Estrogen Receptor Alpha Gene Amplification Is an Independent Predictor of Long-Term Outcome in Postmenopausal Patients with Endocrine-Responsive Early Breast Cancer

Breast cancer: pathogenesis and treatments

Breast cancer, characterized by unique epidemiological patterns and significant heterogeneity, remains one of the leading causes of malignancy-related deaths in women. The increasingly nuanced molecular subtypes of breast cancer have enhanced the comprehension and precision treatment of this disease. The mechanisms of tumorigenesis and progression of breast cancer have been central to scientific research, with investigations spanning various perspectives such as tumor stemness, intra-tumoral microbiota, and circadian rhythms. Technological advancements, particularly those integrated with artificial intelligence, have significantly improved the accuracy of breast cancer detection and diagnosis. The emergence of novel therapeutic concepts and drugs represents a paradigm shift towards personalized medicine. Evidence suggests that optimal diagnosis and treatment models tailored to individual patient risk and expected subtypes are crucial, supporting the era of precision oncology for breast cancer. Despite the rapid advancements in oncology and the increasing emphasis on the clinical precision treatment of breast cancer, a comprehensive update and summary of the panoramic knowledge related to this disease are needed. In this review, we provide a thorough overview of the global status of breast cancer, including its epidemiology, risk factors, pathophysiology, and molecular subtyping. Additionally, we elaborate on the latest research into mechanisms contributing to breast cancer progression, emerging treatment strategies, and long-term patient management. This review offers valuable insights into the latest advancements in Breast Cancer Research, thereby facilitating future progress in both basic research and clinical application.

Estrogen Regulated Genes Compel Apoptosis in Breast Cancer Cells, Whilst Stimulate Antitumor Activity in Peritumoral Immune Cells in a Janus-Faced Manner

Background: Breast cancer incidence and mortality exhibit a rising trend globally among both premenopausal and postmenopausal women, suggesting that there are serious errors in our preventive and therapeutic measures. Purpose: Providing a series of valuable, but misunderstood inventions highlighting the role of increasing estrogen signaling in prevention and therapy of breast cancer instead of its inhibition. Results: 1. Breast cells and breast cancer cells with germline BRCA1/2 mutations similarly show defects in liganded estrogen receptor (ER) signaling, demonstrating its role in genomic instability and cancer initiation. 2. In breast tumors, the increased expression of special receptor family maybe an effort for self-directed improvement of genomic defects, while the weakness or loss of receptors indicates a defect requiring medical repair. 3. ER overexpression in breast cancer cells is capable of strengthening estrogen signaling and DNA repair, while in ER negative tumors, HER2 overexpression tries to upregulate unliganded ER activation and genome stabilization. 4. ER-positive breast cancers responsive to endocrine therapy may show a compensatory ER overexpression resulting in a transient tumor response. Breast cancers non-responsive to antiestrogen treatment exhibit HER2-overexpression for compensating the complete inhibition of hormonal ER activation. 5. In breast tumors, somatic mutations serve upregulation of ER activation via liganded or unliganded pathway helping genome stabilization and apoptotic death. 6. The mutual communication between breast cancer and its inflammatory environment is a wonderful partnership among cells fighting for genome stabilization and apoptotic death of tumor. 7. In breast cancers, there is no resistance to genotoxic or immune blocker therapies, but rather, the nonresponsive tumor cells exhaust all compensatory possibilities against therapeutic damages. Conclusions: Understanding the behavior and ambition of breast cancer cells may achieve a turn in therapy via applying supportive care instead of genotoxic measures.

Androgen receptor and estrogen receptor variants in prostate and breast cancers

The androgen receptor (AR) and estrogen receptor alpha (ERα) are steroid receptor transcription factors with critical roles in the development and progression of prostate and breast cancers. Advances in the understanding of mechanisms underlying the ligand-dependent activation of these transcription factors have contributed to the development of small molecule inhibitors that block AR and ERα actions. These inhibitors include competitive antagonists and degraders that directly bind the ligand binding domains of these receptors, luteinizing hormone releasing hormone (LHRH) analogs that suppress gonadal synthesis of testosterone or estrogen, and drugs that block specific enzymes required for biosynthesis of testosterone or estrogen. However, resistance to these therapies is frequent, and is often driven by selection for tumor cells with alterations in the AR or ESR1 genes and/or alternatively spliced AR or ESR1 mRNAs that encode variant forms AR or ERα. While most investigations involving AR have been within the context of prostate cancer, and the majority of investigations involving ERα have been within the context of breast cancer, important roles for AR have been elucidated in breast cancer, and important roles for ERα have been elucidated in prostate cancer. Here, we will discuss the roles of AR and ERα in breast and prostate cancers, outline the effects of gene- and mRNA-level alterations in AR and ESR1 on progression of these diseases, and identify strategies that are being developed to target these alterations therapeutically.

Estrogen Receptor Alpha Mutations, Truncations, Heterodimers, and Therapies

Annual breast cancer (BCa) deaths have declined since its apex in 1989 concomitant with widespread adoption of hormone therapies that target estrogen receptor alpha (ERα), the prominent nuclear receptor expressed in ∼80% of BCa. However, up to ∼50% of patients who are ER+ with high-risk disease experience post endocrine therapy relapse and metastasis to distant organs. The vast majority of BCa mortality occurs in this setting, highlighting the inadequacy of current therapies. Genomic abnormalities to ESR1, the gene encoding ERα, emerge under prolonged selective pressure to enable endocrine therapy resistance. These genetic lesions include focal gene amplifications, hotspot missense mutations in the ligand binding domain, truncations, fusions, and complex interactions with other nuclear receptors. Tumor cells utilize aberrant ERα activity to proliferate, spread, and evade therapy in BCa as well as other cancers. Cutting edge studies on ERα structural and transcriptional relationships are being harnessed to produce new therapies that have shown benefits in patients with ESR1 hotspot mutations. In this review we discuss the history of ERα, current research unlocking unknown aspects of ERα signaling including the structural basis for receptor antagonism, and future directions of ESR1 investigation. In addition, we discuss the development of endocrine therapies from their inception to present day and survey new avenues of drug development to improve pharmaceutical profiles, targeting, and efficacy.

Digital image analysis allows objective stratification of patients with silent PIT1-lineage pituitary neuroendocrine tumors

Studies describing the clinical presentation and prognosis of patients with silent PIT1 (pituitary specific transcription factor)-lineage pituitary neuroendocrine tumors (PitNETs) are rare. We identified patients with positive PIT1 tumor staining but without evidence of hormone hypersecretion at a tertiary center. Clusters were obtained according to cell morphology and immunostaining from each patient's digitally segmented whole slide image. We compared the clinical presentations, radiological features, and prognoses of the different clusters. We identified 146 patients (68 male, 42.9 ± 14.1 years old) with silent PIT1-lineage PitNETs. Morphology clustering suggested that tumors with large nuclei and apparent eccentricity were associated with a higher proportion of aggressiveness and a higher hazard of recurrence [hazard ratio (HR): 2.64, (95% CI, 1.06-6.55), p = 0.037]. Immunohistochemical clustering suggested that tumors with thyroid stimulating hormone (TSH) staining or all negative PIT1-lineage hormones were associated with a higher proportion of aggressiveness and a higher risk of recurrence [HR: 12.4, (95% CI, 1.60-93.5), p = 0.015]. We obtained three-tier risk profiles by combining morphological and immunohistochemical clustering. Patients with the high-risk profile presented the highest recurrence rate compared with those in the medium-risk and low-risk profiles [HR: 3.54, (95% CI, 1.40-8.93), p = 0.002]. In conclusion, digital image analysis based on cell morphology and immunohistochemical staining allows objective stratification of patients with silent PIT1-lineage tumors. Typical morphological characteristics of high-risk tumors are large tumor nuclei and high eccentricity, and typical immunostaining characteristics are TSH staining or negative staining for all PIT1-lineage hormones.

Revisiting Estrogen for the Treatment of Endocrine-Resistant Breast Cancer: Novel Therapeutic Approaches

Estrogen receptor (ER)-positive breast cancer is the most common subtype, representing 70-75% of all breast cancers. Several ER-targeted drugs commonly used include the selective estrogen receptor modulator (SERM), tamoxifen (TAM), aromatase inhibitors (AIs) and selective estrogen receptor degraders (SERDs). Through different mechanisms of action, all three drug classes reduce estrogen receptor signaling. Inevitably, resistance occurs, resulting in disease progression. The counterintuitive action of estrogen to inhibit ER-positive breast cancer was first observed over 80 years ago. High-dose estrogen and diethylstilbestrol (DES) were used to treat metastatic breast cancer accompanied by harsh side effects until the approval of TAM in the 1970s. After the development of TAM, randomized trials comparing TAM to estrogen found similar or slightly inferior efficacy but much better tolerability. After decades of research, it was learned that estrogen induces tumor regression only after a period of long-term estrogen deprivation, and the mechanisms of tumor regression were described. Despite the long history of breast cancer treatment with estrogen, this therapeutic modality is now revitalized due to the development of novel estrogenic compounds with improved side effect profiles, newly discovered predictive biomarkers, the development of non-estrogen small molecules and new combination therapeutic approaches.

Nomograms for Predicting Disease-Free Survival Based on Core Needle Biopsy and Surgical Specimens in Female Breast Cancer Patients with Non-Pathological Complete Response to Neoadjuvant Chemotherapy

PURPOSE

While a pathologic complete response (pCR) is regarded as a surrogate endpoint for pos-itive outcomes in breast cancer (BC) patients receiving neoadjuvant chemotherapy (NAC), fore-casting the prognosis of non-pCR patients is still an open issue. This study aimed to create and evaluate nomogram models for estimating the likelihood of disease-free survival (DFS) for non-pCR patients.

METHODS

A retrospective analysis of 607 non-pCR BC patients was conducted (2012-2018). After converting continuous variables to categorical variables, variables entering the model were progressively identified by univariate and multivariate Cox regression analyses, and then pre-NAC and post-NAC nomogram models were developed. Regarding their discrimination, ac-curacy, and clinical value, the performance of the models was evaluated by internal and external validation. Two risk assessments were performed for each patient based on two models; patients were separated into different risk groups based on the calculated cut-off values for each model, including low-risk (assessed by the pre-NAC model) to low-risk (assessed by the post-NAC model), high-risk to low-risk, low-risk to high-risk, and high-risk to high-risk groups. The DFS of different groups was assessed using the Kaplan-Meier method.

RESULTS

Both pre-NAC and post-NAC nomogram models were built with clinical nodal (cN) status and estrogen receptor (ER), Ki67, and p53 status (all p < 0.05), showing good discrimination and calibration in both internal and external validation. We also assessed the performance of the two models in four subtypes, with the tri-ple-negative subtype showing the best prediction. Patients in the high-risk to high-risk subgroup have significantly poorer survival rates (p < 0.0001).

CONCLUSION

Two robust and effective nomo-grams were developed to personalize the prediction of DFS in non-pCR BC patients treated with NAC.