Effect of depo-medroxyprogesterone acetate on breast cancer risk among women 20 to 44 years of age

Depot medroxyprogesterone acetate and breast cancer: a systematic review

PURPOSE

Short-acting progestin-only injectables containing depot medroxyprogesterone acetate (DMPA) are a safe method of contraception. Although DMPA has been available for several decades, there is little data on its influence on the risk of breast cancer. Hence, the aim of this paper was to provide an overview of the existing studies and create clarity regarding a possible association with breast cancer.

METHODS

Literature searches were executed in MEDLINE, Embase, the Cochrane Library, ClinicalTrials.gov and ICTRP. Search terms were related to DMPA and breast cancer. After elimination of duplicates, 3'850 studies were identified and assessed according to inclusion and exclusion criteria. Finally, ten studies were selected and included in this review.

RESULTS

All the selected papers were case-control-studies, except for one pooled analysis and one study comparing observed and expected number of cancer cases. Most of the included studies found no overall elevated breast cancer incidence in DMPA users, only one study found a slightly increased risk and two studies concluded with a significant increase for the overall breast cancer risk.

CONCLUSION

There is little evidence that DMPA may increase the overall risk for breast cancer. However, the incidence of breast cancer is possibly increased in current and more recent users, especially in women younger than 35 years. Long-term use did not result in any risk increase. Nevertheless, further studies will be necessary to confirm these findings and weigh up the individual risks and benefits of this contraceptive method.

Progestins and breast cancer hallmarks: The role of the ERK1/2 and JNK pathways in estrogen receptor positive breast cancer cells

Progestins used in hormonal contraceptives and menopausal hormone therapy (MHT) have been linked to increased breast cancer risk. Whether the association holds for all progestins is unclear and the underlying mechanisms remain poorly understood. We directly compared the effects of four progestins (medroxyprogesterone acetate (MPA), norethisterone acetate (NET-A), levonorgestrel (LNG) and drospirenone (DRSP)) to each other and the natural progestogen progesterone (P4) on selected cancer hallmarks. To provide mechanistic insight into these effects, we assessed the role of the progesterone receptor (PR), and the extracellular signal-related kinase (ERK1/2) and c-Jun N terminal (JNK) signaling pathways. We showed that the increased proliferation of the luminal T47D breast cancer cell line by P4 and all progestins, albeit to different extents, was inhibited by PR knockdown and inhibition of both the ERK1/2 and JNK pathways. While knockdown of the PR also blocked the upregulation of MKI67 and CCND1 mRNA expression by selected progestogens, only a role for the ERK1/2 pathway could be established in these effects. Similarly, only a role for the ERK1/2 pathway could be confirmed for progestogen-induced colony formation, whereas both the ERK1/2 and JNK pathways were required for cell migration in response to the three older progestins implicated in the etiology of breast cancer, MPA, NET-A and LNG. Together our results show that all the progestins elicit their effects on cell proliferation via a mechanism requiring the PR, ERK1/2 and JNK pathways. While the ERK1/2 and JNK pathways are also required for increased cell migration by the older progestins, only a role for the ERK1/2 pathway could be established in their effects on colony formation. Notably, the cytoplasmic PR was not needed for activation of the ERK1/2 pathway by the progestogens. Given that DRSP showed significantly lower proliferation than MPA and NET-A, and that it had no effect on breast cancer cell migration and colony formation, hormonal formulations containing the newer generation progestin DRSP may provide a better benefit/risk profile towards breast cancer than those containing the older generation progestins.

Alcohol, Smoking, and Risks of Breast Cancer Recurrence and Mortality among Women with Luminal, Triple-Negative, and HER2-Overexpressing Breast Cancer

BACKGROUND

This study evaluates the relationship between smoking, alcohol, and breast cancer outcomes according to molecular subtype.

METHODS

This population-based prospective cohort consisted of 3,876 women ages 20 to 69 diagnosed with a first primary invasive breast cancer from 2004 to 2015 in the Seattle-Puget Sound region. Breast cancer was categorized into three subtypes based on estrogen receptor (ER), progesterone receptor (PR), and HER2 expressions: luminal (ER+), triple-negative (TN; ER-/PR-/HER2-), and HER2-overexpressing (H2E; ER-/HER2+). We fit Cox proportional hazards models to assess the association between alcohol consumption and smoking status at diagnosis and risks of recurrence, breast cancer-specific mortality, and all-cause mortality.

RESULTS

Histories of ever smoking [HR, 1.33; 95% confidence interval (CI), 1.01-1.74] and current smoking (HR, 1.59; 95% CI, 1.07-2.35) were associated with greater risk of breast cancer recurrence among TN cases. Smoking was also associated with greater risk of recurrence to bone among all cases and among luminal cases. Elevated risks of breast cancer-specific and all-cause mortality were observed among current smokers across all subtypes. Alcohol use was not positively associated with risk of recurrence or mortality overall; however, TN patients who drank four or more drinks per week had a decreased risk of recurrence (HR, 0.71; 95% CI, 0.51-0.98) and breast cancer-specific mortality (HR, 0.73; 95% CI, 0.55-0.97) compared with non-current drinkers.

CONCLUSIONS

Patients with breast cancer with a history of smoking at diagnosis have elevated risks of recurrence and mortality.

IMPACT

These findings underscore the need to prioritize smoking cessation among women diagnosed with breast cancer.

Progesterone receptor isoform ratios influence the transcriptional activity of progestins via the progesterone receptor

Progestins (synthetic progestogens) are progesterone receptor (PR) ligands used globally by women in both hormonal contraception and menopausal hormone therapy. Although four generations of unique progestins have been developed, studies seldom distinguish between the activities of progestins via the two functionally distinct PR isoforms, PR-A and PR-B. Moreover, not much is known about the action of progestins in breast cancer tumors where PR-A is mostly overexpressed relative to PR-B. Understanding progestin action in breast cancer is crucial since the clinical use of some progestins has been associated with an increased risk of developing breast cancer. This study directly compared the agonist activities of selected progestins from all four generations for transactivation and transrepression via either PR-A or PR-B, and when PR-A and PR-B were co-expressed at ratios comparable to those detected in breast cancer tumors. Comparative dose-response analysis showed that earlier generation progestins mostly displayed similar efficacies for transactivation on a minimal progesterone response element via the PR isoforms, while most of the 4th generation progestins, similar to the natural progestogen, progesterone (P4), were more efficacious via PR-B. Most of the progestogens were however more potent via PR-A. We are the first to show that the efficacies of the selected progestogens via the individual PR isoforms were generally decreased when PR-A and PR-B were co-expressed, irrespective of the ratio of PR-A:PR-B. While the potencies of most progestogens via PR-B were enhanced when the ratio of PR-A relative to PR-B was increased, those via PR-A were minimally influenced. This study is also the first to report that all progestogens evaluated, except 1st generation medroxyprogesterone acetate and 4th generation drospirenone, displayed similar agonist activity for transrepression via PR-A and PR-B on a minimal nuclear factor kappa B containing promoter. Moreover, we showed that the progestogen activity for transrepression was significantly increased when PR-A and PR-B were co-expressed. Taken together, our results highlight that PR agonists (progestogens) do not always display the same activity via PR-A and PR-B, or when PR-A and PR-B are co-expressed at ratios mimicking those found in breast cancer tumors. These results suggest that biological responses are progestogen- and PR isoform-dependent and may differ in target tissues expressing varying PR-A:PR-B ratios.

Combined and progestagen-only hormonal contraceptives and breast cancer risk: A UK nested case-control study and meta-analysis

BACKGROUND

Current or recent use of combined oral contraceptives (containing oestrogen+progestagen) has been associated with a small increase in breast cancer risk. Progestagen-only contraceptive use is increasing, but information on associated risks is limited. We aimed to assess breast cancer risk associated with current or recent use of different types of hormonal contraceptives in premenopausal women, with particular emphasis on progestagen-only preparations.

METHODS AND FINDINGS

Hormonal contraceptive prescriptions recorded prospectively in a UK primary care database (Clinical Practice Research Datalink [CPRD]) were compared in a nested case-control study for 9,498 women aged <50 years with incident invasive breast cancer diagnosed in 1996 to 2017, and for 18,171 closely matched controls. On average, 7.3 (standard deviation [SD] 4.6) years of clinical records were available for each case and their matched controls prior to the date of diagnosis. Conditional logistic regression yielded odds ratios (ORs) and 95% confidence intervals (CIs) of breast cancer by the hormonal contraceptive type last prescribed, controlled for age, GP practice, body mass index, number of recorded births, time since last birth, and alcohol intake. MEDLINE and Embase were searched for observational studies published between 01 January 1995 and 01 November 2022 that reported on the association between current or recent progestagen-only contraceptive use and breast cancer risk in premenopausal women. Fixed effects meta-analyses combined the CPRD results with previously published results from 12 observational studies for progestagen-only preparations. Overall, 44% (4,195/9,498) of women with breast cancer and 39% (7,092/18,171) of matched controls had a hormonal contraceptive prescription an average of 3.1 (SD 3.7) years before breast cancer diagnosis (or equivalent date for controls). About half the prescriptions were for progestagen-only preparations. Breast cancer ORs were similarly and significantly raised if the last hormonal contraceptive prescription was for oral combined, oral progestagen-only, injected progestagen, or progestagen-releasing intrauterine devices (IUDs): ORs = 1.23 (95% CI [1.14 to 1.32]; p < 0.001), 1.26 (95% CI [1.16 to 1.37]; p < 0.001), 1.25 (95% CI [1.07 to 1.45]; p = 0.004), and 1.32 (95% CI [1.17 to 1.49]; p < 0.001), respectively. Our meta-analyses yielded significantly raised relative risks (RRs) for current or recent use of progestagen-only contraceptives: oral = 1.29 (95% CI [1.21 to 1.37]; heterogeneity χ25 = 6.7; p = 0.2), injected = 1.18 (95% CI [1.07 to 1.30]; heterogeneity χ28 = 22.5; p = 0.004), implanted = 1.28 (95% CI [1.08 to 1.51]; heterogeneity χ23 = 7.3; p = 0.06), and IUDs = 1.21 (95% CI [1.14 to 1.28]; heterogeneity χ24 = 7.9; p = 0.1). When the CPRD results were combined with those from previous published findings (which included women from a wider age range), the resulting 15-year absolute excess risk associated with 5 years use of oral combined or progestagen-only contraceptives in high-income countries was estimated at: 8 per 100,000 users from age 16 to 20 years and 265 per 100,000 users from age 35 to 39 years. The main limitation of the study design was that, due to the nature of the CPRD data and most other prescription databases, information on contraceptive use was recorded during a defined period only, with information before entry into the database generally being unavailable. This means that although our findings provide evidence about the short-term associations between hormonal contraceptives and breast cancer risk, they do not provide information regarding longer-term associations, or the impact of total duration of contraceptive use on breast cancer risk.

CONCLUSIONS

This study provides important new evidence that current or recent use of progestagen-only contraceptives is associated with a slight increase in breast cancer risk, which does not appear to vary by mode of delivery, and is similar in magnitude to that associated with combined hormonal contraceptives. Given that the underlying risk of breast cancer increases with advancing age, the absolute excess risk associated with use of either type of oral contraceptive is estimated to be smaller in women who use it at younger rather than at older ages. Such risks need be balanced against the benefits of using contraceptives during the childbearing years.

Levonorgestrel-releasing intrauterine system-based therapies for early-stage endometrial cancer: a systematic review and meta-analysis

OBJECTIVE

To conduct a systematic review and meta-analysis of studies evaluating the oncological and fertility outcomes of early-stage endometrial cancer (EC) treated with the levonorgestrel-releasing intrauterine system (LIUS)-based regimens.

METHODS

The Meta-analyses Of Observational Studies in Epidemiology statement for meta-analyses was followed. Searches were conducted on MEDLINE, Embase, PubMed, Preprints, and the Cochrane Central Register of Controlled Trials from January 1990 to August 4, 2022. The Joanna Briggs Institute Critical Appraisal Checklist was used for quality assessment. The primary endpoint was the complete response (CR) rate and the secondary endpoints were relapse, pregnancy, and live birth rate.

RESULTS

A total of 25 studies (821 women) were included. The CR rate of LIUS-based regimens was 63.4% (95% confidence interval [CI]=52.3%-73.2%), with 29.6% (95% CI=23.3%-36.8%) of cases experiencing recurrence during follow-up. In sensitivity analyses, patients younger than 45 years of age with a body mass index <30 kg/m² who were treated with LIUS-based regimens achieved a high CR rate of 84.6% (95% CI=80.3%-88.1%) over a median follow-up of more than 24 months. Overall pregnancy and live birth rates were 37.9% (95% CI=24.1%-53.9%) and 39.3% (95% CI=24.0%-57.0%), respectively. No statistical differences were apparent in CR or relapse rates among the LIUS+GnRH agonist, LIUS+oral progesterone, or hysteroscopic resection followed by LIUS subgroups.

CONCLUSION

LIUS-based therapies are viable for the conservative management of early-stage endometrioid EC on CR and fertility outcome.

TRIAL REGISTRATION

PROSPERO Identifier: CRD42022352890.

Beyond the pill: contraception and the prevention of hereditary ovarian cancer

BRCA1 and BRCA2 mutation carriers face an elevated lifetime risk of developing ovarian cancer. Oral contraceptives have been shown to significantly decrease the risk of ovarian cancer by approximately 50% in this high-risk population. Changes in contraceptive formulations and patterns of use over time have introduced lower hormonal dosages, different steroid types and non-oral routes of administration. Specifically, there has been a considerable shift in patterns of contraceptive use and the increase in the uptake of non-oral, long-acting, reversible contraception (e.g., intrauterine devices, implants, injections) has corresponded to a decline in oral contraceptive pill use. Whether or not these other methods confer a protective effect against ovarian cancer in the general population is not clear. To our knowledge, there have been no such studies conducted among BRCA mutation carriers. Furthermore, the impact of these changes on the risk of developing ovarian cancer is not known. In this article, we will review the existing epidemiologic evidence regarding the role of contraceptives and the risk of ovarian cancer with a focus on women with a BRCA1 or BRCA2 mutation. We will discuss recent findings and gaps in the knowledge while extrapolating from studies conducted among women from the noncarrier population.

Differential off-target glucocorticoid activity of progestins used in endocrine therapy

The glucocorticoid receptor (GR) regulates transcription of genes involved in multiple processes. Medroxyprogesterone acetate (MPA), widely used in the injectable contraceptive Depo-MPA (DMPA), has off-target effects via the GR, which may result in side-effects in endocrine therapy. However, very little is known about the GR activity of other progestins used in endocrine therapy. This study compared GR activities for several progestins, using whole cell binding, dose-response, and GR phosphorylation assays, in both a cell line model and peripheral blood mononuclear cells (PBMCs). MPA, etonogestrel (ETG) and nestorone (NES) exhibit greater relative binding affinities for the GR than levonorgestrel (LNG) and norethisterone/norethindrone (NET) and are partial GR agonists for transactivation but agonists for transrepression on synthetic promoters in COS-1 cells. MPA is a potent agonist for endogenous GR-regulated GILZ and IL6 genes in PBMCs. While ETG and NES also display agonist activity on IL6, they have little effect on GILZ. In contrast, LNG and NET exhibit little to no activity in transactivation models, while both exhibit some transrepressive activity but are generally less potent and/or efficacious than MPA. Antagonist and phosphorylation assays confirmed that MPA and NES act via the GR on endogenous genes in PBMCs. Our results suggest GR-mediated dose-dependent and gene-specific transcriptional side-effects are likely to occur at physiologically relevant concentrations in vivo for MPA, may possibly occur selectively for ETG and NES, but are unlikely to occur for LNG and NET. This suggests that these progestins will exhibit differential side-effects in endocrine therapy via the GR.

Melatonin attenuates glucocorticoid effect induced by medroxyprogesterone acetate in rats

Medroxyprogesterone acetate (MPA) acts on glucocorticoid receptors and, when it is in excess, can cause clinical disorders comparable to hyperadrenocorticism. Melatonin (MEL) is a hormone with potent antioxidant and anti-glucocorticoid activity and it can be beneficial in the excessive activation of glucocorticoid receptors. To evaluate the protective effects of MEL on the glucocorticoid effect of MPA, 34 male Wistar rats were randomized into four groups: CON (control), MEL, MPA, and MPA + MEL. The animals were treated for 28 days, by subcutaneous injection. At the high dose that we used, the MPA caused effects compatible with an excessive activation of glucocorticoid receptors, resulting on a reduction in adrenal size, less weight gain, lower final body weight and feeding efficiency, and fewer lymphocytes compared with the control group. In addition, there was an increase in abdominal fat, cholesterol, very-low-density lipoprotein (VLDL), triglycerides, erythrocytes, hemoglobin, hematocrit, and hepatic vacuolization. We concluded that MEL was effective reducing the mean values of total cholesterol, high-density lipoprotein (HDL), urea, VLDL, triglycerides, hepatic microvacuolization and abdominal fat/weight in rats treated with MPA. These findings indicate that MEL attenuates the harmful effects of MPA.

Linking Physical Activity to Breast Cancer: Text Mining Results and a Protocol for Systematically Reviewing Three Potential Mechanistic Pathways

Epidemiologic research suggests that physical activity is associated with a reduced risk of breast cancer, but the causal nature of this link is not clear. Investigating mechanistic pathways can provide evidence of biological plausibility and improve causal inference. This project will examine three putative pathways (sex steroid hormones, insulin signaling, and inflammation) in a series of two-stage systematic reviews. Stage 1 used Text Mining for Mechanism Prioritisation (TeMMPo) to identify and prioritize relevant biological intermediates. Stage 2 will systematically review the findings from studies of (i) physical activity and intermediates and (ii) intermediates and breast cancer. Ovid MEDLINE, EMBASE, and SPORTDiscus will be searched using a combination of subject headings and free-text terms. Human intervention and prospective, observational studies will be eligible for inclusion. Meta-analysis will be performed where possible. Risk of bias will be assessed using the Cochrane Collaboration tool, or the ROBINS-I or ROBINS-E tool, depending on study type. Strength of evidence will be assessed using the GRADE system. In addition to synthesizing the mechanistic evidence that links physical activity with breast cancer risk, this project may also identify priority areas for future research and help inform the design and implementation of physical activity interventions.See related reviews by Swain et al., p. 16 and Drummond et al., p. 28.

Steroid Receptors in Breast Cancer: Understanding of Molecular Function as a Basis for Effective Therapy Development

Breast cancer remains one of the most important health problems worldwide. The family of steroid receptors (SRs), which comprise estrogen (ER), progesterone (PR), androgen (AR), glucocorticoid (GR) and mineralocorticoid (MR) receptors, along with a receptor for a secosteroid-vitamin D, play a crucial role in the pathogenesis of the disease. They function predominantly as nuclear receptors to regulate gene expression, however, their full spectrum of action reaches far beyond this basic mechanism. SRs are involved in a vast variety of interactions with other proteins, including extensive crosstalk with each other. How they affect the biology of a breast cell depends on such factors as post-translational modifications, expression of coregulators, or which SR isoform is predominantly synthesized in a given cellular context. Although ER has been successfully utilized as a breast cancer therapy target for years, research on therapeutic application of other SRs is still ongoing. Designing effective hormone therapies requires thorough understanding of the molecular function of the SRs. Over the past decades, huge amount of data was obtained in multiple studies exploring this field, therefore in this review we attempt to summarize the current knowledge in a comprehensive way.

Mechanisms of endocrine therapy resistance in breast cancer

The most commonly diagnosed breast cancer (BC) subtype is characterized by estrogen receptor (ER) expression. Treatment of this BC subtype typically involves modalities that either suppress the production of estrogen or impede the binding of estrgen to its receptors, constituting the basis for endocrine therapy. While many patients have benefitted from endocrine therapy with clear reduction in mortality and cancer recurrence, one of the clinical hurdles that remain involves overcoming intrinsic (de novo) or acquired resistance to endocrine therapy driven by diverse and complex changes occurring in the tumor microenvironment. Moreover, such resistance may persist even after progression through additional antiestrogen therapies thus demonstrating the importance of further investigation of mechanisms of ER modulation. Here, we discuss a number of advances that provide a better understanding of the complex mechanistic basis for resistance to endocrine therapy as well as future therapeutic maneuvers that may break this resistance.

The Impact of Progestin-only Contraception on Adolescents with Macromastia

Progestin-only contraception has become increasingly popular among adolescents. However, patients, parents, and providers share concerns regarding the potential impact that progestin-only contraception may have on breast growth. We sought to explore the impact of progestin-only contraception on breast hypertrophy and symptomatology in adolescents with macromastia.

Progesterone Receptor Signaling in the Breast Tumor Microenvironment

The tumor microenvironment (TME) is a complex infrastructure composed of stromal, epithelial, and immune cells embedded in a vasculature ECM. The microenvironment surrounding mammary epithelium plays a critical role during the development and differentiation of the mammary gland, enabling the coordination of the complex multihormones and growth factor signaling processes. Progesterone/progesterone receptor paracrine signaling interactions in the microenvironment play vital roles in stem/progenitor cell function during normal breast development. In breast cancer, the female sex hormones, estrogen and progesterone, and growth factor signals are altered in the TME. Progesterone signaling modulates not only breast tumors but also the breast TME, leading to the activation of a series of cross-communications that are implicated in the genesis of breast cancers. This chapter reviews the evidence that progesterone and PR signaling modulates not only breast epitheliums but also the breast TME. Furthermore, crosstalk between estrogen and progesterone signaling affecting different cell types within the TME is discussed. A better understanding of how PR and progesterone affect the TME of breast cancer may lead to novel drugs or a therapeutic approach for the treatment of breast cancer shortly.

Breast Cancer Risk with Progestin Subdermal Implants: A Challenge in Patients Counseling

There is a steady global rise in the use of progestin subdermal implants, where use has increased by more than 20 times in the past two decades. BC risk has been reported with the older progestin only methods such as oral pills, injectables, and intrauterine devices, however, little is known about the risk with subdermal implants. In this review, we aim to update clinicians and researchers on the current evidence to support patient counseling and to inform future research directions. The available evidence of the association between the use of progestin subdermal implants and BC risk is discussed. We provide an overview of the potential role of endogenous progesterone in BC development. The chemical structure and molecular targets of synthetic progestins of relevance are summarized together with the preclinical and clinical evidence on their association with BC risk. We review all studies that investigated the action of the specific progestins included in subdermal implants. As well, we discuss the potential effect of the use of subdermal implants in women at increased BC risk, including carriers of BC susceptibility genetic mutations.

Modern menstruation: Is it abnormal and unhealthy?

The menstrual cycle appears to have evolved in humans and some other species to improve reproductive efficiency by enabling progesterone production without the presence of the fetus. This phenomenon is termed spontaneous decidualization. Repeated menstruation is produced in modern women because of better general health and having fewer pregnancies later in life and limiting breast feeding. The repeated breakdown of a progesterone primed endometrium releases an inflammatory cascade which appears to have short and long term adverse consequences. Repetitive modern menstruation is no longer a sign of good general and reproductive health but a harbinger of possible future health problems. Cyclical menstruation has no intrinsic biological value or necessity in modern life. Spontaneous decidualization can be prevented by using estrogen-progestin combinations or progestins on their own. Newer and safer hormonal products are now available and should become even safer in the future. Hormonal suppression of spontaneous decidualization should be encouraged in adolescent and young women as a health promotional option.

Executive Summary of the Early-Onset Breast Cancer Evidence Review Conference

The Centers for Disease Control and Prevention launched the Bring Your Brave campaign to increase knowledge about early-onset breast cancer, defined as breast cancer in women aged 18-45 years. The American College of Obstetricians and Gynecologists convened a panel of experts in breast disease from the Society for Academic Specialists in General Obstetrics and Gynecology to review relevant literature, validated tools, best practices, and practice guidelines as a first step toward developing educational materials for women's health care providers about early-onset breast cancer. Panel members conducted structured literature reviews, which were then reviewed by other panel members and discussed at an in-person meeting of stakeholder professional and patient advocacy organizations in April 2019. This article summarizes the relevant literature, existing guidance, and validated tools to guide health care providers in the prevention, early detection, and special considerations of early-onset breast cancer. Substantive knowledge gaps were noted and summarized to provide guidance for future research.

Molecular mechanisms underlying progesterone receptor action in breast cancer: Insights into cell proliferation and stem cell regulation

The ovarian steroid hormone progesterone and its nuclear receptor, the Progesterone Receptor (PR), play an essential role in the regulation of cell proliferation and differentiation in the mammary gland. In addition, experimental and clinical evidence demonstrate their critical role in controlling mammary gland tumorigenesis and breast cancer development. When bound to its ligand, the main action of PR is as a transcription factor, which regulates the expression of target genes networks. PR also activates signal transduction pathways through a rapid or non-genomic mechanism in breast cancer cells, an event that is fully integrated with its genomic effects. This review summarizes the molecular mechanisms of the ligand-activated PR actions that drive epithelial cell proliferation and the regulation of the stem cell population in the normal breast and in breast cancer.

Association of hormone replacement therapy with increased risk of meningioma in women: A hospital-based multicenter study with propensity score matching

AIM

There is no consensus regarding the association between hormone replacement therapy (HRT) and risk of meningioma so far. We conducted the first study among Chinese female patients to investigate the influence of HRT use on the risk of meningioma.

METHODS

We retrospectively collected records of diagnosis of meningioma for women aged 50 years and above during 2011-2016 and dispense of HRT prior to meningioma diagnosis in three tertiary hospitals in China. Meningioma cases were matched with controls at a ratio of 1:2 by using nearest neighbor propensity scores matching in order to balance the baseline characteristics between groups, which generated a total of 629 cases with 1258 controls.

RESULTS

We observed prior use of HRT associated with increased risk of meningioma (odds ratio [OR], 1.2; 95% confidence interval [CI], 1.0-1.4) and the association was more prominent among women having multiple HRT dispenses and longer term exposure (OR, 1.3; 95% CI, 1.1-1.6), among those with combination therapy of estrogens and progestogens (OR, 1.3; 95% CI, 1.1-1.7) than monotherapy, and among progestogen users than estrogen users as for monotherapy. Furthermore, vaginal, subcutaneous implant seems to be associated with a higher risk of meningioma compared with oral administration although no significance had been reached.

CONCLUSION

This case-control study provides evidence that hormone use for an HRT purpose might constitute the development and growth of meningioma as an independent risk factor, especially for combination therapy and/or long-term users, which supports that meningioma might be a hormone-sensitive tumor.

Association of Combined Estrogen-Progestogen and Progestogen-Only Contraceptives with the Development of Cancer

Combined estrogen-progestogen contraceptives (oral contraceptives or OCs) and progestogen-only contraceptives (POCs) are synthetic steroids that bind to steroid hormone receptors, which are widespread throughout the body. They have a profound effect on cellular physiology. Combined OCs have been classified by the International Agency for Research on Cancer (IARC) as Group 1 carcinogens, but their findings have not been updated recently. In order to update the information and better understand the impact that OCs and POCs have on the risk of development of cancers, a comprehensive literature search was undertaken, focusing on more recently published papers. In agreement with the IARC, the recent literature confirms an increased risk of breast cancer and cervical cancer with the use of OCs. The recent literature also confirms the IARC conclusion that OCs decrease the risk of ovarian and endometrial cancers. However, there is little support from recent studies for the IARC conclusion that OCs decrease the risk of colorectal cancer or increase the risk of liver cancer. For liver cancer, this may be due to the recent studies having been performed in areas where hepatitis is endemic. In one large observational study, POCs also appear to increase the overall risk of developing cancer. OCs and POCs appear to increase the overall risk of cancer when carefully performed studies with the least intrinsic bias are considered.

Summary

OCs have been classified as cancer-causing agents, especially leading to increases in breast cancer and cervical cancer. A review of the recent scientific literature was performed to see whether this still appears to be the case. The recent literature supports the cancer-causing role of OCs especially for breast cancer and cervical cancer. Studies also indicate that progesterone-only contraceptives (such as implants and vaginal rings) also can cause cancer. This is especially true for breast cancer and cervical cancer.

Alcohol, smoking, and risk of Her2-overexpressing and triple-negative breast cancer relative to estrogen receptor-positive breast cancer

Epidemiological evidence is limited on how alcohol consumption and smoking are associated with risk of different subtypes of breast cancer, such as triple-negative (TN) and human epidermal growth factor receptor 2-overexpressing (H2E) breast cancers, which may have different etiologies from more common luminal (estrogen receptor [ER+]) breast cancers. In this population-based case-case study, we evaluated the association between alcohol, smoking, and risk of H2E and TN breast cancer, compared with ER+ breast cancers, among women aged 20-69 years. Using polytomous regression, associations between alcohol consumption, smoking, and breast cancer risk were evaluated in 909 ER+, 1,290 TN, and 489 H2E breast cancer patients, with ER+ breast cancer patients as the reference group. Current alcohol consumption at diagnosis was associated with a lower risk of H2E breast cancer (odds ratio = 0.74, 95% confidence interval: 0.58-0.92) relative to ER+ cancers. No difference in association was observed by menopausal status. No association between alcohol consumption and TN breast cancer relative to ER+ breast cancer was observed. Women who smoked did not have an altered risk of TN or H2E breast cancer, relative to ER+ cancer. Our results suggest that alcohol is associated with lower risk of H2E breast cancer relative to ER+ breast cancer. This study adds to the body of epidemiologic evidence that breast cancer etiology differs by breast cancer subtype.

Estrogen and progesterone signalling in the normal breast and its implications for cancer development

The ovarian hormones estrogen and progesterone are master regulators of the development and function of a broad spectrum of human tissues, including the breast, reproductive and cardiovascular systems, brain and bone. Acting through the nuclear estrogen (ER) and progesterone receptors (PR), both play complex and essential coordinated roles in the extensive development of the lobular alveolar epithelial structures of the normal breast during puberty, the normal menstrual cycle and pregnancy. The past decade has seen major advances in understanding the mechanisms of action of estrogen and progesterone in the normal breast and in the delineation of the complex hierarchy of cell types regulated by ovarian hormones in this tissue. There is evidence for a role for both ER and PR in driving breast cancer, and both are favourable prognostic markers with respect to outcome. In this review, we summarize current knowledge of the mechanisms of action of ER and PR in the normal breast, and implications for the development and management of breast cancer.

Revisiting progesterone receptor (PR) actions in breast cancer: Insights into PR repressive functions

Progesterone receptor (PR) is a master regulator in female reproductive tissues that controls developmental processes and proliferation and differentiation during the reproductive cycle and pregnancy. PR also plays a role in progression of endocrine-dependent breast cancer. As a member of the nuclear receptor family of ligand-dependent transcription factors, the main action of PR is to regulate networks of target gene expression in response to binding its cognate steroid hormone, progesterone. Liganded-PR transcriptional activation has been thoroughly studied and associated mechanisms have been described while progesterone-mediated repression has remained less explored. The present work summarizes recent advances in the understanding of how PR-mediated repression is accomplished in breast cancer cells and highlights the significance of fully understanding the determinants of context-dependent PR action.

Hormonal contraceptives and breast cancer: Clinical data

The endocrine background of breast cancer has raised questions about the increase in risk that might bear the use of hormonal contraceptives. This has been a particular issue in the case of young women, who constitute the population of contraceptive consumers. Observational studies have been the main source of evidence, which has mainly limited to the combined estrogen-progestogen preparations, the popular pill. Studies in the 80's and 90's of the past century found a small, around a 20%, increase in risk. The translation in absolute number of excess cases has been exiguous because the prevalence of the disease is relatively small in premenopausal women. Moreover, the risk slowly seemed to disappear after 5-10 years of use. The more sophisticated analyses provided by new technologies, together with the powerful central registries in some countries, has confirmed increased risk of similar size. Recent preparations, with lower doses of estrogens and new progestogenic molecules, have not substantially modified the risk size. The impact of progestogen only alternatives, either pills or progestogen-loaded intrauterine devices, seems to be similar, but the evidence is still insufficient. Whether there is a preferential effect on histological or molecular subtypes of breast tumours is being debated yet. The data on women at higher risk, either with mutations of the BRCA1/2 genes or with familial weight, have not found specific response patterns, but the experience is still meagre. It is of interest that long-term follow up data on women who enrolled in the initial cohorts, like that of the Royal College of General Practitioners', have shown a considerable protection against cancer of the ovary (relative risk, RR 0.67), endometrium (RR 0.66), or colorectum (RR 0.81).

Breast Cancer Epidemiology, Prevention, and Screening

Globally, breast cancer is both the most commonly occurring cancer and the commonest cause of cancer death among women. Available data suggest that incidence and mortality in high-resource countries has been declining whereas incidence and mortality in low-resource countries has been increasing. This pattern is likely to be due to changing risk factor profiles and differences in access to breast cancer early detection and treatment. Risk factors for breast cancer include increasing age, race, menarche history, breast characteristics, reproductive patterns, hormone use, alcohol use, tobacco use, diet, physical activity, and body habitus. Mutations in the BRCA 1 and BRCA 2 tumor suppressor genes are significantly associated with the development of breast and ovarian cancer by the age of 70. Survival depends on both stage and molecular subtype. As there are few signs and symptoms early on, early detection is an important strategy to improve outcomes. Major professional organizations in the United States and elsewhere recommend screening with mammography with appropriate follow up for an abnormal screening test, although they differ somewhat by recommended ages and frequency of screening. Studies suggest a 15%-40% mortality reduction secondary to screening, however, there are also concerns about harms, such as overdiagnosis (5%-54%) and overtreatment leading to long term complications, and false negatives (6%-46%). Identification of women at risk for BRCA1 and BRCA 2 mutations is also recommended with referral for genetic testing. Preventive interventions, such as lifestyle, medical, and surgical options are available for women testing positive for BRCA mutations.

Hormonal contraception and breast cancer, what more do we need to know?

Most women use hormonal contraception for more than 30 years and for many, this may involve exposure in their older reproductive years when baseline breast cancer risk rises steeply. Overall, the risk of breast cancer diagnosis with exposure to hormonal contraception is very small and outweighed by its contraceptive benefits but despite this, there are still outstanding questions for all methods used in clinical practice due to paucity of available evidence, lack of which should not be taken to imply safety. This is exemplified by the following assumptions: the progestogen-only pill and long-acting reversible contraceptives are 'breast-safe' options in peri-menopausal women, use of the levonorgestrel intrauterine system for the management of endometrial pathology in breast cancer survivors is less likely to promote disease recurrence and the benefit all hormonal contraceptive methods confer in reducing unplanned pregnancy in women at high familial risk outweigh the risk of breast cancer diagnosis. There is no data on risk with the concurrent prescription of hormone replacement therapy in women exhibiting climacteric symptoms who are still menstruating. Advice of GPs and Community Sexual & Reproductive Health specialists will inevitably be sought about some or all these issues and in the absence of conclusive evidence from clinical studies, caution should be applied and women counselled appropriately.

Progestins used in endocrine therapy and the implications for the biosynthesis and metabolism of endogenous steroid hormones

Steroidogenesis refers to the de novo synthesis of steroid hormones from cholesterol by a number of sequential enzyme catalysed reactions in the adrenal and the gonads. In addition, circulating steroid hormone precursors are further metabolised in selected peripheral tissues. It has been suggested that the biosynthesis of endogenous steroid hormones can be modulated by progestins, used widely by women in female reproductive medicine. However, as a number of structurally diverse progestins with different pharmacological properties are available, it is possible that these synthetic compounds may vary in their effects on steroidogenesis. This review summarises the evidence indicating that progestins influence the biosynthesis of steroid hormones in the adrenal and gonads, as well as the metabolism of these endogenous hormones in the breast, highlighting the limitations to the current knowledge and directions for future research.

A Way Forward for Cancer Chemoprevention: Think Local

As cells progress through carcinogenesis, the associated exponential expansion of genetic and molecular aberrations and resultant heterogeneity make therapeutic success increasingly unattainable. Therapeutic intervention at early stages of carcinogenesis that occurs within the primary organ and in the face of a lower burden of molecular aberrations, constitutes a basic tenet of cancer chemoprevention, and provides a situation that favors a greater degree of therapeutic efficacy compared with that of advanced cancer. A longstanding barrier to chemoprevention relates to the requirement for essentially no systemic toxicity, and the fact that when large numbers of people are treated, the emergence of systemic toxicity is almost universal. A rational means to address this in fact relates to a second basic tenet of the chemopreventive strategy: the focus of therapeutic intervention is to disrupt a process that is in essence localized to a single organ. Based upon this consideration, a strategy which is based upon local delivery of therapeutics to an at-risk organ will achieve therapeutic efficacy while avoiding systemic delivery and its associated toxicity. This article will review the rationale for undertaking such an approach, describe successful clinical achievements based on this strategy, describe ongoing efforts to expand the impact of this approach, and together will highlight the high impact that this approach has already had on the field as well as its extremely high potential for future impact. Cancer Prev Res; 10(1); 14-35. ©2016 AACR.

Depo-Provera (depot medroxyprogesterone acetate) use after bariatric surgery

In the US, obesity rates are increasing greatly. The Centers for Disease Control and Prevention estimates that 68.5% of Americans, including 63.9% of adult women older than 20 years, are overweight (body mass index between 25 kg/m² and 29.9 kg/m²) or obese (body mass index >30 kg/m²). In light of this, it is not surprising that the rates of bariatric surgery have also been increasing. When considering the metabolic changes associated with both bariatric surgery and contraceptive use, in combination with the unique medical considerations of obese women, it is indisputable that clear guidelines are needed when counseling obese patients of reproductive age after bariatric surgery. In this literature review, we focus on depot medroxyprogesterone acetate (DMPA) and the implications of its use in obese women, preweight and postweight loss following bariatric surgery. Both DMPA use and bariatric surgery are known to cause bone loss, but it is still unclear whether there is an additive effect of the two factors on bone loss and whether either of these factors directly leads to an increased risk of bone fracture. The current consensus guidelines do not impose a restriction on the use of DMPA after bariatric surgery. DMPA use is associated with weight gain, and it is unclear whether weight loss blunting occurs with the use of DMPA after bariatric surgery. Prior studies had demonstrated an association with weight gain in adolescents, and therefore, those prescribing DMPA use after bariatric surgery in adolescents should proceed with caution. Adult women do not have a similar response to the use of DMPA. DMPA use has rarely been associated with increased risk of venous thromboembolism (VTE). The obesity-associated increase in VTE should be mitigated by surgically induced weight loss. The concurrent use of DMPA in the post bariatric surgical period should not further increase the risk of VTE.

Reproductive Factors and Risk of Luminal, HER2-Overexpressing, and Triple-Negative Breast Cancer Among Multiethnic Women

BACKGROUND

Reproductive factors are among the most well-established risk factors for breast cancer. However, their associations with different breast cancer subtypes defined by joint estrogen receptor (ER)/progesterone receptor (PR)/HER2 status remain unclear.

METHODS

We assessed relationships between reproductive factors and risks of luminal A (ER(+)/HER2(-)), luminal B (ER(+)/HER2(+)), triple-negative (TN; ER(-)/PR(-)/HER2(-)), and HER2-overexpressing (H2E; ER(-)/HER2(+)) breast cancers in a population-based case-case study consisting of 2,710 women ages 20-69 years diagnosed between 2004 and 2012. ORs and 95% confidence intervals (CI) were estimated with luminal A cases serving as the reference group using polytomous logistic regression.

RESULTS

Earlier age at first full-term pregnancy and age at menopause were positively associated with odds of TN breast cancer (Ptrend: 0.003 and 0.024, respectively). Parity was associated with a 43% (95% CI, 1.08-1.89) elevated odds of H2E breast cancer, and women who had ≥3 full-term pregnancies had a 63% (95% CI, 1.16-2.29, Ptrend = 0.013) increased odds of this subtype compared with nulliparous women. Breast feeding for ≥36 months was associated with a 49% (OR 0.51; 95% CI, 0.27-0.99) lower odds of TN breast cancer.

CONCLUSION

Our results suggest that reproductive factors contribute differently to risks of the major molecular subtypes of breast cancer.

IMPACT

African American and Hispanic women have higher incidence rates of the more aggressive TN and H2E breast cancers and their younger average age at first pregnancy, higher parity, and less frequent breast feeding could in part contribute to this disparity. Cancer Epidemiol Biomarkers Prev; 25(9); 1297-304. ©2016 AACR.

Body mass index and risk of luminal, HER2-overexpressing, and triple negative breast cancer

Triple negative (TN, tumors that do not express estrogen receptor (ER), progesterone receptor (PR), or human epidermal growth factor receptor 2 (HER2)) and HER2-overexpressing (H2E, ER-/HER2+) tumors are two particularly aggressive subtypes of breast cancer. There is a lack of knowledge regarding the etiologies of these cancers and in particular how anthropometric factors are related to risk. We conducted a population-based case-case study consisting of 2659 women aged 20-69 years diagnosed with invasive breast cancer from 2004 to 2012. Four case groups defined based on joint ER/PR/HER2 status were included: TN, H2E, luminal A (ER+/HER2-), and luminal B (ER+/HER2+). Polytomous logistic regression was used to estimate odds ratios (ORs) and associated 95 % confidence intervals (CIs) where luminal A patients served as the reference group. Obese premenopausal women [body mass index (BMI) ≥30 kg/m(2)] had an 82 % (95 % CI 1.32-2.51) increased risk of TN breast cancer compared to women whose BMI <25 kg/m(2), and those in the highest weight quartile (quartiles were categorized based on the distribution among luminal A patients) had a 79 % (95 % CI 1.23-2.64) increased risk of TN disease compared to those in the lowest quartile. Among postmenopausal women obesity was associated with reduced risks of both TN (OR = 0.74, 95 % CI 0.54-1.00) and H2E (OR = 0.47, 95 % CI 0.32-0.69) cancers. Our results suggest obesity has divergent impacts on risk of aggressive subtypes of breast cancer in premenopausal versus postmenopausal women, which may contribute to the higher incidence rates of TN cancers observed among younger African American and Hispanic women.

Progesterone receptor antagonism inhibits progestogen-related carcinogenesis and suppresses tumor cell proliferation

PURPOSE

Blockade of the progestogen-progesterone receptor (PR) axis is a novel but untested strategy for breast cancer prevention. We report preclinical data evaluating telapristone acetate (TPA), ulipristal acetate (UPA), and mifepristone.

METHODS

Tumors were induced with medroxyprogesterone acetate (MPA) plus 7,12-dimethylbenz[a]anthracene (DMBA) in mice, and MPA or progesterone plus N-methyl-N-nitrosourea (MNU) in rats. Mammary gland histology, tumor incidence, latency, multiplicity, burden and histology were evaluated, along with immunohistochemical labeling of pHH3 (proliferation), CD34 (angiogenesis), and estrogen and progesterone receptors (ER and PR). A concentration gradient of TPA, UPA, and mifepristone was tested for growth inhibition of T47D spheroids.

RESULTS

In mouse mammary glands, no tumors formed, but TPA opposed the pro-hyperplastic effects of MPA (p = 0.002). In rats, TPA decreased tumor incidence (p = 0.037 for MPA + TPA vs. MPA, and p = 0.032 for progesterone + TPA vs. progesterone) and tumor burden (p = 0.042 for progesterone + TPA vs. progesterone), with significant decreases in pHH3 and CD34 positive cells. TPA and UPA were superior to mifepristone in growth inhibition of T47D spheroids.

CONCLUSION

TPA has consistent anti-tumorigenic effects in several models, which are accompanied by decreases in cell proliferation, angiogenesis, and hormone receptor expression.

Inverse Relationship between Progesterone Receptor and Myc in Endometrial Cancer

Endometrial cancer, the most common gynecologic malignancy, is a hormonally-regulated disease. Response to progestin therapy positively correlates with hormone receptor expression, in particular progesterone receptor (PR). However, many advanced tumors lose PR expression. We recently reported that the efficacy of progestin therapy can be significantly enhanced by combining progestin with epigenetic modulators, which we term “molecularly enhanced progestin therapy.” What remained unclear was the mechanism of action and if estrogen receptor α (ERα), the principle inducer of PR, is necessary to restore functional expression of PR via molecularly enhanced progestin therapy. Therefore, we modeled advanced endometrial tumors that have lost both ERα and PR expression by generating ERα-null endometrial cancer cell lines. CRISPR-Cas9 technology was used to delete ERα at the genomic level. Our data demonstrate that treatment with a histone deacetylase inhibitor (HDACi) was sufficient to restore functional PR expression, even in cells devoid of ERα. Our studies also revealed that HDACi treatment results in marked downregulation of the oncogene Myc. We established that PR is a negative transcriptional regulator of Myc in endometrial cancer in the presence or absence of ERα, which is in contrast to studies in breast cancer cells. First, estrogen stimulation augmented PR expression and decreased Myc in endometrial cancer cell lines. Second, progesterone increased PR activity yet blunted Myc mRNA and protein expression. Finally, overexpression of PR by adenoviral transduction in ERα-null endometrial cancer cells significantly decreased expression of Myc and Myc-regulated genes. Analysis of the Cancer Genome Atlas (TCGA) database of endometrial tumors identified an inverse correlation between PR and Myc mRNA levels, with a corresponding inverse correlation between PR and Myc downstream transcriptional targets SRD5A1, CDK2 and CCNB1. Together, these data reveal a previously unanticipated inverse relationship between the tumor suppressor PR and the oncogene Myc in endometrial cancer.

Relationship between prolactin, breast cancer risk, and antipsychotics in patients with schizophrenia: a critical review

OBJECTIVE

A recent meta-analysis showed that breast cancer probably is more common in female patients with schizophrenia than in the general population (effect size = 1.25, P < 0.05). Increasing experimental and epidemiological data have alerted researchers to the influence of prolactin (PRL) in mammary carcinogenesis. We therefore investigated the possible relationship between antipsychotic-induced hyperprolactinemia (HPRL) and breast cancer risk in female patients with schizophrenia.

METHOD

A literature search (1950 until January 2015), using the MEDLINE database, was conducted for English-language published clinical trials to identify and synthesize data of the current state of knowledge concerning breast cancer risk (factors) in women with schizophrenia and its (their) relationship between HPRL and antipsychotic medication.

RESULTS

Although an increasing body of evidence supports the involvement of PRL in breast carcinogenesis, results of human prospective studies are limited, equivocal, and correlative (with risk ratios ranging from 0.70 to 1.9 for premenopausal women and from 0.76 to 2.03 for postmenopausal women). Moreover, these studies equally do not take into account the local production of PRL in breast epithelium, although amplification or overexpression of the local autocrine/paracrine PRL loop may be a more important mechanism in tumorigenesis. Until now, there is also no conclusive evidence that antipsychotic medication can increase the risk of breast malignancy and mortality.

CONCLUSION

Other breast risk factors than PRL, such as nulliparity, obesity, diabetes mellitus, and unhealthy lifestyle behaviours (alcohol dependence, smoking, low physical activity), probably are of greater relevance in individual breast cancer cases within the population of female patients with schizophrenia.

Screening for Chemical Contributions to Breast Cancer Risk: A Case Study for Chemical Safety Evaluation

BACKGROUND

Current approaches to chemical screening, prioritization, and assessment are being reenvisioned, driven by innovations in chemical safety testing, new chemical regulations, and demand for information on human and environmental impacts of chemicals. To conceptualize these changes through the lens of a prevalent disease, the Breast Cancer and Chemicals Policy project convened an interdisciplinary expert panel to investigate methods for identifying chemicals that may increase breast cancer risk.

METHODS

Based on a review of current evidence, the panel identified key biological processes whose perturbation may alter breast cancer risk. We identified corresponding assays to develop the Hazard Identification Approach for Breast Carcinogens (HIA-BC), a method for detecting chemicals that may raise breast cancer risk. Finally, we conducted a literature-based pilot test of the HIA-BC.

RESULTS

The HIA-BC identifies assays capable of detecting alterations to biological processes relevant to breast cancer, including cellular and molecular events, tissue changes, and factors that alter susceptibility. In the pilot test of the HIA-BC, chemicals associated with breast cancer all demonstrated genotoxic or endocrine activity, but not necessarily both. Significant data gaps persist.

CONCLUSIONS

This approach could inform the development of toxicity testing that targets mechanisms relevant to breast cancer, providing a basis for identifying safer chemicals. The study identified important end points not currently evaluated by federal testing programs, including altered mammary gland development, Her2 activation, progesterone receptor activity, prolactin effects, and aspects of estrogen receptor β activity. This approach could be extended to identify the biological processes and screening methods relevant for other common diseases.

Active FOXO1 Is a Key Determinant of Isoform-Specific Progesterone Receptor Transactivation and Senescence Programming

Progesterone promotes differentiation coupled to proliferation and prosurvival in the breast, but inhibits estrogen-driven growth in the reproductive tract and ovaries. Herein, it is demonstrated, using progesterone receptor (PR) isoform-specific ovarian cancer model systems, that PR-A and PR-B promote distinct gene expression profiles that differ from PR-driven genes in breast cancer cells. In ovarian cancer models, PR-A primarily regulates genes independently of progestin, while PR-B is the dominant ligand-dependent isoform. Notably, FOXO1 and the PR/FOXO1 target gene p21 (CDKN1A) are repressed by PR-A, but induced by PR-B. In the presence of progestin, PR-B, but not PR-A, robustly induced cellular senescence via FOXO1-dependent induction of p21 and p15 (CDKN2B). Chromatin immunoprecipitation (ChIP) assays performed on PR isoform-specific cells demonstrated that while each isoform is recruited to the same PRE-containing region of the p21 promoter in response to progestin, only PR-B elicits active chromatin marks. Overexpression of constitutively active FOXO1 in PR-A-expressing cells conferred robust ligand-dependent upregulation of the PR-B target genes GZMA, IGFBP1, and p21, and induced cellular senescence. In the presence of endogenous active FOXO1, PR-A was phosphorylated on Ser294 and transactivated PR-B at PR-B target genes; these events were blocked by the FOXO1 inhibitor (AS1842856). PR isoform-specific regulation of the FOXO1/p21 axis recapitulated in human primary ovarian tumor explants treated with progestin; loss of progestin sensitivity correlated with high AKT activity.

IMPLICATIONS

This study indicates FOXO1 as a critical component for progesterone signaling to promote cellular senescence and reveals a novel mechanism for transcription factor control of hormone sensitivity.

Progesterone action in breast, uterine, and ovarian cancers

Progesterone and progesterone receptors (PRs) are essential for the development and cyclical regulation of hormone-responsive tissues including the breast and reproductive tract. Altered functions of PR isoforms contribute to the pathogenesis of tumors that arise in these tissues. In the breast, progesterone acts in concert with estrogen to promote proliferative and pro-survival gene programs. In sharp contrast, progesterone inhibits estrogen-driven growth in the uterus and protects the ovary from neoplastic transformation. Progesterone-dependent actions and associated biology in diverse tissues and tumors are mediated by two PR isoforms, PR-A and PR-B. These isoforms are subject to altered transcriptional activity or expression levels, differential crosstalk with growth factor signaling pathways, and distinct post-translational modifications and cofactor-binding partners. Herein, we summarize and discuss the recent literature focused on progesterone and PR isoform-specific actions in breast, uterine, and ovarian cancers. Understanding the complexity of context-dependent PR actions in these tissues is critical to developing new models that will allow us to advance our knowledge base with the goal of revealing novel and efficacious therapeutic regimens for these hormone-responsive diseases.

Progestin-only contraception: injectables and implants

Progestin-only contraceptive injectables and implants are highly effective, longer-acting contraceptive methods that can be used by most women in most circumstances. Globally, 6% of women using modern contraception use injectables and 1% use implants. Injectables are the predominant contraceptive method used in sub-Saharan Africa, and account for 43% of modern contraceptive methods used. A lower-dose, subcutaneous formulation of the most widely used injectable, depot-medroxyprogesterone acetate, has been developed. Implants have the highest effectiveness of any contraceptive method. Commodity cost, which historically limited implant availability in low-resource countries, was markedly lowered between 2012 and 2013. Changes in menstrual bleeding patterns are extremely common with both methods, and a main cause of discontinuation. Advice from normative bodies differs on progestin-only contraceptive use by breastfeeding women 0-6 weeks postpartum. Whether these methods are associated with HIV acquisition is a controversial issue, with important implications for sub-Saharan Africa, which has a disproportionate burden of both human immunodeficiency virus (HIV) and maternal mortality.

Height, body mass index (BMI), BMI change, and the risk of estrogen receptor-positive, HER2-positive, and triple-negative breast cancer among women ages 20 to 44 years

BACKGROUND

The evidence regarding correlations between various anthropometric characteristics and breast cancer risk among young women is mixed, and few studies have assessed these associations by subtype.

METHODS

This was a population-based, case-control study of 779 women with estrogen receptor (ER)-positive breast cancer; 182 women with ER-negative/human epidermal growth factor-2 (HER2)-negative/progesterone receptor-negative (triple-negative [TN]) breast cancer; and 60 women with ER-negative/HER2-overexpressing, invasive breast cancer ages 20 to 44 years who were diagnosed from 2004 to 2010 in the Seattle-Puget Sound metropolitan area; as well as 939 cancer-free controls. Associations between height and body mass index (BMI) at different time points in relation to breast cancer risk were assessed using polytomous logistic regression.

RESULTS

Height, BMI at age 18 years, and BMI at the reference date were not related to the risks of ER-positive, TN, or HER2-overexpressing breast cancer. Changes in BMI from age 18 years to the reference date were not related to the risk of either ER-positive or HER2-overexpressing breast cancer. However, compared with women who had a BMI change from 0 to 4.9 kg/m(2) from age 18 years to the reference date, those who experienced a BMI increase ≥10 kg/m(2) during the same interval had a 2.0-fold (95% confidence interval, 1.2-fold to 3.3-fold increase) increased risk of TN breast cancer. For women with ER-positive disease, there was some evidence that parity modified the effect of BMI change (Pinteraction  = .002), because a BMI increase of ≥10 kg/m(2) was associated with a reduced risk of ER-positive disease only among nulliparous women (odds ratio, 0.3; 95% confidence interval, 0.2-0.6).

CONCLUSIONS

The correlations appear to differ substantially between BMI change and the risks of TN breast cancer and ER-positive breast cancer.

Tracking progesterone receptor-mediated actions in breast cancer

Ovarian steroid hormones contribute to breast cancer initiation and progression primarily through the actions of their nuclear transcription factors, the estrogen receptor alpha (ERα) and progesterone receptors (PRs). These receptors are important drivers of the luminal A and B subtypes of breast cancer, where estrogen-blocking drugs have been effective endocrine therapies for patients with these tumors. However, many patients do not respond, or become resistant to treatment. When endocrine therapies fail, the luminal subtypes of breast cancer are more difficult to treat because these subtypes are among the most heterogeneous in terms of mutation diversity and gene expression profiles. Recent evidence suggests that progestin and PR actions may be important drivers of luminal breast cancers. Clinical trial data has demonstrated that hormone replacement therapy with progestins drives invasive breast cancer and results in greater mortality. PR transcriptional activity is dependent upon cross-talk with growth factor signaling pathways that alter PR phosphorylation, acetylation, or SUMOylation as mechanisms for regulating PR target gene selection required for increased cell proliferation and survival. Site-specific PR phosphorylation is the primary driver of gene-selective PR transcriptional activity. However, PR phosphorylation and heightened transcriptional activity is coupled to rapid PR protein degradation; the range of active PR detected in tumors is likely to be dynamic. Thus, PR target gene signatures may provide a more accurate means of tracking PR's contribution to tumor progression rather than standard clinical protein-based (IHC) assays. Further development of antiprogestin therapies should be considered alongside antiestrogens and aromatase inhibitors.

Active smoking and the risk of estrogen receptor-positive and triple-negative breast cancer among women ages 20 to 44 years

BACKGROUND

Evidence regarding the correlation between smoking and breast cancer among young women is mixed, and previous studies have not assessed whether smoking is associated differentially with risks of the major breast cancer subtypes.

METHODS

This was a population-based, case-control study of 778 women with estrogen receptor (ER)-positive breast cancers and 182 women with ER-negative, progesterone receptor-negative, and human epidermal growth factor receptor 2-negative (triple-negative [TN]), invasive breast cancers ages 20 to 44 years who were diagnosed from 2004 to 2010 in the Seattle-Puget Sound metropolitan area. A control group of 938 cancer-free women also was included. Associations between various aspects of smoking history and the risks of ER-positive and TN breast cancer were assessed using polytomous logistic regression.

RESULTS

Ever-smokers had a 1.3-fold increased risk (95% confidence interval [CI], 1.1-fold to 1.7-fold increased risk) of breast cancer overall; and, when stratified by cancer subtype, they had a 1.4-fold increased risk (95% CI, 1.1-fold to 1.8-fold increased risk) of ER-positive breast cancer, but there was no elevation in their risk of TN disease (odds ratio, 1.1; 95% CI, 0.7-1.6). Current/recent smokers with a ≥10 pack-year history of smoking had a 1.6-fold increased risk (95% CI, 1.1-fold to 2.4-fold increased risk) of ER-positive breast cancer but had no increase in their risk of TN breast cancer (odds ratio, 1.0; 95% CI, 0.5-1.9).

CONCLUSIONS

The current results suggested that young women who are current/recent smokers with high pack-year histories may have an increased risk of ER-positive breast cancer but not TN breast cancer. Although this association was modest, the findings suggest that an increased risk of ER-positive breast cancer may be another health risk incurred by young women who smoke.

Oral contraceptives and breast cancer risk overall and by molecular subtype among young women

BACKGROUND

Evidence suggests that recent oral contraceptive (OC) use is associated with a small increased breast cancer risk; yet risks associated with contemporary OC preparations and by molecular subtype are not well characterized.

METHODS

We conducted a population-based case-control study of invasive breast cancer among women ages 20 to 44 residing in the Seattle-Puget Sound area from 2004 to 2010 (985 cases and 882 controls). We collected information on contraceptive use and participant characteristics via an in-person interview. Multivariable-adjusted logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

Lifetime duration of OC use for ≥ 15 years was associated with an increased breast cancer risk (OR, 1.5; 95% CI, 1.1-2.2). Current OC use (within 1 year of reference date) for ≥ 5 years was associated with an increased risk (OR, 1.6; 95% CI, 1.1-2.5) and there were no statistically significant differences in risk by OC preparation. Risk magnitudes were generally greater among women ages 20 to 39, and for estrogen receptor-negative (ER(-)) and triple-negative breast cancer (current use for ≥ 5 years among ages 20-39: ER(-) OR, 3.5; 95% CI, 1.3-9.0; triple-negative OR, 3.7; 95% CI, 1.2-11.8), although differences between groups were not statistically significant.

CONCLUSIONS

Long-term use of contemporary OCs and current use for ≥ 5 years was associated with an increased breast cancer risk among women ages 20 to 44. Risk may be greater among younger women and for ER(-) and triple-negative breast cancer, but these findings require confirmation.

IMPACT

Continued surveillance and pooled analyses of OC use and breast cancer risk by molecular subtype are needed as OC preparations evolve.

Gestodene: a review of its pharmacology, potency and tolerability in combined contraceptive preparations

Combined progestin-estrogen pills are an established and reliable contraceptive option used by women worldwide. Combined oral contraceptives (COCs) containing the progestins--gestodene, desogestrel or norgestimate--were developed to minimize androgenic side effects and are considered an effective, well-tolerated contraceptive option. Gestodene achieves contraceptive efficacy with the lowest dose of any progestin in a COC, and has an established and favorable short- and long-term tolerability profile. In this review we present an overview of the pharmacology, potency and tolerability of gestodene.

Menstrual suppression in the adolescent

Menstrual suppression, the use of contraceptive methods to eliminate or decrease the frequency of menses, is often prescribed for adolescents to treat menstrual disorders or to accommodate patient preference. For young women using hormonal contraceptives, there is no medical indication for menstruation to occur monthly, and various hormonal contraceptives can be used to decrease the frequency of menstruation with different side effect profiles and rates of amenorrhea. This article reviews the different modalities for menstrual suppression, common conditions in adolescents which may improve with menstrual suppression, and strategies for managing common side effects.