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Although HER2-low breast cancer (BC) constitutes almost 50% of all BC types, its impact on the pathological complete response (pCR) rate and survival in early BC is uncertain. As a result, a systematic review was conducted to compare the pCR rate and survival of HER2-low and HER2-zero BC in the neoadjuvant chemotherapy (NACT) setting. Two reviewers independently performed literature searches using EMBASE, PubMed, and Cochrane Libraries internet databases up to June 2023. Finally, 29 studies with 178,294 patients were included. HER2-low BC had a considerably lower pCR rate compared to HER2-zero BC in the entire population (Risk Ratio [RR] = 0.68, P < .001) and in the hormone receptor (HR)-positive subgroup (RR = 0.73, P = .009), but not in the HR-negative subgroup (RR = 0.99, P = .755). Furthermore, patients with HER2-low BC exhibited prolonged disease-free survival (DFS) and overall survival (OS) compared to those with HER2-zero BC, observed in both the entire cohort (DFS: P = .004; OS: P = .008) and the HR-negative subgroup (DFS: P = .009; OS: P < .001). In the HR-positive population, OS was superior in HER2-low BC patients (P < .001), whereas no significant differences in DFS were observed (P = .064). Our findings imply that the pCR rate and prognosis of HER2-low BC are distinguished from those of HER2-zero BC in early BC treated with NACT, which contributes to a better knowledge of the BC subgroup.
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Neoplasias de la Mama , Terapia Neoadyuvante , Receptor ErbB-2 , Humanos , Terapia Neoadyuvante/métodos , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/metabolismo , Receptor ErbB-2/metabolismo , Femenino , Quimioterapia Adyuvante/métodos , Supervivencia sin Enfermedad , Pronóstico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéuticoRESUMEN
BACKGROUND: Mixed invasive ductolobular breast cancer (MIDLC) is a rare histological subtype of breast cancer (BC), with components of both invasive ductal cancer (IDC) and invasive lobular cancer (ILC). Its clinicopathological features and outcomes have not been well characterized. METHOD: The National Cancer Database 2010-2017 was reviewed to identify women with stage I-III BCs. Univariate analysis was performed using Chi-square or Wilcoxon rank-sum tests and multivariable analysis with logistic regression to predict surgical decisions. Survival was assessed using multivariable Cox proportional hazards regression analysis. RESULTS: We identified 955,828 women with stage I-III BCs (5.7% MIDLC, 10.3% ILC, and 84.0% IDC). MIDLC was more like ILC than IDC in terms of multicentricity (14.2% MIDLC, 13.0% ILC, 10.0% IDC), hormone receptor positivity (96.6% MIDLC, 98.2% ILC, 81.2% IDC), and use of neoadjuvant chemotherapy (NAC; 5.8% MIDLC, 5.2% ILC, 10.8% IDC). 744,607 women underwent upfront surgery. The mastectomy rates were 42.3% for MIDLC, 46.5% for ILC, and 33.3% for IDC (all p < 0.001). With 5.5 years of median follow-up, the adjusted overall survival in the upfront surgery hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) biological subgroup was better in MIDLC (hazard ratio 0.88, p < 0.001) and ILC (hazard ratio 0.91, p < 0.001) than in IDC. Like ILC, MIDLC also had a lower pathological complete response to NAC than IDC (12.3% MIDLC, 7.3% ILC, 28.6% IDC). CONCLUSIONS: MIDLC displays a mixed pattern of characteristics favoring features of ILC compared with IDC, with favorable 5-year overall survival compared with IDC within the HR+/HER2- subtype who underwent upfront surgery.
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Neoplasias de la Mama , Carcinoma Ductal de Mama , Carcinoma Lobular , Humanos , Femenino , Neoplasias de la Mama/cirugía , Neoplasias de la Mama/tratamiento farmacológico , Carcinoma Ductal de Mama/patología , Carcinoma Lobular/patología , Mastectomía , Receptor ErbB-2/metabolismoRESUMEN
Identifying objective biological subtypes that predict long-term functional outcomes is crucial for understanding neurobiological mechanisms and identifying potential targets. Using resting-state functional magnetic resonance imaging data from 178 patients and 70 controls, we explored social function patterns using latent profile analysis. Long-term outcomes were compared among the biological subtypes using K-means clustering. Partial least squares regression (PLSR) was used to identify gene expression profiles associated with alterations in activity by leveraging transcriptional data from the Allen Human Brain Atlas. In patients with more functional impairment, left medial pulvinar (PM) exhibited significantly lower regional homogeneity of brain activity (ReHo, [95% CI (0.06-0.27), P = 0.002), a finding validated in the independent cohort. Functional connectivity between PM and secondary visual cortex displayed a suggestive decrease. Patients belonging to "higher pulvinar ReHo - better information processing" demonstrated better long-term outcomes and acute treatment response [95% CI (11.2-34.4), P < 0.001]. The PLSR component of imaging-transcriptomic associations partly explained the ReHo differences among patients with varying levels of functional impairment. It revealed enrichment of genes in the synaptic signaling pathway. Pathological changes in the pulvinar may affect social functioning. Higher pulvinar ReHo and better information processing, two objective biomarkers, have a predictive value for better long-term functional outcomes.
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Pulvinar , Esquizofrenia , Humanos , Esquizofrenia/diagnóstico por imagen , Pulvinar/diagnóstico por imagen , Encéfalo , Análisis por Conglomerados , CogniciónRESUMEN
BackgroundBeing complex and highly heterogeneous with regard to the etiology and clinical manifestations of depression， neuroimaging studies make a breakthrough for exploring the biological subtypes of depression， while the current data-driven approach for the identification of subtyping depression using structural magnetic resonance imaging （MRI） data is insufficient. ObjectiveTo explore the biological subtypes of depression using diffusion tensor imaging （DTI） and machine learning methods. MethodsA total of 127 patients with depression who attended Beijing Anding Hospital from September 2017 to August 2021 and met the Diagnostic and Statistical Manual of Mental Disorders， fourth edition （DSM-IV） diagnostic criteria were included， and another 80 healthy individuals matched for gender and age were recruited through advertisements in surrounding communities during the same period. DTI findings， demographic characteristics and clinical data were collected from all participants. Tract-based spatial statistics （TBSS） and the Johns Hopkins University （JHU） white matter probability maps were used to extract fractional anisotropy （FA） values of white matter tracts. A semi-supervised machine learning technique was used to identify the subtypes， and the FA values for whole brain white matter of patients and controls were compared. ResultsPatients with depression were classified into two biological subtypes. FA values in multiple tracts including corpus callosum and corona radiata of subtype I patients were smaller than those of healthy controls （P<0.01， FDR corrected）， and FA values in middle cerebellar peduncle， left superior cerebellar peduncle and left cerebral peduncle of subtype II patients were larger than those of healthy controls （P<0.01， FDR-corrected）. Baseline Hamilton Depression Scale-17 item （HAMD-17） score yielded no statistical difference between subtype I and subtype II patients （P>0.05）， while subtype I patients scored lower on HAMD-17 than subtype II patients after 12 weeks of treatment （t=2.410， P<0.05）. ConclusionDepression patients exhibit two biological subtypes with distinct patterns of white matter damage. Furthermore， the subtypes respond differently to the medication treatment. ［Funded by the National Key Research and Development Program of China （number， 2016YFC1307200）， the Scientific Research and Cultivation Program of Beijing Municipal Hospitals （number，PX2023066）， Beijing Anding Hospital， Capital Medical University （number，YJ201904， YJ201911）； www.chictr.org.cn number： ChiCTR-OOC-17012566］
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OBJECTIVES: To investigate whether antemortem MRI-based atrophy subtypes of Alzheimer's disease (AD) differ in neuropathological features and comorbid non-AD pathologies at postmortem. METHODS: From the ADNI cohort, we included individuals with: antemortem MRI evaluating brain atrophy within 2y before death; antemortem diagnosis of AD dementia/mild cognitive impairment; postmortem-confirmed AD neuropathologic change. Antemortem atrophy subtypes were modeled as continuous phenomena based on a recent conceptual framework: typicality (spanning limbic-predominant AD to hippocampal-sparing AD) and severity (spanning typical AD to minimal atrophy AD). Postmortem neuropathological evaluation included AD hallmarks, amyloid-beta and tau as well as non-AD pathologies, alpha-synuclein and TAR DNA-binding protein-43 (TDP-43). We also investigated the overall concomitance across these pathologies. Partial correlations assessed the associations between antemortem atrophy subtypes and postmortem neuropathological outcomes. RESULTS: In 31 individuals (26 AD dementia/5 mild cognitive impaired, mean age=80y, 26% females), antemortem typicality was significantly negatively associated with neuropathological features, including amyloid-beta (rho=-0.39 overall), tau (rho=-0.38 regionally), alpha-synuclein (rho=-0.39 regionally), TDP-43 (rho=-0.49 overall), and concomitance of pathologies (rho=-0.59 regionally). Limbic-predominant AD was associated with higher Thal phase, neuritic plaque density, and presence of TDP-43 compared to hippocampal-sparing AD. Regionally, limbic-predominant AD showed higher presence of tau and alpha-synuclein pathologies in medial temporal structures, higher presence of TDP-43 and concomitance of pathologies subcortically/cortically compared to hippocampal-sparing AD. Antemortem severity was significantly negatively associated with concomitance of pathologies (rho=-0.43 regionally), such that typical AD showed higher concomitance of pathologies than minimal atrophy AD. DISCUSSION: We provide a direct antemortem-to-postmortem validation, highlighting the importance of understanding atrophy-based heterogeneity in AD relative to AD and non-AD pathologies. We suggest that: (a) typicality and severity in atrophy reflect differential aspects of susceptibility of the brain to AD and non-AD pathologies; (b) limbic-predominant AD and typical AD subtypes share similar biological pathways, making them more vulnerable to AD and non-AD pathologies compared to hippocampal-sparing AD, which may follow a different biological pathway. Our findings provide a deeper understanding of associations of atrophy subtypes in AD with different pathologies, enhancing prevailing knowledge of biological heterogeneity in AD and could contribute towards tracking disease progression and designing clinical trials in the future.
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Breast cancer is a heterogeneous disease. Surrogate classification of intrinsic subtypes of invasive carcinomas by combined immunohistochemistry for estrogen receptor (ER), progesterone receptor (PR), HER2, and Ki67 (4-IHC) has increased steadily since the 2011 St Gallen symposium, due to its rapid subtyping of tumors at a reasonable cost. An important step in improving 4-IHC reproducibility and reliability will be to provide reference values from the routine use of standardized 4-IHC followed by image analysis. The aims of the current study were (1) to analyze invasive breast carcinomas using standardized 4-IHC and quantitative image analysis and (2) to compare the results obtained in the classification of biological subtypes using current Ki67 and PR threshold values proposed by different authors to sub-classifying the luminal A-like and the luminal B-like (HER2-negative) subtypes. Five hundred twenty-one tumors were analyzed by standardized immunohistochemistry, with automatic image analysis, and HER2 FISH technique. Positivity for ER was found in 82.7% and for PR in 70.1% of cases. Using the Allred scoring system, hormone receptor results showed a bimodal distribution, particularly for ER. HER2 positivity was found in 15.7% of cases, and the mean Ki67 score was 32.3%. Using the most recently proposed surrogate definitions for the classification of luminal breast cancer subtypes, the percentages of different subtypes that we found were similar to those published with genomic platforms: 40.7% luminal A-like, 32.4% luminal B-like/HER2-negative, 9.8% luminal B-like/HER2-positive, 6.0% HER2-positive, and 11.1% triple negative. Standardized 4-IHC with automatic image analysis constitutes a low-cost method for surrogate definitions of biological subtypes of breast cancer that delivers accurate results in a day.
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Adenocarcinoma Mucinoso/clasificación , Biomarcadores de Tumor/metabolismo , Neoplasias de la Mama/clasificación , Carcinoma Ductal de Mama/clasificación , Carcinoma Lobular/clasificación , Interpretación de Imagen Asistida por Computador/normas , Inmunohistoquímica/normas , Adenocarcinoma Mucinoso/diagnóstico , Adenocarcinoma Mucinoso/metabolismo , Adenocarcinoma Mucinoso/patología , Adulto , Anciano , Anciano de 80 o más Años , Biopsia con Aguja Gruesa , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Carcinoma Ductal de Mama/diagnóstico , Carcinoma Ductal de Mama/metabolismo , Carcinoma Ductal de Mama/patología , Carcinoma Lobular/diagnóstico , Carcinoma Lobular/metabolismo , Carcinoma Lobular/patología , Femenino , Humanos , Persona de Mediana EdadRESUMEN
BACKGROUND: The exploration and therapy of depression is aggravated by heterogeneous etiological mechanisms and various comorbidities. With the growing trend towards big data in psychiatry, research and therapy can increasingly target the individual patient. This novel objective requires special methods of analysis. OBJECTIVE: The possibilities and challenges of the application of big data approaches in depression are examined in closer detail. MATERIAL AND METHODS: Examples are given to illustrate the possibilities of big data approaches in depression research. Modern machine learning methods are compared to traditional statistical methods in terms of their potential in applications to depression. RESULTS: Big data approaches are particularly suited to the analysis of detailed observational data, the prediction of single data points or several clinical variables and the identification of endophenotypes. A current challenge lies in the transfer of results into the clinical treatment of patients with depression. CONCLUSION: Big data approaches enable biological subtypes in depression to be identified and predictions in individual patients to be made. They have enormous potential for prevention, early diagnosis, treatment choice and prognosis of depression as well as for treatment development.
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Macrodatos , Depresión , Psiquiatría , Investigación , Humanos , Psiquiatría/métodos , Psiquiatría/tendencias , Investigación/normas , Investigación/tendenciasRESUMEN
The objective of this study is to analyze magnetic resonance imaging shrinkage pattern of tumor regression after neoadjuvant chemotherapy and to evaluate its relationship with biological subtypes and pathological response. We reviewed the magnetic resonance imaging studies of 51 patients with single mass-enhancing lesions (performed at time 0 and at the II and last cycles of neoadjuvant chemotherapy). Tumors were classified as Luminal A, Luminal B, HER2+, and Triple Negative based on biological and immunohistochemical analysis after core needle biopsy. We classified shrinkage pattern, based on tumor regression morphology on magnetic resonance imaging at the II cycle, as concentric, nodular, and mixed. We assigned a numeric score (0: none; 1: low; 2: medium; 3: high) to the enhancement intensity decrease. Pathological response on the surgical specimen was classified as complete (grade 5), partial (grades 4-3), and non-response (grades 1-2) according to Miller and Payne system. Fisher test was used to relate shrinkage pattern with biological subtypes and final pathological response. Seventeen patients achieved complete response, 25 partial response, and 9 non-response. A total of 13 lesions showed nodular pattern, 20 concentric, and 18 mixed. We found an association between concentric pattern and HER2+ (p < 0.001) and mixed pattern and Luminal A lesions (p < 0.001). We observed a statistical significant correlation between concentric pattern and complete response (p < 0.001) and between mixed pattern and non-response (p = 0.005). Enhancement intensity decrease 3 was associated with complete response (p < 0.001). Shrinkage pattern and enhancement intensity decrease may serve as early response indicators after neoadjuvant chemotherapy. Shrinkage pattern correlates with tumor biological subtypes.
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Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/tratamiento farmacológico , Imagen por Resonancia Magnética , Terapia Neoadyuvante , Mama/diagnóstico por imagen , Mama/efectos de los fármacos , Mama/patología , Neoplasias de la Mama/clasificación , Neoplasias de la Mama/patología , Medios de Contraste/administración & dosificación , Femenino , Humanos , Resultado del TratamientoRESUMEN
PURPOSE: The 70-year threshold determines whether patients are eligible or not for the breast cancer screening program in Germany. It is not known whether this age threshold also influences the choice of adjuvant treatment and ultimate outcome. METHODS: 3463 patients were analyzed from the clinical cancer registry Regensburg (Germany) with primary, non-metastatic invasive breast cancer diagnosed between 2000 and 2012. The distribution of tumor biological subtypes was evaluated in breast cancer patients both in those eligible for screening (ESG, 50-69 years) and those not eligible for screening (NESG, ≥70 years). Local and systemic therapies in different subtypes as well as overall survival (OS) were analyzed. RESULTS: 2171 patients (62.7%) pertained to the ESG and 1292 patients (37.3%) referred to the NESG. The distribution of the common subtypes Luminal A, Luminal B, HER2-like, and Basal-like was comparable in both groups. Treatment varied considerably with less systemic therapies in all subtypes in patients in the NESG. Regarding local therapies, patients in the NESG also received less surgery and less radiotherapy. As to Luminal A patients, best OS was seen in patients receiving endocrine therapy (ET) (7-year OS of 95.6%) and CHT plus ET (7-year OS of 93.1%) in the ESG. In the NESG, best OS was seen in patients receiving CHT plus ET (7-year OS of 95.2%), whereas patients receiving only ET had a 7-year OS of 73.9%. CONCLUSIONS: Despite similar tumor biology, elderly patients are undertreated regarding both systemic and local therapies compared to younger patients, leading to reduced OS.
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Neoplasias de la Mama/patología , Neoplasias de la Mama/terapia , Receptor ErbB-2/metabolismo , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/metabolismo , Quimioterapia Adyuvante , Femenino , Alemania , Disparidades en Atención de Salud , Humanos , Tamizaje Masivo , Mastectomía , Persona de Mediana Edad , Pronóstico , Radioterapia Adyuvante , Análisis de Supervivencia , Resultado del TratamientoRESUMEN
BACKGROUND: Breast cancer is the most common among women in our country, and its treatment is based on prognostic factors to categorize patients into different risk groups. In this study, the clinical and pathological features that play a role as a prognostic factor in a representative population with breast cancer in México are described. MATERIAL AND METHODS: A descriptive analysis of the clinical and pathological features of women diagnosed with breast cancer, in a period from June 2005 to May 2014; registered in a database and calculated by simple frequencies. RESULTS: A total of 4,411 patients were included, the average age at diagnosis was 53 years, 19.7% were diagnosed by mammography screening program and 80.3% derived from any signs or symptoms. Regarding the stages at diagnosis, 6.8% were carcinoma in situ, 36% at early stages (I and IIA), 45% locally advanced (IIB to IIIC), 7.7% metastatic and 3.9% unclassifiable. A 79% were ductal histology, lobular 7.8% and the rest, other types. Of ductal carcinomas, 9.1% were grade I, 54.1% grade II, and 34.6% grade III. Regarding the biological subtypes, 65.7% were luminal, 10.9% luminal Her positive, 8.7% pure Her 2 positive and 14.6% triple negative. CONCLUSION: In the present study, we described the clinical and pathologic features of a group of Mexican women with breast cancer that might reflect a national landscape, and represent the prognostic factors to determine groups of risk and treatment decisions.
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Neoplasias de la Mama/epidemiología , Carcinoma Ductal de Mama/epidemiología , Carcinoma Lobular/epidemiología , Adulto , Distribución por Edad , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/análisis , Biopsia , Neoplasias de la Mama/patología , Carcinoma Ductal de Mama/patología , Carcinoma Intraductal no Infiltrante/epidemiología , Carcinoma Intraductal no Infiltrante/patología , Carcinoma Lobular/patología , Estudios Transversales , Bases de Datos Factuales , Estrógenos , Femenino , Genes erbB-2 , Humanos , México/epidemiología , Persona de Mediana Edad , Metástasis de la Neoplasia , Estadificación de Neoplasias , Neoplasias Hormono-Dependientes/epidemiología , Neoplasias Hormono-Dependientes/patología , Progesterona , Estudios Retrospectivos , Neoplasias de la Mama Triple Negativas/epidemiología , Neoplasias de la Mama Triple Negativas/patologíaRESUMEN
BACKGROUND: The clinical and pathogenetic heterogeneity of Autism Spectrum Disorders (ASD) limits our ability to predict its short- and long-term evolution. Aim of this naturalistic study was to observe the clinical evolution of very young children with ASD for 12 months after first diagnosis, in order to identify those children who might develop a more positive trajectory and understand how a wide range of biological, clinical and familial factors can influence prognosis. METHODS: Ninety-two children were characterized in terms of family history, prenatal and perinatal variables, and clinical conditions. The sample was divided into four subgroups based on the association of 22 biological, clinical and family history variables. Developmental Quotient (DQ), determined using the Psychoeducational Profile Revised (PEP-R), and symptoms severity, measured by means of the Autism Diagnostic Observation Schedule (ADOS), were evaluated at baseline (T0) and after one year (T1), while receiving treatment as usual. Changes in DQ and ADOS between baseline and follow-up and differences in the short-term evolution of the four subgroups were analyzed. RESULTS: At T1, 55.4 % of the children demonstrated some gains either of autistic symptomatology or of developmental skills. Mean ADOS score was 13.63 ± 3.67 at T0 and 10.85 ± 4.10 at T1 and mean DQ was 0.64 ± 0.14 at T0 and 0.66 ± 0.15 at T1. At follow-up, 33.7 % of the children showed an improvement in DQ and 37 % presented a less severe symptomatology, measured by means of ADOS. Overall, 15.2 % of the sample displayed major improvements both on developmental quotient and ADOS severity score; these children presented less EEG abnormalities and familial psychiatric disorders. The four subgroups, based on biological, clinical and familial variables, showed differing trends in terms of evolution. CONCLUSIONS: Categorizing very young children with ASD in terms of biological, clinical and familial variables can be instrumental in predicting short-term evolution. This exploratory study highlights the importance of a precise characterization and thorough analysis of interactions among biological and clinical variables, in order to predict the developmental evolution in children with ASD.
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Trastorno del Espectro Autista/diagnóstico , Evolución Biológica , Diagnóstico Precoz , Factores de Edad , Trastorno del Espectro Autista/epidemiología , Trastorno del Espectro Autista/terapia , Preescolar , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Lactante , Estudios Longitudinales , Masculino , Pruebas Neuropsicológicas , Medición de Riesgo , Muestreo , Índice de Severidad de la Enfermedad , Factores Sexuales , Factores de TiempoRESUMEN
The aim of the present study was to evaluate to what extent the combination of standard histopathological parameters determines the biology of breast cancer and the effect on therapy and prognosis. The Clinical Cancer Registry Regensburg (Bavaria, Germany) included n = 4,480 female patients with primary, non-metastatic (M0) invasive breast cancer diagnosed between 2000 and 2012. Immuno-histochemical analyses, i.e., estrogen receptor (ER), progesterone receptor (PR), HER2, and Ki-67 (4-IHC), defined the tumor biological subtypes Luminal A, Luminal B, HER2-like, and Basal-like. Subtype-related differences in therapies and overall survival (OS) were analyzed using multivariable statistical methods. 4344 patients (97.0 %) could be classified into the four common tumor biological subtypes. The two most frequent entities were Luminal A (48.4 %), Luminal B (24.8 %), HER2-like (17.8 %), and Basal-like subtype (9.0 %). A multivariable Cox regression model showed that the best 7-year OS was seen in Luminal A patients and that OS of Luminal B and HER2-like patients was comparable (HR = 1.59, P < 0.001 versus HR = 1.51, P = 0.03). Lowest OS was seen in patients with Basal-like tumors (HR = 2.18, P < 0.001). In conclusion, the classification of tumor biological subtypes by the ER, PR, HER2, and Ki-67 biomarkers is practical in routine clinical work. Providing that quality assurance of these markers is ensured, this classification is useful for making therapy decisions in the routine clinical management of breast cancer patients.
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Biomarcadores de Tumor , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/metabolismo , Inmunohistoquímica , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/terapia , Toma de Decisiones Clínicas , Estudios de Cohortes , Femenino , Alemania , Humanos , Inmunohistoquímica/métodos , Estimación de Kaplan-Meier , Persona de Mediana Edad , Metástasis de la Neoplasia , Estadificación de Neoplasias , Pronóstico , Sistema de Registros , Factores de Riesgo , Carga TumoralRESUMEN
In cancer, epigenetic states are deregulated and thought to be of significance in cancer development and progression. We explored DNA methylation-based signatures in association with breast cancer subtypes to assess their impact on clinical presentation and patient prognosis. DNA methylation was analyzed using Infinium 450K arrays in 40 tumors and 17 normal breast samples, together with DNA copy number changes and subtype-specific markers by tissue microarrays. The identified methylation signatures were validated against a cohort of 212 tumors annotated for breast cancer subtypes by the PAM50 method (The Cancer Genome Atlas). Selected markers were pyrosequenced in an independent validation cohort of 310 tumors and analyzed with respect to survival, clinical stage and grade. The results demonstrate that DNA methylation patterns linked to the luminal-B subtype are characterized by CpG island promoter methylation events. In contrast, a large fraction of basal-like tumors are characterized by hypomethylation events occurring within the gene body. Based on these hallmark signatures, we defined two DNA methylation-based subtypes, Epi-LumB and Epi-Basal, and show that they are associated with unfavorable clinical parameters and reduced survival. Our data show that distinct mechanisms leading to changes in CpG methylation states are operative in different breast cancer subtypes. Importantly, we show that a few selected proxy markers can be used to detect the distinct DNA methylation-based subtypes thereby providing valuable information on disease prognosis.
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Neoplasias de la Mama/clasificación , Neoplasias de la Mama/genética , Metilación de ADN/genética , Secuencia de Bases , Neoplasias de la Mama/patología , Estudios de Cohortes , Islas de CpG/genética , Variaciones en el Número de Copia de ADN/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Genes Relacionados con las Neoplasias , Genoma Humano , Humanos , Invasividad Neoplásica , Regiones Promotoras Genéticas , Reproducibilidad de los ResultadosRESUMEN
Insights into tumour biology of breast cancer have led the path towards the introduction of targeted treatment approaches; still, breast cancer-related mortality remains relatively high. Efforts in the field of basic research revealed new druggable targets which now await validation within the context of clinical trials. Therefore, questions concerning the optimal design of future studies are becoming even more pertinent. Aspects such as the ideal end point, availability of predictive markers to identify the optimal cohort for drug testing, or potential mechanisms of resistance need to be resolved. An expert panel representing the academic community, the pharmaceutical industry, as well as European Regulatory Authorities met in Vienna, Austria, in November 2012, in order to discuss breast cancer biology, identification of novel biological targets and optimal drug development with the aim of treatment individualization. This article summarizes statements and perspectives provided by the meeting participants.