Effect of tamoxifen on fibrosis,collagen content and transforming growth factor‐β1, ‐β2 and ‐β3 expression in common bile duct anastomosis of pigs

End‐to‐end anastomosis in the treatment for bile duct injury during laparoscopic cholecystectomy has been associated with stricture formation. The aim of this study was to experimentally investigate the effect of oral tamoxifen (tmx) treatment on fibrosis, collagen content and transforming growth factor‐β1, ‐β2 and ‐β3 expression in common bile duct anastomosis of pigs. Twenty‐six pigs were divided into three groups [sham (n = 8), control (n = 9) and tmx (n = 9)]. The common bile ducts were transected and anastomosed in the control and tmx groups. Tmx (40 mg/day) was administered orally to the tmx group, and the animals were euthanized after 60 days. Fibrosis was analysed by Masson's trichrome staining. Picrosirius red was used to quantify the total collagen content and collagen type I/III ratio. mRNA expression of transforming growth factor (TGF)‐β1, ‐β2 and ‐β3 was quantified using real‐time polymerase chain reaction (qRT‐PCR). The control and study groups exhibited higher fibrosis than the sham group, and the study group showed lower fibrosis than the control group (P = 0.011). The control and tmx groups had higher total collagen content than the sham group (P = 0.003). The collagen type I/III ratio was higher in the control group than in the sham and tmx groups (P = 0.015). There were no significant differences in the mRNA expression of TGF‐β1, ‐β2 and ‐β3 among the groups (P > 0.05). Tmx decreased fibrosis and prevented the change in collagen type I/III ratio caused by the procedure.     

Fulvestrant for the treatment of endometrial cancer

Introduction: About one third of patients with endometrial cancer (EC) relapse and face a limited prognosis, if surgery or radiotherapy are not feasible. The remaining therapeutic options are chemotherapy and endocrine therapy.

Areas covered: This review summarizes the development of the first selective estrogen receptor (ER) down-regulator fulvestrant. This article provides its mechanism of action, pharmacokinetics and the available preclinical and clinical data. Furthermore, this review provides an overview of the market of treatments for recurrent or metastatic EC (RMEC) while also taking into account studies of fulvestrant in metastatic breast cancer.

Expert opinion: Even if fulvestrant showed only marginal activity in two phase II trials, it shouldn’t be abandoned but instead further developed in EC. Firstly, the dose of fulvestrant used in these trials was too low from today’s point of view. Secondly, the available literature on other endocrine agents is full of limitations and does not provide a gold standard. Furthermore, given the activity of mTOR inhibitors in EC, there may also be synergistic effects, given the cross-regulation of ER and the PI3K/AKT/mTOR pathway. The authors suggest that a prospective, phase II trial in ER positive RMEC would help to further explore the efficacy and tolerability of fulvestrant together with a mTOR inhibitor.     

Arachidonic acid‐containing phosphatidylcholine characterized by consolidated plasma and liver lipidomics as an early onset marker for tamoxifen‐induced hepatic phospholipidosis

Lipid profiling has emerged as an effective approach to not only screen disease and drug toxicity biomarkers but also understand their underlying mechanisms of action. Tamoxifen, a widely used antiestrogenic agent for adjuvant therapy against estrogen‐positive breast cancer, possesses side effects such as hepatic steatosis and phospholipidosis (PLD). In the present study, we administered tamoxifen to Sprague–Dawley rats and used lipidomics to reveal tamoxifen‐induced alteration of the hepatic lipid profile and its association with the plasma lipid profile. Treatment with tamoxifen for 28 days caused hepatic PLD in rats. We compared the plasma and liver lipid profiles in treated vs. untreated rats using a multivariate analysis to determine differences between the two groups. In total, 25 plasma and 45 liver lipids were identified and altered in the tamoxifen‐treated group. Of these lipids, arachidonic acid (AA)‐containing phosphatidylcholines (PCs), such as PC (17:0/20:4) and PC (18:1/20:4), were commonly reduced in both plasma and liver. Conversely, tamoxifen increased other phosphoglycerolipids in the liver, such as phosphatidylethanolamine (18:1/18:1) and phosphatidylinositol (18:0/18:2). We also examined alteration of AA‐containing PCs and some phosphoglycerolipids in the pre‐PLD stage and found that these lipid alterations were initiated before pathological alteration in the liver. In addition, changes in plasma and liver levels of AA‐containing PCs were linearly associated. Moreover, levels of free AA and mRNA levels of AA‐synthesizing enzymes, such as fatty acid desaturase 1 and 2, were decreased by tamoxifen treatment. Therefore, our study demonstrated that AA‐containing PCs might have potential utility as novel and predictive biomarkers for tamoxifen‐induced PLD. Copyright © 2017 John Wiley & Sons, Ltd.     

Profile of differentially expressed intratumoral cytokines to predict the immune-polarizing side effects of tamoxifen in breast cancer treatment

Factors within the tissue of breast cancer (BC) may shift the polarization of CD4+ T cells towards Th2 direction. This tendency can promote tumor development and be enhanced by the use of tamoxifen during the treatment. Thus, the patients with low levels of tumor-induced Th2 polarization prior to tamoxifen treatment may better endure the immune-polarizing side effects (IPSE) of tamoxifen and have better prognoses. Estimation of Th2 polarization status should help predict the IPSE among tamoxifen-treated patients and guide the use of tamoxifen among all BC patients before the tamoxifen therapy. Here, we report profiling of differentially expressed (DE) intratumoral cytokines as a signature to evaluate the IPSE of tamoxifen. The DE genes of intratumoral CD4+ T cells (CD4 DEGs) were identified by gene expression profiles of purified CD4+ T cells from BC patients and validated by profiling of cultured intratumoral CD4+ T cells. Functional enrichment analyses showed a directed Th2 polarization of intratumoral CD4+ T cells. To find the factors inducing the Th2 polarization of CD4+ T cells, we identified 995 common DE genes of bulk BC tissues (BC DEGs) by integrating five independent datasets. Five DE cytokines observed in bulk BC tissues with dysregulated receptors in the intratumoral CD4+ T cells were selected as the predictor of the IPSE of tamoxifen. The patients predicted to suffer low IPSE (low Th2 polarization) had a significantly lower distant relapse risk than the patients predicted to suffer high IPSE in independent datasets (n = 608; HR = 4.326, P = 0.000897; HR = 2.014, P = 0.0173; HR = 2.72, P = 0.04077). Patients predicted to suffer low IPSE would benefit from tamoxifen treatment (HR = 2.908, P = 0.03905). The DE intratumoral cytokines identified in this study may help predict the IPSE of tamoxifen and justify the use of tamoxifen in BC treatment.     

Ductal Carcinoma In Situ: Recent History and Areas of Controversy

The authors provide a perspective on the rapidly evolving field of prognostic analyses designed to quantify the risk of local recurrence in conservatively treated ductal carcinoma in situ (DCIS). These include morphologic features variously defined, nomograms, algorithms and multi‐gene expression assays‐all of which have completed against the perceived conclusions of the randomized trials of irradiation and Tamoxifen for DCIS: “all subsets benefit”. At present the majority of newly diagnosed DCIS can be adequately treated with surgery alone. A number will require irradiation to achieve acceptable local control, and a minority will require mastectomy regardless of adjuvant treatments. Differences in the definition of prognostic factors and in the methods used to establish them is a major reason for the lack of consensus in treatment recommendation.     

Post‐marketing assessment of generic tamoxifen in Brazilian breast cancer patients

Generic formulations of tamoxifen are commonly prescribed to oestrogen receptor‐positive breast cancer patients at the Brazilian National Cancer Institute (INCA). We carried out a post‐marketing surveillance of the generic tamoxifen formulation in current use at INCA, by comparing plasma concentrations of the parent drug and metabolites obtained with the generic vs the reference formulation. Thirty patients participated in an open‐label, bracketed protocol, comprising 3 successive phases of 30‐32 days each: the generic formulation was used in phases 1 and 3 and the reference formulation in phase 2. Two blood samples were collected in the last 4 days of each phase, for LC‐MS/MS quantification of tamoxifen and metabolites in plasma. The median plasma concentrations (ng/mL) for the reference formulation were as follows: tamoxifen, 135.0 (CI 95% 114.2‐155.8); endoxifen, 35.3 (30.0‐40.8); and 4‐hydroxytamoxifen, 4.8 (4.2‐5.4). The endoxifen/tamoxifen plasma concentration ratio was 0.27 (0.21‐0.25). ANOVA detected no statistically significant difference in plasma concentrations of tamoxifen, metabolites or the endoxifen/tamoxifen ratio among the three phases. The genetic component (rGC) of the CYP2D6‐mediated conversion of tamoxifen into endoxifen, estimated using the repeated drug administration procedure across the three phases, was 0.87, pointing to an important component of genetic variability. In conclusion, this first post‐marketing surveillance trial of oncologic generic drugs carried out in Brazilian patients verified the switchability between the reference and the generic tamoxifen formulation currently used at our institution. The adopted bracketed protocol adds confidence to this conclusion and may serve as a frame for future trials of post‐marketing assessment of other generic drug products.     

Breast Cancer Chemoprevention among High‐risk Women and those with Ductal Carcinoma In Situ

Chemoprevention with the anti‐estrogens, tamoxifen, raloxifene, and aromatase inhibitors, reduce breast cancer incidence in high‐risk women; however, uptake has been poor (<5%) in the prevention setting. We assessed use of anti‐estrogens for breast cancer prevention, among high‐risk women seen at an academic breast center, to observe how uptake rates compare in this setting. We collected data on demographics, breast cancer risk factors, and health behaviors via self‐administered questionnaires and medical chart abstraction. Women eligible for chemoprevention with anti‐estrogens had a 5‐year predicted breast cancer risk according to the Gail model of ≥1.67%, history of lobular or ductal carcinoma in situ (LCIS/DCIS), and/or BRCA mutation. We dichotomized anti‐estrogen use as ever or never. Predictors of use were evaluated using multivariable log‐binomial regression. Of 412 high‐risk women enrolled, 316 (77%) were eligible for chemoprevention. Among eligible women, 55% were non‐Hispanic white, 29% Hispanic, 8% non‐Hispanic black, and 7% Asian. Women were grouped based upon their highest category of breast cancer risk (in descending order): BRCA mutation carriers (3%), DCIS (40%), LCIS (22%), and 5‐year Gail risk ≥1.67% (36%). Among those eligible for chemoprevention, 162 (51%) had ever initiated anti‐estrogen therapy (71% tamoxifen, 23% raloxifene, 5% aromatase inhibitor). Anti‐estrogen use was highest among women with DCIS (73%). In multivariable analysis, women with a 5‐year Gail risk ≥1.67% had approximately a 20% lower likelihood of anti‐estrogen use compared to women with DCIS (p = 0.01). In the primary prevention setting, excluding women diagnosed with DCIS, anti‐estrogen use was 37%. Multivariable analysis showed differences in uptake by education and potentially by race/ethnicity. Among high‐risk women seen at a breast center, anti‐estrogen use for chemoprevention was relatively high as compared to the published literature. Clinicians can support high‐risk women by effectively communicating breast cancer risk and enhancing knowledge about the risks and benefits of chemoprevention.     

Milestones in Breast Cancer Treatment

Modern treatment started in the 1880s with Halsted's mastectomy. The next milestone—a century later—was breast‐conserving surgery, with equivalent survival but better esthetic outcomes than mastectomy. Sentinel node biopsy, introduced in the 1990s, was a milestone that permitted avoidance of axillary dissection if the sentinel node was disease‐free. Chemotherapy was established for early breast cancer in the 1980s and its efficacy continues to improve; however side effects remain a concern, particularly since chemotherapy does not benefit most patients. External whole breast irradiation was introduced with conservative surgery, as it reduces recurrences. By the 2000s, 3‐week regimens had been shown equivalent to standard 6‐week regimens—easing pressure on patients and radiation centers. Intraoperative partial breast irradiation is potentially more beneficial as it permits complete local treatment in a single session; however, trials show that patients must be very carefully selected. From the 1990s irradiation technology was combined with imaging and computer technologies to produce equipment that directs radiation to more precisely defined target volumes, allowing increased dose to the target and markedly reduced dose to nearby tissues. Irradiation systems are evolving rapidly but are being implemented without data on long‐term morbidity or efficacy, while costs rise steeply. The first targeted treatment was tamoxifen, a selective estrogen receptor inhibitor. Since its widespread use starting in the 1980s, tamoxifen has saved the lives or prolonged the survival of millions with estrogen‐positive disease; it is cheap and has limited (but not negligible) side effects. The same cannot be said of newer targeted treatments like trastuzumab and pertuzumab, which, although effective against human epidermal growth factor receptor 2‐positive cancer, come with important side effects and huge costs. Breast cancer mortality is declining in rich countries, but treatments have become more demanding and more expensive, so the outlook for the increasing numbers of women worldwide who develop the disease is uncertain.     

Cardiomyocyte-Specific Deletion of Gsk3α Mitigates Post–Myocardial Infarction Remodeling,Contractile Dysfunction,and Heart Failure

BackgroundInjury due to myocardial infarction (MI) is largely irreversible. Once an infarct has occurred, the clinical goal becomes limiting remodeling, preserving left ventricular function, and preventing heart failure. Although traditional approaches (e.g., β-blockers) partially preserve left ventricular function, novel strategies are needed to limit ventricular remodeling post-MI.ObjectivesThe aim of this study was to determine the role of glycogen synthase kinase–3α (GSK-3α) in post-MI remodeling.MethodsMice with cardiomyocyte-specific conditional deletion of Gsk3α and littermate controls underwent sham or MI surgery. Heart function was assessed using serial M-mode echocardiography.ResultsGsk3α deletion in the heart markedly limits remodeling and preserves left ventricular function post-MI. This is due at least in part to dramatic thinning and expansion of the scar in the control hearts, which was less in the heart of knockout (KO) mice. In contrast, the border zone in the KO mice demonstrated a much thicker scar, and there were more viable cardiomyocytes within the scar/border zone. This was associated with less apoptosis and more proliferation of cardiomyocytes in the KO mice. Mechanistically, reduced apoptosis was due, at least in part, to a marked decrease in the Bax/Bcl-2 ratio, and increased cardiomyocyte proliferation was mediated through cyclin E1 and E2F-1 in the hearts of the KO mice.ConclusionsTaken together, these findings show that reducing GSK-3α expression in cardiomyocytes limits ventricular remodeling and preserves cardiac function post-MI. Specifically targeting GSK-3α could be a novel strategy to limit adverse remodeling and heart failure.