Receiving Tamoxifen Therapy Research Articles

Clinicopathologic Features, Treatment Patterns, and Disease Outcomes in a Modern, Prospective Cohort of Young Women Diagnosed with Ductal Carcinoma In Situ.

Ductal carcinoma in situ (DCIS) is uncommon and understudied in young women. The objective of this study is to describe clinicopathologic features, treatment, and oncologic outcomes in a modern cohort of women aged ≤40 years with DCIS. Patients with DCIS were identified from the Young Women's Breast Cancer Study, a multisite prospective cohort of women diagnosed with stage 0-IV breast cancer at age ≤40 years, enrolled from 2006 to 2016. Clinical data were collected from patient surveys and medical records. Pathologic features were examined by central review. Data were summarized with descriptive statistics and groups were compared with χ2 and Fisher's exact tests. Among the 98 patients included, median age of diagnosis was 38 years; 36 (37%) patients were symptomatic on presentation. DCIS nuclear grade was high in 35%, intermediate in 50%, and low in 15% of lesions; 36% of lesions had comedonecrosis. The majority of patients underwent bilateral mastectomy (57%), 16 (16%) underwent unilateral mastectomy, and 26 (27%) underwent lumpectomy, most of whom received radiation. Few (13%) patients were receiving tamoxifen therapy 1 year postdiagnosis. Over a median follow-up of 8.4 years, six patients (6%) had disease recurrence, including five locoregional and one distant event. A high proportion of young women with DCIS underwent mastectomy with or without contralateral prophylactic mastectomy. Although DCIS was frequently symptomatic on presentation and exhibited unfavorable pathologic factors, clinicopathologic features were overall heterogeneous and few recurrences occurred. This underscores the need for careful consideration of treatment options in young women with DCIS.

Ovarian Cysts Formation in Patients with Breast Cancer on Tamoxifen Therapy in Iraqi Female

Background: Tamoxifen shows complex hormonal actions, breast cancer that occurs in the premenopausal period treated with tamoxifen created huge quantities of estrogen. Objectives: This study was conducted to determine the prevalence of ovarian cysts formation in tamoxifen treatments by ultra-sonographic examinations. Method: A prospective study was carried out in the Oncology and Nuclear medicine specialist Hospital, Mosul/Iraq. There were 14 premenopausal and 36 postmenopausal patients. The inclusion criteria were patients with breast cancer who had been on tamoxifen therapy. Fifty patients were included during a period of 10 months. The following parameters were assessed by ultrasound, endometrial thickness and ovaries conditions, with clinical parameters, age of patients, weight, and associated symptoms. Results: A total of 50 patients getting tamoxifen management, 14 (28%) of them are premenopausal range their age was between 25 to 44 years, and 36 (72%) postmenopausal range their age was between 45 to 78 years. There’s a correlation between the age group of patients and ovarian changes and cystic formation the ovarian cysts were diagnosed. There’s a relation between increased endometrial thickness and incidence of ovarian cyst in patients receiving tamoxifen therapy and mild relation between increased endometrial thickness and RT ovarian cystic formation in which the p-value of RT ovary = .049. In contrast, the LT ovary shows a relation with p-value = .025, which was significant. Conclusion: Ovarian cysts are common genital tract complications of tamoxifen therapy, which had been developed in this study in about 20% of cases. Ovarian cysts can grow together with premenopausal and postmenopausal patients getting tamoxifen for treated breast cancer.

DLGAP1-AS2 promotes estrogen receptor signalling and confers tamoxifen resistance in breast cancer.

Tamoxifen is a first-line endocrine agent and is often used to treat estrogen receptor-positive (ER+) breast cancer. Unfortunately, approximately 30-40% of patients who received tamoxifen therapy experience recurrence or progression to a fatal advanced stage due to tamoxifen resistance. However, the mechanisms of tamoxifen resistance remain unclear. The expression of lncRNA DLGAP1 antisense RNA 2 (DLGAP1-AS2) was detected by qPCR. The effect of DLGAP1-AS2 on tamoxifen resistance was evaluated by MTT, colony formation, TUNEL and flow cytometric assays. The mechanisms by which DLGAP1-AS2 regulates tamoxifen resistance were investigated through qPCR, RNA pull-down assays and RNA immunoprecipitation (RIP) assays. Our results showed that DLGAP1-AS2 is significantly upregulated in breast cancer and that tamoxifen can induce DLGAP1-AS2 expression. Further investigation suggested that upregulation of DLGAP1-AS2 can increase cell viability and inhibit apoptosis, while downregulation of DLGAP1-AS2 results in the opposite effects. Mechanistically, DLGAP1-AS2 can bind to the AFF3 protein to inhibit its degradation, which further promotes ER signalling. Our research clarified that DLGAP1-AS2 promotes ER signalling to induce tamoxifen resistance and that targeting DLGAP1-AS2 might be a promising strategy to overcome tamoxifen resistance in breast cancer.

MicroRNA-221 and tamoxifen resistance in luminal-subtype breast cancer patients: A case-control study

BackgroundAround 70% of breast cancers (BCs) are estrogen receptor-α (ERα)-positive. Adjuvant endocrine therapy is used to reduce estrogen levels and inhibit signal transduction through the ER. The anti-estrogen drugs that are most commonly used in endocrine therapy belong to the selective ER modulator (SERM) class and include tamoxifen. Although it has been used for three decades in cases of early-stage and ERα-positive BC, resistance to tamoxifen is a common problem. microRNAs (miRNAs) have a potential role in demonstrating BC resistance to tamoxifen therapy. Hence, there is a need to investigate the expression of miRNA-221 (miR-221) in luminal-subtype BC patients receiving tamoxifen therapy. MethodsThis case-control study investigated luminal-subtype BC patients who had undergone endocrine therapy for at least 1 year. The case group comprised patients with local or metastatic recurrence, and the control group comprised patients without local or metastatic recurrence. ResultsThere was a significant difference in miR-221 expression (p = 0.005) between the case and control groups. There were no significant differences between the groups that were positive and negative for the progesterone receptor (PR) (p = 0.25), had high and low marker of proliferation Ki-67 levels (p = 0.60), were positive and negative for lymphovascular invasion (p = 0.14), and had stage 2 and stage 3 cancer (p = 0.25). ConclusionmiR-221 expression was higher in tamoxifen-resistant BC cases. miR-221 is a potential biomarker of tamoxifen resistance.

Hormone Receptor Subtype in Ductal Carcinoma in Situ: Prognostic and Predictive Roles of the Progesterone Receptor.

BackgroundWe investigated the prognostic and predictive roles of the hormone receptor (HRc) subtype in patients with ductal carcinoma in situ (DCIS). We focused on identifying the roles of the progesterone receptor (PR) independent of estrogen receptor (ER) status.MethodsNationwide data of 12,508 female patients diagnosed with DCIS with a mean follow‐up period of 60.7 months were analyzed. HRc subtypes were classified as ER−/PR−, ER−/PR+, ER+/PR−, and ER+/PR+ based on ER and PR statuses. The Cox proportional hazards model was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).ResultsThe ER+/PR+ group showed better prognoses than the ER+/PR− and ER−/PR− groups in the patients who received tamoxifen therapy (p = .001 and p = .031, respectively). HRc subtype was an independent prognostic factor (p = .028). The tamoxifen therapy group showed better survival than the patients who did not receive tamoxifen, but only in the ER+/PR+ subgroup (p = .002). Tamoxifen therapy was an independent prognostic factor (HR, 0.619; 95% CI, 0.423 − 0.907; p = .014). PR status was a favorable prognostic factor in patients with DCIS who received tamoxifen therapy (p < .001), and it remained a prognostic factor independent of ER status (HR, 0.576; 95% CI, 0.349 − 0.951; p = .031).ConclusionThe HRc subtype can be used as both a prognostic and predictive marker in patients with newly diagnosed DCIS. Tamoxifen therapy can improve overall survival in the ER+/PR+ subtype. PR status has significant prognostic and predictive roles independent of ER status. Testing for the PR status in addition to the ER status is routinely recommended in patients with DCIS to determine the HRc subtype in clinical settings.Implications for PracticeThe hormone receptor (HRc) subtype was an independent prognostic factor, and the estrogen receptor (ER)+/progesterone receptor (PR) + subtype showed a better survival in patients with ductal carcinoma in situ (DCIS) who received tamoxifen therapy. PR was an independent prognostic factor independent of ER, and PR was a favorable prognostic factor in patients with DCIS who received tamoxifen therapy. The HRc subtype could be used as both a prognostic and predictive marker in patients with newly diagnosed DCIS. Testing of PR status in addition to ER status is routinely recommended for patients with DCIS to determine the HRc subtype in clinical settings.

Assessment of 25-Year Survival of Women With Estrogen Receptor–Positive/ERBB2-Negative Breast Cancer Treated With and Without Tamoxifen Therapy

Clinically used breast cancer markers, such as tumor size, tumor grade, progesterone receptor (PR) status, and Ki-67 status, are known to be associated with short-term survival, but the association of these markers with long-term (25-year) survival is unclear. To assess the association of clinically used breast cancer markers with long-term survival and treatment benefit among postmenopausal women with lymph node-negative, estrogen receptor [ER]-positive and ERBB2-negative breast cancer who received tamoxifen therapy. This study was a secondary analysis of data from a subset of 565 women with ER-positive/ERBB2-negative breast cancer who participated in the Stockholm tamoxifen (STO-3) randomized clinical trial. The STO-3 clinical trial was conducted from 1976 to 1990 and comprised 1780 postmenopausal women with lymph node-negative breast cancer who were randomized to receive adjuvant tamoxifen therapy or no endocrine therapy. Complete 25-year follow-up data through December 31, 2016, were obtained from Swedish national registers. Immunohistochemical markers were reannotated in 2014. Data were analyzed from April to December 2020. Patients in the original STO-3 clinical trial were randomized to receive 2 years of tamoxifen therapy vs no endocrine therapy. In 1983, patients who received tamoxifen therapy without cancer recurrence during the 2-year treatment and who consented to continued participation in the STO-3 study were further randomized to receive 3 additional years of tamoxifen therapy or no endocrine therapy. Distant recurrence-free interval (DRFI) by clinically used breast cancer markers was assessed using Kaplan-Meier and multivariable Cox proportional hazards analyses adjusted for age, period of primary diagnosis, tumor size (T1a and T1b [T1a/b], T1c, and T2), tumor grade (1-3), PR status (positive vs negative), Ki-67 status (low vs medium to high), and STO-3 clinical trial arm (tamoxifen treatment vs no adjuvant treatment). A recursive partitioning analysis was performed to evaluate which markers were able to best estimate long-term DRFI. The study population comprised 565 postmenopausal women (mean [SD] age, 62.0 [5.3] years) with lymph node-negative, ER-positive/ERBB2-negative breast cancer. A statistically significant difference in long-term DRFI was observed by tumor size (88% for T1a/b vs 76% for T1c vs 63% for T2 tumors; log-rank P < .001) and tumor grade (81% for grade 1 vs 77% for grade 2 vs 65% for grade 3 tumors; log-rank P = .02) but not by PR status or Ki-67 status. Patients with smaller tumors (hazard ratio [HR], 0.31 [95% CI, 0.17-0.55] for T1a/b tumors and 0.58 [95% CI, 0.38-0.88] for T1c tumors) and grade 1 tumors (HR, 0.48; 95% CI, 0.24-0.95) experienced a significant reduction in the long-term risk of distant recurrence compared with patients with larger (T2) tumors and grade 3 tumors, respectively. A significant tamoxifen treatment benefit was observed among patients with larger tumors (HR, 0.53 [95% CI, 0.32-0.89] for T1c tumors and 0.34 [95% CI, 0.16-0.73] for T2 tumors), lower tumor grades (HR, 0.24 [95% CI, 0.07-0.82] for grade 1 tumors and 0.50 [95% CI, 0.31-0.80] for grade 2 tumors), and PR-positive status (HR, 0.38; 95% CI, 0.24-0.62). The recursive partitioning analysis revealed that tumor size was the most important characteristic associated with long-term survival, followed by clinical trial arm among patients with larger tumors. This secondary analysis of data from the STO-3 clinical trial indicated that, among the selected subgroup of patients, tumor size followed by tumor grade were the markers most significantly associated with long-term survival. Furthermore, a significant long-term tamoxifen treatment benefit was observed among patients with larger tumors, lower tumor grades, and PR-positive tumors.

The response of anti-VEGF therapy and tamoxifen withdrawal of tamoxifen-induced cystoid macular edema in the same patient

BackgroundNumerous cases with ocular toxicity secondary to tamoxifen have been reported, and became more apparent with keratopathy, cataract, optic neuritis, macular holes, crystalline retinopathy with or without cystoid macular edema (CME). Withdrawing tamoxifen with the approval of the oncologist is the major treatment for cases with tamoxifen-induced retinopathy.Case presentationWe herein reported a patient with a two-year history of painless and reduced visual acuity in both eyes who received tamoxifen therapy for 6 years. Tamoxifen-induced rentinopathy with CME showed significant development even though the patient has already discontinued tamoxifen treatment for 6 months. Anatomic improvements after intravitreal ranibizumab injection in both eyes were significant but were temporary. Surprisingly, CME in both eyes has been resolved spontaneously after 10 months in the penultimate visit without any therapy.ConclusionIntravitreal ranibizumab injection temporarily improved the anatomy of the eyes in a case with tamoxifen-induced CME, and only tamoxifen withdrawal can bring a sustained effect.

Uterine Fibroid in Breast Cancer Patients receiving Tamoxifen Therapy

Abstract&#x0D; Objective: Selective estrogen receptor modulators (SERMs) such as tamoxifen play a role in increasing the risk of developing uterine Fibroid.Methods: Case reportCase: Mrs. 47 years old, Para 6, presented with chief complaints of vaginal bleeding since a year ago. The patient was diagnosed with breast carcinoma 4 years ago and has had a right mastectomy followed by 6 cycles of chemotherapy which is then continued with tamoxifen treatment for 4 years, USG examination revealed uterine myoma to which we performed bilateral salphingoophorectomy hysterectomy, with anatomic pathology results of a uterine Fibroid and chronic endometritis.Conclusion: Selective estrogen receptor modulators (SERMs) such as tamoxifen exhibit antagonistic reactions in breast tissue which makes it appropriate to be used in the treatment of breast cancer. However, they can also be potentially agonistic on estrogen receptors in the uterus, which can cause the growth of uterine Fibroid. Nevertheless, the benefits of adjuvant tamoxifen for breast cancer outweighs its potential for developing uterine Fibroid and endometrial carcinoma, because metastatic breast cancer will always be fatal, whereas uterine myoma and endometrial cancer caused by the effects of tamoxifen can be prevented by regular evaluation and total hysterectomy.Keywords: breast cancer,tamoxifen, uterine fibroid,&#x0D; &#x0D; Abstrak&#x0D; Tujuan: Selektif estrogen reseptor modulator (SERMs) seperti tamoksifen berperan dalam meningkatkan risiko mengembangkan mioma uteri. Metode: Laporan KasusKasus: Ny 47 Thn Para 6, datang dengan keluhan perdarahan dari jalan lahir yang dirasakan ibu selama 1 tahun ini, pasien telah menderita kanker payudara 4 tahun yang lalu dan telah dilakukan mastektomi mammae dextra dilanjutkan kemoterapi 6 siklus kemudian dilanjutkan dengan pengobatan tamoksifen selama 4 tahun ini, dari pemeriksaan USG didapatkan adanya mioma uteri kemudian dilanjutkan dengan tindakan histerektomi salphingooforektomi bilateral, dengan hasil patologi anatomi suatu mioma uteri dan endometritis kronis.Kesimpulan: Selektif estrogen reseptor modulator (SERMs) seperti tamoksifen merupakan reaksi antagonis reseptor estrogen pada jaringan payudara yang digunakan dalam pengobatan kanker payudara, tetapi dapat berpotensi agonis pada reseptor estrogen pada uterus sehingga dapat menyebabkan pertumbuhan mioma uteri. Tetapi penggunaan tamoksifen ajuvan untuk kanker payudara lebih bermanfaat dibandingkan dengan potensinya untuk mengembangkan mioma uteri dan karsinoma endometrium, karena kanker payudara metastatik akan selalu berakibat fatal, sedangkan mioma uteri dan kanker endometrium yang ditimbulkan oleh efek tamoksifen dapat dicegah dengan evaluasi teratur dan dilakukan tindakan total histerektom.Kata kunci: kanker payudara, mioma uteri, tamoksifen

Assessment of Tamoxifen-Related Endometrial Changes in Premenopausal Female Patients With Diffusion-Weighted Magnetic Resonance Imaging.

To evaluate tamoxifen-related endometrial changes in premenopausal female patients with diffusion-weighted magnetic resonance imaging (DWI). This prospective study was performed on 71 premenopausal female patients (mean age, 41 years) who were receiving tamoxifen therapy. All patients underwent magnetic resonance imaging with DWI of the pelvis and hysteroscopic-guided endometrial biopsy. The apparent diffusion coefficient (ADC) values of the endometrial plate were calculated and correlated with pathological results. The mean ADCs of tamoxifen-related benign endometrial lesions (1.35 ± 0.19 and 1.32 ± 0.13 × 10 mm/s) were significantly higher (P = 0.001) than those of normal endometrial plate (0.95 ± 0.11 and 0.93 ± 0.11 × 10 mm/s) by both reviewers, respectively. The cutoff ADC values used to differentiate tamoxifen-related benign endometrial lesions from normal endometrium were 1.07 and 1.02 × 10 mm/s with areas under the curve of 0.94 and 0.93 and accuracy of 94.4 and 95.8 by both reviewers, respectively. The mean ADC values of endometrial polyp (EP) (1.44 ± 0.19 and 1.42 ± 0.22 × 10 mm/s) were significantly higher (P = 0.001) than those of endometrial hyperplasia (EH) (1.25 ± 0.19 and 1.23 ± 0.19 × 10 mm/s) by both reviewers, respectively. The cutoff ADC values used to differentiate EP from EH were 1.38 × 10 and 1.36 × 10 mm/s with areas under the curve of 0.81 and 0.77 and accuracy of 80% and 70% by both reviewers, respectively. There was an insignificant difference in ADC value between typical and atypical EH. The ADC values of endometrial cancer (0.80 and 0.78 × 10 mm/s) were lower than those of tamoxifen-related benign endometrial lesions. The final diagnosis was normal endometrium (n = 36), benign endometrial lesions either EH (n = 17), or EP (n = 16), and endometrial cancer in only 2 patients. We concluded that DWI helps in detection and characterization of different tamoxifen-related endometrial changes in the premenopausal female patients.

Sonographic Study of Female Pelvic Organs in Breast Cancer Patients Taking Tamoxifen: Clinical Correlation

Background: As most of breast cancer patients are treated with Tamoxifen, different effects of this drug in patients should be evaluated since no such study is carried out in Bangladesh till date.&#x0D; Objective: The purpose of the present study was to evaluate sonographic changes of female genital organs in breast cancer patients treated with Tamoxifen and to correlate these changes with duration of Tamoxifen treatment and gynecological symptoms.&#x0D; Methodology: This randomized double-blind clinical trial was carried out in Delta Medical College Hospital, Dhaka, Bangladesh from May 2017 to April 2018 for a period of one (1) year. The participants were breast cancer patients which were divided into three groups named as group I patients. The patients of these group were on Tamoxifen therapy. The patients of group II were without Tamoxifen therapy. The patients of group III had completed Tamoxifen therapy. All participants underwent ultrasonography.&#x0D; Results: Patients receiving Tamoxifen therapy had significantly more thickened endometrium compared to other groups (26.6% in group I, 5% in group II and3% in group III). Similarly, abnormal sonographic findings and mean uterine volume were higher in group I compared to other two groups. Endometrial thickness and uterine volume showed significant positive correlation with duration of Tamoxifen therapy (p &lt;0.0001). The endometrial thickness and uterine volume greatly increased after two years of Tamoxifen therapy while it was reverse in group III. Gynecological symptoms had no significant relations with sonographic abnormalities and thickened endometrium.&#x0D; Conclusion: Tamoxifen therapy is associated with increased endometrial thickness, uterine volume and abnormal sonographic findings, compared to patients without Tamoxifen or completing Tamoxifen therapy.&#x0D; Journal of Current and Advance Medical Research 2020;7(1): 17-23

Retinal structural changes in patients receiving tamoxifen therapy by spectral-domain optical coherence tomography

Purpose: To evaluate choroidal thickness, ganglion cell complex (GCC) and photoreceptor outer segment (PROS) length were measured in patients with breast cancer undergoing tamoxifen therapy, using spectral-domain optical coherence tomography (SD-OCT); results were compared with those for normal eyes.Materials and methods: Forty-four patients with breast cancer, undergoing tamoxifen therapy, and 41 healthy controls were included in this prospective, comparative study. All participants underwent a complete ophthalmologic evaluation and SD-OCT. Subfoveal, nasal (nasal distance to fovea 500, 1000, 1500 μm), and temporal (temporal distance to fovea 500, 1000, 1500 μm) choroidal thickness measurements were performed using the enhanced depth imaging mode of SD-OCT. Using an Early Treatment Diagnostic Retinopathy Study (ETDRS) circle at the macular level, the automated retinal segmentation software was applied to determine the thickness of the GCC. PROS length was determined manually, as the distance from the inner surface of the ellipsoid zone to the inner surface of retina pigment epithelium.Results: The mean choroidal thickness was statistically greater in the tamoxifen group than controls in all quadrants (p < 0.001 for all quadrants). Of all tamoxifen users (44 eyes of 44 patients), 33 eyes (75%) had uncomplicated pachychoroid (UCP). Pachychoroid pigment epitheliopathy (PPE) was detected in five tamoxifen-group patients (11.3%). Patients with PPE in one eye had UCP in the fellow eye. Central serous chorioretinopathy findings were observed in one patient. Tamoxifen users had statistically lower GCC thickness in all inner rings of the ETDRS inlay and in the nasal outer ring only (p = 0.027, 0.002, 0.002, 0.001, and 0.030, respectively). No statistically significant difference in mean subfoveal PROS length was found between the groups.Conclusions: SD-OCT provides valuable information for identifying structural changes and evaluating ocular findings in patients receiving tamoxifen therapy. Increased choroidal thickness, PPE and thinning GCC were detected in tamoxifen users. These OCT findings may be an early indicator of retinal toxicity for patients undergoing tamoxifen therapy in the follow-up period.

Association of CYP2D6*10 (c. 100 C>T) Genotype with Z-END Concentration in Patients with Breast Cancer Receiving Tamoxifen Therapy in Indonesian Population.

Tamoxifen (TAM) is a frequently used hormonal prodrug for patients with breast cancer that needs to be activated by cytochrome P450 2D6 (CYP2D6) into Zusammen-endoxifen (Z-END). The purpose of the study was to determine the association between CYP2D6*10 (c.100C>T) genotype and attainment of the plasma steady-state Z-END minimal threshold concentration (MTC) in Indonesian women with breast cancer. A cross-sectional study was performed in 125 ambulatory patients with breast cancer consuming TAM at 20 mg/day for at least 4 months. The frequency distribution of CYP2D6*10 (c.100C>T) genotypes (C/C: wild type; C/T: heterozygous mutant; T/T: homozygous mutant) was detected using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), the results of which were subsequently confirmed by sequencing. The genotypes were categorized into plasma Z- END concentrations of <5.9 ng/mL and ≥5.9 ng/mL, which were measured using ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Percentages of C/C, CT, and T/T genotypes were 22.4%, 29.6%, and 48.8%, respectively. Median (25-75%) Z-END concentrations in C/C, C/T, and T/T genotypes were 9.58 (0.7-6.0), 9.86 (0.7-26.6), and 3.76 (0.9-26.6) ng/mL, respectively. Statistical analysis showed a significant difference in median Z-END concentration between patients with T/T genotype and those with C/C or C/T genotypes (p<0.001). There was a significant association between CYP2D6*10 (c.100C>T) genotypes and attainment of plasma steady-state Z-END MTC (p<0.001). There was a significant association between CYP2D6*10 (c.100C>T) and attainment of plasma steady-state Z-END MTC in Indonesian breast cancer patients receiving TAM at a dose of 20 mg/day.

Abstract 2295: Influence of endocrine therapy on the ratio of androgen receptor (AR) to estrogen receptor (ER) positive circulating epithelial tumor cells (CETCs) in breast cancer

Abstract Background: The androgen receptor (AR) is expressed in the majority of breast cancers and across the main breast cancer subtypes. Despite the high frequency of AR expression in breast cancer its appraisal remains controversial because its role is complex, dependent on the hormonal milieu. The aim of the current study was to investigate the frequency of AR and ER positive CETCs in breast cancer patients. Material and Methods: The number of vital CETCs was determined from blood of 66 patients suffering from breast cancer and the expression of AR and ER on these cells was investigated using the maintrac method. Results: Numbers of CETCs/ml blood were significantly higher in patients with advanced disease as compared to patients with early stage disease. The fraction of AR positive CETCs was significantly higher than the fraction of ER positive CETCs (90% vs. 50%; p&amp;lt;0.001). Patients with positive lymph nodes had less AR positive CETCs as compared to patients with negative lymph node status. The AR:ER ratio was higher in patients receiving tamoxifen therapy as compared to patients without tamoxifen therapy whereas treatment with aromatase inhibitor had no influence on AR:ER ratio. Conclusions: The ratio of AR to ER positive CETCs, obviously, is influenced by endocrine therapy, more specifically therapy with tamoxifen. Since AR expression seems to be responsible to resistance to endocrine therapy this may provide a new biomarker to select patients who might benefit from combination treatment of ER and AR inhibitors. Note: This abstract was not presented at the meeting. Citation Format: Monika Pizon, Dorothea Schott, Daniel Lux, Ulrich Pachmann, Katharina Pachmann. Influence of endocrine therapy on the ratio of androgen receptor (AR) to estrogen receptor (ER) positive circulating epithelial tumor cells (CETCs) in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2295.

Long-Term Use of Tamoxifen Is Associated With a Decreased Subsequent Meningioma Risk in Patients With Breast Cancer: A Nationwide Population-Based Cohort Study

Background: Earlier studies have indicated a relatively higher risk of occurring meningioma among female breast cancer survivors and have suggested that tamoxifen might decrease this risk. The present study evaluated whether tamoxifen use in breast cancer patients can reduce the risk of meningioma. Methods: We designed a population-based cohort study by using data from the National Health Insurance system of Taiwan to assess this issue. Between January 1, 2000, and December 31, 2008, women with breast cancer and of age ≥20 years were included. They were divided into two groups: those who had not received tamoxifen therapy and those who had. The Cox’s proportion hazard regression analysis was conducted to estimate the effects of tamoxifen treatment and the subsequent meningioma risk. Results: We identified a total of 50,442 tamoxifen users and 30,929 non-tamoxifen users. Tamoxifen users had a borderline significantly lower overall risk of meningioma than non-tamoxifen users [adjusted hazard ratio (aHR) = 0.64, 95% confidence interval (95% CI) = 0.40–1.02]. A statistically significant difference was found in those patients with tamoxifen treatment duration longer than 1,500 days (aHR = 0.42, 95% CI = 0.19–0.91) or with cumulative dosage exceeding 26,320 mg (aHR = 0.44, 95% CI = 0.22–0.88). Furthermore, no statistically significant joint effect of aromatase inhibitors and tamoxifen on the occurrence of meningioma among breast cancer patients was seen. Conclusion: Tamoxifen users had a non-significantly (36%) lower risk of developing meningioma than did tamoxifen non-users; however, our data indicated that tamoxifen therapy is associated with a reduced meningioma risk for Taiwanese breast cancer patients receiving long duration or high cumulative dosage treatment with tamoxifen.

The CYP2C19 rs4917623 single nucleotide polymorphism to predict tamoxifen efficacy in estrogen receptor-positive breast cancer patients.

e12001 Background: Tamoxifen is a selective estrogen receptor modulator that is widely used to treat estrogen receptor (ER)-positive breast cancer. However, not all patients benefit from the incorporation of tamoxifen into an adjuvant therapy. This is also the case when tamoxifen is used in chemoprevention, since only half of participants benefit from the drug. In order to improve treatment response, we attempted to identify single nucleotide polymorphisms (SNPs) that correlated with tamoxifen efficacy. Methods: ER-positive breast cancer patients at our hospital were enrolled on this study between January 2007 and September 2010. The primary endpoint was ER-positive breast cancer-free survival. We examined 17 SNPs in these patients. The survival benefit associated with each genotype was determined with a log-rank test, and the hazard ratio was analyzed using a Cox proportional-hazards model. Results: The median follow-up time of the 320 patients enrolled on the study was 3298 days. Of 240 patients who received any endocrine therapy, ER-positive breast cancer-free survival in patients with the 2q35 rs13387042 AA genotype was significantly shorter than in those who had the AG or GG genotype (p &lt; 0.0001), and the hazard ratio was significantly higher (HR 8.83; 95% CI 2.09–25.53, p = 0.0064). Of the 145 patients who received tamoxifen therapy, there was a trend among ER-positive breast cancer patients with the CYP2C19 rs4917623 TT genotype to have a shorter disease-free period (p = 0.0635) when compared to patients with TC or CC genotypes. Similarly, there was a trend for the TT genotype patients to exhibit a higher hazard ratio (HR 2.62; 95% CI 0.86–7.55, p = 0.0861). Conclusions: The rs4917623 SNP in the CYP2C19 gene, which encodes a metabolic enzyme, predicts tamoxifen efficacy. This finding will facilitate selection of ER-positive breast cancer patients for tamoxifen treatment; it may also be useful for selection of patients most likely to benefit from tamoxifen-dependent chemoprevention.

TARBP2-Enhanced Resistance during Tamoxifen Treatment in Breast Cancer.

Tamoxifen is the most widely used hormone therapy in estrogen receptor-positive (ER+) breast cancer, which accounts for approximately 70% of all breast cancers. Although patients who receive tamoxifen therapy benefit with respect to an improved overall prognosis, resistance and cancer recurrence still occur and remain important clinical challenges. A recent study identified TAR (HIV-1) RNA binding protein 2 (TARBP2) as an oncogene that promotes breast cancer metastasis. In this study, we showed that TARBP2 is overexpressed in hormone therapy-resistant cells and breast cancer tissues, where it enhances tamoxifen resistance. Tamoxifen-induced TARBP2 expression results in the desensitization of ER+ breast cancer cells. Mechanistically, tamoxifen post-transcriptionally stabilizes TARBP2 protein through the downregulation of Merlin, a TARBP2-interacting protein known to enhance its proteasomal degradation. Tamoxifen-induced TARBP2 further stabilizes SOX2 protein to enhance desensitization of breast cancer cells to tamoxifen, while similar to TARBP2, its induction in cancer cells was also observed in metastatic tumor cells. Our results indicate that the TARBP2-SOX2 pathway is upregulated by tamoxifen-mediated Merlin downregulation, which subsequently induces tamoxifen resistance in ER+ breast cancer.

Influence of endocrine therapy on the ratio of androgen receptor (AR) to estrogen receptor (ER) positive circulating epithelial tumor cells (CETCs) in breast cancer

BackgroundThe androgen receptor (AR) is expressed in the majority of breast cancers and across the main breast cancer subtypes. Despite the high frequency of AR expression in breast cancer its appraisal remains controversial because its role is complex, dependent on the hormonal milieu. The aim of the current study was to investigate the frequency of AR and ER positive CETCs in breast cancer patients.MethodsThe number of vital CETCs was determined from blood of 66 patients suffering from breast cancer and the expression of AR and ER on these cells was investigated using the maintrac method.ResultsNumbers of CETCs/mL blood were significantly higher in patients with advanced disease as compared to patients with early stage disease. The fraction of AR positive CETCs was significantly higher than the fraction of ER positive CETCs (90% vs. 50%; P < 0.001). Patients with positive lymph nodes had less AR positive CETCs as compared to patients with negative lymph node status. The AR:ER ratio was higher in patients receiving tamoxifen therapy as compared to patients without tamoxifen therapy whereas treatment with aromatase inhibitor had no influence on AR:ER ratio.ConclusionsThe ratio of AR to ER positive CETCs, obviously, is influenced by endocrine therapy, more specifically therapy with tamoxifen. Since AR expression seems to be one of the possible mechanism of resistance to endocrine therapy this may provide a new biomarker to select patients who might benefit from combination treatment of ER and AR inhibitors.

Improving Access and Adherence to Endocrine Therapy With Nurse-Based Intervention

Purpose The majority of women with breast cancer from low-income countries, including Ethiopia, present with advanced clinical stage disease, which results in limited and difficult therapeutic options and high mortality rates. In Ethiopia, breast cancer is the most common cancer. We found that 70% of breast cancer cases in Ethiopia are hormone receptor positive. Endocrine therapy is one of the treatment options recommended for breast cancer but that is highly underutilized in the country. Recommendations on interventions to improve uptake and adherence to therapy exist, but studies that have assessed the feasibility of implementing these are limited. Our study (n = 107) in rural Ethiopia revealed an estimated 53% 2-year survival rate in patients who underwent surgery only. In our pilot study, of 51 eligible patients 26 initiated therapy and one half of those adhered after 1 year. Our study aims to evaluate the effectiveness of using a trained breast nurse navigator to improve patient adherence to tamoxifen therapy among patients with breast cancer in rural Ethiopia. Methods A cluster randomized intervention trial is being carried out in rural hospitals in southwestern Ethiopia from February 2018 to June 2019. We use hospitals in clusters as the units of randomization. The sample size includes four per intervention arm and control arm, with each cluster comprised of approximately 15 patients. Before intervention, all patients in the hospitals will receive tamoxifen therapy free of charge. Hormone receptor status of the breast cancer specimen will be determined before the initiation of therapy or throughout the course of therapy. The primary outcome of this trial is adherence to endocrine therapy on the basis of objective and subjective measures. Data will be collected with a prospective repeated measures approach. Analysis will be based on an intention-to-treat principle. Results The trial aims to provide evidence on the effectiveness of the breast nurse intervention to improve adherence to long-term endocrine therapy and answer the following research question: does the nursing intervention improve long-term treatment adherence by patients to endocrine therapy compared with those who receive usual care services? Conclusion These data are essential to maximize the impact of trained nurse-based interventions on adherence to endocrine (tamoxifen) therapy among patients with breast cancer on follow-up. AUTHORS' DISCLOSURES OF POTENTIAL CONFLICTS OF INTEREST The following represents disclosure information provided by authors of this manuscript. All relationships are considered compensated. Relationships are self-held unless noted. I = Immediate Family Member, Inst = My Institution. Relationships may not relate to the subject matter of this manuscript. For more information about ASCO's conflict of interest policy, please refer to www.asco.org/rwc or ascopubs.org/jco/site/ifc . Eva J. Kantelhardt Travel, Accommodations, Expenses: Daiichi Sankyo Oncology Europe

Impact of hormonal therapy and other adjuvant therapies on contralateral breast volume change after implant-based breast reconstruction.

BackgroundAdjuvant therapy after breast surgery, including tamoxifen or aromatase inhibitors, improves the postoperative outcomes and long-term survival of breast cancer patients. The aim of this study was to determine whether volume changes occurred in the contralateral breast during hormonal or other adjuvant therapies.MethodsThis study reviewed 90 patients who underwent unilateral breast reconstruction between September 2012 and April 2018 using tissue expanders and a permanent implant after the surgical removal of breast cancer. The volume of the contralateral breast was measured using a cast before the first (tissue expander insertion) and second (permanent implant change) stages of surgery. Changes in breast volume were evaluated to determine whether adjuvant therapy such as hormonal therapy, chemotherapy, and radiation therapy influenced the volume of the contralateral breast.ResultsThe group receiving tamoxifen therapy demonstrated a significant decrease in volume compared with the group without tamoxifen (−7.8% vs. 1.0%; P=0.028). The aromatase inhibitor–treated group showed a significant increase in volume compared with those who did not receive therapy (−6.2% vs. 4.5%; P=0.023). There were no significant differences between groups treated with other hormonal therapy, chemotherapy, or radiation therapy. ConclusionsPatients who received tamoxifen therapy showed a significant decrease in volume in the contralateral breast, while no significant change in weight or body mass index was found. Our findings suggest that we should choose smaller implants for premenopausal patients, who have a high likelihood of receiving tamoxifen therapy.

Bioinformatics-based identification of miR-542-5p as a predictive biomarker in breast cancer therapy

BackgroundTamoxifen is the first-line hormone therapy for estrogen receptor alpha positive (ERα+) breast cancer. However, about 40% of patients with ERα + breast cancer who receive tamoxifen therapy eventually develop resistance resulting in a poor prognosis. The aim of this study was to mine available data sets in the Gene Expression Omnibus (GEO) database, including in vitro (cell lines) and in vivo (tissue samples), and to identify all miRNAs associated with tamoxifen resistance (TamR) in breast cancer. Secondly, this study aimed to predict the key gene regulatory networks of newly found TamR-related miRNAs and evaluate the potential role of the miRNAs and targets as potential prognosis biomarkers for breast cancer patients.ResultMicroarray data sets from two different studies were used from the GEO database: 1. GSE66607: miRNA of MCF-7 TamR cells; 2. GSE37405: TamR tissues. Differentially expressed microRNAs (miRNAs) were identified in both data sets and 5 differentially expressed miRNAs were found to overlap between the two data sets. Profiles of GSE37405 and data from the Kaplan-Meier Plotter Database (KMPD) along with Gene Expression Profiling Interactive Analysis (GEPIA) were used to reveal the relationship between these 5 miRNAs and overall survival. The results showed that has-miR-542-5p was the only miRNA associated with overall survival of ERα + breast cancer patients who received adjuvant tamoxifen. Targets of has-miR-542-5p were predicted by miRanda and TargetScan, and the mRNA expression of the three 3 target gene, Tyrosine 3-Monooxygenase/Tryptophan 5-Monooxygenase Activation Protein Beta (YWHAB), Lymphocyte Antigen 9 (LY9), and Secreted Frizzled Related Protein 1 (SFRP1) were associated with overall survival in 2 different databases. Copy-number alterations (CNAs) of SFRP1 confer survival disadvantage to breast cancer patients and alter the mRNA expression of SFRP1 in cBioPortal database.ConclusionThis study indicates that miRNA has-miR-542-5p is associated with TamR and can predict prognosis of breast cancer patients. Furthermore, has-miR-542-5p may be acting through a mechanism involving the target genes YWHAB, LY9, and SFRP1. Overall, has-miR-542-5p is a predictive biomarker and potential target for therapy of breast cancer patients.