The molecular journey from ductal carcinoma in situ to invasive breast cancer

Ductal carcinoma in situ (DCIS) accounts for approximately 20% of mammographically detected breast cancers. DCIS can recur or progress to invasive breast cancer, but the ability to predict the outcome of patients with DCIS remains limited, leading to inappropriate treatment choices. To the authors' knowledge to date, the hunt for molecular prognostic markers for DCIS has been unsuccessful. Emerging technologies, however, are shedding new light on the biologic course of DCIS. In the current study, the authors review recent findings elucidating the molecular journey from DCIS to invasive cancer and discuss how these findings will lead to more effective treatment with minimization of morbidity.     

Comparison of molecular phenotypes of ductal carcinoma in situ and invasive breast cancer

Introduction

At least four major categories of invasive breast cancer that are associated with different clinical outcomes have been identified by gene expression profiling: luminal A, luminal B, human epidermal growth factor receptor 2 (HER2) and basal-like. However, the prevalence of these phenotypes among cases of ductal carcinoma in situ (DCIS) has not been previously evaluated in detail. The purpose of this study was to compare the prevalence of these distinct molecular subtypes among cases of DCIS and invasive breast cancer.

Methods

We constructed tissue microarrays (TMAs) from breast cancers that developed in 2897 women enrolled in the Nurses' Health Study (1976 to 1996). TMA slides were immunostained for oestrogen receptor (ER), progesterone receptor (PR), HER2, cytokeratin 5/6 (CK5/6) and epidermal growth factor receptor (EGFR). Using these immunostain results, cases were grouped into molecularly defined subtypes.

Results

The prevalence of the distinct molecular phenotypes differed significantly between DCIS (n = 272) and invasive breast cancers (n = 2249). The luminal A phenotype was significantly more frequent among invasive cancers (73.4%) than among DCIS lesions (62.5%) (p = 0.0002). In contrast, luminal B and HER2 molecular phenotypes were both more frequent among DCIS (13.2% and 13.6%, respectively) as compared with invasive tumours (5.2% and 5.7%, respectively) (p < 0.0001). The basal-like phenotype was more frequent among the invasive cancers (10.9%) than DCIS (7.7%), although this difference was not statistically significant (p = 0.15). High-grade DCIS and invasive tumours were more likely to be HER2 type and basal-like than low- or intermediate-grade lesions. Among invasive tumours, basal-like and HER2 type tumours were more likely to be more than 2 cm in size, high-grade and have nodal involvement compared with luminal A tumours.

Conclusion

The major molecular phenotypes previously identified among invasive breast cancers were also identified among cases of DCIS. However, the prevalence of the luminal A, luminal B and HER2 phenotypes differed significantly between DCIS and invasive breast cancers.     

Protein kinase C alpha expression in normal breast, ductal carcinoma in situ and invasive ductal carcinoma

The purpose of this study was to determine if Protein Kinase C alpha (PKC alpha) is altered in expression or localisation in normal breast, ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC). We obtained 14 mixed cases of invasive ductal carcinoma (IDC) and DCIS, 36 pure DCIS cases and 25 cases of normal breast. The sections were stained immunohistochemically for PKC alpha expression. Staining was cytoplasmic. The results showed a progressive reduction in staining intensity from normal breast to invasive ductal carcinoma. The staining pattern was heterogeneous in the cytoplasm of DCIS and IDC, but homogeneous in the cytoplasm of normal breast ductal epithelium. Interestingly, mitotic cells and cells with aberrant nuclear morphology showed increased cytoplasmic staining in DCIS and IDC. PKC alpha activity is altered in dividing or abnormal cells, but overall expression is reduced in IDC. This raises the possibility of an alteration in the subcellular localisation of PKC alpha which may relate to changes in desmosomal adhesive state.     

Regulation of in situ to invasive breast carcinoma transition

The transition of ductal carcinoma in situ (DCIS) to invasive carcinoma is a poorly understood key event in breast tumor progression. Here, we analyzed the role of myoepithelial cells and fibroblasts in the progression of in situ carcinomas using a model of human DCIS and primary breast tumors. Progression to invasion was promoted by fibroblasts and inhibited by normal myoepithelial cells. Molecular profiles of isolated luminal epithelial and myoepithelial cells identified an intricate interaction network involving TGFbeta, Hedgehog, cell adhesion, and p63 required for myoepithelial cell differentiation, the elimination of which resulted in loss of myoepithelial cells and progression to invasion.     

Loss of heterozygosity analyses of asynchronous lesions of ductal carcinoma in situ and invasive ductal carcinoma of the human breast

BACKGROUND: Ductal carcinoma in situ (DCIS) of the breast is known to possess characteristics of the pre-invasive stage of breast cancer and is the precursor to invasive ductal carcinoma (IDC). However, the natural history of the progression from DCIS to IDC remains unknown at the molecular level. METHODS: We investigated the loss of heterozygosities (LOHs) in tumors of seven patients with a history of breast biopsy. The seven specimens were diagnosed as DCIS on histopathological re-examination. These patients were diagnosed with ipsilateral breast cancer a few years after biopsy. We used thirteen selected microsatellite markers that were mapped to and/or very close to the tumor suppressor genes or regions with frequent LOHs in breast cancer. DNA isolated from microdissected formalin-fixed, paraffin-embedded tissues was subjected to a PCR-LOH analysis for these chromosome loci, and the pattern of LOHs was compared between the two asynchronous lesions for the seven cases. RESULTS: In all patients except one, the LOHs were concordant at 91% as the informative chromosome loci in cases 1 to 6 were 56, and the concordance in LOH pattern between DCIS and IDC was detected at 50 loci. The LOHs had accumulated in accordance with the tumor progression from DCIS to IDC. The recurrent lesion occurred at or near the site of the primary biopsy and had similar or identical histopathologic features. CONCLUSIONS: These recurrences observed were probably residual disease rather than true recurrences. Our results suggest the following: (i) genetic alternations accumulate during cancer progression from DCIS to IDC, (ii) DCIS is a lesion that has a high risk of developing invasive transformation and (iii) after approximately 5 years without treatment, DCIS may develop into IDC.     

Clinicopathological significance of stromal myofibroblasts in invasive ductal carcinoma of the breast.

The purpose of this study was to investigate the distribution of CD34-positive fibroblasts and alpha-smooth muscle actin (alpha-SMA)-reactive myofibroblasts in the stroma of benign and malignant breast lesions and, secondly, to determine whether the presence of stromal myofibroblasts is associated with some of the clinicopathological characteristics of patients with invasive ductal carcinoma. The presence of stromal CD34-positive fibroblasts and myofibroblasts was investigated (as defined immunohistochemically) in 8 normal breast tissue samples, 58 invasive ductal carcinomas, 9 ductal carcinomas in situ and 16 specimens with benign lesions of the breast (fibroadenomas, ductal hyperplasias). We further studied the correlations between the presence of stromal myofibroblasts with 7 clinicopathological parameters in 58 invasive ductal carcinomas. The results indicated that the stroma of normal breast tissues contained CD34-positive fibroblasts. All benign breast lesions exhibited stromal CD34-positive fibroblasts. In contrast, the stroma of ductal carcinomas showed a complete loss of CD34-positive fibroblasts. alpha-SMA expression in stromal fibroblasts (myofibroblasts) was not detected in normal tissue samples or benign lesions except in 1 case of fibroadenoma, whereas positive myofibroblasts were found in 44.4% of ductal carcinomas in situ and 56.9% of invasive breast carcinomas. Comparison of clinicopathological parameters between invasive ductal carcinomas with and without stromal myofibroblasts revealed significant differences in lymph node metastasis, high histological grade and high microvessel density. These results suggest that CD34 loss and the presence of myofibroblasts favor the diagnosis of breast carcinoma. In invasive ductal carcinoma, the presence of stromal myofibroblasts correlated significantly with pathological parameters associated with a poor prognosis.     

Insights into the transition of ductal carcinoma in situ to invasive ductal carcinoma: morphology,molecular portraits,and the tumor microenvironment

<正>Breast cancer is posing an increasing burden and has become the cancer with the highest incidence among in women in China. The most common histological subtype of breast cancer is invasive ductal carcinoma(IDC)1,2. Ductal carcinoma in situ(DCIS) is a pre-cancerous lesion that may give rise to IDC.     

Invasive ductal carcinoma with lobular features: a comparison study to invasive ductal and invasive lobular carcinomas of the breast

Invasive ductal carcinoma with lobular features (IDC-L) is not recognized as a distinct subtype of breast cancer, and its clinicopathologic features and outcomes are unknown. In this retrospective study, we focused on characterization of clinicopathologic features and outcomes of IDC-L and compared them to invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC). 183 cases of IDC-L from 1996 to 2011 were compared with 1,499 cases of IDC and 375 cases of ILC. Available slides of IDC-L (n = 150) were reviewed to quantify the lobular component (≤20, 21–50, 51–80, >80 %), defined as small cells individually dispersed, arranged in linear cords, or in loose aggregates without the formation of tubules or cohesive nests. E-cadherin immunostain was performed to confirm ductal origin. Compared to IDC, IDC-L was more likely to have lower histologic grade (p < 0.001), be positive for estrogen receptor (96 vs. 70 %; p < 0.0001) and progesterone receptor (84 vs. 57 %; p < 0.0001), and less likely to overexpress HER-2/neu (12 vs. 23 %; p = 0.001). Despite these favorable prognostic features, IDC-L had a higher frequency of nodal metastases (51 vs. 34 %; p < 0.0001) and a worse 5-year disease-free survival than IDC (hazard ratio = 0.454; p = 0.0004). ILC and IDC-L had similar clinicopathologic features and outcomes. The proportion of the lobular component in IDC-L had no impact on the size, nodal status, stage, or outcome. Our data suggest that although IDC-L may be a variant of IDC, with >90 % of cases being E-cadherin positive, the clinical and biological characteristics are more similar to that of ILC.     

乳腺导管原位癌伴微浸润与浸润癌患者的临床特征对比分析

目的:分析乳腺导管原位癌伴微浸润（ductal carcinoma in situ with microinvasion,DCIS-MI）与乳腺浸润性导管癌（invasive ductal carcinoma,IDC）患者的临床特征、治疗方式等。方法:回顾性分析55例乳腺导管原位癌伴微浸润及508例乳腺浸润性导管癌患者的临床资料,包括两组患者的年龄、月经情况、雌激素受体（estrogen receptor,ER）、孕激素受体（progestrone receptor,PR）、人表皮生长因子受体（human epidermal growth factor,HER-2）、肿瘤细胞增殖活性标志物（Ki67）的表达情况、分子分型、治疗方式及预后。结果:DCIS-MI组和IDC组患者在年龄上的差异不具有统计学意义（P＞0.05）,DCIS-MI组在已绝经及淋巴结转移阳性比例均低于IDC组（P＜0.05）;DCIS-MI组Ki67阳性表达率显著低于IDC组（P＜0.05）,ER、PR及HER-2阳性表达率与IDC组比较差异无统计学意义（P＞0.05）。DCIS-MI组Luminal A型比例高于IDC组,而Luminal B(HER-2-)型比例低于IDC组,且差异均具有统计学意义（P＜0.05）。其余分子分型差异不具有统计学意义。DCIS-MI组患者单纯乳房切除术比例（10.9%）显著高于IDC组（0.8%）（P＜0.05）。DCIS-MI患者主要采用的手术方式为乳腺癌改良根治术和全乳切除+腋窝淋巴结清扫,其比例分别为60.0%、16.4%,与IDC组患者采用相同手术方式的比例（67.3%、19.9%）无显著差异。DCIS-MI组化疗比例、放疗比例均低于IDC组（P＜0.05）,而两组患者在内分泌治疗、靶向治疗及中药治疗方面差异不具有统计学意义（P＞0.05）。DCIS-MI组和IDC组患者的5年无病生存（disease-free survival,DFS）率分别为97.0%和81.0%,差异具有统计学意义（Log-rank,χ2=4.962,P=0.026）。结论:与IDC患者相比,DCIS-MI组患者绝经前状态比例高、淋巴结转移阳性率及Ki67阳性率更低,Luminal A型比例更高而Luminal B(HER-2-)型比例更低;DCIS-MI组患者行单纯乳房切除术比例更高,放疗及化疗比例更低,其预后更好。     

Progression from ductal carcinoma in situ to invasive breast cancer: Revisited

Ductal carcinoma in situ (DCIS) is an intraductal neoplastic proliferation of epithelial cells that is separated from the breast stroma by an intact layer of basement membrane and myoepithelial cells. DCIS is a non-obligate precursor of invasive breast cancer, and up to 40% of these lesions progress to invasive disease if untreated. Currently, it is not possible to predict accurately which DCIS would be more likely to progress to invasive breast cancer as neither the significant drivers of the invasive transition have been identified, nor has the clinical utility of tests predicting the likelihood of progression been demonstrated. Although molecular studies have shown that qualitatively, synchronous DCIS and invasive breast cancers are remarkably similar, there is burgeoning evidence to demonstrate that intra-tumor genetic heterogeneity is observed in a subset of DCIS, and that the process of progression to invasive disease may constitute an ‘evolutionary bottleneck’, resulting in the selection of subsets of tumor cells with specific genetic and/or epigenetic aberrations. Here we review the clinical challenge posed by DCIS, the contribution of the microenvironment and genetic aberrations to the progression from in situ to invasive breast cancer, the emerging evidence of the impact of intra-tumor genetic heterogeneity on this process, and strategies to combat this heterogeneity.     

Metallothionein expression in invasive and in situ breast carcinomas

BACKGROUND/METHODS: The primary aims of this study were to examine the expression of metallothionein (MT) in 123 primary invasive breast carcinomas and the in situ components of these carcinomas and to assess the association between MT expression and certain socio-demographic and clinico-pathologic characteristics. MT expression was assessed using immunohistochemical procedures and semi-quantified using an immunoreactivity score. RESULTS: Results showed that 57.7% of the invasive tumors and 43.3% of the in situ carcinomas in the study were MT-positive. Chi-squared analyses showed that MT expression was significantly higher in the tumors of women categorized as being of 'other' race and of women with tumors of high histological grade. CONCLUSIONS: The results of this study suggest that MT is a biomarker of tumor differentiation and aggressiveness and that MT expression may differ by race.     

超声及钼靶X线对乳腺导管内癌与乳腺浸润性导管癌的诊断价值

目的:探讨乳腺导管内癌（ductal caicinoma in situ,DCIS）与乳腺浸润性导管癌（invasive ductal carcinoma,IDC）的超声及钼靶X线影像特征差异。方法:回顾性分析160例患者（包括62例DCIS患者及98例IDC患者）的超声及钼靶X线资料。结果:161个乳腺病灶中,有62个DCIS病灶（DCIS组）及99个IDC病灶（IDC组）。超声对IDC组病灶的检出率明显高于DCIS组,两组间的检出率有统计学意义（P＜0.05）;两组间病灶超声表现中形状、边界、边缘特征及血流信号差异有统计学意义（P＜0.05）。钼靶X线在两组病灶检出率差异有统计学意义（P＜0.05）;两组间病灶钼靶X线表现形状及边缘特征的例数差异有统计学意义（P＜0.05）。对于DCIS组,超声及钼靶X线病灶的检出率差异有统计学意义（P＜0.05）;在病灶边缘及乳腺腺体内钙化检出率这些方面,两种方法有统计学意义（P＜0.05）。结论:乳腺钼靶X线对DCIS腺体内钙化灶诊断率较高,乳腺超声对DCIS病灶检出、病灶边缘特征显示具有诊断优势。     

Genomic differences between pure ductal carcinoma in situ and synchronous ductal carcinoma in situ with invasive breast cancer

Although ductal carcinoma in situ (DCIS) precedes invasive ductal carcinoma (IDC), the related genomic alterations remain unknown. To identify the genomic landscape of DCIS and better understand the mechanisms behind progression to IDC, we performed whole-exome sequencing and copy number profiling for six cases of pure DCIS and five pairs of synchronous DCIS and IDC. Pure DCIS harbored well-known mutations (e.g., TP53, PIK3CA and AKT1), copy number alterations (CNAs) and chromothripses, but had significantly fewer driver genes and co-occurrence of mutation/CNAs than synchronous DCIS-IDC. We found neither recurrent nor significantly mutated genes with synchronous DCIS-IDC compared to pure DCIS, indicating that there may not be a single determinant for pure DCIS progression to IDC. Of note, synchronous DCIS genomes were closer to IDC than pure DCIS. Among the clinicopathologic parameters, progesterone receptor (PR)-negative status was associated with increased mutations, CNAs, co-occurrence of mutations/CNAs and driver mutations. Our results indicate that although pure DCIS has already acquired some drivers, more changes are needed to progress to IDC. In addition, IDC-associated DCIS is more aggressive than pure DCIS at genomic level and should really be considered IDC. Finally, the data suggest that PR-negativity could be used to predict aggressive breast cancer genotypes.     

The transition from ductal carcinoma in situ to invasive breast cancer: the other side of the coin

The factors associated with the progression of ductal carcinoma in situ (DCIS) to invasive breast cancer are poorly understood. Many studies of this subject focus on the role of molecular and genetic alterations in the neoplastic epithelial cells. However, emerging evidence suggests that transition from DCIS to invasive cancer is strongly dependent upon alterations in the microenvironment. The potential roles of myoepithelial cells and of stromal-epithelial interaction are of particular interest in this regard.     

Prognostic impact of syndecan-1 expression in invasive ductal breast carcinomas

Carcinoma cells lack syndecan-1 expression when they are transiting from an epithelial to a less-differentiated mesenchymal phenotype (epithelial-mesenchymal transition, EMT). Furthermore, a shift of syndecan-1 expression from malignant epithelial cells to reactive stromal cells has also been observed during progression of many carcinomas. Finally, epithelial and/or stromal syndecan-1 expression is of prognostic value in many carcinomas. Because recent results are contradictory in breast carcinomas, we have re-evaluated the prognostic significance of syndecan-1 expression in a cohort of 80 patients with invasive ductal breast carcinomas. The tumours from 80 patients diagnosed with invasive ductal breast carcinomas were used to construct a tissue microarray, which was stained with syndecan-1 by immunohistochemistry. We correlated syndecan-1 expression with clinicopathologic parameters and relapse-free survival (RFS). Exclusive epithelial expression of syndecan-1 is observed in 61.25% of the patients, whereas exclusive stromal expression is observed in 30% of the patients. Only 8.75% of the patients had both stromal and epithelial expressions of syndecan-1. A significant correlation was found between the loss of syndecan-1 epithelial expression and the syndecan-1 stromal expression with high grade of malignancy (P=0.011). The loss of syndecan-1 epithelial expression is correlated with RFS (P=0.001). Using multivariate Cox analysis, loss of epithelial syndecan-1 expression was the only prognostic indicator (P<0.001). We concluded that the loss of syndecan-1 epithelial expression was of strong prognostic value in breast carcinomas.     

乳腺浸润性导管癌组织Ki-67表达及其分子分型的意义

目的:探讨Ki-67增殖抗原在乳腺浸润性导管癌组织中的表达及与临床病理特征、雌激素受体(ER)、孕激素受体(PR)、人表皮生长因子受体-2(C-erbB-2)和抑癌基因p53的关系.方法:采用Elivison二步法进行免疫组化染色,检测102例单侧乳腺浸润性导管癌组织中Ki-67、ER、PR、C-erbB-2和p53的表达水平,并结合患者相关临床资料进行分析.结果:Ki-67高表达(≥14％)比例占82.4％ (84/102).不同分子亚型中,luminalA型Ki-67表达率最低,三阴性(导管)最高.Ki-67表达水平与单侧浸润性导管癌患者的淋巴结转移(x2=5.007,P=0.025)、TNM分期(u=705.000,P=0.032)和组织分级(单侧Fisher:P=0.042)有明显的相关性,与患者的年龄(t=1.996,P=0.052)、肿块大小(u=859.000,P=0.502)和侵犯脉管情况(xc2=0.762,P=0.383)无明显的相关性.Ki-67表达水平与ER(r=-0.273,P=0.005)、PR(r=-0.332,P=0.001)表达程度呈负相关;与C-erbB-2(r=0.327,P=0.001)、p53(r=0.343,P=0.000)表达程度呈正相关.结论:Ki-67表达与目前乳腺癌分子分型相关,其高表达是预后不良因素.     

Nuclear grading in invasive ductal breast carcinomas

Nuclear grade (NG) was studied in cytologic material obtained from 120 fine-needle aspiration biopsies of breast lesions and compared with the NG observed in the nuclear grade of surgical biopsies of the same lesions. All lesions included were invasive breast carcinomas diagnosed cytologically and confirmed histologically. Cytologic aspirates and tissue sections were graded by cytologists and pathologists, respectively, using a multiheaded microscope. Fisher's modification of Black's NG scheme was used. An agreement was observed between the NG of cytologic material and that of surgical biopsies in 93.33% of tumors, and an interesting exercise would be to correlate the NG with other significant factors for the prognosis of breast carcinomas. The purpose of this study was to assign and correlate the NG of ductal carcinomas of the breast in fine-needle aspiration biopsies and tissue specimens from the same patients.