Germline and Somatic mutations in postmenopausal breast cancer patients.

OBJECTIVES: In breast cancer (BC) patients, the frequency of germline BRCA mutations (gBRCA) may vary according to the ethnic background, age, and family history of cancer. Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) is the second most common somatic mutated gene in BC; however, the association of mutations in both genes with cancer has not been thoroughly investigated. Thus, our aims were to investigate gBRCA mutation frequency in a cohort of postmenopausal Brazilian BC patients and the association of gBRCA1/BRCA2 and PIK3CA somatic mutations. METHODS: Forty-nine postmenopausal (>55 years) and forty-one young (≤35 years) BC patients were included in this study. The postmenopausal group included patients who reported a positive family history of cancer. For these patients, gBRCA1/BRCA2 were sequenced using next-generation sequencing (NGS) or Sanger sequencing. Data for gBRCA in young patients were already available from a previous study. DNA from formalin-fixed, paraffin-embedded (FFPE) tumors was obtained from 27 postmenopausal and 41 young patients for analyzing exons 9 and 20 of PIK3CA. The association between gBRCA1/BRCA2 and somatic mutations in PIK3CA was investigated. RESULTS: The overall frequency of gBRCA1/BRCA2 among the 49 postmenopausal patients was 10.2%. The frequencies of somatic mutations in PIK3CA in the postmenopausal and young patients were 37% and 17%, respectively (ns). The most common PIK3CA mutation was found to be E454A. Nonsense and frameshift mutations, which may counteract the oncogenic potential of PIK3CA were also detected. Regardless of age, 25% of BRCA1/BRCA2 mutation carriers and non-carriers , each, had PIK3CA somatic mutations. CONCLUSIONS: Data obtained indicate that BRCA1/BRCA2 gene testing may be considered for postmenopausal patients with BC who have a family history of cancer. Although some of them are not considered pathogenic, somatic variants of PIK3CA are frequently observed in BC patients, especially in postmenopausal patients.

Germline and Somatic mutations in postmenopausal breast cancer patients

OBJECTIVES: In breast cancer (BC) patients, the frequency of germline BRCA mutations (gBRCA) may vary according to the ethnic background, age, and family history of cancer. Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) is the second most common somatic mutated gene in BC; however, the association of mutations in both genes with cancer has not been thoroughly investigated. Thus, our aims were to investigate gBRCA mutation frequency in a cohort of postmenopausal Brazilian BC patients and the association of gBRCA1/BRCA2 and PIK3CA somatic mutations. METHODS: Forty-nine postmenopausal (>55 years) and forty-one young (≤35 years) BC patients were included in this study. The postmenopausal group included patients who reported a positive family history of cancer. For these patients, gBRCA1/BRCA2 were sequenced using next-generation sequencing (NGS) or Sanger sequencing. Data for gBRCA in young patients were already available from a previous study. DNA from formalin-fixed, paraffin-embedded (FFPE) tumors was obtained from 27 postmenopausal and 41 young patients for analyzing exons 9 and 20 of PIK3CA. The association between gBRCA1/BRCA2 and somatic mutations in PIK3CA was investigated. RESULTS: The overall frequency of gBRCA1/BRCA2 among the 49 postmenopausal patients was 10.2%. The frequencies of somatic mutations in PIK3CA in the postmenopausal and young patients were 37% and 17%, respectively (ns). The most common PIK3CA mutation was found to be E454A. Nonsense and frameshift mutations, which may counteract the oncogenic potential of PIK3CA were also detected. Regardless of age, 25% of BRCA1/BRCA2 mutation carriers and non-carriers , each, had PIK3CA somatic mutations. CONCLUSIONS: Data obtained indicate that BRCA1/BRCA2 gene testing may be considered for postmenopausal patients with BC who have a family history of cancer. Although some of them are not considered pathogenic, somatic variants of PIK3CA are frequently observed in BC patients, especially in postmenopausal patients.

Stromal Cell Signature Associated with Response to Neoadjuvant Chemotherapy in Locally Advanced Breast Cancer.

Breast cancer stromal compartment, may influence responsiveness to chemotherapy. Our aim was to detect a stromal cell signature (using a direct approach of microdissected stromal cells) associated with response to neoadjuvant chemotherapy (neoCT) in locally advanced breast cancer (LABC). The tumor samples were collected from 44 patients with LABC (29 estrogen receptor (ER) positive and 15 ER negative) before the start of any treatment. Neoadjuvant chemotherapy consisted of doxorubicin and cyclophosphamide, followed by paclitaxel. Response was defined as downstaging to maximum ypT1a-b/ypN0. The stromal cells, mainly composed of fibroblast and immune cells, were microdissected from fresh frozen tumor samples and gene expression profile was determined using Agilent SurePrint G3 Human Gene Expression microarrays. Expression levels were compared using MeV (MultiExperiment Viewer) software, applying SAM (significance analysis of microarrays). To classify samples according to tumor response, the order of median based on confidence statements (MedOr) was used, and to identify gene sets correlated with the phenotype downstaging, gene set enrichment analysis (GSEA). Nine patients presented disease downstaging. Eleven sequences (FDR 17) were differentially expressed, all of which (except H2AFJ) more expressed in responsive tumors, including PTCHD1 and genes involved in abnormal cytotoxic T cell physiology, TOX, LY75, and SH2D1A. The following four pairs of markers could correctly classify all tumor samples according to response: PTCHD1/PDXDC2P, LOC100506731/NEURL4, SH2D1A/ENST00000478672, and TOX/H2AFJ. Gene sets correlated with tumor downstaging (FDR < 0.01) were mainly involved in immune response or lymphocyte activation, including CD47, LCK, NCK1, CD24, CD3E, ZAP70, FOXP3, and CD74, among others. In locally advanced breast cancer, stromal cells may present specific features of immune response that may be associated with chemotherapy response.

Somatic mutations in early onset luminal breast cancer.

Breast cancer arising in very young patients may be biologically distinct; however, these tumors have been less well studied. We characterized a group of very young patients (≤ 35 years) for BRCA germline mutation and for somatic mutations in luminal (HER2 negative) breast cancer. Thirteen of 79 unselected very young patients were BRCA1/2 germline mutation carriers. Of the non-BRCA tumors, eight with luminal subtype (HER2 negative) were submitted for whole exome sequencing and integrated with 29 luminal samples from the COSMIC database or previous literature for analysis. We identified C to T single nucleotide variants (SNVs) as the most common base-change. A median of six candidate driver genes was mutated by SNVs in each sample and the most frequently mutated genes were PIK3CA, GATA3, TP53 and MAP2K4. Potential cancer drivers affected in the present non-BRCA tumors include GRHL2, PIK3AP1, CACNA1E, SEMA6D, SMURF2, RSBN1 and MTHFD2. Sixteen out of 37 luminal tumors (43%) harbored SNVs in DNA repair genes, such as ATR, BAP1, ERCC6, FANCD2, FANCL, MLH1, MUTYH, PALB2, POLD1, POLE, RAD9A, RAD51 and TP53, and 54% presented pathogenic mutations (frameshift or nonsense) in at least one gene involved in gene transcription. The differential biology of luminal early-age onset breast cancer needs a deeper genomic investigation.

Germline mutations in BRCA1 and BRCA2 in epithelial ovarian cancer patients in Brazil.

BACKGROUND: Approximately 8-15% epithelial ovarian cancer patients are BRCA1 or BRCA2 germline mutation carriers. Brazilian inhabitants may have peculiar genetic characteristics associated with ethnic diversity, and studies focusing on the entire BRCA1/BRCA2 gene sequencing in Brazilian ovarian cancer patients are still lacking. The aim of this study was to evaluate BRCA1/2 mutations, through entire gene sequencing, in a Brazilian population of women with epithelial ovarian cancer. METHODS: In a cross sectional study performed in one reference centre for cancer treatment in São Paulo, Brazil, 100 patients diagnosed with epithelial ovarian cancer unselected for family history of breast and/or ovarian cancer were included. The complete coding sequence of BRCA1/2 genes was evaluated through Next-Generation or capillary sequencing. Large deletions were investigated through Multiplex Ligation-dependent Probe Amplification (MLPA). RESULTS: Nineteen pathogenic mutations (BRCA1: n = 17 and BRCA2: n = 2) featuring 14 different mutations, including two large deletions in BRCA1 (exon 1-2 deleted and exon 5-7 deleted) were identified. Three mutations were detected more than once (c.3331_3334delCAAG, c.5266dupC and c.4484G > T). Two novel frameshift mutations were identified, one in BRCA1 (c.961_962delTG) and one in BRCA2 (c.1963_1963delC). BRCA1/2 mutations were seen in 35.5% of the patients with first and/or second-degree relatives with breast and/or ovarian cancer. Nineteen variants of uncertain significance (VUS) were detected (BRCA1: n = 2 and BRCA2: n = 17), including five distinct missense variants (BRCA1: c.5348 T > C; BRCA2: c.2350A > G, c.3515C > T, c.7534C > T, and c.8351G > A). CONCLUSIONS: Among epithelial ovarian cancer patients unselected for family history of cancer, 19% were BRCA1/2 germline mutation carriers. Almost ¾ of the BRCA mutations, including two large deletions, were detected only once. Our work emphasizes the need of entire gene sequencing and MLPA screening in Brazil.

Somatic mutations in breast and serous ovarian cancer young patients: a systematic review and meta-analysis.

OBJECTIVE: our aim was to evaluate whether somatic mutations in five genes were associated with an early age at presentation of breast cancer (BC) or serous ovarian cancer (SOC). METHODS: COSMIC database was searched for the five most frequent somatic mutations in BC and SOC. A systematic review of PubMed was performed. Young age for BC and SOC patients was set at ≤ 35 and ≤ 40 years, respectively. Age groups were also classified in < 30 years and every 10 years thereafter. RESULTS: twenty six (1,980 patients, 111 younger) and 16 studies (598, 41 younger), were analyzed for BC and SOC, respectively. In BC, PIK3CA wild type tumor was associated with early onset, not confirmed in binary regression with estrogen receptor (ER) status. In HER2-negative tumors, there was increased frequency of PIK3CA somatic mutation in older age groups; in ER-positive tumors, there was a trend towards an increased frequency of PIK3CA somatic mutation in older age groups. TP53 somatic mutation was described in 20% of tumors from both younger and older patients; PTEN, CDH1 and GATA3 somatic mutation was investigated only in 16 patients and PTEN mutation was detected in one of them. In SOC, TP53 somatic mutation was rather common, detected in more than 50% of tumors, however, more frequently in older patients. CONCLUSION: frequency of somatic mutations in specific genes was not associated with early-onset breast cancer. Although very common in patients with serous ovarian cancer diagnosed at all ages, TP53 mutation was more frequently detected in older women.

Somatic mutations in breast and serous ovarian cancer young patients: a systematic review and meta-analysis / Mutações somáticas em pacientes jovens com câncer de mama e epitelial de ovário: revisão e metanálise

Summary Objective: our aim was to evaluate whether somatic mutations in five genes were associated with an early age at presentation of breast cancer (BC) or serous ovarian cancer (SOC). Methods: COSMIC database was searched for the five most frequent somatic mutations in BC and SOC. A systematic review of PubMed was performed. Young age for BC and SOC patients was set at ≤35 and ≤40 years, respectively. Age groups were also classified in <30years and every 10 years thereafter. Results: twenty six (1,980 patients, 111 younger) and 16 studies (598, 41 younger), were analyzed for BC and SOC, respectively. In BC, PIK3CA wild type tumor was associated with early onset, not confirmed in binary regression with estrogen receptor (ER) status. In HER2-negative tumors, there was increased frequency of PIK3CA somatic mutation in older age groups; in ER-positive tumors, there was a trend towards an increased frequency of PIK3CA somatic mutation in older age groups. TP53 somatic mutation was described in 20% of tumors from both younger and older patients; PTEN, CDH1 and GATA3 somatic mutation was investigated only in 16 patients and PTEN mutation was detected in one of them. In SOC, TP53 somatic mutation was rather common, detected in more than 50% of tumors, however, more frequently in older patients. Conclusion: frequency of somatic mutations in specific genes was not associated with early-onset breast cancer. Although very common in patients with serous ovarian cancer diagnosed at all ages, TP53 mutation was more frequently detected in older women.

Resumo Objetivo: avaliar se mutações somáticas em câncer de mama e seroso de ovário estão associados com pacientes jovens. Métodos: com base no COSMIC, foram selecionados os cinco genes mais frequentes mutados em câncer de mama e seroso de ovário. Em seguida, realizou-se uma revisão sistemática no PubMed. Pacientes jovens foram classificadas com ≤35 anos e ≤40 anos para câncer de mama e seroso de ovário, respectivamente. Classificaram-se também as pacientes em grupos etários de ≤30 anos, separados a cada 10 anos. Resultados: vinte e seis (1.980 pacientes, 111 jovens) e 16 estudos (598, 41 jovens) foram selecionados para câncer de mama e seroso de ovário, respectivamente. Em câncer de mama, pacientes jovens apresentaram baixa frequência de mutações somáticas em PIK3CA. Tumor HER2 negativo foi associado a mutações somáticas em PIK3CA no grupo etário mais avançado, e em tumores ER positivos foi observada uma tendência a essa associação. Mutações somáticas em TP53 foram observadas em 20% dos tumores, em ambos os grupos (≤35 anos vs. ≥35 anos). Mutações somáticas em PTEN, CDH1 e GATA3 foram analisadas em 16 pacientes e apenas uma apresentou mutação em PTEN. Em câncer seroso de ovário, mutações somáticas em TP53 foram detectadas em mais que 50% dos tumores; entretanto, foram mais frequentes em pacientes idosas. Conclusão: a frequência de mutações somáticas nos genes selecionados não foi associada com pacientes jovens. Embora muito comum em pacientes com câncer seroso de ovário, mutações somáticas em TP53 foram mais frequentes em pacientes mais velhas.

Association of family risk and lifestyle/comorbidities in ovarian cancer patients.

OBJECTIVES: to analyze factors that might indicate familial predisposition for ovarian cancer in patients diagnosed with this disease. METHODS: in a prospective single center cohort study at the Institute of Cancer of the State of São Paulo (ICESP), 51 women diagnosed with ovarian cancer were included. Familial predisposition for ovarian cancer was defined as having a higher than 10% chance of having a BRCA1/2 mutation according to the Manchester scoring system, a validated method to assess the likelihood of mutation detection. Each patient was interviewed with a standardized questionnaire on established risk factors for ovarian cancer and other factors that might influence the risk to develop ovarian cancer. Logistic regression analyses were performed to estimate the impact of the evaluated factors on the likelihood of mutation detection, by calculating odds ratios and 95% confidence intervals. RESULTS: seventeen out of 51 patients had a family history of breast and/or ovarian cancer, four patients had a history of breast or endometrial cancer, 11 were diagnosed before the age of 50, and 12 presented a risk of familial predisposition to ovarian cancer higher than 10%. Patients with comorbidities, such as hypertension, diabetes, hormonal disorders, dyslipidemia and psychiatric conditions, presented a lower chance of having a familial predisposition for ovarian cancer (OR: 0.22; 95% CI: 0.06-0.88; p=0.03). CONCLUSION: in this study, having comorbidities was associated with a lower risk of having a familial predisposition for ovarian cancer. Other factors associated with the risk of ovarian cancer did not have an impact on this predisposition.

Association of family risk and lifestyle/comorbidities in ovarian cancer patients / Associação de história familiar e estilo de vida a comorbidades em pacientes com câncer de ovário.

Summary Objectives: to analyze factors that might indicate familial predisposition for ovarian cancer in patients diagnosed with this disease. Methods: in a prospective single center cohort study at the Institute of Cancer of the State of São Paulo (ICESP), 51 women diagnosed with ovarian cancer were included. Familial predisposition for ovarian cancer was defined as having a higher than 10% chance of having a BRCA1/2 mutation according to the Manchester scoring system, a validated method to assess the likelihood of mutation detection. Each patient was interviewed with a standardized questionnaire on established risk factors for ovarian cancer and other factors that might influence the risk to develop ovarian cancer. Logistic regression analyses were performed to estimate the impact of the evaluated factors on the likelihood of mutation detection, by calculating odds ratios and 95% confidence intervals. Results: seventeen out of 51 patients had a family history of breast and/or ovarian cancer, four patients had a history of breast or endometrial cancer, 11 were diagnosed before the age of 50, and 12 presented a risk of familial predisposition to ovarian cancer higher than 10%. Patients with comorbidities, such as hypertension, diabetes, hormonal disorders, dyslipidemia and psychiatric conditions, presented a lower chance of having a familial predisposition for ovarian cancer (OR: 0.22; 95% CI: 0.06-0.88; p=0.03). Conclusion: in this study, having comorbidities was associated with a lower risk of having a familial predisposition for ovarian cancer. Other factors associated with the risk of ovarian cancer did not have an impact on this predisposition. .

Resumo Objetivos: analisar fatores que possam indicar uma predisposição familiar ao câncer de ovário em pacientes com este diagnóstico. Métodos: em estudo de coorte prospectiva realizado no Instituto do Câncer do Estado de São Paulo (ICESP), foram incluídas 51 mulheres diagnosticadas com câncer de ovário entre janeiro de 2009 e dezembro de 2011. Predisposição familiar para câncer de ovário foi definida como um risco maior de 10% de apresentar uma mutação em BRCA1/2, de acordo com o sistema de pontes de Manchester, um método validado para avaliar a probabilidade de detecção de mutação nesses genes. Cada paciente foi entrevistada com um questionário padronizado, abordando fatores de risco para câncer de ovário e outros fatores que pudessem influenciar o risco de desenvolver a doença. O impacto dos fatores avaliados na probabilidade de detecção da mutação foi avaliado com regressões logísticas. Resultados: dezessete das 51 pacientes referiram história familiar de câncer de mama e/ou ovário, quatro pacientes apresentavam antecedente pessoal de câncer de mama ou endométrio, 11 haviam sido diagnosticadas antes dos 50 anos e 12 apresentaram um risco maior que 10% de predisposição familiar a câncer de ovário. Pacientes com comorbidades como hipertensão, diabetes, disfunções hormonais, dislipidemia e distúrbios psiquiátricos apresentaram menor risco de predisposição familiar ao câncer de ovário (OR: 0.22; IC 95%: 0.06-0.88; p=0.03). Conclusão: neste estudo, apresentar alguma comorbidade foi associado a um menor risco de ter uma predisposição familiar ao câncer de ovário. Outros fatores associados ao risco de câncer de ovário não tiveram nenhum impacto sobre esta predisposição. .

Gonocyte development in rats: proliferation, distribution and death revisited.

Spermatogonial stem cells are responsible for the constant production of spermatozoa. These cells differentiate from the gonocytes, but little is known about these cells and their differentiation into spermatogonia. This study analyzed rat gonocyte proliferation, death and distribution as well as their differentiation into spermatogonia. Rat testes were collected at 19 dpc and at 1, 3, 5, 8, 11 and 15 dpp and submitted to apoptosis investigation through morphological analysis and TUNEL, p53 and cleaved caspase 3 labeling. Ki67 and MVH labeling was used to check gonocyte proliferation and quantification, respectively. OCT4 and DBA labeling were used to check gonocyte differentiation. Seminiferous cord length and gonocyte numerical density were measured to check gonocyte distribution along the seminiferous cords. Although a reduction of gonocyte number per testicular section has been observed from 1 to 5 dpp, the total number of these cells did not change. Apoptotic gonocytes were not detected at these ages, suggesting that the reduction in gonocyte number per testicular section was due to their redistribution along the seminiferous cords, which showed continuous growth from 19 dpc to 5 dpp. The first proliferating germ cells were observed at 8 dpp, coinciding with OCT4 upregulation and with the emergence of the first spermatogonia. In conclusion, this study suggests that (a) gonocytes do not die in the first week after birth, but are rather redistributed along the seminiferous cords just before their differentiation into spermatogonia; (b) mitosis resumption and the emergence of the first spermatogonia are coincident with OCT4 upregulation.

Detection of four germ cell markers in rats during testis morphogenesis: differences and similarities with mice.

Germ cells are the only cells capable of transmitting genetic information from generation to generation. Germ cell development has been widely studied in different species. Among mammals, the mouse is the model used in the majority of studies on germ cell differentiation, sex determination and genetics. In the present study, we suggest that the rat is also a very important model for the investigation of the mechanisms of germ cell development. To study rat germ cell development and compare it with that of mouse, the germ cell markers germ cell nuclear antigen 1 (GCNA1), OCT4, mouse vasa homologue (MVH) and specific surface embryonic antigen 1 (SSEA1) were immunolabeled at different phases of embryonic and postnatal development. SSEA1 and GCNA1 were not detected in rat primordial germ cells and fetal gonocytes. GCNA1 was detected postnatally and was present only in leptotene, zygotene and early pachytene spermatocytes. On the other hand, in mice, these markers were detected in germ cells as soon as 11.5 days postcoitum (dpc). MVH was detected in migrating rat primordial germ cells as well as in those that have already colonized the gonads, whereas in mice, MVH is detected only in germ cells that have reached the gonads. In rats, OCT4-positive germ cells were detected from 13 to 17 dpc, but not at 19 dpc or in postnatal testes. This is in contrast with mice that show OCT4 labeling in both embryonic and adult testes. These data suggest that primordial germ cell development in rats and mice shows considerable differences and that the rat may also be an important model to study the embryonic development of germ cells.