The role of estrogen deprivation therapy in premenopausal women with primary unresectable intracardiac leiomyomatosis: a systematic review and meta-analysis

Background Intracardiac leiomyomatosis (ICLM) is a rare life-threatening form of intravenous leiomyomatosis (IVLM). The incomplete resection and recurrence are associated with high morbidity and mortality. The objective of this study is to identify that whether estrogen deprivation therapies, including bilateral salpingo-oophorectomy (BSO)-based surgery and gonadotrophin releasing hormone agonists (GnRHa) administration, could bring benefits to patients with primary unresectable ICLM. Methods PubMed/MEDLINE (Ovid) was searched (up to May 2021) for studies reporting individual patient data on demographics, clinicopathological features, treatment, and follow-up information. Exclusion criteria were patients who may have been included in two or more publications. This study was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Results A total of 114 patients from 70 papers were included. Several reports showed that the tumor in the right atrium and inferior vena cava shrank dramatically after BSO-based surgery, or GnRHa administrated preoperatively in premenopausal women. The rate of complete resection was 64.04% in patients with ICLM, which was 85.25% in no/slight adhesion and no pulmonary nodules group, while 22.22% in firm/extensive adhesion and/or pulmonary nodules group (p < 0.0001). Meanwhile, the recurrence rates in patients with complete resection and incomplete resection were 4.29% and 37.84% respectively (p < 0.0001). Furthermore, complete resection with BSO had the lowest recurrence rate of 3.13%, incomplete resection with BSO had a progression rate of 45.45%, while incomplete resection with ovarian preservation had the highest progression rate of 75.00%. Conclusions The recurrence rate of ICLM was closely related to firm/extensive adhesion in IVC or above, and/or pulmonary nodules. BSO-based surgery might reduce the recurrence rate no matter ICLM could be completely resected or not. In addition, estrogen deprivation therapies could decrease tumor burden as a primary treatment, and further make a secondary complete resection feasible in premenopausal women with initially unresectable ICLM.

Aromatase Inhibitor-Associated Musculoskeletal Syndrome: Understanding Mechanisms and Management

Aromatase inhibitors (AIs) are a key component in the chemoprevention and treatment of hormone receptor-positive (HR+) breast cancer. While the addition of AI therapy has improved cancer-related outcomes in the management of HR+ breast cancer, AIs are associated with musculoskeletal adverse effects known as the aromatase inhibitor-associated musculoskeletal syndrome (AIMSS) that limit its tolerability and use. AIMSS is mainly comprised of AI-associated bone loss and arthralgias that affect up to half of women on AI therapy and detrimentally impact patient quality of life and treatment adherence. The pathophysiology of AIMSS is not fully understood though has been proposed to be related to estrogen deprivation within the musculoskeletal and nervous systems. This review aims to characterize the prevalence, risk factors, and clinical features of AIMSS, and explore the syndrome’s underlying mechanisms and management strategies.

Sex steroids receptors, hypertension, and vascular ageing

Sex hormone receptors are expressed throughout the vasculature and play an important role in the modulation of blood pressure in health and disease. The functions of these receptors may be important in the understanding of sexual dimorphism observed in the pathophysiology of both hypertension and vascular ageing. The interconnectivity of these factors can be exemplified in postmenopausal females, who with age and estrogen deprivation, surpass males with regard to hypertension prevalence, despite experiencing significantly less disease burden in their estrogen replete youth. Estrogen and androgen receptors mediate their actions via direct genomic effects or rapid non-genomic signaling, involving a host of mediators. The expression and subtype composition of these receptors changes through the lifespan in response to age, disease and hormonal exposure. These factors may promote sex steroid receptor-mediated alterations to the Renin–Angiotensin–Aldosterone System (RAAS), and increases in oxidative stress and inflammation, thereby contributing to the development of hypertension and vascular injury with age.

Neratinib plus trastuzumab is superior to pertuzumab plus trastuzumab in HER2-positive breast cancer xenograft models

Lapatinib (L) plus trastuzumab (T), with endocrine therapy for estrogen receptor (ER)+ tumors, but without chemotherapy, yielded meaningful response in HER2+ breast cancer (BC) neoadjuvant trials. The irreversible/pan-HER inhibitor neratinib (N) has proven more potent than L. However, the efficacy of N+T in comparison to pertuzumab (P) + T or L + T (without chemotherapy) remains less studied. To address this, mice bearing HER2+ BT474-AZ (ER+) cell and BCM-3963 patient-derived BC xenografts were randomized to vehicle, N, T, P, N+T, or P+T, with simultaneous estrogen deprivation for BT474-AZ. Time to tumor regression/progression and incidence/time to complete response (CR) were determined. Changes in key HER pathway and proliferative markers were assessed by immunohistochemistry and western blot of short-term-treated tumors. In the BT474-AZ model, while all N, P, T, N + T, and P + T treated tumors regressed, N + T-treated tumors regressed faster than P, T, and P + T. Further, N + T was superior to N and T alone in accelerating CR. In the BCM-3963 model, which was refractory to T, P, and P + T, while N and N + T yielded 100% CR, N + T accelerated the CR compared to N. Ki67, phosphorylated (p) AKT, pS6, and pERK levels were largely inhibited by N and N + T, but not by T, P, or P + T. Phosphorylated HER receptor levels were also markedly inhibited by N and N + T, but not by P + T or L + T. Our findings establish the efficacy of combining N with T and support clinical testing to investigate the efficacy of N + T with or without chemotherapy in the neoadjuvant setting for HER2+ BC.

Breast Cancer Endocrine Therapy Exhausts Adipocyte Progenitors Promoting Weight Gain and Glucose Intolerance

Breast cancer survivors treated with anti-estrogen therapies report weight gain and have an elevated risk of type 2 diabetes. Here, we show that current tamoxifen use did not influence body mass index but associated with larger breast adipocyte diameter only in women with obesity, suggesting adipose tissue may be targeted by breast cancer therapies. To understand the mechanisms behind these clinical findings, we investigated the impact of estrogen deprivation and tamoxifen in a relevant pre-clinical murine model of obesity. Specifically, mature female mice were housed at thermoneutrality and fed either a low-fat/low-sucrose (LFLS) or a high-fat/high-sucrose (HFHS) diet. Consistent with the high expression of Esr1 observed in single-cell RNA sequencing of mesenchymal stem cells from mouse adipose tissue, endocrine therapies associated with adipose accumulation and preadipocyte expansion, but resulted in adipocyte progenitor depletion only in the context of HFHS. Consequently, 7-week endocrine therapy supported adipocyte hypertrophy and was associated with hepatic steatosis, hyperinsulinemia, insulin resistance, and glucose intolerance, particularly in HFHS fed females. We administered HFHS fed females either metformin or pioglitazone, glucose lowering drugs used to treat diabetes, or treadmill interval exercise during endocrine therapy with the goal of improving whole body metabolism. All interventions prevented the effects of tamoxifen but not estrogen deprivation on adipocyte size and insulin resistance in HFHS-fed mice. This translational study suggests that endocrine therapies may act via ER-alpha to directly disrupt adipocyte progenitors and support adipocyte hypertrophy, leading to ectopic lipid deposition that may promote hyperinsulinemia, insulin resistance and type 2 diabetes. Interventions that target insulin action should be considered for some women receiving life-saving endocrine therapies for breast cancer.

Hormonal Regulation of Semaphorin 7a Promotes Therapeutic Resistance in Breast Cancer

Background: The majority of all breast cancers (BC) are estrogen receptor positive (ER+). While ER-targeting endocrine therapies have improved patient survival, many of these tumors develop drug resistance and recur within 20 years. Therefore, novel targets are needed to predict for recurrence and to treat recurrent ER+BC. Previous reports describe a tumor-promotional role for Semaphorin 7A (SEMA7A) in ER- disease; yet, the role of SEMA7A in ER+ disease is poorly characterized. Hypothesis: SEMA7A promotes cell survival and drug resistance in ER+ BC. Methods: We overexpressed SEMA7A in ER+ BC cells, then used the ER-targeting agents tamoxifen and fulvestrant to test how SEMA7A-expressing cells respond to endocrine therapy. In vitro, we used proliferation and cell survival assays. In vivo, we implanted ER+ BC cells, then treated the animals with fulvestrant to measure how SEMA7A affects tumor growth and metastasis. We also utilized drug resistant cells, which have high endogenous SEMA7A levels, to measure markers of stemness and multi-drug resistance via flow cytometry. Results: We first found that SEMA7A expression correlates with decreased relapse free survival in patients with ER+BC who received endocrine therapy (Kmplotter; p=0.042). We also observe that SEMA7A is hormonally regulated in ER+BC, but its expression does not uniformly decrease with endocrine therapy agents. Instead, long term estrogen deprivation and ER-targeting drug treatments increase SEMA7A expression, likely through the action of other hormone receptors such as the androgen receptor, which also increases with long term estrogen deprivation. Further, in ER+ cell lines, overexpression of SEMA7A promotes in vitro growth in the face of estrogen-deprivation, tamoxifen, or fulvestrant treatments. In vivo, SEMA7A promotes fulvestrant resistance in the primary tumor and induces lung metastases. Finally, we report that pro-survival signaling is a therapeutic vulnerability of ER+SEMA7A+ tumors. Conclusion: These studies describe that SEMA7A promotes drug resistance in ER+ BC. We propose that targeting pro-survival signaling may prove efficacious for treating SEMA7A+ tumors, which are less likely to respond to endocrine therapies.

785 Estrogen-deprivation promotes Th1 polarization of tumor-associated T cells in a mouse model of high grade serous ovarian cancer

BackgroundImmunotherapy has achieved long-term survival in patients with melanoma and other tumors, introducing a new paradigm in cancer treatment. Differential outcomes among men and women receiving immune checkpoint inhibitors implicate sex steroids as modulators of treatment response. Estrogen signaling has a profound impact on T cell function and has been shown to upregulate FoxP3 expression, promoting a suppressive regulatory phenotype. Conversely, estrogen deprivation promotes Th1 skewing, including increased IFN-γ production in response to antigen-specific stimulation. We hypothesize that immunomodulatory effects of estrogen deprivation will enhance immunotherapy outcomes.Our lab has previously demonstrated that IFN-γ levels in the TME predict response to immune checkpoint blockade (ICB) regimens in ovarian cancer models. CTLA4 but not PD1/PDL1 ICB combined with PARP inhibition (PARPi), an oral chemotherapeutic, significantly increased IFN-γ in the TME. Furthermore, IFN-γ was required for the durable survival benefit achieved with PARPi/anti-CTLA4. Here we test whether estrogen deprivation enhances IFN-γ production in the TME and response to PARPi/anti-PD1.MethodsFive-week-old female FVB mice underwent oophorectomy, laparotomy without oophorectomy (sham), or no surgery (n = 5 per group). On day 10, mice were intraperitoneally challenged with 200,000 BR5-Akt syngeneic OC cells and randomly assigned to receive either PARPi/anti-CTLA4, PARPi/anti-PD1 or vehicle control treatment. PARPi (40mg/kg/day) was administered days 13-30 and 100 μg of anti-CTLA4 or 300 μg anti-PD1 was administered on D14. A second dose of anti-PD1 was given on D24. On day 30, peritoneal cells were analyzed by flow cytometry. Tumor burden was measured by IVIS.ResultsOophorectomy was associated with a significant increase in IFN-γ production by tumor-associated CD4+ T cells [30.4% vs 8.2%, p = 0.016] and an increase in the proportion of central memory CD8+ T cells [59.3% vs 34.9%, p = 0.007] in response to PARPi/anti-PD1 compared with sham and no-surgery controls. In contrast, no differences in T cell phenotype or function was noted among groups receiving PARPi/anti-CTLA4. These changes were associated with a decrease in tumor burden in response to PARPi/anti-PD1 on D30.ConclusionsEstrogen deprivation promotes Th1 polarization among tumor-associated T cells in response to PARPi/anti-PD1 treatment. With evidence that high levels of IFN-γ in the TME strongly correlate with survival, we predict that these effects will enhance treatment outcomes in response to PARPi/anti-PD1. This work presents a rationale for testing estrogen receptor modulators in combination with immune therapy agents and provides a potential mechanism to account for observed differences in patient outcomes.