Tubal ligation and risk of ovarian cancer subtypes: a pooled analysis of 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.

High-Grade Serous Ovarian Cancer-A Risk Factor Puzzle and Screening Fugitive

High-grade serous ovarian cancer (HGSOC) is the most lethal tumor of the female genital tract. Despite extensive studies and the identification of some precursor lesions like serous tubal intraepithelial cancer (STIC) or the deviated mutational status of the patients (BRCA germinal mutation), the pathophysiology of HGSOC and the existence of particular risk factors is still a puzzle. Moreover, a lack of screening programs results in delayed diagnosis, which is accompanied by a secondary chemo-resistance of the tumor and usually results in a high recurrence rate after the primary therapy. Therefore, there is an urgent need to identify the substantial risk factors for both predisposed and low-risk populations of women, as well as to create an economically and clinically justified screening program. This paper reviews the classic and novel risk factors for HGSOC and methods of diagnosis and prediction, including serum biomarkers, the liquid biopsy of circulating tumor cells or circulating tumor DNA, epigenetic markers, exosomes, and genomic and proteomic biomarkers. The novel future complex approach to ovarian cancer diagnosis should be devised based on these findings, and the general outcome of such an approach is proposed and discussed in the paper.

Ovarian Cancer: From Precursor Lesion Identification to Population-Based Prevention Programs

Epithelial ovarian cancer (EOC) is a heterogeneous group of malignancies, including high-grade serous ovarian cancer (HGSC). HGSC is often diagnosed at advanced stages and is linked to TP53 variants. While BRCA variants elevate risk, most HGSC cases occur in individuals without known genetic variants, necessitating prevention strategies for people without known high-risk genetic variants. Effective prevention programs are also needed due to the lack of traditional screening options. An emerging primary prevention strategy is opportunistic salpingectomy, which involves removing fallopian tubes during another planned pelvic surgery. Opportunistic salpingectomy offers a safe and cost-effective preventative option that is gaining global adoption. With the publication of the first cohort study of patients who underwent salpingectomy, specifically for cancer prevention, attention has turned to broadening opportunities for salpingectomy in addition to more targeted approaches. Prevention opportunities are promising with increasing adoption of salpingectomy and the increased understanding of the etiology of the distinct histotypes of ovarian cancer. Yet, further research on targeted risk-reducing salpingectomy with thoughtful consideration of equity is necessary to reduce death and suffering from ovarian cancer.

Risk of ovarian cancer after salpingectomy and tubal ligation: Prospects on histology and time since the procedure

OBJECTIVE

Recent theories propose that most epithelial ovarian cancer (EOC), depending on histological type, originate from other gynecological tissues and involve the ovary secondarily. According to these theories, any protective effect of salpingectomy and tubal ligation may vary by histological type. The study aim was to examine the association between salpingectomy and tubal ligation, respectively, and risk of EOC, with a focus on associations specific for histological types.

METHODS

We identified EOC cases and matching controls in national registries and gathered information on surgical procedures and potential confounders. Conditional logistic regression was used to estimate odds ratio (OR) with 95% confidence interval (CI) of EOC related to salpingectomy and tubal ligation, respectively, overall and stratified by histological type. Furthermore, we investigated the association according to timing of the procedures.

RESULTS

Our study comprised 16,822 EOC cases. Each case was matched with 40 controls. There was an overall EOC risk reduction after unilateral (OR = 0.73; 95% CI: 0.60-0.87) and bilateral salpingectomy (OR = 0.46; 95% CI: 0.31-0.67). A slight risk reduction was seen among women with previous tubal ligation (OR = 0.91; 95% CI: 0.83-0.99). For salpingectomy, the risk reduction increased with increasing time since the surgical procedure and was only present among women younger than 50 years at salpingectomy. Unilateral and bilateral salpingectomy was associated with a risk reduction for most histological types.

CONCLUSION

The association between previous salpingectomy and reduced risk of several histological subtypes of EOC supports the suggested theories about the site of origin of EOC and may be of clinical importance.

Vaginal bacteria elicit acute inflammatory response in fallopian tube organoids: a model for pelvic inflammatory disease

Objective: To facilitate in vitro mechanistic studies in pelvic inflammatory disease (PID) and subsequent tubal factor infertility, as well as ovarian carcinogenesis, we sought to establish patient tissue derived fallopian tube (FT) organoids and to study their inflammatory response to acute vaginal bacterial infection. Design: Experimental study. Setting: Academic medical and researchcenter. Patients: FT tissues were obtained from four patients after salpingectomy for benign gynecological diseases. Interventions: We introduced acute infection in the FT organoid culture system by inoculating the organoid culture media with two common vaginal bacterial species, Lactobacillus crispatus and Fannyhesseavaginae . Main Outcome Measures: The inflammatory response elicited in the organoids after acute bacterial infection was analyzed by the expression profile of 249 inflammatory genes. Results: Compared to the negative controls that were not cultured with any bacteria, the organoids cultured with either bacterial species showed multiple differentially expressed inflammatory genes. Marked differences were noted between the Lactobacillus crispatus infected organoids and those infected by Fannyhessea vaginae . Genes from the C-X-C motif chemokine ligand (CXCL) family were highly upregulated in F. vaginae infected organoids. Flow cytometry showed that immune cells quickly disappeared during the organoid culture, indicating the inflammatory response observed with bacterial culture was generated by the epithelial cells in the organoids. Conclusion : Patient tissue derived FT organoids respond to acute bacterial infection with upregulation of inflammatory genes specific to different vaginal bacterial species. FT organoids is a useful model system to study the host-pathogen interaction during bacterial infection which may facilitate mechanistic investigations in PID and its contribution to tubal factor infertility and ovarian carcinogenesis.

Vaginal bacteria elicit acute inflammatory response in fallopian tube organoids: a model for pelvic inflammatory disease

Objective

To facilitate in vitro mechanistic studies in pelvic inflammatory disease (PID) and subsequent tubal factor infertility, as well as ovarian carcinogenesis, we sought to establish patient tissue derived fallopian tube (FT) organoids and to study their inflammatory response to acute vaginal bacterial infection.

Design

Experimental study.

Setting

Academic medical and research center.

Patients

FT tissues were obtained from four patients after salpingectomy for benign gynecological diseases.

Interventions

We introduced acute infection in the FT organoid culture system by inoculating the organoid culture media with two common vaginal bacterial species, Lactobacillus crispatus and Fannyhessea vaginae .

Main Outcome Measures

The inflammatory response elicited in the organoids after acute bacterial infection was analyzed by the expression profile of 249 inflammatory genes.

Results

Compared to the negative controls that were not cultured with any bacteria, the organoids cultured with either bacterial species showed multiple differentially expressed inflammatory genes. Marked differences were noted between the Lactobacillus crispatus infected organoids and those infected by Fannyhessea vaginae . Genes from the C-X-C motif chemokine ligand (CXCL) family were highly upregulated in F. vaginae infected organoids. Flow cytometry showed that immune cells quickly disappeared during the organoid culture, indicating the inflammatory response observed with bacterial culture was generated by the epithelial cells in the organoids.

Conclusion

Patient tissue derived FT organoids respond to acute bacterial infection with upregulation of inflammatory genes specific to different vaginal bacterial species. FT organoids is a useful model system to study the host-pathogen interaction during bacterial infection which may facilitate mechanistic investigations in PID and its contribution to tubal factor infertility and ovarian carcinogensis.

Modification of the Association Between Frequent Aspirin Use and Ovarian Cancer Risk: A Meta-Analysis Using Individual-Level Data From Two Ovarian Cancer Consortia

PURPOSE

Frequent aspirin use has been associated with reduced ovarian cancer risk, but no study has comprehensively assessed for effect modification. We leveraged harmonized, individual-level data from 17 studies to examine the association between frequent aspirin use and ovarian cancer risk, overall and across subgroups of women with other ovarian cancer risk factors.

METHODS

Nine cohort studies from the Ovarian Cancer Cohort Consortium (n = 2,600 cases) and eight case-control studies from the Ovarian Cancer Association Consortium (n = 5,726 cases) were included. We used Cox regression and logistic regression to assess study-specific associations between frequent aspirin use (≥ 6 days/week) and ovarian cancer risk and combined study-specific estimates using random-effects meta-analysis. We conducted analyses within subgroups defined by individual ovarian cancer risk factors (endometriosis, obesity, family history of breast/ovarian cancer, nulliparity, oral contraceptive use, and tubal ligation) and by number of risk factors (0, 1, and ≥ 2).

RESULTS

Overall, frequent aspirin use was associated with a 13% reduction in ovarian cancer risk (95% CI, 6 to 20), with no significant heterogeneity by study design (P = .48) or histotype (P = .60). Although no association was observed among women with endometriosis, consistent risk reductions were observed among all other subgroups defined by ovarian cancer risk factors (relative risks ranging from 0.79 to 0.93, all P-heterogeneity > .05), including women with ≥ 2 risk factors (relative risk, 0.81; 95% CI, 0.73 to 0.90).

CONCLUSION

This study, the largest to-date on aspirin use and ovarian cancer, provides evidence that frequent aspirin use is associated with lower ovarian cancer risk regardless of the presence of most other ovarian cancer risk factors. Risk reductions were also observed among women with multiple risk factors, providing proof of principle that chemoprevention programs with frequent aspirin use could target higher-risk subgroups.

The role of nutrition in harnessing the immune system: a potential approach to prevent cancer

Cancer is a vital barrier to increase the life expectancy and the foremost cause of death globally. The initial diagnosis and proper management of cancer can expand the survival rate of individuals. This review provides an in-depth investigation of cancer causes symptoms, types of cancer, and worldwide distribution of cancer. The relation between nutrition (i.e., various food items) and cancer is also emphasized to offer a framework of nutrition management in different cancer types. The microbiota is closely associated with the occurrence of cancer. Thus, genomics of intestinal microbes and nutrigenomics have been discussed based on the reported meta-analysis studies. A dramatic increase in cancer rates has been observed due to intake of alcohol, microbial infections, and deficiency of nutrition. Malnutrition is a substantial problem in cancer patients linked with improper treatment and increased morbidity. The detail studies of cancer and nutrigenomics are an eminent approach to comprehend the relation between microbes and the consumption of certain food types which can further reduce the cancer risk. The incorporation of specific nutrients and probiotics improved the gut microbial health, increased life expectancy, and also decreased the incidence of tumorigenesis in individuals.

Outcomes From Opportunistic Salpingectomy for Ovarian Cancer Prevention

IMPORTANCE

Opportunistic salpingectomy (OS), which is the removal of fallopian tubes during hysterectomy or instead of tubal ligation without removal of ovaries, is recommended to prevent ovarian cancer, particularly serous ovarian cancer. However, the effectiveness of OS is still undetermined.

OBJECTIVE

To examine observed vs expected rates of ovarian cancer among individuals who have undergone OS.

DESIGN, SETTING, AND PARTICIPANTS

This is a population-based, retrospective cohort study of all individuals in British Columbia, Canada, who underwent OS or a control surgery (hysterectomy alone or tubal ligation) between 2008 and 2017, with follow-up until December 31, 2017. Those with any gynecological cancer diagnosed before or within 6 months of their procedure were excluded. Data analysis was performed from April to August 2021.

EXPOSURES

Removal of both fallopian tubes at the time of hysterectomy or instead of tubal ligation while leaving ovaries intact.

MAIN OUTCOMES AND MEASURES

An ovarian cancer diagnosis listed in the British Columbia Cancer Registry. Age-specific rates of epithelial and serous ovarian cancer in the control group were combined with the specific follow-up time in the OS group to calculate expected numbers (and 95% CIs) of ovarian cancers in the OS group. These were compared with observed numbers. Age-adjusted expected and observed numbers of breast and colorectal cancers were also examined in the OS group.

RESULTS

There were 25 889 individuals who underwent OS (mean [SD] age, 40.2 [7.1] years; median [IQR] follow-up, 3.2 [1.6-5.1] years) and 32 080 who underwent hysterectomy alone or tubal ligation (mean [SD] age, 38.2 [7.9] years; median [IQR] follow-up, 7.3 [4.6-8.7] years). There were no serous ovarian cancers in the OS group and 5 or fewer epithelial ovarian cancers. The age-adjusted expected number was 5.27 (95% CI, 1.78-19.29) serous cancers and 8.68 (95% CI, 3.36-26.58) epithelial ovarian cancers. Age-adjusted expected vs observed numbers of breast cancers (22.1 expected vs 23 observed) and colorectal cancers (9.35 expected vs 8 observed) were not significantly different.

CONCLUSIONS AND RELEVANCE

In this cohort study, the OS group had significantly fewer serous and epithelial ovarian cancers than were expected according to the rate at which they arose in the control group. These findings suggest that OS is associated with reduced ovarian cancer risk.

Endometriosis and menopausal hormone therapy impact the hysterectomy-ovarian cancer association

OBJECTIVE

To evaluate the association between hysterectomy and ovarian cancer, and to understand how hormone therapy (HT) use and endometriosis affect this association.

METHODS

We conducted a pooled analysis of self-reported data from 11 case-control studies in the Ovarian Cancer Association Consortium (OCAC). Women with (n = 5350) and without ovarian cancer (n = 7544) who never used HT or exclusively used either estrogen-only therapy (ET) or estrogen+progestin therapy (EPT) were included. Risk of invasive epithelial ovarian cancer adjusted for duration of ET and EPT use and stratified on history of endometriosis was determined using odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Overall and among women without endometriosis, there was a positive association between ovarian cancer risk and hysterectomy (OR = 1.19, 95% CI 1.09-1.31 and OR = 1.20, 95% CI 1.09-1.32, respectively), but no association upon adjusting for duration of ET and EPT use (OR = 1.04, 95% CI 0.94-1.16 and OR = 1.06, 95% CI 0.95-1.18, respectively). Among women with a history of endometriosis, there was a slight inverse association between hysterectomy and ovarian cancer risk (OR = 0.93, 95% CI 0.69-1.26), but this association became stronger and statistically significant after adjusting for duration of ET and EPT use (OR = 0.69, 95% CI 0.48-0.99).

CONCLUSIONS

The hysterectomy-ovarian cancer association is complex and cannot be understood without considering duration of ET and EPT use and history of endometriosis. Failure to take these exposures into account in prior studies casts doubt on their conclusions. Overall, hysterectomy is not risk-reducing for ovarian cancer, however the inverse association among women with endometriosis warrants further investigation.

Does the "Devil" originate from the fallopian tubes?

Epithelial ovarian cancer (OC) is a heterogeneous disease and continues to be mostly diagnosed in advanced stages. The high lethality, the high rate of platinum-resistance, and the poor survival outcomes are the principal factors for categorizing OC among the most aggressive gynecological cancers. Only recently, a substantial progress has been made in our latest understanding of the origins of OC, particularly of high-grade serous histology. For a long time, the accumulation of genetic alterations in epithelial single layer cells of ovarian cysts caused by cyclic ovulations was considered as the most important driver and the long-standing dogma of ovarian tumorigenesis. Besides, the unique biological features and high histological heterogeneity of OC did not support this hypothesis. Indeed, various extra-ovarian cells of origin and multiple sites to each histotype were proposed, supported by cogent evidence from clinical cohorts and animal studies. In light of this enigma, this review was conducted to discuss the recent evidence supporting the revised origins of ovarian carcinoma histotypes with a particular focus on high-grade serous OC which may impact diagnostic and preventive approaches.

Risk of epithelial ovarian cancer Type I and II after hysterectomy, salpingectomy and tubal ligation-A nationwide case-control study

The proposed different origins and pathways to of the dualistic model of epithelial ovarian cancer (EOC) may affect and alter the potential risk reduction related to hysterectomy, salpingectomy and tubal ligation. The aim of our study was to analyze associations between hysterectomy, salpingectomy or tubal ligation and risk reduction of EOC Type I and II. In this nationwide register-based case-control study, women diagnosed with EOC, Fallopian tube or primary peritoneal cancer between 2008 and 2014 were included. Cases were classified into Type I and II according to histology and predefined criteria. The exposure variables: hysterectomy, salpingectomy and tubal ligation were identified from national registries. Conditional logistic regression analyses were performed to evaluate associations between Type I and II EOC and the exposure variables. Among 4669 registered cases, 4040 were eligible and assessed for subtyping resulting in 1033 Type I and 3007 Type II. Ten controls were randomly assigned to each case from the register of population. In regression analyses, women with previous salpingectomy had a significantly lower risk of EOC Type II (odds ratio [OR] 0.62; 95% confidence interval [95%CI] 0.45-0.85) but not Type I (OR 1.16; 95%CI 0.75-1.78). Hysterectomy was associated with a reduced risk of both EOC Type I (OR 0.71; 95%CI 0.52-0.99) and Type II (OR 0.81; 95%CI 0.68-0.96). Similar estimates were obtained for tubal ligation, although without statistical significance. The association between salpingectomy and reduced risk of EOC Type II supports the proposed theory of high-grade serous cancer originating from the tubal fimbriae.

Association of partner vasectomy, depot medroxyprogesterone acetate and intrauterine contraceptive devices with ovarian cancer

PURPOSE

To assess the associations between ovarian cancer and depot medroxyprogesterone acetate (DMPA), intrauterine contraceptive devices (IUDs), and partner vasectomy.

METHODS

We undertook a New Zealand-wide population-based case-control study. During 2013-2015, 205 eligible cases were identified from the cancer registry (152 [74%] participated) and 1,735 eligible controls were randomly selected from the electoral roll (837 [48%] participated). A postal questionnaire was used to gather information.

RESULTS

Ever-use of vasectomy was inversely associated with ovarian cancer in age-adjusted analysis, but not in multivariable analysis (OR = 0.67, 95% CI = 0.46-0.96, and OR = 0.82; 95% CI = 0.54-1.23, respectively). A suggestive trend towards lower risk with longer duration of reliance on partner vasectomy was observed (P-trend = 0.08). Ever-use and duration of use of DMPA were not associated with ovarian cancer. Although ever-use of IUDs was not associated with ovarian cancer, duration of use of IUDs was associated with higher risk (P-trend = 0.04). There were also statistically significant inverse associations between ovarian cancer and use of oral contraceptives, parity, and breastfeeding.

CONCLUSIONS

Prolonged use of IUDs may increase the risk of ovarian cancer. It is also possible that an inverse association exists between ovarian cancer and partner vasectomy.

Ovarian Cancer Risk Factor Associations by Primary Anatomic Site: The Ovarian Cancer Cohort Consortium

BACKGROUND

Epithelial ovarian, fallopian tube, and primary peritoneal cancers have shared developmental pathways. Few studies have prospectively examined heterogeneity in risk factor associations across these three anatomic sites.

METHODS

We identified 3,738 ovarian, 337 peritoneal, and 176 fallopian tube incident cancer cases in 891,731 women from 15 prospective cohorts in the Ovarian Cancer Cohort Consortium. Associations between 18 putative risk factors and risk of ovarian, peritoneal, and fallopian tube cancer, overall and for serous and high-grade serous tumors, were evaluated using competing risks Cox proportional hazards regression. Heterogeneity was assessed by likelihood ratio tests.

RESULTS

Most associations did not vary by tumor site (P het ≥ 0.05). Associations between first pregnancy (P het = 0.04), tubal ligation (P het = 0.01), and early-adult (age 18-21 years) body mass index (BMI; P het = 0.02) and risk differed between ovarian and peritoneal cancers. The association between early-adult BMI and risk further differed between peritoneal and fallopian tube cancer (P het = 0.03). First pregnancy and tubal ligation were inversely associated with ovarian, but not peritoneal, cancer. Higher early-adult BMI was associated with higher risk of peritoneal, but not ovarian or fallopian tube, cancer. Patterns were generally similar when restricted to serous and high-grade serous cases.

CONCLUSIONS

Ovarian, fallopian tube, and primary peritoneal cancers appear to have both shared and distinct etiologic pathways, although most risk factors appear to have similar associations by anatomic site.

IMPACT

Further studies on the mechanisms underlying the differences in risk profiles may provide insights regarding the developmental origins of tumors arising in the peritoneal cavity and inform prevention efforts.

Fallopian tube endometriosis in women undergoing operative video laparoscopy and its clinical implications

OBJECTIVE

To determine the incidence of fallopian tube endometriosis in patients undergoing laparoscopic surgery with a preoperative diagnosis of endometriosis, pelvic pain, infertility, or cystic adnexal mass.

DESIGN

Retrospective cross-sectional study.

SETTING

Gynecologic oncology and minimally invasive surgery practice.

PATIENT(S)

All patients who underwent surgery for endometriosis from July 2015 to June 2018 were included. Exclusion criteria were age ≥55 years, diagnosis of cancer, laparotomy, previous bilateral salpingectomy, and preoperative diagnosis other than endometriosis, pelvic pain, infertility, or cystic adnexal mass.

INTERVENTION(S)

Subjects were divided by those who did and those who did not have a salpingectomy at the time of surgery.

MAIN OUTCOME MEASURE(S)

Diagnosis of tubal endometriosis was based on macroscopic evidence of endometrial implants on the fallopian tube(s) noted within the operative report and microscopic evidence of endometriosis noted within the pathology report.

RESULT(S)

A total of 444 surgeries were performed and 185 met the study criteria. Among those, 153 (82.7%) had histologically diagnosed endometriosis within the abdominopelvic cavity. The incidence of tubal endometriosis was 11%-12% macroscopically and 42.5% microscopically after salpingectomy. Patients with tubal endometriosis were more likely to have severe disease.

CONCLUSION(S)

Among patients with endometriosis, the incidence of microscopic tubal endometriosis was significantly greater than that of macroscopic disease.

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.

Endometriosis-Associated Ovarian Cancer: The Origin and Targeted Therapy

Endometrial cysts (ECs) are thought to be the origin of endometriosis-associated ovarian cancer (EAOC). A hypothesis that the oxidative stress of iron in cysts causes “malignant transformation of ECs” has been proposed, but this has not been verified. Several population-based studies showed that endometriosis was a risk factor but did not reflect the “malignant transformation of ECs”. A review showed that most patients were diagnosed with EAOC early in monitoring following detection of ECs, and that these cases might have been cancer from the start. Epidemiologically, EAOC was reduced by hysterectomy rather than by cystectomy of ECs. Gene mutation analyses identified oncogenic mutations in endometriosis and normal endometrium and revealed that the same mutations were present at different endometriotic lesions. It was also shown that most of the gene mutations found in endometriosis occurred in normal endometrium. Taking together, EAOC might be caused by eutopic endometrial glandular epithelial cells with oncogenic mutations that have undergone menstrual blood reflux and engrafted in the ovary, rather than by low-risk ECs acquiring oncogenic mutations and becoming malignant. This review discusses the mechanisms of EAOC development and targeted therapy based on genetic variation in EAOC with a focus on eutopic endometrium.

Salpingectomie bilatérale aux fins de contraception permanente : série de cas et facteurs limitant le changement de pratique

OBJECTIVE

The Society of Obstetricians and Gynaecologists of Canada (SOGC) and the Society of Gynaecologic Oncology of Canada (GOC) recommend complete removal of the fallopian tubes as a permanent contraceptive method because of its association with a reduced risk of ovarian cancer. Currently, many women are not offered bilateral salpingectomy as an alternative to tubal ligation for permanent contraception.

METHOD

As part of a quality improvement initiative, we reviewed all cases of sterilization performed at our university centre between 1 January and 31 December 2018. A literature review of the clinical and ethical considerations that prevent clinicians from offering bilateral salpingectomy as permanent contraception is also presented.

RESULTS

The records of 111 women who underwent tubal sterilization were reviewed. Of these, 31.5% underwent bilateral salpingectomy; 46.8% underwent tubal fulguration; 12.6% underwent clip ligation; and 9.1% underwent tubal implant ligation (Essure). According to the information on file, only 36.3% of women were offered bilateral salpingectomy, and of these, 83.8% chose this method.

CONCLUSION

Bilateral salpingectomy should be offered to all women seeking permanent contraception. The benefits and very low risks associated with this procedure should make it a first choice option.

Associations of CXCL1 gene 5'UTR variations with ovarian cancer

BACKGROUND

There are about 2.4 hundred thousand new cases and 1.5 hundred thousand deaths of ovarian cancer (OC) annually in the world. Chronic inflammation is a risk factor for OC. C-X-C motif chemokine ligand 1 (CXCL1) defects may facilitate inflammation and transactivate EGFR in ovarian cancer, but the precise haplotypes associated with the potential diseases remained largely unknown. In this work, we characterized CXCL1 gene variations to elucidate their possible associations with OC.

METHODS

We analyzed the CXCL1 gene for 300 OC patients with 400 healthy participants as controls. The statistical analyses and Hardy-Weinberg equilibrium tests of the patients and control populations were conducted using the SPSS software (version 19.0) and Plink (version 1.9).

RESULTS

The variants rs11547681, rs201090116, rs199791199, rs181868085, rs4074 and rs1814092 within or near the CXCL1 gene were characterized. The genetic heterozygosity of rs11547681 and rs4074 was very high. Statistical analysis showed that the variant rs11547681 in the gene was closely associated with the risk of OC in the Chinese Han population, although this variant was not associated with FIGO stages or pathological grades of the patients.

CONCLUSIONS

Rs11547681 in CXCL1 gene was associated with the risk of OC in the Chinese Han population.

Prophylactic salpingectomy for prevention of ovarian cancer at the time of elective laparoscopic cholecystectomy

Background

Most serous ovarian cancers are now understood to originate in the fallopian tubes. Removing the tubes (salpingectomy) likely reduces the risk of developing high‐grade serous ovarian cancer. Numerous gynaecological societies now recommend prophylactic (or opportunistic) salpingectomy at the time of gynaecological surgery in appropriate women, and this is widely done. Salpingectomy at the time of non‐gynaecological surgery has not been explored and may present an opportunity for primary prevention of ovarian cancer.

Methods

This study investigated whether prophylactic salpingectomy with the intention of reducing the risk of developing ovarian cancer would be accepted and could be accomplished at the time of elective laparoscopic cholecystectomy. Women aged at least 45 years scheduled for elective laparoscopic cholecystectomy were recruited. They were counselled and offered prophylactic bilateral salpingectomy at the time of cholecystectomy. Outcome measures were rate of accomplishment of salpingectomy, time and procedural steps needed for salpingectomy, and complications.

Results

A total of 105 patients were included in the study. The rate of acceptance of salpingectomy was approximately 60 per cent. Salpingectomy was performed in 98 of 105 laparoscopic cholecystectomies (93·3 per cent) and not accomplished because of poor visibility or adhesions in seven (6·7 per cent). Median additional operating time was 13 (range 4–45) min. There were no complications attributable to salpingectomy. One patient presented with ovarian cancer 28 months after prophylactic salpingectomy; histological re‐evaluation of the tubes showed a previously undetected, focal serous tubal intraepithelial carcinoma.

Conclusion

Prophylactic salpingectomy can be done during elective laparoscopic cholecystectomy.

Screening and Prevention for High-Grade Serous Carcinoma of the Ovary Based on Carcinogenesis-Fallopian Tube- and Ovarian-Derived Tumors and Incessant Retrograde Bleeding

High-grade serous carcinoma (HGSC) is the most common and lethal subtype of ovarian carcinoma. Many HGSCs are now believed to originate in the fallopian tube epithelium; ovarian surface epithelium is another possible origin. Thus, current screening methods, i.e., ultrasonography and serum CA-125 measurements, have a limitation in their early detection. Recently, circulating biomarkers, such as tumor DNA, autoantibody, and microRNA, have been investigated to detect HGSCs. As cancer cells in the fallopian tube flow into the endometrial cavity, the detection of exfoliated cells, tumor DNA, and proteome from samples obtained from the endometrial cavity or the cervix may be useful. The risk of ovarian serous carcinoma is affected by the use of oral contraceptive and menopausal hormone therapy (MHT). MHT regimens causing endometrial bleeding increase serous carcinoma risk, hence, incessant retrograde bleeding from the endometrial cavity into the Douglas pouch appears to play an important role in high-grade serous carcinogenesis. In this review, we provide an overview of current and novel screening methods and prevention approaches for ovarian and fallopian tube HGSC.

The influence of birth cohort and calendar period on global trends in ovarian cancer incidence

Ovarian cancer is the eighth most common cancer in women worldwide and incidence rates vary markedly by world region. Our study provides a comprehensive overview of ovarian cancer incidence trends globally, examining the influence of birth cohort and period of diagnosis on changing risk. We presented current patterns and trends of ovarian cancer incidence until 2012 using data from successive volumes of Cancer Incidence in Five Contents. The incidence of ovarian cancer is highest in northern and eastern European countries and in northern America. Declining trends were observed in most countries with the exception of a few central and eastern Asian countries. Marked declines were seen in Europe and North America for women aged 50-74 where rates have declined up to 2.4% (95% CI: -3.9, -0.9) annually in Denmark (DNK) over the last decade. Additionally, declines in the incidence rate ratio (IRR) were observed for generations born after the 1930s, with an additional strong period effect seen around 2000 in United States and DNK. In contrast, IRRs increased among younger generations born after the 1950s in Japan and Belarus. Overall, the favorable trends in ovarian cancer incidence is likely due to the increase use of oral contraceptive pills, and changes in the prevalence of other reproductive risk and protective factors for ovarian cancer over the years studied. Changes in disease classifications and cancer registry practices may also partially contribute to the variation in ovarian cancer incidence rates. Thus, continuous cancer surveillance is essential to detect the shifting patterns of ovarian cancer.

The differential distribution of bacteria between cancerous and noncancerous ovarian tissues in situ

Background

With the improvement of bacterial detection, the theory of the sterile female upper reproductive tract has been frequently challenged in recent years. However, thus far, no researchers have used ovaries as study targets.

Methods

Six women who were diagnosed with ovarian cancer were included in the cancer group, and ten women who were diagnosed with a noncancerous ovarian condition (including three patients with uterine myoma and seven patients with uterine adenomyosis) were included in the control group. Immunohistochemistry staining using an antibacterial lipopolysaccharide (LPS) antibody was used to confirm the presence of bacteria in the ovarian tissues. In addition, 16S rRNA sequencing was used to compare the differences in the bacteria between ovarian cancer tissues and noncancerous ovarian tissues. BugBase and Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) were used to predict the functional composition of the bacteria.

Results

Bacterial LPS was present in ovarian cancer tissue and noncancerous ovarian tissue, which implied the presence of bacteria in ovarian tissue. When compared to the noncancerous ovarian bacteria at the phylum level, the cancerous ovarian bacteria were composed of increased Aquificae and Planctomycetes and decreased Crenarchaeota. When predicting metagenomes, gene functions associated with the potentially pathogenic and the oxidative stress-tolerant phenotype were enriched in the ovaries of the cancer group. Forty-six significantly different KEGG pathways existed in the ovarian bacteria of the cancer group compared to that of the control group.

Conclusions

Different bacteria compositions were present in cancerous and noncancerous ovarian tissues.

Trial registration

Chines Clinical Trail Registry, CHiCTR1800020018, Registered 11 September 2018, http://www.chictr.org.cn/

Reproductive and Hormonal Factors and Risk of Ovarian Cancer by Tumor Dominance: Results from the Ovarian Cancer Cohort Consortium (OC3)

BACKGROUND

Laterality of epithelial ovarian tumors may reflect the underlying carcinogenic pathways and origins of tumor cells.

METHODS

We pooled data from 9 prospective studies participating in the Ovarian Cancer Cohort Consortium. Information on measures of tumor size or tumor dominance was extracted from surgical pathology reports or obtained through cancer registries. We defined dominant tumors as those restricted to one ovary or where the dimension of one ovary was at least twice as large as the other, and nondominant tumors as those with similar dimensions across the two ovaries or peritoneal tumors. Competing risks Cox models were used to examine whether associations with reproductive and hormonal risk factors differed by ovarian tumor dominance.

RESULTS

Of 1,058 ovarian cancer cases with tumor dominance information, 401 were left-dominant, 363 were right-dominant, and 294 were nondominant. Parity was more strongly inversely associated with risk of dominant than nondominant ovarian cancer (P heterogeneity = 0.004). Ever use of oral contraceptives (OC) was associated with lower risk of dominant tumors, but was not associated with nondominant tumors (P heterogeneity = 0.01). Higher body mass index was associated with higher risk of left-dominant tumors, but not significantly associated with risk of right-dominant or nondominant tumors (P heterogeneity = 0.08).

CONCLUSIONS

These data suggest that reproductive and hormonal risk factors appear to have a stronger impact on dominant tumors, which may have an ovarian or endometriosis origin.

IMPACT

Examining the associations of ovarian cancer risk factors by tumor dominance may help elucidate the mechanisms through which these factors influence ovarian cancer risk.

Natural history of ovarian high-grade serous carcinoma from time effects of ovulation inhibition and progesterone clearance of p53-defective lesions

High-grade serous carcinoma is the most common and devastating type of ovarian cancer; its etiology, mechanism of malignant transformation, and origin remain controversial. Recent studies have identified secretory cells at the fimbria of the fallopian tube as the cell-of-origin of high-grade serous carcinoma, acquiring TP53 mutation, evolving to tubal precursor lesions, including "p53 signature" and serous tubal intraepithelial carcinoma, and metastasizing to the ovary as clinically evident ovarian cancer. The etiological mechanisms associated with known epidemiological risk factors, i.e., ovulation and retrograde menstruation, have also been suggested. Mutagens and transforming growth factors, such as reactive oxygen species and insulin-like growth factor axis proteins, as well as the apoptosis-rescuing protein hemoglobin are abundantly present in the ovulatory follicular fluid and peritoneum fluid, which bathes the fimbrial epithelium, and induces malignant transformation after repeated exposure. In accordance with the proposed cleansing effect of progesterone from studies on oral contraceptive use or term pregnancy, a recent study indicated that the p53-null tubal epithelial cells are selectively cleared by progesterone depending on its progesterone receptor. In this report, by analyzing different time effects of oral contraceptive use or pregnancy in the prevention of ovarian cancer and by aligning them with the carcinogenic and cleansing clearance concepts of ovulation and progesterone, as well as the fact of progressive loss of progesterone receptor during tubal transformation, we deduced the natural history of ovarian high-grade serous carcinoma. The natural history begins at the first ovulation and spans for more than 30 years, taking 10 years from the normal tubal epithelium to the "p53 signature" status, another 15 years to progesterone receptor negative serous tubal intraepithelial carcinoma, and a final 5+ years to high-grade serous carcinoma. The estimated natural history may help understand the pathogenesis of high-grade serous carcinoma and defines the window for early detection and chemoprevention.

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.

Infection as a potential cofactor in the genetic-epigenetic pathophysiology of endometriosis: a systematic review

BACKGROUND

The genetic-epigenetic theory postulates that endometriosis is triggered by a cumulative set of genetic-epigenetic (GE) incidents. Pelvic and upper genital tract infection might induce GE incidents and thus play a role in the pathogenesis of endometriosis. Thus, this article aims to review the association of endometriosis with upper genital tract and pelvic infections.

METHODS

Pubmed, Scopus and Google Scholar were searched for 'endometriosis AND (infection OR PID OR bacteria OR viruses OR microbiome OR microbiota)', for 'reproductive microbiome' and for 'reproductive microbiome AND endometriosis', respectively. All 384 articles, the first 120 'best match' articles in PubMed for 'reproductive microbiome' and the first 160 hits in Google Scholar for 'reproductive microbiome AND endomytriosis' were hand searched for data describing an association between endometriosis and bacterial, viral or other infections. All 31 articles found were included in this manuscript.

RESULTS

Women with endometriosis have a significantly increased risk of lower genital tract infection, chronic endometritis, severe PID and surgical site infections after hysterectomy. They have more colony forming units of Gardnerella, Streptococcus, Enterococci and Escherichia coli in the endometrium. In the cervix Atopobium is absent, but Gardnerella, Streptococcus, Escherichia, Shigella, and Ureoplasma are increased. They have higher concentrations of Escherichia Coli and higher concentrations of bacterial endotoxins in menstrual blood. A Shigella/Escherichia dominant stool microbiome is more frequent. The peritoneal fluid of women with endometriosis contains higher concentrations of bacterial endotoxins and an increased incidence of mollicutes and of HPV viruses. Endometriosis lesions have a specific bacterial colonisation with more frequently mollicutes (54%) and both high and medium-risk HPV infections (11%). They contain DNA with 96% homology with Shigella. In mice transplanted endometrium changes the gut microbiome while the gut microbiome influences the growth of these endometriosis lesions.

CONCLUSIONS

Endometriosis is associated with more upper genital tract and peritoneal infections. These infections might be co-factors causing GE incidents and influencing endometriosis growth.

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.

No. 344-Opportunistic Salpingectomy and Other Methods of Risk Reduction for Ovarian/Fallopian Tube/Peritoneal Cancer in the General Population

OBJECTIVE

This guideline reviews the potential benefits of opportunistic salpingectomy to prevent the development of high grade serous cancers (HGSC) of the ovary/fallopian tube/peritoneum based on current evidence supporting the fallopian tube origin of disease.

INTENDED USERS

Gynaecologists, obstetricians, family doctors, registered nurses, nurse practitioners, residents, and health care providers.

TARGET POPULATION

Adult women (18 and older): OPTIONS: Women considering hysterectomy who wish to retain their ovaries in situ have traditionally also retained their fallopian tubes. In addition, women undergoing permanent surgical sterilization have usually undergone tubal ligation using various methods rather than undergoing surgical removal of the entire fallopian tube.

EVIDENCE

For the sections "Evidence Supporting the Hypothesis That HGSC Originates in the Fallopian Tube" and "Current Literature on the Effects and Safety of Opportunistic Salpingectomy," relevant studies were searched in PubMed, Medline, and the Cochrane Systematic Reviews using the following terms, either alone or in combination, with the search limited to English language materials: "high grade serous cancers ovary," "fallopian tube," "peritoneum," "opportunistic salpingectomy," "epithelial ovarian cancers," "origin," "tubal carcinoma in situ," "BRCA mutation," "prophylactic salpingectomy," "inflammation," "clear cell," and "endometrioid." The initial search was performed in March 2015 with a final literature search in March 2016. Relevant evidence was selected for inclusion in the following order: meta-analyses, systematic reviews, guidelines, randomized controlled trials, prospective cohort studies, observational studies, non-systematic reviews, case series, and reports. The total number of studies identified was 458, and 56 studies were included in this review. For the section "Other Factors Influencing the Risk of Developing "Ovarian" Cancers" a general Medline search was carried out using the terms "ovarian neoplasm" and "prevention." The search included papers published from December 2005 to March 2016. Meta-analyses were preferentially selected except where no such review was found. Additional searches for each subheading were also conducted (e.g., "ovarian neoplasm" and "tubal ligation.") Additional significant articles were identified through cross-referencing the identified reviews. For the search for "ovarian neoplasm" and "prevention," 10 meta-analyses were identified. For the search for "ovarian neoplasm" and "tubal ligation," an additional 4 meta-analyses were identified.

VALIDATION METHODS

The content and recommendations were drafted and agreed on by the principal authors. The Executive and Board of the Society of Gynecologic Oncology of Canada reviewed the content and submitted comments for consideration, and the Board of the SOGC approved the final draft for publication. The quality of evidence was rated using the criteria described in the Grading of Recommendations Assessment, Development and Evaluation methodology framework (Table 1). The interpretation of strong and weak recommendations is described in Table 2. The summary of findings is available on request.

BENEFITS, HARMS, AND/OR COSTS

The addition of opportunistic salpingectomy to a planned hysterectomy or permanent sterilization did not increase rates of hospital readmission (OR 0.91, 95% CI 0.75 to 1.10 and OR 0.8, 95% CI 0.56 to 1.21, respectively) or blood transfusions (OR 0.86, 95% CI 0.67 to 1.10 and OR 0.75, 95% CI 0.32 to 1.73, respectively) but did increase the overall operating time (by 16 minutes and 10 minutes, respectively) in a retrospective review of 43 931 women. The risk of repeat surgery for tubal pathology among women with retained fallopian tubes after hysterectomy was at least doubled (OR 2.13, 95% CI 1.88 to 2.42 in a population-based study of 170 000 women). If general gynaecologists were to consider removal of fallopian tubes at the time of every hysterectomy and sterilization procedure with referral of all patients with HGSC for hereditary cancer counselling and genetic testing, experts project a potential reduction in the rate of HGSC by 40% over the next 20 years.

GUIDELINE UPDATE

Evidence will be reviewed 5 years after publication to decide whether all or part of the guideline should be updated. However, if important new evidence is published prior to the 5-year cycle, the review process may be accelerated for a more rapid update of some recommendations.

SPONSORS

This guideline was developed with resources funded by the Society of Gynecologic Oncology of Canada and SOGC.

SUMMARY STATEMENTS

RECOMMENDATIONS.

A comprehensive gene-environment interaction analysis in Ovarian Cancer using genome-wide significant common variants

As a follow-up to genome-wide association analysis of common variants associated with ovarian carcinoma (cancer), our study considers seven well-known ovarian cancer risk factors and their interactions with 28 genome-wide significant common genetic variants. The interaction analyses were based on data from 9971 ovarian cancer cases and 15,566 controls from 17 case-control studies. Likelihood ratio and Wald tests for multiplicative interaction and for relative excess risk due to additive interaction were used. The top multiplicative interaction was noted between oral contraceptive pill (OCP) use (ever vs. never) and rs13255292 (p value = 3.48 × 10-4 ). Among women with the TT genotype for this variant, the odds ratio for OCP use was 0.53 (95% CI = 0.46-0.60) compared to 0.71 (95%CI = 0.66-0.77) for women with the CC genotype. When stratified by duration of OCP use, women with 1-5 years of OCP use exhibited differential protective benefit across genotypes. However, no interaction on either the multiplicative or additive scale was found to be statistically significant after multiple testing correction. The results suggest that OCP use may offer increased benefit for women who are carriers of the T allele in rs13255292. On the other hand, for women carrying the C allele in this variant, longer (5+ years) use of OCP may reduce the impact of carrying the risk allele of this SNP. Replication of this finding is needed. The study presents a comprehensive analytic framework for conducting gene-environment analysis in ovarian cancer.

Ovarian cancer in the world: epidemiology and risk factors

Aim: Ovarian cancer is one of the most common gynecologic cancers that has the highest mortality rate. Considering the fact that knowledge on the incidence, mortality of ovarian cancer, as well as its risk factors is necessary for planning and preventing complications, this study was conducted with the aim of examining the epidemiology and risk factors of ovarian cancer in the world.

Materials and methods: In order to access the articles, Medline, Web of Science Core Collection, and Scopus databases were searched from their start to the year 2018. Full-text, English observational studies that referred to various aspects of ovarian cancer were included in the study.

Results: In total, 125 articles that had been published during the years 1925–2018 were entered into the study. Ovarian cancer is the seventh most common cancer among women. Increased risk factors of cancer have led to an upward trend in the incidence of cancer around the world. In 2018, 4.4% of entire cancer-related mortality among women was attributed to ovarian cancer. Although the incidence of cancer is higher among high Human Development Index (HDI) countries, the trend of mortality rate tends to be reversing. Various factors affect the occurrence of ovarian cancer, from which genetic factor are among the most important ones. Pregnancy, lactation, and oral contraceptive pills play a role in reducing the risk of this disease.

Conclusion: This study provides significant evidence about ovarian cancer. Considering the heavy burden of ovarian cancer on women's health, preventive measures as well as health education and early detection in high risk groups of women are highly recommended. Although some risk factors cannot be changed, a focus on preventable risk factors may reduce the risk of ovarian cancer. More studies are needed to explore the role of unclear risk factors in ovarian cancer occurrence.

High-Grade Serous Ovarian Cancer: Basic Sciences, Clinical and Therapeutic Standpoints

Among a litany of malignancies affecting the female reproductive tract, that of the ovary is the most frequently fatal. Moreover, while the steady pace of scientific discovery has fuelled recent ameliorations in the outcomes of many other cancers, the rates of mortality for ovarian cancer have been stagnant since around 1980. Yet despite the grim outlook, progress is being made towards better understanding the fundamental biology of this disease and how its biology in turn influences clinical behaviour. It has long been evident that ovarian cancer is not a unitary disease but rather a multiplicity of distinct malignancies that share a common anatomical site upon presentation. Of these, the high-grade serous subtype predominates in the clinical setting and is responsible for a disproportionate share of the fatalities from all forms of ovarian cancer. This review aims to provide a detailed overview of the clinical-pathological features of ovarian cancer with a particular focus on the high-grade serous subtype. Along with a description of the relevant clinical aspects of this disease, including novel trends in treatment strategies, this text will inform the reader of recent updates to the scientific literature regarding the origin, aetiology and molecular-genetic basis of high-grade serous ovarian cancer (HGSOC).

High-Grade Serous Ovarian Cancer: Basic Sciences, Clinical and Therapeutic Standpoints

Among a litany of malignancies affecting the female reproductive tract, that of the ovary is the most frequently fatal. Moreover, while the steady pace of scientific discovery has fuelled recent ameliorations in the outcomes of many other cancers, the rates of mortality for ovarian cancer have been stagnant since around 1980. Yet despite the grim outlook, progress is being made towards better understanding the fundamental biology of this disease and how its biology in turn influences clinical behaviour. It has long been evident that ovarian cancer is not a unitary disease but rather a multiplicity of distinct malignancies that share a common anatomical site upon presentation. Of these, the high-grade serous subtype predominates in the clinical setting and is responsible for a disproportionate share of the fatalities from all forms of ovarian cancer. This review aims to provide a detailed overview of the clinical-pathological features of ovarian cancer with a particular focus on the high-grade serous subtype. Along with a description of the relevant clinical aspects of this disease, including novel trends in treatment strategies, this text will inform the reader of recent updates to the scientific literature regarding the origin, aetiology and molecular-genetic basis of high-grade serous ovarian cancer (HGSOC).

High-Grade Serous Ovarian Cancer: Basic Sciences, Clinical and Therapeutic Standpoints

Among a litany of malignancies affecting the female reproductive tract, that of the ovary is the most frequently fatal. Moreover, while the steady pace of scientific discovery has fuelled recent ameliorations in the outcomes of many other cancers, the rates of mortality for ovarian cancer have been stagnant since around 1980. Yet despite the grim outlook, progress is being made towards better understanding the fundamental biology of this disease and how its biology in turn influences clinical behaviour. It has long been evident that ovarian cancer is not a unitary disease but rather a multiplicity of distinct malignancies that share a common anatomical site upon presentation. Of these, the high-grade serous subtype predominates in the clinical setting and is responsible for a disproportionate share of the fatalities from all forms of ovarian cancer. This review aims to provide a detailed overview of the clinical-pathological features of ovarian cancer with a particular focus on the high-grade serous subtype. Along with a description of the relevant clinical aspects of this disease, including novel trends in treatment strategies, this text will inform the reader of recent updates to the scientific literature regarding the origin, aetiology and molecular-genetic basis of high-grade serous ovarian cancer (HGSOC).

Women's preferences for permanent contraception method and willingness to be randomized for a hypothetical trial

OBJECTIVE

To understand women's preferences for permanent contraception by salpingectomy or tubal occlusion following standardized counseling and evaluate the practicality of a future randomized trial.

STUDY DESIGN

We invited pregnant and non-pregnant women planning permanent contraception at the University of California, Davis (UCD) and University of Tennessee (UT) Obstetrics and Gynecology clinics to participate. We enrolled women when they received routine counseling and signed procedure consent. Participants received standardized information sheets reviewing permanent contraception options based on pregnancy status then completed an anonymous survey with questions about demographics, method preference, and willingness to participate in a hypothetical randomized trial comparing salpingectomy and tubal occlusion. We evaluated predictors for salpingectomy preference using multivariable analysis.

RESULTS

From July 2015 to October 2016, we enrolled 75 women at UCD and 63 women at UT. Overall, respondents preferred salpingectomy (63.0%); among the 47 women not currently pregnant at both sites, 40 (85.1%) preferred salpingectomy, most commonly because of higher efficacy. Although population characteristics differed significantly between the sites, only UCD site (aOR 4.2; 95% CI 1.9, 9.4) and non-pregnancy status (aOR 4.2; 95% CI 1.6, 10.8) predicted preference for salpingectomy in the multivariable model. Most participants (n=84, 60.9%) would not be willing to be randomized to a theoretical trial comparing salpingectomy and tubal occlusion procedures.

CONCLUSION

Among a diverse group of women from two different areas in the U.S. given a choice of permanent contraception methods, salpingectomy is preferred over tubal occlusion. Most women planning a permanent contraceptive procedure would not agree to a randomized comparison of these methods.

IMPLICATIONS STATEMENT

Salpingectomy, which offers theoretically higher efficacy and potentially greater ovarian cancer protection compared to tubal occlusion, is preferred by the majority of patients and should be offered to all women seeking permanent contraception. Differences in method choices less likely reflect the patient population and more likely the counseling provided.

Bilateral salpingectomy to reduce the risk of ovarian/fallopian/peritoneal cancer in women at average risk: a position statement of the Korean Society of Obstetrics and Gynecology (KSOG)

Based on the current understanding of a preventive effect of bilateral salpingectomy on ovarian/fallopian/peritoneal cancers, the Korean Society of Obstetrics and Gynecology, Korean Society of Gynecologic Endocrinology, Korean Society of Gynecologic Oncology, Korean Society of Maternal Fetal Medicine, and Korean Society for Reproductive Medicine support the following recommendations: • Women scheduled for hysterectomy for benign gynecologic disease should be informed that bilateral salpingectomy reduces the risk of ovarian/fallopian/peritoneal cancer, and they should be counseled regarding this procedure at the time of hysterectomy. • Although salpingectomy is generally considered as a safe procedure in terms of preserving ovarian reserve, there is a lack of evidences representing its long-term outcomes. Therefore, patients should be informed about the minimal potential of this procedure for decreasing ovarian reserve. • Prophylactic salpingectomy during vaginal hysterectomy is favorable in terms of prevention of ovarian/fallopian/peritoneal cancer, although operation-related complications minimally increase with this procedure, compared to the complications associated with vaginal hysterectomy alone. Conversion to open or laparoscopic approach from vaginal approach to perform prophylactic salpingectomy is not recommended. • Women who desire permanent sterilization at the time of cesarean delivery could be counseled for prophylactic salpingectomy before surgery on an individual basis.

Case for a role of the microbiome in gynecologic cancers: Clinician's perspective

In this review, we aimed to provide insight into the microbiome and its association with endometrial and ovarian cancer and their risk factors. We reviewed the literature focusing on the relationship between the microbiome and cancer, as well as the relationship between gynecologic diseases and cancers. The human body contains different kinds of microorganisms in various body parts, which is termed the microbiome. The number of microorganisms that live in and on the human body is greater than that of the human germ and somatic cells by 10-fold. The relationship between a human and their microbiome is complex; it is also one of the most important components of homeostasis. Impairment of microbiome-host homeostasis has been associated with obesity, several cancers, preterm labor, inflammatory and allergic conditions and neurodevelopmental disorders. Direct and strong causal relationships have been established for several cancers and microorganisms, such as gastric lymphoma and Helicobacter pylori infection. Interestingly, eradication of the infectious agents has also been shown to be therapeutic. The association between cancer and the microbiome, however, is more complicated than a 1 bacteria-1 cancer model, and a shift in a healthy microbiome can result in various cancers via inflammation, change in microenvironment or DNA-damaging toxins. The human microbiome is an integral part of homeostasis. Understanding the mechanisms that cause dysbiosis will enable us to elucidate the pathways that result in malignancy and investigate new treatment modalities.

Risk-reducing Surgery in Women at Low Lifetime Risk of Developing Ovarian Carcinoma: Opportunistic Salpingectomy

Lack of success in ovarian cancer control through screening or advances in treatment in the general population has prompted exploration in new avenues of prevention. "Opportunistic" salpingectomy describes a surgical procedure or risk-reducing intent in women at low-risk/general population risk for developing ovarian cancer who are undergoing pelvic/abdominal surgery for other indications. This chapter reviews the uptake, safety, and anticipated impact of this prevention initiative.

Preclinical Models of Ovarian Cancer: Pathogenesis, Problems, and Implications for Prevention

Preclinical models are relatively underutilized and underfunded resources for modeling the pathogenesis and prevention of ovarian cancers. Several reviews have detailed the numerous published models of ovarian cancer. In this review, we will provide an overview of experimental model systems, their strengths and limitations, and use selected models to illustrate how they can be used to address specific issues about ovarian cancer pathogenesis. We will then highlight some of the preclinical prevention studies performed to date and discuss experiments needed to address important unanswered questions about ovarian cancer prevention strategies.

Taking the Tube: From Normal Fallopian Tube Epithelium to Ovarian High-grade Serous Carcinoma

Detailed pathologic studies over the past decade suggest a distal fallopian tube origin for the majority of "ovarian" high-grade serous carcinomas (HGSC). This review will summarize molecular alterations observed in tubal precursors for HGSC, namely p53 signatures and serous tubal intraepithelial carcinomas, and in nonmalignant fallopian tube epithelial cells obtained from women at increased genetic risk for HGSC. Recent experiments investigating the impact of follicular fluid exposure and retrograde menstruation on tumor development in the fallopian tube will also be discussed. These data will be reconciled with traditional ovarian cancer risk factors related to reproductive history.

The role of pregnancy, perinatal factors and hormones in maternal cancer risk: a review of the evidence

An understanding of the origin of cancer is critical for cancer prevention and treatment. Complex biological mechanisms promote carcinogenesis, and there is increasing evidence that pregnancy-related exposures influence foetal growth cell division and organ functioning and may have a long-lasting impact on health and disease susceptibility in the mothers and offspring. Nulliparity is an established risk factor for breast, ovarian, endometrial and possibly pancreatic cancer, whilst the risk of kidney cancer is elevated in parous compared with nulliparous women. For breast, endometrial and ovarian cancer, each pregnancy provides an additional risk reduction. The associations of parity with thyroid and colorectal cancers are uncertain. The timing of reproductive events is also recognized to be important. Older age at first birth is associated with an increased risk of breast cancer, and older age at last birth is associated with a reduced risk of endometrial cancer. The risks of breast and endometrial cancers increase with younger age at menarche and older age at menopause. The mechanisms, and hormone profiles, that underlie alterations in maternal cancer risk are not fully understood and may differ by malignancy. Linking health registries and pooling of data in the Nordic countries have provided opportunities to conduct epidemiologic research of pregnancy exposures and subsequent cancer. We review the maternal risk of several malignancies, including those with a well-known hormonal aetiology and those with less established relationships. The tendency for women to have fewer pregnancies and at later ages, together with the age-dependent increase in the incidence of most malignancies, is expected to affect the incidence of pregnancy-associated cancer.

[Definition, description, clinicopathological features, pathogenesis and natural history of endometriosis: CNGOF-HAS Endometriosis Guidelines]

Endometriosis and adenomyosis are histologically defined. The frequency of endometriosis cannot be precisely estimated in the general population. Endometriosis is considered a disease when it causes pain and/or infertility. Endometriosis is a heterogeneous disease with three well-recognized subtypes that are often associated with each other: superficial endometriosis (SUP), ovarian endometrioma (OMA), and deep infiltrating endometriosis (DIE). DIE is frequently multifocal and mainly affects the following structures: the uterosacral ligaments, the posterior vaginal cul-de-sac, the bladder, the ureters, and the digestive tract (rectum, recto-sigmoid junction, appendix). The role of menstrual reflux in the pathophysiology of endometriosis is major and explains the asymmetric distribution of lesions, which predominate in the posterior compartment of the pelvis and on the left (NP3). All factors favoring menstrual reflux increase the risk of endometriosis (early menarche, short cycles, AUB, etc.). Inflammation and biosteroid hormones synthesis are the main mechanisms favoring the implantation and the growth of the lesions. Pain associated with endometriosis can be explained by nociception, hyperalgia, and central sensitization, associated to varying degrees in a single patient. Typology of pain (dysmenorrhea, deep dyspareunia, digestive or urinary symptoms) is correlated with the location of the lesions. Infertility associated with endometriosis can be explained by several non-exclusive mechanisms: a pelvic factor (inflammation), disrupting natural fertilization; an ovarian factor, related to oocyte quality and/or quantity; a uterine factor disrupting implantation. The pelvic factor can be fixed by surgical excision of the lesions that improves the chance of natural conception (NP2). The uterine factor can be corrected by an ovulation-blocking treatment that improves the chances of getting pregnant by in vitro fertilization (NP2). The impact of endometrioma exeresis on the ovarian reserve (NP2) should be considered when a surgery is scheduled. Endometriosis is a multifactorial disease, resulting from combined action of genetic and environmental factors. The risk of developing endometriosis for a first-degree relative is five times higher than in the general population (NP2). Identification of genetic variants involved in the disease has no implication for clinical practice for the moment. The role of environmental factors, particularly endocrine disrupters, is plausible but not demonstrated. Literature review does not support the progression of endometriosis over time, either in terms of the volume or the number of the lesions (NP3). The risk of acute digestive occlusion or functional loss of a kidney in patients followed for endometriosis seems exceptional. These complications were revealing the disease in the majority of cases. IVF does not increase the intensity of pain associated with endometriosis (NP2). There is few data on the influence of pregnancy on the lesions, except the possibility of a decidualization of the lesions that may give them a suspicious aspect on imaging. The impact of endometriosis on pregnancy is debated. There is an epidemiological association between endometriosis and rare subtypes of ovarian cancer (endometrioid and clear cell carcinomas) (NP2). However, the relative risk is moderate (around 1.3) (NP2) and the causal relationship between endometriosis and ovarian cancer is not demonstrated so far. Considering the low incidence of endometriosis-associated ovarian cancer, there is no argument to propose a screening or a risk reducing strategy for the patients.

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.