Protein expression and molecular analysis of c-myc gene in primary breast carcinomas using immunohistochemistry and differential polymerase chain reaction.

Overexpression of c-myc protein and amplification of c-myc were investigated by immunohistochemistry and differential polymerase chain reaction (dPCR) in 440 formalin-fixed primary breast carcinoma tissues, respectively. Overexpression of c-myc was detected in 45% (199/440) and amplification of c-myc was observed in 25% (112/440) of the primary breast carcinomas. Immunolocalization of c-myc oncoprotein was demonstrated in 35% (8/23) of the comedo subtype, 17% (3/18) of the non-comedo subtype, 37% (15/41) of the comedo DCIS and 49% (20/41) of the adjacent invasive ductal carcinomas, 21% (4/19) of the non-comedo DCIS and 37% (7/19) of the adjacent invasive lesions, 49% (133/270) of the invasive ductal carcinomas, 33% (11/33) of the invasive lobular carcinomas, 29% (6/21) of the colloid carcinomas and 47% (7/15) of the medullary carcinomas. C-myc was amplified in 13% (3/23) of the comedo DCIS, 17% (7/41) of the comedo DCIS and 24% (10/41) of the adjacent invasive ductal carcinomas, 30% (82/270) of the invasive ductal carcinomas, 21% (7/33) of the invasive lobular carcinomas, 14% (3/21) of the colloid carcinomas and 24% (4/15) of the medullary carcinomas. Amplification of c-myc was noted in 16% (3/9) of the invasive ductal carcinomas but not in the adjacent non-comedo DCIS lesions. A significant association (P<0.05) was observed between in situ components and adjacent invasive lesions for c-myc expression and amplification. Overexpression of c-myc protein was significantly correlated with poorly differentiated (P<0.05) and high proliferation index (Ki-67) (P<0.05) tumors but not with lymph node metastases (P>0.05), patient age (P>0.05) and estrogen receptor status (P>0.05). Significant relationship was also noted between amplification of c-myc and absence of estrogen receptor (P<0.05), high histological grade (P<0.05) and high proliferation index (Ki-67) (P<0.05). No relationship was seen with nodal status (P>0.05) and patient age (P>0.05). Majority of the Malaysian female patients are from younger age group (<50 years old) but overexpression and amplification of c-myc was not statistically associated with patient age (P>0.05) indicating that these alterations may be independent events of patient age. The above observations suggest that overexpression and amplification of c-myc could play an important role in tumor progression from non-invasive to invasive and, also, it may have the potential as a marker of poor prognosis of breast cancer.     

Ultrastructure of the periductal area of comedo carcinoma in situ of the breast

We have previously shown that the different biological natures of comedo ductal carcinoma in situ (DCIS) and non-comedo DCIS may, in part, be explained by the different expression patterns of tenascin, a large extracellular matrix protein, as observed by immunohistochemical studies. In the present study, we compared 8 cases of comedo DCIS with 5 cases of non-comedo DCIS by ultrastructural analysis, focusing on the myoepithelium, basal lamina, and tenascin-positive extracellular periductal stromal matrix. Our observations show that the comedo type DCIS frequently has an altered basal lamina, a looser and more disorganized collagenous matrix, and a general increase in stromal cellularity, including fibroblasts, lymphocytes, histiocytes and small blood vessels. In addition, in comedo DCIS, the lateral intercellular spaces between large myoepithelial cells that border the basal lamina are often expanded, compared to those of non-comedo DCIS. These results identify structural characteristics of comedo DCIS that may play a role in its greater preinvasive potential. They may also provide a structural basis for the different strategies that are needed for for clinical management of comedo DCIS, compared to non-comedo DCIS.     

Tenascin patterns of expression in duct carcinoma in situ of the breast

Immunohistochemical methods were used to study tenascin (TN) expression in duct carcinoma in situ (DCIS) of the breast of different histologic types. We evaluated 82 lumpectomy specimens of DCIS. There were 5 cases of comedo type, 19 cases of noncomedo type, and 58 cases of mixed comedo and noncomedo type. In 44 cases, the intraductal carcinomas were associated with infiltrating (invasive) duct carcinoma. TN expression was studied by immunohistochemical methods using monoclonal mouse anti-human tenascin (DAKO-TN2M636; 1:50 dilution). Positivity was recorded on a scale of 0 to 2+ for presence of TN staining around tumor ducts and thickness of TN-stained fibrous bands. TN showed positive correlation between thick bands around comedo DCIS and thin bands around noncomedo DCIS. The TN score had statistically significant positive association with high nuclear grade (p 0.004), periductal inflammatory infiltrate of DCIS (p 0.0006), associated extensive central necrosis of DCIS (p 0.0005), and comedo DCIS (p 0.0004). TN expression in the stroma was positively associated with tumor size (p 0.00002), extensive central necrosis (p 0.02), comedo DCIS (p 0.0005), and associated invasive carcinoma (p 0.006). The TN score did not correlate with duct size, multicentric carcinoma, or associated microcalcification. These results demonstrate the different biological nature of DCIS comedo type and suggest its preinvasive potential.     

Microinvasive ductal carcinoma (T1mic) of the breast. The clinicopathological profile and immunohistochemical features of 28 cases

Microinvasive ductal carcinoma of the breast, namely ductal carcinoma in situ with microinvasion (T1mic) as defined by the American Joint Committee on Cancer (AJCC) Staging Manual, is a rare disease, although it is increasing because of widespread use of mammography. The aim of the present study was to describe the clinicopathological and immunohistochemical features of this entity. Twenty-eight patients who were diagnosed as T1mic from January 1997 to August 2002 were studied by using 3-5 mm-thick serial sections with hematoxylin-eosin staining. Immunohistochemical staining for the estrogen receptor (ER), progesterone receptor (PR), p53, Ki-67, and HER-2 were performed. All 28 patients were female, with a mean age of 48.8 years. Twenty-six patients (93%) revealed mammographic abnormalities on routine examination. All foci of the invasions were measured using an ocular micrometer. Invasive foci consisted of isolated cells or cell clusters, or appeared as a tongue-like projection of tumor through the basement membrane of the duct of ductal carcinoma in situ (DCIS). The mean number of invasive foci was 3, and the mean size was 0.6 mm. We found that high nuclear grade and predominant comedo subtype of DCIS components were 57.1% and 46.4%, respectively. Twenty-four cases (86%) demonstrated necrosis of DCIS components. Microinvasion was often associated with periductal stromal reaction (71.5%) and/or a lymphocytic infiltration (78.6%). All patients, excluding two, received axillary resection (the mean number of lymph nodes examined per case was 12), and none had lymph node metastasis. The positive expression of ER and PR strongly related to low grade nuclei and non-comedo subtype; however, the positive expression of HER-2 and P53 related to high grade nuclei and comedo subtype (P<0.01). Ki-67 expression was significantly higher in the high grade nuclei group than in the low grade group (P<0.01). Our study suggested that high nuclear grade and comedo DCIS were more aggressive and more common with microinvasion, and that microinvasion is more likely to be multifocal.     

Overexpression of HER-2/neu and its relationship with other prognostic factors change during the progression of in situ to invasive breast cancer.

Using permanent-section immunohistochemistry, we investigated the role of HER-2/neu in the development and progression of human breast cancer by measuring its overexpression in a series of hyperplastic (n = 30), dysplastic (n = 15), and malignant neoplastic (n = 708) lesions of ductal epithelium and by evaluating the relationships between overexpression and clinicopathologic features known to have prognostic significance in these lesions. The neoplasms included pure ductal carcinoma in situ (DCIS; n = 59) and infiltrating ductal carcinoma (IDC; n = 649). The latter were all node negative and stratified into IDC combined (n = 237) or not combined (n = 412) with a "significant amount" of DCIS (defined as DCIS greater than or equal to 10% of total tumor cellularity). Overexpression of HER-2/neu was not observed in any of the hyperplastic or dysplastic lesions. In contrast, it was present in 56% of pure DCIS and in 77% of the comedo subtype of this group. Only 15% of IDC overexpressed HER-2/neu. However, the rate of overexpression was significantly higher in the subset of IDC combined with DCIS compared with the subset of IDC not combined with DCIS (22% v 11%, respectively; P less than .0001). These results are consistent with the hypothesis that HER-2/neu plays a more important role in initiation than in progression of ductal carcinomas. They also suggest that overexpression decreases within individual tumors as they evolve from in situ to increasingly invasive lesions or, alternatively, that many invasive carcinomas arise de novo (ie, without progressing through a significant in situ stage) by mechanisms not involving HER-2/neu. In addition, overexpression of HER-2/neu was associated with several poor prognostic features (younger patient age, premenopause, negative estrogen receptor status, negative progesterone receptor status, and high nuclear grade) in the subset of IDC combined with DCIS. With one exception (negative estrogen receptor status) these associations were lost in IDC not combined with DCIS, also suggesting that the role of HER-2/neu changes during the progression of human breast cancer.     

Amplification of Her-2/neu gene in Her-2/neu-overexpressing and -nonexpressing breast carcinomas and their synchronous benign, premalignant, and metastatic lesions detected by FISH in archival material.

Amplification of Her-2/neu in breast carcinoma is associated with poor prognosis, short disease-free interval, and short survival time in both node-negative and -positive patients. Little is known about the starting point of amplification of Her-2/neu and how it progresses from benign to malignant breast lesions. We attempted to address these questions by evaluating amplification of Her-2/neu in benign, premalignant, and malignant lesions using fluorescence in situ hybridization (FISH). Twenty-six patients with Her-2/neu-overexpressing invasive ductal carcinomas (as judged by strong immunoreactivity with Her-2/neu antibody) and coexisting lesions of ductal hyperplasia (DH), atypical ductal hyperplasia (ADH), ductal carcinoma in situ (DCIS) in the vicinity of the invasive tumor (as judged by review of the hematoxylin and eosin-stained sections), as well as metastatic carcinoma in axillary lymph nodes (mets) were selected for this study. In the primary carcinomas, a close relationship was present between overexpression as detected by immunohistochemistry (IHC) and amplification as demonstrated by FISH (85% concordance). Among these patients, amplification of Her-2/neu in ADH was demonstrated in 7 of 13 cases with ADH, and in DCIS, in 21 of 22 cases with DCIS. There was no amplification in DH or normal ductal epithelium. Significantly, in all 12 patients with synchronous positive axillary lymph nodes, there was concordant amplification of Her-2/neu in the primary and metastatic carcinoma. Amplification was consistent in multifocal metastases, despite morphological heterogeneity in some patients. Amplification ratios increased from ADH to DCIS to invasive carcinoma (P <.01, ADH versus DCIS; P <.05, DCIS versus invasive cancer), but there was no difference in amplification ratios between primary cancers and synchronous axillary metastases (P >.05). We also evaluated Her-2/neu amplification in 21 patients without Her-2/neu overexpression in their primary carcinomas (as judged by absent immunoreactivity with Her-2/neu antibody). Three showed amplification in both primary and metastatic lesions, with a low amplification ratio (approximately 2). One patient had amplification in the primary tumor but not in an axillary metastasis. Two patients exhibited slight amplification in the metastatic carcinoma (ratios 1.6 and 2), but not in their primary cancers. This FISH study indicates that amplification of Her-2/neu can emerge de novo in any stage of the disease process, from ADH to metastatic lesions, but most often appears first in ADH or DCIS. The degree of Her-2/neu amplification increases with progression to invasive carcinoma, there being no further increase in synchronous metastasis. Our data suggest that amplification of Her-2/neu appears to be mainly involved in initiation of breast oncogenesis and that its role in progression of breast cancers is uncertain.     

Expression of c-erbB-2 in in situ and in adjacent invasive ductal adenocarcinomas of the female breast.

Several lines of evidence have demonstrated that expression of the c-erbB-2 gene product contributes to the malignant phenotype. We and others have determined that c-erbB-2 is substantially expressed in most ductal in situ carcinomas of the comedo type, but not in other patterns of ductal carcinoma in situ or in atypical ductal hyperplasia of the breast. In the present investigation, by immunohistochemistry we inquired whether invasive ductal adenocarcinomas retained the c-erbB-2 expression status of the in situ carcinomas from which they derived. Of twelve specimens containing both cribriform/micropapillary in situ and derivative invasive adenocarcinomas in the same section, all tumor cells were negative for c-erbB-2 expression. In thirteen in situ carcinomas of the comedo type, with identifiable invasive components, ten had definite c-erbB-2 expression, and in every case there was comparable c-erbB-2 protein staining of in situ and invasive components; in three of these ten cases the staining in the in situ component tended to be more intense. These findings imply that a significant proportion of invasive mammary adenocarcinomas expressing c-erbB-2 protein is derived from ductal in situ carcinomas of the comedo type.     

HER2 status in pure ductal carcinoma in situ and in the intraductal and invasive components of invasive ductal carcinoma determined by fluorescence in situ hybridization and immunohistochemistry

AIM: To determine the HER2 status of ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC) of the breast. The increased prevalence of HER2 amplification and overexpression in DCIS is considered to be maintained in the intraductal component of IDC; however, HER2 amplification and overexpression are detected much less in IDC. METHODS AND RESULTS: Fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) were performed to detect HER2 in 270 IDCs with an intraductal component and in 50 pure DCIS samples; IHC was also performed in 116 metastatic nodes. HER2 was found to be amplified in 77 cases (28.5%) and overexpressed in 79 (29.3%) of the 270 IDCs. HER2 amplification was similar between intraductal and invasive components of the same tumour. The concordance for HER2 status between invasive and intraductal components of individual tumours was 98.5% and 99.3% by FISH and IHC, respectively. HER2 was amplified in 25 (50%) of the 50 pure DCIS samples. HER2 overexpression in metastatic nodes resembled the HER2 status in the primary tumour for 108 (93.1%) of 116 cases (kappa =0.831). CONCLUSION: Our study indicates that the intraductal component of IDC may differ biologically when compared with pure DCIS. HER2 appears to lack a critical role in the progression from DCIS to IDC and HER2 status is maintained in metastatic lesions.     

Correlation of HER2 overexpression with gene amplification and its relation to chromosome 17 aneuploidy: a 5-year experience with invasive ductal and lobular carcinomas

The HER2 oncogene shows expression or amplification, or both, in approximately 15% to 20% of breast cancers and has been associated with poor prognosis and a response to trastuzumab therapy. HER2 gene status determines the eligibility of breast cancer patients for trastuzumab therapy and a large fraction (41-56%) of these patients respond to targeted therapy. Several studies have related the increased expression of HER2 to an increased copy number of chromosome 17, rather than amplification of the HER2 gene. We compared the results of immunohistochemistry and fluorescence in situ hybridization in both invasive ductal and invasive lobular carcinomas, to determine the frequency of chromosome 17 aneuploidy associated with discordant results. In total, 390 invasive ductal carcinomas and 180 invasive lobular carcinomas diagnosed from January 2000 to December 2005 were included in the study only if results were available for immunohistochemistry (HercepTest; DAKO, Carpinteria, California) and fluorescence in situ hybridization (PathVysion HER2 DNA Probe Kit; Abbott Laboratories, Des Plaines, Illinois). Tumors classified as invasive ductal carcinomas were graded according to the Bloom-Richardson grading system. Correlation between the results of immunohistochemistry and fluorescence in situ hybridization was performed for all categories. Among invasive ductal carcinomas, 29% (115/390) showed chromosome 17 aneuploidy, mostly associated with grade 3/HER2 2+ (45%) or grade 2/HER2 3+ (55%) that were not amplified. Also, 34% (12/35) of invasive lobular carcinomas showed chromosome 17 aneuploidy; approximately one-third of these cases were HER2 2+ (33%) and HER2 3+ (37%) that were not amplified. Discordance between the results of immunohistochemistry and fluorescence in situ hybridization in both ductal and lobular carcinomas is largely associated with chromosome 17 aneuploidy.     

Comedonecrosis is an unfavorable marker in node-negative invasive breast carcinoma

Breast carcinoma is usually accompanied by an invasive component with an intraductal component, and each component shows different morphological features. We evaluated whether the presence or absence of comedonecrosis is correlated with prognosis and biological features in node-negative invasive breast carcinoma. Ninety-four node-negative breast carcinomas with an intraductal component were classified into two types: comedo type (n = 36) showing comedonecrosis partly or extensively in the intraductal component, and non-comedo type (n = 58) showing either an absence or small foci of necrosis. The Kaplan-Meier method was used to calculate disease-free survival. Immunohistochemical examination for p53 and HER-2 was conducted on the comedo (n = 35) and non-comedo (n = 47) type tumor specimens. Disease-free survival was significantly shorter in the comedo type than in the non-comedo type (P = 0.019). The expression of p53 was observed in 16 (45.7%) of the 35 comedo type cases, but only in two (4.3%) of the 47 non-comedo type cases (P < 0.0001). HER-2 overexpression was observed in seven (20.0%) of the 35 comedo type cases, while none of the 47 non-comedo type cases overexpressed HER-2 (P < 0.0001). These results suggest that the presence of comedonecrosis may be predictive of an unfavorable prognosis with aggressive biological behavior in node-negative invasive breast carcinoma.     

Analysis of loss of heterozygosity on chromosome 11q13 in atypical ductal hyperplasia and in situ carcinoma of the breast.

Identical allelic loss in invasive and adjacent in situ ductal breast carcinoma (DCIS) on chromosome 11q13 has been previously reported, providing molecular evidence for the progression of DCIS to invasive tumor. In this study we analyzed loss of heterozygosity (LOH) on 11q13 (PYGM, INT-2) in atypical ductal hyperplasia (ADH) and various histological types of in situ carcinomas of the breast in patients without invasive cancer. Twenty-four cases of in situ carcinoma and twelve cases of ADH were studied. Tissue microdissection of normal, hyperplastic, and tumor cells from fixed, paraffin-embedded sections was performed, and DNA was extracted for polymerase chain reaction. In situ tumors included both high- and low-grade DCIS. LOH was identified in six of twenty-two (27.3%) in situ tumors and in one of eleven (9%) ADH cases. Within in situ carcinomas, LOH was identified in six of seventeen (35%) high-grade DCIS but in none of six low-grade DCIS. The present results show that LOH at 11q13 occurs in an appreciable proportion of high-grade DCIS, although the rate is substantially less than in patients with concomitant DCIS and invasive tumor. LOH was identified less frequently in low-grade in situ tumors and ADH, suggesting that a putative tumor suppressor gene(s) located on chromosome 11q13 may be involved in the transition from early preneoplastic lesions to invasive breast cancer.     

Cytologic features of ductal carcinoma in situ

Fourteen cases of both palpable and non-palpable breast lesions reported as possible ductal carcinoma in situ (DCIS) on fine-needle biopsy (FNB) over a 12-mo period were retrieved from our files and compared to the subsequent histologic diagnosis. Although a definite cytologic pattern of highly cellular smears with high grade nuclei, dissociation, and background necrosis with microcalcifications emerged for comedo DCIS, it was not possible to differentiate these on cytologic grounds from high grade infiltrating carcinoma with necrosis unless mammographic findings were taken into account. Useful criteria for non-comedo low grade DCIS were high cellularity, low grade nuclei, and architectural features of papillary and three dimensional (3D) fragments, palisade arrangements, and monolayer sheets with punched out glandular lumina. We conclude that FNB has a definite role in the diagnosis of these lesions, with the limitation that invasive malignancy can never be excluded on cytologic criteria alone and clinico-radiological correlation is paramount. Diagn Cytopathol 1996;15:367–373. © 1996 Wiley-Liss, Inc.     

The role of HER2/neu overexpression/amplification in the progression of ductal carcinoma in situ to invasive carcinoma of the breast.

HER2/neu overexpression/amplification is seen more frequently in ductal carcinoma in situ, particularly high-grade ductal carcinoma in situ (50-60%), than in invasive ductal carcinoma of the breast (25-30%). To date, however, the role of HER2/neu in the progression of in situ to invasive disease has not been clarified. Two hundred fifty-one breast tumors were retrieved from the pathology files at Mount Sinai Hospital. These included 91 cases of ductal carcinoma in situ, 136 cases of invasive ductal carcinomas with associated ductal carcinoma in situ, and 24 cases of pure invasive carcinomas. All cases were reviewed and stained with two monoclonal antibodies to HER2/neu (CB11 and TAB250). Immunohistochemical staining was recorded using a semiquantitative scoring system (1). Representative cases were also investigated using fluorescence in situ hybridization. HER2/neu protein overexpression (defined as immunohistochemical staining with score of >or=5) was seen in 34% of cases of pure ductal carcinoma in situ, 17% of invasive carcinomas with associated ductal carcinoma in situ, and 12.5% of pure invasive carcinomas (P =.01). Sixty percent of cases of high-grade ductal carcinoma in situ showed HER2/neu protein overexpression, versus 29% of high-grade invasive carcinomas with associated ductal carcinoma in situ and 22% of high-grade pure invasive ductal carcinomas (P =.02). The concordance between the immunohistochemical staining in the in situ and invasive components of individual tumors was 90%. Thirty-three cases were also evaluated by fluorescence in situ hybridization and showed concordance between the immunohistochemical results and the degree of gene amplification in 91% of cases, whereas 3 of 33 cases showed HER2/neu gene amplification (HER2/CEP17 = 2.3-3.7) by fluorescence in situ hybridization in the absence of positive immunohistochemical staining. One case showed HER2/neu gene amplification in the associated ductal carcinoma in situ (HER2/CEP17 ratio = 6.5), with no evidence of gene amplification in the invasive tumor (HER2/CEP17 ratio = 1.14). Multiple genetic events are required for the development of an invasive phenotype. The findings from this study suggest that the genetic event of HER2/neu gene amplification/protein overexpression may not play a key role in the progression of ductal carcinoma in situ to invasive carcinoma and that other molecular alterations may be more important in the initiation of invasion in ductal carcinoma of the breast.     

Ductal carcinoma in situ with basal-like phenotype: a possible precursor to invasive basal-like breast cancer.

Basal-like carcinomas have recently been identified in gene expression profiling studies as a subtype of invasive breast cancer. These lesions are estrogen receptor (ER)-negative, progesterone receptor (PR)-negative, and HER2-negative (triple negative), and typically express basal cytokeratins, epidermal growth factor receptor (EGFR), and/or c-kit. As poorly differentiated invasive ductal carcinomas, they presumably have a ductal carcinoma in situ (DCIS) precursor with similar cytologic and immunophenotypic features. However, the frequency and even the existence of a DCIS lesion with an immunophenotype analogous to that of invasive basal-like carcinomas have not been previously evaluated. We studied 66 cases of high nuclear grade DCIS using antibodies to ER, PR, HER2, three basal cytokeratins, EGFR, and c-kit to determine the frequency of the triple negative phenotype, and to determine the relationship between the triple negative phenotype and expression of basal cytokeratins and other biomarkers characteristically expressed by invasive basal-like carcinomas. Four cases (6%) exhibited the triple negative phenotype; the remaining cases showed other combinations of ER, PR, and HER2 expression (nontriple negative). Basal cytokeratins, EGFR, or both were expressed by all four triple negative lesions, but by only 21 of 51 (42%) nontriple negative cases (P = 0.04). We conclude that a small proportion of high-grade ductal carcinomas in situ exhibit an ER-negative/PR-negative/HER2-negative (triple negative) phenotype, and these lesions more commonly show expression of basal cytokeratins and/or EGFR than nontriple negative high-grade DCIS. Given that invasive breast cancers typically share immunophenotypic features with the ductal carcinoma in situ from which they arise, our findings raise the possibility that the triple-negative, basal cytokeratin and/or EGFR-positive DCIS lesions we identified represent a precursor lesion to invasive basal-like carcinomas.     

20q13.2 Amplification in intraductal hyperplasia adjacent to in situ and invasive ductal carcinoma of the breast

The 20q13 region harboring recently described putative oncogenes is frequently amplified in invasive ductal carcinoma (IDC). The aim of this study was to examine the 20q13 copy number in intraduct hyperplasia (IH), atypical duct hyperplasia (ADH), and ductal carcinoma in situ (DCIS) adjacent to IDC. In 5 patients, comparative genomic hybridization (CGH) after laser microdissection revealed 20q13 amplification in four of five cases of IH, in all of three cases of IH with atypia, all five of DCIS, and all five of IDC. Fluorescence in situ hybridization (FISH) confirmed the amplification at 20q13.2 in IH in the two specimens analyzed. The amplification rate, however, was higher in DCIS and IDC. In phenotypically normal ductal epithelium normal values were found for 20q13 copy number by FISH (n=2) and CGH (n=5). Although the number of cases presented here is small, our results suggest that mutations in the 20q13.2 region in IH may be associated with accelerated proliferation and hyperplasia of the ductal epithelium. Progression to DCIS and ICD is accompanied by a further increase in the 20q13.2 copy number. Received: 17 March 1999 / Accepted: 22 June 1999     

c-erbB-2 overexpression and histological type of in situ and invasive breast carcinoma.

AIMS: To assess c-erbB-2 immunostaining in relation to morphological type of in situ and invasive breast carcinoma. METHODS: Formalin fixed, wax embedded archival tissue was used. Invasive carcinomas comprised 50 infiltrating ductal (NOS); seven medullary, 10 tubular, 15 mucinous and 24 classic invasive lobular. In situ carcinomas comprised 48 ductal (DCIS) and 10 cases of lobular (LCIS). The antibodies used were pAB1 (polyclonal) which stains cell lines that over express the c-erbB-2 oncogene, and ICR 12 (monoclonal) which stains sections of breast carcinoma known to show c-erbB-2 amplification. RESULTS: Immunostaining consistent with c-erbB-2 overexpression was found in 10 out of 50 cases of infiltrating ductal carcinoma (NOS), one of 24 infiltrating lobular carcinomas and one of seven medullary carcinomas only. Seventy per cent of ICR 12 positive cases of infiltrating ductal carcinoma also had extratumoral DCIS. Forty six per cent of pure DCIS lesions also showed strong membrane staining for c-erbB-2 protein, confined to large cell types. CONCLUSIONS: Immunostaining for c-erb B-2 oncoprotein occurs mainly in large cell DCIS and infiltrating ductal carcinoma NOS, especially those with an extratumoral DCIS component. There is a low incidence in other types of breast cancer, including those associated with a better prognosis. Different biological mechanisms may be responsible for histologically distinct types of breast carcinoma.     

Expression of MT-1 MMP, MMP2, MMP9 and TIMP2 mRNAs in ductal carcinoma in situ and invasive ductal carcinoma of the breast

We investigated the expression of membrane type-1 (MT1)-MMP, MMP2, MMP9 and TIMP2 mRNAs and their roles in ductal carcinoma in situ (DCIS) and T1 and T2 invasive ductal carcinoma of the breast. We further compared these two types of carcinomas for differences in microvessel density, and expression of angiogenic factors and CD44std. MT1-MMP, MMP2, MMP9 and TIMP2 mRNA were expressed in both DCIS and invasive ductal carcinomas. Expression rates of MT1-MMP, MMP2, MMP9 and TIMP2 mRNAs were not statistically different between DCIS and invasive ductal carcinomas, nor did they differ statistically when grouped by tumor size, histologic grade or nuclear grade of invasive ductal carcinoma. Microvessel density and expression of VEGF and TGF-beta1 were not statistically different between DCIS and invasive ductal carcinoma. CD44std expression was significantly increased in DCIS compared to invasive ductal carcinoma (p < 0.05) and it was also significantly increased in lower clinical stage, histologic grade and nuclear grade of invasive ductal carcinoma (p < 0.05). Axillary node metastasis was significantly correlated with MT1-MMP mRNA, VEGF and TGF-beta1 expression (p < 0.05) and MT1-MMP mRNA was positively correlated with VEGF expression and TIMP2 mRNA (p < 0.05). In summary, patterns of MMP mRNA expression in DCIS and invasive ductal carcinoma suggest that the invasive potential of breast carcinoma is already achieved before morphologically overt invasive growth is observed. As MT1-MMP mRNA expression is significantly correlated with axillary nodal metastasis, it may be useful as a prognostic indicator of invasive ductal carcinoma. Considering the positive correlation of MT1-MMP mRNA and TIMP2mRNA expression, our finding supports a role for TIMP2 in tumor growth, as well as the utility of CD44std as a prognostic indicator of breast cancer.     

乳腺导管原位癌组织学分级与其他预后因素的关系

目的　探讨乳腺导管原位癌组织学分级与分型以及ｃｅｒｂＢ２ 蛋白、ｐ５３ 蛋白、ＭＩＢ１ 、雌激素受体（ＥＲ） 表达的关系,以期为临床判断潜在恶性程度及预后提供参数。方法　参照Ｖａｎ Ｎｕｙｓ 分类方法,对３２ 例乳腺导管原位癌按核的分级、有无坏死进行组织学分级,并将标本行ｃｅｒｂＢ２ 蛋白、ｐ５３ 蛋白、ＭＩＢ１、ＥＲ的枸橼酸微波ＡＢＣ免疫组化法染色。结果　Ⅰ级（分化好）１２ 例（３７．５％ ） ,Ⅱ级（中度分化）９ 例（２８．１％ ） ,Ⅲ级１１ 例（３４．４％ ）。Ⅲ级患者中,９ 例为粉刺型,１ 例为微乳头状型,１ 例为实体型,Ⅲ级的ｃｅｒｂＢ２、ｐ５３ 和ＭＩＢ１ 蛋白表达的阳性率分别高于Ⅱ级和Ⅰ级,并与Ⅰ级比较差异有显著意义（ Ｐ＜０．０５） ,ＥＲ阳性率低于Ⅱ级和Ⅰ级。结论　乳腺导管原位癌Ｖａｎ Ｎｕｙｓ 组织学分级可能是一个较好的预后指标。     

Expression of androgen receptor and two androgen-induced proteins (apolipoprotein D and pepsinogen C) in ductal carcinoma in situ of the breast

AIMS: To evaluate the expression of androgen receptors (AR) and two androgen-induced proteins [apolipoprotein D (ApoD) and pepsinogen C (PepC)] in ductal carcinoma in situ (DCIS) of the breast. METHODS AND RESULTS: AR, ApoD and PepC expression was examined in 28 cases of pure DCIS and in 31 cases of DCIS adjacent to invasive carcinoma of the breast using immunohistochemical methods and then correlated with the architectural subtype, the degree of differentiation and the ostrogen receptor (ER)/progesterone receptor (PgR)/HER-2 status. We found no significant differences between pure DCIS and DCIS adjacent to invasive breast cancer regarding the percentage of positive cases for ApoD (64.3% versus 54.8%), PepC (42.9% versus 48.4%), ER (64.3% versus 58.1%), PgR (60.7% versus 58.1%) and HER-2 (39.3% versus 67.7%). However, there was a significantly higher percentage of AR+ DCIS among those adjacent to invasive carcinomas of the breast than among pure DCIS lesions (93.5% versus 60.9%) (P = 0.009). AR expression did not correlate with architectural subtype, degree of differentiation, or ER/PgR/HER-2/ApoD/PepC status, in cases of pure DCIS, nor in DCIS adjacent to invasive carcinoma of the breast. CONCLUSIONS: AR expression may represent an independent predictive factor in DCIS of the breast.     

Genetic relation of lobular carcinoma in situ, ductal carcinoma in situ, and associated invasive carcinoma of the breast.

AIMS: The mutual relation of lobular carcinoma in situ (LCIS) and ductal carcinoma in situ (DCIS) of the breast, as accepted precursor lesions of invasive breast cancer, is controversial. Because they display genetic heterogeneity, it is not clear how genetically advanced these entities are and what causes the transition to an invasive carcinoma. METHODS: Six cases of LCIS, four of them with associated lobular invasive carcinoma, four cases of intermediately differentiated DCIS with an associated invasive lobular carcinoma, and nine cases of intermediately and poorly differentiated DCIS with associated ductal invasive carcinoma were investigated by means of comparative genomic hybridisation (CGH) after microdissection and immunohistochemical staining of E-cadherin. RESULTS: LCIS was characterised by a low average rate of copy number changes, no evidence of amplifications, and a high rate of gains and losses of chromosomal material at 1q and 16q, respectively. A high degree of genetic homology with well differentiated DCIS was obvious, as reported previously. The cases of intermediately differentiated DCIS with associated lobular invasive components and lobular differentiation revealed striking homologies, and a significant difference of E-cadherin expression. The comparison of preinvasive and invasive breast lesions, irrespective of differentiation within the same patient, revealed no specific alteration that might be associated with invasion. Genetic alterations seen in invasive carcinoma were not necessarily seen in the adjacent precursor lesions. CONCLUSIONS: These results provide strong evidence that invasive breast cancer is a disease with multiple cytogenetic subclones already present in preinvasive lesions. Moreover, specific CGH alterations associated with invasion were not observed. Furthermore, the close genetic association between well differentiated and a subgroup of intermediately differentiated DCIS and LCIS led to the hypothesis that LCIS and a subgroup of DCIS are different phenotypic forms of a common genotype.