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1.
Ann Oncol ; 32(2): 240-249, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33242536

RESUMO

BACKGROUND: The antitumor efficacy of PARP inhibitors (PARPi) for breast cancer patients harboring germline BRCA1/2 (gBRCA1/2) mutations is well established. While PARPi monotherapy was ineffective in patients with metastatic triple negative breast cancer (TNBC) wild type for BRCA1/2, we hypothesized that PARPi may be effective in primary TNBCs without previous chemotherapy exposure. PATIENTS AND METHODS: In the phase II PETREMAC trial, patients with primary TNBC >2 cm received olaparib for up to 10 weeks before chemotherapy. Tumor biopsies collected before and after olaparib underwent targeted DNA sequencing (360 genes) and BRCA1 methylation analyses. In addition, BRCAness (multiplex ligation-dependent probe amplification), PAM50 gene expression, RAD51 foci, tumor-infiltrating lymphocytes (TILs) and PD-L1 analyses were performed on pretreatment samples. RESULTS: The median pretreatment tumor diameter was 60 mm (range 25-112 mm). Eighteen out of 32 patients obtained an objective response (OR) to olaparib (56.3%). Somatic or germline mutations affecting homologous recombination (HR) were observed in 10/18 responders [OR 55.6%, 95% confidence interval (CI) 33.7-75.4] contrasting 1/14 non-responders (OR 7.1%; CI 1.3-31.5, P = 0.008). Among tumors without HR mutations, 6/8 responders versus 3/13 non-responders revealed BRCA1 hypermethylation (P = 0.03). Thus, 16/18 responders (88.9%, CI 67.2-96.9), in contrast to 4/14 non-responders (28.6%, CI 11.7-54.7, P = 0.0008), carried HR mutations and/or BRCA1 methylation. Excluding one gPALB2 and four gBRCA1/2 mutation carriers, 12/14 responders (85.7%, CI 60.1-96.0) versus 3/13 non-responders (23.1%, CI 8.2-50.3, P = 0.002) carried somatic HR mutations and/or BRCA1 methylation. In contrast to BRCAness signature or basal-like subtype, low RAD51 scores, high TIL or high PD-L1 expression all correlated to olaparib response. CONCLUSION: Olaparib yielded a high clinical response rate in treatment-naïve TNBCs revealing HR deficiency, beyond germline HR mutations. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02624973.


Assuntos
Neoplasias de Mama Triplo Negativas , Proteína BRCA1/genética , Humanos , Ftalazinas/uso terapêutico , Piperazinas/uso terapêutico , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/genética
2.
Nat Commun ; 9(1): 2665, 2018 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-29991680

RESUMO

Genomic alterations occurring during melanoma progression and the resulting genomic heterogeneity between metastatic deposits remain incompletely understood. Analyzing 86 metastatic melanoma deposits from 53 patients with whole-exome sequencing (WES), we show a low branch to trunk mutation ratio and little intermetastatic heterogeneity, with driver mutations almost completely shared between lesions. Branch mutations consistent with UV damage indicate that metastases may arise from different subclones in the primary tumor. Selective gain of mutated BRAF alleles occurs as an early event, contrasting whole-genome duplication (WGD) occurring as a late truncal event in about 40% of cases. One patient revealed elevated mutational diversity, probably related to previous chemotherapy and DNA repair defects. In another patient having received radiotherapy toward a lymph node metastasis, we detected a radiotherapy-related mutational signature in two subsequent distant relapses, consistent with secondary metastatic seeding. Our findings add to the understanding of genomic evolution in metastatic melanomas.


Assuntos
Genômica/métodos , Melanoma/genética , Mutação , Neoplasias Cutâneas/genética , Progressão da Doença , Feminino , Heterogeneidade Genética , Genoma Humano/genética , Humanos , Masculino , Melanoma/patologia , Melanoma/terapia , Metástase Neoplásica , Recidiva Local de Neoplasia , Proteínas Proto-Oncogênicas B-raf/genética , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/terapia , Sequenciamento do Exoma/métodos
3.
Breast Cancer Res Treat ; 168(1): 169-178, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29177605

RESUMO

BACKGROUND: Intergroup Exemestane Study (IES) was a randomised study that showed a survival benefit of switching adjuvant endocrine therapy after 2-3 years from tamoxifen to exemestane. This PathIES aimed to assess the role of immunohistochemical (IHC)4 score in determining the relative sensitivity to either tamoxifen or sequential treatment with tamoxifen and exemestane. PATIENTS AND METHODS: Primary tumour samples were available for 1274 patients (27% of IES population). Only patients for whom the IHC4 score could be calculated (based on oestrogen receptor, progesterone receptor, HER2 and Ki67) were included in this analysis (N = 430 patients). The clinical score (C) was based on age, grade, tumour size and nodal status. The association of clinicopathological parameters, IHC4(+C) scores and treatment effect with time to distant recurrence-free survival (TTDR) was assessed in univariable and multivariable Cox regression analyses. A modified clinical score (PathIEscore) (N = 350) was also estimated. RESULTS: Our results confirm the prognostic importance of the original IHC4, alone and in conjunction with clinical scores, but no significant difference with treatment effects was observed. The combined IHC4 + Clinical PathIES score was prognostic for TTDR (P < 0.001) with a hazard ratio (HR) of 5.54 (95% CI 1.29-23.70) for a change from 1st quartile (Q1) to Q1-Q3 and HR of 15.54 (95% CI 3.70-65.24) for a change from Q1 to Q4. CONCLUSION: In the PathIES population, the IHC4 score is useful in predicting long-term relapse in patients who remain disease-free after 2-3 years. This is a first trial to suggest the extending use of IHC4+C score for prognostic indication for patients who have switched endocrine therapies at 2-3 years and who remain disease-free after 2-3 years.


Assuntos
Androstadienos/uso terapêutico , Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/terapia , Recidiva Local de Neoplasia/epidemiologia , Tamoxifeno/uso terapêutico , Idoso , Androstadienos/farmacologia , Antineoplásicos Hormonais/farmacologia , Mama/patologia , Mama/cirurgia , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Quimioterapia Adjuvante/métodos , Intervalo Livre de Doença , Método Duplo-Cego , Resistencia a Medicamentos Antineoplásicos , Feminino , Humanos , Imuno-Histoquímica , Mastectomia , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/prevenção & controle , Prognóstico , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/metabolismo , Tamoxifeno/farmacologia , Fatores de Tempo
4.
Ann Oncol ; 26(9): 1890-1897, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26002610

RESUMO

BACKGROUND: Intergroup Exemestane Study (IES) was a randomised study that showed a survival benefit of switching adjuvant endocrine therapy after 2-3 years from tamoxifen to exemestane. PathIES aimed to assess the potential prognostic and predictive value of ERß1 and ERß2 expression in primary tumours in order to determine benefit in the two treatment arms. PATIENTS AND METHODS: Primary tumour samples were available for 1256 patients (27% IES population). ERß1 and ERß2 expression was dichotomised at the median IHC score (high if ERß1 ≥ 191, ERß2 ≥ 164). Hazard ratios (HRs) were estimated by multivariable Cox proportional hazards models adjusting for clinicopathological factors. Treatment effects with biomarker expressions were determined by interaction tests. Analysis explored effects of markers both as a continuous variable and with dichotomised cut-offs. RESULTS: Neither ERß1 nor ERß2 were associated with disease-free survival (DFS) or overall survival (OS) in the whole cohort. In patients treated with continued tamoxifen, high ERß1 expression compared with low was associated with better DFS [HR = 0.38:95% confidence interval (CI) 0.21-0.68, P = 0.001]. DFS benefit of exemestane over tamoxifen (HR = 0.40:95% CI 0.22-0.70) was found in the low ERß1 subgroup (interaction P = 0.01). No significant difference with treatment was observed for ERß2 expression in either DFS or OS. CONCLUSION: In the PathIES population, exemestane appeared to be superior to tamoxifen among patients with low ERß1 expression but not in those with high ERß1 expression. This is the first trial of its kind to report a parameter potentially predicting benefit of an aromatase inhibitor when compared with tamoxifen and an independent validation is warranted.


Assuntos
Androstadienos/uso terapêutico , Biomarcadores Tumorais/genética , Neoplasias da Mama/tratamento farmacológico , Receptor beta de Estrogênio/genética , Tamoxifeno/uso terapêutico , Idoso , Antineoplásicos/uso terapêutico , Inibidores da Aromatase/uso terapêutico , Neoplasias da Mama/metabolismo , Neoplasias da Mama/mortalidade , Intervalo Livre de Doença , Método Duplo-Cego , Receptor beta de Estrogênio/biossíntese , Feminino , Humanos , Pessoa de Meia-Idade , Prognóstico , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Resultado do Tratamento
5.
Oncogene ; 32(46): 5315-30, 2013 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-23474753

RESUMO

Although new agents are implemented to cancer therapy, we lack fundamental understandings of the mechanisms of chemoresistance, the main obstacle to cure in cancer. Here we review clinical evidence linking molecular defects to drug resistance across different tumour forms and discuss contemporary experimental evidence exploring these mechanisms. Although evidence, in general, is sparse and fragmentary, merging knowledge links drug resistance, and also sensitivity, to defects in functional pathways having a key role in cell growth arrest or death and DNA repair. As these pathways may act in concert, there is a need to explore multiple mechanisms in parallel. Taking advantage of massive parallel sequencing and other novel high-throughput technologies and base research on biological hypotheses, we now have the possibility to characterize functional defects related to these key pathways and to design a new generation of studies identifying the mechanisms controlling resistance to different treatment regimens in different tumour forms.


Assuntos
Antineoplásicos/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias/tratamento farmacológico , Reparo do DNA/genética , Humanos , Neoplasias/genética , Prognóstico
6.
Oncogene ; 31(12): 1533-45, 2012 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-21860418

RESUMO

The wild-type tumor-suppressor gene TP53 encodes several isoforms of the p53 protein. However, while the role of p53 in controlling normal cell cycle progression and tumor suppression is well established, the clinical significance of p53 isoform expression is unknown. A novel bioinformatic analysis of p53 isoform expression in 68 patients with acute myeloid leukemia revealed distinct p53 protein biosignatures correlating with clinical outcome. Furthermore, we show that mutated FLT3, a prognostic marker for short survival in AML, is associated with expression of full-length p53. In contrast, mutated NPM1, a prognostic marker for long-term survival, correlated with p53 isoforms ß and γ expression. In conclusion, p53 biosignatures contain useful information for cancer evaluation and prognostication.


Assuntos
Leucemia Mieloide Aguda/genética , Proteínas Nucleares/genética , Proteína Supressora de Tumor p53/metabolismo , Tirosina Quinase 3 Semelhante a fms/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais , Feminino , Regulação Neoplásica da Expressão Gênica , Genes p53 , Humanos , Leucemia Mieloide Aguda/terapia , Masculino , Pessoa de Meia-Idade , Mutação , Nucleofosmina , Prognóstico , Isoformas de Proteínas/metabolismo
7.
Br J Cancer ; 105(1): 9-12, 2011 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-21673677

RESUMO

BACKGROUND: Glomeruloid microvascular proliferation (GMP), a novel histology-based angiogenesis marker, has been associated with decreased survival in several human cancers. METHODS: In this study, we evaluated the ability of GMP to predict clinical response to neoadjuvant chemotherapy in a series of locally advanced breast cancers (n=112). RESULTS: Presence of GMP (21% of the cases) was significantly associated with high-grade tumours and TP53 mutations in addition to the basal-like and HER2 subtypes of breast cancer as defined by gene expression data. GMP was correlated to a gene expression signature for tumour hypoxia response. The GMP pattern was also significantly associated with lack of treatment response and progressive disease (P=0.004). INTERPRETATION: The findings suggest that GMP might be able to predict the lack of response to neoadjuvant chemotherapy in locally advanced breast cancer. Whether GMP may be an independent predictor compared with other factors including TP53 mutation status and tumour grade needs confirmation in larger studies.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/irrigação sanguínea , Neoplasias da Mama/tratamento farmacológico , Carcinoma Ductal de Mama/irrigação sanguínea , Carcinoma Ductal de Mama/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos , Neovascularização Patológica , Biomarcadores Tumorais/análise , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/patologia , Endotélio Vascular/citologia , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Feminino , Perfilação da Expressão Gênica , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Taxa de Sobrevida , Resultado do Tratamento
8.
Ann Oncol ; 22(10): 2208-15, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21325450

RESUMO

BACKGROUND: We have previously described the essential role of the retinoid-inducible nuclear factor (RINF) during differentiation of hematopoietic cells and suggested its putative involvement in myeloid leukemia and preleukemia. Here, we have investigated whether this gene could have a deregulated expression in malignant tissues compared with their normal tissues of origin and if this potential deregulation could be associated with important clinicopathological parameters. PATIENTS AND METHODS: RINF messenger RNA expression was examined in biopsies from locally advanced breast tumors, metastatic malignant melanomas, and papillary thyroid carcinomas and compared with their paired or nonpaired normal reference samples. Further, the prognostic role of RINF expression was evaluated in locally advanced breast cancer. RESULTS: RINF expression was significantly higher in all tumor forms (primary breast, and thyroid cancers and metastatic melanomas) as compared with normal control tissues (P < 0.001 for each comparison). Importantly, high levels of RINF expression correlated to a poor overall survival in breast cancer (P = 0.013). This finding was confirmed in three independent public microarray datasets (P = 0.043, n = 234; P = 0.016, n = 69; P = 0.001, n = 196) and was independent of tamoxifen therapy. Notably, high levels of RINF was strongly associated with TP53 wild-type status (P = 0.002) possibly indicating that high levels of RINF could substitute for TP53 mutations as an oncogenic mechanism during the malignant development of some cases of breast cancer. CONCLUSIONS: Our data indicate that (i) RINF overexpression is associated with the malignant phenotype in solid tumors and (ii) RINF overexpression represents an independent molecular marker for poor prognosis in breast tumors.


Assuntos
Biomarcadores Tumorais/biossíntese , Neoplasias da Mama/metabolismo , Proteínas de Transporte/biossíntese , Biomarcadores Tumorais/genética , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Carcinoma , Carcinoma Papilar , Proteínas de Transporte/genética , Proteínas de Ligação a DNA , Feminino , Dosagem de Genes , Genes p53 , Humanos , Melanoma/genética , Melanoma/metabolismo , Melanoma/patologia , Mutação , Prognóstico , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Câncer Papilífero da Tireoide , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/metabolismo , Neoplasias da Glândula Tireoide/patologia , Fatores de Transcrição , Proteína Supressora de Tumor p53/biossíntese , Proteína Supressora de Tumor p53/genética
9.
Ann Oncol ; 22(3): 503-514, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20616198

RESUMO

The strategy of using estrogen suppression to treat breast cancer led to the development of aromatase inhibitors, including the third-generation nonsteroidal compounds anastrozole and letrozole, and the steroidal compound exemestane. Aromatase inhibitors potently inhibit aromatase activity and also suppress estrogen levels in plasma and tissue. In clinical studies in postmenopausal women with breast cancer, third-generation aromatase inhibitors were shown superior to tamoxifen for the treatment of metastatic disease. Studies of adjuvant therapy with aromatase inhibitors include (i) head-to-head studies of 5 years of the aromatase inhibitor versus 5 years of tamoxifen monotherapy; (ii) sequential therapy of 2-3 years of tamoxifen followed by an aromatase inhibitor (or the opposite sequence) versus 5 years of tamoxifen monotherapy; (iii) extended therapy with an aromatase inhibitor after 5 years of tamoxifen; and (iv) sequential therapy with an aromatase inhibitor versus aromatase inhibitor monotherapy. Recent results from the Arimidex, Tamoxifen, Alone or in Combination and Breast International Group 1-98 trials advocate using an aromatase inhibitor upfront. This article examines the clinical data with aromatase inhibitors, following a brief summary of their pharmacology.


Assuntos
Antineoplásicos/uso terapêutico , Inibidores da Aromatase/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Aromatase/metabolismo , Quimioterapia Adjuvante , Ensaios Clínicos como Assunto , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Estrogênios/metabolismo , Feminino , Humanos , Metanálise como Assunto , Terapia Neoadjuvante , Recidiva Local de Neoplasia , Resultado do Tratamento
10.
J Steroid Biochem Mol Biol ; 118(4-5): 288-93, 2010 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-19808096

RESUMO

Development of aromatase inhibition and aromatase inhibitors as a therapeutic strategy was initiated through two different pathways. The one pathway went through systematic exploration of aromatase substrate analogues for enzyme inhibitions, subsequently leading to the development of steroidal agents for clinical use. The second involved clinical observation with an unsuccessful anti-epileptic compound named aminoglutethimide, attempting to achieve a "medical adrenalectomy". Endocrine studies on patients treated with aminoglutethimide lead to direct assessment of in vivo aromatase inhibition in patients on treatment, thus identifying a novel therapeutic strategy. As such, both research programs represent different examples of pioneering translational work leading towards a successful therapeutic strategy. Subsequent studies with respect to total aromatase inhibition have led to successful development of more potent strategies. Most importantly, these studies have revealed a correlation between aromatase inhibition and clinical outcome. Ongoing studies exploring tissue estrogen levels as well as gene expression profiles on therapy may further improve this important therapeutic area.


Assuntos
Antineoplásicos Hormonais/uso terapêutico , Inibidores da Aromatase/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Estrogênios/sangue , Estrogênios/metabolismo , Anastrozol , Androstadienos/uso terapêutico , Aromatase/metabolismo , Neoplasias da Mama/metabolismo , Estrogênios/análise , Feminino , Humanos , Letrozol , Nitrilas/uso terapêutico , Pós-Menopausa , Triazóis/uso terapêutico
11.
Br J Cancer ; 101(8): 1253-60, 2009 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-19755984

RESUMO

BACKGROUND: Acquired resistance to endocrine therapy in breast cancer is poorly understood. Characterisation of the molecular response to aromatase inhibitors in breast cancer tissue may provide important information regarding development of oestrogen hypersensitivity. METHODS: We examined the expression levels of nuclear receptor co-regulators, the orphan nuclear receptor liver receptor homologue-1 and HER-2/neu growth factor receptor using real-time RT-PCR before and after 13-16 weeks of primary medical treatment with the aromatase inhibitors anastrozole or letrozole. RESULTS: mRNA expression of the steroid receptor co-activator 1 (SRC-1) and peroxisome-proliferator-activated receptor gamma co-activator-1alpha (PGC-1alpha) was correlated (P=0.002), and both co-activators increased during treatment in the patient group as a whole (P=0.008 and P=0.032, respectively), as well as in the subgroup of patients achieving an objective treatment response (P=0.002 and P=0.006). Although we recorded no significant change in SRC-3/amplified in breast cancer 1 level, the expression correlated positively to the change of SRC-1 (P=0.002). Notably, we recorded an increase in HER-2/neu levels during therapy in the total patient group (18 out of 26; P=0.016), but in particular among responders (15 out of 21; P=0.008). CONCLUSION: Our results show an upregulation of co-activator mRNA and HER-2/neu during treatment with aromatase inhibitors. These mechanisms may represent an early adaption of the breast cancer cells to oestrogen deprivation in vivo.


Assuntos
Inibidores da Aromatase/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Proteínas de Choque Térmico/genética , Histona Acetiltransferases/genética , Receptor ErbB-2/genética , Fatores de Transcrição/genética , Neoplasias da Mama/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Terapia Neoadjuvante , Coativador 1 de Receptor Nuclear , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , RNA Mensageiro/análise , Receptores Citoplasmáticos e Nucleares/genética , Receptores de Estrogênio/análise
12.
J Steroid Biochem Mol Biol ; 117(1-3): 31-41, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19591931

RESUMO

Previous studies have suggested elevated estrogen production in tumour-bearing breast quadrants as well as in breast cancers versus benign tissue. Using highly sensitive assays, we determined breast cancer tissue estrogen concentrations together with plasma and benign tissue estrogen concentrations in each quadrant obtained from mastectomy specimens (34 postmenopausal and 13 premenopausal women). We detected similar concentrations of each of the three major estrogens estradiol (E(2)), estrone (E(1)) and E(1)S in tumour-bearing versus non-tumour-bearing quadrants. Considering malignant tumours, intratumour E(1) levels were reduced in cancer tissue obtained from pre- as well as postmenopausal women independent of tumour ER status (average ratio E(1) cancer: benign tissue of 0.2 and 0.3, respectively; p<0.001 for both groups), suggesting intratumour aromatization to be of minor importance. The most striking finding was a significant (4.1-8.6-fold) increased E(2) concentration in ER positive tumours versus normal tissue (p<0.05 and <0.001 for pre- and postmenopausal patients, respectively), contrasting low E(2) concentrations in ER- tumours (p<0.01 and <0.001 comparing E(2) levels between ER+ and ER- tumours in pre- and postmenopausals, respectively). A possible explanation to our finding is increased ligand receptor binding capacity for E(2) in receptor positive tumours but alternative factors influencing intratumour estrogen disposition cannot be excluded.


Assuntos
Neoplasias da Mama/metabolismo , Estradiol/metabolismo , Estrona/metabolismo , Neoplasias Hormônio-Dependentes/metabolismo , Receptores de Estrogênio/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Mama/metabolismo , Neoplasias da Mama/sangue , Estradiol/sangue , Estrona/análogos & derivados , Estrona/sangue , Feminino , Humanos , Menopausa/sangue , Menopausa/metabolismo , Ciclo Menstrual/sangue , Ciclo Menstrual/metabolismo , Pessoa de Meia-Idade , Neoplasias Hormônio-Dependentes/sangue , Distribuição Tecidual
13.
Eur J Cancer ; 45(4): 527-35, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19062270

RESUMO

While third-generation aromatase inhibitors (anastrozole, letrozole and exemestane) are successfully implemented as adjuvant and first-line therapy for hormone-sensitive breast cancer in postmenopausal women, important questions remain to be addressed. An issue of particular interest is the question about lack of complete cross-resistance between steroidal and non-steroidal compounds. Although the studies reporting this phenomenon in general contain a small number of patients, the findings across the different reports seem consistent. While several potential mechanisms have been suggested, so far we lack scientific proof what mechanisms may be responsible for this finding. Finally, we do not know whether lack of cross-resistance actually signals an improved efficacy for certain compounds or may be due to alternative mechanisms of action. Neither do we know whether some tumours are more sensitive to particular drugs. This paper summarizes clinical findings up to now with respect to lack of cross-resistance and discuss potential mechanisms involved.


Assuntos
Antineoplásicos Hormonais/uso terapêutico , Inibidores da Aromatase/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos , Androgênios/agonistas , Feminino , Humanos
14.
Oncogene ; 27(39): 5182-94, 2008 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-18469852

RESUMO

Chemoresistance represents a major problem in the treatment of many malignancies. Overcoming this obstacle will require improved understanding of the mechanisms responsible for this phenomenon. The progenitor cell marker NG2/melanoma proteoglycan (MPG) is aberrantly expressed by various tumors, but its role in cell death signaling and its potential as a therapeutic target are largely unexplored. We have assessed cytotoxic drug-induced cell death in glioblastoma spheroids from 15 patients, as well as in five cancer cell lines that differ with respect to NG2/MPG expression. The tumors were treated with doxorubicin, etoposide, carboplatin, temodal, cisplatin and tumor necrosis factor (TNF)alpha. High NG2/MPG expression correlated with multidrug resistance mediated by increased activation of alpha3beta1 integrin/PI3K signaling and their downstream targets, promoting cell survival. NG2/MPG knockdown with shRNAs incorporated into lentiviral vectors attenuated beta1 integrin signaling revealing potent antitumor effects and further sensitized neoplastic cells to cytotoxic treatment in vitro and in vivo. Thus, as a novel regulator of the antiapoptotic response, NG2/MPG may represent an effective therapeutic target in several cancer subtypes.


Assuntos
Antígenos/fisiologia , Neoplasias Encefálicas/metabolismo , Resistencia a Medicamentos Antineoplásicos , Glioma/metabolismo , Integrinas/fisiologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteoglicanas/fisiologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Apoptose/fisiologia , Neoplasias Encefálicas/patologia , Ativação Enzimática , Glioma/patologia , Humanos , Fator de Necrose Tumoral alfa/fisiologia
15.
Ann Oncol ; 18 Suppl 8: viii3-7, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17890212

RESUMO

Currently, much effort is being invested in the identification of new, accurate prognostic and predictive factors in breast cancer. Prognostic factors assess the patient's risk of relapse based on indicators such as intrinsic tumor biology and disease stage at diagnosis, and are traditionally used to identify patients who can be spared unnecessary adjuvant therapy based only on the risk of relapse. Lymph node status and tumor size are accepted as well-defined prognostic factors in breast cancer. Predictive factors, in contrast, determine the responsiveness of a particular tumor to a specific treatment. Despite recent advances in the understanding of breast cancer biology and changing practices in disease management, with the exception of hormone receptor status, which predicts responsiveness to endocrine treatment, no predictive factor for response to systemic therapy in breast cancer is widely accepted. While gene expression studies have provided important new information with regard to tumor biology and prognostication, attempts to identify predictive factors have not been successful so far. This article will focus on recent advances in prognostication and prediction, with emphasis on findings from gene expression profiling studies.


Assuntos
Neoplasias da Mama/diagnóstico , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Progressão da Doença , Feminino , Humanos , Valor Preditivo dos Testes , Prognóstico , Medição de Risco
16.
Acta Oncol ; 46(2): 153-64, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17453363

RESUMO

Trastuzumab has shown activity in early breast cancer patients that overexpress HER2. Significant resources have to be allocated to finance this therapy, underlining the need for cost-effectiveness analysis. A model was set up, societal costs were calculated and the discount rate was 3%. Life expectancy data were based on the literature and prolonged according to qualified guess (10% and 20% absolute improvement in overall survival (OS)). The comparator was the FEC(100) regimen. The median additional health care cost per patient treated was 33,597 euros. The yielding cost per life year gained (LYG) was 15,341 euros with a 20% improved OS and 35,947 euros with 10% improved OS. The corresponding net health care cost per quality adjusted life year (QALY) was 19,176 euros and 44,934 euros. Including all resource use the figures were 8148 euros and 30,290 euros per LYG. Sensitivity analyses documented survival gain, price of trastuzumab, production gain and discount rate to be the major factors influencing cost-effectiveness ratio. Trastuzumab is indicated cost effective in Norway.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/economia , Custos de Cuidados de Saúde , Anticorpos Monoclonais Humanizados , Neoplasias da Mama/diagnóstico , Quimioterapia Adjuvante/economia , Análise Custo-Benefício , Feminino , Humanos , Expectativa de Vida , Pessoa de Meia-Idade , Modelos Biológicos , Noruega , Receptor ErbB-2/análise , Trastuzumab
17.
Lancet ; 369(9561): 559-70, 2007 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-17307102

RESUMO

BACKGROUND: Early improvements in disease-free survival have been noted when an aromatase inhibitor is given either instead of or sequentially after tamoxifen in postmenopausal women with oestrogen-receptor-positive early breast cancer. However, little information exists on the long-term effects of aromatase inhibitors after treatment, and whether these early improvements lead to real gains in survival. METHODS: 4724 postmenopausal patients with unilateral invasive, oestrogen-receptor-positive or oestrogen-receptor-unknown breast cancer who were disease-free on 2-3 years of tamoxifen, were randomly assigned to switch to exemestane (n=2352) or to continue tamoxifen (n=2372) for the remainder of a 5-year endocrine treatment period. The primary endpoint was disease-free survival; overall survival was a secondary endpoint. Efficacy analyses were intention-to-treat. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN11883920. RESULTS: After a median follow-up of 55.7 months (range 0-89.7), 809 events contributing to the analysis of disease-free survival had been reported (354 exemestane, 455 tamoxifen); unadjusted hazard ratio 0.76 (95% CI 0.66-0.88, p=0.0001) in favour of exemestane, absolute benefit 3.3% (95% CI 1.6-4.9) by end of treatment (ie, 2.5 years after randomisation). 222 deaths occurred in the exemestane group compared with 261 deaths in the tamoxifen group; unadjusted hazard ratio 0.85 (95% CI 0.71-1.02, p=0.08), 0.83 (0.69-1.00, p=0.05) when 122 patients with oestrogen-receptor-negative disease were excluded. CONCLUSIONS: Our results suggest that early improvements in disease-free survival noted in patients who switch to exemestane after 2-3 years on tamoxifen persist after treatment, and translate into a modest improvement in overall survival.


Assuntos
Androstadienos/uso terapêutico , Inibidores da Aromatase/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Moduladores Seletivos de Receptor Estrogênico/uso terapêutico , Tamoxifeno/uso terapêutico , Idoso , Androstadienos/efeitos adversos , Inibidores da Aromatase/efeitos adversos , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Intervalo Livre de Doença , Esquema de Medicação , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Pós-Menopausa , Moduladores Seletivos de Receptor Estrogênico/efeitos adversos , Análise de Sobrevida , Tamoxifeno/efeitos adversos
18.
Ann Oncol ; 18(8): 1293-306, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17317675

RESUMO

Expanding knowledge, together with implementation of new techniques, has fuelled the area of translational medical research aiming at improving prognostication as well as prediction in cancer therapy. At the same time, new discoveries have revealed a biological complexity we were unaware of only a decade ago. Thus, we are faced with novel challenges with respect to how we may explore issues such as prognostication and predict drug resistance in vivo. While microarray analysis exploring expression of thousands of genes in concert represents a major methodological advancement, discoveries such as the finding of different mechanisms of epigenetic silencing, intronic mutations, that most gene transcripts in the human genome are subject to alternative splicing and that hypersplicing seems to be a tumour-related phenomenon, exemplifies a complex pathology that may not be explored with use of single analytical methods only. This paper discusses clinical settings for studying drug resistance in vivo together with a discussion of contemporary biology in this field. Notably, each individual parameter which has been found correlated to drug resistance in vivo so far represents either a direct drug target or a factor involved in DNA repair or apoptosis. On the basis of these findings, we suggest drug resistance may be explored on the basis of upfront biological hypotheses.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/mortalidade , Resistencia a Medicamentos Antineoplásicos/genética , Perfilação da Expressão Gênica/tendências , Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Feminino , Humanos , Prognóstico
19.
Int J Gynecol Cancer ; 16 Suppl 2: 518-20, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17010062

RESUMO

Bone loss may be a potential side effect of implementing aromatase inhibitors in the adjuvant setting. Current evidence suggests a minor bone loss during treatment with the steroidal aromatase inhibitor exemestane compared to placebo and a nonsignificant increase in fracture rate during treatment with exemestane when compared to tamoxifen. Such a difference could be due to the bone-sparing effects of tamoxifen. For the nonsteroidal inhibitors letrozole and anastrozole, the MA17 study revealed a nonsignificant increase in fracture rate for letrozole compared to placebo. In contrast, both anastrozole and letrozole were found to significantly increase fracture rate compared to tamoxifen when administered as monotherapy or given sequentially. While an increased fracture rate may have detrimental effects, evidence suggests that enhanced bone loss may be preventable through careful bone mineral density (BMD) assessment and treatment with bisphosphonates.


Assuntos
Antineoplásicos Hormonais/efeitos adversos , Inibidores da Aromatase/efeitos adversos , Densidade Óssea/efeitos dos fármacos , Neoplasias da Mama/tratamento farmacológico , Fraturas Ósseas/induzido quimicamente , Tamoxifeno/efeitos adversos , Anastrozol , Feminino , Fraturas Ósseas/prevenção & controle , Humanos , Letrozol , Nitrilas/efeitos adversos , Pós-Menopausa , Triazóis/efeitos adversos
20.
Eur J Cancer ; 42(17): 2968-75, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16963261

RESUMO

Aromatase inhibitors improve relapse-free survival in early breast cancer, but there is concern about possible detrimental effects on bone mineral density (BMD) and plasma lipids. This paper presents the results of a 2-year study evaluating the effects of exemestane versus placebo on BMD, bone markers, plasma lipids and coagulation factors, including a 1-year follow-up after termination of treatment in 147 patients. During treatment, the mean annual rate of loss of BMD in the lumbar spine was 2.17% in the exemestane group versus 1.84% in the placebo group (n.s.) and 2.72% versus 1.48%, respectively, in the femoral neck (P=0.024). A loss of BMD above that expected in both arms of this study could be due to low vitamin D status (88% of all patients had vitamin D levels <30 ng/ml). The changes observed with exemestane were partially reversed during a 1-year follow-up, with no significant difference between the two arms. Similarly, the moderate decrease in high-density lipoprotein (HDL)-cholesterol was reversed. The bone marker values decreased, although a difference at 6 months of follow-up was still recorded, in particular for the markers of bone synthesis.


Assuntos
Androstadienos/efeitos adversos , Inibidores da Aromatase/efeitos adversos , Densidade Óssea/efeitos dos fármacos , Neoplasias da Mama/tratamento farmacológico , Biomarcadores/metabolismo , Fatores de Coagulação Sanguínea/metabolismo , Remodelação Óssea , Osso e Ossos/metabolismo , Neoplasias da Mama/metabolismo , Feminino , Seguimentos , Hormônios Esteroides Gonadais/sangue , Homocisteína/sangue , Humanos , Lipídeos/sangue , Pessoa de Meia-Idade , Pós-Menopausa , Vitamina D/sangue , Suspensão de Tratamento
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