Cigarette smoking and risk of ovarian cancer: a pooled analysis of 21 case-control studies

Global epidemiology of epithelial ovarian cancer

Globally, ovarian cancer is the eighth most common cancer in women, accounting for an estimated 3.7% of cases and 4.7% of cancer deaths in 2020. Until the early 2000s, age-standardized incidence was highest in northern Europe and North America, but this trend has changed; incidence is now declining in these regions and increasing in parts of eastern Europe and Asia. Ovarian cancer is a very heterogeneous disease and, even among the most common type, namely epithelial ovarian cancer, five major clinically and genetically distinct histotypes exist. Most high-grade serous ovarian carcinomas are now recognized to originate in the fimbrial ends of the fallopian tube. This knowledge has led to more cancers being coded as fallopian tube in origin, which probably explains some of the apparent declines in ovarian cancer incidence, particularly in high-income countries; however, it also suggests that opportunistic salpingectomy offers an important opportunity for prevention. The five histotypes share several reproductive and hormonal risk factors, although differences also exist. In this Review, we summarize the epidemiology of this complex disease, comparing the different histotypes, and consider the potential for prevention. We also discuss how changes in the prevalence of risk and protective factors might have contributed to the observed changes in incidence and what this might mean for incidence in the future.

Risk Factors for Ovarian Cancer by BRCA Status: A Collaborative Case-Only Analysis

BACKGROUND

Women with an inherited pathogenic variant in BRCA1 or BRCA2 have a greatly increased risk of developing ovarian cancer, but the importance of behavioral factors is less clear. We used a case-only design to compare the magnitude of associations with established reproductive, hormonal, and lifestyle risk factors between BRCA mutation carriers and noncarriers.

METHODS

We pooled data from five studies from the Ovarian Cancer Association Consortium including 637 BRCA carriers and 4,289 noncarriers. Covariate-adjusted generalized linear mixed models were used to estimate interaction risk ratios (IRR) and 95% confidence intervals (CI), with BRCA (carrier vs. noncarrier) as the response variable.

RESULTS

IRRs were above 1.0 for known protective factors including ever being pregnant (IRR = 1.29, 95% CI; 1.00-1.67) and ever using the oral contraceptive pill (1.30, 95% CI; 1.07-1.60), suggesting the protective effects of these factors may be reduced in carriers compared with noncarriers. Conversely, the IRRs for risk factors including endometriosis and menopausal hormone therapy were below 1.0, suggesting weaker positive associations among BRCA carriers. In contrast, associations with lifestyle factors including smoking, physical inactivity, body mass index, and aspirin use did not appear to differ by BRCA status.

CONCLUSIONS

Our results suggest that associations with hormonal and reproductive factors are generally weaker for those with a pathogenic BRCA variant than those without, while associations with modifiable lifestyle factors are similar for carriers and noncarriers.

IMPACT

Advice to maintain a healthy weight, be physically active, and refrain from smoking will therefore benefit BRCA carriers as well as noncarriers.

Getting to know ovarian cancer: Focusing on the effect of LncRNAs in this cancer and the effective signaling pathways

This article undertakes a comprehensive investigation of ovarian cancer, examining the complex nature of this challenging disease. The main focus is on understanding the role of long non-coding RNAs (lncRNAs) in the context of ovarian cancer (OC), and their regulatory functions in disease progression. Through extensive research, the article identifies specific lncRNAs that play significant roles in the intricate molecular processes of OC. Furthermore, the study examines the signaling pathways involved in the development of OC, providing a detailed comprehension of the underlying molecular mechanisms. By connecting lncRNA dynamics with signaling pathways, this exploration not only advances our understanding of ovarian cancer but also reveals potential targets for therapeutic interventions. The findings open up opportunities for targeted treatments, highlighting the importance of personalized approaches in addressing this complex disease and driving progress in ovarian cancer research and treatment strategies.

Systematic replication of smoking disease associations using survey responses and EHR data in the All of Us Research Program

OBJECTIVE

The All of Us Research Program (All of Us) aims to recruit over a million participants to further precision medicine. Essential to the verification of biobanks is a replication of known associations to establish validity. Here, we evaluated how well All of Us data replicated known cigarette smoking associations.

MATERIALS AND METHODS

We defined smoking exposure as follows: (1) an EHR Smoking exposure that used International Classification of Disease codes; (2) participant provided information (PPI) Ever Smoking; and, (3) PPI Current Smoking, both from the lifestyle survey. We performed a phenome-wide association study (PheWAS) for each smoking exposure measurement type. For each, we compared the effect sizes derived from the PheWAS to published meta-analyses that studied cigarette smoking from PubMed. We defined two levels of replication of meta-analyses: (1) nominally replicated: which required agreement of direction of effect size, and (2) fully replicated: which required overlap of confidence intervals.

RESULTS

PheWASes with EHR Smoking, PPI Ever Smoking, and PPI Current Smoking revealed 736, 492, and 639 phenome-wide significant associations, respectively. We identified 165 meta-analyses representing 99 distinct phenotypes that could be matched to EHR phenotypes. At P < .05, 74 were nominally replicated and 55 were fully replicated. At P < 2.68 × 10-5 (Bonferroni threshold), 58 were nominally replicated and 40 were fully replicated.

DISCUSSION

Most phenotypes found in published meta-analyses associated with smoking were nominally replicated in All of Us. Both survey and EHR definitions for smoking produced similar results.

CONCLUSION

This study demonstrated the feasibility of studying common exposures using All of Us data.

Risks of non-ovarian cancers in women with borderline ovarian tumor: a national cohort study in Sweden

BACKGROUND

Associations between different cancer types are known. The affirmation of the risk for non-ovarian cancer after ovarian borderline tumors (BOT) is, however, sparse.

AIM

To analyze the risk of subsequent or simultaneous cancers in women with BOTs compared with the general female Swedish population.

METHODS

An open cohort study (1995-2018) was conducted where a diagnosis of BOTs as well as subsequent or simultaneous cancer diagnoses were obtained from the Swedish Cancer Register and matched to the Total Population Register. Each woman with BOT was followed until non-ovarian cancer, death or emigration and could only be included once for the outcome. Standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) for specific non-ovarian cancers were analyzed.

RESULTS

The 4998 women with serous and mucinous BOTs were diagnosed during 1995-2018 with a mean age of 55.7 years (SD 16.0) at diagnosis. Compared with the general female population, women with BOTs had increased risks for non-ovarian cancer in colon (SIR = 2.5; 95% CI 2.0-3.1), rectum (SIR = 1.7; 95% CI 1.1-2.5), small intestine (SIR = 5.0; 95% CI 2.3-9.5), cervix (SIR = 2.5; 95% CI 1.4-4.2), endometrium (SIR = 2.4; 95% CI 1.9-3.1), pancreas (SIR = 2.3; 95% CI 1.4-3.5), upper aerodigestive tract (SIR = 2.2; 95% CI 1.2-3.8), lung (SIR = 1.8; 95% CI 1.4-2.3), kidney (SIR = 2.3; 95% CI 1.4-3.7) and bladder (SIR = 1.8; 95% CI 1.1-2.8). Among women with serous BOTs, the risk of thyroid gland cancer (SIR = 3.1; 95% CI 1.2-6.4) was also increased. Lung and pancreas cancer showed increased risks more than 1 year after a diagnosis of BOT.

CONCLUSIONS

This Swedish population-based study demonstrated an increased risk of multiple malignancies including lung and pancreatic cancers beyond the first year of diagnosis in patients with borderline ovarian tumors (BOTs), suggesting a potential shared etiology.

Incessant ovulation: a review of its importance in predicting cancer risk

Estrous cycles are recurring changes in therian mammals induced by estrogen, progesterone, and other hormones culminating in endometrial proliferation, ovulation, and implantation if fertilization occurred. In women, the estrous cycle is the menstrual cycle; but, unlike most mammals, the end of an infertile cycle is marked by endometrial sloughing and the start of another without an anestrous phase. Women stop cycling at menopause, while in most mammals, cycles continue until death. Epidemiologic studies identified menarche, menopause, births, lactation, and oral contraceptive (OC) use as key risk factors for ovarian, breast, and endometrial cancers. A composite variable was created to estimate the number of cycles not interrupted by events that stop ovulation. Captured by the phrase "incessant ovulation", repetitive cycles were first postulated to affect ovarian cancer risk and later extended to breast and endometrial cancers. These associations could be explained by cumulative effects of repetitive tissue changes within reproductive organs, immune consequences of repetitive ovulation through the glycoprotein mucin 1, and residual effects of past ovulations that enhance ovarian production of testosterone. The latter two pathways could affect the risk for cancers in other organs not considered "reproductive".

Prevention of Epithelial Ovarian Cancer

Given the challenges with achieving effective and durable treatment for epithelial ovarian cancer, primary prevention is highly desirable. Fortunately, decades of research have provided evidence for several strategies that can be deployed to optimize risk reduction. These include surgery, chemoprevention, and lifestyle factor modifications. These broad categories vary in terms of the magnitude of risk reduction possible, the possible short-term and long-term side effects, the degree of difficulty, and acceptability. Thus, the concept of a risk-based model to personalize preventive interventions is advocated to guide discussion between care providers and women at risk. For women with inherited major gene mutations that greatly increase risk of ovarian cancer, surgical approaches have favorable risk to benefit ratios. Chemoprevention and lifestyle factor modifications portend a lower degree of risk reduction but confer lower risk of undesirable side effects. Since complete prevention is not currently possible, better methods for early detection remain a high priority.

Epidemiology and risk factors for ovarian cancer

Ovarian cancer is a complex disease, mostly observed in postmenopausal women, and is associated with poor survival rates. It is the sixth most common cancer and the fifth most common cause of death due to cancer among women in developed countries. Thus, despite representing less than one third of all gynaecologic cancers, deaths due to ovarian cancer account for more than two thirds of deaths due to gynaecologic cancers. Its prevalence is higher in Western Europe and Northern America than Asia and Africa. In sub-Saharan Africa, there is a considerably lower prevalence of ovarian cancer than other parts of Africa. Ovarian cancer is multifaceted, involving many factors, complex biological processes and unpredictable consequences. Unlike other female cancers that have early warning symptoms, ovarian cancer's symptoms are non-specific. As a result, ovarian cancers are normally undetected until advanced stages (III or IV). The major risk factors for ovarian cancer include older age, genetics, family history, hormone replacement therapy, nulliparity, and dietary fat. Controversial factors include obesity, infertility, talc powder, radiation exposure, fertility medications and in vitro fertilization. The current review discusses the aetiology, epidemiology and risk factors for ovarian cancer. Nevertheless, identification of the main risk factors for ovarian cancer may increase the awareness among women of the general population. This should help to decrease the incidence rate of ovarian cancer and increase the five-year survival rate.

Risk of nonovarian cancer in a nationwide-based study of nearly 5000 women with borderline ovarian tumors in Denmark

Evidence regarding cancer risk after borderline ovarian tumors (BOTs) is limited. We conducted a nationwide cohort study examining the incidence of nonovarian cancers in women with serous or mucinous BOTs compared with the general female population with up to 41 years of follow-up. Through the nationwide Pathology Registry, we identified nearly 5000 women with BOTs (2506 serous and 2493 mucinous) in Denmark, 1978 to 2018. We computed standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) as relative risk estimates of specific nonovarian cancers. Compared with general female population rates, women with serous BOTs had increased rates of particularly malignant melanoma (SIR = 1.9; 95% CI: 1.3-2.6), thyroid cancer (SIR = 3.0; 95% CI: 1.4-5.4) and myeloid leukemia (SIR = 3.2; 95% CI: 1.5-5.8), and women with mucinous BOTs had elevated rates of lung cancer (SIR = 1.7; 95% CI: 1.3-2.1), pancreatic cancer (SIR = 1.9; 95% CI: 1.2-2.9) and myeloid leukemia (SIR = 2.3; 95% CI: 0.9-4.7). We found no convincing association with neither breast nor colorectal cancer in women with BOTs. This is the first large nationwide study showing that women with specific types of BOTs have increased risks of several nonovarian cancers, likely due to some shared risk factors or genetic characteristics.

Utility of Matrix Metalloproteinases in the Diagnosis, Monitoring and Prognosis of Ovarian Cancer Patients

Ovarian cancer is one of the most common gynecologic malignancies. It is characterized by a high mortality rate, which is mainly due to the asymptomatic course of the disease. In light of the high mortality rate and increasing morbidity, new diagnostic methods are being explored to enable earlier detection, better monitoring, and improved prognosis. Such diagnostic methods include the assessment of tumor markers in various biological samples. Among the markers currently being investigated, extracellular matrix metalloproteinases (MMPs) are of particular interest. The objective of this article was to compile the existing knowledge of MMPs in ovarian cancer patients and to describe their potential diagnostic utility. Additionally, this article provides an overview of the symptoms, complications, and risk factors associated with ovarian cancer and the role of MMPs in physiology and pathology. Preliminary results indicate that tissue expression and blood and body fluid levels of MMPs may be different in ovarian cancer patients than in healthy women. The expression and concentration of individual MMPs have been shown to be correlated with cancer stage and disease severity. In addition, the preliminary value of some of these enzymes in predicting prognosis is discussed. However, as the amount of data is limited, more studies are needed to fully evaluate the potential function of individual MMPs in ovarian cancer patients. Based on the knowledge gathered for this article, it seems that MMP-2, MMP-3, MMP-7, MMP-8, MMP-9, MMP-13, are tentatively the most useful. A thorough evaluation of their utility as modern biomarkers in ovarian cancer requires further investigation.

Evidence-based core information for health communication of tobacco control: The effect of smoking on risks of female disease

Objective

Cigarettes have become the the biggest killer of contemporary female's health and beauty. What kind of health information is suitable for the general public is an important issue to be discussed globally. The purpose of this study is to generate systematic, rigorous, public-demand-oriented and appropriate core information relevant to tobacco control based on the best available evidence, combined with audience preferences and pre-dissemination content review from multidisciplinary expertise in order to improve the effectiveness of health communication of tobacco control.

Methods

Relevant systematic reviews meta-analysis that reported smoking on risks of female disease were identified by searching PubMed, Embase, the Cochrane Library, Web of Science, Clinical Trials.gov, and the International Clinical Trial Registry Platform. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) process was applied to assess the evidence in order to make rigorous core information. The audience prevalence survey was conducted to ensure that core information was targeted and tailored. Finally, the expert assessment was used for a pre-dissemination content review and to evaluate whether the core information was appropriate or not.

Results

The final core information consisted of eight parts concerning the effects of smoking and female cardiovascular disease, diabetes, rheumatoid arthritis, respiratory disease, digestive system disease, mental disease, non-pregnant female reproductive system disease, as well as pregnant women and their fetuses. A total of 35 items of core information suitable for dissemination was included and the quality of evidence, the degree of public demand and the outcome of pre-dissemination content review were reported.

Conclusion

The core information related to female cardiovascular system diseases, as well as liver cancer and upper gastrointestinal cancer is the preferred content for health communication of tobacco control. The quality of evidence for core information related to pregnant women and their infants, as well as diseases of reproductive system, respiratory system, and diabetes needs to be improved to meet high public demand. The core information related to mental disease is more suitable for dissemination to patients with mental illness than to the general public. Besides, dissemination of core information should be individualized. Evidence-based Core Information for Health Communication of Tobacco Control would be helpful to provide evidence support for health communication related to tobacco control and enhance public health literacy for international communities that have high smoking prevalence and related disease burden.

Insights Into the Role of Epigenetic Factors Determining the Estrogen Response in Estrogen-Positive Ovarian Cancer and Prospects of Combining Epi-Drugs With Endocrine Therapy

Ovarian cancer is one of the most lethal malignancies. The population at the risk is continually on the rise due to the acquired drug resistance, high relapse rate, incomplete knowledge of the etiology, cross-talk with other gynecological malignancies, and diagnosis at an advanced stage. Most ovarian tumors are thought to arise in surface epithelium somehow in response to changes in the hormonal environment. Prolonged treatment with hormone replacement therapy (HRT) is also considered a contributing factor. Estrogens influence the etiology and progression of the endocrine/hormone-responsive cancers in a patient-specific manner. The concept of hormonal manipulations got attention during the last half of the 20th century when tamoxifen was approved by the FDA as the first selective estrogen receptor modulator (SERM). Endocrine therapy that has been found to be effective against breast cancer can be an option for ovarian cancer. It is now established that global changes in the epigenetic landscape are not only the hallmark of tumor development but also contribute to the development of resistance to hormone therapy. A set of functionally related genes involved in epigenetic reprogramming are controlled by specific transcription factors (TFs). Thus, the activities of TFs mediate important mechanisms through which epigenetic enzymes and co-factors modify chromatin for the worst outcome in a site-specific manner. Furthermore, the role of epigenetic aberrations involving histone modifications is established in ovarian cancer pathogenesis. This review aims to provide insights on the role of key epigenetic determinants of response as well as resistance to the hormone therapy, the current status of research along with its limitations, and future prospects of epigenetic agents as biomarkers in early diagnosis, prognosis, and personalized treatment strategies. Finally, the possibility of small phytoestrogenic molecules in combination with immunotherapy and epi-drugs targeting ovarian cancer has been discussed.

Germline BRCA variants, lifestyle and ovarian cancer survival

OBJECTIVE

Women with ovarian cancer who have a pathogenic germline variant in BRCA1 or BRCA2 (BRCA) have been shown to have better 5-year survival after diagnosis than women who are BRCA-wildtype (non-carriers). Modifiable lifestyle factors, including smoking, physical activity and body mass index (BMI) have previously been associated with ovarian cancer survival; however, it is unknown whether these associations differ by germline BRCA status.

METHODS

We investigated measures of lifestyle prior to diagnosis in two cohorts of Australian women with invasive epithelial ovarian cancer, using Cox proportional hazards regression to calculate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

In the combined studies (n = 1923), there was little association between physical activity, BMI or alcohol intake and survival, and no difference by BRCA status. However, the association between current smoking status before diagnosis and poorer survival was stronger for BRCA variant carriers (HR 1.98; 95% CI 1.20-3.27) than non-carriers (HR 1.18; 95% CI 0.96-1.46; p-interaction 0.02). We saw a similar differential association with smoking when we pooled results from two additional cohorts from the USA and UK (n = 2120). Combining the results from all four studies gave a pooled-HR of 1.94 (95% CI 1.28-2.94) for current smoking among BRCA variant carriers compared to 1.08 (0.90-1.29) for non-carriers.

CONCLUSIONS

Our results suggest that the adverse effect of smoking on survival may be stronger for women with a BRCA variant than those without. Thus, while smoking cessation may improve outcomes for all women with ovarian cancer, it might provide a greater benefit for BRCA variant carriers.

High Prediagnosis Inflammation-Related Risk Score Associated with Decreased Ovarian Cancer Survival

BACKGROUND

There is suggestive evidence that inflammation is related to ovarian cancer survival. However, more research is needed to identify inflammation-related factors that are associated with ovarian cancer survival and to determine their combined effects.

METHODS

This analysis used pooled data on 8,147 women with invasive epithelial ovarian cancer from the Ovarian Cancer Association Consortium. The prediagnosis inflammation-related exposures of interest included alcohol use; aspirin use; other nonsteroidal anti-inflammatory drug use; body mass index; environmental tobacco smoke exposure; history of pelvic inflammatory disease, polycystic ovarian syndrome, and endometriosis; menopausal hormone therapy use; physical inactivity; smoking status; and talc use. Using Cox proportional hazards models, the relationship between each exposure and survival was assessed in 50% of the data. A weighted inflammation-related risk score (IRRS) was developed, and its association with survival was assessed using Cox proportional hazards models in the remaining 50% of the data.

RESULTS

There was a statistically significant trend of increasing risk of death per quartile of the IRRS [HR = 1.09; 95% confidence interval (CI), 1.03-1.14]. Women in the upper quartile of the IRRS had a 31% higher death rate compared with the lowest quartile (95% CI, 1.11-1.54).

CONCLUSIONS

A higher prediagnosis IRRS was associated with an increased mortality risk after an ovarian cancer diagnosis. Further investigation is warranted to evaluate whether postdiagnosis exposures are also associated with survival.

IMPACT

Given that pre- and postdiagnosis exposures are often correlated and many are modifiable, our study results can ultimately motivate the development of behavioral recommendations to enhance survival among patients with ovarian cancer.

Network Medicine-Based Analysis of Association Between Gynecological Cancers and Metabolic and Hormonal Disorders

Different metabolic and hormonal disorders like type 2 diabetes mellitus (T2DM), obesity, and polycystic ovary syndrome (PCOS) have tangible socio-economic impact. Prevalence of these metabolic and hormonal disorders is steadily increasing among women. There are clinical evidences that these physiological conditions are related to the manifestation of different gynecological cancers and their poor prognosis. The relationship between metabolic and hormonal disorders with gynecological cancers is quite complex. The need for gene level association study is extremely important to find markers and predicting risk factors. In the current work, we have selected metabolic disorders like T2DM and obesity, hormonal disorder PCOS, and 4 different gynecological cancers like endometrial, uterine, cervical, and triple negative breast cancer (TNBC). The gene list was downloaded from DisGeNET database (v 6.0). The protein interaction network was constructed using HIPPIE (v 2.2) and shared proteins were identified. Molecular comorbidity index and Jaccard coefficient (degree of similarity) between the diseases were determined. Pathway enrichment analysis was done using ReactomePA and significant modules (clusters in a network) of the constructed network was analyzed by MCODE plugin of Cytoscape. The comorbid conditions like PCOS-obesity found to increase the risk factor of ovarian and triple negative breast cancers whereas PCOS alone has highest contribution to the endometrial cancer. Different gynecological cancers were found to be differentially related to the metabolic/hormonal disorders and comorbid condition.

A multidisciplinary approach remains the best strategy to improve and strengthen the management of ovarian cancer (Review)

Ovarian cancer represents one of the most aggressive female tumors worldwide. Over the decades, the therapeutic options for the treatment of ovarian cancer have been improved significantly through the advancement of surgical techniques as well as the availability of novel effective drugs able to extend the life expectancy of patients. However, due to its clinical, biological and molecular complexity, ovarian cancer is still considered one of the most difficult tumors to manage. In this context, several studies have highlighted how a multidisciplinary approach to this pathology improves the prognosis and survival of patients with ovarian cancer. On these bases, the aim of the present review is to present recent advantages in the diagnosis, staging and treatment of ovarian cancer highlighting the benefits of a patient‑centered care approach and on the importance of a multidisciplinary team for the management of ovarian cancer.

Male origin microchimerism and ovarian cancer

BACKGROUND

Reduced risk of ovarian cancer is commonly ascribed to reduced exposure to endogenous hormones during pregnancy, using oral contraceptives or not using hormone replacement therapy. However, exposure to hormones alone account for less than half of all cases. Many women carry small amounts of male cells-known as male origin microchimerism-in their circulation and remarkable impacts of these cells on women's health are being published. Here, we pursue the possibility that male origin microchimerism has a role in reducing ovarian cancer risk.

METHODS

We conducted a prospective case-cohort study using blood samples and questionnaire data from 700 women participating in the Danish Diet, Cancer, and Health cohort. Blood samples were analysed for Y chromosome presence as a marker of male microchimerism. We evaluated the association between male microchimerism and ovarian cancer, using weighted Cox regression models reporting hazard ratios (HRs) and corresponding 95% confidence intervals (CIs).

RESULTS

Male microchimerism was detected in 46% of cases and 65.9% of controls. Women testing positive for male microchimerism had a reduced hazard rate of ovarian cancer compared with women testing negative (HR = 0.44, 95% CI: 0.29-0.68). We found no evidence of interaction with measures of hormonal exposures (P = 0.50).

CONCLUSIONS

For the first time we report that women who test positive for male microchimerism in their circulation have reduced rates of ovarian cancer compared with women who test negative. Although the underlying mechanisms are presently unknown, we believe male microchimerism is potent in preventing ovarian cancer.

Cigarette Smoking and Estrogen-Related Cancer

Cigarette smoking is a known cause of many cancers, yet epidemiologic studies have found protective associations with the risk of four "estrogen-related" malignancies: endometrial cancer, endometrioid and clear cell ovarian cancers, and thyroid cancer. This review considers epidemiologic and biological aspects of these associations, focusing particularly on estrogen signaling, and contrasts them with those for breast cancer, another estrogen-related malignancy. The observational findings regarding the inverse associations are consistent and remain after adjustment for possible confounding factors. In general, women who smoke do not have lower circulating estrogen levels than nonsmokers, eliminating one possible explanation for reduced risks of these malignancies. For endometrial and endometrioid ovarian cancer, the negative associations could plausibly be explained by interference with signaling through the estrogen receptor α. However, this is unlikely to explain the lower risks of thyroid and clear cell ovarian cancers. For thyroid cancer, an anti-inflammatory effect of nicotine and reduced TSH levels from smoking have been proposed explanations for the inverse association, but both lack convincing evidence. While the overall impact of cigarette smoking is overwhelmingly negative, protective associations such as those discussed here can provide potential clues to disease etiology, treatment, and prevention.

Circulating Biomarkers of Inflammation and Ovarian Cancer Risk in the Nurses' Health Studies

BACKGROUND

Chronic inflammation is a well-established mechanism of ovarian carcinogenesis; however, the specific immunogenic processes influencing ovarian tumor development remain unclear. In a case-control study nested within the Nurses' Health Study (NHS) and the NHSII, we examined the association between six inflammatory chemokines and cytokines [B-cell activating factor (BAFF), C-X-C motif chemokine ligand 13 (CXCL13), IL8, soluble(s)IL2-receptor-α(Rα), sIL6Rα] and epithelial ovarian cancer risk.

METHODS

Among 299 epithelial ovarian cancer cases and 334 matched controls, six inflammatory biomarkers were measured in plasma collected 1-24 years before diagnosis or index date using two custom multiplex Luminex panels. ORs and 95% confidence intervals (CI) were estimated for the association between each biomarker and risk using multivariable conditional logistic regression with adjustment for relevant confounders. We additionally assessed heterogeneity in the risk associations by histotype [high-grade serous carcinoma (HGSC) vs. non-HGSC], body mass index, smoking status, menopausal status, and aspirin use.

RESULTS

Women with the highest versus lowest quartile (Q) levels of CXCL13 had a 72% increased ovarian cancer risk (OR = 1.72; 95% CI = 1.04-2.83; P _trend = 0.007). The positive association with CXCL13 was stronger in magnitude for non-HGSC, overweight or obese women, and postmenopausal women, although only menopausal status demonstrated statistically significant heterogeneity (P _interaction = 0.04). The remaining biomarkers were not associated with risk.

CONCLUSIONS

This first evidence that prediagnostic CXCL13, a B-cell chemoattractant, is associated with an increased risk of epithelial ovarian cancer expands current understanding of the role of inflammation in ovarian carcinogenesis.

IMPACT

CXCL13 may represent a novel biomarker for ovarian cancer.

Translational Theragnosis of Ovarian Cancer: where do we stand?

BACKGROUND

Ovarian cancer is the second most common gynecologic malignancy, accounting for approximately 220,000 deaths annually worldwide. Despite radical surgery and initial high response rates to platinum- and taxane-based chemotherapy, most patients experience a relapse, with a median progression-free survival of only 18 months. Overall survival is approximately 30% at 5 years from the diagnosis. In comparison, patients out from breast cancer are more than 80 % after ten years from the disease discovery. In spite of a large number of published fundamental and applied research, and clinical trials, novel therapies are urgently needed to improve outcomes of the ovarian cancer. The success of new drugs development in ovarian cancer will strongly depend on both fully genomic disease characterization and, then, availability of biomarkers able to identify women likely to benefit from a given new therapy.

METHODS

In this review, the focus is given to describe how complex is the diseases under the simple name of ovarian cancer, in terms of cell tumor types, histotypes, subtypes, and specific gene mutation or differently expressed in the tumor with respect the healthy ovary. The first- and second-line pharmacological treatment clinically used over the last fifty years are also described. Noteworthy achievements in vitro and in vivo tested new drugs are also summarized. Recent literature related to up to date ovarian cancer knowledge, its detection by biomarkers and chemotherapy was searched from several articles on Pubmed, Google Scholar, MEDLINE and various Governmental Agencies till April 2019.

RESULTS

The papers referenced by this review allow a deep analysis of status of the art in the classification of the several types of ovarian cancer, the present knowledge of diagnosis based on biomarkers and imaging techniques, and the therapies developed over the past five decades.

CONCLUSION

This review aims at stimulating more multi-disciplinary efforts to identify a panel of novel and more specific biomarkers to be used to screen patients for a very early diagnosis, to have prognosis and therapy efficacy indications. The desired final goal would be to have available tools allowing to reduce the recurrence rate, increase both the disease progression free interval and of course the overall survival at five years from the diagnosis that today is still very low.

Racial Differences in Population Attributable Risk for Epithelial Ovarian Cancer in the OCWAA Consortium

BACKGROUND

The causes of racial disparities in epithelial ovarian cancer (EOC) incidence remain unclear. Differences in the prevalence of ovarian cancer risk factors may explain disparities in EOC incidence among African American (AA) and White women.

METHODS

We used data from 4 case-control studies and 3 case-control studies nested within prospective cohorts in the Ovarian Cancer in Women of African Ancestry Consortium to estimate race-specific associations of 10 known or suspected EOC risk factors using logistic regression. Using the Bruzzi method, race-specific population attributable risks (PAR) were estimated for each risk factor individually and collectively, including groupings of exposures (reproductive factors and modifiable factors). All statistical tests were 2-sided.

RESULTS

Among 3244 White EOC cases and 9638 controls and 1052 AA EOC cases and 2410 controls, AA women had a statistically significantly higher PAR (false discovery rate [FDR] P < .001) for first-degree family history of breast cancer (PAR = 10.1%, 95% confidence interval [CI] = 6.5% to 13.7%) compared with White women (PAR = 2.6%, 95% CI = 0.8% to 4.4%). After multiple test correction, AA women had a higher PAR than White women when evaluating all risk factors collectively (PAR = 61.6%, 95% CI = 48.6% to 71.3% vs PAR = 43.0%, 95% CI = 32.8% to 51.4%, respectively; FDR P = .06) and for modifiable exposures, including body mass index, oral contraceptives, aspirin, and body powder (PAR = 36.0%, 95% CI = 21.0% to 48.8% vs PAR = 13.8%, 95% CI = 4.5% to 21.8%, respectively; FDR P = .04).

CONCLUSIONS

Collectively, the selected risk factors accounted for slightly more of the risk among AA than White women, and interventions to reduce EOC incidence that are focused on multiple modifiable risk factors may be slightly more beneficial to AA women than White women at risk for EOC.

Long non-coding RNAs in ovarian cancer: expression profile and functional spectrum

Long non-coding RNAs (lncRNAs), initially recognized as byproducts of the transcription process, have been proven to play crucial modulatory roles in preserving overall homoeostasis of cells and tissues. Furthermore, aberrant levels of these transcripts have been shown to contribute many diseases, including cancer. Among these, many aspects of ovarian cancer biology have been found to be regulated by lncRNAs, including cancer initiation, progression and dissemination. In this review, we summarize recent studies to highlight the various roles of lncRNAs in ovary in normal and pathological conditions, immune system, diagnosis, prognosis, and therapy. We address lncRNAs that have been extensively studied in ovarian cancer and their contribution to cellular dynamics.

Morphological and molecular heterogeneity of epithelial ovarian cancer: Therapeutic implications

Ovarian epithelial cancer (OEC) is the most lethal gynecologic malignancy. Despite current chemotherapeutic and surgical options, this high lethality can be attributed to multiple factors, including late-stage presentation. In order to optimize OEC treatment, it is important to highlight that it is composed of five main subtypes: high-grade serous ovarian carcinoma (HGSOC), low-grade serous ovarian carcinoma (LGSOC), endometrioid ovarian carcinoma (EOC), ovarian clear cell carcinoma (CCOC), and mucinous ovarian carcinoma (MOC). These subtypes differ in their precursor lesions, as well as in epidemiological, morphological, molecular and clinical features. OEC is one of the tumours in which most pathogenic germline mutations have been identified. Accordingly, up to 20% OC show alterations in BRCA1/2 genes, and also, although with a lower frequency, in other low penetrance genes associated with homologous recombination deficiency (HRD), mismatch repair genes (Lynch syndrome) and TP53. The most important prognostic factor is the 2014 FIGO staging, while older age is also associated with worse survival. HGSOC in all stages and CCC and MOC in advanced stages have the worse prognosis among histological types. Molecular markers have emerged as prognostic factors, particularly mutations in BRCA1/2, which are associated with a better outcome. Regarding treatment, whereas a proportion of HGSOC is sensible to platinum-based treatment and PARP inhibitors due to HRD, the rest of the histological types are relatively chemoresistant. New treatments based in specific molecular alterations are being tested in different histological types. In addition, immunotherapy could be an option, especially for EOC carrying mismatch repair deficiency or POLE mutations.

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The five different histological types have different precursor lesions and epidemiological, morphological, genetic, epigenetic and clinical features.

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Histological type is an important prognostic factor.

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Drugs targeting homologous recombination deficiency have been approved for treatment.

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The use of immunotherapy is limited due to lack of predictive biomarkers

Systematic review and meta-analysis of studies assessing the relationship between statin use and risk of ovarian cancer

PURPOSE

The link between lipid-stabilizing medications and epithelial ovarian carcinogenesis is incompletely understood. Statins may reduce ovarian cancer risk, but results are inconclusive.

METHODS

We conducted a systematic review and meta-analysis of studies reporting associations between statin use and ovarian cancer risk in PubMed. Summary risk ratios (RRs) and confidence intervals (CIs) were calculated. Subgroup analyses by cancer histotype, statin class (lipo- or hydrophilic) and duration of statin use were conducted. Use of individual statins in populations was assessed to determine population-specific differences in statin types.

RESULTS

Nine studies with 435,237 total women were included (1 randomized controlled trial (RCT); 4 prospective; 4 case-control). Statin use was associated with a reduced risk of ovarian cancer (RR 0.87, 95% CI 0.74-1.03) and risk was significantly reduced in populations with low pravastatin use (RR 0.83, 95% CI 0.70-0.99). Risk estimates varied by statin class (3 studies; lipophilic: RR 0.88, 95% CI 0.69-1.12; hydrophilic: RR 1.06, 95% CI 0.72-1.57) and cancer histotype (3 studies; serous: RR 0.95, 95% CI 0.69-1.30; clear cell: RR 1.17, 95% CI 0.74-1.86). Long-term use was associated with a reduced risk of ovarian cancer (RR 0.77, 95% CI 0.54-1.10) that further reduced when pravastatin use was low (RR 0.68, 95% CI 0.46-1.01). Between-study heterogeneity was high overall and in subgroups (I² > 60%).

CONCLUSION

Statins may be associated with a reduced risk of ovarian cancer, but the effect likely differs by individual statin, duration of use and cancer histotype. Additional well-powered studies are needed to elucidate important subgroup effects.

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.

Ovarian cancer screening: Current status and future directions

Ovarian cancer is the third most common gynaecological malignancy and the most lethal worldwide. Most patients are diagnosed with advanced disease which carries significant mortality. Improvements in treatment have only resulted in modest increases in survival. This has driven efforts to reduce mortality through screening. Multimodal ovarian cancer screening using a longitudinal CA125 algorithm has resulted in diagnosis at an earlier stage, both in average and high risk women in two large UK trials. However, no randomised controlled trial has demonstrated a definitive mortality benefit. Extended follow up is underway in the largest trial to date, UKCTOCS, to explore the delayed reduction in mortality that was noted. Meanwhile, screening is not currently recommended in the general population Some countries offer surveillance of high risk women. Novel screening modalities and longitudinal biomarker algorithms offer potential improvements to future screening strategies as does the development of better risk stratification tools.

[Borderline Ovarian Tumours: CNGOF Guidelines for Clinical Practice - Epidemiological Aspects and Risk Factors]

The incidence (rate/100,000) of BOT gradually increases with age from 15-19 years of age and peaks at nearly 4.5 cases/100,000 for the 55-59 year age group (NP3). In the presence of a benign ovarian mass, the standardized risk ratio of serous and mucinous BOT is 1.69, (95% CI 1.39-2.03) and 1.75, (95% CI 1.45-2.10), respectively (NP2). At diagnosis, a median age of diagnosis of OFA is 46 years, unilateral forms (79.7% of cases) are predominant compared to cancers (45.3%) (<0.001) and FIGO I stages represent nearly 63.7% of cases (NP3). The 5-year survival rates for FIGO I, II, III, IV stages are: 99.7% (95% CI: 96.2-100%), 99.6% (95% CI: 92.6-100%), 95.3% (95% CI: 91.8-97.4%), 77.1% (95% CI: 58.0-88.3%), respectively (NP3). Survivors at 5 years for serous and mucinous tumours are 99.7% (95% CI: 99.2-99.9%), 98.5% (95% CI: 96.9-99.3%), respectively (NP3). An epidemiological association exists between personal BOT risk and: (1) a familial history of BOT/certain cancers (pancreas, lung, bone, leukemia) (NP3), (2) a personal history of benign ovarian cyst (NP2), (3) a personal history of pelvic inflammatory disease (IGH), (4) the use of intrauterine device levonorgestrel (NP3), (5) the use of oral contraceptive pills (NP3), (6) multiparity (NP3), (7) hormone replacement therapy (NP3), (8) high consumption of coumestrol (NP4), (9) medical treatment of infertility with progesterone (NP3), (10) non-steroidal anti-inflammatory drug (NSAID). An epidemiological association exists between previous/actual tabacco consumption and the risk of mucinous ovarian BOT (NP2). Relative risk (RR) varies between 2.2 and 2.7, however the relationship is not necessarily a causal one. An epidemiological association exists between overweight/obesity and the risk of serous BOT (NP2). RR varies between 1.2 to 1.8. The high Vitamin D was inversely associated to the risk of serous BOT (NP4). The risk of mucinous BOT was lowered with paracetamol use (OR=0.77; 95% CI: 0.60-0.98) (NP3). However, the relationship between these factors and BOT is not necessarily a causal one and no screening modality can be proposed in the general population (gradeC).

High Levels of C-Reactive Protein Are Associated with an Increased Risk of Ovarian Cancer: Results from the Ovarian Cancer Cohort Consortium

Growing epidemiologic evidence supports chronic inflammation as a mechanism of ovarian carcinogenesis. An association between a circulating marker of inflammation, C-reactive protein (CRP), and ovarian cancer risk has been consistently observed, yet, potential heterogeneity of this association by tumor and patient characteristics has not been adequately explored. In this study, we pooled data from case-control studies nested within six cohorts in the Ovarian Cancer Cohort Consortium (OC3) to examine the association between CRP and epithelial ovarian cancer risk overall, by histologic subtype and by participant characteristics. CRP concentrations were measured from prediagnosis serum or plasma in 1,091 cases and 1,951 controls. Multivariable conditional logistic regression was used to estimate ORs and 95% confidence intervals (CI). When CRP was evaluated using tertiles, no associations with ovarian cancer risk were observed. A 67% increased ovarian cancer risk was found for women with CRP concentrations >10 mg/L compared with <1 mg/L (OR = 1.67; 95% CI = 1.12-2.48). A CRP concentration >10 mg/L was positively associated with risk of mucinous (OR = 9.67; 95% CI = 1.10-84.80) and endometrioid carcinoma (OR = 3.41; 95% CI = 1.07-10.92), and suggestively positive, although not statistically significant, for serous (OR = 1.43; 95% CI = 0.82-2.49) and clear cell carcinoma (OR = 2.05; 95% CI = 0.36-11.57; P heterogeneity = 0.20). Heterogeneity was observed with oral contraceptive use (P interaction = 0.03), where the increased risk was present only among ever users (OR = 3.24; 95% CI = 1.62-6.47). This study adds to the existing evidence that CRP plays a role in ovarian carcinogenesis and suggests that inflammation may be particularly implicated in the etiology of endometrioid and mucinous carcinoma. SIGNIFICANCE: C-reactive protein is involved in ovarian carcinogenesis, and chronic inflammation may be particularly implicated in the etiology of mucinous and endometrioid carcinomas.

Ovarian Cancer in Women of African Ancestry (OCWAA) consortium: a resource of harmonized data from eight epidemiologic studies of African American and white women

PURPOSE

Although the incidence rate of epithelial ovarian cancer (EOC) is somewhat lower in African American (AA) than white women, survival is worse. The Ovarian Cancer in Women of African Ancestry (OCWAA) consortium will overcome small, study-specific sample sizes to better understand racial differences in EOC risk and outcomes.

METHODS

We harmonized risk factors and prognostic characteristics from eight U.S.

STUDIES

the North Carolina Ovarian Cancer Study (NCOCS), the Los Angeles County Ovarian Cancer Study (LACOCS), the African American Cancer Epidemiology Study (AACES), the Cook County Case-Control Study (CCCCS), the Black Women's Health Study (BWHS), the Women's Health Initiative (WHI), the Multiethnic Cohort Study (MEC), and the Southern Community Cohort Study (SCCS).

RESULTS

Determinants of disparities for risk and survival in 1,146 AA EOC cases and 2,922 AA controls will be compared to 3,368 white EOC cases and 10,270 white controls. Analyses include estimation of population-attributable risk percent (PAR%) by race.

CONCLUSION

OCWAA is uniquely positioned to study the epidemiology of EOC in AA women compared with white women to address disparities. Studies of EOC have been underpowered to address factors that may explain AA-white differences in the incidence and survival. OCWAA promises to provide novel insight into disparities in ovarian cancer.

Appraising the role of previously reported risk factors in epithelial ovarian cancer risk: A Mendelian randomization analysis

BACKGROUND

Various risk factors have been associated with epithelial ovarian cancer risk in observational epidemiological studies. However, the causal nature of the risk factors reported, and thus their suitability as effective intervention targets, is unclear given the susceptibility of conventional observational designs to residual confounding and reverse causation. Mendelian randomization (MR) uses genetic variants as proxies for risk factors to strengthen causal inference in observational studies. We used MR to evaluate the association of 12 previously reported risk factors (reproductive, anthropometric, clinical, lifestyle, and molecular factors) with risk of invasive epithelial ovarian cancer, invasive epithelial ovarian cancer histotypes, and low malignant potential tumours.

METHODS AND FINDINGS

Genetic instruments to proxy 12 risk factors were constructed by identifying single nucleotide polymorphisms (SNPs) that were robustly (P < 5 × 10-8) and independently associated with each respective risk factor in previously reported genome-wide association studies. These risk factors included genetic liability to 3 factors (endometriosis, polycystic ovary syndrome, type 2 diabetes) scaled to reflect a 50% higher odds liability to disease. We obtained summary statistics for the association of these SNPs with risk of overall and histotype-specific invasive epithelial ovarian cancer (22,406 cases; 40,941 controls) and low malignant potential tumours (3,103 cases; 40,941 controls) from the Ovarian Cancer Association Consortium (OCAC). The OCAC dataset comprises 63 genotyping project/case-control sets with participants of European ancestry recruited from 14 countries (US, Australia, Belarus, Germany, Belgium, Denmark, Finland, Norway, Canada, Poland, UK, Spain, Netherlands, and Sweden). SNPs were combined into multi-allelic inverse-variance-weighted fixed or random effects models to generate effect estimates and 95% confidence intervals (CIs). Three complementary sensitivity analyses were performed to examine violations of MR assumptions: MR-Egger regression and weighted median and mode estimators. A Bonferroni-corrected P value threshold was used to establish strong evidence (P < 0.0042) and suggestive evidence (0.0042 < P < 0.05) for associations. In MR analyses, there was strong or suggestive evidence that 2 of the 12 risk factors were associated with invasive epithelial ovarian cancer and 8 of the 12 were associated with 1 or more invasive epithelial ovarian cancer histotypes. There was strong evidence that genetic liability to endometriosis was associated with an increased risk of invasive epithelial ovarian cancer (odds ratio [OR] per 50% higher odds liability: 1.10, 95% CI 1.06-1.15; P = 6.94 × 10-7) and suggestive evidence that lifetime smoking exposure was associated with an increased risk of invasive epithelial ovarian cancer (OR per unit increase in smoking score: 1.36, 95% CI 1.04-1.78; P = 0.02). In analyses examining histotypes and low malignant potential tumours, the strongest associations found were between height and clear cell carcinoma (OR per SD increase: 1.36, 95% CI 1.15-1.61; P = 0.0003); age at natural menopause and endometrioid carcinoma (OR per year later onset: 1.09, 95% CI 1.02-1.16; P = 0.007); and genetic liability to polycystic ovary syndrome and endometrioid carcinoma (OR per 50% higher odds liability: 0.89, 95% CI 0.82-0.96; P = 0.002). There was little evidence for an association of genetic liability to type 2 diabetes, parity, or circulating levels of 25-hydroxyvitamin D and sex hormone binding globulin with ovarian cancer or its subtypes. The primary limitations of this analysis include the modest statistical power for analyses of risk factors in relation to some less common ovarian cancer histotypes (low grade serous, mucinous, and clear cell carcinomas), the inability to directly examine the association of some ovarian cancer risk factors that did not have robust genetic variants available to serve as proxies (e.g., oral contraceptive use, hormone replacement therapy), and the assumption of linear relationships between risk factors and ovarian cancer risk.

CONCLUSIONS

Our comprehensive examination of possible aetiological drivers of ovarian carcinogenesis using germline genetic variants to proxy risk factors supports a role for few of these factors in invasive epithelial ovarian cancer overall and suggests distinct aetiologies across histotypes. The identification of novel risk factors remains an important priority for the prevention of epithelial ovarian cancer.

Association between Cigarette Smoking and Histotype-Specific Epithelial Ovarian Cancer: A Review of Epidemiologic Studies

Many studies have demonstrated that smoking can influence ovarian cancer risk and survival; however, the number of studies investigating this relationship according to histologic subtypes is limited. We conducted a review of epidemiologic research that assessed the role of smoking on ovarian cancer risk and survival after diagnosis, specifically capturing studies that discerned between various histologic subtypes of this disease. In the majority of studies, current smoking was associated with increased risk of mucinous cancer. There was also evidence of a decreased risk of clear cell and endometrioid histotypes. No significant association was observed between cigarette smoking and serous cancer. In the studies investigating the relationship between smoking and survival, all the studies reported an increased risk of mortality associated with smoking. Smoking appeared to be a risk factor for both ovarian cancer risk and mortality. Future studies need to investigate further a potential link between smoking and ovarian cancer by having a better assessment of exposure to smoking and having a larger number of participants with the ability to detect associations within rare histotypes.

Dose-risk relationships between cigarette smoking and ovarian cancer histotypes: a comprehensive meta-analysis

PURPOSE

Although smoking has not been associated with overall ovarian cancer risk, a different impact on various histotypes has been reported. Our aim is to provide an accurate, up-to-date estimate of the dose-risk relationships between cigarette smoking and epithelial ovarian cancer, overall and by histotypes.

METHODS

Using an innovative approach for the identification of original study publications, we conducted a systematic review and meta-analysis of epidemiological studies published on the topic until September 2018. Summary relative risks (RR) for cigarette smoking were estimated using random-effects models; dose-risk relationships were evaluated using one-stage random-effects models with restricted cubic splines.

RESULTS

Thirty-seven studies were considered in the meta-analysis. The summary RRs for current versus never smokers were 1.05 (95% confidence interval CI 0.95-1.16) for overall ovarian cancer, 1.78 (95% CI 1.52-2.07) for mucinous, 0.77 (95% CI 0.65-0.93) for clear cell, 0.81 (95% CI 0.73-0.91) for endometrioid, and 1.05 (95% CI 0.94; 1.17) for serous cancer. The risk of borderline mucinous (RR 2.09) and serous (RR 1.16) tumors was higher than for invasive cancers (RR 1.44 and 0.95, respectively). For mucinous cancer, risk was noticeably higher with smoking intensity and duration (RR 2.35 for 20 cigarettes/day, and 2.11 for 20 years of smoking). A non-significant linear relation was found with smoking intensity, duration, and time since quitting for overall ovarian cancer and other histotypes.

CONCLUSIONS

This uniquely large and comprehensive meta-analysis confirms that although cigarette smoking does not appear to be a risk factor for ovarian cancer, and it is even slightly protective for some rare histotypes, there is a strong dose-risk relationship with mucinous ovarian cancer.

Unraveling a difficult diagnosis: the tricks for early recognition of ovarian cancer

Epithelial ovarian cancer (EOC) is the predominant type of ovarian cancer (OC). The 5-year survival of patients has improved over the last three decades, although the overall cure rate of OC if about 30%. Despite high response rates after initial chemotherapy, most patients with advanced ovarian cancer ultimately develop the recurrent disease because of resistance to chemotherapy. A proper early diagnosis and treatment of patients with ovarian cancer are urgently needed. Nowadays the diagnosis is performed by means of clinical symptoms and signs, often indicators of a disease already at an advanced stage, tumor markers (CA125 and HE4), transvaginal ultrasonography and imaging, very useful in distinguishing adnexal masses. Understand the nature of an adnexal mass is the primary point to begin the diagnosis of OC. Validated different model to approach and characterize adnexal pathology preoperatively are described, such as the International Ovarian Tumor Analysis (IOTA) and the Assessment of Different NEoplasias in the AdneXa (ADNEX) model. New tumor markers, such as PRSS8, FOLR1, KLK6/7, GSTT1, and miRNAs, are getting ahead and are worth noting for early detection of ovarian cancer. Despite the development of numerous ultrasound models for the diagnosis of adnexal masses and the analysis of different tumor markers, the early diagnosis of ovarian cancer is still difficult to practice. Moreover, identifying genetic risk alleles, such as germline BRCA1 and BRCA2 mutations, for ovarian cancer has had a significant impact on disease prevention strategies.

Evaluation of vitamin D biosynthesis and pathway target genes reveals UGT2A1/2 and EGFR polymorphisms associated with epithelial ovarian cancer in African American Women

An association between genetic variants in the vitamin D receptor (VDR) gene and epithelial ovarian cancer (EOC) was previously reported in women of African ancestry (AA). We sought to examine associations between genetic variants in VDR and additional genes from vitamin D biosynthesis and pathway targets (EGFR, UGT1A, UGT2A1/2, UGT2B, CYP3A4/5, CYP2R1, CYP27B1, CYP24A1, CYP11A1, and GC). Genotyping was performed using the custom-designed 533,631 SNP Illumina OncoArray with imputation to the 1,000 Genomes Phase 3 v5 reference set in 755 EOC cases, including 537 high-grade serous (HGSOC), and 1,235 controls. All subjects are of African ancestry (AA). Logistic regression was performed to estimate odds ratios (OR) and 95% confidence intervals (CI). We further evaluated statistical significance of selected SNPs using the Bayesian False Discovery Probability (BFDP). A significant association with EOC was identified in the UGT2A1/2 region for the SNP rs10017134 (per allele OR = 1.4, 95% CI = 1.2-1.7, P = 1.2 × 10-6 , BFDP = 0.02); and an association with HGSOC was identified in the EGFR region for the SNP rs114972508 (per allele OR = 2.3, 95% CI = 1.6-3.4, P = 1.6 × 10-5 , BFDP = 0.29) and in the UGT2A1/2 region again for rs1017134 (per allele OR = 1.4, 95% CI = 1.2-1.7, P = 2.3 × 10-5 , BFDP = 0.23). Genetic variants in the EGFR and UGT2A1/2 may increase susceptibility of EOC in AA women. Future studies to validate these findings are warranted. Alterations in EGFR and UGT2A1/2 could perturb enzyme efficacy, proliferation in ovaries, impact and mark susceptibility to EOC.

Joint exposure to smoking, excessive weight, and physical inactivity and survival of ovarian cancer patients, evidence from the Ovarian Cancer Association Consortium

PURPOSE

Previous epidemiologic studies have shown that smoking, obesity, and physical inactivity are associated with poor survival following a diagnosis of ovarian cancer. Yet, the combined relationship of these unfavorable lifestyle factors on ovarian cancer survival has not been sufficiently investigated.

METHODS

Using data pooled from 13 studies, we examined the associations between combined exposures to smoking, overweight/obesity weight, and physical inactivity and overall survival (OS) as well as progression-free survival (PFS) among women diagnosed with invasive epithelial ovarian carcinoma (n = 7,022). Using age- and stage-adjusted Cox proportional hazards regression models, we estimated hazard ratios (HRs) and 95% confidence intervals (CIs) associated with joint exposure to these factors.

RESULTS

Combined exposure to current smoking, overweight/obesity, and physical inactivity prior to diagnosis was associated with a significantly increased risk of mortality compared to women who never smoked, had normal body mass index (BMI), and were physically active (HR = 1.37; 95% CI 1.10-1.70). The association for a joint exposure to these factors exceeded that of each exposure individually. In fact, exposure to both current smoking and overweight/obesity, and current smoking and physical inactivity was also associated with increased risk of death (HR = 1.28; 95% CI 1.08-1.52, and HR = 1.26; 95% CI 1.04-1.54, respectively). The associations were of a similar magnitude when former smoking was assessed in combination with the other exposures and when excessive weight was limited to obesity only. No significant associations were observed between joint exposure to any of these factors and PFS.

CONCLUSIONS

Joint exposure to smoking, excessive weight, and physical inactivity may negatively impact survival of ovarian cancer patients. These results suggest the importance of examining the combined effect of lifestyle factors on ovarian cancer patients' survival.

Trends and characteristics of epithelial ovarian cancer in Japan between 2002 and 2015: A JSGO-JSOG joint study

OBJECTIVE

To examine the trends of epithelial ovarian cancer histologic subtypes in Japan.

METHODS

A nationwide retrospective registry study was performed between 2002 and 2015 (Japan cohort, n = 48,640). Trends were also examined in The Surveillance, Epidemiology, and End Results Program (US cohort, n = 49,936). Time-specific proportional changes of four major histological subtypes (serous, clear cell, endometrioid, and mucinous) were examined.

RESULTS

The Japan cohort had more stage I disease (44.1% versus 24.9%) and less stage IV disease (10.0% versus 23.1%) than the US cohort (P < 0.001). The Japan cohort had more non-serous histology, particularly clear cell carcinoma (26.9% versus 8.4%), than the US cohort (P < 0.001). In the Japan cohort, proportion of clear cell carcinoma increased significantly from 23.4% to 29.1% between 2002 and 2010 (P < 0.001). Among stage I disease, clear cell carcinoma increased significantly in the Japan cohort from 32.9% to 40.3% between 2002 and 2015 (P < 0.001), whereas mucinous carcinoma increased significantly in the US cohort from 15.0% to 24.8% (P = 0.01). In 2015, clear cell carcinoma was most common among women aged <50 years from the Japan cohort (30.2%) versus serous carcinoma in the US cohort (50.8%). In the Japan cohort, the peak age was 75 years for serous, 57 for clear cell, and 45 for endometrioid carcinoma (P < 0.001). Mucinous carcinoma decreased until 43 years and increased again after age 73 years (P < 0.001).

CONCLUSION

Characteristics of epithelial ovarian cancer in Japan are largely different compared to the US. In Japan, clear cell carcinoma has increased significantly in recent years to account for nearly 30% of epithelial ovarian cancer.

UNBS5162 inhibits SKOV3 ovarian cancer cell proliferation by regulating the PI3K/AKT signalling pathway

Ovarian cancer is the gynaecological malignancy with the highest mortality rate worldwide, and effective and safe therapeutic methods are limited. UNBS5162, a derivative of naphthalimide, has a clear inhibitory effect on the proliferation of various tumour cells in vitro and in vivo as a pan-antagonist of CXC chemokine ligand expression, but whether it serves a function in ovarian cancer remains unclear. The aim of the present study was to determine the effects of UNBS5162 on the proliferation, migration and invasion of ovarian cancer cells. The cell viability was detected using a Cell Counting Kit-8 (CCK-8) assay. The invasion and migration of SKOV3 cells were determined using Transwell assays. Cell apoptosis was determined using flow cytometry. The apoptosis-associated proteins and associated factors, such as phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signalling pathway members, were detected using western blot analysis. The CCK-8 assay revealed that SKOV3 cell viability was affected by UNBS5162 in a dose- and time-dependent manner. In Transwell assays, UNBS5162 inhibited cell invasion and migration. Furthermore, it was identified that UNBS5162 markedly increased the apoptosis rate of SKOV3 cells. Simultaneously, the expression of the anti-apoptotic protein B-cell lymphoma 2 (Bcl-2) was decreased and the expression of the pro-apoptotic proteins active caspase-3 and Bcl-2-associated X protein were increased in SKOV3 cells treated with UNBS5162. In addition, the expression levels of phospho (p-)AKT/total AKT, p-mammalian target of rapamycin (mTOR)/total mTOR, p-p70 S6 kinase (p70S6K)/total p70S6K and cyclin D1 were decreased in the UNBS5162-treated group. The results of the present study indicated that UNBS5162 inhibits proliferation, migration and invasion, and induces apoptosis in ovarian cancer cells, which may be regulated by the PI3K/AKT signalling pathway. These results suggest that UNBS5162 may be a potential novel drug for clinical ovarian cancer treatment.

Statin therapy and association with ovarian cancer risk in the New England Case Control (NEC) study

Statins are widely used to lower blood cholesterol and reduce risk for cardiovascular diseases, but attention has recently focused on a role in cancer prevention or therapy. Here we present data from a large case-control study addressing whether statin use can lower the risk for epithelial ovarian cancer (EOC). Between 1992 and 2008, data including medications used for at least 6 months were collected from 2,040 cases with EOC and 2,100 frequency-matched controls without the disease who participated in the New England Case Control study. We used unconditional logistic regression controlling for matching factors and potential confounders to examine the association between statin use and the risk for EOC. Overall, women who used statins had 32% lower risk of ovarian cancer compared to non-users (Odds ratio (OR) 0.68, 95% Confidence Interval (CI): 0.54-0.85), adjusting for the matching factors and other covariates. The reduced risk was most apparent in women taking a lipophilic statin who began use after age 49, and who had used them 2-4.9 years. Statin use was associated with lower risks for both serous and non-serous histologic subtypes with the strongest effect seen for mucinous and mixed epithelial subtypes. The association became apparent about a decade after the introduction of statins and did not appear to be confounded by indications for use of statins or medications used concomitantly. In this case-control study, statins were found to lower the risk for both serous and non-serous EOC and especially mucinous EOC.

rs495139 in the TYMS-ENOSF1 Region and Risk of Ovarian Carcinoma of Mucinous Histology

Thymidylate synthase (TYMS) is a crucial enzyme for DNA synthesis. TYMS expression is regulated by its antisense mRNA, ENOSF1. Disrupted regulation may promote uncontrolled DNA synthesis and tumor growth. We sought to replicate our previously reported association between rs495139 in the TYMS-ENOSF1 3' gene region and increased risk of mucinous ovarian carcinoma (MOC) in an independent sample. Genotypes from 24,351 controls to 15,000 women with invasive OC, including 665 MOC, were available. We estimated per-allele odds ratios (OR) and 95% confidence intervals (CI) using unconditional logistic regression, and meta-analysis when combining these data with our previous report. The association between rs495139 and MOC was not significant in the independent sample (OR = 1.09; 95% CI = 0.97⁻1.22; p = 0.15; N = 665 cases). Meta-analysis suggested a weak association (OR = 1.13; 95% CI = 1.03⁻1.24; p = 0.01; N = 1019 cases). No significant association with risk of other OC histologic types was observed (p = 0.05 for tumor heterogeneity). In expression quantitative trait locus (eQTL) analysis, the rs495139 allele was positively associated with ENOSF1 mRNA expression in normal tissues of the gastrointestinal system, particularly esophageal mucosa (r = 0.51, p = 1.7 × 10-28), and nonsignificantly in five MOC tumors. The association results, along with inconclusive tumor eQTL findings, suggest that a true effect of rs495139 might be small.

Epigenetics in ovarian cancer

Ovarian cancer is a disease with a poor prognosis and little progress has been made to improve treatment. It is now recognized that there are several histotypes of ovarian cancer, each with distinct epidemiologic and genomic characteristics. Cancer therapy is moving beyond classical chemotherapy to include epigenetic approaches. Epigenetics is the dynamic regulation of gene expression by DNA methylation and histone post translational modification in response to environmental cues. Improvement in technology to study DNA methylation has enabled a more agnostic approach and, with larger samples sets, has begun to unravel how epigenetics contributes to the etiology, response to chemotherapy and prognosis in of ovarian cancer. Investigations into histone modifications in ovarian cancer are more nascent. Much more is needed to be done to fully realize the potential that epigenetics holds for ovarian cancer clinical care.

Preterm delivery is associated with an increased risk of epithelial ovarian cancer among parous women

Epithelial ovarian cancer is a fatal disease of largely unknown etiology. Higher parity is associated with reduced risk of ovarian cancer. However, among parous women, the impact of pregnancy-related factors on risk is not well understood. This population-based case-control study included all parous women with epithelial ovarian cancer in Denmark, Finland, Norway and Sweden during 1967-2013 (n = 10,957) and up to 10 matched controls (n = 107,864). We used conditional logistic regression to estimate odds ratios (ORs) with 95% confidence intervals (CIs) for pregnancy-related factors and ovarian cancer risk by histological subtype. Preterm delivery was associated with an increased risk [pregnancy length (last pregnancy) ≤30 vs. 39-41 weeks, OR 1.33 (95% CI 1.06-1.67), adjusted for number of births]; the OR increased as pregnancy length decreased (p for trend < 0.001). Older age at first and last birth was associated with a decreased risk [first birth: 30-39 vs. <25 years: adjusted OR 0.76 (95% CI 0.70-0.83); last birth 30-39 vs. <25 years: adjusted OR 0.76 (95% CI 0.71-0.82)]. Increasing number of births was protective [≥4 births vs. 1; OR 0.63 (95% CI 0.59-0.68)] for all subtypes, most pronounced for clear-cell tumors [OR 0.30, (95% CI 0.21-0.44), p_{heterogeneity}  < 0.001]. No associations were observed for multiple pregnancies, preeclampsia or offspring size. In conclusion, in addition to high parity, full-term pregnancies and pregnancies at older ages were associated with decreased risk of ovarian cancer. Our findings favor the cell clearance hypothesis, i.e. a recent pregnancy provides protection by clearing of precancerous cells from the epithelium of the ovary/fallopian tubes, mediated by placental or ovarian hormones.

Prucalopride Inhibits Proliferation of Ovarian Cancer Cells via Phosphatidylinositol 3-Kinase (PI3K) Signaling Pathway

BACKGROUND Ovarian cancer is the second most common malignant tumor of the female reproductive system and is the leading cause of death of gynecological malignancies, but at present there is no effective and safe therapy. There is no previously published report on the anti-cancer effect of prucalopride, which is a high-affinity 5-HT4 receptor. The aim of the present study was to determine whether prucalopride can inhibit proliferation of ovarian cancer cells. MATERIAL AND METHODS The cell viability was detected by use of the Cell Counting Kit-8 (CCK-8) assay. The invasion and migration of SKOV3 and OVCAR3 cells was detected by Transwell assay. The cell apoptosis was detected by apoptosis flow detection and Caspase-Glo 3/7 Assay Systems. The apoptosis-related proteins, autophagy marker proteins, and the related-factors of phosphatidylinositol 3-kinase (PI3K) were detected by Western blot. RESULTS The CCK-8 proliferation test showed that prucalopride inhibited the growth of ovarian cancer cell lines SKOV3 and OVCAR3. In the Transwell assay, prucalopride inhibited cell invasion and migration. Furthermore, we found the expression of anti-apoptotic protein Bcl-2 decreased, whereas the expression of pro-apoptotic protein Caspase3 and Bax increased in the SKOV3 cell line treated with prucalopride, as well as cleaved PARP. In addition, the expression of p-AKT, p-mTOR, and p70S6K decreased in the prucalopride-treated group, and the expression of autophagy marker protein LC3-II/I and Beclin1 significantly increased, whereas the expression of p62 protein decreased. CONCLUSIONS The present study reveals that in ovarian cancer cells, prucalopride inhibits proliferation, migration, and invasion, and induces apoptosis and autophagy, which may be regulated by the PI3K signaling pathway. These results suggest prucalopride has potential as a new drug for clinical ovarian cancer treatment.

Preoperative assessment of ovarian tumors using a modified multivariate index assay

Background

Preoperative differentiation between benign and malignant masses can be challenging. The aim of this research was to evaluate the performance of a modified multivariate index assay (MIA) in detecting ovarian cancer and to compare the effectiveness of gynecologist assessment, cancer antigen (CA) 125, and MIA for identifying ovarian masses with high suspicion of malignancy.

Results

This prospective observational study included 150 women with ovarian masses who underwent surgery in the Maternity Teaching Hospital from December 2014 to May 2016. Preoperative estimation of modified MIA, assessment by a gynecologist, and CA 125 level correlated with the surgical histopathology. A modified MIA was implemented because of lack of access to the software typically used. Among 150 enrolled women there were 30 cases of malignancy, including 8 cases (26%) of early-stage ovarian cancer and 22 cases (74%) of late-stage cancer. MIA showed high specificity (96.7%) in detecting cancer and a sensitivity of 70%, with a positive predictive value of 84% and a negative predictive value of 92.8%. No significant differences were detected between the MIA results and the histopathology results (P = 0.267). For early-stage ovarian cancer, the sensitivity of MIA was 100% compared with 75% for CA 125 alone.

Conclusion

MIA seems to be effective for evaluation of ovarian tumors with higher specificity and positive predictive value than CA 125 while maintaining high negative predictive value and with only a slightly lower overall sensitivity. For evaluation of early-stage ovarian cancer, MIA showed a much higher sensitivity that markedly outperformed CA 125 alone. This modified MIA strategy may be particularly useful in low resource setting.

Epidemiology of Second Primary Tumors in Women With Ovarian Cancer

OBJECTIVE

The last large study of second primary tumors (SPTs) in women with ovarian cancer was published in 1996, prior to major changes in the differential diagnosis and treatment. The present study reports on the incidence of SPTs in a contemporary cohort of patients with a diagnosis of ovarian cancer.

METHODS

Ovarian cancer patients with a diagnosis of an ovarian malignancy between 1992 and 2012 were identified and characterized from 13 registries of the Surveillance, Epidemiology, and End Results database.

RESULTS

Of 41,073 women with a diagnosis of an ovarian malignancy between 1992 and 2012, 1831 (4.5%) developed a microscopically confirmed SPT. There was no significant difference in the risk of developing an SPT at all sites between women with an ovarian cancer and the general population. There was an elevated risk of site-specific SPTs of the small intestine, vagina, thyroid gland, and acute nonlymphocytic leukemia in ovarian cancer patients compared with the general Surveillance, Epidemiology, and End Results population. Conversely, the risk of lung and non-Hodgkin lymphoma was significantly decreased in women with ovarian cancer. An elevated risk of SPTs was observed in women with mucinous, endometrioid, and germ cell tumors. White women had an overall decreased risk of developing a second primary solid tumor, whereas American Indian and Asian/Pacific Islander women had an overall increased risk of an SPT at any site.

CONCLUSIONS

The incidence of SPTs in women with ovarian cancer was not significantly different as compared with the general population. However, divergent rates of SPTs in relation to histology, latency, age, and race were observed.

Disparities in ovarian cancer survival in the United States (2001-2009): Findings from the CONCORD-2 study

BACKGROUND

Ovarian cancer is the fifth leading cause of cancer death among women in the United States. This study reports ovarian cancer survival by state, race, and stage at diagnosis using data from the CONCORD-2 study, the largest and most geographically comprehensive, population-based survival study to date.

METHODS

Data from women diagnosed with ovarian cancer between 2001 and 2009 from 37 states, covering 80% of the US population, were used in all analyses. Survival was estimated up to 5 years and was age standardized and adjusted for background mortality (net survival) using state-specific and race-specific life tables.

RESULTS

Among the 172,849 ovarian cancers diagnosed between 2001 and 2009, more than one-half were diagnosed at distant stage. Five-year net survival was 39.6% between 2001 and 2003 and 41% between 2004 and 2009. Black women had consistently worse survival compared with white women (29.6% from 2001-2003 and 31.1% from 2004-2009), despite similar stage distributions. Stage-specific survival for all races combined between 2004 and 2009 was 86.4% for localized stage, 60.9% for regional stage, and 27.4% for distant stage.

CONCLUSIONS

The current data demonstrate a large and persistent disparity in ovarian cancer survival among black women compared with white women in most states. Clinical and public health efforts that ensure all women who are diagnosed with ovarian cancer receive appropriate, guidelines-based treatment may help to decrease these disparities. Future research that focuses on the development of new methods or modalities to detect ovarian cancer at early stages, when survival is relatively high, will likely improve overall US ovarian cancer survival. Cancer 2017;123:5138-59. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Challenges and Opportunities in Studying the Epidemiology of Ovarian Cancer Subtypes

PURPOSE OF REVIEW

Only recently has it become clear that epithelial ovarian cancer (EOC) is comprised of such distinct histotypes--with different cells of origin, morphology, molecular features, epidemiologic factors, clinical features, and survival patterns-that they can be thought of as different diseases sharing an anatomical location. Herein, we review opportunities and challenges in studying EOC heterogeneity.

RECENT FINDINGS

The 2014 World Health Organization diagnostic guidelines incorporate accumulated evidence that high- and low-grade serous tumors have different underlying pathogenesis, and that, on the basis of shared molecular features, most high grade tumors, including some previously classified as endometrioid, are now considered to be high-grade serous. At the same time, several studies have reported that high-grade serous EOC, which is the most common histotype, is itself made up of reproducible subtypes discernable by gene expression patterns.

SUMMARY

These major advances in understanding set the stage for a new era of research on EOC risk and clinical outcomes with the potential to reduce morbidity and mortality. We highlight the need for multidisciplinary studies with pathology review using the current guidelines, further molecular characterization of the histotypes and subtypes, inclusion of women of diverse racial/ethnic and socioeconomic backgrounds, and updated epidemiologic and clinical data relevant to current generations of women at risk of EOC.

Challenges and Opportunities in Studying the Epidemiology of Ovarian Cancer Subtypes

Purpose of review

Only recently has it become clear that epithelial ovarian cancer (EOC) is comprised of such distinct histotypes--with different cells of origin, morphology, molecular features, epidemiologic factors, clinical features, and survival patterns-that they can be thought of as different diseases sharing an anatomical location. Herein, we review opportunities and challenges in studying EOC heterogeneity.

Recent findings

The 2014 World Health Organization diagnostic guidelines incorporate accumulated evidence that high- and low-grade serous tumors have different underlying pathogenesis, and that, on the basis of shared molecular features, most high grade tumors, including some previously classified as endometrioid, are now considered to be high-grade serous. At the same time, several studies have reported that high-grade serous EOC, which is the most common histotype, is itself made up of reproducible subtypes discernable by gene expression patterns.

Summary

These major advances in understanding set the stage for a new era of research on EOC risk and clinical outcomes with the potential to reduce morbidity and mortality. We highlight the need for multidisciplinary studies with pathology review using the current guidelines, further molecular characterization of the histotypes and subtypes, inclusion of women of diverse racial/ethnic and socioeconomic backgrounds, and updated epidemiologic and clinical data relevant to current generations of women at risk of EOC.

Current Gaps in Ovarian Cancer Epidemiology: The Need for New Population-Based Research

With recent ovarian cancer screening studies showing no clinically significant mortality benefit, preventing this disease, identifying high-risk populations, and extending survival remain priorities. However, several challenges are impeding progress in ovarian cancer research. With most studies capturing exposure information from 10 or more years ago, evaluation of how changing patterns of exposures, such as new oral contraceptive formulations and increased intrauterine device use, might influence ovarian cancer risk and survival is difficult. Risk factors for ovarian cancer should be evaluated in the context of tumor histotypes, which have unique molecular features and cells of origin; this is a task that requires large collaborative studies to achieve meaningful sample sizes. Importantly, identification of novel modifiable risk factors, in addition to those currently known to reduce risk (eg, childbearing, tubal ligation, oral contraceptive use), is needed; this is not feasibly implemented at a population level. In this Commentary, we describe important gaps in knowledge and propose new approaches to advance epidemiologic research to improve ovarian cancer prevention and survival, including updated classification of tumors, collection of data on changing and novel exposures, longer follow-up on existing studies, evaluation of diverse populations, development of better risk prediction models, and collaborating prospectively with consortia to develop protocols for new studies that will allow seamless integration for future pooled analyses.