Sporadic Invasive Breast Carcinomas Research Articles

Expression and Clinical Significance of Androgen Receptor in Triple-Negative Breast Cancer.

Background: Triple-negative breast cancer (TNBC) has a poor prognosis because of frequent recurrence. Androgen receptor (AR) is involved in the pathogenesis of breast cancer, but its role is not clearly defined. The aim of this study was to explore the expression of AR and its relationship with clinicopathologic features in TNBC. Methods: This study investigated 1036 cases of sporadic invasive breast carcinoma. Immunohistochemical assays were performed to determine the expression of AR in 190 TNBC samples. The relationships between AR expression and clinicopathologic data and prognosis were analyzed. Results: In 190 TNBC cases, the prognosis of AR-positive patients was significantly better (p = 0.019, log-rank) than AR-negative patients, and in multivariate analysis, AR expression was an independent indicator of good prognosis (p = 0.039, hazard ratio = 0.36). In patients with disease relapse, AR positivity was significantly correlated with better prognosis (p = 0.034, log-rank). Conclusions: AR expression may be useful as a subclassification marker for prognosis in TNBC.

BRCA-mutated Invasive Breast Carcinomas: Immunohistochemical Analysis of Insulin-like Growth Factor II mRNA-binding Protein (IMP3), Cytokeratin 8/18, and Cytokeratin 14.

To evaluate the expression of insulin-like growth factor II mRNA-binding protein (IMP3), CK8/18, and CK14 in BRCA mutated and sporadic invasive breast carcinoma. Immunohistochemistry for IMP3, CK8/18, and CK14 was performed on 39 cases of invasive breast carcinomas with BRCA mutation (24 BRCA1, 14 BRCA2, and 1 dual BRCA1/BRCA2) and 54 cases of sporadic invasive breast carcinomas. The relationship between the IMP3, CK8/18, and CK14 and the tumor grade and molecular phenotypes were analyzed. IMP3, CK8/18, and CK14 positivity were present in 20 (51%), 22 (56%), and 14 (36%) of 39 BRCA-mutated breast carcinomas, and 11 (20%), 53 (98%), and 24 (44%) of 54 sporadic breast carcinomas respectively. The rates of IMP3 expression and absence of CK8/18 (44% versus 2%) in BRCA-mutated breast carcinomas was significantly higher than the sporadic breast carcinomas (p = 0.002 and p < 0.001). No significant difference was observed for CK14 among the two groups (p = 0.408). No significant difference was observed among BRCA1-related and BRCA2-related breast carcinomas in the immunoprofile for IMP3, CK8/18, and CK14. No significant correlation was identified between the expression of IMP3 and CK8/18 and the tumor grade in both BRCA-mutated and sporadic breast carcinomas (p > 0.05). In cases with luminal A and B phenotypes, the rates of expression of IMP3 and loss of CK8/18 were significantly higher in BRCA-mutated as compared to sporadic breast carcinoma (p < 0.001). In cases with basal-like phenotype, the absence of CK8/18 expression was significantly higher in BRCA-mutated breast carcinomas (54% versus 0%, p = 0.001), while no difference was observed for IMP3 expression (p = 0.435). Regardless of mutation type, histologic grade, or molecular phenotype, the absence of CK8/18 expression and presence of IMP3 expression are seen at much higher rate in BRCA mutated breast carcinomas.

O3-4-1 - Expression and Clinical Significance of Androgen Receptor in Triple-Negative Breast Cancer

Background: Triple-negative breast cancer (TNBC), a subtype of breast tumor with ER negative, PR negative, and HER2 negative, shows a poor prognosis because of a frequent recurrence. Androgen receptor (AR) is involved in the pathogenesis of breast cancer, but its role is not clearly defined. This study was to explore the expression of AR and its relationship with clinicopathologic parameters in TNBC.Methods: This study investigated a consecutive series of 1036 cases of sporadic invasive breast carcinoma. Immunohistological assays were performed to determine the expression of AR in 190 of TNBC. The relationships between AR expression and clinicopathologic data and prognosis were analyzed.Results: Of informative 1036 breast cancer cases, triple-negative phenotype was 190 (18.3%). TNBC patients experienced a poorer prognosis in comparison to non-TNBC patients (p < 0.001, log-rank). The cases with AR expression was found in 56 patients (29.5%) in TNBC. In 190 TNBC cases, the prognosis of AR-negative patients was significantly poor (p = 0.019, log-rank), and it was an independent indicator of a poor prognosis by multivariate analyses (p = 0.039).Conclusions: AR might be a prognostic marker and possible endocrine target for therapy in patients with TNBC.

Abstract P5-01-06: Differences in FGF1 and FGFR2 expression in BRCA1-associated, BRCA2-associated, and sporadic breast carcinomas

Abstract Introduction. In contrast to BRCA1-associated breast cancer, a distinctive phenotype for BRCA2-associated carcinomas has not been identified yet as there is no clear distinction between BRCA2- and non-BRCA mutation related or sporadic carcinomas. Recently, studies suggest overexpression of fibroblast growth factor 1 (FGF1) and fibroblast growth factor receptor 2 (FGFR2) in BRCA2 related cancers. The aim of the study was therefore to investigate whether there is differential expression of FGF1 and/or FGFR2 between BRCA2 related and sporadic and BRCA1 related cancers. This would reveal the usefulness of FGF1 and FGFR2 immunohistochemistry in daily pathology practise. Method. Invasive breast carcinomas of 33 BRCA1 and 22 BRCA2 germline mutation carriers and a tissue microarray containing 104 sporadic invasive breast carcinomas were immunohistochemically stained for FGF1, FGFR2, estrogen receptor (ER), progesterone receptor (PR), HER2, epidermal growth factor receptor 1 (EGFR), cytokeratin (CK) 5/6 and CK14. Results. FGFR2 expression was seen in 68.2% and 79.0% of BRCA2-associated and sporadic carcinomas respectively, in contrast to 22.6% of BRCA1-associated tumors (p = 0.000). FGF1 expression was seen in 72.7% of BRCA2-associated carcinomas and in 45.2% and 41.8% in BRCA1-associated and sporadic carcinomas, respectively (p = 0.032). Conclusion. FGFR2 expression differs significantly between BRCA1- and BRCA2 associated breast carcinomas but not between BRCA2 and sporadic cancers. FGF1 expression differs significantly between BRCA2-associated and sporadic carcinomas and could be used as a BRCA2-specific biomarker. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-01-06.

Immunohistochemical study of PTEN and phosphorylated mTOR proteins in familial and sporadic invasive breast carcinomas

Loss of phosphatase and tensin homologue (PTEN) leads to activation of several kinases, including mammalian target of rapamycin (mTOR), which promotes cell cycle progression. The aim was to study the expression of PTEN and phosphorylated (p)-mTOR in familial and sporadic invasive breast carcinomas and their relation to clinicopathological features, molecular indices (Wnt1) and patients' survival. PTEN and p-mTOR were detected immunohistochemically in 215 sections of invasive breast carcinomas (112 with a familial history of breast cancer). Image analysis was used and univariate and multivariate analyses employed for statistical evaluation of results. PTEN was detected in the nucleus (73.5%) and p-mTOR in the cytoplasm (44.2%) of cancer cells. Loss of PTEN protein was more frequently detected in women with a familial history of breast cancer (72%) (P < 0.0001), while its expression was negatively correlated with Wnt1, in total (P = 0.049). p-mTOR showed a positive association with lymph node status (P = 0.010) and was found to have a negative impact on patients' overall survival (P = 0.016). Loss of PTEN protein expression appears to occur more frequently in women with a family history of breast cancer, whereas activation of mTOR protein seems to be related to a more aggressive phenotype.

Genomic Instability Within Tumor Stroma and Clinicopathological Characteristics of Sporadic Primary Invasive Breast Carcinoma

That genomic alterations occur in both the epithelium and stroma of sporadic breast cancers has been documented by several groups. However, whether these microenvironmental alterations relate to clinicopathological features is unknown. To analyze the relationship between stromal genomic alterations and presenting clinicopathological features in sporadic breast cancer. A retrospective cross-sectional analysis of DNA from the epithelium and stroma of 220 primary sporadic invasive breast carcinomas for global genomic alterations manifested by loss of heterozygosity/allelic imbalance with 386 microsatellite markers. Data were collected from October 2003 through June 2006 from samples at Brigham and Women's Hospital, Boston, Mass. Association of the loss of heterozygosity/allelic imbalance, in both the stroma and epithelium, with presenting clinicopathological features, such as tumor grade, expression status of estrogen receptor and progesterone receptor, human epidermal growth factor receptor 2, clinical stage, and regional lymph node metastasis status. Associations were assessed in regression models and tested with Fisher exact test. Bonferroni correction was applied to P values, with significance set at P<.0022. We found significant associations between loss of heterozygosity/allelic imbalance on chromosome 11 in the stroma and tumor grade (P = .0013), on chromosomes 1, 2, 5, 18, 20, and 22 in the stroma and regional lymph node metastasis (P = .0002-.0016), and on chromosome 14 in the epithelium and progesterone-receptor expression status (P = .002). Specific markers contributing to the loss of heterozygosity/allelic imbalance on chromosome 11 in the stroma associated with tumor grade were D11S1999 (P = .00055) and D11S1986 (P = .042). The loss of heterozygosity/allelic imbalance at various markers in the stroma was significantly associated with regional lymph node metastasis: ATA42G12 (chromosome 1, P = .00095), D5S1457 (P = .00095), D5S1501 (P = .0011), D5S816 (P = .0008), D18S858 (P = .0026), D20S103 (P = .0027), D20S851 (P = .0045), D22S683 (P = .00033), and D22S1045 (P = .0013). There were more correlations between clinicopathological features and the loss of heterozygosity/allelic imbalance in the stroma than in the epithelium, suggesting that stromal genomic alterations may help account for clinical diversity. Future research is necessary to validate these results and investigate their significance for prognosis and outcome.

Prognostic Significance of Basal-Like Phenotype and Fascin Expression in Node-Negative Invasive Breast Carcinomas

Basal-like phenotype tumors are frequently found among BRCA1 germ-line mutated breast carcinomas. They are biologically aggressive and have a tendency towards visceral metastasis when untreated. Nevertheless, it has been suggested that they respond to chemotherapy better than other types of tumors. Fascin expression has been associated with lung metastasis in breast cancer. The aim of this study was to determine whether basal-like phenotype and fascin were related in both sporadic and familial tumors and with prognosis in node-negative sporadic breast cancers. 230 nonfamilial and 28 hereditary node-negative invasive breast carcinomas were immunohistochemically analyzed using tissue microarrays. Tumors that were estrogen receptor/HER2 negative and cytokeratin 5/6 and/or epidermal growth factor receptor positive were considered to have a basal-like phenotype. A basal-like phenotype was found in 11.9% of sporadic cancers. Among patients not receiving adjuvant chemotherapy, a basal-like phenotype was associated with poor prognosis (P = 0.001, log-rank test) whereas no such association was found in patients receiving it. Tumors with a basal-like phenotype showed local recurrence (17.4%) or visceral metastasis (13%) but not bone metastasis (P = 0.001). Fascin expression was observed in 25.1% of sporadic invasive breast carcinomas and was associated with the basal-like phenotype, but not with prognosis or recurrence pattern. Fascin was expressed in 83.3% and 16.7% BRCA1- and BRCA2-associated carcinomas, respectively (P = 0.048). Basal-like tumors had a tendency towards visceral metastasis and their prognosis was dependent on the use of postoperative chemotherapy. Although fascin expression was associated with the basal-like phenotype, it was not associated with their metastatic behavior. Fascin expression is frequent in BRCA1-associated tumors.

Combined Total Genome Loss of Heterozygosity Scan of Breast Cancer Stroma and Epithelium Reveals Multiplicity of Stromal Targets

Recent breast cancer studies have highlighted the importance of interactions between cancer epithelium and tumor stroma. Recently, the focus of solid tumor investigations has shifted from mutations in carcinomatous epithelium to disturbances of tissue organization in cancer. The genetic basis of this microenvironment, however, remains to be clarified. To begin to resolve this problem, a total genome loss of heterozygosity (LOH) scan was done on epithelial and stromal DNA from 134 sporadic invasive breast carcinomas. In addition to detecting more frequent LOH at three loci in stroma than in epithelium, we found strong evidence that LOH frequencies were significantly elevated in specific regions of each chromosome. We detected 57 markers, which were preferentially lost either in stroma (n = 38) or epithelium (n = 19), relative to the background LOH frequencies on their respective chromosomes. This multiplicity of stromal cell LOH, and hence loss of genetic material, provides a possible mechanism for interpatient variation in host-stromal response to invading adenocarcinoma cells. This is consistent with a model in which initial, random LOH occurs equally among epithelium and stroma, but subsequent clonal selection is driven by factors, which appear to be distinctly different between malignant epithelial and surrounding stromal cells. Genetic alterations in stroma did not mimic those in epithelium, but they could play a different and parallel role in carcinogenesis and tumor progression, probably by modifying some features specific to breast cancer.

High expression levels of p27 correlate with lymph node status in a subset of advanced invasive breast carcinomas: relation to E-cadherin alterations, proliferative activity, and ploidy of the tumors.

The cyclin-dependent kinase inhibitor p27 plays a central role in cell cycle progression and is deregulated in breast carcinomas. Although its levels are inversely associated with tumor proliferation, overexpression of p27 has been reported in a subset of rapidly proliferating breast carcinoma cell lines. p27 levels were determined by immunohistochemistry in a series of 52 sporadic invasive breast carcinomas consisting of 47 ductal, 2 lobular, and 3 mixed; most tumors were Grade 2 or 3 (46 of 52) and Tumor Node Metastasis (TNM) Stage II-IV (46 of 52). E-cadherin expression and its gene alterations at 16q22.1 were also studied, because in vitro evidence suggests a biologic association between p27 and E-cadherin-mediated growth suppression. The mean p27 labeling index (LI; percentage of p27 positive tumor cells) was 33.3% +/- 25.3% (range, 0.1-85%). High p27 levels (p27 LI, > 50%) were observed in 14 (26.9%) of 52 carcinomas and were significantly associated with metastatic disease in axillary lymph nodes (14 of 33 vs. 0 of 19; P = 0.0007 by Fisher exact test). In addition, p27 LI was higher in the group of lymph node positive vs. lymph node negative tumors (mean p27 LI, 40.9% vs. 20.1%; P = 0.008 by Mann-Whitney test). Reduced or absent E-cadherin expression was found in 27 of 45 (60%) informative cases. Allelic imbalance of the 16q22.1 locus was found in 14 (27.5%) of 51 cases by using the microsatellite markers D16S503, D16S752, and D16S512. p27 LI and E-cadherin alterations were not statistically related. In summary, high p27 levels detected in a subset of advanced breast carcinomas correlate with lymph node metastasis, suggesting that other mechanisms may bypass the cell cycle inhibitory role of p27 and provide growth advantage in these tumors.

Additional characterization of a hexanucleotide polymorphic site in the first intron of human H- ras gene : comparative study of its alterations in non-small cell lung carcinomas and sporadic invasive breast carcinomas

Intron 1 of the human H- ras gene possesses a polymorphism consisting of repetitions of the GGGCCT consensus. Three alleles have been reported at this locus. We confirmed that two, P1 and P2, display four and two repeats, respectively, with their internal sequence structure similar to that previously described. The third, P3, previously assigned as a three-unit repetition allele according to its electrophoretic mobility and with no other information regarding its internal structure, was also found. Sequence analysis of the P3 allele revealed that it consists of three perfect repeats of the GGGCCT consensus. This polymorphism is present only in human c-H- ras gene, although single hexanucleotide repeats are found scattered within intron 1 of this gene in rodents. Analysis of this locus in matched tumor/distant normal samples from: (i) 38 patients with non-small-cell lung carcinoma (NSCLC), and (ii) 35 patients with sporadic invasive breast carcinoma, revealed: (1) 6.6% and 19% loss of heterozygosity (LOH) respectively, and (2) 10.5% and 2.9% hexanucleotide instability (HI) respectively, detected by the presence of shifted in length alleles. Shifted alleles exhibited altered internal sequence structure in comparison to normal ones, suggesting complex mutational events. The same pattern of alterations was also detected in tissues adjacent to lung adenocarcinomas and dysplasias adjacent to squamous cell carcinomas (7.7% LOH, 5.9% HI), implying that abnormalities at this locus may be early events in lung carcinogenesis. The frequency of alterations (LOH vs. HI) was significantly different among NSCLC and breast cancer ( P=.005), probably due to the different tumor biology of each system. Finally, altered mRNA expression of H- ras gene was detected in all cases with HI, but this finding was also observed in samples without HI. In view of reports showing that elements in intron 1 of H- ras gene potentially influence its transcriptional regulation, from our results we cannot exclude that the hexanucleotide locus could be an element with possible involvement in expressional regulation of this gene.

Alterations of p16-pRb Pathway and Chromosome Locus 9p21–22 in Sporadic Invasive Breast Carcinomas

The p16-pRb pathway represents a vital cell-cycle checkpoint. In the present study we investigated the alterations of this G1-phase protein pathway using immunohistochemical and molecular methods in a series of 55 breast carcinomas and correlated the findings with clinicopathological features of the patients. Furthermore, we examined its relationship with the status of the chromosomal region 9p21-22 performing a deletion map analysis because there are indications that, in addition to CDKN2 and MTS2/p15(INK4B) tumor suppressor genes (TSGs), this area harbors other TSG(s). Aberrant expression (Ab) of p16 and pRb was observed in 26 (47%) and 16 (29%) of the carcinomas, respectively. A statistical trend pointing out an inverse relationship between p16 and pRb expression was found (p = 0.079). Analysis of the region that encodes for p16 by deletion mapping, a PCR-based methylation assay and PCR-SSCP, revealed that deletions and transcriptional silencing by methylation might represent the main mechanisms of CDKN2/p16(INK4A) inactivation in breast carcinomas. The results of deletion mapping also suggest that another TSG(s) may reside at the 9p21-22 area particularly at the D9S162 loci and that co-deletion of this putative gene with CDKN2/p16(INK4A) may play a role in breast carcinogenesis. In addition, microsatellite instability (MI), a marker of replication error phenotype (RER+), was observed with a frequency of 16% in the area examined and was inversely related with loss of heterozygosity (LOH). Interestingly, most cases with MI at the region encoding for p16 were aggregated in a subgroup of breast carcinomas with no other obvious genetic and/or epigenetic CDKN2/p16(INK4A) alterations. We speculate that there is an additional mechanism of CDKN2/p16(INK4A) inactivation. The relationship of p16 protein level pRb, status, the p16-pRb combined immunoprofiles, and the microsatellite alterations detected at the 9p21-22 locus with the patients' clinicopathological parameters revealed two significant correlations: one between normal pRb expression and lymph node involvement (p = 0.0263), and the other between microsatellite alterations (LOH and or MI) and tumor size (p = 9.2 x 10(-3)). In view of the heterogenous nature of breast cancer, we suggest that in a significant proportion of breast carcinomas, deregulation of the p16-pRb pathway in association with another, as-yet unidentified, TSG(s) of the 9p21-22 region may play a role in initiating or progressing the oncogenic procedure, while in other subgroups, alternative molecules may play this role.