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.

Fertility medications and the risk of cancer

Cancer is among the leading causes of death, and malignant diseases of the female genital tract are among the most common sites. Reproductive factors that are also associated with infertility have been identified as risk factors. Hormones are thought to play a role in the induction and promotion of some type of cancers. Hormonal preparations affect the endocrine milieu and, by acting on the reproductive organs themselves, could even have a direct effect on carcinogenesis. Numerous case-control and cohort studies have tried to determine whether fertility medication use increases cancer risk. Overall, the current data is reassuring but most research groups drew conclusions based on a small number of cases and after a relatively short follow-up. Proper counseling prior to fertility medication use is important and further studies on even larger patient groups with more cancer cases are needed to support widespread use of fertility medications.

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.

Meta-Analysis on the Possible Association Between In Vitro Fertilization and Cancer Risk

Objective

We aimed to examine the association between in vitro fertilization (IVF) and risk of cancers through conducting a meta-analysis of cohort studies.

Methods

Relevant studies were identified by using PubMed, ISI Web of knowledge, and Scopus through March 2012. Reference lists from retrieved articles were also reviewed. We included historical cohort studies that reported relative risks (RRs) with 95% confidence intervals (CIs) for the association between IVF and cancer risk. Both fixed- and random-effects models were used to calculate the summary risk estimates.

Results

Eight cohort studies involving 746,455 participants were included in this meta-analysis. The overall combined RRs for women with IVF treatment were 0.99 (95% CI, 0.74–1.32) for all-site cancer, 1.59 (95% CI, 1.24–2.03) for ovarian cancer, 0.89 (95% CI, 0.79–1.01) for breast cancer, and 1.07 (95% CI, 0.45–2.55) for cervical cancer. A beneficial effect was shown in the subgroup of breast cancer meta-analysis compared with women who gave birth (RR, 0.79; 95% CI, 0.65–0.95). Excess risk of ovarian cancer was still observed when analyses were restricted to studies with less than 8 years of follow-up (RR, 2.35; 95% CI, 1.03–5.37) and studies including cancer cases diagnosed within 1 year of the IVF treatment (RR, 1.71; 95% CI, 1.22–2.40). No evidence of substantial publication bias was observed.

Conclusions

This meta-analysis suggests that there is no significant association between IVF and cancer risk. A possible beneficial effect was shown in the subgroup of breast cancer meta-analysis. Excess risk of ovarian cancer was observed in the analysis of all the studies and subgroups. Special attention should be made to women who may be diagnosed with cancer during or shortly after IVF treatment. Studies of high methodological quality with larger population and longer follow-up are required to provide more evidences for a better understanding of the association.

Infertility treatment and the risk of cancer

BACKGROUND

A possible correlation between hormonal stimulation during treatment of infertility and the risk of cancer of the breast, the ovaries, the cervix or the uterus has been investigated in a number of epidemiological studies. The purpose of this article is to review the relevant literature and summarise the findings. KNOWLEDGE BASE: This review article is based on literature searches in the databases MEDLINE, Cochrane and EMBASE.

RESULTS

No studies showed a specific general correlation between hormonal ovulatory stimulation used as pre-treatment to assisted fertilisation and an increased risk of cancer of the breast, the ovaries, the cervix or the uterus. Most studies detected no increased risk. Some studies, however, showed an increased risk of cancer among certain sub-groups, such as women who have received repeated treatment with clomiphene citrate.

INTERPRETATION

On the basis of the studies reviewed, the conclusions are ambiguous. It is therefore necessary to monitor the long-term effects of infertility treatment on women's health. Further good-quality large-scale population studies are necessary, with longer follow-up periods and better adjustment for confounding factors.

Breast cancer and fertility

OPINION STATEMENT

The increased availability of assisted reproductive technologies (ART) allows women with fertility issues to increase their chances of a successful pregnancy with the use of medications that, in some cases, increase circulating estrogens. There has been significant concern that the use of these medications will increase the risk of hormone-sensitive cancers such as breast, ovarian and uterine malignancies. Additionally, for those women who are diagnosed with a breast cancer during their reproductive years, this diagnosis can be particularly difficult as future fertility is a major concern for many young breast cancer survivors. With the current available data, there does not appear to be a statistically significant increase in the risk of developing breast cancer with ART, although several series suggest a potential possible related increase in borderline ovarian and uterine cancers. For breast cancer survivors, there does not appear to be an increased risk of death associated with subsequent pregnancies when compared with breast cancer patients who did not have subsequent pregnancies, although waiting at least 2 years after the diagnosis of breast cancer potentially may convey a protective effect. Therefore, when systemic therapy for breast cancer is recommended, early counseling and referral to a reproductive endocrinologist is warranted to provide optimal fertility preservation options. Further safety and outcomes studies are warranted for children.

Fertility drugs and young-onset breast cancer: results from the Two Sister Study

BACKGROUND

Fertility drugs stimulate hyperovulation, which may have implications for breast cancer. We examined the association between use of fertility drugs (clomiphene citrate [CC] and follicle-stimulating hormone [FSH]) and subsequent risk of young-onset (<50 years at diagnosis) breast cancer.

METHODS

We conducted the Two Sister Study, a sister-matched case-control study, by enrolling 1422 women between September 2008 and December 2010, who were younger than age 50 years at diagnosis with breast cancer and were enrolled within 4 years of diagnosis, and 1669 breast cancer-free control sisters from the Sister Study. Participants reported their use of fertility drugs (CC and FSH) and ever-users reported whether a pregnancy had resulted that lasted 10 or more (10+) weeks. Conditional logistic regression was used to estimate confounder-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for fertility drug use with or without conception of a 10+ week pregnancy.

RESULTS

A total of 288 participants reported having used ovulation-stimulating drugs (193 CC only, 29 FSH only, and 66 both). Overall, women who had used fertility drugs showed a non-statistically significantly decreased risk of breast cancer, compared with nonusers (OR = 0.82, 95% CI = 0.63 to 1.08). Women who had used fertility drugs but had not conceived a 10+ week pregnancy under treatment showed a statistically significantly decreased risk of breast cancer compared with nonusers (OR = 0.62, 95% CI = 0.43 to 0.89). Women who had used fertility drugs and conceived a 10+ week pregnancy under treatment showed a statistically significantly increased risk of breast cancer compared with unsuccessfully treated women (OR = 1.82, 95% CI = 1.10 to 3.00), although their risk was not increased compared with women who had not used fertility drugs (OR = 1.13, 95% CI = 0.78 to 1.64).

CONCLUSIONS

In the absence of a 10+ week pregnancy under treatment, exposure to ovulation-stimulating fertility drugs was associated with reduced risk of young-onset breast cancer. This apparent association was absent in women who conceived a 10+ week pregnancy under treatment, for whom risk was higher than that of unsuccessfully treated women, but similar to that of untreated women.

In vitro fertilization and breast cancer: is there cause for concern?

OBJECTIVE

To examine the incidence rate of breast cancer in a cohort of women undergoing treatment for infertility, comparing the rate in women who had in vitro fertilization (IVF) with those who did not.

DESIGN

Population-based cohort study using linked hospital and registry data.

SETTING

Hospital.

PATIENT(S)

All women aged 20-44 years seeking hospital investigation and treatment for infertility in Western Australia during the period 1983-2002 (n = 21,025).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Hazard ratios (HRs) for breast cancer.

RESULT(S)

There was no overall increase in the rate of breast cancer in women who had IVF (HR 1.10, 95% confidence interval [CI] 0.88-1.36), but there was an increased rate in women who commenced IVF at a young age. Women who commenced hospital infertility treatment at 24 years and required IVF had an unadjusted HR of breast cancer of 1.59 (95% CI 1.05-2.42) compared with women of the same age who had infertility treatment but no IVF. When adjusted for late age at first delivery, which is associated with an increased rate of breast cancer, and delivery of twins and higher-order multiples, which is associated with a decreased rate of breast cancer, the HR remained elevated at 1.56 (95% CI 1.01-2.40). Hazard ratios were not elevated in women who commenced treatment at age 40 and required IVF (adjusted HR 0.87, 95% CI 0.62-1.22).

CONCLUSION(S)

Commencing IVF treatment at a young age is associated with an increased rate of breast cancer.

[Cancer, fertility preservation and gonadotropins]

The recent emergence of oncofertility raises the question of ovarian stimulation and its risks when performed for oocyte or/and embryo cryopreservation in a fertility preservation program. The relation between ovarian stimulation and cancer has been marked by the possible direct or indirect tumorigenic role for pituitary gonadotrophins in the tumorogenesis. Although the growth of many gonadal and extragonadal tumors is stimulated by gonadal sex hormones, whose production is regulated by gonadotrophins, there is still a lack of data to consider FSH and LH as tumor promoters. The purpose of this brief review is to present on one hand, the questions raised by the administration of exogenous gonadotrophins in cancer patients and on the other, to evaluate both experimental and clinical data about the possible relation between gonadotrophins and tumorogenesis.

Fertility drugs and the risk of breast and gynecologic cancers

The evaluation of cancer risk among patients treated for infertility is complex, given the need to consider indications for use, treatment details, and the effects of other factors (including parity status) that independently affect cancer risk. Many studies have had methodologic limitations. Recent studies that have overcome some of these limitations have not confirmed a link between drug use and invasive ovarian cancers, although there is still a lingering question as to whether borderline tumors might be increased. It is unclear whether this merely reflects increased surveillance. Investigations regarding breast cancer risk have produced inconsistent results. In contrast, an increasing number of studies suggest that fertility drugs may have a special predisposition for the development of uterine cancers, of interest given that these tumors are recognized as particularly hormonally responsive. Additional studies are needed to clarify the effects on cancer risk of fertility drugs, especially those used in conjunction with in vitro fertilization. Because many women who have received such treatments are still relatively young, further monitoring should be pursued in large well-designed studies that enable assessment of effects within a variety of subgroups defined by both patient and disease characteristics.

Risk of borderline and invasive ovarian tumours after ovarian stimulation for in vitro fertilization in a large Dutch cohort

BACKGROUND

Long-term effects of ovarian stimulation for IVF on the risk of ovarian malignancies are unknown.

METHODS

We identified a nationwide historic cohort of 19,146 women who received IVF treatment in the Netherlands between 1983 and 1995, and a comparison group of 6006 subfertile women not treated with IVF. In 1997-1999, data on reproductive risk factors were obtained from 65% of women and data on subfertility (treatment) were obtained from the medical records. The incidence of ovarian malignancies (including borderline ovarian tumours) through 2007 was assessed through linkage with disease registries. The risk of ovarian malignancies in the IVF group was compared with risks in the general population and the subfertile comparison group.

RESULTS

After a median follow-up of 14.7 years, the risk of borderline ovarian tumours was increased in the IVF group compared with the general population [standardized incidence ratio (SIR) = 1.76; 95% confidence interval (CI) = 1.16-2.56]. The overall SIR for invasive ovarian cancer was not significantly elevated, but increased with longer follow-up after first IVF (P = 0.02); the SIR was 3.54 (95% CI = 1.62-6.72) after 15 years. The risks of borderline ovarian tumours and of all ovarian malignancies combined in the IVF group were significantly increased compared with risks in the subfertile comparison group (hazard ratios = 4.23; 95% CI = 1.25-14.33 and 2.14; 95% CI = 1.07-4.25, respectively, adjusted for age, parity and subfertility cause).

CONCLUSIONS

Ovarian stimulation for IVF may increase the risk of ovarian malignancies, especially borderline ovarian tumours. More large cohort studies are needed to confirm these findings and to examine the effect of IVF treatment characteristics.

Autoantibodies to mesothelin in infertility

BACKGROUND

According to extensive epidemiologic data, infertility is associated with increased ovarian cancer risk. Previous studies showed that both women with infertility and those with ovarian cancer have autoantibodies to ovarian antigens. The objective was to determine if women with infertility have antibodies to mesothelin, a well-characterized ovarian cancer antigen.

METHODS

Sera were obtained from women with infertility (n = 109), ovarian cancer (n = 28), benign ovarian tumors or cysts (n = 24), and from healthy women (n = 152). Infertility included those with a risk for ovarian cancer; endometriosis (n = 23), ovulatory dysfunction (n = 17), premature ovarian failure (POF; n = 25) and unexplained infertility (n = 44). Sera were assayed for mesothelin antibodies and for circulating mesothelin antigen by immunoassay and compared with assay control sera (n = 16) to determine a positive result.

RESULTS

Mesothelin antibodies were significantly more frequent in women with prematurely reduced ovarian function including ovulatory dysfunction (59%), ovarian failure (44%) and unexplained infertility (25%) compared with controls. In contrast, women with endometriosis, who also have a high risk for ovarian cancer, did not have mesothelin antibodies. Serum levels of mesothelin were rarely elevated in women with infertility but were high in most patients with ovarian cancer.

CONCLUSIONS AND IMPACT

We show for the first time that antibodies to mesothelin, a well-characterized ovarian cancer antigen, occur in some women with epidemiologic risk for ovarian cancer. The results suggest it may be possible to identify which women with infertility have ovarian cancer risk.

Maternal and child outcome after in vitro fertilization--a review of 25 years of population-based data from Sweden

OBJECTIVE

To summarize data on deliveries after in vitro fertilization (IVF) performed in Sweden up to 2006.

DESIGN

Cohort study of women and children, conceived after IVF, with comparisons of deliveries after IVF before and after 1 April 2001.

SETTING

Study based on Swedish health registers.

POPULATION

Births registered in the Swedish Medical Birth Register with information on IVF from all IVF clinics in Sweden.

METHODS

Results from the second study period are summarized, and outcomes between the two periods are compared. Long-term follow-up is based on data from both periods.

MAIN OUTCOME MEASURES

Maternal and perinatal outcomes, long-term sequels.

RESULTS

Some maternal pregnancy complications decreased in rate, notably pre-eclampsia and premature rupture of membranes. The rate of multiple births and preterm births decreased dramatically, with a better neonatal outcome, including reduced neonatal mortality. No difference in outcome existed between IVF and intracytoplasmic sperm injection or between the use of fresh and cryopreserved embryos, but children born after blastocyst transfer had a slightly higher risk for preterm birth and congenital malformations than children born after cleavage stage transfer. An increased risk for cerebral palsy, possibly for attention deficit and hyperactivity disorder, for impaired visual acuity and for childhood cancer was noted, but these outcomes were rare also after IVF. An increased risk for asthma was demonstrated. No effect on maternal cancer risk was seen.

CONCLUSION

A marked decrease in multiple births was the main reason for better pregnancy and neonatal outcome and may also have a beneficial effect on long-term results, notably cerebral palsy.