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

Infertility and risk of postmenopausal breast cancer in the women's health initiative

PURPOSE

Although infertility (i.e., failure to conceive after ≥ 12 months of trying) is strongly correlated with established breast cancer risk factors (e.g., nulliparity, number of pregnancies, and age at first pregnancy), its association with breast cancer incidence is not fully understood. Previous studies were primarily small clinic-based or registry studies with short follow-up and predominantly focused on premenopausal breast cancer. The objective of this study was to assess the relationship between infertility and postmenopausal breast cancer risk among participants in the Women's Health Initiative (analytic sample = 131,784; > 25 years of follow-up).

METHODS

At study entry, participants were asked about their pregnancy history, infertility history, and diagnosed reasons for infertility. Incident breast cancers were self-reported with adjudication by trained physicians reviewing medical records. Cox proportional hazards models were used to estimate risk of incident postmenopausal breast cancer for women with infertility (overall and specific infertility diagnoses) compared to parous women with no history of infertility. We examined mediation of these associations by parity, age at first term pregnancy, postmenopausal hormone therapy use at baseline, age at menopause, breastfeeding, and oophorectomy.

RESULTS

We observed a modest association between infertility (n = 23,406) and risk of postmenopausal breast cancer (HR = 1.07; 95% CI 1.02-1.13). The association was largely mediated by age at first term pregnancy (natural indirect effect: 46.4% mediated, CI 12.2-84.3%).

CONCLUSION

These findings suggest that infertility may be modestly associated with future risk of postmenopausal breast cancer due to age at first pregnancy and highlight the importance of incorporating reproductive history across the life course into breast cancer analyses.

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 increased risk of cancer because of factors (endometriosis and unopposed estrogen) associated with infertility, the low incidence of most of these cancers, and that the diagnosis of cancer is typically several years after fertility drug use. On the basis of available data, there does not appear to be an association between fertility drugs and breast, colon, or cervical cancer. There is no conclusive evidence that fertility drugs increase the risk of uterine cancer, although women with infertility are at higher risk of uterine cancer. There are insufficient data to comment on the risk of melanoma and non-Hodgkin lymphoma associated with fertility drug use. Women should be informed that there may be an increased risk of invasive and borderline ovarian cancers and thyroid cancer associated with fertility treatment. It is difficult to determine whether this risk is related to underlying endometriosis, female infertility, or nulliparity.

History of infertility and risk of breast cancer: a prospective cohort study

PURPOSE

Research on infertility and risk of breast cancer has been conflicting, potentially because many well-established breast cancer risk factors, such as pregnancy history, are strongly correlated with infertility.

METHODS

We followed participants in the Nurses' Health Study II from 1989 to 2015 (n = 103,080) for the development of invasive breast cancer and calculated Hazard Ratios (HR) and 95% confidence intervals (CI) using Cox regression. Participants with a self-reported history of infertility (12 months of trying without conception) were compared to gravid women with no history of infertility. We classified breast cancer by menopausal status and investigated mediation by reproductive factors.

RESULTS

Over 26 years of follow-up, 26,208 (25.4%) women reported a history of infertility, and 3,201 women were newly diagnosed with invasive breast cancer. We observed no association between infertility history and risk of overall breast cancer (HR: 1.05, 95% CI: 0.97-1.14) or premenopausal breast cancer (RR: 0.93, 95% CI: 0.83-1.03). However, we observed a modest association between history of infertility and risk of postmenopausal breast cancer (HR: 1.13, 95% CI: 1.00-1.28), approximately 50% of which could be attributed to lower total parity and later age at first birth (95% CI: 8.2%-91.0%).

CONCLUSIONS

Women with a history of infertility were at increased risk of postmenopausal breast cancer. Older age at first birth and lower total parity explained approximately half of the association between infertility and risk of postmenopausal breast cancer.

Hospitalizations up to 8 years following delivery in assisted reproductive technology-treated and subfertile women

OBJECTIVE

To investigate hospitalizations up to 8 years after live birth among women who used assisted reproductive technology (ART) or who were subfertile compared with women who conceived naturally.

DESIGN

Retrospective cohort.

SETTING

Deliveries among privately insured women aged ≥18 years between 2004 and 2017 from Massachusetts state vital records were linked to the Society for Assisted Reproductive Technology Clinic Outcome Reporting System and hospital observational/inpatient stays.

PATIENT(S)

We compared patients with ART, medically assisted reproduction (MAR), and unassisted subfertile (USF) delivery with those with fertile delivery.

INTERVENTION(S)

NA.

MAIN OUTCOME MEASURE(S)

Postdelivery hospitalization information was derived from the International Classification of Diseases codes for discharges and combined by type. The relative risks and 95% confidence intervals (CIs) of hospitalization for up to the first 8 years postdelivery were modeled.

RESULT(S)

Among 492,515 deliveries, 5.6% used ART, 1.6% used MAR, and 1.8% were USF. Compared with fertile deliveries, deliveries that used ART or MAR or were USF were more likely to have hospital utilization (inpatient or observational stay) for any reason for up to 8 years of follow-up (USF, adjusted relative risk [aRR], 1.18 [95% CI, 1.12-1.25]; MAR, aRR, 1.20 [1.13-1.27]; and ART, aRR, 1.29 [1.25-1.34]). Assisted reproductive technology deliveries had an increased risk of hospitalization for conditions of the cardiovascular system (aRR, 1.31 [95% CI, 1.20-1.41]), overweight/obesity (aRR, 1.30 [1.17-1.44]), diabetes (aRR, 1.25 [1.05-1.49]), reproductive tract (aRR, 1.62 [1.47-1.79]), digestive tract (aRR, 1.39 [1.30-1.49]), thyroid (aRR, 2.02 [1.80-2.26]), respiratory system (aRR, 1.13 [1.03-1.24]), and cancer (aRR, 1.40 [1.18-1.65]) up to 8 years after delivery. Deliveries with MAR and subfertility had similar patterns of hospitalization as ART deliveries.

CONCLUSION(S)

Women who conceived through fertility treatment or experienced subfertility were at increased risk of subsequent hospitalization resulting from a variety of chronic and acute conditions.

OUP accepted manuscript

Background

The significance of exogenous hormone manipulation as part of fertility treatment and its relationship to the development of breast cancer remains uncertain. Several historical reviews have been performed with conflicting results. This study is an updated meta-analysis to determine whether there is a causal relationship between different fertility treatments and breast cancer.

Methods

The study report is based on the guidelines of PRISMA and Meta-Analysis of Observational Studies in Epidemiology. Studies published within the last 20 years were included to reflect up to date in vitro fertilization (IVF) practice. This study was prospectively registered on PROSPERO on 07/04/2021, registration identification CRD42021247706. The primary outcome of the study was to determine whether there is an increased incidence of breast cancer in women treated with hormonal fertility treatment. The secondary outcomes were to determine whether fertility treatments were individually associated with excess breast-cancer risk.

Results

Overall, 25 studies, including 617 479 participants, were eligible for inclusion. There was no significant breast-cancer risk association with fertility treatment (compared with general and subfertility reference groups). Summary odds ratio of all included studies was 0.97 (95 per cent c.i. 0.90 to 1.04). Women who received six or more IVF cycles did not have an increased risk of breast cancer. Similarly, there was no excess breast-cancer risk associated with clomiphene, human chorionic gonadotropin, gonadotropin analogues and progesterone when examined individually. Comparably, there was no significant association between fertility treatment and excess breast-cancer risk in patients with more than 10 years’ follow-up. Summary odds ratio was 0.97 (95 per cent c.i. 0.85 to 1.12).

Conclusion

This meta-analysis did not find a significant association between fertility treatments and excess breast-cancer risk. Women considering IVF should be informed that it does not appear to increase breast-cancer risk.

The Impact of Exogenous Estrogen Exposure on the Characteristics and Outcome of Estrogen Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Early-Stage Breast Cancer

INTRODUCTION

The impact of exogenous estrogen exposure on breast cancer characteristics and outcomes is not well described. We aimed to investigate the effect of prior treatment with oral contraceptives (OCT), hormone replacement therapy (HRT), and fertility treatments on early-stage, estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer.

METHODS

This is a single-center retrospective cohort study comprising all women with ER-positive, HER2-negative, early breast cancer whose tumors were sent to Oncotype DX analysis between 2005 and 2012. Data on prior exposures to OCT, HRT, and fertility treatments were collected. The impact of these exposures on prespecified histopathological features was assessed including tumor size, nodal status, intensity of the hormonal receptors, grade, Oncotype recurrence score, Ki67, and lymphovascular and perineural invasion. The impact of these exposures on disease-free survival (DFS) and overall survival (OS) was also evaluated.

RESULTS

A total of 620 women were included, of which 19% had prior exposure to OCT, 30% to HRT, and 11% to fertility treatments. OCT use was associated with smaller (≤1 cm) tumors (p = 0.023) and were less likely to have grade 3 disease (p = 0.049). No other associations were found between exogenous estrogen exposure and tumor characteristics. Median follow-up was 10.4 years. Ten-year DFS was 85.7%, and it was not influenced by exogenous exposure. Ten-year OS was 90.2%, and OCT was associated with improved OS in univariate analysis (HR = 0.31, 95% CI: 0.11-0.85), but this difference did not remain significant in multivariate analysis (p = 0.275).

CONCLUSION

The impact of exogenous estrogen exposure on ER-positive, HER2-negative early breast cancer characteristics is limited. In the long term, none of the evaluated exposures had negative effect on DFS and OS.

Employment After Breast Cancer Diagnosis and Treatment Among Women in the Sister and the Two Sister Studies

Purpose Women undergoing diagnosis and treatment for breast cancer may face challenges in employment. We investigated the impact of demographic, clinical, workplace, and psychosocial characteristics on loss of employment after a breast cancer diagnosis and treatment. We further describe changes in work status and work environment for cancer survivors who sustain employment. Methods We analyzed responses from a survey of breast cancer survivors from the Sister Study and the Two Sister Study cohorts who reported being employed at the time of their breast cancer diagnosis and who reported employment status (lost vs. sustained employment) at the time of survey administration. Multivariate logistic regression was used to identify the effects of lymphedema, neuropathy, problems with memory or attention, social support, health insurance, and sick leave on lost employment, adjusting for demographic characteristics, cancer stage, treatment, and general health. Results Of the 1675 respondents who reported being employed at the time of diagnosis, 83.5% reported being 'currently' employed at the time of the survey. Older age, peripheral neuropathy, lack of sick leave, late stage at diagnosis, a recurrence or a new cancer, problems with memory or attention, and poor general health were significantly associated with lost employment. Conclusions The long-term effects of breast cancer treatment and workplace provisions for leave and accommodation may have a substantial effect on women's ability to sustain employment. The findings from this study highlight challenges reported by cancer survivors that may inform clinical and occupational interventions to support survivors' return to work.

Risk of breast cancer in women treated with ovarian stimulation drugs for infertility: a systematic review and meta-analysis

OBJECTIVE

To evaluate the evidence addressing the association between the use of ovarian stimulation drugs and the risk of breast cancer.

DESIGN

Systematic review and meta-analysis.

SETTING

Not applicable.

PATIENT(S)

Women without any previous history of breast cancer undergoing ovarian stimulation.

INTERVENTION(S)

Electronic databases were searched from 1990 until January 2020. All cohort studies reporting new incidences of breast cancer in infertile women using ovarian stimulating drugs were included. Treated (exposed) infertile women were compared with the unexposed general population with unexposed infertile women as controls.

MAIN OUTCOME MEASURE(S)

New diagnosis of breast cancer within an infertile and general population after exposure to ovarian stimulation drugs.

RESULT(S)

Overall, the quality of evidence was very low because of the serious risk of bias and indirectness (nonrandomized studies). There was no significant increase in the risk of breast cancer among women treated with any ovarian stimulation drug for infertility compared with that in unexposed controls from the general population and the infertile population (pooled odds ratio 1.03, 95% Confidence interval 0.86 to 1.23, 20 studies, I² = 88.41%, very low quality of evidence). Furthermore, no significant increase in the risk of breast cancer was found with the use of clomiphene citrate or gonadotropins, alone or in combination.

CONCLUSION(S)

The current study found that the use of clomiphene citrate and gonadotropins in infertile women was not associated with an increased risk of breast cancer.

Breast Cancer-Related Employment Disruption and Financial Hardship in the Sister Study

Background

More than one-half of breast cancer cases are diagnosed among women aged younger than 62 years, which may result in employment challenges. This study examined whether cancer-related employment disruption was associated with increased financial hardship in a national US study of women with breast cancer.

Methods

Women with breast cancer who were enrolled in the Sister or Two Sister Studies completed a survivorship survey in 2012. Employment disruption was defined as stopping work completely or working fewer hours after diagnosis. Financial hardship was defined as: 1) experiencing financial problems paying for cancer care, 2) borrowing money or incurring debt, or 3) filing for bankruptcy because of cancer. Prevalence ratios and 95% confidence intervals for the association between employment disruption and financial hardship were estimated using multivariable Poisson regression with robust variance.

Results

We analyzed data from women employed at diagnosis (n = 1628). Women were a median age of 48 years at diagnosis and 5.6 years from diagnosis at survey completion. Overall, 27.3% of women reported employment disruption (15.4% stopped working; 11.9% reduced hours), and 21.0% experienced financial hardship (16.0% had difficulty paying for care; 12.6% borrowed money or incurred debt; 1.8% filed for bankruptcy). In adjusted analysis, employment disruption was associated with nearly twice the prevalence of financial hardship (prevalence ratio = 1.93, 95% confidence interval = 1.58 to 2.35).

Conclusions

Women experiencing employment disruptions after breast cancer may be more vulnerable to financial hardship. Findings highlight the need to target risk factors for employment disruption, facilitate return to work or ongoing employment, and mitigate financial consequences after cancer.

Health-related quality of life outcomes among breast cancer survivors

BACKGROUND

Data from a nationwide sample of US breast cancer survivors were used to examine associations between patient characteristics (breast cancer clinical features, prognostic factors, and treatments) and health-related quality of life (HRQOL). Associations between postdiagnosis HRQOL and mortality were then evaluated.

METHODS

The authors identified female breast cancer survivors (n = 2453) from the Sister Study or Two Sister Study who were at least 1 year from breast cancer diagnosis and who had responded to a survivorship survey in 2012. HRQOL was assessed with the Patient-Reported Outcomes Measurement Information System (PROMIS) Global 10 measures. Multivariable linear regression was used to assess predictors associated with HRQOL. Cox regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between HRQOL and all-cause mortality.

RESULTS

HRQOL, assessed an average of 4.9 years after the cancer diagnosis (standard deviation of 1.9 years), was negatively associated with a higher cancer stage at diagnosis; a higher comorbidity score at the survey; experience of surgical complications; dissatisfaction with breast surgery; and experience of any recent recurrence, metastasis, or secondary malignancy. Since the completion of the survey, there were 85 deaths (3.5%) during a mean follow-up of 4 years (standard deviation of 0.5 years). In multivariate models, decreases in PROMIS physical T scores and mental T scores were associated with increased mortality (HR for physical T scores, 1.08; 95% CI, 1.05-1.11; HR for mental T scores, 1.03; 95% CI, 1.01-1.06).

CONCLUSIONS

Prognostic and cancer treatment-related factors affect HRQOL in breast cancer survivors and may inform targeted survivorship care. PROMIS global health measures may offer additional insights into patients' well-being and mortality risk.

LAY SUMMARY

Findings from a study suggest that prognostic and cancer treatment-related factors affect health-related quality of life (HRQOL) in breast cancer survivors and that poor HRQOL may increase the mortality risk. The evaluation of HRQOL is important because it may hold potential as a tool for optimizing survivorship care.

Toenail-Based Metal Concentrations and Young-Onset Breast Cancer

Several metals have carcinogenic properties, but their associations with breast cancer are not established. We studied cadmium, a metalloestrogen, and 9 other metals-arsenic, cobalt, chromium, copper, mercury, molybdenum, lead, tin, and vanadium--in relation to young-onset breast cancer (diagnosis age <50 years), which tends to be more aggressive than and have a different risk profile from later-onset disease. Recent metal exposure was measured by assessing element concentrations, via inductively coupled plasma mass spectrometry, in toenail clippings of 1,217 disease-discordant sister pairs in the US-based Sister (2003-2009) and Two Sister (2008-2010) studies. Conditional logistic regression was used to calculate odds ratios and 95% confidence intervals. After correcting for differential calendar time of sample collection, no statistically significant associations were observed between any metals and breast cancer. Vanadium had the largest odds ratio (for fourth vs. first quartile, odds ratio = 1.54, 95% confidence interval: 0.75, 3.16; P for trend = 0.21). The association between cadmium and young-onset breast cancer was near null, with no evidence of a dose-response relationship (for fourth vs. first quartile, odds ratio = 0.95, 95% confidence interval: 0.64, 1.43; P for trend = 0.64). Positive associations between urinary cadmium concentrations and breast cancer have been reported in case-control studies, but we observed no such association between young-onset breast cancer and toenail concentrations of any assessed metals.

A Cohort Study of Breast Cancer Risk after 20 Years of Follow-Up of Women Treated with Fertility Drugs

BACKGROUND

Using a nationwide cohort of Danish women, we investigated the association between use of fertility drugs and risk of breast cancer.

METHODS

The study cohort included women ages 20 to 44 years and living in Denmark between January 1, 1995 and December 31, 2011. Information on fertility status, use of fertility drugs, breast cancer, covariates, and vital status was obtained from the Danish Infertility Cohort and various Danish national registers. Cox proportional hazard regression models were applied to estimate hazard ratios (HR) and 95% confidence intervals (CI), adjusted for potential confounders.

RESULTS

Of the 1,330,852 women included, 96,782 (7.3%) were infertile, and 20,567 (1.5%) were diagnosed with breast cancer during a median follow-up of 20.9 years. Compared with fertile women, infertile women who had used any fertility drugs did not have an increased hazard for breast cancer overall (HR = 1.02; 95% CI, 0.95-1.10), or for any of the histologic types (ductal, lobular, or mucinous) of breast cancer. Furthermore, no associations were observed between use of specific types of fertility drugs and breast cancer.

CONCLUSIONS

No convincing associations between use of fertility drugs and breast cancer were observed after two decades of follow-up.

IMPACT

Our results do not support a marked association between fertility drugs and breast cancer and are therefore reassuring for infertile women treated with fertility drugs.

Ddx4+ Oogonial Stem Cells in Postmenopausal Women's Ovaries: A Controversial, Undefined Role

Recent studies support the existence of oogonial stem cells (OSCs) in the ovarian cortex of different mammals, including women.These cells are characterized by small size, membrane expression of DEAD(Asp-Glu-Ala-Asp)-box polypeptide-4 (Ddx4), and stemness properties (such as self-renewal and clonal expansion) as well as the ability to differentiate in vitro into oocyte-like cells. However, the discovery of OSCs contrasts with the popular theory that there is a numerically defined oocyte pool for female fertility which undergoes exhaustion with menopause. Indeed, in the ovarian cortex of postmenopausal women OSCs have been detected that possess both viability and capability to differentiate into oocytes, which is similar to those observed in younger patients. The pathophysiological role of this cell population in aged women is still debated since OSCs, under appropriate stimuli, differentiate into somatic cells, and the occurrence of Ddx4⁺ cells in ovarian tumor samples also suggests their potential involvement in carcinogenesis. Although further investigation into these observations is needed to clarify OSC function in ovary physiology, clinical investigators and researchers studying female infertility are presently focusing on OSCs as a novel opportunity to restore ovarian reserve in both young women undergoing early ovarian failure and cancer survivors experiencing iatrogenic menopause.

Toenail-Based Metal Concentrations and Young-Onset Breast Cancer

Several metals have carcinogenic properties, but their associations with breast cancer are not established. We studied cadmium, a metalloestrogen, and 9 other metals-arsenic, cobalt, chromium, copper, mercury, molybdenum, lead, tin, and vanadium--in relation to young-onset breast cancer (diagnosis age <50 years), which tends to be more aggressive than and have a different risk profile from later-onset disease. Recent metal exposure was measured by assessing element concentrations, via inductively coupled plasma mass spectrometry, in toenail clippings of 1,217 disease-discordant sister pairs in the US-based Sister (2003-2009) and Two Sister (2008-2010) studies. Conditional logistic regression was used to calculate odds ratios and 95% confidence intervals. After correcting for differential calendar time of sample collection, no statistically significant associations were observed between any metals and breast cancer. Vanadium had the largest odds ratio (for fourth vs. first quartile, odds ratio = 1.36, 95% confidence interval: 0.84, 2.21; P for trend = 0.17). Cadmium was associated with a small increase in risk, with no evidence of a dose-response relationship (for fourth vs. first quartile, odds ratio = 1.15, 95% confidence interval: 0.82, 1.60; P for trend = 0.67). Positive associations between urinary cadmium concentrations and breast cancer have been reported in case-control studies, but we observed no such association between young-onset breast cancer and toenail concentrations of any assessed metals.

Use of fertility medications and cancer risk: a review and update

PURPOSE OF REVIEW

There is increasing use of fertility medications for ovulation induction and ovarian stimulation for in-vitro fertilization in the treatment of female infertility. In this review, recent literature regarding the association between fertility medication and cancer risk is reviewed.

RECENT FINDINGS

Several important publications have recently addressed the relationship between use of fertility medications and cancer risk. There are methodological limitations to many of these studies, including unique challenges in studying rare cancers that often develop several years after the time of fertility medication exposure. Although infertility per se is a risk factor for some female cancers, including breast, endometrial and ovarian cancer, most studies do not show a significant risk of these cancers with the use of fertility medications. Some studies, however, have shown a possible increased relative risk of borderline ovarian cancer, although the increased absolute risk is small without a clear causal relationship.

SUMMARY

The collective data regarding the risk of developing cancer from use of fertility medications are reassuring, although several methodological issues in these studies limit definitive conclusions.

Ketamine and ketamine metabolites as novel estrogen receptor ligands: Induction of cytochrome P450 and AMPA glutamate receptor gene expression

Major depressive disorder (MDD) is the most common psychiatric illness worldwide, and it displays a striking sex-dependent difference in incidence, with two thirds of MDD patients being women. Ketamine treatment can produce rapid antidepressant effects in MDD patients, effects that are mediated-at least partially-through glutamatergic neurotransmission. Two active metabolites of ketamine, (2R,6R)-hydroxynorketamine (HNK) and (2S,6S)-HNK, also appear to play a key role in ketamine's rapid antidepressant effects through the activation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) glutamate receptors. In the present study, we demonstrated that estrogen plus ketamine or estrogen plus active ketamine metabolites displayed additive effects on the induction of the expression of AMPA receptor subunits. In parallel, the expression of estrogen receptor alpha (ERα) was also significantly upregulated. Even more striking, radioligand binding assays demonstrated that [³H]-ketamine can directly bind to ERα (K_D: 344.5 ± 13 nM). Furthermore, ketamine and its (2R,6R)-HNK and (2S,6S)-HNK metabolites displayed similar affinity for ERα (IC₅₀: 2.31 ± 0.1, 3.40 ± 0.2, and 3.53 ± 0.2 µM, respectively) as determined by [³H]-ketamine displacement assays. Finally, induction of AMPA receptors by either estrogens or ketamine and its metabolites was lost when ERα was knocked down or silenced pharmacologically. These results suggest a positive feedback loop by which estrogens can augment the effects of ketamine and its (2R,6R)-HNK and (2S,6S)-HNK metabolites on the ERα-induced transcription of CYP2A6 and CYP2B6, estrogen inducible enzymes that catalyze ketamine's biotransformation to form the two active metabolites. These observations provide novel insight into ketamine's molecular mechanism(s) of action and have potential implications for the treatment of MDD.

Safety of clomiphene citrate: a literature review

Clomiphene citrate (CC) is a nonsteroidal compound and induces ovulation indirectly. The wide usage of the CC raises a question; is it safe or not? In the light of this question, this review aimed to highlight all researches and insights into the association between the use of CC and risk of genotoxicity, cytotoxicity, embryotoxicity, teratogenicity and risk of different cancer types. We conducted a MEDLINE/PubMed, Scopus, Web of Science, Google Scholar search. After a careful screening process of all authors, 32 of these articles were considered as appropriate, and reviewed. Our evaluations showed that CC has genotoxic, cytotoxic, embryotoxic and teratogenic properties. There is no association between the use of CC and risk of ovarian, breast, uterine, cervix, endometrium, lung, colorectal cancer, and lymphoma. However, risk increased especially after 6 cycles of use and especially in nulligravid women. The use of CC should be restricted to 6 cycles. Moreover, malignant melanoma and thyroid cancer risk was found to be higher among CC treated women in almost all studies. Further works should be conducted especially in animal models to assess its risk features.

The Sister Study Cohort: Baseline Methods and Participant Characteristics

BACKGROUND

The Sister Study was designed to address gaps in the study of environment and breast cancer by taking advantage of more frequent breast cancer diagnoses among women with a sister history of breast cancer and the presumed enrichment of shared environmental and genetic exposures.

OBJECTIVE

The Sister Study sought a large cohort of women never diagnosed with breast cancer but who had a sister (full or half) diagnosed with breast cancer.

METHODS

A multifaceted national effort employed novel strategies to recruit a diverse cohort, and collected biological and environmental samples and extensive data on potential breast cancer risk factors.

RESULTS

The Sister Study enrolled 50,884 U.S. and Puerto Rican women 35-74y of age (median 56 y). Although the majority were non-Hispanic white, well educated, and economically well off, substantial numbers of harder-to-recruit women also enrolled (race/ethnicity other than non-Hispanic white: 16%; no college degree: 35%; household income <$50,000: 26%). Although all had a biologic sister with breast cancer, 16.5% had average or lower risk of breast cancer according to the Breast Cancer Risk Assessment Tool (Gail score). Most were postmenopausal (66%), parous with a first full-term pregnancy <30y of age (79%), never-smokers (56%) with body mass indexes (BMIs) of <29.9kg/m² (70%). Few (5%) reported any cancer prior to enrollment.

CONCLUSIONS

The Sister Study is a unique cohort designed to efficiently study environmental and genetic risk factors for breast cancer. Extensive exposure data over the life-course and baseline specimens provide important opportunities for studying breast cancer and other health outcomes in women. Collaborations are welcome. https://doi.org/10.1289/EHP1923.

[Does fertility treatment increase the risk of breast cancer? Current knowledge and meta-analysis]

OBJECTIVE

The objective of this review was to assess the level of risk of breast cancer for women exposed to ovulation-inducing therapy (OIT).

METHODS

The 25 selected studies were extracted from the PUBMED database from January 2000 until March 2016 with the following key-words: "fertility agents", "infertility treatments", "clomiphene citrate", "buserelin", "ovarian stimulation", "assisted reproductive technology" and "breast cancer". Our meta-analysis was performed using Review Manager software, Cochrane Collaboration, 2014. The results were calculated by type of OIT, as well as globally.

RESULTS

The analysis of these published epidemiological studies confirms that exposition to OIT is not a breast cancer risk factor, but the results are contradictory. Two studies have shown a significantly increased risk of breast cancer in a population of infertile women, while two others have found a significant decrease of this risk. The twenty others did not show any impact of IOT over this risk. Our meta-analysis of 20 selected studies has not identified a significant association between exposition to OIT and breast cancer risk (relative risk=0,96; IC 95: (0,81-1,14) for cohort studies and odds ratio=0,94; IC 95% (0,81-1,10) for case-control studies).

CONCLUSION

Exposition to OIT is not an identified risk factor for breast cancer. A message reassuring about a possible risk of OIT-related breast cancer should be given to these women. Exposition to OIT is therefore not an indication of increased breast surveillance.

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.

Assisted reproductive techniques after fertility-sparing treatments in gynaecological cancers

BACKGROUND

The trend toward late childbearing has made fertility preservation a major issue for women who face gynecological cancer. New techniques in assisted reproductive medicine enable conception after primary treatment of these cancers. Here, we aimed to review the efficacy and safety of assisted reproductive techniques (ART) after fertility-preserving treatment of gynaecological cancers.

METHODS

We conducted a systematic literature review of both prospective and retrospective studies in the PubMed, EMBASE, CENTRAL and SciSearch databases. In the retrieved studies, we evaluated live births, clinical pregnancies, overall survival and disease-free survival.

RESULTS

We identified many prospective and retrospective studies on this topic, but no relevant randomized clinical trials. Fertility-sparing treatments with safe oncological outcomes are feasible in endometrial, cervical and ovarian cancer cases. After cancer treatment, ART seem safe and show variable obstetrical outcomes.

CONCLUSIONS

After fertility-preserving treatment for gynaecological cancers, ART can enable pregnancy to be achieved with apparent oncological safety. The success of such procedures should directly impact clinical practice and management of those patients who require fertility-sparing treatment.

Use of clomiphene-based stimulation protocol in oocyte donors: A comparative study

INTRODUCTION:

This study was undertaken to compare between clomiphene citrate (CC) and gonadotropin-releasing hormone antagonist-based protocols in donor-recipient cycles in terms of parameters of ovarian stimulation and obstetric outcome.

MATERIALS AND METHODS:

Two hundred and three fertile oocyte donors were stimulated using two different protocols: Clomiphene based (n = 103) and antagonist based (n = 100). Donors in the one group were stimulated from day 1 or 2 of spontaneous or withdrawal bleeds with CC (50 mg/day) and recombinant follicle-stimulating hormone (FSH) till the day of trigger while donors in the other group were stimulated using recombinant FSH from day 1 or 2, and the antagonist was added as per flexible antagonist protocol. When >3 follicles were >17 mm in diameter, trigger was given with 2 mg leuprolide intramuscular. Transvaginal oocyte retrieval was done after 34 h of trigger.

RESULTS:

There was no significant difference in between the two groups in terms of age, antral follicle count, starting dose of gonadotropins, total dose required, duration of stimulation, number of follicles retrieved, mature follicles, and fertilization rate. The serum estradiol levels were significantly raised in the clomiphene group (P < 0.001). Pregnancy rate was similar in both the groups. The clinical pregnancy rate was 65.94% in the clomiphene group and 57.46% in the antagonist group. The live birth rate per cycle started was 47.8% in the clomiphene group and 39.55% in the antagonist group. There was one case of ectopic pregnancy in the antagonist group.

CONCLUSION:

Controlled ovarian stimulation using clomiphene and gonadotropin is a viable option for donor oocyte cycles. The cost and number of injections used per cycle can be reduced by using the clomiphene-based protocols.

Post-treatment Neurocognition and Psychosocial Care Among Breast Cancer Survivors

INTRODUCTION

Chemotherapy for breast cancer has been associated with cognitive problems; however, the impact of adjuvant hormone therapy is less clear. No studies have explored provider discussions about cognitive concerns or factors associated with neurocognitive treatment. This study examined cognitive problems, factors associated with having a provider discussion, and receipt of neurocognitive treatment.

METHODS

Female breast cancer survivors (N=2,537) from the Sister Study and the Two Sister Study who were at least 1 year post-treatment were surveyed in 2012 about their cancer therapies (confirmed by medical records); cognitive concerns; related provider discussions; and neurocognitive treatment. A total of 2,296 women were included in the current 2014 analysis. Extensive covariate information was also ascertained for predictive multivariate models.

RESULTS

The prevalence of self-reported cognitive problems after treatment was 60%. Of those reporting cognitive problems, only 37% had discussed those concerns with a provider and 15% had been treated for cognitive symptoms. The odds of reported cognitive concerns that started during and after treatment were elevated for those who received only hormone therapy and no chemotherapy (OR=1.64, 95% CI=1.15, 2.33); chemotherapy and no hormone therapy (OR=5.63, 95% CI=3.52, 9.00); or both (OR=6.33, 95% CI=4.21, 9.54) compared with those reporting neither treatment.

CONCLUSIONS

The high prevalence of cognitive concerns underscores the importance of monitoring breast cancer survivors for potential neurocognitive effects of hormone and chemotherapy, discussions with survivors about those concerns, and treatment referrals. Monitoring changes over time can help to evaluate both psychosocial and neurocognitive care provided for survivors.

Migraine and possible etiologic heterogeneity for hormone-receptor-negative breast cancer

Migraine headache is often timed with the menstrual cycle. Some studies have reported reduced risk of breast cancer in migraineurs but most of those did not distinguish menstrually-related from non-menstrually-related migraine. To examine the possible associations between breast cancer and migraine overall and between cancer subcategories and the two migraine subtypes, we used a cohort study of 50,884 women whose sister had breast cancer and a sister-matched case-control study including 1,418 young-onset (<50 years) breast cancer cases. We analyzed the two studies individually and also in tandem via a hybrid Cox model, examining subcategories of breast cancer in relation to menstrually-related and non-menstrually-related migraine. History of migraine was not associated with breast cancer overall. Migraine showed an inverse association with ductal carcinoma in situ (HR = 0.77; 95% CI (0.62,0.96)). Also, women with non-menstrually-related migraine had increased risk (HR = 1.30, 95% CI (0.93,1.81)) while women with menstrually-related migraine had decreased risk (HR = 0.63, 95% CI (0.42,0.96)) of hormone-receptor-negative (ER-/PR-) cancer, with a significant contrast in estimated effects (P = 0.005). While replication of these subset-based findings will be needed, effect specificity could suggest that while migraine has little overall association with breast cancer, menstrual migraine may be associated with reduced risk of ER-/PR- breast cancer.

Hormone therapy and young-onset breast cancer

Estrogen plus progestin hormone therapy (HT) is associated with an increased risk of postmenopausal breast cancer, but few studies have examined the impact of HT use on the risk of breast cancer in younger women. We assessed the association between estrogen plus progestin HT or unopposed estrogen HT and young-onset breast cancer using data from the Two Sister Study (2008-2010), a sister-matched study of 1,419 cases diagnosed with breast cancer before the age of 50 years and 1,665 controls. We assessed exposures up to a family-specific index age to ensure comparable opportunities for exposures and used propensity scores to control for birth cohort effects on HT use. Ever HT use was uncommon (7% and 11% in cases and controls, respectively). Use of estrogen plus progestin was not associated with an increased risk of young-onset breast cancer (odds ratio = 0.80, 95% confidence interval: 0.41, 1.59). Unopposed estrogen use was inversely associated with the risk of young-onset breast cancer (odds ratio = 0.58, 95% confidence interval: 0.34, 0.99). Duration of use, age at first use, and recency of use did not modify these associations.

Long-term relationship of ovulation-stimulating drugs to breast cancer risk

BACKGROUND

Although fertility drugs stimulate ovulation and raise estradiol levels, their effect on breast cancer risk remains unresolved.

METHODS

An extended follow-up was conducted among a cohort of 12,193 women evaluated for infertility between 1965 and 1988 at five U.S. sites. Follow-up through 2010 was achieved for 9,892 women (81.1% of the eligible population) via passive as well as active (questionnaires) means. Cox regression determined HRs and 95% confidence intervals (CI) for fertility treatments adjusted for breast cancer risk factors and causes of infertility.

RESULTS

During 30.0 median years of follow-up (285,332 person-years), 749 breast cancers were observed. Ever use of clomiphene citrate among 38.1% of patients was not associated with risk (HR = 1.05; 95% CI, 0.90-1.22 vs. never use). However, somewhat higher risks were seen for patients who received multiple cycles, with the risk for invasive cancers confirmed by medical records being significantly elevated (HR = 1.69; 95% CI, 1.17-2.46). This risk remained relatively unchanged after adjustment for causes of infertility and multiple breast cancer predictors. Gonadotropins, used by 9.6% of patients, mainly in conjunction with clomiphene, showed inconsistent associations with risk, although a significant relationship of use with invasive cancers was seen among women who remained nulligravid (HR = 1.98; 95% CI, 1.04-3.60).

CONCLUSIONS

Although the increased breast cancer risk among nulligravid women associated with gonadotropins most likely reflects an effect of underlying causes of infertility, reasons for the elevated risk associated with multiple clomiphene cycles are less clear.

IMPACT

Given our focus on a relatively young population, additional evaluation of long-term fertility drug effects on breast cancer is warranted.

Clinical use of fertility agents and risk of breast cancer: a recent update for an old problem

PURPOSE OF REVIEW

Female infertility is today a very common, expanding problem and therefore restoring fertility strategies are increasing in the last few years. An association between ovarian stimulation and breast cancer risk has been hypothesized, but the question has not yet been clarified.

RECENT FINDINGS

In the last 2 years, many important studies have been published on this topic. A lot of new combinations of drugs are in experimentation and other recent drugs are already in current use, such as aromatase inhibitors. Furthermore, the data from older studies were investigated by two recent meta-analyses.

SUMMARY

Infertility affects many couples in western countries and the use of fertility stimulation techniques is widespread in the last few years, determining personal anxiety, social costs, and organizing difficulties. It is well known that one of the most important causative agents for the development of breast cancer is the proliferative activity of endogenous and exogenous female hormones. Therefore, it seems appropriate to investigate the risk of breast cancer derived from the use of hormonal therapies in infertile women. The final clarification of this question is very important so that all women can realize their dream of having children, with the certainty of not being exposed to an increased risk of breast cancer.

[Breast and ovarian cancer due to BRCA1&2 hereditary cancer predisposition syndrome and reproduction: literature review]

INTRODUCTION

Germline mutations BRCA1&2 are responsible in women for breast and ovarian cancers that commonly occur at a young age: as such, there are strong interactions between the oncological risks and the events of reproductive life, pregnancy, breastfeeding, and management of infertility.

MATERIALS AND METHODS

A review of the international literature from the PubMed database was conducted, and recommendations of French health agencies were exposed. Published studies are case-control and cohort studies in the majority, with a low level of evidence.

RESULTS

Pregnancy and lactation have no effect on breast and ovaries or even decreases the risk. The sex ratio among patients carrying the mutation is in favor of girls. It is not observed more infertility in patients carrying a mutation despite a strong suspicion of premature ovarian failure, and infertility treatments do not increase breast and ovarian risk. There are ethical debates concerning the place of pre-natal diagnosis: both experts and concerned patients recommend a case-by-case analysis of the requests.

Breast cancer risk after exposure to fertility drugs

In recent years, there has been an increase in the diagnosis of infertility. In industrialized countries, approximately 15% of couples experience this problem today, with a negative impact on quality of life. For this reason, assisted reproductive technologies and other treatments, finalized to overcome infertility, have become very common in clinical practice. For a long time, different ovulation-inducing drugs have been used for ovarian follicle stimulation, either as independent therapies or treatments used during in vitro fertilization cycles. Despite this long-term use, the medical care for infertility gave rise to a lively debate about the potential risk of developing breast cancer that has never been settled. Many studies have been conducted to address this question; but their results have been, and still are, contradictory. The aim of this review is to determine the potential link between the use of fertility drugs and the risk of developing breast cancer in women treated for infertility.

IVF and breast cancer: a systematic review and meta-analysis

BACKGROUND

The effects of controlled ovarian hyperstimulation (COH) for IVF in terms of breast cancer risk remain controversial, despite the hormone-dependent nature of the latter.

METHODS

Eligible studies up to 15 February 2013 were identified and pooled effect estimates for relative risk (RR) were calculated separately for the investigations using the general population and those using infertile women, as a reference group. Fixed- or random-effects models were implemented and subgroup analyses were performed, as appropriate.

RESULTS

Eight cohort studies were synthesized, yielding a total cohort size of 1,554,332 women among whom 14,961 incident breast cancer cases occurred, encompassing 576 incident breast cancer cases among women exposed to IVF. No significant association between IVF and breast cancer was observed either in the group of studies treating the general population (RR = 0.91, 95% confidence interval (CI): 0.74-1.11) or infertile women (RR = 1.02, 95% CI: 0.88-1.18), as a reference group. Of note were the marginal associations, protective for pregnant and/or parous women after IVF (pooled effect estimate = 0.86, 95% CI: 0.73-1.01) and adverse for women <30 years at first IVF treatment (pooled effect estimate = 1.64, 95% CI: 0.96-2.80).

CONCLUSIONS

At present, COH for IVF does not seem to impart increased breast cancer risk. Longer follow-up periods, comparisons versus infertile women, subgroup analyses aiming to trace vulnerable subgroups, adjustment for various confounders and larger informative data sets are needed before conclusive statements for the safety of the procedure are reached.

Fertility preservation in breast cancer patients

Systemic therapies have been shown to effectively improve prognosis in patients with breast cancer. However, such therapies also become increasingly harmful as their duration increases, and they have adverse effects on fertility and ovarian function. Fertility preservation (FP) is important in young adult cancer survivors who may wish to have children. In Japan, some cancer societies recommend that the potentially serious effects of systemic therapy on ovarian function should be explained to women with cancer, and they should be encouraged to undergo FP prior to commencing treatment. Still, as there are no official guidelines, many oncologists lack the required knowledge and mind-set to advise young breast cancer patients on fertility issues. Counseling of patients and their families might improve their understanding about the influence of such treatment on fertility and ensure effective FP. There are several FP methods that can be selected before beginning treatment, and these methods have both advantages and disadvantages. Young adults with breast cancer who want to bear children in the future must be provided with FP counseling, in addition to advice about breast cancer treatment and prognosis.

Menopausal symptoms and the risk of young-onset breast cancer

BACKGROUND

Women with menopausal symptoms have been reported to have reduced risk of breast cancer, possibly reflecting differences in endogenous hormone levels. We examined the associations between menopausal symptoms and breast cancer in women under age 50.

METHODS

We carried out a sister-controlled case-control study, the Two Sister Study, comparing 1422 women with breast cancer diagnosed before age 50 and their 1669 sisters who were free of breast cancer and had enrolled in the prospective Sister Study cohort. History and age at first occurrence of menopause-associated symptoms (e.g. hot flashes, poor sleep or night sweats) were ascertained using computer-assisted telephone interviews. To equalise opportunity for exposure, we assessed exposures in relation to a sibship-based index age (the minimum of the age at diagnosis of the case sister and the age at interview of her control sister(s)), and estimated odds ratios using conditional logistic regression with adjustment for menopausal status and birth order.

FINDINGS

Having had menopause-associated symptoms (n=706) prior to the index age was associated with reduced risk of young-onset breast cancer (odds ratio (OR), 0.49; 95% confidence interval (CI), 0.40-0.61). Similar results were seen for hot flashes and for "other" menopausal symptoms. The association between menopausal symptoms and breast cancer risk was somewhat stronger for oestrogen receptor positive tumours than for oestrogen receptor negative tumours (heterogeneity p=0.07). Menopausal status, age at menopause, BMI and hormone replacement therapy did not modify the associations, but the inverse association between menopausal symptoms and breast cancer attenuated with increasing index age (p<0.01).

INTERPRETATION

Menopause-associated symptoms were associated with markedly reduced risk of young-onset breast cancer. Further studies are needed to confirm the association and elucidate possible pathways.