Pelvic inflammatory disease and risk of invasive ovarian cancer and ovarian borderline tumors

Exploring the Relationship between Ovarian Cancer and Genital Microbiota: A Systematic Review and Meta-Analysis

Ovarian cancer (OC) remains a significant health challenge globally, with high mortality rates despite advancements in treatment. Emerging research suggests a potential link between OC development and genital dysbiosis, implicating alterations in the microbiome composition as a contributing factor. To investigate this correlation, a meta-analysis was conducted following PRISMA and MOOSE guidelines, involving eight studies encompassing 3504 patients. Studies investigating the role of upper and inferior genital tract dysbiosis were included, with particular reference to HPV infection and/or history of pelvic inflammatory disease. The analysis revealed no significant difference in genital dysbiosis prevalence between OC patients and healthy controls. Although previous literature suggests associations between dysbiosis and gynecologic cancers, such as cervical and endometrial cancers, the findings regarding OC are inconclusive. Methodological variations and environmental factors may contribute to these discrepancies, underscoring the need for standardized methodologies and larger-scale studies. Despite the limitations, understanding the microbiome's role in OC development holds promise for informing preventive and therapeutic strategies. A holistic approach to patient care, incorporating microbiome monitoring and personalized interventions, may offer insights into mitigating OC risk and improving treatment outcomes. Further research with robust methodologies is warranted to elucidate the complex interplay between dysbiosis and OC, potentially paving the way for novel preventive and therapeutic approaches.

Asbestos Exposure and Ovarian Cancer: A Meta-analysis

Background

The International Agency for Research on Cancer (IARC) Monograph conducted a systematic review of the relationship between asbestos and ovarian cancer. However, there may have been information bias due to the undue weight given to few articles. To address this limitation, the present study performed a meta-analysis integrating studies published both before and after the 2012 IARC Monograph on Asbestos, with the aim of investigating the association between asbestos exposure and ovarian cancer.

Methods

A comprehensive search of major journal databases was conducted to identify studies examining the relationship between asbestos exposure and ovarian cancer, including those featured in the 2012 IARC Monograph on Asbestos. A meta-analysis on asbestos exposure and cancer risk was performed.

Results

The meta-analysis of studies published after the 2012 IARC Monograph on Asbestos found a summary Standardized Mortality Ratio (SMR) of 2.04 (95% CI: 1.03-4.05; p = 0.0123; 5 studies), with a significant degree of heterogeneity among the studies (I2 = 72.99%). The combined analysis of 15 studies before and after the 2012 IARC Monograph showed an overall summary SMR of 1.72 (95% CI: 1.43-2.06; p = 0.0349; 15 studies), with a moderate degree of heterogeneity (I2 = 42.99%).

Conclusion

This meta-analysis provides evidence of a significant association between asbestos exposure and ovarian cancer mortality. While the possibility of misdiagnosis in earlier studies cannot be completely ruled out, recent findings suggest a robust correlation between asbestos exposure and ovarian cancer. This highlights the importance of sustained efforts to minimize asbestos exposure and protect public health.

Pelvic inflammatory disease and risk of epithelial ovarian cancer: a national population-based case-control study in Sweden

BACKGROUND

Epithelial ovarian cancer is an insidious disease, and women are often diagnosed when the disease is beyond curative treatment. Accordingly, identifying modifiable risk factors is of paramount importance. Inflammation predisposes an individual to cancer in various organs, but whether pelvic inflammatory disease is associated with an increased risk of epithelial ovarian cancer has not been fully determined.

OBJECTIVE

This study aimed to investigate a possible association between clinically verified pelvic inflammatory disease and the risk of epithelial ovarian cancer.

STUDY DESIGN

In this national population-based case-control study, all women in Sweden diagnosed with epithelial ovarian cancer between 1999 and 2020 and 10 controls for each were identified, matched for age and residential district. Using several Swedish nationwide registers, data on previous pelvic inflammatory disease and potential confounding factors (age, parity, educational level, and previous gynecologic surgery) were retrieved. Adjusted odds ratios and 95% confidence intervals were estimated using conditional logistic regression. Histotype-specific analyses were performed for the subgroup of women diagnosed with epithelial ovarian cancer between 2015 and 2020. Moreover, hormonal contraceptives and menopausal hormone therapy were adjusted in addition to the aforementioned confounders.

RESULTS

This study included 15,072 women with epithelial ovarian cancer and 141,322 controls. Most women (9102 [60.4%]) had serous carcinoma. In a subgroup of cases diagnosed between 2015 and 2020, high-grade serous carcinoma (2319 [60.0%]) was identified. A total of 168 cases (1.1%) and 1270 controls (0.9%) were diagnosed with pelvic inflammatory disease. Previous pelvic inflammatory disease was associated with an increased risk of epithelial ovarian cancer (adjusted odds ratio, 1.39; 95% confidence interval, 1.17-1.66) and serous carcinoma (adjusted odds ratio, 1.46; 95% confidence interval, 1.18-1.80) for the entire study population. For the subgroup of women diagnosed in 2015-2020, pelvic inflammatory disease was associated with high-grade serous carcinoma (adjusted odds ratio, 1.43; 95% confidence interval, 1.01-2.04). The odds ratios of the other histotypes were as follows: endometrioid (adjusted odds ratio, 0.13; 95% confidence interval, 0.02-1.06), mucinous (adjusted odds ratio, 1.55; 95% confidence interval, 0.56-4.29), and clear cell carcinoma (adjusted odds ratio, 2.30; 95% confidence interval, 0.90-5.86). A dose-response relationship was observed between the number of pelvic inflammatory disease episodes and the risk of epithelial ovarian cancer (Ptrend<.001).

CONCLUSION

A history of pelvic inflammatory disease is associated with an increased risk of epithelial ovarian cancer and a dose-response relationship is evident. Histotype-specific analyses show an association with increased risk of serous epithelial ovarian cancer and high-grade serous carcinoma and potentially also with clear cell carcinoma, but there is no significant association with other histotypes. Infection and inflammation of the upper reproductive tract might have serious long-term consequences, including epithelial ovarian cancer.

The Upper Reproductive System Microbiome: Evidence beyond the Uterus

The microbiome of the female upper reproductive system has garnered increasing recognition and has become an area of interest in the study of women's health. This intricate ecosystem encompasses a diverse consortium of microorganisms (i.e., microbiota) and their genomes (i.e., microbiome) residing in the female upper reproductive system, including the uterus, the fallopian tubes, and ovaries. In recent years, remarkable advancements have been witnessed in sequencing technologies and microbiome research, indicating the potential importance of the microbial composition within these anatomical sites and its impact in women's reproductive health and overall well-being. Understanding the composition, dynamics, and functions of the microbiome of the female upper reproductive system opens up exciting avenues for improving fertility, treating gynecological conditions, and advancing our comprehension of the intricate interplay between the microbiome and the female reproductive system. The aim of this study is to compile currently available information on the microbial composition of the female upper reproductive system in humans, with a focus beyond the uterus, which has received more attention in recent microbiome studies compared with the fallopian tubes and ovaries. In conclusion, this review underscores the potential role of this microbiome in women's physiology, both in health and disease.

Trinity of inflammation, innate immune cells and cross-talk of signalling pathways in tumour microenvironment

Unresolved inflammation is a pathological consequence of persistent inflammatory stimulus and perturbation in regulatory mechanisms. It increases the risk of tumour development and orchestrates all stages of tumorigenesis in selected organs. In certain cancers, inflammatory processes create the appropriate conditions for neoplastic transformation. While in other types, oncogenic changes pave the way for an inflammatory microenvironment that leads to tumour development. Of interest, hallmarks of tumour-promoting and cancer-associated inflammation are striking similar, sharing a complex network of stromal (fibroblasts and vascular cells) and inflammatory immune cells that collectively form the tumour microenvironment (TME). The cross-talks of signalling pathways initially developed to support homeostasis, change their role, and promote atypical proliferation, survival, angiogenesis, and subversion of adaptive immunity in TME. These transcriptional and regulatory pathways invariably contribute to cancer-promoting inflammation in chronic inflammatory disorders and foster "smouldering" inflammation in the microenvironment of various tumour types. Besides identifying common target sites of numerous cancer types, signalling programs and their cross-talks governing immune cells' plasticity and functional diversity can be used to develop new fate-mapping and lineage-tracing mechanisms. Here, we review the vital molecular mechanisms and pathways that establish the connection between inflammation and tumour development, progression, and metastasis. We also discussed the cross-talks between signalling pathways and devised strategies focusing on these interaction mechanisms to harness synthetic lethal drug combinations for targeted cancer therapy.

The Female Reproductive Tract Microbiome and Cancerogenesis: A Review Story of Bacteria, Hormones, and Disease

The microbiota is the complex community of microorganisms that populate a particular environment in the human body, whereas the microbiome is defined by the entire habitat-microorganisms and their environment. The most abundant and, therefore, the most studied microbiome is that of the gastrointestinal tract. However, the microbiome of the female reproductive tract is an interesting research avenue, and this article explores its role in disease development. The vagina is the reproductive organ that hosts the largest number of bacteria, with a healthy profile represented mainly by Lactobacillus spp. On the other hand, the female upper reproductive tract (uterus, Fallopian tubes, ovaries) contains only a very small number of bacteria. Previously considered sterile, recent studies have shown the presence of a small microbiota here, but there are still debates on whether this is a physiologic or pathologic occurrence. Of particular note is that estrogen levels significantly influence the composition of the microbiota of the female reproductive tract. More and more studies show a link between the microbiome of the female reproductive tract and the development of gynecological cancers. This article reviews some of these findings.

Frequency of Asbestos Exposure and Histological Subtype of Ovarian Carcinoma

The International Agency for Research on Cancer established a causal link between asbestos exposure and ovarian cancer. However, the exposure frequency and histological characteristics of asbestos-associated ovarian cancers remain to be investigated in detail. This multicenter case-case study assessed the asbestos exposure in ovarian carcinoma (OC) patients, alongside its association with histological subtype. Women were recruited in four hospitals in Lyon, France. Histological reports were reviewed by a pathologist. Patient and family members' data were collected by phone-based questionnaires. Asbestos exposure was defined as direct (occupational and environmental) and indirect (via parents, partners, and children). An industrial hygienist assessed the probability and level of exposure. The 254 enrolled patients (mean age 60 years) reported having an average of 2.3 different jobs (mean working duration 29 years). The prevalence of direct and indirect asbestos exposure was 13% (mean exposure duration 11 years) and 46%, respectively. High-grade serous carcinoma accounted for 73% of all OCs and 82% of histological subtypes in women with direct exposure. After adjustment on a familial history of OC, no significant associations between asbestos exposure (direct and/or indirect) and high-grade serous carcinoma were found. Women with OC had a high prevalence of asbestos exposure. Establishing risk profiles, as reported here, is important in facilitating compensation for asbestos-related OCs and for the surveillance of women at risk.

Different Influences of Endometriosis and Pelvic Inflammatory Disease on the Occurrence of Ovarian Cancer

To compare the rate and risk of ovarian cancer in patients with endometriosis or pelvic inflammatory disease (PID). A nationwide population cohort research compared the risk of ovarian cancer in 135,236 age-matched comparison females, 114,726 PID patients, and 20,510 endometriosis patients out of 982,495 females between 1 January 2002 and 31 December 2014 and ended on the date of confirmation of ovarian cancer, death, or 31 December 2014. In order to reduce the unbalanced characteristics, propensity score matching (PSM) was performed for 20,478 females in each subgroup. The incidence rate (per 100,000 person–years) of ovarian cancer was 8.74 (95% CI, 7.16–10.66) in comparison, 9.26 (7.54–11.39) in PID, and 28.73 (21.07–39.16) in endometriosis cohorts. The adjusted hazard ratio (aHR) of ovarian cancer was 1.17 (p = 0.296) in PID and 3.12 (p < 0.001) in endometriosis cohorts, compared with the comparison cohort in full cohort, using the multiple Cox regression model. The aHR of ovarian cancer was 0.83 (p = 0.650) in PID and 3.03 (p = 0.001) in endometriosis cohorts, compared with the comparison cohort after performing PSM. In the full cohort and PSM population, the cumulative incidence rate of ovarian cancer was significantly higher in patients with endometriosis than in those with PID or in the comparison cohort (p < 0.001 and p < 0.001). In conclusion, after considering the differences in the impacts of exposure to endometriosis or PID, patients with endometriosis were more likely to develop ovarian cancer.

Chlamydia trachomatis, Pelvic Inflammatory Disease, and Epithelial Ovarian Cancer

Epidemiologic, clinical, molecular and translational research findings support an interrelationship between Chlamydia trachomatis, pelvic inflammatory disease (PID), and epithelial ovarian cancer (EOC). Overall, the link between C. trachomatis, PID, and EOC seems to be relatively weak, although nondifferential misclassification bias may have attenuated the results. The predominant tubal origin of EOC and the role of chronic inflammation in tumorigenesis suggest that the association is biologically plausible. Thus, C. trachomatis and PID may represent potential risk factors or risk markers for EOC. However, many steps in this chain of events are still poorly understood and need to be addressed in future studies. Research gaps include time of exposure in relation to the long-term consequences and lag time to EOC. Data of differential risk for EOC between chlamydial and nonchlamydial PID is also needed. Another major research gap has been the absence of high-performance biomarkers for C. trachomatis, PID, and EOC, as well as EOC precursors. Biomarkers for C. trachomatis and PID leading to increased risk of EOC should be developed. If the association is confirmed, C. trachomatis and PID prevention efforts may play a role in reducing the burden of EOC.

The role of the microbiome in ovarian cancer: mechanistic insights into oncobiosis and to bacterial metabolite signaling

Ovarian cancer is characterized by dysbiosis, referred to as oncobiosis in neoplastic diseases. In ovarian cancer, oncobiosis was identified in numerous compartments, including the tumor tissue itself, the upper and lower female genital tract, serum, peritoneum, and the intestines. Colonization was linked to Gram-negative bacteria with high inflammatory potential. Local inflammation probably participates in the initiation and continuation of carcinogenesis. Furthermore, local bacterial colonies in the peritoneum may facilitate metastasis formation in ovarian cancer. Vaginal infections (e.g. Neisseria gonorrhoeae or Chlamydia trachomatis) increase the risk of developing ovarian cancer. Bacterial metabolites, produced by the healthy eubiome or the oncobiome, may exert autocrine, paracrine, and hormone-like effects, as was evidenced in breast cancer or pancreas adenocarcinoma. We discuss the possible involvement of lipopolysaccharides, lysophosphatides and tryptophan metabolites, as well as, short-chain fatty acids, secondary bile acids and polyamines in the carcinogenesis of ovarian cancer. We discuss the applicability of nutrients, antibiotics, and probiotics to harness the microbiome and support ovarian cancer therapy. The oncobiome and the most likely bacterial metabolites play vital roles in mediating the effectiveness of chemotherapy. Finally, we discuss the potential of oncobiotic changes as biomarkers for the diagnosis of ovarian cancer and microbial metabolites as possible adjuvant agents in therapy.

Moxibustion for treating chronic pelvic inflammatory disease: A protocol for systematic review and meta-analysis

BACKGROUND

Chronic pelvic inflammatory disease (CPID) is a difficult-to-treat gynaecological disorder, which has complex etiologies, among married women. In recent years, moxibustion has gradually shown its clinical advantages and been more and more widely used In China. The protocol is try to synthesize and assess the effectiveness and safety of moxibustion for patients with CPID.

METHODS

Seven databases as following: PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, WangFang Database, Chinese Scientific Journal Database, Chinese Biomedical Literatures Database will be searched from their inception to May 2020. No restrictions about language and status. Study selection, data collection, and quality assessment will be respectively conducted by 2 researchers. Based on the heterogeneity test results, the fixed-effects or random-effects model will be selected to synthesize data. The effective rate, Pelvic inflammatory mass diameter and Pelvic fluid depth will be the primary outcomes. Patient reported outcome scale, visual analog scale, C-reactive protein, transforming growth factor β1 =  transforming growth factor β, incidence of any adverse events will be the secondary outcomes. Revman 5.4 software will be implemented for data synthesis. Dichotomous data will be represented by risk ratio for efficacy and safety of CPID treated with moxibustion, while continuous data will be represented by mean difference with a 95% confidence interval.

RESULTS

The results of this study will be published in a peer-reviewed journal. This study will provide a comprehensive review of the available evidence for the treatment of moxibustion with CPID.

CONCLUSIONS

This study expects to provide high-quality, evidence-based recommendations on further treatment for clinical guidance of CPID.

TRIAL REGISTRATION NUMBER

CRD42020158744 in PROSPERO 2020.

Opportunities and Challenges of the Human Microbiome in Ovarian Cancer

Ovarian cancer is the most lethal malignancy among gynecological cancers worldwide. Most ovarian cancer patients are diagnosed at an advanced stage because of non-specific clinical symptoms. The human microbiome plays a crucial role in maintaining the normal physiological and pathological state of the body. With the development of technologies such as DNA and 16S rRNA sequencing, an increasing number of findings on the role of microbiome in cancers are being reported. Microbiome abnormalities are increasingly associated with diseases, including cancer development, and response to therapies. Some studies have shown the relationship between microbiome changes and ovarian cancer. However, the mechanisms underlying this relationship are not yet fully understood. Here, we summarize the key findings in this regard by focusing on estrogen metabolism and host recognition receptors in microorganisms and changes in the gut or pelvic microbiome in patients with ovarian cancer. We further discuss the potential of using the microbiome as a novel biomarker for cancers. We also highlight the possibility to use microorganisms as a treatment modality to enhance the immune system, activate anti-tumor response, mediate chemotherapy resistance, and ameliorate the adverse effects of the treatment.

[Follow-up and counselling after pelvic inflammatory disease: CNGOF and SPILF Pelvic Inflammatory Diseases Guidelines]

OBJECTIVES

To determine the procedures for follow-up and counselling of patients after pelvic inflammatory disease (PID).

METHODS

A search in the Cochrane database, PubMed, and Google was performed using keywords related to follow-up and PID to identify reports published between 1990 and 2018. All studies published in French and English relevant to the areas of focus were included. A level of evidence (LE) based on the quality of the data available was applied for each area of focus and used for the guidelines.

RESULTS

The rate of recurrent PID is 15 to 21%. They are related to a recurrent sexually transmitted infection (STI) in 20 to 34% of cases. Recurrence PID increase the risk of infertility and chronic pelvic pain (LE2). Follow-up is recommended after PID (grade C). The rate of patients lost to follow-up is around 40%. Follow-up is improved by personalized text message reminders (grade B). Vaginal sampling for detection of N. gonorrhoeae, C. trachomatis, (and M. genitalium) by nucleic acid amplification techniques is recommended 3 to 6 months after treatment of PID associated with STI to rule out possible reinfections (grade C). The use of condoms after PID associated with STI is recommended to reduce the risk of recurrences (grade C). The systematic use of contraceptive pills after PID is not recommended to prevent subsequent infertility and chronic pelvic pain. Vaginal sampling for microbiological diagnosis is recommended before the insertion of an intrauterine device (grade B). The risk of ectopic pregnancy is high in these women and must be kept in mind.

CONCLUSION

Patient counselling and microbiological testing after PID decrease the risk of STI and thus the recurrence of PID.

The Risk of Gynecologic and Urinary Tract Cancer with Pelvic Inflammatory Disease: A Population-Based Cohort Study

Purpose: The aim of the study was to determine the association between pelvic inflammatory disease (PID) and breast, colorectal, gynecologic and urinary tract cancer.

Methods: The source of data was a longitudinal dataset compiled by the Longitudinal Health Insurance Database 2000 (LHID2000) which was collected by the National Health Insurance program. Cases of PID, at least two outpatient visits and one admission, were diagnosed from 2000 to 2013. The data for controls, age matched women who were not diagnosed with PID from 2000 to 2013, were also obtained.

Results: A total of 47,333 PID cases and 189,332 for control group were included in the study. The ectopic pregnancy incidence rate (per 10000 person months) was 1.912 and 0.595 in the PID and control group, respectively; the rate ratio was 3.211 (confidence interval, CI = 2.931-3.519). There were significantly different in gynecologic cancers and urinary tract cancers between the PID and control group; the rate ratios (95% C.I.) were 1.903 (1.672-2.166) and 1.566 (1.211-2.025), respectively.

Conclusion: Our study found that PID was associated with increased risks of gynecologic and urinary tract cancer but not colorectal or breast cancer. The information may lead to a strategy for cancer prevention and a reasonable healthcare usage through understanding PID epidemiology and controlling the inflammatory responses.

Benign gynecologic conditions are associated with ovarian cancer risk in African-American women: a case-control study

BACKGROUND

The association between common benign gynecologic conditions and ovarian cancer remains under-studied in African Americans. Therefore, we examine the association between self-reported history of benign gynecologic conditions and epithelial ovarian cancer risk in African-American women.

METHODS

Data from a large population-based, multi-center case-control study of epithelial ovarian cancer in African-American women were analyzed to estimate the association between self-reported history of endometriosis, pelvic inflammatory disease (PID), fibroid, and ovarian cyst with epithelial ovarian cancer. Logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (CI) for the associations between individual and composite gynecologic conditions and ovarian cancer.

RESULTS

600 cases and 752 controls enrolled in the African American Cancer Epidemiology Study between 1 December 2010 and 31 December 2015 comprised the study population. After adjusting for potential confounders, a history of endometriosis was associated with ovarian cancer (OR 1.78; 95% CI 1.09-2.90). A non-significant association of similar magnitude was observed with PID (OR 1.33; 95% CI 0.82-2.16), while no association was observed in women with a history of fibroid or ovarian cyst. A positive trend was observed for an increasing number of reported gynecologic conditions (p = 0.006) with consistency across histologic subtypes and among both oral contraceptive users and non-users.

CONCLUSION

A self-reported history of endometriosis among African-American women was associated with increased risk of ovarian cancer. Having multiple benign gynecologic conditions also increased ovarian cancer risk.

Poly (I:C) and LPS induce distinct immune responses by ovarian stromal fibroblasts

Despite its anatomical location, the ovary is a site of pathogen exposure in the human female reproductive tract (FRT). However, the role of ovarian stromal fibroblasts in immune protection is unclear. We generated a population of ovarian stromal fibroblasts derived from normal human ovaries that expressed the pattern recognition receptors TLR3, TLR4, RIG-I, & MDA5. Poly (I:C) and LPS, respective mimics of viral and bacterial infections, selectively upregulated antiviral gene expression and secretion of chemokines and antimicrobials. Poly (I:C) exclusively stimulated the expression of interferon (IFN) β, IFNλ1, and the IFN-stimulated gene OAS2. Poly (I:C) also significantly increased secretion of elafin, CCL20, and RANTES, but had no effect on SDF-1α. In contrast, LPS had no effect on IFN or ISG expression but significantly increased secretion of RANTES and SDF-1α. Secretions from poly (I:C)-treated fibroblasts had both greater anti-HIV activity and induced higher levels of CD4 + T cell chemotaxis than those from LPS-treated cells. Our studies demonstrate a potential key role for ovarian fibroblasts in innate immune protection against incoming pathogens in the normal ovary.

Mesenchymal Stem Cells in Restoration of Fertility at Experimental Pelvic Inflammatory Disease

Inflammatory disorders account for a significant percentage of gynecologic diseases, particularly in women of reproductive age. It is known that stem cells have anti-inflammatory and regenerative properties. Based on this, we investigated the effect of intravenous administration of cryopreserved mesenchymal stem cells (cMSCs) of bone marrow on experimental chronic inflammation of the ovaries. The paper shows that on the 21st day after cMSC therapy, leukocyte infiltration of ovaries was slightly relative to the control group without treatment, and the ratio of developing and atretic follicles in the animals with cMSC injection dramatically increased, while in the control, it still remained on the side of atretic forms. The number of apoptotic oocytes after stimulation of superovulation in the control group was significantly higher (85.3 ± 5.2%) than that in the animals with therapy (5.7 ± 0.8%). Relative number of fertilized eggs in the group with cMSC therapy was higher by 40% compare to that in the control. Pregnancy rate in natural estrous cycle after cell administration increased by 20%, and average number of litters in this group was two times significantly higher than that in the control. So the intravenous injection of cMSCs has the restorative effect on the fertility at experimental pelvic inflammatory disease.

The potential role of infectious agents and pelvic inflammatory disease in ovarian carcinogenesis

Background

The etiological cause of ovarian cancer is poorly understood. It has been theorized that bacterial or viral infection as well as pelvic inflammatory disease could play a role in ovarian carcinogenesis.

Aim

To review the literature on studies examining the association between ovarian cancer and bacterial or viral infection or pelvic inflammatory disease.

Methods

Database search through MEDLINE, applying the medical subject headings: “Ovarian neoplasms”, AND “Chlamydia infections”, “Neisseria gonorrhoeae”, “Mycoplasma genitalium”, “Papillomaviridae”, or “pelvic inflammatory disease”. Corresponding searches were performed in EMBASE, and Web of Science. The literature search identified 935 articles of which 40 were eligible for inclusion in this review.

Results

Seven studies examined the association between bacterial infection and ovarian cancer. A single study found a significant association between chlamydial infection and ovarian cancer, while another study identified Mycoplasma genitalium in a large proportion of ovarian cancer cases. The remaining studies found no association. Human papillomavirus detection rates varied from 0 to 67% and were generally higher in the Asian studies than in studies from Western countries. Cytomegalovirus was the only other virus to be detected and was found in 50% of cases in a case-control study. The association between ovarian cancer and pelvic inflammatory disease was examined in seven epidemiological studies, two of which, reported a statistically significant association.

Conclusions

Data indicate a potential association between pelvic inflammatory disease and ovarian cancer. An association between ovarian cancer and high-risk human papillomavirus genotypes may exist in Asia, whereas an association in Western countries seems unlikely due to the low reported prevalence. Potential carcinogenic bacteria were found, but results were inconsistent, and further research is warranted.

Electronic supplementary material

The online version of this article (doi:10.1186/s13027-017-0134-9) contains supplementary material, which is available to authorized users.

Epidemiology of ovarian cancer: a review

Ovarian cancer (OC) is the seventh most commonly diagnosed cancer among women in the world and the tenth most common in China. Epithelial OC is the most predominant pathologic subtype, with five major histotypes that differ in origination, pathogenesis, molecular alterations, risk factors, and prognosis. Genetic susceptibility is manifested by rare inherited mutations with high to moderate penetrance. Genome-wide association studies have additionally identified 29 common susceptibility alleles for OC, including 14 subtype-specific alleles. Several reproductive and hormonal factors may lower risk, including parity, oral contraceptive use, and lactation, while others such as older age at menopause and hormone replacement therapy confer increased risks. These associations differ by histotype, especially for mucinous OC, likely reflecting differences in etiology. Endometrioid and clear cell OC share a similar, unique pattern of associations with increased risks among women with endometriosis and decreased risks associated with tubal ligation. OC risks associated with other gynecological conditions and procedures, such as hysterectomy, pelvic inflammatory disease, and polycystic ovarian syndrome, are less clear. Other possible risk factors include environmental and lifestyle factors such as asbestos and talc powder exposures, and cigarette smoking. The epidemiology provides clues on etiology, primary prevention, early detection, and possibly even therapeutic strategies.

Epidemiology of ovarian cancer: a review

Ovarian cancer (OC) is the seventh most commonly diagnosed cancer among women in the world and the tenth most common in China. Epithelial OC is the most predominant pathologic subtype, with five major histotypes that differ in origination, pathogenesis, molecular alterations, risk factors, and prognosis. Genetic susceptibility is manifested by rare inherited mutations with high to moderate penetrance. Genome-wide association studies have additionally identified 29 common susceptibility alleles for OC, including 14 subtype-specific alleles. Several reproductive and hormonal factors may lower risk, including parity, oral contraceptive use, and lactation, while others such as older age at menopause and hormone replacement therapy confer increased risks. These associations differ by histotype, especially for mucinous OC, likely reflecting differences in etiology. Endometrioid and clear cell OC share a similar, unique pattern of associations with increased risks among women with endometriosis and decreased risks associated with tubal ligation. OC risks associated with other gynecological conditions and procedures, such as hysterectomy, pelvic inflammatory disease, and polycystic ovarian syndrome, are less clear. Other possible risk factors include environmental and lifestyle factors such as asbestos and talc powder exposures, and cigarette smoking. The epidemiology provides clues on etiology, primary prevention, early detection, and possibly even therapeutic strategies.

Pelvic inflammatory disease and the risk of ovarian cancer: a meta-analysis

PURPOSE

Previous studies on pelvic inflammatory disease (PID) and the risk of ovarian cancer have found inconsistent results. We performed an updated meta-analysis to summarize the evidence of this association.

METHODS

PubMed, Embase, and ISI web of science databases were searched through October 2016 for studies that investigated the PID and ovarian cancer association. Summary risk estimates were calculated using random-effects meta-analysis.

RESULT

Thirteen studies were eligible for analysis, which included six cohort studies and seven case-control studies. PID was associated with an increased risk of ovarian cancer overall [relative risk (RR) 1.24, 95% CI 1.06-1.44; I ²  = 58.8%]. In analyses stratified by race, a significant positive association was observed in studies conducted among Asian women (RR 1.69, 95% CI 1.22-2.34; I ²  = 0%), but marginally significant among Caucasians (RR 1.18, 95% CI 1.00-1.39; I ²  = 60.7%).Risk estimates were elevated in both cohort (RR1.32; 95% CI 1.05-1.66; I ²  = 64.7%) and case-control studies (RR 1.17; 95% CI 0.93-1.49; I ²  = 57.6%), albeit not statistically significant in case-control studies.

CONCLUSIONS

Our results suggested that PID might be a potential risk factor of ovarian cancer, with pronounced associations among Asian women. Large and well-designed studies with objective assessment methods, such as hospital records, are needed to confirm the findings of this meta-analysis.

Pelvic Inflammatory Disease and the Risk of Ovarian Cancer and Borderline Ovarian Tumors: A Pooled Analysis of 13 Case-Control Studies

Inflammation has been implicated in ovarian carcinogenesis. However, studies investigating the association between pelvic inflammatory disease (PID) and ovarian cancer risk are few and inconsistent. We investigated the association between PID and the risk of epithelial ovarian cancer according to tumor behavior and histotype. We pooled data from 13 case-control studies, conducted between 1989 and 2009, from the Ovarian Cancer Association Consortium (OCAC), including 9,162 women with ovarian cancers, 2,354 women with borderline tumors, and 14,736 control participants. Study-specific odds ratios were estimated and subsequently combined into a pooled odds ratio using a random-effects model. A history of PID was associated with an increased risk of borderline tumors (pooled odds ratio (pOR) = 1.32, 95% confidence interval (CI): 1.10, 1.58). Women with at least 2 episodes of PID had a 2-fold increased risk of borderline tumors (pOR = 2.14, 95% CI: 1.08, 4.24). No association was observed between PID and ovarian cancer risk overall (pOR = 0.99, 95% CI: 0.83, 1.19); however, a statistically nonsignificantly increased risk of low-grade serous tumors (pOR = 1.48, 95% CI: 0.92, 2.38) was noted. In conclusion, PID was associated with an increased risk of borderline ovarian tumors, particularly among women who had had multiple episodes of PID. Although our results indicated a histotype-specific association with PID, the association of PID with ovarian cancer risk is still somewhat uncertain and requires further investigation.

Epidemiology of ovarian cancer: a review

Ovarian cancer (OC) is the seventh most commonly diagnosed cancer among women in the world and the tenth most common in China. Epithelial OC is the most predominant pathologic subtype, with five major histotypes that differ in origination, pathogenesis, molecular alterations, risk factors, and prognosis. Genetic susceptibility is manifested by rare inherited mutations with high to moderate penetrance. Genome-wide association studies have additionally identified 29 common susceptibility alleles for OC, including 14 subtype-specific alleles. Several reproductive and hormonal factors may lower risk, including parity, oral contraceptive use, and lactation, while others such as older age at menopause and hormone replacement therapy confer increased risks. These associations differ by histotype, especially for mucinous OC, likely reflecting differences in etiology. Endometrioid and clear cell OC share a similar, unique pattern of associations with increased risks among women with endometriosis and decreased risks associated with tubal ligation. OC risks associated with other gynecological conditions and procedures, such as hysterectomy, pelvic inflammatory disease, and polycystic ovarian syndrome, are less clear. Other possible risk factors include environmental and lifestyle factors such as asbestos and talc powder exposures, and cigarette smoking. The epidemiology provides clues on etiology, primary prevention, early detection, and possibly even therapeutic strategies.

Is Pelvic Inflammatory Disease a Risk Factor for Ovarian Cancer?

BACKGROUND

Pelvic inflammatory disease (PID) has been proposed as a risk factor for ovarian cancer. However, the existing literature on the association between PID and ovarian cancer risk is inconclusive, and only few cohort studies have been conducted.

METHODS

Using nationwide Danish registries, we conducted a population-based cohort study including all women from the birth cohorts 1940 to 1970 in Denmark during 1978-2012 (n = 1,318,929) to investigate the association between PID and subsequent risk of epithelial ovarian cancer. Among women in the cohort, 81,281 women were diagnosed with PID and 5,356 women developed ovarian cancer during follow-up through 2012. Cox regression models were used to estimate HRs and 95% confidence intervals (CI) for the association between PID and ovarian cancer, both overall and according to histotype.

RESULTS

For ovarian cancer overall, we observed no association with PID (HR, 1.05; 95% CI, 0.92-1.20). However, in histotype-specific analyses, we found a statistically significantly increased risk of serous ovarian cancer among women with PID (HR, 1.19; 1.00-1.41; P = 0.047). Conversely, PID was not convincingly associated with risk of any of the other histotypes of ovarian cancer.

CONCLUSIONS

PID was associated with a modestly increased risk of serous ovarian cancer, but not other histotypes.

IMPACT

Our results indicate that PID is not a strong risk factor for ovarian cancer. Whether PID is slightly associated with risk of serous ovarian cancer has to be confirmed in other studies. Cancer Epidemiol Biomarkers Prev; 26(1); 104-9. ©2016 AACR.

Increased risk of borderline ovarian tumors in women with a history of pelvic inflammatory disease: A nationwide population-based cohort study

OBJECTIVE

Some studies suggest that pelvic inflammatory disease (PID) is a potential risk factor for ovarian cancer. However, only few studies have investigated the association between PID and risk of borderline ovarian tumors. We conducted a population-based cohort study to investigate the association between PID and risk of borderline ovarian tumors.

METHODS

Using various nationwide Danish registries we identified all women in Denmark during 1978-2012, who were born during 1940-1970 (n=1,318,925). Of these, 81,263 women were diagnosed with PID in the study period, and 2736 women had a borderline ovarian tumor (1290 serous and 1344 mucinous). Hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between PID and risk of borderline tumors were estimated using Cox regression models with adjustment for potential confounders.

RESULTS

A history of PID was associated with an increased risk of borderline ovarian tumors (HR=1.39; 95% CI: 1.19-1.61). However, histotype-specific analyses revealed significant variation in risk as PID was only associated with an increased risk of serous borderline tumors (HR=1.85; 95% CI: 1.52-2.24), but not with mucinous borderline tumors (HR=1.06; 95% CI: 0.83-1.35).

CONCLUSIONS

PID is associated with an increased risk of serous borderline tumors. Further research on the potential underlying biological mechanisms and on the identification of the subset of women with PID who are at increased risk of serous borderline tumors is warranted.

High-risk HPV is not associated with epithelial ovarian cancer in a Caucasian population

Background

High-risk human papillomavirus (HPV) has been suspected to play a role in the carcinogenesis of epithelial ovarian cancer (EOC). However, results from previous studies are conflicting. In most of these studies, the number of tissue samples was small. The current study was therefore undertaken to examine the prevalence of high-risk HPV DNA in EOC in a large series of patients.

Method

Formalin-fixed, paraffin-imbedded tumor tissue samples from 198 cases consecutively included in the Danish Pelvic Mass Study were analyzed. The material included 163 serous adenocarcinomas, 15 endometrioid adenocarcinomas, 11 mucinous adenocarcinomas and nine clear-cell carcinomas. Genotyping for high-risk HPV DNA was performed by real-time Polymerase chain reaction (PCR) using an in-house TaqMan singleplex assay targeting the E6/E7 region of the HPV 16 and 18 genomes. Additionally, 20 random samples without HPV 16 and/or 18 infections were reanalyzed for HPV subtypes 31, 33, 35, 39, 45, 51 and 52.

Results

The quality criteria were fulfilled in 191 samples. HPV 18 DNA was detected in one sample only, while the rest tested negative. The subgroup analysis for seven additional high-risk HPV subtypes was also negative.

Conclusions

Only one in 191 samples was positive for HPV DNA. We therefore conclude that high risk HPV is unlikely to be associated with EOC in a Caucasian population. Future studies should focus on other microorganisms as possible etiological factors in EOC carcinogenesis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13027-016-0087-4) contains supplementary material, which is available to authorized users.

BRCA1 185delAG Mutation Enhances Interleukin-1β Expression in Ovarian Surface Epithelial Cells

Familial history remains the strongest risk factor for developing ovarian cancer (OC) and is associated with germline BRCA1 mutations, such as the 185delAG founder mutation. We sought to determine whether normal human ovarian surface epithelial (OSE) cells expressing the BRCA1 185delAG mutant, BRAT, could promote an inflammatory phenotype by investigating its impact on expression of the proinflammatory cytokine, Interleukin-1β (IL-1β). Cultured OSE cells with and without BRAT were analyzed for differential target gene expression by real-time PCR, western blot, ELISA, luciferase reporter, and siRNA assays. We found that BRAT cells expressed increased cellular and secreted levels of active IL-1β. BRAT-expressing OSE cells exhibited 3-fold enhanced IL-1β mRNA expression, transcriptionally regulated, in part, through CREB sites within the (−1800) to (−900) region of its promoter. In addition to transcriptional regulation, BRAT-mediated IL-1β expression appears dualistic through enhanced inflammasome-mediated caspase-1 cleavage and activation of IL-1β. Further investigation is warranted to elucidate the molecular mechanism(s) of BRAT-mediated IL-1β expression since increased IL-1β expression may represent an early step contributing to OC.

Pelvic inflammation and the pathogenesis of ovarian cancer: a cohort study

OBJECTIVE

The aim of this study was to determine whether pelvic inflammation contributes to the pathogenesis of ovarian cancer or other malignancies.

DESIGN

This article is a cohort study.

SETTING

The study was conducted in a tertiary university and provincial cancer referral institutions.

POPULATION SAMPLE

The population sample was composed of women referred for fertility surgery and women diagnosed with ovarian cancer in British Columbia.

METHODS

We conducted a cohort study using prospectively collected data on fertility surgery patients. Eight hundred eighty-eight women with past pelvic inflammation, as diagnosed by characteristic findings at fertility surgery, and 552 women without were compared for the subsequent development of malignancy, during the period of 1981 to 2012. Logistic regression was used to estimate adjusted odds ratios and 95% confidence intervals. Standardized incidence ratios were also calculated using age-specific cancer incidence rates among all women in British Columbia.

RESULTS

The adjusted odds ratio for ovarian cancer, after past inflammation, was 5.56 (95% confidence interval, 0.52-59.40). Age-adjusted ovarian cancer incidence was significantly elevated among women with previous pelvic inflammation (standardized incidence ratio, 3.99; 95% confidence interval, 1.46-8.68). The rates of other malignancies were similar in both cohorts.

CONCLUSION

The rate of ovarian cancer was not significantly elevated in women with past pelvic inflammation compared with the controls. However, a significantly increased risk for ovarian cancer was apparent among women with pelvic inflammation when compared with the general population. Pelvic inflammation may be a contributory factor in the pathogenesis of ovarian cancer.

Acupuncture for chronic pelvic inflammatory disease: a qualitative study of patients' insistence on treatment

Background

Acupuncture is an effective complement to pharmacological therapy in the alleviation of chronic pelvic inflammatory disease (PID). It has mild or no side effects; however, a minimum of 3 months of therapy is required to guarantee a beneficial outcome. This study investigates why patients insist on acupuncture therapy to aid recuperation.

Methods

The study included a purposive sample of 15 participants diagnosed with chronic PID who had received a course of acupuncture therapy at least twice a week for a minimum of 3 months. Semi-structured interviews were conducted, recorded, transcribed, coded and analyzed using systematic text condensation.

Results

Four overarching themes were identified from the participants’ reasons for insisting on lengthy, but in their view important, acupuncture courses. The four overarching themes were: (1) the patients’ characteristics, including pregnancy aspiration and the fear of serious gynecological disease; (2) the patient–practitioner relationship, including the acupuncturist’s attitude towards the patients and the explanation of the disease from a traditional Chinese medicine (TCM) perspective; (3) the characteristics of acupuncture, including the diversification of treatment modes, the synthetical effect, and no side-effects; and (4) the clinical environment, including the exchange of experience between patients and the well-equipped setting.

Conclusions

There were mixed reasons for patients diagnosed with chronic PID maintaining acupuncture treatments. Knowledge and understanding about the acupuncture-disease relationship were conducive to the patients’ preference for acupuncture. Acupuncture as a complement to Western medicine should be further developed while maintaining these positive features. Participants reported feeling hope, confidence, and a sense of responsibility for their treatment during the process, although the treatments did not always have the expected outcome.

Primary fallopian tube carcinoma arising in the setting of chronic pelvic inflammatory disease

Primary fallopian tube cancer (PFTC) is a rare gynaecological malignancy, clinically often mistaken for pelvic inflammatory disease or ovarian cancer. Three primary fallopian tube carcinomas, arising in a background of chronic pelvic inflammatory disease (PID), are presented. The possible association between chronic PID and PFTC is discussed and a hypothesies linking these cancers with chronic inflammation is proposed.