is relatively good, over 80% of patients still experience disease recurrence.

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.

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 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.

The highs and lows of serous ovarian cancer

Low-grade serous ovarian cancer was initially described as a distinct type of rare epithelial ovarian cancer 20 years ago; however, only recently have physicians begun to leverage the understanding of the clinical behavior and molecular profile of this disease for treatment. The use of routine next-generation sequencing has allowed a deeper understanding of the molecular drivers of this disease and shown how molecular alterations in mitogen-activated protein kinase pathway genes such as KRAS and BRAF can affect overall prognosis and disease behavior. The use of targeted therapies, including MEK inhibitors, BRAF kinase inhibitors, and other investigational targeted therapies are changing the way this disease is viewed and treated. In addition, endocrine therapy can provide prolonged disease stability with generally mild toxicity, as well as promising response rates in recent studies examining combination therapy with CDK 4/6 inhibitors in the upfront and recurrent setting. Once seen merely as a chemo-resistant form of ovarian cancer, recent studies have worked to harness the unique features of low-grade serous ovarian cancer to provide individualized treatment options for patients with this disease.

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.

Underlying mechanisms of change in cancer prevalence in older U.S. adults: contributions of incidence, survival, and ascertainment at early stages

PURPOSE

To quantitatively evaluate contributions of trends in incidence, relative survival, and stage at diagnosis to the dynamics in the prevalence of major cancers (lung, prostate, colon, breast, urinary bladder, ovaries, stomach, pancreas, esophagus, kidney, liver, and skin melanoma) among older U.S. adults age 65 +.

METHODS

Trend partitioning was applied to the Surveillance, Epidemiology, and End Results Program data for 1973-2016.

RESULTS

Growth of cancer prevalence in older adults decelerated or even decreased over time for all studied cancers due to decreasing incidence and improving survival for most of cancers, with a smaller contribution of the stage at cancer diagnosis. Changes in the prevalence of cancers of the lung, colon, stomach, and breast were predominantly due to decreasing incidence, increasing survival and more frequent diagnoses at earlier stages. Changes in prevalence of some other cancers demonstrated adverse trends such as decreasing survival in localized and regional stages (urinary bladder and ovarian) and growing impact of late-stage diagnoses (esophageal cancer).

CONCLUSION

While decelerating or decreasing prevalence of many cancers were due to a beneficial combination of decreasing incidence and increasing survival, there are cancers for which decelerating prevalence is due to lack of improvement in their stage-specific survival and/or increasing frequency of diagnosis at advanced stages. Overall, if the observed trends persist, it is likely that the burden associated with cancer prevalence in older U.S. adults will be lower  comparing to projections based on constant increasing prevalence have previously estimated.

Versican secreted by the ovary links ovulation and migration in fallopian tube derived serous cancer

High grade serous ovarian cancers (HGSOC) predominantly arise in the fallopian tube epithelium (FTE) and colonize the ovary first, before further metastasis to the peritoneum. Ovarian cancer risk is directly related to the number of ovulations, suggesting that the ovary may secrete specific factors that act as chemoattractants for fallopian tube derived tumor cells during ovulation. We found that 3D ovarian organ culture produced a secreted factor that enhanced the migration of FTE non-tumorigenic cells as well as cells harboring specific pathway modifications commonly found in high grade serous cancers. Through size fractionation and a small molecule inhibitors screen, the secreted protein was determined to be 50-100kDa in size and acted through the Epidermal Growth Factor Receptor (EGFR). To correlate the candidates with ovulation, the PREDICT organ-on-chip system was optimized to support ovulation in a perfused microfluidic platform. Versican was found in the correct molecular weight range, contained EGF-like domains, and correlated with ovulation in the PREDICT system. Exogenous versican increased migration, invasion, and enhanced adhesion of both murine and human FTE cells to the ovary in an EGFR-dependent manner. The identification of a protein secreted during ovulation that impacts the ability of FTE cells to colonize the ovary provides new insights into the development of strategies for limiting primary ovarian metastasis.

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.

STING pathway expression in low-grade serous carcinoma of the ovary: an unexpected therapeutic opportunity?

Ovarian carcinoma histotypes are distinct diseases with variable clinical outcomes and response to treatment. There is a need for new subtype-specific treatment modalities, especially for women with widespread and chemo-resistant disease. Stimulator of interferon genes (STING) is a part of the cGAS-STING pathway that mediates innate immune defence against infectious DNA-containing pathogens and also detects tumour-derived DNA and generates intrinsic antitumour immunity. The STING signalling pathway is suppressed by several mechanisms in a variety of malignant diseases and, in some cancers that may be a requirement for cellular transformation. The aim of this study was to use immunohistochemistry to evaluate STING protein expression across normal tissue, paratubal and ovarian cysts, and ovarian tumour histotypes including ovarian carcinomas. Herein, we show that the fallopian tube ciliated cells express STING protein, whereas the secretory cells are negative. STING expression differs among ovarian cancer histotypes; low-grade serous ovarian carcinomas and serous borderline tumours have uniform high STING expression, while high-grade serous and endometrioid carcinomas have heterogeneous expression, and clear cell and mucinous carcinomas show low expression. As low-grade serous carcinomas are known to be genomically stable and typically lack a prominent host immune response, the consistently high STING expression is unexpected. High STING expression may reflect pathway activation or histogenesis and the mechanisms may be different in different ovarian carcinoma histotypes. Further studies are needed to determine whether the STING signalling pathway is active and whether these tumours would be candidates for therapeutic interventions that trigger innate immunity activation.

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.

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.

Cost-effectiveness of maintenance hormonal therapy in patients with advanced low grade serous ovarian cancer

OBJECTIVES

To assess the cost-effectiveness of using maintenance hormonal therapy in patients with low grade serous ovarian cancer (LGSC).

METHODS

A simulated decision analysis with a Markov decision model over a lifetime horizon was performed using the base case of a 47-year old patient with stage IIIC, LGSC following first-line treatment with primary cytoreductive surgery and adjuvant chemotherapy. Two treatment strategies were analyzed - maintenance daily letrozole until disease progression and routine observation. The analysis was from the perspective of the healthcare payer. Direct medical costs were estimated using public data sources and previous literature and were reported in adjusted 2018 Canadian dollars. The model estimated lifetime cost, quality-adjusted life years (QALY), life years (LY), median overall survival (OS), and number of recurrences with each strategy. Cost-effectiveness was compared using an incremental cost-effectiveness ratio (ICER). A strategy was considered cost-effective when the ICER was less than the willingness to pay (WTP) threshold of $50,000 CAD per QALY. Deterministic sensitivity analysis was performed to assess the impact of changing key clinical and cost variables.

RESULTS

Maintenance letrozole was the preferred strategy with an associated lifetime cost of $69,985 CAD ($52,620 USD) and an observed improvement of 0.91 QALYs and 1.55 LYs. The ICER for letrozole maintenance therapy was an additional $11,037 CAD ($8298 USD) per QALY. The modeled median OS was 150 months with maintenance letrozole and 126 months in the observation strategy. The maintenance letrozole strategy resulted in 34% and 17% fewer first recurrences at 5-year and 10-year follow-up, respectively.

CONCLUSION

Maintenance letrozole is a cost-effective treatment strategy in patients with advanced LGSC resulting in clinically-relevant improvement in QALYs, LYs, and fewer disease recurrences.

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.

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 carcinoma (LGSC): A Canadian multicenter review of practice patterns and patient outcomes

OBJECTIVE

Patients with advanced low-grade serous carcinoma (LGSC) have poor long-term survival rates. As a rare histotype, there are uncertainties regarding the use of current therapies. Thus, we studied practice patterns and treatment outcomes as part of a national initiative to better understand and improve the care of women with advanced LGSC.

METHODS

This retrospective cohort study was conducted in 5 Canadian referral institutions from 2000 to 2016. Data collection and pathology reporting were standardized. Outcome measures included overall survival (OS), progression-free survival (PFS), progression-free intervals (PFI), and time to next treatment (TTNT). Cox regression analysis was used to evaluate the effects of clinical and pathologic factors on outcomes and prognosis.

RESULTS

There were 134 patients (stage II-IV) with a median follow-up of 32.4 months (range 1.6-228). Four primary treatments were compared across institutions: 1) surgery followed by chemotherapy (56%), 2) neoadjuvant chemotherapy (NACT) followed by surgery (27%), 3) surgery alone (9%), and 4) surgery followed by anti-hormone therapy (4%). Primary platinum/paclitaxel chemotherapy was used in 81%. Patients treated with NACT had worse PFS. Multivariable Cox regression analysis identified lesser residual disease, younger age, and primary peritoneal origin as variables significantly associated with better OS/PFS (p < 0.03). One institution had significantly better PFS than the others (p = 0.025), but this finding could be related to a higher frequency of primary peritoneal LGSC. PFI and TTNT intervals in patients with relapsed disease were not significantly different after the first relapse irrespective of treatment type.

CONCLUSIONS

There are notable differences in practice patterns across Canada. This underscores the need for ongoing strategies to measure, evaluate and achieve optimal patient outcomes for women with advanced LGSC.

Low-grade serous ovarian cancer: State of the science

In January 2019, a group of basic, translational, and clinical investigators and patient advocates assembled in Miami, Florida, to discuss the current state of the science of low-grade serous carcinoma of the ovary or peritoneum-a rare ovarian cancer subtype that may arise de novo or following a diagnosis of serous borderline tumor. The purpose of the conference was to review current knowledge, discuss ongoing research by established researchers, and frame critical questions or issues for future directions. Following presentations and discussions, the primary objective was to initiate future collaborations, uniform database platforms, laboratory studies, and clinical trials to better understand this disease and to advance clinical care outside the boundaries of single academic institutions. This review summarizes the state of the science in five principal categories: epidemiology and patient outcomes, pathology, translational research, patient care and clinical trials, and patients' perspective.

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.

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.

Markers of MEK inhibitor resistance in low-grade serous ovarian cancer: EGFR is a potential therapeutic target

BACKGROUND

Although low-grade serous ovarian cancer (LGSC) is rare, case-fatality rates are high as most patients present with advanced disease and current cytotoxic therapies are not overly effective. Recognizing that these cancers may be driven by MAPK pathway activation, MEK inhibitors (MEKi) are being tested in clinical trials. LGSC respond to MEKi only in a subgroup of patients, so predictive biomarkers and better therapies will be needed.

METHODS

We evaluated a number of patient-derived LGSC cell lines, previously classified according to their MEKi sensitivity. Two cell lines were genomically compared against their matching tumors samples. MEKi-sensitive and MEKi-resistant lines were compared using whole exome sequencing and reverse phase protein array. Two treatment combinations targeting MEKi resistance markers were also evaluated using cell proliferation, cell viability, cell signaling, and drug synergism assays.

RESULTS

Low-grade serous ovarian cancer cell lines recapitulated the genomic aberrations from their matching tumor samples. We identified three potential predictive biomarkers that distinguish MEKi sensitive and resistant lines: KRAS mutation status, and EGFR and PKC-alpha protein expression. The biomarkers were validated in three newly developed LGSC cell lines. Sub-lethal combination of MEK and EGFR inhibition showed drug synergy and caused complete cell death in two of four MEKi-resistant cell lines tested.

CONCLUSIONS

KRAS mutations and the protein expression of EGFR and PKC-alpha should be evaluated as predictive biomarkers in patients with LGSC treated with MEKi. Combination therapy using a MEKi with EGFR inhibition may represent a promising new therapy for patients with MEKi-resistant LGSC.

Markers of MEK inhibitor resistance in low-grade serous ovarian cancer: EGFR is a potential therapeutic target

Background

Although low-grade serous ovarian cancer (LGSC) is rare, case-fatality rates are high as most patients present with advanced disease and current cytotoxic therapies are not overly effective. Recognizing that these cancers may be driven by MAPK pathway activation, MEK inhibitors (MEKi) are being tested in clinical trials. LGSC respond to MEKi only in a subgroup of patients, so predictive biomarkers and better therapies will be needed.

Methods

We evaluated a number of patient-derived LGSC cell lines, previously classified according to their MEKi sensitivity. Two cell lines were genomically compared against their matching tumors samples. MEKi-sensitive and MEKi-resistant lines were compared using whole exome sequencing and reverse phase protein array. Two treatment combinations targeting MEKi resistance markers were also evaluated using cell proliferation, cell viability, cell signaling, and drug synergism assays.

Results

Low-grade serous ovarian cancer cell lines recapitulated the genomic aberrations from their matching tumor samples. We identified three potential predictive biomarkers that distinguish MEKi sensitive and resistant lines: KRAS mutation status, and EGFR and PKC-alpha protein expression. The biomarkers were validated in three newly developed LGSC cell lines. Sub-lethal combination of MEK and EGFR inhibition showed drug synergy and caused complete cell death in two of four MEKi-resistant cell lines tested.

Conclusions

KRAS mutations and the protein expression of EGFR and PKC-alpha should be evaluated as predictive biomarkers in patients with LGSC treated with MEKi. Combination therapy using a MEKi with EGFR inhibition may represent a promising new therapy for patients with MEKi-resistant LGSC.

Markers of MEK inhibitor resistance in low-grade serous ovarian cancer: EGFR is a potential therapeutic target

Background

Although low-grade serous ovarian cancer (LGSC) is rare, case-fatality rates are high as most patients present with advanced disease and current cytotoxic therapies are not overly effective. Recognizing that these cancers may be driven by MAPK pathway activation, MEK inhibitors (MEKi) are being tested in clinical trials. LGSC respond to MEKi only in a subgroup of patients, so predictive biomarkers and better therapies will be needed.

Methods

We evaluated a number of patient-derived LGSC cell lines, previously classified according to their MEKi sensitivity. Two cell lines were genomically compared against their matching tumors samples. MEKi-sensitive and MEKi-resistant lines were compared using whole exome sequencing and reverse phase protein array. Two treatment combinations targeting MEKi resistance markers were also evaluated using cell proliferation, cell viability, cell signaling, and drug synergism assays.

Results

Low-grade serous ovarian cancer cell lines recapitulated the genomic aberrations from their matching tumor samples. We identified three potential predictive biomarkers that distinguish MEKi sensitive and resistant lines: KRAS mutation status, and EGFR and PKC-alpha protein expression. The biomarkers were validated in three newly developed LGSC cell lines. Sub-lethal combination of MEK and EGFR inhibition showed drug synergy and caused complete cell death in two of four MEKi-resistant cell lines tested.

Conclusions

KRAS mutations and the protein expression of EGFR and PKC-alpha should be evaluated as predictive biomarkers in patients with LGSC treated with MEKi. Combination therapy using a MEKi with EGFR inhibition may represent a promising new therapy for patients with MEKi-resistant LGSC.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0725-1) contains supplementary material, which is available to authorized users.

The Evolving Landscape of Chemotherapy in Newly Diagnosed Advanced Epithelial Ovarian Cancer

The treatment of women with advanced-stage epithelial ovarian cancer (EOC) is aggressive surgical cytoreduction and a combination of platinum plus taxane chemotherapy. The timing and extent of surgery has direct implications on the selection of subsequent treatment as well as the prognosis of patients with EOC. Frontline chemotherapeutic regimens have evolved through a series of large multi-institutional randomized clinical trials that focused on targeted agents as maintenance therapy. On June 13, 2018, the U.S. Food and Drug Administration (FDA) approved adding bevacizumab to adjuvant intravenous chemotherapy followed by maintenance based on the results of Gynecologic Oncology Group protocol 218. Maintenance olaparib was FDA-approved on December 19, 2018, for frontline maintenance among those with advanced EOC who respond to frontline chemotherapy and harbor a germline or somatic BRCA1 or BRCA2 mutation. This was based on the results of SOLO-1. Despite a strong rationale and extensive study, intraperitoneal chemotherapy has not been adopted in clinical practice. Alternatively, heated intraperitoneal chemotherapy has shown promise as a more tolerable and technically feasible method of regional therapy, but widespread application will require more evidence. Significant strides have also been made in understanding the biology of EOC, resulting in a personalized approach to first-line therapy. One approach calls for recognizing differences in histologic subtypes and molecular alterations, which may open up alternative therapeutic interventions.

The detrimental effect of adopting interval debulking surgery in advanced stage low-grade serous ovarian cancer

OBJECTIVE

To examine outcomes of patients having treatments for newly diagnosed advanced stage low-grade serous ovarian cancer (LGSC).

METHODS

We conducted a retrospective case series of women affected by advanced stage (stage IIIB or more) LGSC undergoing surgery in a single oncologic center between January 2000 and December 2017. Survival outcomes were assessed using Kaplan-Meier and Cox models.

RESULTS

Data of 72 patients were retrieved. Primary cytoreductive surgery was attempted in 68 (94.4%) patients: 19 (27.9%) had residual disease (RD) >1 cm after primary surgery. Interval debulking surgery (IDS) was attempted in 15 of these 19 (78.9%) patients and the remaining 4 patients having not primary debulking surgery. Twelve out of 19 (63.1%) patients having IDS had RD. After a mean (±standard deviation) follow-up was 61.6 (±37.2) months, 50 (69.4%) and 22 (30.5%) patients recurred and died of disease, respectively. Via multivariate analysis, non-optimal cytoreduction (hazard ratio [HR]=2.79; 95% confidence interval [CI]=1.16-6.70; p=0.021) and International Federation of Obstetrics and Gynecologists (FIGO) stage IV (HR=3.15; 95% CI=1.29-7.66; p=0.011) were associated with worse disease-free survival. Via multivariate analysis, absence of significant comorbidities (HR=0.56; 95% CI=0.29-1.10; p=0.093) and primary instead of IDS (HR=2.95; 95% CI=1.12-7.74; p=0.027) were independently associated with an improved overall survival.

CONCLUSION

LGSC is at high risk of early recurrence. However, owing to the indolent nature of the disease, the majority of patients are long-term survivors. Further prospective studies and innovative treatment modalities are warranted to improve patients care.

Adequate pelvic lymphadenectomy and survival of women with early-stage epithelial ovarian cancer

OBJECTIVE

To examine the trends and survival for women with early-stage epithelial ovarian cancer who underwent adequate lymphadenectomy during surgical treatment.

METHODS

This is a retrospective observational study examining the Surveillance, Epidemiology, End Results program between 1988 and 2013. We evaluated 21,537 cases of stage I-II epithelial ovarian cancer including serous (n=7,466), clear cell (n=6,903), mucinous (n=4,066), and endometrioid (n=3,102) histology. A time-trend analysis of the proportion of patients who underwent adequate pelvic lymphadenectomy (≥8 per Gynecologic Oncology Group [GOG] criteria, ≥12 per Collaborative Group Report [CGR] criteria for bladder cancer, and >22 per Mayo criteria for endometrial cancer) and a survival analysis associated with adequate pelvic lymphadenectomy were performed.

RESULTS

There were significant increases in the proportion of women who underwent adequate lymphadenectomy: GOG criteria 3.6% to 28.6% (1988-2010); CGR criteria 2.4% to 22.4% (1988-2013); and Mayo criteria 0.7% to 9.5% (1988-2013) (all, p<0.05). On multivariable analysis, adequate lymphadenectomy was independently associated with improved cause-specific survival compared to inadequate lymphadenectomy: GOG criteria, adjusted-hazard ratio (HR)=0.75, CGR criteria, adjusted-HR=0.77, and Mayo criteria, adjusted-HR=0.85 (all, p<0.05). Compared to inadequate lymphadenectomy, adequate lymphadenectomy was significantly associated with improved cause-specific survival for serous (HR range=0.67-0.73), endometrioid (HR range=0.59-0.61), and clear cell types (HR range=0.66-0.73) (all, p<0.05) but not in mucinous type (HR range=0.80-0.91; p>0.05).

CONCLUSION

Quality of lymphadenectomy during the surgical treatment for early-stage epithelial ovarian cancer has significantly improved. Adequate lymphadenectomy is associated with a 15%-25% reduction in ovarian cancer mortality compared to inadequate lymphadenectomy.