HER2/neu amplification and comedo type breast carcinoma

A common promoter hypomethylation signature in invasive breast, liver and prostate cancer cell lines reveals novel targets involved in cancer invasiveness

Cancer invasion and metastasis is the most morbid aspect of cancer and is governed by different cellular mechanisms than those driving the deregulated growth of tumors. We addressed here the question of whether a common DNA methylation signature of invasion exists in cancer cells from different origins that differentiates invasive from non-invasive cells. We identified a common DNA methylation signature consisting of hyper- and hypomethylation and determined the overlap of differences in DNA methylation with differences in mRNA expression using expression array analyses. A pathway analysis reveals that the hypomethylation signature includes some of the major pathways that were previously implicated in cancer migration and invasion such as TGF beta and ERBB2 triggered pathways. The relevance of these hypomethylation events in human tumors was validated by identification of the signature in several publicly available databases of human tumor transcriptomes. We shortlisted novel invasion promoting candidates and tested the role of four genes in cellular invasiveness from the list C11orf68, G0S2, SHISA2 and TMEM156 in invasiveness using siRNA depletion. Importantly these genes are upregulated in human cancer specimens as determined by immunostaining of human normal and cancer breast, liver and prostate tissue arrays. Since these genes are activated in cancer they constitute a group of targets for specific pharmacological inhibitors of cancer invasiveness.

Prognostic role of hormone receptors in endometrial cancer: a systematic review and meta-analysis

Background

The aim of this study was to summarize the global predicting role of hormone receptors for survival in endometrial cancer.

Methods

Eligible studies were identified and assessed for quality through multiple search strategies. Data were collected from studies comparing overall survival (OS), cancer-specific survival (CSS), or progression-free survival (PFS) in patients with elevated levels of estrogen receptor (ER), progesterone receptor (PR), or human epidermal growth factor receptor 2 (HER2) with those in patients with lower levels. The combined hazard ratios of ER, PR, and HER2 for survival were calculated.

Results

A total of 98 studies were included for meta-analysis (44 for ER, 38 for PR, and 16 for HER2). Higher levels of either ER or PR could significantly indicate better survival. The pooled hazard ratios (HRs) of ER for OS, CSS, and PFS were 0.75 (95 % CI, 0.68–0.83), 0.45 (95 % CI, 0.33–0.62), and 0.66 (95 % CI, 0.52–0.85), respectively. The combined HRs of PR for OS, CSS, and PFS reached 0.63 (95 % CI, 0.56–0.71), 0.62 (95 % CI, 0.42–0.93), and 0.45 (95 % CI, 0.30–0.68), respectively. In contrast, elevated levels of HER2 could predict worse outcome with a HR of 1.98 (95 % CI, 1.49–2.62) for OS, and a HR of 2.26 (95 % CI, 1.57–3.25) for PFS.

Conclusions

In patients with endometrial cancer, higher level of ER and PR predicted favorable survival, and increased level of HER2 was associated with poorer survival. All of the three hormone receptors had prognostic value for survival.

HER2 mRNA status contributes to the discrepancy between gene amplification and protein overexpression in gastric cancer

BACKGROUND

Human epidermal growth factor receptor 2 (HER2) is an important proto-oncogene of prognostic use in gastric cancer (GC). Fluorescence in-situ hybridization (FISH) and immunohistochemistry (IHC) are the main clinical methods of detection of HER2, but consistency between the methods is poor and the cause of the discrepancy is unclear.

AIM

To investigate the involvement of HER2 mRNA status in the disparity between gene amplification and protein overexpression.

METHODS

We investigated HER2 gene, mRNA, and protein profiles in gastric precancer and cancer tissues by use of the molecular approaches FISH, real-time polymerase chain reaction, and IHC. The relationships between HER2 and matrix metalloproteinase 9 (MMP9) and Smad7 expression were analyzed and the involvement of HER2 in the interaction between tumor cells and lymphocytes was investigated by coculturing GC cell lines with peripheral blood mononuclear cells (PBMCs).

RESULTS

HER2 protein expression was significantly increased in cancer compared with precancer (P = 0.003), and the corresponding mRNA levels were significantly lower in precancer and cancer tissues than in normal tissues (κ = 0.290, P = 0.025). HER2 mRNA levels were significantly higher in tumor than in peritumor tissue (P = 0.028), and were positively correlated with MMP9 and Smad7 mRNA levels in tumor tissues. HER2 mRNA expression in GC cell lines was increased by coculture with PBMCs.

CONCLUSIONS

Different HER2 mRNA profiles, possibly in relation to contact between tumor cells and lymphocytes, might help to explain the discrepancy between gene amplification and protein overexpression results.

A NIK-IKKα module expands ErbB2-induced tumor-initiating cells by stimulating nuclear export of p27/Kip1

IκB kinase α (IKKα) activity is required for ErbB2-induced mammary tumorigenesis. Here, we show that IKKα and its activator, NF-κB-inducing kinase (NIK), support the expansion of tumor-initiating cells (TICs) that copurify with a CD24(med)CD49f(hi) population from premalignant ErbB2-expressing mammary glands. Upon activation, IKKα enters the nucleus, phosphorylates the cyclin-dependent kinase (CDK) inhibitor p27/Kip1, and stimulates its nuclear export or exclusion. Reduced p27 expression rescues mammary tumorigenesis in mice deficient in IKKα kinase activity and restores TIC self-renewal. IKKα is also likely to be involved in human breast cancer, where its expression shows an inverse correlation with metastasis-free survival, and its presence in the nucleus of invasive ductal carcinomas (IDCs) is associated with decreased nuclear p27 abundance.

Cisplatin and ultra-violet-C synergistically down-regulate receptor tyrosine kinases in human colorectal cancer cells

Background

Platinum-containing anti-cancer drugs such as cisplatin are widely used for patients with various types of cancers, however, resistance to cisplatin is observed in some cases. Whereas we have recently reported that high dose UV-C (200 J/m²) induces colorectal cancer cell proliferation by desensitization of EGFR, which leads oncogenic signaling in these cells, in this study we investigated the combination effect of low dose cisplatin (10 μM) and low dose UV-C (10 J/m²) on cell growth and apoptosis in several human colorectal cancer cells, SW480, DLD-1, HT29 and HCT116.

Results

The combination inhibited cell cycle and colony formation, while either cisplatin or UV-C alone had little effect. The combination also induced apoptosis in these cells. In addition, the combination caused the downregulation of EGFR and HER2. Moreover, UV-C alone caused the transient internalization of the EGFR, but with time EGFR recycled back to the cell surface, while cisplatin did not affect its localization. Surprisingly, the combination caused persistent internalization of the EGFR, which results in the lasting downregulation of the EGFR.

Conclusions

The combination of low dose cisplatin and low dose UV-C synergistically exerted anti-cancer effect by down-regulating RTK, such as EGFR and HER2. These findings may provide a novel strategy for the treatment of patients with colorectal cancer.

Early Breast Cancer Precursor Lesions: Lessons Learned from Molecular and Clinical Studies

Atypical ductal hyperplasia (ADH), flat epithelial atypia (FEA), and lobular neoplasia (LN) form a group of early precursor lesions that are part of the low-grade pathway in breast cancer development. This concept implies that the neoplastic disease process begins at a stage much earlier than in situ carcinoma. We have performed a review of the published literature for the upgrade risk to ductal carcinoma in situ or invasive carcinoma in open biopsy after a diagnosis of ADH, FEA, or LN in core needle biopsy. This has revealed the highest upgrade risk for ADH (28.2% after open biopsy), followed by LN (14.9%), and FEA (10.2%). With LN, the pleomorphic subtype is believed to confer a higher risk than classical LN. With all types of precursor lesions, careful attention must be paid to the clinicopathological correlation for the guidance of the clinical management. Follow-up biopsies are generally indicated in ADH, and if there is any radiological-pathological discrepancy, also in LN or FEA.

Expression of t-DARPP mediates trastuzumab resistance in breast cancer cells

PURPOSE

We have investigated the role of t-DARPP in trastuzumab resistance in ERBB2-amplified and overexpressed breast cancer cell lines.

EXPERIMENTAL DESIGN

We have used the HR-5 and HR-6 trastuzumab-resistant cells that were established from tumors that recurred in the presence of trastuzumab therapy following xenografts of BT-474 cells in nude mice. In addition, SKBR-3 cells, engineered for stable expression of t-DARPP, and HCC-1569 cells, which have constitutive expression of t-DARPP and are de novo resistant to trastuzumab, were used.

RESULTS

We reported > or =15-fold up-regulation of mRNA and protein levels of t-DARPP in HR-5 and HR-6 cells compared with their progenitor BT-474 trastuzumab-sensitive cells. The t-DARPP expression was not regulated by changes in its promoter DNA methylation levels. The SKBR-3 cells stably expressing t-DARPP developed resistance to trastuzumab compared with their parental cells and empty vector controls (P < 0.01). The trastuzumab-resistant cell lines showed a significant increase in pAKT (Ser(473)) and BCL2 protein levels. The small interfering RNA knockdown of t-DARPP in all trastuzumab-resistant cells led to a significant reduction in ERBB2, pAKT (Ser(473)), and BCL2 protein levels with a significant decrease in cell viability (P < or = 0.001) and an increase in cleaved caspase-3 levels, indicating the progression of these cells toward apoptosis. The t-DARPP protein was associated with both heat shock protein 90 and ERBB2 forming a potential protein complex. This association may play a role in regulating ERBB2 protein in trastuzumab-resistant cells.

CONCLUSION

We conclude that t-DARPP is a novel molecular target that can mediate the therapeutic resistance to trastuzumab in breast cancer cells.

Aspects of molecular phenotype and its correlations with breast cancer behaviour and taxonomy

The assessment of breast cancer morphology remains an important element in the evaluation of prognosis and therapeutic planning for this disease. The tumour morphology reflects the molecular profile that produced it and consequently each can be predictive of the other.

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.

Assessment of histologic features and expression of biomarkers in predicting pathologic response to anthracycline-based neoadjuvant chemotherapy in patients with breast carcinoma

BACKGROUND

There is significant variability in the response of tumors to neoadjuvant chemotherapy, and the underlying mechanism for this variability is unknown. In this study, the authors investigated the roles of tumor nuclear grade, mitotic activity, and biomarker expression profiles in predicting the pathologic response of breast tumors to preoperative chemotherapy.

METHODS

Eighty-two patients with breast carcinoma participated in two clinical trials and were treated with neoadjuvant chemotherapy, which consisted of either a conventional dose of fluorouracil, doxorubicin, and cyclophosphamide (FAC) or dose-escalated FAC. The mean age of the patients was 46 years (range, 24-69 years). Nuclear grade, mitotic activity, and biomarker profile (Her2-neu and mitosin expression patterns) in pretreatment tumors were correlated with the postchemotherapy pathologic response.

RESULTS

Twelve patients (15%) had a complete pathologic response (CPR), 23 patients (28%) had a near complete response (NCR), and 47 patients (57%) had significant residual disease present either at the primary site or in the axillary lymph nodes. The authors found that the nuclear grade and mitotic activity of pretreatment tumors were correlated significantly with CPR and NCR (P = 0.002 and P = 0.004). Mitosin also was correlated significantly with CPR and NCR (P = 0.028). A higher percentage of patients with Her2-neu-positive tumors had a CPR or an NCR (P = 0.152). CPR and NCR were not correlated significantly with disease stage (P = 0.186) or lymph node positivity (P = 0.498).

CONCLUSIONS

The current results indicate that tumor nuclear grade and tumor proliferative activity (mitotic activity and mitosin immunostaining) of pretreatment tumors in patients with breast carcinoma may serve as important indicators for the pathologic responsiveness of tumors to neoadjuvant, anthracycline-based chemotherapy.

Paget's disease of the breast

Paget's disease of the breast is a rare disorder of the nipple-areola complex that is often associated with an underlying in situ or invasive carcinoma. A change in sensation of the nipple-areola, such as itching and burning, is a common presenting symptom. Objectively, eczematoid changes of the nipple-areola complex are common. The later stages of Paget's disease of the breast are characterized by ulceration and destruction of the nipple-areola complex. Eczematoid changes of the nipple-areola complex and persisting soreness or itching, without obvious reason, is a suspicious symptom for Paget's disease of the breast and calls for thorough evaluation, including mammography. Exfoliative cytology with demonstration of Paget's cells may be useful, but a negative finding does not exclude Paget's disease of the breast. Surgical biopsy is the diagnostic standard and therefore the diagnosis should always be confirmed by open (surgical) biopsy. The histogenesis of Paget's disease of the breast continues to be debated. The epidermotropic theory holds that Paget's cells are ductal carcinoma cells that have migrated from the underlying breast parenchyma to the nipple epidermis. According to the in situ transformation theory, the Paget's cells arise as malignant cells in the nipple epidermis independent from any other pathologic process within the breast parenchyma. This theory has been proposed to explain those cases in which there is no underlying mammary carcinoma or when there is a carcinoma remote from the nipple-areola complex. Each of these theories is plausible; however, treatment approaches differ markedly depending on the theory of histogenesis. Mastectomy has been considered the standard of care in the management of patients with Paget's disease of the breast. Nowadays, however, some patients with Paget's disease of the breast are candidates for breast-conserving therapy. Patients must be selected carefully on an individual basis. Until there is a better understanding of the relationship of Paget's disease of the breast to the underlying cancer the surgeon should understand the natural history and behaviour of this lesion and be aware of both the risks of under- and over-treating patients with Paget's disease of the breast.

Ductal carcinoma in situ. Part I: Definition and diagnosis

The frequency of diagnosis of ductal carcinoma in situ (DCIS) has increased in Australia, largely because of the national screening programme. Ductal carcinoma in situ presents a dilemma because of problems with its diagnosis and variations in reporting pathological and radiological findings, making it difficult to define optimal treatment and communicate information in a way that helps the patient understand the problems and make decisions. There is considerable inter-observer variation, particularly in differentiating low-grade DCIS from ductal hyperplasia, with or without atypia, but pathologists who participate in regular pathological review sessions vary less in their opinions. Mammography remains the main investigative tool for DCIS and the American College of Radiology has recommended standardized reports. A team approach is required for the removal and diagnosis of possible DCIS. Although the team may be best co-located in the one facility, this is not practical in many community hospital settings which lack on-site radiology and pathology services. The decision about how much breast tissue to remove will need to be made for each patient and depends on the size of the microcalcification and how suspicious the mammogram is for DCIS. We recommend the use of synoptic reports for DCIS, and we document the minimum factors that should be reported by pathologists. The evaluation and management of DCIS by a multidisciplinary team will allow the patient access to information required to make often difficult treatment decisions. In this paper, we review the literature about the natural history, pathology, cytology and radiology of DCIS and document the 20 critical steps required for the diagnosis of impalpable, mammographic microcalcifications suspected to be DCIS.

Progression of canine mammary tumours as reflected by DNA ploidy in primary tumours and their metastases

Thirty dogs with metastasizing mammary tumours (carcinomas, n = 22; sarcomas, n = 8) were necropsied. Flow cytometric DNA analysis was carried out on frozen primary tumours and on selected metastases from the dogs. Ductular carcinomas (n = 13) had a varying growth pattern, in terms of histology, in both the primary tumours and metastases and between different metastases. The different types of DNA ploidy, including hypodiploidy, in the primary ductular carcinomas were also seen in the tumour metastases. Dogs with primary anaplastic carcinomas (n = 7) had multiple metastases, which were in most cases near-diploid or hyperdiploid. Two dogs had spindle-cell carcinomas, which were hypodiploid in both the primary tumour and the metastases. The DNA ploidy in the metastases was retained in 16 of the 22 dogs with primary carcinomas. Fibrosarcomas (n = 5) showed different types of DNA ploidy. In two of the three dogs with diploid or near-diploid osteosarcomas, the DNA ploidy was retained in the metastases. There was a statistically significant association between mammary tumours and metastases (P = 0.0001) in terms of both histological diagnosis and DNA ploidy. The association was retained when the carcinomas were tested separately (P = 0.0001); in the sarcomas it was retained weakly in terms of histology (P = 0.0183) but not DNA ploidy (P = 0.6659). The retention of the DNA ploidy in most carcinoma metastases indicated that selection of DNA ploidy had taken place prior to metastasis. The differences in patterns of DNA ploidy between ductular and anaplastic carcinomas may reflect different pathogenesis in these types of canine mammary tumour.

Maintenance of DNA content and erbB-2 alterations in intraductal and invasive phases of mammary cancer

Ductal carcinoma in situ (intraductal carcinoma) of the breast is a commonly recognized and curable clinical entity. Patients with intraductal carcinoma are at risk to develop invasive breast cancer presumably due to a transition from the noninvasive to the invasive phase of growth. Primary breast malignancies commonly display both in situ and invasive phases of growth in the same tumor. In the current study, DNA content and alterations in the erbB-2 (HER-2/neu) oncogene product were examined simultaneously in both growth phases of primary breast cancers by image analysis. DNA content in the intraductal and invasive components of primary breast cancers were virtually identical (r = 0.979, p < 0.001). Quantitative image analysis was used to measure erbB-2 expression and categories of expression were related to copy number of the erbB-2 gene. Expression of erbB-2 was similar in both growth phases and implies identity of the erbB-2 genotype. The identity of DNA content suggests that the noninvasive and invasive phases within a single breast cancer are highly related. It is likely that erbB-2 gene number remains the same during progression from intraductal to invasive disease.

Detection of c-erbB-2 gene amplification in nipple discharge by means of polymerase chain reaction

In a patient with non-palpable breast carcinoma, c-erbB-2 gene amplification was detected by means of polymerase chain reaction (PCR) in the small number of breast carcinoma cells present in nipple discharge. Amplification of the c-erbB-2 gene is more frequent in carcinoma in situ than in invasive types. Detection by a PCR-based method may help diagnose non-palpable breast carcinoma with nipple discharge. Since this gene amplification is related to high proliferation, it might provide useful preoperative information regarding intraductal carcinoma of comedo type and predict responses to chemotherapy.

Management of ductal carcinoma in situ

Ductal carcinoma in situ (DCIS) is an early, localized stage of breast carcinoma that has an excellent prognosis when it is properly treated. The significant increase in the frequency of diagnosis of DCIS in recent years is the result of both better recognition of DCIS among pathologists and widespread use of screening mammography. Multicentricity, bilaterality and histologic subtype are important considerations in the management of this disease. The clinical presentation of DCIS is the presence of either a palpable mass or a mammographic abnormality, most frequently in the form of an area of microcalcifications. For several decades, total mastectomy was considered the appropriate treatment for DCIS, and it should still be considered the standard to which more conservative forms of treatment must be compared. Breast conservation surgery has been used with increasing frequency in the treatment of DCIS but the adequacy of this approach remains subject to controversy. Segmental mastectomy alone may be applied with caution in carefully selected patients, while the rest of the patients undergoing breast conservation surgery should be treated with breast irradiation. Axillary node dissection is generally considered unnecessary in the treatment of DCIS. There is no role for adjuvant chemotherapy in the management of this disease. The role of tamoxifen in the treatment of DCIS is not clearly defined and it should be given only to patients enrolled in clinical trials. Ongoing research should clarify the controversies surrounding DCIS and enable us to define the optimal management for this disease.

c-erbB-2 oncoprotein is not an independent prognostic parameter in primary breast carcinoma. An immunohistochemical study

The prognostic significance of c-erbB-2 oncoprotein expression was studied using the monoclonal antibody, anti-c-erbB-2 (CB-11, BioGenex) and the avidin-biotin-complex (ABC) technique. Four hundred and ninety patients with primary breast carcinoma diagnosed at Gentofte Hospital in the period 1980-1985 were included. Information about treatment, relapse-free period and overall survival was obtained from the Danish Breast Cancer Co-operative Group (DBCG). The mean follow-up period was more than 10 years. Fifteen per cent of the tumours showed positive immunoreactivity for c-erbB-2. Oncoprotein expression was correlated with presence of lymph node metastases, type of tumour, high number of mitoses, severe nuclear pleomorphism, high histological grade (poor differentiation), and absence of steroid hormone receptors. By univariate analysis, expression of c-erbB-2 oncoprotein, was correlated with poorer overall survival and shorter disease-free period in the entire cohort and in patients with lymph metastases, but not in the group of patients without lymph node metastases. By multivariate analysis, c-erbB-2 failed to be an independent prognostic marker for either disease-free period or overall survival, whereas classical histopathological parameters such as presence of lymph node metastases, high number of mitoses, high histological grade (poor differentiation) and absence of progesterone receptors turned out to be of independent prognostic significance.

p53 mutations and c-erbB-2 amplification in intraductal and invasive breast carcinomas of high histologic grade

In order to clarify the clinical significance of mutations of the p53 gene and amplification of the c-erbB-2 gene in breast carcinoma, these gene alterations were examined in 101 invasive, seven predominantly intraductal and 10 intraductal breast carcinomas by single-strand conformation polymorphism-direct sequencing or Southern blot-hybridization analysis. p53 mutations were detected in 32 (32%) of the invasive cases and two (12%) of the 17 intraductal/predominantly intraductal cases, whereas c-erbB-2 amplification was detected in 14 (14%) of the invasive and six (35%) of the intraductal/predominantly intraductal cases. Irrespective of differences in the positions and types of the mutations, cases carrying p53 mutations were almost always Grade 3 histologically and with a low hormone-receptor value. Since p53 mutations as well as c-erbB-2 amplification were detected almost selectively in Grade 3 cases but were not associated with lymph nodal status in invasive breast cancer, these two gene alterations could be indicators of prognosis of disease independent of lymph nodal status. Even in intraductal/predominantly intraductal carcinoma, these gene alterations were almost always detected in tumors of higher histologic grade. Thus, it is suggested that these gene alterations occur in breast cancers showing a high proliferation rate irrespective of the presence of invasion, and that other molecular alterations are involved in the process of breast cancer invasion.

Activated oncogenes and putative tumor suppressor genes involved in human breast cancers

Cytogeneticists first proposed that the karyotypic abnormalities identified on chromosomes 1, 3, 6, 11, 13, 16, 17, and 18 supported a genetic basis for breast cancer. Such abnormal banding patterns, however, may represent either loss-of-function or gain-of-function molecular events. RFLP analyses have since confirmed that 20-60% of primary and spontaneous human breast tumors exhibit allelic losses on these same chromosomes, although the exact genes involved at these chromosomal sites remain largely unknown. Knowledge gained about the Rb-1 and p53 tumor suppressor genes at 13q14 and 17p13 in breast and other human tumors supports the paradigm that for any chromosomal locus, allelic loss associated with a mutation in the remaining tumor allele signifies an involved tumor suppressor gene. Given this paradigm, there are nearly a dozen putative breast tumor suppressor genes under active investigation, with most investigators now focusing on various chromosome 17 loci. Among the known proto-oncogenes found activated in breast cancer, amplification of c-erbB-2 at 17q21 is the most widely studied and clinically significant gain-of-function event uncovered to date, occurring in about 20% of all primary breast tumors. The involvement of this overexpressed membrane receptor has engendered interest in related tyrosine kinase receptors, such as EGFR, IR, and IGF-I-R, as well as their respective ligands, which may be overexpressed in a greater fraction of tumors, contributing to the autocrine and paracrine regulation of breast cancer growth and metastasis. New attention is being given to the potentially oncogenic function of structurally altered nuclear transactivating steroid hormone receptors, such as ER, whose overexpression has long been used to determine endocrine therapy and prognosis for individual breast cancer patients. While c-myc was one of the first known proto-oncogenes to be found amplified and overexpressed in human breast cancers, the actual incidence and clinical significance of its activation remain disputed and in need of further study. Lastly, we can expect greater clarification about the importance of various 11q13 genes found coamplified in nearly 20% of primary breast cancers, and pursuit into the intriguing possibility that a cyclin-encoding gene represents the overexpressed locus of real interest in this amplicon. Virtually all of these important genetic abnormalities identified thus far are associated with but not restricted to human breast cancers. The absence of identifiable molecular defects relating to the tissue specificity of this malignancy must be considered a substantial gap in our basic understanding of breast carcinogenesis.(ABSTRACT TRUNCATED AT 400 WORDS)

Synthetic phosphopeptide immunogens yield activation-specific antibodies to the c-erbB-2 receptor

We inoculated rabbits with synthetic phosphopeptides, duplicating a major autophosphorylation site of the c-erbB-2 protooncogene product. The rabbits produced antisera that, after reverse immunoaffinity purification, selectively recognize the erbB-2 protein in its enzymatically active configuration. These anti-phosphopeptide antisera identify a subset of erbB-2-positive human cell lines wherein the protein is constitutively active as a tyrosine kinase. Synthetic phosphopeptides incorporating informative protein phosphorylation sites may prove useful for generating antibodies that indicate the activation state of additional tyrosine kinases and perhaps other proteins phosphorylated on serine and threonine residues.

The type 1 (EGFR-related) family of growth factor receptors and their ligands

This review considers the biology of the type 1 growth factor receptor family which is increasingly recognised as important in the control of normal cell proliferation and in the pathogenesis of human cancer. The family currently comprises three closely related members: the epidermal growth factor (EGF) receptor, c-erbB-2 and c-erbB-3, all of which show abnormalities of expression in various human tumours. The family of factors related to EGF has also expanded recently and now includes transforming growth factor alpha, heparin-binding EGF, amphiregulin, cripto and heregulin, as well as several other potential ligands for the c-erbB2-2 receptor. The involvement of these receptors and growth factors in human cancer has implications for the design of novel forms of therapy for cancer, and we review recent advances and future avenues for investigation.

Overexpression of multiple oncogenes related to histological grade of astrocytic glioma

The expression of the c-erbB-1, c-myc, Ha/N-ras and c-fos oncogenes was investigated in 62 astrocytomas of low, intermediate and high grades by immunogold silver histochemistry. Elevated expression of c-erbB-1 was observed in 95%, 48% and 86% of low, intermediate and high grade tumours respectively, c-myc in 5%, 33% and 76% respectively, Ha/N-ras in 0, 43% and 71% respectively and c-fos in 55%, 48% and 52% respectively. Controls included normal brain and tumour sections immunoreacted with pre-immune serum or with antisera absorbed with synthetic peptides. Analysis of co-overexpression revealed that low grade tumours co-overexpressed a maximum of two of these genes, intermediate grade tumours a maximum of three of these genes, while co-overexpression of all four genes was observed in some high grade tumours. Co-overexpression of c-erbB-1 and c-fos was frequently observed in low grade astrocytomas and may be predictive of non-progression. On the other hand, there was a statistically significant increase in the number of tumours overexpressing Ha/N-ras or c-myc with increasing grade of tumour, suggesting that overexpression of these two oncogenes may be indicative of progression.

Overexpression of the c-erbB-2 oncoprotein: why does this occur more frequently in ductal carcinoma in situ than in invasive mammary carcinoma and is this of prognostic significance?

Overexpression of c-erbB-2 occurs in 60% of in situ and 25% of infiltrating ductal carcinomas. We have previously found very strong associations between immunohistochemical staining for c-erbB-2 and histological pattern and nuclear size in ductal carcinoma in situ (DCIS) and less strong correlation with proliferative activity. In a further study of infiltrating ductal carcinomas we have found that, in addition to tumours arising from c-erbB-2 positive, large celled, rapidly proliferating, comedo carcinomas and c-erbB-2 negative small celled cribriform/micropapillary carcinomas with a low proliferative rate, there is a third group of c-erbB-2 negative tumours with large nuclei and variable proliferative activity. These latter tumours are not seen in pure DCIS suggesting that they have a very transient in situ stage. Therefore, although in pure DCIS c-erbB-2 positively appears to be associated with tumours with a greater invasive potential, and c-erbB-2 negativity with tumours having a more favourable prognosis, the latter is not necessarily true in infiltrating disease.

Correlation of c-erbB-2 protein expression with histologic grade, lymph node involvement and steroid receptor status in human breast tumors

The association of c-erbB-2 gene amplification product (p185) with histologic tumor type in 100 patients with primary breast cancer was determined. In 49 patients with infiltrating ductal carcinoma p185 detection was correlated with histologic findings (tumor grade, lymphnode status, receptor status). Strong positive staining for p185 protein was found in 10 patients (20%) with infiltrating ductal breast carcinoma and correlated with complete negative estrogen/progesterone receptor status and with histologic grade G3. There was neither an association with lymphnode involvement nor was there any to negative estrogen and progesterone receptor status alone. At present, we cannot say whether or not there is a correlation between the degree of c-erbB-2 gene amplification and prognosis. Follow-up studies are necessary to determine whether c-erbB-2 gene amplification allows definition of a specific subset of women who could benefit from adjuvant therapy.

Interrelations between cellular DNA content, S-phase fraction, hormone receptor status and age in primary breast cancer. A series of 1,342 consecutively detected tumors. South-East Sweden Breast Cancer Group

Estrogen and progesterone receptors were assessed by an immuno-biochemical method and DNA content was analysed by flow cytometry in a consecutive series of 1,342 frozen breast cancer samples. Forty-six percent of the ER-positive tumors were DNA diploid compared to 23% among ER-negative cases. The proportion of ER-/PR- cases was highest among hypertetraploid tumors (45%) and lowest among DNA diploids (13%). While receptor positivity and DNA ploidy were strongly related, no differences in mean receptor levels were detected when comparing DNA diploid and aneuploid cases of receptor positive tumors. In receptor positive tumors ER content--but not PR content--increased with age. S-phase fraction (SPF) was estimated in 1,165 cases (87%) with an overall mean of 8.6%. Tumors with high S-phase levels and DNA hypodiploid tumors were significantly more often found in younger than in older patients. The frequency of DNA hypodiploidy was less than 1% among women older than 75 years, while it was 8% among those aged 40 years or younger. S-phase fraction was inversely related to ER and PR status. However, while mean SPF gradually decreased with increasing levels of PR, no significant difference in S-phase fraction was seen for ER concentrations just above the cut-off level for receptor positivity. Tumors positive for both receptors showed the same pattern of DNA ploidy as ER+/PR- tumors while differences in S-phase fraction were observed between the groups. These results support that PR status better than ER status reflects hormone dependent growth in breast cancer.

Nuclear and flow cytometric characteristics associated with overexpression of the c-erbB-2 oncoprotein in breast carcinoma

The overexpression of the c-erbB-2 oncoprotein is now thought by most authors to be associated with adverse prognosis in breast carcinoma. In this study, we investigate the relationship between overexpression of the c-erbB-2 oncoprotein and nuclear size by morphometry in a series of 150 human breast carcinomas, comprising 65 cases of ductal carcinoma in situ (DCIS) and 85 cases of invasive adenocarcinoma. The mean nuclear size for c-erbB-2 positive cases of DCIS was 54.8 micron 2 and invasive carcinoma was 52.1 micron 2 respectively, in contrast with 41.6 micron 2 and 42.5 micron 2 for c-erbB-2 negative cases of DCIS and invasive carcinoma respectively. Flow cytometric examination of DNA in a subset of 91 of these tumours showed no association between tumour cell aneuploidy and c-erbB-2 overexpression. S-phase fraction could be calculated on 20 cases of DCIS and 48 invasive carcinomas. There was a strong association between c-erbB-2 overexpression, S-phase fraction (p less than 0.001) and proliferative index (p less than 0.001) in 20 cases of DCIS. A weak association of S-phase fraction and c-erbB-2 overexpression was seen in 48 invasive carcinomas (p = 0.047). This study confirms the subjective impression that there is a relationship between large tumour cell nuclear size and an overexpression of the c-erbB-2 oncoprotein, and also shows an association with increased tumour cell proliferation.

C-erbB-2 oncogene protein in in situ and invasive lobular breast neoplasia

Lobular carcinoma in situ (LCIS) has uncertain malignant potential; biologic markers that will identify patients at risk for a poor clinical outcome have been sought actively. Amplification of the c-erbB-2 protooncogene has been correlated with poor prognosis in invasive mammary carcinoma, and immunohistochemical evaluation for expression of the oncogene protein has been correlated with gene amplification. The authors retrospectively evaluated 62 cases of lobular neoplasia for expression of the c-erbB-2 gene product on formalin-fixed, deparaffinized sections, using two monoclonal anti-erbB-2 (p185) antibodies (c-neu Ab3 and m-erb) and one polyclonal anti-erbB-2 antibody (pAb 1) by the avidin-biotin-peroxidase method. All 62 cases were negative with the pAb 1 antibody; one of 62 cases was weakly positive with the c-neu Ab3 in a membranous pattern. Expression of c-erbB-2 gene product was identified on adjacent invasive ductal carcinoma in one case and in adjacent ductal carcinoma in situ in another. None of 15 cases if infiltrating lobular carcinoma was positive with either of the two anti-c-erbB-2 antibodies. Strong positivity was found on benign epithelium in one case, demonstrating epitheliosis. In summary, evidence of expression of the c-erbB-2 gene product was found in one of 57 cases of LCIS and none of 15 cases of invasive lobular carcinoma. This suggests that, in contrast to reported data concerning intraductal and invasive ductal carcinoma, c-erbB-2 oncogene amplification and/or overexpression does not play a significant role in the progression of lobular breast neoplasia.

Paget's disease of the nipple

A total of 48 women with Paget's disease of the nipple (nipple eczema containing Paget cells but without a palpable lump) presented to one surgeon over a 13-year period. Temporary healing of the nipple eczema occurred in six patients. In all, 21 of 34 patients with in situ (DCIS) or invasive ductal carcinoma had mammographic abnormalities. Treatment was by simple mastectomy (37 cases), cone excision of the nipple-areola complex (ten cases) and tamoxifen (one case). DCIS was found in 45 operative specimens (96 per cent); eight had associated invasion. The DCIS was predominantly large cell solid/comedo in type and was multifocal in seven cases (19 per cent). At a median (range) follow-up of 56 (18-96) months, four of the ten patients treated by cone excision have developed a local recurrence, two of these patients have also developed metastases. Two of the 37 patients who underwent mastectomy developed loco-regional recurrences; both had invasive foci at their first operation and remain disease free at 8 years. We no longer feel that cone excision is appropriate treatment.

The c-erbB-2 protein in primary and metastatic breast carcinomas

Material from 41 patients with primary breast carcinoma and lymph node metastases at the time of primary surgical intervention was immunostained for c-erbB-2 protein, neuron-specific enolase (NSE), and estrogen receptors. Thirty of the primary breast carcinomas were of ductal type. Six were classified as infiltrating lobular carcinomas, 2 were apocrine, 1 was mucinous, and 1 was a tubular carcinoma. One tumor could not be classified as ductal or lobular by light microscopic examination alone. The number of lymph node metastases available varied from 1 to 14 per case (median, 3.9). Nine (22%) of the primary breast carcinomas (8 ductal and 1 apocrine) expressed c-erbB-2 protein and showed c-erbB-2 gene amplification; 12 expressed NSE immunoreactivity. None expressed both markers. Estrogen receptor immunoreactivity was present in 23 of the 41 cases, including 9 of the NSE-positive cases. C-erbB2- protein-positive metastases were present in 18 cases (44%), and in 13 cases all metastases were immunostained. In 5 cases the expression of c-erbB-2 protein varied from metastasis to metastasis. NSE immunoreactivity was expressed in 10 cases, and in 3 cases with minor NSE-positive cell populations the metastatic lesions expressed c-erbB-2 protein as well. All 9 primary breast carcinomas expressing c-erbB-2 protein had lymph node metastases with c-erbB-2-immunoreactive tumor cells. Eight of the 9 c-erbB-2 protein-negative primary tumors with metastases expressing c-erbB-2 protein showed no amplification of the c-erbB-2 gene.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term survival in breast cancer related to overexpression of the c-erbB-2 oncoprotein: an immunohistochemical study using monoclonal antibody NCL-CB11

In a previous series we have shown poor short-term (3-5 years) survival for patients with tumours overexpressing the c-erbB-2 oncoprotein. In this study we employed archival paraffin-embedded tissue from patients who underwent mastectomy 10-12 years prior to assessment (n = 187). Immunohistochemical staining was carried out by an indirect immunoperoxidase technique using the novel monoclonal antibody NCL-CB11. Tumours were scored according to intensity of membrane staining. Patient and tumour information was obtained by scrutiny of clinical records. Survival analysis was carried out for both time to relapse and time to death, using the log rank test. Patients with tumours demonstrating intense membrane staining had a poor prognosis compared with the rest, with a steeply sloped survival curve over the first 4 years; the survival difference was still evident at 12 years follow-up (P less than 0.001). The survival advantage for c-erbB-2 negative patients was maintained in lymph node negative patients (P less than 0.001). However, c-erbB-2 status did not influence survival in the node positive group, where all patients had a uniformly poor outlook. These results applied to both time to relapse and time to death. In conclusion, c-erbB-2 status, determined using NCL-CB11, is a powerful prognostic indicator, defining in particular node negative patients with a particularly poor prognosis, and for whom alternative therapeutic strategies may be appropriate.

Recurrence after lumpectomy for comedo-type intraductal carcinoma of the breast

The morphologic subgroups of intraductal carcinoma in situ (DCIS) of the breast may be biologically different. Thirty-eight patients with comedo-type DCIS treated with local resection with or without radiotherapy are presented. Thirteen of 35 patients had a family history of breast cancer, with 11 patients having an affected first-degree relative. This is significantly increased over other series of breast cancer patients. Recurrence was ipsilateral in all patients and occurred at the site of the original disease. Recurrence occurred in 4 of 30 patients treated with local resection only and 2 of 8 treated with local resection plus radiotherapy. The length of mean follow-up was 39 months. Because of the paucity of studies, these results cannot be compared with others, but there does appear to be a significant incidence of local recurrence after resection for comedo-type DCIS. Immunohistochemical and oncogene studies as they relate to comedo-type DCIS are discussed.

Growth factors and oncogenes in human solid tumors: clinical aspects

Growth factors, growth factor receptors and oncogenes have been extensively studied in human tumors for some years. The purpose of this paper is to review the clinical results obtained in human cancers and their predisposing conditions or high risk groups as well as their relation with clinical, pathological characteristics and their prognosis.

Oncogenes and tumor growth factors in breast cancer. A minireview

Five oncogenes have been implied as having a role in human breast tumorigenesis: int-2, c-erbB-2 (HER-2), c-myc, c-Ha-ras and the recessive Rb-1. As far as the function and biochemistry of these oncogenes have been studied, they act at different levels and have totally different functions in the cells. They are normally cellular genes, likely to have important functions in normal cell growth or differentiation. In the tumors their regulation or function is altered, due to a wide class of mutations. The oncogenes may cooperate to result in the malignant cell phenotype. However, different oncogenes are mutated in different tumors, so that the tumors show a variable pattern at the molecular level, underlining the individuality of these tumors already described as differences in histopathology, hormone receptor expression and clinical course. The main importance of the oncogene studies is still to reveal basic pathogenetic mechanisms. When appropriate it is important to test diagnostic or prognostic significance of the oncogene mutations.

The role of the epidermal growth factor receptor and the c-erbB-2 protein in breast cancer

Breast cancer cells are derived from epithelial cells lining the ducts of the breast. One of the fundamental characteristics that distinguish tumour cells from normal cells is that cancer cells grow in an apparently unregulated way. Understanding the mechanisms that regulate the growth and differentiation of normal breast epithelial cells and the differences between these systems in cancer cells is one of the central goals of research into the cell biology of breast cancer.