Zhi-Ming Shao

Breast cancer subpopulation with high risk of internal mammary lymph nodes metastasis: analysis of 2,269 Chinese breast cancer patients treated with extended radical mastectomy

PurposeThe selective treatment of internal mammary lymph nodes (IMNs) in breast cancer is controversial. The purpose of this research was to determine the subpopulation patients with high risk of internal mammary lymph nodes metastasis who received extended radical mastectomy without any preoperative treatment from 1956 to 2003 in China.Patients and methods1,679 Chinese patients were underwent extended radical mastectomy (ERM) between 1956 and 2003. Four individual variables were selected (tumor site, tumor size, the number of ALNs involvement, patient age),then classified by following standards: tumor site(lateral, central, medial),tumor size(T1:≤2xa0cm; T2:2xa0<xa0Txa0≤xa05xa0cm, T3:>5xa0cm), ALNs(0,1–3,4–6, ≥7), age(≤35xa0y, 36–50xa0y, >50xa0y). Chi-square and binary logistic regression were used to analysis relationship of these variable and IMMs.ResultsThe four individual variables were significantly associated with IMNs metastasis using univariate analysis. However, three individual variables except for tumor size independently impact the IMNs metastasis using multivariate analysis. The incidence of IMNs metastasis in patients with 4–6 and ≥7 positive ALNs was 28.1%, 41.5%. Within subgroup patients with medial tumor and positive ALNs, the incidence of IMNs metastasis was 23.6% for patients with 1–3 positive ALNs, and 47.5% for 4–6 positive ALNs, 38.7% for patients with ≥7 positive ALNs. The incidence of IMNs metastasis was 25.4% for patients with T3 tumor and younger than 35xa0y.ConclusionPatients with following conditions had high risk of IMNS metastasis: (1) patients with 4 or more positive ALNs. (2) patients with medial tumor and positive ALNs.(3) patients with T3 tumor and younger than 35xa0y. (4) patients with T2 tumor and positive ALNs.(5) patients with T2 tumor and medial tumor .The incidences of IMNS metastasis for those patients were more than 20%.

The prevalence of PALB2 germline mutations in BRCA1/BRCA2 negative Chinese women with early onset breast cancer or affected relatives

PALB2 has been recently identified as breast cancer susceptibility gene in western populations. To investigate the contribution of PALB2 mutations to Chinese non-BRCA1/BRCA2 hereditary breast cancer, we screened all coding exons and intron-exon boundaries of PALB2 in 360 Chinese women with early-onset breast cancer or affected relatives from five breast disease clinical centers in China by utilizing PCR-DHPLC and DNA sequencing analysis. Some genetic variants identified in the cases were then studied in 864 normal controls with no personal or family history of breast cancer. Two protein-truncating PALB2 mutations, 751C>T and 1050_1051delAAinsTCT, were identified in three separate families, and 751C>T was a recurrent mutation. Neither of them, however, were present in the controls (Pxa0=xa00.025). All the truncating mutations occured in exon 4 of PALB2, and there were still three unclassified variants were detected in the same fragment. We found that exon 4 accounted for 44.1% (15/34) of the person-times carrying with any variant in our study. PALB2 mutations were responsible for approximately 1% of Chinese women with early-onset breast cancer and affected relatives. Our results suggested that a detection of exon 4 before the assay of the whole PALB2 gene might be a cost-effective approach to the screening of Chinese population.

Tumor Associated Macrophage × Cancer Cell Hybrids May Acquire Cancer Stem Cell Properties in Breast Cancer

Breast cancer is one of the most frequently diagnosed cancers among women, and metastasis makes it lethal. Tumor-associated macrophages (TAMs) that acquire an alternatively activated macrophage (M2) phenotype may promote metastasis. However, the underlying mechanisms are still elusive. Here, we examined how TAMs interact with breast cancer cells to promote metastasis. Immunohistochemistry was used to examine the expression of the M2-specific antigen CD163 in paraffin-embedded mammary carcinoma blocks to explore fusion events in breast cancer patients. U937 cells were used as a substitute for human monocytes, and these cells differentiated into M2 macrophages following phorbol 12-myristate 13-acetate (PMA) and M-CSF stimulation. M2 macrophages and the breast cancer cell lines MCF-7 and MDA-MB-231 fused in the presence of 50% polyethylene glycol. Hybrids were isolated by fluorescence-activated cell sorting, and the relevant cell biological properties were compared with their parental counterparts. Breast cancer stem cell (BCSC)-related markers were quantified by immunofluorescence staining, RT-PCR, quantitative RT-PCR and/or western blotting. The tumor-initiating and metastatic capacities of the hybrids and their parental counterparts were assessed in NOD/SCID mice. We found that the CD163 expression rate in breast cancer tissues varied significantly and correlated with estrogen receptor status (p<0.05). The fusion efficiency of either breast cancer cell line with M2 macrophages ranged from 1.81 to 6.47% in the presence of PEG, and no significant difference was observed between the breast cancer cell lines used (p>0.05). Characterization of the fusion hybrids revealed a more aggressive phenotype, including increased migration, invasion and tumorigenicity, but reduced proliferative ability, compared with the parental lines. The hybrids also gained a CD44+CD24−/low phenotype and over-expressed epithelial-mesenchymal transition-associated genes. These results indicate that TAMs may promote breast cancer metastasis through cell fusion, and the hybrids may gain a BCSC phenotype.

Polymorphism rs4919510:C>G in Mature Sequence of Human MicroRNA-608 Contributes to the Risk of HER2-Positive Breast Cancer but Not Other Subtypes

Background A few polymorphisms are located in the mature microRNA sequences. Such polymorphisms could directly affect the binding of microRNA to hundreds of target mRNAs. It remains unknown whether rs4919510:C>G located in the mature miR-608 alters breast cancer susceptibility. Methods The association of rs4919510:C>G with risk and pathologic features of breast cancer were investigated in two independent case-control studies, the first set including 1,138 sporadic breast cancer patients (including 927 invasive ductal carcinoma patients, 777 of them with known subtypes: 496 luminal-like, 133 HER2-positive, and 148 triple-negative) and 1,434 community-based controls, and the second set including 294 familial/early-onset breast cancer patients and 500 hospital-based cancer-free controls. Odds ratios (ORs) were estimated by logistic regression. Predicted targets of miR-608 and complementary sequences containing rs4919510:C>G were surveyed to reveal potential pathological mechanism. Results In the first set, although rs4919510:C>G was unrelated to breast cancer in general patients, variant genotypes (CG/GG) were specifically associated with increased risk of HER2-positive subtype (Adjusted ORu200a=u200a1.97, 95% CI, 1.34−2.90 in the recessive model). Variant G-allele was the risk allele with OR of 1.62 (95% CI, 1.23−2.15). Patients carrying GG-genotype also had larger HER2-positive tumors (P for Kruskal-Wallis testu200a=u200a0.006). The relationship between rs4919510:C>G and risk of HER2-positive subgroup was validated in the second set (Bonferroni corrected Pu200a=u200a0.06). The adjusted combined OR (total 164 HER2-positive cases) in the recessive model was 1.97 (95% CI, 1.43−2.72) for GG genotype (corrected Pu200a=u200a1.1×10−4). Bioinformatic analysis indicated that, HSF1, which is required for HER2-induced tumorigenesis, might be a target of miR-608. The minimum free-energy of ancestral-miR-608 (C-allele) binding to HSF1 is −35.9 kcal/mol, while that of variant-form (G-allele) is −31.5 kcal/mol, indicating a lower affinity of variant-miR-608 to HSF1 mRNA. Conclusion rs4919510:C>G in mature miR-608 may influence HER2-positive breast cancer risk and tumor proliferation.

Mutation analysis of BRIP1/BACH1 in BRCA1/BRCA2 negative Chinese women with early onset breast cancer or affected relatives

The proper interaction between BRIP1/BACH1 and BRCA1 protein has been found to be crucial for BRCA1-mediated DNA double-strand break repair and BRIP1/BACH1 mutations were estimated to confer a relative risk for breast cancer of 2.0 in western populations. In Chinese population, BRCA1 mutations could explain a relatively large proportion of inherited breast cancer cases in comparison with BRCA2 mutations, which probably deduced a hypothesis that those genes involved in BRCA1-mediated DNA repair pathway might play a more significant role in the etiology of Chinese breast cancer. To investigate the contribution of BRIP1/BACH1 mutations to the predisposition of Chinese non-BRCA1/BRCA2 hereditary breast cancer, we screened all the coding exons and adjacent intronic splice junction regions of BRIP1/BACH1 in 357 Chinese women with early-onset breast cancer or affected relatives from five different breast disease clinical centers in China, using PCR-DHPLC and DNA sequencing analysis. Some genetic variants identified in the cases were then studied in 864 normal controls with no personal or family history of breast cancer. We found no protein-truncated mutations in our population, while a novel recurrent non-synonymous variant, Q944E, was detected in two independent families in contrast with none in the controls, interestingly, this alteration occurs in the BRCA1 binding domain of the BACH1 protein. Then a further study performed on the two mutation positive families revealed the partial co-segregation of this mutation allele with cancer. The novel alteration Q944E identified in our study possibly represents a rare disease-related allele, nevertheless functional analysis is still warranted to resolve the ability of this altered BACH1 protein to bind BRCA1. Altogether, the results of our study indicated that germline mutations in BRIP1/BACH were extremely rare in Chinese population and there was no evidence for the recommendation of BRIP1/BACH1 for genetic testing in Chinese.

Outcome of Pure Mucinous Breast Carcinoma Compared to Infiltrating Ductal Carcinoma: A Population-based Study from China

PurposePure mucinous breast carcinoma (PMBC) is a rare pathologic finding. Few studies have addressed the biologic features of PMBC and prognostic factors among patients with this disease. We performed a study to compare PMBC and invasive ductal carcinoma (IDC) by means of a large database to reliably assess the biologic phenotype and clinical behavior of PMBC.MethodsA total of 2,511 patients who met the inclusion criteria were identified from 1999 to 2010; 2,202 patients had pure IDC and 309 had PMBC. Clinical and biologic features, overall survival, and recurrence/metastasis-free survival (RFS) were compared for both groups.ResultsPMBC had favorable characteristics including smaller size, lower rates of lymph node positivity, lower stage, higher expression of hormone receptors, and less HER2 overexpression. Patients with PMBC had better 10-year RFS (71xa0%) than patients with IDC (64xa0%). Multivariate analysis revealed that node status and tumor, node, metastasis system (TNM) stage were statistically significant prognostic factors for survival. RFS curves stratified for node status revealed a highly significant difference between node negative and node positive patients. Additionally, patients with PMBC underwent breast-conserving surgery (BCS) more frequently than patients with IDC, and the 5-year overall survival rate of the BCS group was not significantly different from the total mastectomy group.ConclusionsPMBC in Chinese women showed less aggressive behavior and had a better prognosis than IDC, and this favorable outcome was maintained after 10xa0years. Node status and TNM stage appeared to be the most significant predictors of worse prognosis. BCS should be preferred over mastectomy in the treatment of early-stage PMBC.

RAD50 and NBS1 are not likely to be susceptibility genes in Chinese non-BRCA1/2 hereditary breast cancer

Deleterious mutations in several genes that are involved in repair of damage to DNA have been associated with an increased risk of breast cancer. Recent studies have shown sequence variants in two such genes, RAD50 and NBS1, which can be predisposed to breast cancer. The aim of this study is to elucidate the contribution of RAD50 and NBS1 germline mutations to the etiology of non-BRCA1/2 hereditary breast cancer in China. We conducted a mutational analysis of RAD50 and NBS1 in genomic DNA from 384 Chinese women with early-onset breast cancer and/or affected relatives. All the coding exons and adjacent intronic splice junction rejoins of RAD50 and NBS1 were screened using PCR-DHPLC and DNA sequencing analysis. Among all cases, no obviously deleterious mutations were observed in RAD50; one synonymous change c.102G>A at codon 34 and one single nucleotide polymorphism IVS9xa0+xa019C>T were identified in NBS1. Furthermore, there was no remarkable difference in the allele frequency of NBS1 c.553G>C (E185Q) between cases (172/384) and controls (182/420). Our results exclude the possible role of RAD50 and NBS1 in familial breast cancer predisposition in Chinese women, and there is no evidence for the recommendation of RAD50 and NBS1 for genetic testing in China.

Prognostic and predictive value of Phospho-p44/42 and pAKT in HER2-positive locally advanced breast cancer patients treated with anthracycline-based neoadjuvant chemotherapy.

BackgroundTo evaluate the predictive and prognostic value of various molecular factors associated with the Ras/MAPK and PI3K/Akt signaling pathways in HER2-positive locally advanced breast cancer patients treated with anthracycline-based neoadjuvant chemotherapy (NAC).MethodsA total of 113 patients were recruited in this retrospective study. Core needle biopsies and excision samples were assessed through immunohistochemistry for various biomarkers, including IGF-1R, Phospho-p44/42, Ki67, pAKT, PTEN, p27, and cyclinD1. The changes in these biomarkers after NAC and their predictive and prognostic values were investigated.ResultsSignificant decreases in Ki67, Phospho-p44/42, and pAKT expression were observed after treatment (30.7% vs. 18.1%, 36.4% vs. 18.9%, and 35.1% vs. 16.4%, respectively). The decreases in Phospho-p44/42, pAKT, and Ki67 expression were strongly associated with the response to anthracycline treatment (Pu2009=u20090.027, Pu2009=u20090.031, and Pu2009=u20090.008, respectively). In a multivariate survival analysis, Phospho-p44/42 expression after neoadjuvant chemotherapy and lymph node status were significant independent prognostic factors of both relapse-free survival and overall survival.ConclusionsReductions in Ki-67, Phospho-p44/42, and pAKT expression are related to the clinical response to anthracycline-based NAC in HER2-positive breast cancer patients. High pAKT expression prior to NAC had a better clinical response. Phospho-p44/42 expression and lymph node status after NAC could be useful for determining relapse-free survival and overall survival.

Genetic variants in oxidative stress-related genes predict chemoresistance in primary breast cancer: a prospective observational study and validation

Chemotherapy response in patients with primary breast cancer is difficult to predict and the role of host genetic factors has not been thoroughly investigated. We hypothesized that polymorphisms in oxidative stress (OS)-related genes, including estrogen-quinone metabolizing enzymes NQO2 and GSTM1-5, may influence disease progression and treatment response. In this prospective observational study, nineteen polymorphisms tagging known variations in candidate genes were genotyped and analyzed in 806 patients with primary breast cancer. Three functional polymorphisms, which were shown to affect gene expression levels in experiments in vitro and ex vivo, modified the effect of chemotherapy on disease-free survival. There were significant interactions between chemotherapy and individual polymorphisms or combined genotypes (designated as genetic score). Patients harboring high genetic score had a 75% reduction in the hazard of disease progression compared with patients with low genetic score when no chemotherapy was administered (HR = 0.25, 95% CI: 0.10-0.63, P = 0.005); however, they received much less survival benefit from adjuvant chemotherapy compared with patients with low genetic score when chemotherapy was administered (HR = 4.60 for interaction, 95% CI: 1.63-13.3, P = 0.004). These findings were validated in another population (n = 339). In conclusion, germline polymorphisms in OS-related genes affect chemotherapy sensitivity in breast cancer patients. Although reduced OS levels might prevent breast cancer progression, they probably compromise the effectiveness of adjuvant chemotherapy. Our findings also indicate that host-related factors must be considered for individualized chemotherapy.

The associations between two polymorphisms in the interleukin-10 gene promoter and breast cancer risk

The association between single-nucleotide polymorphisms (SNPs) in the interleukin-10 (IL-10) gene promoter and breast cancer risk is still ambiguous. We here performed a meta-analysis based on the evidence currently available from the literature to make a more precise estimation of the relationship between two genetic variants in the IL-10 gene promoter, −1082Axa0>xa0G (rs1800896) and −592Cxa0>xa0A (rs1800872), and breast cancer. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the corresponding strengths of association under the codominant, dominant, and recessive models. A total of ten studies (4,181 cases and 4,384 controls) were eligible for meta-analysis. There were six studies with 3,032 cases and 3,190 controls for rs1800872, and eight studies with 1,636 cases and 1,670 controls for rs1800896. Meta-analysis showed that neither of the two polymorphisms had any association with increased breast cancer risk (for rs1800896: ORxa0=xa01.060, 95% CIxa0=xa00.785–1.432 in the dominant model, and ORxa0=xa01.152, 95% CIxa0=xa00.958–1.386 in the recessive model; and for rs1800872: ORxa0=xa00.952, 95% CIxa0=xa00.859–1.056 in the dominant model, and ORxa0=xa00.892, 95% CIxa0=xa00.741–1.072 in the recessive model). The results did not change when the analyses were restricted in Caucasians, or in the studies fulfilling Hardy–Weinberg equilibrium, or according to source of controls. In outlier analysis, no individual study affected the overall OR dominantly, since omission of any single study made no material huge difference. In conclusion, the present meta-analysis suggests a lack of association between the two SNPs (rs1800896 and rs1800872) in the IL-10 gene promoter and breast cancer risk. Further studies, either with larger sample size or regarding other SNPs/haplotypes within the IL-10 gene, are needed to clarify the role of IL-10 in breast carcinogenesis.