Ovarian cancer and fertility medications: a critical appraisal

Integrated analysis of transcriptomic and metabolomic data demonstrates the significant role of pyruvate carboxylase in the progression of ovarian cancer

The aim of this study was to explore prognosis-related biomarkers and underlying mechanisms during ovarian carcinoma progression and development. mRNA expression profiles and GSE49997 dataset were downloaded. Survival analyses were performed for genes with high expression levels. Expression level of candidate genes was explored in four ovarian cancer cells lines. Pyruvate carboxylase (PC) was found to be one of significantly differentially expressed gene (DEG). The role of PC knockdown was analyzed in SKOV cells using cell proliferation, flow cytometric, and Transwell migration and invasion assays. DEGs and metabolites in PC-shRNA (shPC)-treated samples vs. control groups were identified. PC was a prognosis-related gene and related to metabolic pathway. Knockdown of PC regulated cell proliferation, cell cycle progression, and migration and invasion of SKOV-3 cells. Transcriptome sequencing analyses showed STAT1 and TP53 gained higher degrees in PPI network. A total of 44 metabolites were identified. These DEGs and metabolites in PC samples were related with neuroactive ligands receptor interaction, glycine, serine and threonine metabolism, and ABC transporter pathways. PC may affect the tumor biology of ovarian cancer through the dysregulation of glycine, serine, and threonine metabolism, and ABC transporter pathways, as well as STAT1 and TP53 expression.

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The original review included published and unpublished observational studies from 1990 to February 2013.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.

The determination of possible genetic damage to women undergoing in vitro fertilization due to infertility caused by the male factor

In this study, we aimed at determining possible genetic damage to women who were exposed to in vitro fertilization (IVF) due to infertility with male factor. Four different genotoxicity tests were used in human lymphocytes in this study with regard to chromosomal aberration (CA), sister chromatid exchange (SCE), micronucleus (MN), and comet tests. There was a statistically significant increase in sister chromatid exchange (SCE) test in the study group compared with the control group. In addition, a higher rate of MN frequency was determined only in the 21–30 age range study group compared with the control group in the same age range. On the other hand, MN frequency did not differ significantly between the control and total study groups. In addition, there was no significant difference between the control group and the study group in terms of mitotic (MI), replication (RI), and nuclear division (NDI) indices. Furthermore, there was no statistically significant increase for chromosomal aberration and DNA damage to the study groups. Our results showed that in vitro fertilization treatments have a weak risk at the genetic level in cultured human lymphocytes.

Fertility treatments and invasive epithelial ovarian cancer risk in Jewish Israeli BRCA1 or BRCA2 mutation carriers

OBJECTIVE

To determine whether BRCA mutation carriers who undergo fertility treatments are at increased risk of developing invasive epithelial ovarian cancer (IEOC).

DESIGN

Historical cohort study.

SETTING

Tertiary university-affiliated medical center and the National Cancer Registry.

PATIENT(S)

A total of 1,073 Jewish Israeli BRCA mutation carriers diagnosed in a single institution between 1995 and 2013, including 164 carriers (15.2%) who had fertility treatments that included clomiphene citrate (n = 82), gonadotropin (n = 69), in vitro fertilization (IVF) (n = 66), or a combination (n = 50), and 909 carriers not treated for infertility.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Odds ratios (OR) and 95% confidence intervals (CI) for IEOC association with fertility treatments and other hormone and reproductive variables.

RESULT(S)

In 175 (16.3%) mutation carriers, IEOC was diagnosed; 139 women carried BRCA1, 33 carried BRCA2, and 3 had unknown mutations. Fertility treatments were not associated with IEOC risk (age-adjusted OR 0.63; 95% CI, 0.38-1.05) regardless of treatment type (with clomiphene citrate, OR 0.87; 95% CI, 0.46-1.63; with gonadotropin, OR 0.59; 95% CI, 0.26-1.31; with IVF, OR 1.08, 95% CI, 0.57-2.06). Multivariate analysis indicated an increased risk of IEOC with hormone-replacement therapy (OR 2.22; 95% CI, 1.33-3.69) and a reduced risk with oral contraceptives (OR 0.19; 95% CI, 0.13-0.28) in both BRCA1 and BRCA2 mutation carriers. Parity was a risk factor for IEOC by univariate but not multivariate analysis.

CONCLUSION(S)

According to our results, treatments for infertile BRCA mutation carriers should not be contraindicated or viewed as risk modifiers for IEOC. Parity as a risk factor in BRCA mutation carriers warrants further investigation.

Endometriosis and ovarian cancer

Endometriosis is the leading cause of morbidity among premenopausal women and the complex pathogenesis of this disease remains controversial despite extensive research. This disease represents one of the most common gynecological problems. It is generally believed that this disease is due primarily to retrograde menstruation or transplantation of shed endometrium. Based on overwhelming data, ovarian endometrioma is considered a neoplastic process, since most endometriosis-associated ovarian carcinoma occur in the presence of atypical ovarian endometriosis. A study comparing patients with typical epithelial ovarian cancer with endometriosis-associated ovarian cancer demonstrated that the patients with the latter disease strongly differ in both biological and histological characteristics. The prevelance of this disease is not completely established, but approximately 15 percent of women suffer from this disease. In addition, we know about the possible links between endometriosis and cancer for almost 100 years. Despite clear evidence revealing that endometriosis increases ovarian cancer risks, it is possible that it may not affect disease progression after the appearance of ovarian cancer. However, despite clear evidence revealing that endometriosis increases ovarian cancer risk, our knowledge of the risk factors is far from established. In our review, we focused on the most recent approaches including possible biomarkers and genetic approaches.

In vivo evaluation of the genotoxic effects of gonadotropins on rat reticulocytes

BACKGROUND

Gonadotropins, as ovulation-inducing drugs, have been used widely to treat infertility. An epidemiologic correlation between infertility therapy and ovarian cancer development has been reported. However, the effect of gonadotropins in the formation of reproductive tract cancers is controversial.

OBJECTIVE

The aim of the study was to determine the in vivo genotoxic effects of gonadotropins on rat reticulocytes.

METHODS

In this prospective, randomized, controlled study, rats were randomly assigned to 1 of 5 groups. The calculated rat doses of 0.65 human menopausal gonadotropin (hMG), 0.95 hMG, 0.65 follitropin beta (FB), 0.95 FB, or normal saline (control group) were injected, respectively. These calculated rat doses (U/g) are based on average human gonadotropin doses of 150 and 225 IU/d for a 70-kg woman given in 2-mL saline (the control group received 2 mL of saline). Injections were administered once per day for 5 days, followed by 5 days of rest. Each treatment was repeated for 6 estrus cycles in the rats for a total of 12 estrus cycles. Six months after the last day of the 12(th) cycle, the rats were euthanized. Bone marrow tissues were removed, and pluripotent reticulocyte cells with micronuclei, nuclear buds, and binuclear abnormalities were analyzed using an in situ micronuclei assay under light microscopy. The proportion of micronucleated cells, cells with anaphase bridge, nuclear buds, and other nuclear abnormalities were measured.

RESULTS

The number of cells with nuclear buds and binuclear abnormalities in the hMG 225 and FB 225 groups was significantly higher (P < 0.05) than that from the hMG 150, FB 150, and control groups in the cytogenetic analysis of bone marrow stem cells. An increased rate of genotoxicity in all gonadotropin groups versus that of placebo was found.

CONCLUSION

In rats, the micronucleus genotoxicity assay suggests a dose-dependent gonadotropin effect on genomic instability in bone marrow stem cells in vivo.

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.

Benefits and risks of ovarian function and reproduction for cancer development and prevention

Ovarian function and menstrual cycle disturbances, pregnancy, and reproductive medicine procedures can either increase gynecological cancer risk or prevent cancer development. For ovarian cancer development, there are two hypotheses, which are connected with ovulation and gonadotropin secretion. Most of the ovarian cancers seem to be derived from displaced ovarian surfice epithelial cells. One year of ovulatory cycles increases the ovarian cancer risk by 6%. Ovulation between 22 and 29 years of age causes the highest risk increase per year. In contrast, progesterone or progestins appear to create protection. Lifestyle can affect or modify ovarian cancer risk. Breast cancer risk is very much related to age of menarche and menopause, pregnancy, and breast feeding. All of which are related to ovarian function and progestogenic impact that translates either into breast cancer risk increase or decrease. This is modified by body mass index, physical activity, and lifestyle in general. The risk of endometrial cancer is most closely related to endogenous progesterone during the menstrual cycle and pregnancy or by exogenous progestogens as in oral contraceptives. These effects are progestogen dose and time dependent. Endometrial cancer risk can also be increased by estrogen-producing tumors or long-term estrogen treatment.

Identification of common mechanisms between endometriosis and ovarian cancer

PURPOSE

To determine common molecular markers between endometriosis and ovarian cancer.

METHODS

Patients included women who underwent laparoscopic excision of ovarian endometriotic lesions (n = 7), healthy non-pregnant women with normal pelvises, who underwent excision of normal peritoneum (n = 7). Two epithelial ovarian cancer (EOC) cell lines were also utilized. Expression of transforming growth factor (TGF)-β1, cyclooxygenase (COX)-2, vascular endothelial growth factor (VEGF), estrogen receptor (ER)-1α, progesterone receptor (PR), androgen receptor (AR), and aromatase was evaluated by real-time RT-PCR.

RESULTS

Endometriosis and EOC cells manifested significantly higher mRNA levels of TGF-β1, COX-2, VEGF, ER-1α, AR, and aromatase, while they expressed significantly lower mRNA levels of PR.

CONCLUSIONS

Increased TGF-β1, COX-2, VEGF, ER-1α, AR, and aromatase and decreased PR in endometriotic as well as EOC cells suggests a potential association between these two disease processes. This association is important, as it may reveal common mechanisms for both diseases.

Fertility preservation for cancer patients: a review

Infertility can arise as a consequence of treatment of oncological conditions. The parallel and continued improvement in both the management of oncology and fertility cases in recent times has brought to the fore-front the potential for fertility preservation in patients being treated for cancer. Oncologists must be aware of situations where their treatment will affect fertility in patients who are being treated for cancer and they must also be aware of the pathways available for procedures such as cryopreservation of gametes and/or embryos. Improved cancer care associated with increased cure rates and long term survival, coupled with advances in fertility treatment means that it is now imperative that fertility preservation is considered as part of the care offered to these patients. This can only be approached within a multidisciplinary setting. There are obvious challenges that still remain to be resolved, especially in the area of fertility preservation in prepubertal patients. These include ethical issues, such as valid consent and research in the area of tissue retrieval, cryopreservation, and transplantation.

Safety of drugs used in assisted reproduction techniques

Infertility may affect one in six couples; however, the development of the assisted reproduction technique (ART) created the opportunity for a large proportion of the infertile population to bear children. Pharmacological agents are routinely used in ART, and new ones are introduced regularly, with the aim of retrieving multiple oocytes to increase the prospect of pregnancy. The combinations of drugs that are used have specific adverse effects, but it is mostly the combined action of more than one agent that causes the greatest concern. The matter is complicated by the suspicion that some techniques in ART, for example intracytoplasmic sperm injection for severe male infertility problems (including azoospermia), may also contribute to the increase in adverse effects, especially congenital malformation. Gonadotropin releasing hormone (GnRH) agonists are widely used in controlled ovarian hyperstimulation. It may give rise to a short period of estradiol withdrawal symptoms and it may also lead to luteal phase deficiency. Similarly GnRHa antagonists, which have been recently introduced to control ovarian hyperstimulation, can lead to luteal phase deficiency and may cause some local injection site reactions. The more pure form of gonadotropin leads to less local injection site reactions and their main adverse effects are associated with the consequences of multiple ovulations. It has been proposed that gonadotropins may be a factor in the increasing risk of ovarian cancer and possibly breast cancer, but this has not been substantiated. Prion infection is another potential hazard, although no cases have been reported. Ovarian hyperstimulation syndrome is a well recognised complication of controlled ovarian hyperstimulation in ART. It is usually a result of recruitment of a large number of ovarian follicles. Efforts to minimise the incidence of this syndrome and its severity are now well developed. Congenital malformations are another possible adverse effect of fertility drugs, but it is more probable that the increase in congenital abnormality that is reported in ART is because of the population studied, i.e. patients already at high risk of congenital malformation, rather than the fertility drugs used or the technique employed. High order multiple pregnancy and its sequela is a well established complication of controlled ovarian hyperstimulation. This could be a result of multiple ovulations or more than one embryo replacement. Reducing the number of embryos transferred can reduce this more serious adverse effect for expectant mothers and for children conceived from ART.

In vivo Evaluation of the Genotoxic Effects of Clomiphene Citrate on Rat Reticulocytes: A Micronucleus Genotoxicity

OBJECTIVE

To determine the genotoxic effects of clomiphene citrate (CC) on rat reticulocytesin vivo.

METHODS

In this prospective, randomized, controlled study, rats were each assigned randomly to the CC 50, CC 100, CC 200, or control group and were given repeat doses of 0.16, 0.32 or 0.64 mg CC, or normal saline, respectively. Each study group received its CC dose in 2 ml of saline intraperitoneally for 5 days, while the control group received only 2 ml of saline. Each treatment cycle was repeated six times. Six months later, the rats were euthanized. Bone marrow tissues were removed, and pluripotent reticulocyte cells with micronuclei, nuclear buds, and binuclear abnormalities were analyzed using an in situmicronuclei assay under light microscopy. The proportion of micronucleated erythrocytes was measured.

RESULTS

Fewer cells with nuclear buds and binuclear abnormalities were detected in the CC 50 group and controls. The CC 100 and 200 groups had significantly (p < 0.05) more nuclear buds and binuclear abnormalities compared with the CC 50 group and controls in the cytogenetic analysis of bone marrow stem cells.

CONCLUSION

In rats, the micronucleus genotoxicity assay suggests a dose-dependent CC effect on genomic instability in bone marrow stem cells in vivo.

Recurrent implantation failure in assisted reproduction: how to counsel and manage. A. General considerations and treatment options that may benefit the couple

Recurrent implantation failure is a distressing phenomenon, both for the infertile couple and for the physician responsible for their treatment. Aetiology is often not clear and treatment options are vague. Particularly when transferred embryos are of good quality, recurrent implantation failure may be attributed to less than optimal embryo transfer technique, pathological lesions of the uterine cavity, the presence of hydrosalpinges, fibroids and endometriosis. Poor embryo quality, especially when repetitive, is a major impediment to successful implantation and cannot be corrected at the present time. Molecular abnormalities at the endometrial level and abnormal embryo-endometrium dialogue may be responsible for some cases of recurrent implantation failure. Furthermore, there may be over- or under-expressed genes that may be related to successful implantation. At the present time, the physician confronted with a couple presenting with recurrent implantation failure should discuss openly the potential causes of this phenomenon, with special emphasis on correctable causes, and offer remedies that are evidence based.

Safety and efficacy of infertility treatment after conservative management of borderline ovarian tumors: A preliminary report

OBJECTIVE

To evaluate the safety and efficacy of infertility treatment in a group of patients after conservative management of borderline ovarian tumors.

DESIGN

Retrospective study.

SETTING

University IVF unit.

PATIENT(S)

Five patients with previous conservative treatment of borderline ovarian tumor.

INTERVENTION(S)

Seventeen IVF cycles.

MAIN OUTCOME MEASURE(S)

Recurrence, IVF outcome.

RESULT(S)

At the time of diagnosis, the mean age of the patients was 32.2 +/- 6.9 years. The mean time elapsed between the initial diagnosis of a borderline tumor and the performance of IVF was 42.2 months. After IVF, the mean number of oocytes retrieved was 7.9 +/- 4.0 with a mean fertilization rate of 57.1% and a mean number of 3.1 +/- 1.4 day 3 embryos transferred. Six pregnancies were achieved in three of the five patients with a pregnancy rate per retrieval of 37.5% and per transfer of 42.9%. The mean follow-up time that elapsed since the first IVF cycle was 39.2 months (range 9-78 months). One patient had three recurrences 13, 27, and 43 months after her first IVF cycle, all of which remained histologically serous borderline tumor. All patients were without evidence of disease at the time of last follow-up.

CONCLUSION(S)

At a mean follow-up time of 39.2 months, our results suggest that IVF may be considered for patients with conservatively treated borderline tumors. Furthermore, overall IVF success rates were very satisfactory, suggesting no perceptible negative impact of prior borderline ovarian neoplasia on pregnancy rates after IVF.