Use of fertility drugs and risk of ovarian cancer: Danish Population Based Cohort Study

Risk of borderline ovarian tumors after fertility treatment - Results from a Danish cohort of infertile women

OBJECTIVE

Results from previous studies examining the association between fertility treatment and borderline ovarian tumors are inconsistent. The aim of this study was to investigate the association between fertility treatment and borderline ovarian tumors in a cohort of infertile women.

METHODS

This cohort study was based on the Danish Infertility Cohort and included all infertile women aged 20-45 years living in Denmark between 1 January 1995 and 31 December 2017 (n = 146,891). Information on use of fertility drugs, borderline ovarian tumors and cancer diagnoses, covariates, emigration, and vital status was obtained by linkage to national registers. Cox proportional hazard models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) with adjustment for potential confounders for overall borderline ovarian tumors and for serous- and mucinous borderline ovarian tumors separately.

RESULTS

During a median 11.3 years of follow-up, 144 women developed a borderline ovarian tumor. No marked associations between ever use of clomiphene citrate, gonadotropins, gonadotropin-releasing hormone receptor modulators, human chorionic gonadotropin or progesterone and borderline ovarian tumors were observed, neither overall nor for serous and mucinous borderline ovarian tumors analysed separately. Further, no clear associations with borderline ovarian tumors were found according to cumulative dose, time since first use or parity status for any fertility drugs.

CONCLUSIONS

No marked associations between use of fertility drugs and borderline ovarian tumors were observed. However, the cohort's relatively young age at end of follow-up emphasizes the importance of extending the follow-up period for women who have used fertility drugs.

The pregnancy and oncology outcome of fertility-sparing management for synchronous primary neoplasm of endometrium and ovary

PURPOSE

To investigate the efficacy of fertility-preserving treatment for young women with synchronous primary neoplasm of endometrium and ovary.

METHODS

We retrospectively reviewed eight patients with concurrent primary grade 1 presumed stage IA endometrioid endometrial adenocarcinoma (EEA) or endometrial atypical hyperplasia (EAH) and primary stage I ovarian tumors who underwent fertility-sparing treatment in the Obstetrics and Gynecology Hospital of Fudan University between April 2016 and December 2022.

RESULTS

Synchronous endometrial and ovarian cancers (SEOC) accounted for 50% of these eight patients. The median age of patients was 30.5 years (range, 28-34 years). None of them received chemotherapy. The median treatment time was 4 months (range, 3-8 months). 87.5% (7/8) cases achieved complete response (CR), and the median time to CR was 3.8 months (range, 1.5-7.7 months). Among patients who got CR, none of them showed any signs of recurrence. Pregnancies and successful deliveries were achieved in 4 of 5 patients. Till September 2023, the median follow-up period was 50.5 months (range:15.2-85.2 months).

CONCLUSION

Fertility-sparing treatment is feasible for highly selected patients with synchronous neoplasm of the endometrium and ovary, but strict screening and monitoring are mandatory. Though the results of our limited cases are encouraging, long follow-up and more clinical data are required. Enrolled patients must be fully informed of the risks during conservative treatment.

Effects of Infertility Drug Exposure on the Risk of Borderline Ovarian Tumors: A Systematic Review and Meta-Analysis

Whether infertility drug exposure increases the risk of borderline ovarian tumors (BOTs) remains controversial. The present study was conducted with a comprehensive search for studies published from January 1990 to December 2021 in the online databases Cochrane Library, PubMed, Web of Science and EMBASE. We considered the first diagnosis of a BOT as the primary outcome. The odds ratio (OR) was calculated with corresponding 95% confidence intervals (CIs) for the risk of BOTs in patients who were treated with infertility drugs. Ten studies, a total of 2,779,511 women, qualified for inclusion in this meta-analysis. The pooled OR of 1.56 (95% CI: 1.09-2.22) revealed a significant positive association between infertility drugs and an increased risk for BOTs, but for specific drugs, only CC plus Gn had statistical significance. No publication bias was detected using the Egger and Begg tests (p > 0.05). A significant difference in BOT incidence was observed among infertile women and nulliparous women who were treated with or without infertility drugs. In conclusion, the use of infertility drugs may increase the risk of BOTs, but a dose-dependent relationship was not observed between the number of assisted reproduction technology cycles and the risk of BOTs, and infertile women who successfully became pregnant might have a reduced risk. Registration: PROSPERO, CRD42022330775.

Epidemiology and risk factors for ovarian cancer

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

Ovulation induction drug and ovarian cancer: an updated systematic review and meta-analysis

OBJECTIVE

To explore the association between ovulation induction drugs and ovarian cancer.

DESIGN

Systematic review and meta-analysis.

SETTING

Not applicable.

PATIENT(S)

Women without ovarian cancer who ever or never underwent ovarian induction.

INTERVENTION(S)

An extensive electronic search of the following databases was performed: PubMed, EMBASE, MEDLINE, Google Scholar, Cochrane Library and CNKI, from inception until January 2022. A total of 34 studies fulfilled our inclusion criteria and were included in the final meta-analysis. The odds ratio (OR) and random-effects model were used to estimate the pooled effects. The Newcastle-Ottawa Scale was used to assess the quality of included studies. Funnel plots and Egger tests were used to assess publication bias.

MAIN OUTCOMES

New diagnosed borderline ovarian tumor (BOT) and invasive ovarian cancer (IOC) between ovulation induction (OI) group and control (CT) group considering fertility outcome, OI cycles and specific OI drugs.

RESULTS

Primarily, there was no significant difference in the incidence of IOC and BOT between the OI and CT groups. Secondly, OI treatment did not increase the risk of IOC and BOT in the multiparous women, nor did it increase the risk of IOC in the nulliparous women. However, the risk of BOT appeared to be higher in nulliparous women treated with OI treatment. Thirdly, among women exposed to OI, the risk of IOC and BOT was higher in nulliparous women than in multiparous women. Fourthly, the risk of IOC did not increase with increasing OI cycles. Lastly, exposure to specific OI drugs also did not contribute to the risk of IOC and BOT.

CONCLUSION

Overall, OI treatment did not increase the risk of IOC and BOT in most women, regardless of OI drug type and OI cycle. However, nulliparous women treated with OI showed a higher risk of ovarian cancer, necessitating their rigorous monitoring and ongoing follow-up.

Fertility trends and comparisons in a historical cohort of US women with primary infertility

BACKGROUND

There is growing interest in long-term outcomes following infertility and infertility treatment. However, there are few detailed longitudinal cohorts available for this work. This study aimed to assemble a historical cohort of women with primary infertility and age-matched controls to evaluate fertility trends, sequelae, and sociodemographic differences. Described here are cohort group characteristics and associated reproductive trends over time.

METHODS

A population-based historical cohort was created using the Rochester Epidemiology Project (REP) record-linkage system (Olmsted County, MN). The cohort included women aged 18-50 with a diagnosis of primary infertility between January 1, 1980, and December 31, 1999. As part of a case-control study, we identified 1:1 age-matched female controls from the same community and era.

RESULTS

A total of 1001 women with primary infertility and 1001 age-matched controls were identified. The women with primary infertility were significantly more likely to be married, college educated, use barrier contraception, and non-smokers compared to age-matched controls. The incidence of primary infertility increased from 14 to 20 per 10,000 person years from 1980-1985 to 1995-1999. Ovulatory dysfunction and unexplained infertility were the most common causes of primary infertility and clomiphene was the most widely used fertility medication. Rates of in vitro fertilization (IVF) increased from 1.8% during 1980-1985 to 26.0% during 1995-1999.

CONCLUSION

Women with primary infertility were found to have unique sociodemographic characteristics compared to age-matched control women, which is consistent with previous research. The incidence of diagnosed primary infertility increased from 1980 to 1999, as did use of IVF.

Fertility treatment and cancers-the eternal conundrum: a systematic review and meta-analysis

STUDY QUESTION

Does fertility treatment (FT) significantly increase the incidence of breast, ovarian, endometrial or cervical cancer?

SUMMARY ANSWER

Overall, FT does not significantly increase the incidence of breast, ovarian or endometrial cancer and may even reduce the incidence of cervical cancer.

WHAT IS KNOWN ALREADY

Infertility affects more than 14% of couples. Infertility and nulliparity are established risk factors for endometrial, ovarian and breast cancer, yet the association with FT is more contentious.

STUDY DESIGN, SIZE, DURATION

A literature search was carried out using Cochrane Library, EMBASE, Medline and Google Scholar up to December 2019. Peer-reviewed studies stating cancer incidence (breast, ovarian, endometrial or cervical) in FT and no-FT groups were identified. Out of 128 studies identified, 29 retrospective studies fulfilled the criteria and were included (n = 21 070 337).

PARTICIPANTS/MATERIALS, SETTING, METHODS

In the final meta-analysis, 29 studies were included: breast (n = 19), ovarian (n = 19), endometrial (n = 15) and cervical (n = 13), 17 studies involved multiple cancer types and so were included in each individual cancer meta-analysis. Primary outcome of interest was cancer incidence (breast, ovarian, endometrial and cervical) in FT and no-FT groups. Secondary outcome was cancer incidence according to specific fertility drug exposure. Odds ratio (OR) and random effects model were used to demonstrate treatment effect and calculate pooled treatment effect, respectively. A meta-regression and eight sub-group analyses were performed to assess the impact of the following variables, maternal age, infertility, study size, outliers and specific FT sub-types, on cancer incidence.

MAIN RESULTS AND THE ROLE OF CHANCE

Cervical cancer incidence was significantly lower in the FT group compared with the no-FT group: OR 0.68 (95% CI 0.46-0.99). The incidences of breast (OR 0.86; 95% CI 0.73-1.01) and endometrial (OR 1.28; 95% CI 0.92-1.79) cancers were not found to be significantly different between the FT and no-FT groups. Whilst overall ovarian cancer incidence was not significantly different between the FT and no-FT groups (OR 1.19; 95% CI 0.98-1.46), separate analysis of borderline ovarian tumours (BOT) revealed a significant association (OR 1.69; 95% CI 1.27-2.25). In further sub-group analyses, ovarian cancer incidence was shown to be significantly higher in the IVF (OR 1.32; 95% CI 1.03-1.69) and clomiphene citrate (CC) treatment group (OR 1.40; 95% CI 1.10-1.77), respectively when compared with the no-FT group. Conversely, the incidences of breast (OR 0.75; 95% CI 0.61-0.92) and cervical cancer (OR 0.58; 95% CI 0.38-0.89) were significantly lower in the IVF treatment sub-group compared to the no-FT group.

LIMITATIONS, REASONS FOR CAUTION

The large, varied dataset spanning a wide study period introduced significant clinical heterogeneity. Thus, results have to be interpreted with an element of caution. Exclusion of non-English citations, unpublished work and abstracts, in order to ensure data accuracy and reliability was maintained, may have introduced a degree of selection bias.

WIDER IMPLICATIONS OF THE FINDINGS

The results for breast, ovarian, endometrial and cervical cancer are reassuring, in line with previously published meta-analyses for individual cancers but the association between IVF and CC treatment and an increase in ovarian cancer incidence requires additional work to understand the potential mechanism driving this association. In particular, focusing on (i) discriminating specific treatments effects from an inherent risk of malignancy; (ii) differential risk profiles among specific patient sub-groups (refractory treatment and obesity); and (iii) understanding the impact of FT outcomes on cancer incidence.

STUDY FUNDING/COMPETING INTEREST(S)

This study did not receive any funding. The authors have no financial, personal, intellectual and professional conflicts of interest to declare.

PROSPERO REGISTRATION NUMBER

CRD42019153404.

International trends in ovarian cancer incidence from 1973 to 2012

PURPOSE

Ovarian cancer is the 7th leading cancer diagnosis and the 8th leading cause of cancer death in women worldwide. We conducted this study to investigate the incidence of ovarian cancer internationally.

METHODS

The trends in ovarian cancer incidence were analyzed through the latest data of CI5 over the 40-year period from 21 populations in 4 continents using Joinpoint analysis, ASRs and proportions of different histological subtypes in those populations were also analyzed using volume XI of CI5.

RESULTS

ASRs of ovarian cancer were from 7.0 to 11.6 per 100,000 in non-Asia populations during 2008-2012. In Asia, the ASR in Israel (Jews) were the highest, up to 8.1 per 100,000 in the same period. The international trends from 1973 to 2012 showed that ASRs of ovarian cancer were decreasing in 8 of 21 selected populations, whereas ASRs in Slovakia, Spain (Navarra) and China (Shanghai) were increasing. Meanwhile, there are certain differences in the main pathological classification patterns within different regions. In Asia, China (Hong Kong) and Japan both have a higher ASRs and proportions for clear cell and endometrioid carcinomas, while Japan has the highest ASRs and proportions for mucinous carcinomas.

CONCLUSION

Although the reasons for those trends were not entirely clear, environmental, reproductive and genetic factors were likely to have led to these patterns. Meanwhile, more attention and further study should be given to the etiological factors of histology-specific ovarian cancer.

Factors influencing harmonized health data collection, sharing and linkage in Denmark and Switzerland: A systematic review

INTRODUCTION

The digitalization of medicine has led to a considerable growth of heterogeneous health datasets, which could improve healthcare research if integrated into the clinical life cycle. This process requires, amongst other things, the harmonization of these datasets, which is a prerequisite to improve their quality, re-usability and interoperability. However, there is a wide range of factors that either hinder or favor the harmonized collection, sharing and linkage of health data.

OBJECTIVE

This systematic review aims to identify barriers and facilitators to health data harmonization-including data sharing and linkage-by a comparative analysis of studies from Denmark and Switzerland.

METHODS

Publications from PubMed, Web of Science, EMBASE and CINAHL involving cross-institutional or cross-border collection, sharing or linkage of health data from Denmark or Switzerland were searched to identify the reported barriers and facilitators to data harmonization.

RESULTS

Of the 345 projects included, 240 were single-country and 105 were multinational studies. Regarding national projects, a Swiss study reported on average more barriers and facilitators than a Danish study. Barriers and facilitators of a technical nature were most frequently reported.

CONCLUSION

This systematic review gathered evidence from Denmark and Switzerland on barriers and facilitators concerning data harmonization, sharing and linkage. Barriers and facilitators were strictly interrelated with the national context where projects were carried out. Structural changes, such as legislation implemented at the national level, were mirrored in the projects. This underlines the impact of national strategies in the field of health data. Our findings also suggest that more openness and clarity in the reporting of both barriers and facilitators to data harmonization constitute a key element to promote the successful management of new projects using health data and the implementation of proper policies in this field. Our study findings are thus meaningful beyond these two countries.

Assisted reproductive technology treatment and risk of ovarian cancer—a nationwide population-based cohort study

STUDY QUESTION

Does hormone stimulation during assisted reproductive technology (ART) treatment increase the risk of ovarian cancer?

SUMMARY ANSWER

No increased risk of ovarian cancer was found among ART-treated women, with the exception of ART-treated women with endometriosis.

WHAT IS KNOWN ALREADY

Previous studies on the association between ovarian stimulation during ART and ovarian cancer have shown conflicting results. The risk of ovarian cancer varies according to the cause of infertility, and only a few studies on ART treatment and risk of ovarian cancer have had sufficient data to address this issue. Endometriosis has been linked to an increased risk of ovarian cancer.

STUDY DESIGN, SIZE, DURATION

Women undergoing ART treatment during 1994–2015 were registered in the Danish IVF register. Data were linked with data from the Danish Cancer Register and socio-demographic population registers using an individual person identification number assigned to people residing in Denmark.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All women undergoing ART treatment were age-matched with a random sample of the female background population and followed for up to 22 years. After relevant exclusions, the population consisted of 58 472 ART-treated women and 625 330 untreated women, all with no previous malignancies. Ovarian cancer risk was assessed using multivariable cox regression analyses with adjustment for educational level, marital status, parity and treatment year. Results are shown as hazard ratios (HRs) with corresponding CIs.

MAIN RESULTS AND THE ROLE OF CHANCE

In total, 393 (0.06%) women were diagnosed with ovarian cancer during follow-up (mean 9.7 years). Women treated with ART had an increased risk of ovarian cancer (HR 1.20, 95% CI 1.10–1.31), which diminished over time. The increased risk was apparent among women with female factor infertility (HR 1.36, 95% CI 1.25–1.48), whereas no female factor infertility was associated with a lower risk (HR 0.87, 95% CI 0.76–1.00). The risk was increased among women with endometriosis (HR 3.78, 95% CI 2.45–5.84), whereas no increased risk was found among ART-treated women with polycystic ovary syndrome, other female causes of infertility and unexplained infertility.

LIMITATIONS, REASONS FOR CAUTION

The association between ART treatment and ovarian cancer is likely influenced by increased detection due to multiple ultrasound scans during ART treatment.

WIDER IMPLICATIONS OF THE FINDINGS

Undergoing ART treatment without the presence of endometriosis was not associated with an increased risk of ovarian cancer, which is reassuring. Whether ART treatment increases the risk of ovarian cancer among women with endometriosis needs further investigation.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by a PhD grant to D.V. from the Faculty of Health and Medical Sciences, University of Copenhagen, Denmark. Funding for establishing the Danish National ART-couple II cohort was achieved from Ebba Rosa Hansen Foundation. The funders had no influence on data collection, analyses or results presented. The authors have no conflicts of interest to declare.

Risk of ovarian cancer in women treated with ovarian stimulating drugs for infertility

BACKGROUND

This is an updated version of the original Cochrane Review published in the Cochrane Library in 2013 (Issue 8) on the risk of ovarian cancer in women using infertility drugs when compared to the general population or to infertile women not treated. The link between fertility drugs and ovarian cancer remains controversial.

OBJECTIVES

To evaluate the risk of invasive ovarian cancer and borderline ovarian tumours in women treated with ovarian stimulating drugs for subfertility.

SEARCH METHODS

The original review included published and unpublished observational studies from 1990 to February 2013. For this update, we extended the searches from February 2013 to November 2018; we evaluated the quality of the included studies and judged the certainty of evidence by using the GRADE approach. We have reported the results in a Summary of findings table to present effect sizes across all outcome types.

SELECTION CRITERIA

In the original review and in this update, we searched for randomised controlled trials (RCTs) and non-randomised studies and case series including more than 30 participants.

DATA COLLECTION AND ANALYSIS

At least two review authors independently conducted eligibility and 'Risk of bias' assessments and extracted data. We grouped studies based on the fertility drug used for two outcomes: borderline ovarian tumours and invasive ovarian cancer. We conducted no meta-analyses due to expected methodological and clinical heterogeneity.

MAIN RESULTS

We included 13 case-control and 24 cohort studies (an additional nine new cohort and two case-control studies), which included a total of 4,684,724 women.Two cohort studies reported an increased incidence of invasive ovarian cancer in exposed subfertile women compared with unexposed women. One reported a standardised incidence ratio (SIR) of 1.19 (95% confidence interval (CI) 0.54 to 2.25) based on 17 cancer cases. The other cohort study reported a hazard ratio (HR) of 1.93 (95% CI 1.18 to 3.18), and this risk was increased in women remaining nulligravid after using clomiphene citrate (HR 2.49, 95% CI 1.30 to 4.78) versus multiparous women (HR 1.52, 95% CI 0.67 to 3.42) (very low-certainty evidence). The slight increase in ovarian cancer risk among women having between one and three cycles of in vitro fertilisation (IVF) was reported, but this was not clinically significant (P = 0.18). There was no increase in risk of invasive ovarian cancer after use of infertility drugs in women with the BRCA mutation according to one cohort and one case-control study. The certainty of evidence as assessed using GRADE was very low.For borderline ovarian tumours, one cohort study reported increased risk in exposed women with an SIR of 3.61 (95% CI 1.45 to 7.44), and this risk was greater after treatment with clomiphene citrate (SIR 7.47, 95% CI 1.54 to 21.83) based on 12 cases. In another cohort study, the risk of a borderline ovarian tumour was increased, with an HR of 4.23 (95% CI 1.25 to 14.33), for subfertile women treated with IVF compared with a non-IVF-treated group with more than one year of follow-up. A large cohort reported increased risk of borderline ovarian tumours, with HR of 2.46 (95% CI 1.20 to 5.04), and this was based on 17 cases. A significant increase in serous borderline ovarian tumours was reported in one cohort study after the use of progesterone for more than four cycles (risk ratio (RR) 2.63, 95% CI 1.04 to 6.64). A case-control study reported increased risk after clomiphene citrate was taken, with an SIR of 2.5 (95% CI 1.3 to 4.5) based on 11 cases, and another reported an increase especially after human menopausal gonadotrophin was taken (odds ratio (OR) 9.38, 95% CI 1.66 to 52.08). Another study estimated an increased risk of borderline ovarian tumour, but this estimation was based on four cases with no control reporting use of fertility drugs. The certainty of evidence as assessed using GRADE was very low.However, although some studies suggested a slight increase in risks of ovarian cancer and borderline ovarian tumour, none provided moderate- or high-certainty evidence, as summarised in the GRADE tables.

AUTHORS' CONCLUSIONS

Since the last version of this review, only a few new relevant studies have provided additional findings with supporting evidence to suggest that infertility drugs may increase the risk of ovarian cancer slightly in subfertile women treated with infertility drugs when compared to the general population or to subfertile women not treated. The risk is slightly higher in nulliparous than in multiparous women treated with infertility drugs, and for borderline ovarian tumours. However, few studies have been conducted, the number of cancers is very small, and information on the dose or type of fertility drugs used is insufficient.

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.

Do the Fertility Drugs Increase the Risk of Cancer? A Review Study

Aim: All over the world, many couples cannot conceive a child and have problems with pregnancy. Ovulation-inducing drugs are among the most important drugs used for the treatment of infertility. In recent years, there have been many debates about the relationship between fertility medication and cancer. Due to the lack of comprehensive study of this matter, and as understanding the relationship between the use of fertility drugs and cancer is of importance, the present study was conducted to investigate the relationship between infertility drugs and cancer in women. Materials and Methods: To determine the relationship between infertility treatment and cancer, a comprehensive search was carried out in databases such as; Medline, Web of Science Core Collection, and Scopus using keywords words; "infertility," "ovulation induction," "cancer," "infertility treatment," "ART," "tumor," "controlled ovarian stimulation," "fertility agents," and "neoplasms." Full-text, English language, and original articles were included in this study. Results: In total, 81 articles were entered into the study. The relationship between fertility medications and breast, ovary, endometrial, uterus, colon, thyroid, skin, cervical, and non-Hodgkin's lymphoma cancers were studied. Although the relationship between fertility medications and cancer is theoretically justifiable, most studies have shown that risk of cancer will not increase after fertility treatment. Conclusion: The results of this study did not show that fertility medications increase the risk of cancer among users. In summary, the relationship between infertility treatment and cancer incidence remains an open question.

Improved survival in ovarian cancer, with widening survival gaps of races and socioeconomic status: a period analysis, 1983-2012

Introduction: Ovarian cancer is the first leading cause of cancer-related deaths among gynecologic malignancies, and the 7th most common female cancer worldwide. However, previous studies on changes in the long-term survival of ovarian cancer were limited.

Methods: Our data were extracted from Surveillance, Epidemiology, and End Results (SEER) registries to assess the incidence and relative survival changes of patients with ovarian cancer during 1983-2012. Patients with ovarian cancer were stratified by age, race, and socioeconomic status (SES). Cox regression analysis and Spearman rank correlation analysis were performed by STATA 12 software.

Results: The overall incidence of ovarian cancer per 100,000 decreased from 13.7 to 12.4 to 10.8 over three decades with peak incidence occurring in the 70+ age group at 47.6, 45.7 and 40.2 in each respective decade. Median survival improved from 34 months to 46 months to 52 months over three decades, with the 5-year relative survival rate (RSR) increasing from 39.3% to 43.4% to 45.4% (p < 0.0001). However, Whites showed higher median survival (34 months) than Blacks (27 months) in the first decade, and the survival difference significantly increased to 16 months in the third decade. Additionally, the median survival difference between the low-poverty group and high poverty group increased from 4 months to 12 months in the three decades.

Discussion: This study demonstrated the decreasing incidence of ovarian cancer with an observed improvement in relative survival over three decades in a large sample. However, the survival gaps among races and SESs significantly widened over the three decades.

Risks of ovarian, breast, and corpus uteri cancer in women treated with assisted reproductive technology in Great Britain, 1991-2010: data linkage study including 2.2 million person years of observation

OBJECTIVE

To investigate the risks of ovarian, breast, and corpus uteri cancer in women who have had assisted reproduction.

DESIGN

Large, population based, data linkage cohort study.

SETTING AND PARTICIPANTS

All women who had assisted reproduction in Great Britain, 1991-2010, as recorded by the Human Fertilisation and Embryology Authority (HFEA).

INTERVENTIONS

HFEA fertility records for cohort members were linked to national cancer registrations.

MAIN OUTCOME MEASURES

Observed first diagnosis of ovarian, breast, and corpus uteri cancer in cohort members were compared with age, sex, and period specific expectation. Standardised incidence ratios (SIRs) were calculated by use of age, sex, and period specific national incidence rates.

RESULTS

255 786 women contributed 2 257 789 person years' follow-up. No significant increased risk of corpus uteri cancer (164 cancers observed v 146.9 cancers expected; SIR 1.12, 95% confidence interval 0.95 to 1.30) was found during an average of 8.8 years' follow-up. This study found no significantly increased risks of breast cancer overall (2578 v 2641.2; SIR 0.98, 0.94 to 1.01) or invasive breast cancer (2272 v 2371.4; SIR 0.96, 0.92 to 1.00). An increased risk of in situ breast cancer (291 v 253.5; SIR 1.15, 1.02 to 1.29; absolute excess risk (AER) 1.7 cases per 100 000 person years, 95% confidence interval 0.2 to 3.2) was detected, associated with an increasing number of treatment cycles (P=0.03). There was an increased risk of ovarian cancer (405 v 291.82; SIR 1.39, 1.26 to 1.53; AER 5.0 cases per 100 000 person years, 3.3 to 6.9), both invasive (264 v 188.1; SIR 1.40, 1.24 to 1.58; AER 3.4 cases per 100 000 person years, 2.0 to 4.9) and borderline (141 v 103.7; SIR 1.36, 1.15 to 1.60; AER 1.7 cases per 100 000 person years, 0.7 to 2.8). Increased risks of ovarian tumours were limited to women with endometriosis, low parity, or both. This study found no increased risk of any ovarian tumour in women treated because of only male factor or unexplained infertility.

CONCLUSIONS

No increased risk of corpus uteri or invasive breast cancer was detected in women who had had assisted reproduction, but increased risks of in situ breast cancer and invasive and borderline ovarian tumours were found in this study. Our results suggest that ovarian tumour risks could be due to patient characteristics, rather than assisted reproduction itself, although both surveillance bias and the effect of treatment are also possibilities. Ongoing monitoring of this population is essential.

Increased rounds of gonadotropin stimulation have side effects on mouse fallopian tubes and oocytes

In this study, it was evaluated if increased rounds of gonadotropin stimulation could affect in mice: (i) expression levels of proteins regulating cell cycle and DNA repair in fallopian tubes and (ii) meiotic spindle morphology of ovulated oocytes. To this end, adult female mice were subjected or not (Control) to 6 or 8 rounds of gonadotropin stimulation. Ovulated oocytes were incubated with anti A/B tubulin to evaluate spindle morphology. Fallopian tubes were analyzed to detect Cyclin D1, phospho-p53/p53, phospho-AKT/AKT, phospho-GSK3B/GSK3B, SOX2, OCT3/4, phospho-B-catenin/B-catenin, phospho-CHK1 and phospho-H2A.X protein levels. After 6 rounds, Cyclin D1, p53 and phospho-p53 contents were higher than Control. After 8 rounds, the contents of phosphorylated AKT, GSK3B and p53 as well as of total p53, Cyclin D1 and OCT3/4 significantly increased in comparison with Control. Conversely, SOX2 and B-catenin were similarly expressed among all experimental groups. The finding that phospho-CHK1 and phospho-H2A.X protein levels were undetectable supported the absence of extensive DNA damage. Oocytes number and percentage of normal meiotic spindles drastically decreased from 6 rounds onward. Altogether, our results demonstrated that 6 and 8 cycles of gonadotropin stimulation reduce mouse reproductive performances by inducing over-expression and over-activation of proteins controlling cell cycle progression in fallopian tubes and by impairing oocyte spindle.

Cancer Risk in Women Treated with Fertility Drugs According to Parity Status-A Registry-based Cohort Study

Background: Long-term safety of assisted reproductive techniques (ART) is of interest as their use is increasing. Cancer risk is known to be affected by parity. This study examined the risk of cancer after fertility treatment, stratified by women's parity.Methods: Data were obtained from all women (n = 1,353,724) born in Norway between 1960 and 1996. Drug exposure data (2004-2014) were obtained from the Norwegian Prescription Database (drugs used in ART and clomiphene citrate). The Medical Birth Registry of Norway provided parity status. HRs were calculated for all site cancer, breast, cervical, endometrial, ovarian, colorectal, central nervous system, thyroid cancer, and malignant melanoma.Results: In 12,354,392 person-years of follow-up, 20,128 women were diagnosed with cancer. All-site cancer risk was 1.14 [95% confidence interval (95% CI), 1.03-1.26] and 1.10 (95% CI, 0.98-1.23) after clomiphene citrate and ART exposure, respectively. For ovarian cancer, a stronger association was observed for both exposures in nulliparous (HR, 2.49; 95% CI, 1.30-4.78; and HR, 1.62; 95% CI, 0.78-3.35) versus parous women (HR, 1.37; 95% CI, 0.64-2.96; and HR, 0.87; 95% CI, 0.33-2.27). Elevated risk of endometrial cancers was observed for clomiphene citrate exposure in nulliparous women (HR, 4.49; 95% CI, 2.66-7.60 vs. HR, 1.52; 95% CI, 0.67-3.42). Risk was elevated for breast cancer in parous women exposed to clomiphene citrate (HR, 1.26; 95% CI, 1.03-1.54) for thyroid cancer and among nulliparous women after ART treatment (HR, 2.19; 95% CI, 1.08-4.44).Conclusions: Clomiphene citrate appears associated with increased risk of ovarian and endometrial cancer. Elevations in risks of breast and thyroid cancer were less consistent across type of drug exposure and parity.Impact: Continued monitoring of fertility treatments is warranted. Cancer Epidemiol Biomarkers Prev; 26(6); 953-62. ©2017 AACR.

Epidemiology of epithelial ovarian cancer

Globally, ovarian cancer is the seventh most common cancer in women and the eighth most common cause of cancer death, with five-year survival rates below 45%. Although age-standardised rates are stable or falling in most high-income countries, they are rising in many low and middle income countries. Furthermore, with increasing life-expectancy, the number of cases diagnosed each year is increasing. To control ovarian cancer we need to understand the causes. This will allow better prediction of those at greatest risk for whom screening might be appropriate, while identification of potentially modifable causes provides an opportunity for intervention to reduce rates. In this paper we will summarise the current state of knowledge regarding the known and possible causes of epithelial ovarian cancer and discuss some of the main theories of ovarian carcinogenesis. We will also briefly review the relationship between lifestyle and survival after a diagnosis of ovarian cancer.

Fertility drugs and cancer: a guideline

Methodological limitations in studying the association between the use of fertility drugs and cancer include the inherent increased risk of cancer in women who never conceive, the low incidence of most of these cancers, and that the age of diagnosis of cancer typically is many years after fertility drug use. Based on available data, there does not appear to be a meaningful increased risk of invasive ovarian cancer, breast cancer, or endometrial cancer following the use of fertility drugs. Several studies have shown a small increased risk of borderline ovarian tumors; however, there is insufficient consistent evidence that a particular fertility drug increases the risk of borderline ovarian tumors, and any absolute risk is small. Given the available literature, patients should be counseled that infertile women may be at an increased risk of invasive ovarian, endometrial, and breast cancer; however, use of fertility drugs does not appear to increase this risk.

Population attributable risks of modifiable reproductive factors for breast and ovarian cancers in Korea

Background

Breast and ovarian cancers are predominant female cancers with increasing prevalence. The purpose of this study was to estimate the population attributable risks (PARs) of breast and ovarian cancer occurrence based on the relative risks (RRs) of modifiable reproductive factors and population-specific exposure prevalence.

Methods

The PAR was calculated by using the 1990 standardized prevalence rates, the 2010 national cancer incidence with a 20 year lag period, the meta-analyzed RRs from studies conducted in the Korean population for breast cancer, and the meta-analyzed RRs from a Korean epithelial ovarian cancer study and a prior meta-analysis, and ovarian cancer cohort results up to 2012. For oral contraceptive and hormone replacement therapy use, we did not consider lag period.

Results

The summary PARs for modifiable reproductive factors were 16.7 % (95 % CI 15.8–17.6) for breast cancer (2404 cases) and 81.9 % (95 % CI 55.0–100.0) for ovarian cancer (1579 cases). The modifiable reproductive factors included pregnancy/age at first birth (8.0 %), total period of breastfeeding (3.1 %), oral contraceptive use (5.3 %), and hormone replacement therapy use (0.3 %) for breast cancer and included breastfeeding experience (2.9 %), pregnancy (1.2 %), tubal ligation (24.5 %), and oral contraceptive use (53.3 %) for ovarian cancer.

Conclusions

Despite inherent uncertainties in the risk factors for breast and ovarian cancers, we suggest that appropriate long-term control of modifiable reproductive factors could reduce breast and ovarian cancer incidences and their related burdens by 16.7 % and 81.9 %, respectively.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-2040-0) contains supplementary material, which is available to authorized users.

Environmental (nongenetic) factors in gynecological cancers: update and future perspectives

Globally, gynecological cancers comprise three of the seven most common female cancers and are responsible for more than 1,000,000 new cases and 500,000 deaths annually. This review summarizes current knowledge regarding the role of environmental factors in gynecological cancer etiology and survival, focusing on those that are potentially amenable to intervention. Strong associations with use of exogenous hormones are countered by opposing risks of breast cancer, thus current hormonal preparations are not an option for prevention. Weight control would reduce risk of endometrial cancer but this and other lifestyle modifications are unlikely to have a major effect on gynecological cancer mortality rates. There is little information regarding the potential for lifestyle changes to improve outcomes for women with gynecological cancer.

Mental disorders in childhood and young adulthood among children born to women with fertility problems

STUDY QUESTION

Is the risk of hospital admission or outpatient contact for mental disorders increased in children born to women with fertility problems compared with children born to women without fertility problems?

SUMMARY ANSWER

We found an increased risk of hospital admission or outpatient contact for mental disorders in children born to women with fertility problems.

WHAT IS KNOWN ALREADY

Few studies have investigated the risk of mental disorders in children born after fertility treatment and although some studies have pointed to an increased risk, others found no association. The inconsistent results may be due to methodological constraints in many previous studies, including small sample size and short follow-up, resulting in imprecise risk estimates and lack of information on risk patterns of mental disorders in adulthood.

STUDY DESIGN, SIZE, DURATION

This nationwide retrospective register-based cohort study included all 2 412 721 children born in Denmark between 1969 and 2006. All children were followed from date of birth until date of hospital contact for a mental disorder, date of emigration, date of death or 31 December 2009, whichever occurred first.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Information concerning maternal fertility status for all children in the cohort was obtained by linkage to the Danish Infertility Cohort, which contains data on nearly all women with fertility problems in Denmark since 1963. A total of 124 269 (5%) children were born to women with fertility problems and 2 288 452 (95%) to women without fertility problems. To identify children hospitalized for a mental disorder, the cohort was linked to the Danish Psychiatric Central Research Registry. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between maternal fertility status and the risk of hospital admission or outpatient contact for various groups of mental disorders, including any mental disorder and all 11 main discharge diagnostic groups, classified according to the International Classification of Diseases, version 10.

MAIN RESULTS AND THE ROLE OF CHANCE

During a mean follow-up period of 21 years (range, 0-40 years), 168 686 (7%) children were admitted to hospital or had an outpatient contact for a mental disorder. Children born to women with fertility problems had a significantly higher risk of any mental disorder (HR 1.23; 95% CI 1.20-1.26) and for most of the 11 main discharge groups, including schizophrenia (HR 1.16; 95% CI 1.07-1.27), mood (affective) disorders (HR 1.21; 95% CI 1.15-1.28) and disorders of psychological development (HR 1.15; 95% CI 1.09-1.21) as well as the subgroup of attention-deficit/hyperactivity disorders (HR 1.36; 95% CI 1.29-1.45) compared with children born to women without fertility problems. The risk estimates did not change markedly when analyses were performed separately for mental disorders diagnosed during childhood (0-19 years) and in young adulthood (20-40 years).

LIMITATIONS, REASON FOR CAUTION

The true risk of mental disorders may be somewhat underestimated, as only severe disorders requiring hospital admission or outpatient contact were considered as events. Furthermore, we could not determine whether the increased risks observed were due to factors related to the underlying infertility or to fertility treatment procedures.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first report on mental disorders in adulthood among children born to women with fertility problems. Furthermore, we have assessed the risk of several severe mental disorders not previously studied (e.g. neurotic, stress-related and somatoform disorders and disorders of adult personality and behaviour). These important findings should be investigated further in large epidemiological studies designed to differentiate between factors related to fertility treatment and to the underlying infertility.

STUDY FUNDING/COMPETING INTERESTS

The study was supported by internal funding from the Unit of Virus, Lifestyle and Genes at the Danish Cancer Society Research Center. All authors report no conflicts of interest.

Does ovarian stimulation for IVF increase gynaecological cancer risk? A systematic review and meta-analysis

The aim of this study was to evaluate whether ovarian stimulation for IVF increases the risk of gynaecological cancer, including ovarian, endometrial, cervical and breast cancers, as an independent risk factor. A systematic review and meta-analysis was conducted. Clinical trials that examined the association between ovarian stimulation for IVF and gynaecologic cancers were included. The outcomes of interest were incidence rate of gynaecologic cancers. Twelve cohort studies with 178,396 women exposed to IVF were included; 10 studies were used to analyse ovarian (167,640 women) and breast (151,702 women) cancers, and six studies were identified in the analysis of endometrial (116,672 women) and cervical cancer (114,799 women). Among these studies, 175 ovarian, 48 endometrial, 502 cervical and 866 cases of breast cancer were reported. The meta-analysis found no significant association between ovarian stimulation for IVF and increased ovarian, endometrial, cervical and breast cancer risk (odds ratio [OR] 1.06, 95% confidence interval [CI] 0.85 to 1.32; OR 0.97, 95% CI 0.58 to 1.63; OR 0.43, 95% CI 0.30 to 0.60; OR 0.69, 95% CI 0.63 to 0.76, respectively). Ovarian stimulation for IVF, therefore, does not increase the gynaecologic cancer risk, whether hormone-dependent endometrial and breast cancer or non-hormone-dependent ovarian and cervical cancer.

Use of fertility drugs and risk of ovarian cancer

PURPOSE OF REVIEW

The purpose of this review is to highlight recent research and insights into the relationship between fertility drug use and ovarian cancer risk.

RECENT FINDINGS

Results from two large case-control studies provided further evidence that fertility drug use does not significantly contribute to risk of ovarian cancer among the majority of women when adjusting for known confounding factors. However, questions regarding the effect on certain subgroups, including long-term fertility drug users, women who remain nulligravid after fertility treatment, women with BRCA1 or BRCA2 mutations and borderline ovarian tumours, still remain. In addition, it may currently just be too early to determine whether there is an association between fertility drug use and ovarian cancer risk given that many of the exposed women are only now beginning to reach the ovarian cancer age range.

SUMMARY

Whether use of fertility drugs increases the risk of ovarian cancer is an important question that requires further investigation, in particular given the large number of women utilizing fertility treatments. Fortunately, results from recent studies have been mainly reassuring. Large well designed studies with sufficient follow-up time are needed to further evaluate the effects of fertility treatments within subgroups defined by patient and tumour characteristics.

Metformin-clinical pharmacology in PCOs

Oligo-anovulation, hyperandrogenism and insulin resistance characterizes polycystic ovary syndrome (PCOs). Metformin is the oldest insulin sensitizer used in the management of type 2 diabetes mellitus. In PCOs, metformin decreases the serum lipids, androgen and insulin; induces ovulation and regular menstrual cycle; increases the pregnancy rate.

Risk for borderline ovarian tumours after exposure to fertility drugs: results of a population-based cohort study

STUDY QUESTION

Do fertility drugs increase the risk for borderline ovarian tumours, overall and according to histological subtype?

SUMMARY ANSWER

The use of any fertility drug did not increase the overall risk for borderline ovarian tumours, but an increased risk for serous borderline ovarian tumours was observed after the use of progesterone.

WHAT IS KNOWN ALREADY

Many epidemiological studies have addressed the connection between fertility drugs use and risk for ovarian cancer; most have found no strong association. Fewer studies have assessed the association between use of fertility drugs and risk for borderline ovarian tumours, and the results are inconsistent.

STUDY DESIGN, SIZE, DURATION

A retrospective case-cohort study was designed with data from a cohort of 96 545 Danish women with fertility problems referred to all Danish fertility clinics in the period 1963-2006. All women were followed for first occurrence of a borderline ovarian tumour from the initial date of infertility evaluation until a date of migration, date of death or 31 December 2006, whichever occurred first. The median length of follow-up was 11.3 years.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Included in the analyses were 142 women with borderline ovarian tumours (cases) and 1328 randomly selected sub-cohort members identified in the cohort during the follow-up through 2006. Cases were identified by linkage to the Danish Cancer Register and the Danish Register of Pathology by use of personal identification numbers. To obtain information on use of fertility drugs, hospital files and medical records of infertility-associated visits to all Danish fertility clinics were collected and supplemented with information from the Danish IVF register. We used case-cohort techniques to calculate rate ratios (RRs) and corresponding 95% confidence intervals (CIs) for borderline ovarian tumours, overall and according to histological subtype, associated with the use of any fertility drug or five specific groups of fertility drugs: clomiphene citrate, gonadotrophins (human menopausal gonadotrophins and follicle-stimulating hormone), gonadotrophin-releasing hormone analogues, human chorionic gonadotrophins and progesterone.

MAIN RESULTS AND THE ROLE OF CHANCE

Analyses within the cohort showed that the overall risk for borderline ovarian tumours was not associated with the use of any fertility drug (RR 1.00; 95% CI 0.67-1.51) or of gonadotrophins (RR 1.32; 95% CI 0.81-2.14), clomiphene citrate (RR 0.96; 95% CI 0.64-1.44), human chorionic gonadotrophins (RR 0.91; 95% CI 0.61-1.36) or gonadotrophin-releasing hormone analogues (RR 1.10; 95% CI 0.66-1.81). Furthermore, no associations were observed between the risk for borderline ovarian tumours and these groups of fertility drugs according to the number of cycles of use, length of follow-up or parity. In contrast, use of progesterone increased the risk for borderline ovarian tumours, particularly serous tumours, for which statistically significantly increased risks were observed with any use of progesterone (RR 1.82; 95% CI 1.03-3.24), among women treated with ≥4 cycles of progesterone (RR 2.63; 95% CI 1.04-6.64) and for all women followed up for ≥4 years after their first treatment with progesterone.

LIMITATIONS, REASONS FOR CAUTION

Although we tried to minimize the effects of the underlying infertility, the severity of infertility might have affected our risk estimates, as women with more severe fertility problems may receive more treatment. The results from the subgroup analyses, e.g. the findings of an elevated risk for borderline ovarian tumours associated with increased time since first use of progesterone and with increased number of treatment cycles, should be interpreted with caution as these analyses are based on a limited number of women with borderline ovarian tumours.

WIDER IMPLICATIONS OF THE FINDINGS

Although this study, which is the largest to date, provides reassuring evidence that there is no strong link between the use of fertility drugs and risk for borderline ovarian tumours, the novel observation of an increased risk for serous tumours after use of progesterone should be investigated in large epidemiological studies. The results of the present study provide valuable knowledge for clinicians and other health care personnel involved in the diagnosis and treatment of fertility problems.

STUDY FUNDING/COMPETING INTERESTS

No conflict of interest was reported. S.M.B. was supported by a research scholarship from the Danish Cancer Society.

Protective Effect of Progesterone during Pregnancy against Ovarian Cancer

There have been several epidemiologic studies supporting the protective role of pregnancy, although the mechanism is not clear. High level of progesterone, which is crucial in maintaining pregnancy, has been supposed to be one of the causative factors. Progesterone is produced at the corpus luteum in the early pregnancy and the placenta in the late pregnancy period. In several experimental studies, progesterone was reported to induce apoptosis of ovarian cancer cells through intrinsic and extrinsic pathways. In addition, progesterone has been shown to exert its anticancer effect through genomic and non-genomic action. The objective of this review is to discuss the protective mechanism of pregnancy against ovarian cancer focusing on the steroid hormone, progesterone.

Metformin use in women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is an endocrinopathy characterised by increased resistance to insulin. Metformin is one of the longest established oral insulin sensitising agents. For decades its use was restricted to management of type 2 diabetes. However, in the past two decades, its properties as an insulin sensitising agent have been explored in relation to its applicability for women with PCOS. Metformin is an effective ovulation induction agent for non-obese women with PCOS and offers some advantages over other first line treatments for anovulatory infertility such as clomiphene. For clomiphene-resistant women, metformin alone or in combination with clomiphene is an effective next step. Women with PCOS undergoing in vitro fertilisation should be offered metformin to reduce their risk of ovarian hyperstimulation syndrome. Limited evidence suggests that metformin may be a suitable alternative to the oral contraceptive pill (OCP) for treating hyperandrogenic symptoms of PCOS including hirsutism and acne. More research is required to define whether metformin has a role in improving long term health outcomes for women with PCOS, including the prevention of diabetes, cardiovascular disease and endometrial cancer.

Maternal use of fertility drugs and risk of cancer in children--a nationwide population-based cohort study in Denmark

Large population-based studies are needed to examine the effect of maternal use of fertility drugs on the risk of cancer in children, while taking into account the effect of the underlying infertility. A cohort of 123,322 children born in Denmark between 1964 and 2006 to 68,255 women who had been evaluated for infertility was established. We used a case-cohort design and calculated hazard ratios (HRs) for cancer in childhood (0-19 years) and in young adulthood (20-29 years) associated with maternal use of six groups of fertility drugs (clomiphene, gonadotropins [i.e., human menopausal gonadotropins and follicle-stimulating hormone], gonadotropin-releasing hormone analogs, human chorionic gonadotropins, progesterone and other fertility drugs). We found no statistically significant association between maternal use of fertility drugs and risk for overall cancer in childhood or young adulthood. However, with regard to specific cancers in childhood, our results showed that maternal use of progesterone before childbirth markedly increased the risks of their offspring for acute lymphocytic leukemia (any use: HR, 4.95; 95% CI, 1.69-14.54; ≥ three cycles of use: HR, 9.96; 95% CI, 2.63-37.77) and for sympathetic nervous system tumors (any use: HR, 5.79; 95% CI, 1.23-27.24; ≥ three cycles of use: HR, 8.51; 95% CI, 1.72-42.19). These findings show that maternal use of progesterone may increase the risk for specific cancers in the offspring. Additional large epidemiological studies are urgently needed to confirm our finding.

Fertility drugs, reproductive strategies and ovarian cancer risk

Several adverse effects have been related to infertility treatments, such as cancer development. In particular, the relationship between infertility, reproductive strategies, and risk of gynecological cancers has aroused much interest in recent years. The evaluation of cancer risk among women treated for infertility is very complex, mainly because of many factors that can contribute to occurrence of cancer in these patients (including parity status). This article addresses the possible association between the use of fertility treatments and the risk of ovarian cancer, through a scrupulous search of the literature published thus far in this field. Our principal objective was to give more conclusive answers on the question whether the use of fertility drug significantly increases ovarian cancer risk. Our analysis focused on the different types of drugs and different treatment schedules used. This study provides additional insights regarding the long-term relationships between fertility drugs and risk of ovarian cancer.

Repeated ovarian stimulation does not affect the expression level of proteins involved in cell cycle control in mouse ovaries and fallopian tubes

PURPOSE

To understand if repeated cycles (2-4 rounds) of gonadotropin stimulation could affect intracellular localization/content of proteins controlling cell cycle progression in mouse fallopian tubes (FT) and ovaries.

METHODS

FT and ovaries of estrous mice (control) and of stimulated mice were analyzed to detect Oct-3/4, Sox-2, p53, β-catenin, pAKT and cyclin D1 localization/content. Spindles and chromosome alignment were analyzed in ovulated oocytes.

RESULTS

After round 4, FT and ovaries of control and stimulated groups showed no differences in Oct-3/4, Sox-2 and β-catenin localization nor in Oct-3/4, Sox-2, p53, β-catenin and pAKT contents. Cyclin D1 level increased significantly in FT of treated mice. Oocytes number decreased meanwhile frequency of abnormal meiotic spindles increased with treatments.

CONCLUSIONS

Repetitive stimulations affected oocyte spindle morphology but did not induce changes in a set of proteins involved in cell cycle progression, usually altered in ovarian cancer. The significant increase of cyclin D1 in the FT requires further investigation.

Ovarian cancer: risk factors, treatment and management

Ovarian cancer is the fifth most common cancer affecting women in the UK today, with associated statistics illustrating a steadily increasing rate, particularly in women aged 65 and over (Cancer Research UK, 2013). There are no recognised preventative measures and no effective screening tool. Although evidence suggests that the majority of women experience a variety of non-specific symptoms in the year before diagnosis, the disease it is not commonly recognised until an advanced stage, leading to increased mortality and morbidity. This highlights the need to raise awareness among health professionals and women as a whole, as early recognition undoubtedly improves ovarian cancer survival. Best clinical practice in the UK for the recognition and initial management of ovarian cancer is provided by the National Institute for Health and Care Excellence (NICE). Clinical guideline CG 122 (NICE, 2011) and quality standard QS 18 (NICE, 2012) use relevant clinical evidence to define high-quality care standards for ovarian cancer management. Accurate staging of ovarian cancer is essential to the provision of individualised care and management. However, there is currently no single test that provides a reliable indicator of ovarian malignancy. At present, risk-of-malignancy scores are calculated by serum cancer antigen 125 (CA 125) levels, ultrasound score and menopausal status. These are widely used to identify women who are at high risk and require referral to a specialised gynaecological oncology service. Women diagnosed with ovarian cancer require information and support. The clinical nurse specialist acts as a key worker, providing communication, support and holistic care throughout a woman's cancer journey. The value of this role cannot be underestimated. Surgery followed by platinum-based chemotherapy is the usual standard treatment pathway, although individualised assessment and management may deviate from it. Early disease may be successfully treated with surgery alone; advanced disease may require complex management and treatment. New treatments such as bevacizumab show promise of improving ovarian cancer outcomes.

Ovulation-inducing drugs and ovarian cancer risk: results from an extended follow-up of a large United States infertility cohort

OBJECTIVE

To examine the relationship of ovulation-inducing drugs and ovarian cancer.

DESIGN

Retrospective cohort study, with additional follow-up since initial report.

SETTING

Five large reproductive endocrinology practices.

PATIENT(S)

In a retrospective cohort of 9,825 women evaluated for infertility at five clinical sites in the United States between 1965 and 1988 with follow-up through 2010, we examined the relationship of ovulation-inducing drugs and ovarian cancer (n = 85).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Hazard rate ratios (RR) and 95% confidence intervals (CI) for ovarian cancer.

RESULT(S)

Among women evaluated for infertility, there was no association of ovarian cancer risk with ever use of clomiphene citrate (CC) (adjusted RR 1.34, 95% CI 0.86-2.07) or gonadotropins (RR 1.00, 95% CI 0.48-2.08) and no evidence that any of several more detailed subgroups of usage were related to an increased risk with one exception: women who used CC and remained nulligravid did demonstrate much higher risks than those who successfully conceived compared with nonusers (respectively, RR 3.63, 95% CI 1.36-9.72 vs. RR 0.88, 95% CI 0.47-1.63).

CONCLUSION(S)

Our overall results were reassuring and consistent with other studies. A reason for an association between CC use and ovarian cancer among persistently nulligravid women remains to be determined. Given the large and increasing number of women treated with ovulation-inducing drugs, the increased risk of ovarian cancer among the subset of women who remained nulligravid should be further monitored.

Increased risk for ovarian cancer and borderline ovarian tumours in subfertile women with endometriosis

STUDY QUESTION

Is ovarian or extra-ovarian endometriosis associated with an increased risk of ovarian cancer and borderline ovarian tumours (BOT)?

SUMMARY ANSWER

We found a 3- to 8-fold increased risk of ovarian tumours associated with endometriosis: the magnitude of the risk increase depended on the definition of endometriosis.

WHAT IS KNOWN ALREADY

There is increasing evidence of an association between endometriosis and increased risk of ovarian cancer. However, most reports were based on self-reported diagnosis of endometriosis.

STUDY DESIGN, SIZE, DURATION

We conducted a nationwide historic cohort study among women with subfertility problems between 1980 and 1995. For this analysis we selected all cohort members with endometriosis, and a comparison group of subfertile women (male factor or idiopathic) without endometriosis (total cohort of 8904 women). Median follow-up time was 15.2 for the entire study population.

PARTICIPANTS/MATERIALS, SETTING, METHODS

For this analysis we selected all cohort members with (n = 3657) and without (n = 5247) evidence of endometriosis. Seventy-eight per cent of diagnoses of endometriosis were confirmed by pathology report, and 22% was self-reported endometriosis (positive predictive value of 73%). We linked the cohort with the Dutch Pathology Database and the Netherlands Cancer Registry to assess the occurrence of ovarian cancer and BOT between January 1989 and June 2007.

MAIN RESULTS AND THE ROLE OF CHANCE

We observed a substantially increased risk of all ovarian malignancies combined in women with endometriosis when we based the definition of endometriosis on self-report, medical records information at subfertility treatment and/or the nationwide pathology database (hazard ratio (HR) 8.2; 95% confidence interval (CI) 3.1-21.6). The HR associated with endometriosis was 12.4 (95% CI 2.8-54.2) for ovarian cancer and 5.5 (95% CI 1.5-20.2) for BOT. When we excluded information from the pathology database, HRs were 3.0 (95% CI 1.5-6.1) for all ovarian tumours, 4.3 (95% CI 1.6-11.2) for ovarian cancer and 1.9 (95% CI 0.6-5.8) for BOT. Both ovarian and extra-ovarian endometriosis carried a significantly increased risk for ovarian cancer and BOT.

LIMITATIONS, REASONS FOR CAUTION

We did not have information on oral contraceptive use and parity for 23.4 and 3.4%, of women in the analytic cohort, respectively. Furthermore, a limitation of our study, and also of other studies, is that the date of diagnosis of endometriosis is usually made long after the onset of the disease. Also, the number of cases in the cohort is small (n = 34), resulting in wide CIs.

WIDER IMPLICATIONS OF THE FINDINGS

The fact that endometriosis was assessed before diagnosis of ovarian malignancy and the high degree of medical confirmation in our study likely contribute to the validity of our estimate of a 3- to 8-fold increased risk of ovarian tumours associated with endometriosis. The risk of ovarian malignancies associated with endometriosis was much higher in analyses including information on endometriosis from the nationwide pathology database, implying that risk estimates from studies using self-reported information on endometriosis may be too low due to non-differential misclassification bias.

STUDY FUNDING/COMPETING INTEREST(S)

None.

TRIAL REGISTRATION NUMBER

None.

Risk of ovarian cancer in women treated with ovarian stimulating drugs for infertility

BACKGROUND

The use of assisted reproductive techniques is increasing, but the possible link between fertility drugs and ovarian cancer remains controversial.

OBJECTIVES

To evaluate the risk of ovarian cancer in women treated with ovulation stimulating drugs for subfertility.

SEARCH METHODS

We searched for published and unpublished observational studies from 1990 to February 2013. The following databases were used: the Cochrane Gynaecological Cancer Collaborative Review Group's Trial Register, Cochrane Central Register of Controlled Trials (CENTRAL) 2013, Issue 1, MEDLINE (to February week 4 2013), EMBASE (to 2013 week 09) and databases of conference abstracts. We also scanned reference lists of retrieved articles. The search was not restricted by language of publication.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) and non-randomised studies, and case series including more than 30 participants, reporting on women with exposure to ovarian stimulating drugs for treatment of subfertility and histologically confirmed borderline or invasive ovarian cancer.

DATA COLLECTION AND ANALYSIS

At least two review authors independently conducted eligibility and 'Risk of bias' assessment, and extracted data. We grouped studies based on the fertility drug used for two outcomes: borderline ovarian tumours and invasive ovarian cancer. We expressed findings as adjusted odds ratio (OR), risk ratio (RR), hazard ratio (HR) or crude OR if adjusted values were not reported and standardised incidence ratio (SIR) where reported. We conducted no meta-analyses due to expected methodological and clinical heterogeneity.

MAIN RESULTS

We included 11 case-control studies and 14 cohort studies, which included a total of 182,972 women.Seven cohort studies showed no evidence of an increased risk of invasive ovarian cancer in subfertile women treated with any drug compared with untreated subfertile women. Seven case-control studies showed no evidence of an increased risk, compared with control women of a similar age. Two cohort studies reported an increased incidence of invasive ovarian cancer in subfertile women treated with any fertility drug compared with the general population. One of these reported a SIR of 5.0 (95% confidence interval (CI) 1.0 to 15), based on three cancer cases, and a decreased risk when cancer cases diagnosed within one year of treatment were excluded from the analysis(SIR 1.67, 95% CI 0.02 to 9.27). The other cohort study reported an OR of 2.09 (95% CI 1.39 to 3.12), based on 26 cases.For borderline ovarian tumours, exposure to any fertility drug was associated with a two to three-fold increased risk in two case-control studies. One case-control study reported an OR of 28 (95% CI 1.5 to 516), which was based on only four cases. In one cohort study, there was more than a two-fold increase in the incidence of borderline tumours compared with the general population (SIR 2.6, 95% CI 1.4 to 4.6) and in another the risk of a borderline ovarian tumour was HR 4.23 (95% CI 1.25 to 14.33) for subfertile women treated with in vitro fertilisation (IVF) compared with a non-IVF treated group with more than one year of follow-up.There was no evidence of an increased risk in women exposed to clomiphene alone or clomiphene plus gonadotrophin, compared with unexposed women. One case-control study reported an increased risk in users of human menopausal gonadotrophin (HMG)(OR 9.4, 95% CI 1.7 to 52). However, this estimate is based on only six cases with a history of HMG use.

AUTHORS' CONCLUSIONS

We found no convincing evidence of an increase in the risk of invasive ovarian tumours with fertility drug treatment. There may be an increased risk of borderline ovarian tumours in subfertile women treated with IVF. Studies showing an increase in the risk of ovarian cancer had a high overall risk of bias, due to retrospective study design, lack of accounting for potential confounding and estimates based on a small number of cases. More studies at low risk of bias are needed.

Fertility drug use and the risk of ovarian tumors in infertile women: a case-control study

OBJECTIVE

To assess the influence of infertility and fertility drugs on risk of ovarian tumors.

DESIGN

Case-control study (Mayo Clinic Ovarian Cancer Study).

SETTING

Ongoing academic study of ovarian cancer.

PATIENT(S)

A total of 1,900 women (1,028 with ovarian tumors and 872 controls, frequency matched on age and region of residence) who had provided complete information in a self-report questionnaire about history of infertility and fertility drug use.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Effect of infertility history, use of fertility drugs and oral contraception, and gravidity on the risk of ovarian tumor development, after controlling for potential confounders.

RESULT(S)

Among women who had a history of infertility, use of fertility drugs was reported by 44 (24%) of 182 controls and 38 (17%) of 226 cases. Infertile women who used fertility drugs were not at increased risk of developing ovarian tumors compared with infertile women who did not use fertility drugs; the adjusted odds ratio was 0.64 (95% CI, 0.37, 1.11). The findings were similar when stratified by gravidity and when analyzed separately for borderline versus invasive tumors.

CONCLUSION(S)

We found no statistically significant association between fertility drug use and risk of ovarian tumors. Further larger, prospective studies are needed to confirm this observation.

Increased risk for cancer among offspring of women with fertility problems

Some studies have indicated that children born after fertility treatment have a potential risk for cancer, but the results are inconsistent. Furthermore, any negative effects of fertility treatment might be due to the underlying infertility rather than to the procedure itself. In the largest cohort study to date with information on fertility, we examined whether the offspring of women with fertility problems had a higher risk for cancer than offspring of women without fertility problems. The study cohort consisted of 2,830,054 offspring born in Denmark between 1964 and 2006. Of these, 125,844 were offspring of women evaluated for infertility. Cox regression models were used to estimate the possible effect of being the offspring of a woman evaluated for infertility on the risk for cancer. Analyses were performed separately for cancer during childhood (0-19 years) and cancer in young adulthood (>20 years). We found that offspring born to women with fertility problems had higher overall risks for cancer in childhood (hazard ratio (HR), 1.18; 95% confidence interval (CI), 1.05-1.32) and in young adulthood (HR, 1.22; 95% CI, 1.04-1.43) than offspring of women without fertility problems. Offspring of women with fertility problems had significantly increased risks for leukemia in childhood (HR, 1.30; 95% CI, 1.06-1.60) and for cancer of the endocrine glands in young adulthood (HR, 2.67; 95% CI, 1.35-5.29). These findings suggest that offspring born to mothers with fertility problems are at increased risk for cancer in both childhood and young adulthood. If real, our findings of an ∼18% overall increase in risk for cancer in childhood and an ∼22% overall increase in risk for cancer in young adulthood would mean about four additional cases of childhood cancer and about nine additional cases of cancer in young adults per 100,000 exposed offspring.

In vitro fertilization and risk of breast and gynecologic cancers: a retrospective cohort study within the Israeli Maccabi Healthcare Services

OBJECTIVE

To assess long-term cancer risks associated with in vitro fertilization (IVF).

DESIGN

Record-linkage study.

SETTING

Health maintenance organization in Israel.

PATIENT(S)

A total of 87,403 women evaluated and/or treated for infertility on or after September 25, 1994, who were followed for cancer development through June 22, 2011: 522 breast, 41 endometrial, 45 ovarian, 311 in situ cervical, and 32 invasive cervical cancers were identified.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Hazard ratios (HRs) for specific cancers.

RESULT(S)

We found no significant relationships of IVF exposures to the risks of breast, endometrial, or ovarian cancers. However, compared with women with no fertility treatment, the HR for ovarian cancer associated with IVF was 1.58 (95% confidence interval [CI] 0.75-3.29), with higher risk among those receiving four or more cycles (HR 1.78, 95% CI 0.76-4.13). There was also a nonsignificantly elevated risk for endometrial cancer among women who received 1-3 IVF cycles (HR 1.94, 95% CI 0.73-5.12), but additional cycles were associated with less risk. In contrast, the risk of in situ cervical cancer was significantly reduced and invasive cervical cancer nonsignificantly reduced among women receiving IVF as well as other fertility treatments.

CONCLUSION(S)

Our results regarding long-term effects were largely reassuring, but women receiving IVF should continue to be monitored given that the procedures involve potent ovulation stimulators and repeated ovarian punctures.

Fertility drug use and risk of ovarian tumors: a debated clinical challenge

Infertility itself increases the incidence of ovarian carcinoma, while the potential additional risk associated with the use of fertility drugs is still debated. In 1992, the cumulative analysis of 12 US case-control studies revealed that women who received ovulation-inducing drugs had approximately three-fold higher incidence of invasive ovarian carcinoma. Other investigations reported a lower increase of the risk of invasive carcinoma or borderline tumor of the ovary in women treated with these agents. Conversely, several other case-control or cohort studies failed to detect a significant correlation between fertility drug use and ovarian tumor risk in either parous or nulliparous women compared with untreated infertile women. Moreover neither the number of treatment cycles nor the type of drug used was associated with an increased risk in most studies. Incessant ovulation and excessive gonadotropin secretion have been long considered to play a major role in the development of ovarian carcinoma, and therefore fertility drugs, which raise the serum levels of gonadotropins and increase the chances of multiple ovulations, have been retained as a risk factor for this malignancy, However, the large majority of literature data as well as the new hypotheses on ovarian carcinogenesis appear to exclude a relevant impact of fertility drug use on the risk of ovarian tumors, and especially of high-grade invasive epithelial ovarian cancers.

Are infertility treatments a potential risk factor for cancer development? Perspective of 30 years of follow-up

The aim of the present study was to evaluate the possible risk for cancer development in infertile women with over 30 years of follow-up. Cancer development was assessed through linkage with the National Cancer Registry updated to 31 December 2005 in a cohort of 2431 women who were treated for infertility at the Sheba Medical Center in Israel during the period 1964-1974 and contributed more than 84,000 women years of follow-up. Standardized incidence ratios (SIR) were calculated between the observed cancer cases and the expected cancer rates in the general population. The mean age at the end of follow-up was 62.7 years. Eighteen cases of ovarian cancer were observed as compared to 18.1 expected (SIR = 1.0; 95% CI = 0.59-1.57). For breast cancer, 153 cases were observed as compared to 131.9 expected (SIR = 1.16; 95% CI = 0.98-1.36), and for endometrial cancer, 30 cases were observed as compared to 17.8 expected cases (SIR = 1.69; 95% CI = 1.14-2.41). No excess risk associated with exposure to gonadotropins was observed. Infertility was found to be associated with significant increased risk for endometrial cancer and borderline increased risk for breast cancer. Ovarian cancer risk was not found to be elevated. No significant excess risk was associated with treatment with ovulation induction.

Ovarian cancer: etiology, risk factors, and epidemiology

Little is known regarding the early aspects of ovarian carcinogenesis. As a consequence, the identification of women at risk for the disease is based primarily on clinical grounds, with family history being the most important risk factor. In this review, we will discuss the various hypotheses regarding ovarian etiology and pathogenesis. In addition, we will discuss the epidemiology of ovarian cancer, including hereditary, reproductive, hormonal, inflammatory, dietary, surgical, and geographic factors that influence ovarian cancer risk.

Use of fertility drugs and risk of ovarian cancer: results from a U.S.-based case-control study

BACKGROUND

Previous studies examining associations between use of fertility drugs and ovarian cancer risk have provided conflicting results. We used data from a large case-control study to determine whether fertility drug use significantly impacts ovarian cancer risk when taking into account parity, gravidity, and cause of infertility.

METHODS

Data from the Hormones and Ovarian Cancer Prediction (HOPE) study were used (902 cases, 1,802 controls). Medical and reproductive histories were collected via in-person interviews. Logistic regression was used to calculate ORs and 95% confidence intervals (CI). Models were adjusted for age, race, education, age at menarche, parity, oral contraceptive use, breastfeeding, talc use, tubal ligation, and family history of breast/ovarian cancer.

RESULTS

Ever use of fertility drugs was not significantly associated with ovarian cancer within the total HOPE population (OR, 0.93; 95% CI, 0.65-1.35) or among women who reported seeking medical attention for infertility (OR, 0.87; 95% CI, 0.54-1.40). We did observe a statistically significant increased risk of ovarian cancer for ever use of fertility drugs among women who, despite seeking medical attention for problems getting pregnant, remained nulligravid (OR, 3.13; 95% CI, 1.01-9.67).

CONCLUSIONS

These results provide further evidence that fertility drug use does not significantly contribute to ovarian cancer risk among the majority of women; however, women who despite infertility evaluation and fertility drug use remain nulligravid, may have an elevated risk for ovarian cancer.

IMPACT

Our results suggest that fertility drug use does not significantly contribute to overall risk of ovarian cancer when adjusting for known confounding factors.

Gonadotropin signalling in epithelial ovarian cancer

Ovarian cancer is the most lethal of all gynecologic malignancies, although its aetiology remains poorly understood. A role for the gonadotropins, follicle-stimulating hormone (FSH) and luteinising hormone (LH), has been implicated in a variety of different aspects of ovarian cancer tumorigenesis, including cellular proliferation, migration and invasion. This review focuses on the latest advances in knowledge concerning signalling pathways and functional consequences of gonadotropin action, including changes in protein-, miRNA- and gene expression, in epithelial ovarian cancer cells.