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

Multitask deep learning on mammography to predict extensive intraductal component in invasive breast cancer

OBJECTIVES

To develop a multitask deep learning (DL) algorithm to automatically classify mammography imaging findings and predict the existence of extensive intraductal component (EIC) in invasive breast cancer.

METHODS

Mammograms with invasive breast cancers from 2010 to 2019 were downloaded for two radiologists performing image segmentation and imaging findings annotation. Images were randomly split into training, validation, and test datasets. A multitask approach was performed on the EfficientNet-B0 neural network mainly to predict EIC and classify imaging findings. Three more models were trained for comparison, including a single-task model (predicting EIC), a two-task model (predicting EIC and cell receptor status), and a three-task model (combining the abovementioned tasks). Additionally, these models were trained in a subgroup of invasive ductal carcinoma. The DeLong test was used to examine the difference in model performance.

RESULTS

This study enrolled 1459 breast cancers on 3076 images. The EIC-positive rate was 29.0%. The three-task model was the best DL model with an area under the curve (AUC) of EIC prediction of 0.758 and 0.775 at the image and breast (patient) levels, respectively. Mass was the most accurately classified imaging finding (AUC = 0.915), followed by calcifications and mass with calcifications (AUC = 0.878 and 0.824, respectively). Cell receptor status prediction was less accurate (AUC = 0.625-0.653). The multitask approach improves the model training compared to the single-task model, but without significant effects.

CONCLUSIONS

A mammography-based multitask DL model can perform simultaneous imaging finding classification and EIC prediction.

CLINICAL RELEVANCE STATEMENT

The study results demonstrated the potential of deep learning to extract more information from mammography for clinical decision-making.

KEY POINTS

• Extensive intraductal component (EIC) is an independent risk factor of local tumor recurrence after breast-conserving surgery. • A mammography-based deep learning model was trained to predict extensive intraductal component close to radiologists' reading. • The developed multitask deep learning model could perform simultaneous imaging finding classification and extensive intraductal component prediction.

A review of mucinous lesions of the breast

Mucinous lesions of the breast include a variety of benign and malignant epithelial processes that display intracytoplasmic or extracellular mucin, including mucocele-like lesions, mucinous carcinoma, solid papillary carcinoma, and other rare subtypes of mucin-producing carcinoma. The finding of free-floating or stromal mucin accumulations is a diagnostic challenge of which the significance depends on the clinical, radiologic, and pathologic context. This article emphasizes the differential diagnosis between benign and malignant mucin-producing lesions, with a brief consideration of potential mimics, such as biphasic and mesenchymal lesions with associated with mucinous, myxoid, or matrix material.

Mammography, US, and MRI to Assess Outcomes of Invasive Breast Cancer with Extensive Intraductal Component: A Matched Cohort Study

Background An extensive intraductal component (EIC) in breast cancer is an independent risk factor for local recurrence after surgery, especially in young, premenopausal women. Few studies have analyzed long-term outcomes or imaging features of EIC-positive breast cancer. Purpose To assess the prognostic value of EIC on recurrence-free and overall survival in breast cancer and evaluate imaging features of EIC-positive breast cancer by using mammography, US, and MRI. Materials and Methods A retrospective study of 6816 consecutive women with surgically diagnosed invasive breast cancer between January 2007 and December 2012 was performed. After individual matching, women were allocated into either an EIC-positive or an EIC-negative group. Imaging factors associated with prognosis were investigated. The recurrence-free and overall survival rates were compared. Univariable and multivariable analyses were performed to analyze the effect of EIC. Results Among 6136 included women (mean age, 48.9 years ± 9.8), 1800 EIC-positive and 4336 EIC-negative breast cancers were identified. After matching according to EIC presence was performed, 1551 women were allocated into each group. The mean follow-up period was 79.9 months. The local-regional recurrence rate in the EIC-positive group was higher than that in the EIC-negative group (39.4% [63 of 160] vs 25.5% [37 of 145]; P = .001). However, there were no significant differences in total recurrence rate (hazard ratio [HR]: 1.2; 95% confidence interval [CI]: 0.9, 1.4; P = .21) or death (HR: 1.1; 95% CI: 0.8, 1.5; P = .45). EIC was not a significant independent factor for recurrence-free survival (HR: 1.1; 95% CI: 0.9, 1.4; P = .45) or death (HR: 1.1; 95% CI: 0.8, 1.6; P = .44) in multivariable analyses. Calcification and non-mass lesions were more commonly seen at US and MRI in the EIC-positive group than in the EIC-negative group (P < .001). Conclusion The presence of an extensive intraductal component in women with invasive breast cancer did not affect overall survival or recurrence-free survival. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Eby in this issue.

Reduced Basal Nitric Oxide Production Induces Precancerous Mammary Lesions via ERBB2 and TGFβ

One third of newly diagnosed breast cancers in the US are early-stage lesions. The etiological understanding and treatment of these lesions have become major clinical challenges. Because breast cancer risk factors are often linked to aberrant nitric oxide (NO) production, we hypothesized that abnormal NO levels might contribute to the formation of early-stage breast lesions. We recently reported that the basal level of NO in the normal breast epithelia plays crucial roles in tissue homeostasis, whereas its reduction contributes to the malignant phenotype of cancer cells. Here, we show that the basal level of NO in breast cells plummets during cancer progression due to reduction of the NO synthase cofactor, BH₄, under oxidative stress. Importantly, pharmacological deprivation of NO in prepubertal to pubertal animals stiffens the extracellular matrix and induces precancerous lesions in the mammary tissues. These lesions overexpress a fibrogenic cytokine, TGFβ, and an oncogene, ERBB2, accompanied by the occurrence of senescence and stem cell-like phenotype. Consistently, normalization of NO levels in precancerous and cancerous breast cells downmodulates TGFβ and ERBB2 and ameliorates their proliferative phenotype. This study sheds new light on the etiological basis of precancerous breast lesions and their potential prevention by manipulating the basal NO level.

An Update of Mucinous Lesions of the Breast

Mucinous lesions of the breast include a variety of benign and malignant epithelial processes that display intracytoplasmic or extracellular mucin, including mucocelelike lesions, mucinous carcinoma, solid papillary carcinoma, and other rare subtypes of mucin-producing carcinoma. The most important diagnostic challenge is the finding of free-floating or stromal mucin accumulations for which the significance depends on the clinical, radiologic, and pathologic context. This article emphasizes the differential diagnosis between mucocelelike lesions and mucinous carcinoma, with a brief consideration of potential mimics, such as biphasic and mesenchymal lesions with myxoid stroma ("stromal mucin") and foreign material.

Niche-localized tumor cells are protected from HER2-targeted therapy via upregulation of an anti-apoptotic program in vivo

Several lines of evidence suggest that components of the tumor microenvironment, specifically basement membrane and extracellular matrix proteins, influence drug sensitivities. We previously reported differential drug sensitivity of tumor cells localized adjacent to laminin-rich extracellular matrix in three-dimensional tumor spheroid cultures. To evaluate whether differential intra-tumor responses to targeted therapy occur in vivo, we examined the sensitivity of human epidermal growth factor receptor 2-positive tumors to lapatinib using a previously described ductal carcinoma in situ-like model characterized by tumor cell confinement within ductal structures surrounded by an organized basement membrane. Here we show that tumor cells localized to a ‘niche’ in the outer layer of the intraductal tumors adjacent to myoepithelial cells and basement membrane are resistant to lapatinib. We found that the pro-survival protein BCL2 is selectively induced in the niche-protected tumor cells following lapatinib treatment, and combined inhibition of HER2 and BCL-2/XL enhanced targeting of these residual tumor cells. Elimination of the niche-protected tumor cells was achieved with the HER2 antibody–drug conjugate T-DM1, which delivers a chemotherapeutic payload. Thus, these studies provide evidence that subpopulations of tumor cells within specific microenvironmental niches can adapt to inhibition of critical oncogenic pathways, and furthermore reveal effective strategies to eliminate these resistant subpopulations.

Location-specific subpopulations of breast cancer cells adapt to targeted drug treatment, but therapeutic strategies exist to attack these niche-protected cells. A team led by Joan Brugge and Jason Zoeller from Harvard Medical School, USA, implanted human HER2+ breast tumor cells into the ducts of mouse mammary glands to recapitulate the architecture of ductal carcinoma in situ, a common type of non-invasive breast cancer. They found that cancer cells located on the outer rim of the tumors were resistant to lapatinib, a drug that targets the HER2 protein. Combination treatment with lapatinib and a drug that blocks a pro-survival protein called BCL2 that was specifically enriched in the outer cells after lapatinib treatment helped kill more cells. Complete elimination of the resistant cells was achieved with an antibody-drug conjugate, T-DM1, that binds to HER2 and then releases a chemotherapeutic payload.

The Significance of c-erbB-2 Overexpression and p53 Expression in Patients With Axillary Lymph Node—Negative Breast Cancer: A Tissue Microarray Study

We conducted this study to examine whether the expression of c-erbB-2 and p53 is the prognostic indicator for patients with early-stage breast cancer in which axillary lymph node metastasis is absent. We examined 326 patients with early-stage breast cancer in which axillary lymph node metastasis is absent. Tissue microarrays were constructed. Following this, immunohistochemical staining was done for estrogen receptor (ER), progesterone receptor (PR), c-erbB2, and p53. The results were as follows: (1) expression of c-erbB-2 was correlated with other clinicopathologic factors (eg, patient's age, presence of menopause, tumor size, histologic and nuclear grade, and presence of hormone receptors such as ER and PR); and (2) expression of p53 was correlated with survival rate, patient's age, presence of menopause, and tumor size. However, these results were not statistically significant. In conclusion, our results indicate that expression of c-erbB-2 and p53 did not have any prognostic value in patients with early-stage breast cancer in which axillary lymph node metastasis is absent.

Human epidermal growth factor receptor 2 and estrogen receptor status in respect to tumor characteristics in non-metastatic breast cancer

BACKGROUND

The expressions of estrogen receptor (ER) and cell surface receptor, Tyrosine Kinase Human Epidermal Growth Factor Receptor 2 (HER 2), have emerged as the most important molecular biomarkers determining the breast cancer prognosis. In this study, interactions between ER and HER2 were assessed to determine if they modulate tumor characteristics.

MATERIALS AND METHODS

Tissue samples from 120 patients with early stage breast cancer receiving adjuvant chemotherapy were reviewed to evaluate ER and HER2 status quantified by immunohistochemistry and fluorescence in situ hybridization, and the correlation of ER and HER2 with patient characteristics and tumor pathology was studied.

RESULTS

A total of 37(30.8%) and 80(66.6%) out of 120 samples were HER2 (3+ by immunohistochemistry or positive by fluorescent in situ hybridization) and ER positive (by immunohistochemistry), respectively. ER-negative tumors were significantly more likely to be HER-2 positive than were ER-positive tumors (21.25%; odds ratio, 0.270; 95% CI, 0.119 to 0.612; P = 0.002). ER positivity was associated with <2 cm tumor size and higher histological grade (P = 0.007 and 0.019, respectively). No significant correlation was seen between the co-expression of HER2 and ER and tumor characteristics.

CONCLUSION

HER2 positive tumors were less common compared to ER positive tumors in early stage breast cancer Iranian patients. Also, higher histological grade among ER negative tumors showed higher aggressiveness of the tumor. Future studies are needed to evaluate the effect of receptor status on prognosis.

Use of monoclonal antibody-IRDye800CW bioconjugates in the resection of breast cancer

BACKGROUND

Complete surgical resection of breast cancer is a powerful determinant of patient outcome, and failure to achieve negative margins results in reoperation in between 30% and 60% of patients. We hypothesize that repurposing Food and Drug Administration-approved antibodies as tumor-targeting diagnostic molecules can function as optical contrast agents to identify the boundaries of malignant tissue intraoperatively.

MATERIALS AND METHODS

The monoclonal antibodies bevacizumab, cetuximab, panitumumab, trastuzumab, and tocilizumab were covalently linked to a near-infrared fluorescence probe (IRDye800CW) and in vitro binding assays were performed to confirm ligand-specific binding. Nude mice bearing human breast cancer flank tumors were intravenously injected with the antibody-IRDye800 bioconjugates and imaged over time. Tumor resections were performed using the SPY and Pearl Impulse systems, and the presence or absence of tumor was confirmed by conventional and fluorescence histology.

RESULTS

Tumor was distinguishable from normal tissue using both SPY and Pearl systems, with both platforms being able to detect tumor as small as 0.5 mg. Serial surgical resections demonstrated that real-time fluorescence can differentiate subclinical segments of disease. Pathologic examination of samples by conventional and optical histology using the Odyssey scanner confirmed that the bioconjugates were specific for tumor cells and allowed accurate differentiation of malignant areas from normal tissue.

CONCLUSIONS

Human breast cancer tumors can be imaged in vivo with multiple optical imaging platforms using near-infrared fluorescently labeled antibodies. These data support additional preclinical investigations for improving the surgical resection of malignancies with the goal of eventual clinical translation.

Preliminary results of centralized HER2 testing in ductal carcinoma in situ (DCIS): NSABP B-43

NSABP B-43 is the first prospective, randomized phase III multi-institution clinical trial targeting high-risk, HER2-positive DCIS. It compares whole breast irradiation alone with WBI given concurrently with trastuzumab in women with HER2-positive DCIS treated by lumpectomy. The primary aim is to determine if trastuzumab plus radiation will reduce in-breast tumor recurrence. HER2-positive DCIS was previously estimated at >50 %, occurring primarily in ER-negative, comedo-type DCIS of high nuclear grade. There has been no documented centralized multi-institutional HER2 analysis of DCIS. NSABP B-43 provides a unique opportunity to evaluate this in a large cohort of DCIS patients. Patients undergoing lumpectomy for DCIS without evidence of an invasive component are eligible. A central review of each patient's pure DCIS lesion is carried out by immunohistochemistry analysis. If the lesion is 2+, FISH analysis is performed. Patients whose tumors are HER2 3+ or FISH-positive are randomly assigned to receive two doses of trastuzumab during WBI or WBI alone. NSABP B-43 opened 11/9/08. As of 7/31/2013, 5,861 patients have had specimens received centrally, and 5,645 of those had analyzable blocks; 1,969 (34.9 %) were HER2 positive. A total of 1,428 patients have been accrued, 1,137 (79.6 %) of whom have follow-up information. The average follow-up time for the 1,137 patients is 23.3 months. No grade 4 or 5 toxicity has been observed. In NSABP B-43 the HER2-positive rate for pure DCIS among patients undergoing breast-preserving surgery is 34.9 %, lower than the previously reported rate. No trastuzumab-related safety signals have been observed. Interest in this trial has been robust.

Molecular mapping the presence of druggable targets in preinvasive and precursor breast lesions: a comprehensive review of biomarkers related to therapeutic interventions

The analysis of clinical breast samples using biomarkers is integral to current breast cancer management. Currently, a limited number of targeted therapies are standard of care in breast cancer treatment. However, these targeted therapies are only suitable for a subset of patients and resistance may occur. Strategies to prevent the occurrence of invasive lesions are required to reduce the morbidity and mortality associated with the development of cancer. In theory, application of targeted therapies to pre-invasive lesions will prevent their progression to invasive lesions with full malignant potential. The diagnostic challenge for pathologists is to make interpretative decisions on early detected pre-invasive lesions. Overall, only a small proportion of these pre-invasive lesions will progress to invasive carcinoma and morphological assessment is an imprecise and subjective means to differentiate histologically identical lesions with varying malignant potential. Therefore differential biomarker analysis in pre-invasive lesions may prevent overtreatment with surgery and provide a predictive indicator of response to therapy. There follows a review of established and emerging potential druggable targets in pre-invasive lesions and correlation with lesion morphology.

Protein biomarkers for the early detection of breast cancer

Advances in breast cancer control will be greatly aided by early detection so as to diagnose and treat breast cancer in its preinvasive state prior to metastasis. For breast cancer, the second leading cause of cancer-related death among women in the United States, early detection does allow for increased treatment options, including surgical resection, with a corresponding better patient response. Unfortunately, however, many patients' tumors are diagnosed following metastasis, thus making it more difficult to successfully treat the malignancy. There are, at present, no existing validated plasma/serum biomarkers for breast cancer. Only a few biomarkers (such as HER-2/neu, estrogen receptor, and progesterone receptor) have utility for diagnosis and prognosis. Thus, there is a great need for new biomarkers for breast cancer. This paper will focus on the identification of new serum protein biomarkers with utility for the early detection of breast cancer.

Gene amplification in ductal carcinoma in situ of the breast

Multiple different biologically and clinically relevant genes are often amplified in invasive breast cancer, including HER2, ESR1, CCND1, and MYC. So far, little is known about their role in tumor progression. To investigate their significance for tumor invasion, we compared pure ductal carcinoma in situ (DCIS) and DCIS associated with invasive cancer with regard to the amplification of these genes. Fluorescence in situ hybridization (FISH) was performed on a tissue microarray containing samples from 130 pure DCIS and 159 DCIS associated with invasive breast cancer. Of the latter patients, we analyzed the intraductal and invasive components separately. In addition, lymph node metastases of 23 patients with invasive carcinoma were included. Amplification rates of pure DCIS and DCIS associated with invasive cancer did not differ significantly (pure DCIS vs. DCIS associated with invasive cancer: HER2 22.7 vs. 24.2%, ESR1 19.0 vs. 24.1%, CCND1 10.0 vs. 14.8%, MYC 11.8 vs. 6.5%; P > 0.05). Furthermore, we observed a high concordance of the amplification status for all genes if in situ and invasive carcinoma of individual patients were compared. This applied also to the corresponding lymph node metastases. Our results indicate no significant differences between the gene amplification status of DCIS and invasive breast cancer concerning HER2, ESR1, CCND1, and MYC. Therefore, our data suggest an early role of all analyzed gene amplifications in breast cancer development but not in the initiation of invasive tumor growth.

Comparative evaluation of the erbB2 and hormone receptor status of neighboring invasive and in situ components of ductal carcinomas of the breast

Background

It remains unknown whether erbB2 expression and hormone receptor status predict the invasive potential of ductal carcinoma in situ (DCIS) of the breast.

Objectives

To examine erbB2 and estrogen/progesterone receptor (ER/PR) status in the precise areas where DCIS turns into invasive ductal carcinoma (IDC).

Subjects and methods

Eighty-seven cases of breast malignancies harboring contiguous regions of DCIS and IDC were selected. Separate histological samples from the DCIS and the neighboring IDC were obtained using tissue microarrays. The erbB2 and ER/PR statuses were assessed using immunohistochemistry (erbB2 and ER/PR) and fluorescence in situ hybridization (FISH – only erbB2).

Results

The expression of erbB2 did not differ in the DCIS and IDC components of the breast tumors (p=0.35). There was good agreement in sample-by-sample comparisons of erbB2 (intraclass correlation coefficient [ICC]=0.78), PR (ICC=0.61) and ER (ICC=0.70) expression in the DCIS and IDC components.

Conclusion

Our findings suggest that the expressions of erbB2 and ER/PR do not differ in the contiguous regions from DCIS to IDC.

Lobular Carcinoma in Situ, Classical Type and Unusual Variants

The morphologic spectrum of lobular carcinoma in situ (LCIS) includes the classical type and unusual variants recently described. In this article we review the morphology of LCIS and highlight ways to distinguish it from its morphologic mimickers.

The role of HER2 in early breast cancer metastasis and the origins of resistance to HER2-targeted therapies

The HER2 gene encodes the receptor tyrosine kinase HER2 and is often over-expressed or amplified in breast cancer. Up-regulation of HER2 contributes to tumor progression. Many aspects of tumor growth are favorably affected through activation of HER2 signaling. Indeed, HER2 plays a role in increasing proliferation and survival of the primary tumor and distant lesions which upon completion of full transformation cause metastases. P185(HER2/neu) receptors and signaling from them and associated molecules increase motility of both intravasating and extravasating cells, decrease apoptosis, enhance signaling interactions with the microenvironment, regulate adhesion, as well as a multitude of other functions. Recent experimental and clinical evidence supports the view that the spread of incompletely transformed cells occurs at a very early stage in tumor progression. This review concerns the identification and characterization of HER2, the evolution of the metastasis model, and the more recent cancer stem cell model. In particular, we review the evidence for an emerging mechanism of HER2(+) breast cancer progression, whereby the untransformed HER2-expressing cell shows characteristics of stem/progenitor cell, metastasizes, and then completes its final transformation at the secondary site.

In situ and invasive lobular neoplasia of the breast

Lobular neoplasia of the breast represents a group of related malignancies with clinical implications ranging from risk lesions [atypical lobular hyperplasia and lobular carcinoma in situ (LCIS)] through to aggressive invasive lesions, notably invasive pleomorphic lobular carcinoma. The diversity in lobular carcinoma is evident at the morphological level, at the molecular marker level and in cytogenetic profiles. Research in these areas is already changing the face of the disease group, for example suggesting that some lobular and ductal carcinomas are closely related and even that one of the lobular group, the tubulo-lobular carcinomas, should, in fact, be regarded as a ductal cancer. More research is required to understand the long-term pathogenic implications of a diagnosis of in situ lobular neoplasia, particularly pleomorphic LCIS, and to understand the genetics behind the well-recognized high risk of bilateral disease. For invasive carcinoma, molecular studies will allow refinement of therapy and the possibility of novel targeted therapies, for example directed against fibroblast growth factor receptor 1.

Human epidermal growth factor receptor 2 status correlates with lymph node involvement in patients with estrogen receptor (ER) negative, but with grade in those with ER-positive early-stage breast cancer suitable for cytotoxic chemotherapy

PURPOSE

Human epidermal growth factor receptor 2 (HER-2) expression is associated with increased risk of high-grade disease, nodal metastasis, and absence of estrogen receptors (ERs) in early breast cancer. We tested interactions between ER and HER-2 to determine if they may modulate breast cancer nodal metastasis and proliferation.

PATIENTS AND METHODS

Tumors from the Cancer Research UK Taxotere as Adjuvant Chemotherapy phase III trial were tested for HER-2 using current diagnostic procedures. ER status, progesterone status, clinicopathologic characteristics, and patient age were included in a logistic regression analysis to identify associations with HER-2 status (positive v negative).

RESULTS

A total of 841 (23.6%) of 3,565 samples were HER-2 positive (3+ by immunohistochemistry or positive by fluorescent in situ hybridization). ER-negative tumors were more likely to be HER-2 positive than were ER-positive tumors (odds ratio [OR] = 1.87, ER negative v ER positive; P < .001). For ER-positive tumors, risk of HER-2 positivity increased by grade (OR = 7.6, grade 3 v grade 1; P < .001) but not nodal status (OR = 1.3, four or more positive nodes v node negative; P = .08). Conversely, ER negative node-positive tumors were markedly more frequently HER-2 positive than node-negative cases (OR = 3.05, four or more positive nodes v node negative; P < .001) but independent of grade (OR = 0.82, grade 3 v grade 1; P = .76).

CONCLUSION

In early breast cancer patients selected for cytotoxic chemotherapy, we identified significant interactions between HER-2 and ER expression that correlate with tumor pathology. In ER-positive breast cancers, HER-2 expression correlates with grade, not nodal metastasis. In ER-negative breast cancers, HER-2 expression correlates with increased nodal positivity, not grade. ER and HER-2 expression may modify tumor pathology via ER/HER-2-mediated cross talk.

Molecular and Morphologic Distinctions between Infiltrating Ductal and Lobular Carcinoma of the Breast

Histopathologic distinction between ductal and lobular carcinomas of the breast has been made since 1941. Together, these two subtypes account for >95% of all mammary carcinomas. With the recent advances in molecular techniques, our understanding of the biology behind these carcinomas has greatly expanded. The genomic aberrations in mammary carcinoma are highly complex and appear to be more associated with tumor grade rather than any histopathologic subtype. Protein and RNA expression profiling reveals a classification of mammary carcinoma that has some overlap with traditional histopathology and can at least partially explain clinical behavior. The goal of this review is to present what is currently known about the molecular profiles of infiltrating ductal and lobular carcinoma and how they relate to conventional histopathology and biologic behavior.

The t10,c12 isomer of conjugated linoleic acid stimulates mammary tumorigenesis in transgenic mice over-expressing erbB2 in the mammary epithelium

Conjugated linoleic acid (CLA), a family of isomers of octadecadienoic acid, inhibits rat mammary carcinogenesis, angiogenesis, and lung metastasis from a transplantable mammary tumor. c9,t11-CLA, the predominant isomer in dairy products, and t10,c12-CLA, a component of CLA supplements, are equally effective. The objective of the current studies was to test the efficacy of these two CLA isomers in a clinically relevant breast cancer model. Transgenic mice over-expressing erbB2 in the mammary epithelium were fed control or 0.5% CLA-supplemented diets continuously from weaning. Unexpectedly, t10,c12-CLA stimulated lobular hyperplasia of the mammary epithelium and accelerated mammary tumor development, decreasing median tumor latency to 168 days of age compared with 256 and 270 days in the c9,t11-CLA and control groups, respectively. Metastasis was also increased by t10,c12-CLA, with percentage of tumor-bearing mice with lung metastasis 73, 14 and 31% in the t10,c12-CLA, c9,t11-CLA and control groups, respectively. A second study, in which CLA administration was initiated after puberty, confirmed the stimulatory effect of t10,c12-CLA on mammary tumor development and metastasis. Additionally, t10,c12-CLA, but not c9,t11-CLA, increased the size of the liver, heart, spleen and mammary lymph node. The effects of t10,c12-CLA were not specific to erbB2 transgenic mice, as t10,c12-CLA supplementation increased proliferation in the mammary epithelium of both wild-type FVB and FVB/erbB2 mice. Moreover, the number of terminal end buds, the mammary epithelial structures most sensitive to a carcinogenic insult, was increased 30-fold in FVB wild-type mice fed t10,c12-CLA. These data suggest that it would be prudent to avoid CLA supplements containing the t10,c12-CLA isomer. However, even though c9,t11-CLA was not efficacious in the erbB2 model, its ability to inhibit mammary tumor development in rat models suggests that it may have activity for prevention of some types of breast cancer.

Detection of HER-2/neu gene amplification in breast carcinomas using quantitative real-time PCR - a comparison with immunohistochemical and FISH results

The aim of our study was to evaluate the value of quantitative real-time-PCR (qPCR) in the determination of HER-2/neu amplification status of human breast carcinomas by comparing qPCR, FISH and immunohistochemistry results from the same samples. A total of 210 breast carcinomas were examined. Ready-to-use CB11 antibody was applied to detect HER-2/neu oncoprotein expression. In 76 out of 210 cases FISH was performed, and 162 cases were investigated with qPCR. Seventy-five tumors were 2+ or 3+ positive with immunohistochemistry, while 135 samples were either completely negative or 1+. In 45 cases results from all three methods were available. Out of these, in twenty negative and sixteen positive cases both FISH and qPCR led to similar results. The mean qPCR amplification ratio in the concordant positive cases was 5.424 while in the qPCR+/FISH- group the mean ratio was 2.765. Out of 121 samples with scores of 0 or 1+ immunohistochemical result, analyzed also with qPCR, 26 showed HER-2/neu gene amplification. In these cases the mean amplification ratio was 2.53. Comparison of FISH and qPCR together with immunohistochemistry shows that qPCR is more sensitive to detect HER-2/neu gene amplification in tumors scored as 2+ with immunohistochemistry, but the diagnostic cut-off ratio should be defined above 2.7 to avoid high number of false positive cases. Amongst the immunohistochemistry score 2+ cases, 10 of 18 showed gene amplification by qPCR while 10 of 26 by FISH. In conclusion, a well calibrated HER-2/neu qPCR assay may serve as useful alternative to FISH in breast cancer patients.

The management of lobular carcinoma in situ (LCIS). Is LCIS the same as ductal carcinoma in situ (DCIS)?

Lobular carcinoma in situ was first described over 60 years ago. Despite the long history, it continues to pose significant difficulties in screening, diagnosis, management and treatment. This is partly due its multi-focal and bilateral presentation, an incomplete understanding of its biology and natural history and perpetuation of misconceptions gathered over the last decades. In this review, the working group on behalf of EUSOMA has attempted to summarise the current thinking and management of this interesting lesion.

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.

HER-2 overexpression differentially alters transforming growth factor-beta responses in luminal versus mesenchymal human breast cancer cells

Introduction

Amplification of the HER-2 receptor tyrosine kinase has been implicated in the pathogenesis and aggressive behavior of approximately 25% of invasive human breast cancers. Clinical and experimental evidence suggest that aberrant HER-2 signaling contributes to tumor initiation and disease progression. Transforming growth factor beta (TGF-β) is the dominant factor opposing growth stimulatory factors and early oncogene activation in many tissues, including the mammary gland. Thus, to better understand the mechanisms by which HER-2 overexpression promotes the early stages of breast cancer, we directly assayed the cellular and molecular effects of TGF-β1 on breast cancer cells in the presence or absence of overexpressed HER-2.

Methods

Cell proliferation assays were used to determine the effect of TGF-β on the growth of breast cancer cells with normal or high level expression of HER-2. Affymetrix microarrays combined with Northern and western blot analysis were used to monitor the transcriptional responses to exogenous TGF-β1 in luminal and mesenchymal-like breast cancer cells. The activity of the core TGF-β signaling pathway was assessed using TGF-β1 binding assays, phospho-specific Smad antibodies, immunofluorescent staining of Smad and Smad DNA binding assays.

Results

We demonstrate that cells engineered to over-express HER-2 are resistant to the anti-proliferative effect of TGF-β1. HER-2 overexpression profoundly diminishes the transcriptional responses induced by TGF-β in the luminal MCF-7 breast cancer cell line and prevents target gene induction by a novel mechanism that does not involve the abrogation of Smad nuclear accumulation, DNA binding or changes in c-myc repression. Conversely, HER-2 overexpression in the context of the mesenchymal MDA-MB-231 breast cell line potentiated the TGF-β induced pro-invasive and pro-metastatic gene signature.

Conclusion

HER-2 overexpression promotes the growth and malignancy of mammary epithelial cells, in part, by conferring resistance to the growth inhibitory effects of TGF-β. In contrast, HER-2 and TGF-β signaling pathways can cooperate to promote especially aggressive disease behavior in the context of a highly invasive breast tumor model.

Clinical significance of K-ras and c-erbB-2 mutations in pancreatic adenocarcinoma and chronic pancreatitis

BACKGROUND

The differentiation of chronic pancreatitis (CP) from pancreatic adenocarcinoma (PA) remains the great challenge for clinicians. The purpose of this study was to compare the prevalence of K-ras and c-erbB-2 mutations in PA and CP in order to evaluate their usefulness in differential diagnosis of those diseases.

METHODS

The study included 49 patients who underwent Whipple resection or distal pancreatectomy for pancreatic adenocarcinoma (26 subjects) or chronic pancreatitis (23 subjects). DNA from pancreatic tissue was analyzed for K-ras codon 12 and c-erbB-2 mutations with PCR amplifications.

RESULTS

The K-ras gene mutation has been shown in 20 (76.9%) PA cases and in 8 (34.8%) CP cases (p<0.01). Prevalence of c-erbB-2 amplification in patients with PA was 17 (65.3%), which was not different from CP, 16 (56.5%) (p=0.58). There was a significant correlation between K-ras mutation and lymph node metastases (p=0.025) as well as between K-ras mutation and G3 tumor differentiation (p=0.037). Overall median survival in patients with PA was 9.5 mo. There was no relationship between presence of K-ras (p=0.58) or c-erbB-2 (p=0.17) mutation and survival time in PA patients.

CONCLUSION

Those results may indicate that both K-ras and c-erbB-2 play a role in pancreatic carcinogenesis, however only K-ras may provide an additional tool in differential diagnosis of CP and PC.

Clinical significance of K-ras and c-erbB-2 mutations in pancreatic adenocarcinoma and chronic pancreatitis

BACKGROUND

The differentiation of chronic pancreatitis (CP) from pancreatic adenocarcinoma (PA) remains the great challenge for clinicians. The purpose of this study was to compare the prevalence of K-ras and c-erbB-2 mutations in PA and CP in order to evaluate their usefulness in differential diagnosis of those diseases.

METHODS

The study included 49 patients who underwent Whipple resection or distal pancreatectomy for pancreatic adenocarcinoma (26 subjects) or chronic pancreatitis (23 subjects). DNA from pancreatic tissue was analyzed for K-ras codon 12 and c-erbB-2 mutations with PCR amplifications.

RESULTS

The K-ras gene mutation has been shown in 20 (76.9%) PA cases and in 8 (34.8%) CP cases (p<0.01). Prevalence of c-erbB-2 amplification in patients with PA was 17 (65.3%), which was not different from CP, 16 (56.5%) (p=0.58). There was a significant correlation between K-ras mutation and lymph node metastases (p=0.025) as well as between K-ras mutation and G3 tumor differentiation (p=0.037). Overall median survival in patients with PA was 9.5 mo. There was no relationship between presence of K-ras (p=0.58) or c-erbB-2 (p=0.17) mutation and survival time in PA patients.

CONCLUSION

Those results may indicate that both K-ras and c-erbB-2 play a role in pancreatic carcinogenesis, however only K-ras may provide an additional tool in differential diagnosis of CP and PC.

Biomarker profile and genetic abnormalities in lobular carcinoma in situ

The predisposition of patients with lobular carcinoma in situ (LCIS) to develop invasive breast cancer (IBC) is well known. However, relatively little is known about the biologic characteristics, which may be involved in the development and progression of LCIS. This study evaluated 59 cases of LCIS (29 pure, 30 with synchronous IBC) for five biomarkers known to be important in IBC (ER, PgR, c-erbB-2, p53 and Ki-67 proliferation rate) by immunohistochemistry. A comprehensive analysis of loss-of-heterozygosity (LOH) was performed in 12 cases (10 pure, 2 with synchronous IBC) at 15 genetic loci on 9 chromosomes. LCIS demonstrated a low grade/favorable biophenotype that was not significantly different in cases with and without synchronous IBC (ER 98%, PgR 84%, c-erbB-24%, p53 19% and proliferation rate 2%). LOH was present in 80% of pure LCIS and the highest rates of LOH were at loci on 9p (30%), 16q (63%), 17p (33%) and 17q (50%). The clustering of LOH at these four foci suggests that inactivated tumor suppressor genes in these regions may be particularly important. LOH was present in both cases of LCIS with synchronous IBC and the LOH phenotype was shared by LCIS and IBC. Our findings suggest that five known prognostic factors in IBC do not have prognostic utility in LCIS. Multiple genetic mechanisms may be involved in the development of LCIS.

HER2 protein overexpression in estrogen receptor-positive ductal carcinoma in situ of the breast: frequency and implications for tamoxifen therapy

Recent clinical data have suggested that the efficacy of tamoxifen in reducing the risk of local recurrence following lumpectomy and radiation therapy in patients with ductal carcinoma in situ (DCIS) is limited to patients with estrogen receptor (ER)-positive lesions. However, it is currently not known if HER2 protein overexpression might be associated with reduced tamoxifen benefit in patients with ER-positive DCIS, as has been suggested in patients with ER-positive invasive breast cancer and in preclinical models. Moreover, the frequency of HER2 overexpression in ER-positive ductal carcinoma in situ has not been previously evaluated in detail. To address this issue, we studied ER expression and HER2 overexpression in 148 cases of DCIS using a sensitive double immunostaining technique and assessed the frequency of ER expression and HER2 overexpression in relation to each other and in relation to DCIS grade. Overall, ER expression was seen in 114 cases (77%) and HER2 protein overexpression was seen in 42 cases (28%). Of 114 ER-positive ductal carcinoma in situ, 14 (12%) showed concurrent HER2 protein overexpression, and all 14 of these DCIS lesions were of high nuclear grade. In addition, in all 14 ER-positive DCIS cases that showed HER2 overexpression, double immunostaining demonstrated that ER and HER2 protein were coexpressed by the same neoplastic cells. We conclude that a subset of ER-positive DCIS show concomitant overexpression of HER2 protein. Whether or not HER2 overexpression is associated with a diminished response to tamoxifen in patients with ER-positive DCIS will require investigation in clinical outcome studies.

Estrogen receptor-negative breast carcinomas: a review of morphology and immunophenotypical analysis

Estrogen receptor (ER)-negative breast cancers are a group of tumors with poor prognosis and fewer cancer prevention and treatment strategies compared to ER-positive tumors. The aim of this study was to assess the morphological characteristics and immunohistochemical profile of ER-negative tumors and thus to understand the biological behavior and unique nature. In total, 291 consecutive ER-negative cases available from our primary breast cancer series were examined. Hematoxylin- and eosin-stained sections of all the cases were studied for several morphological parameters and their immunophenotype profile. These findings were correlated with patient and tumor characteristics and survival data. ER-negative tumors constituted 30% of the primary operable breast cancer series. The majority of tumors were grade 3 (94%) and the commonest histological types were ductal/no specific type (85%), and atypical medullary carcinoma (8%). High-grade comedo-type necrosis, lymphoid stroma, central necrosis/fibrosis and pushing margins were the most common morphological features. The presence of a pushing margin showed a significant relation to androgen receptor negativity, absence of epidermal growth factor receptor expression and negative lymph nodes. Lymphoid stroma and comedo-necrosis correlated with higher tumor grade. ER-negative breast cancers are a distinct group of tumors with several common morphological features. Grade 3 histology, pushing margin, lymphoid stroma, comedo-type necrosis and central fibrosis/necrosis are the dominant morphological findings. The presence of a pushing margin appears to have a significant correlation with negative lymph node status. ER-negative tumors show a higher expression of p53, CerbB2 and epidermal growth factor receptor compared to ER-positive breast cancer. These unique features support the concept that ER-negative tumors are a morphologically and phenotypically distinct entity and provide a rationale for the study and use of newer promising agents in the treatment of ER-negative breast cancer.

Autocrine-mediated ErbB-2 kinase activation of STAT3 is required for growth factor independence of pancreatic cancer cell lines

Pancreatic ductal adenocarcinoma (PDAC) cell lines, MIA PaCa-2, and UK Pan-1, were used to investigate the role of ErbB2 in PDAC oncogenesis. Both these cell lines exhibit exogenous growth factor-independent proliferation that was attributed to the production of autocrine growth factors and/or overexpression of growth factor receptors. The exogenous growth factor-independent phenotype displayed by these PDAC cell lines was dependent on ErbB2 kinase activity since treatment of cells with tyrphostin AG879 prevented serum-free media (SFM) induction of cell proliferation. We determined that ErbB2 kinase contributed to aberrant cell cycle regulation in PDAC through the induction of cyclin D1 levels and the suppression of p21(Cip1) and p27(Kip1). Inhibition of ErbB2 kinase led to cell cycle arrest marked by an increased association of p27(Kip1) with cdk2 and reduced levels of phosphorylated pRb. We further observed constitutive STAT3 activation in the PDAC cell lines and an increase in STAT3 activation upon stimulating quiescent cells with SFM. Inhibitors of ErbB2 kinase blocked STAT3 activation, whereas inhibition of EGFR kinase led to a slight reduction of STAT3 activation. STAT3 was coimmunoprecipitated with ErbB2. SFM stimulation caused an increase in the association of ErbB2 and STAT3, which was blocked by inhibition of ErbB2 kinase. Expression of a STAT3 dominant negative prevented SFM-stimulated cell proliferation of MIA PaCa-2 cells, suggesting that activation of STAT3 by ErbB2 is required for a growth factor-independent phenotype of these cells. Consistent with this observation in PDAC cell lines, we found that most PDAC tumor specimens (10 of 11) showed constitutive activation of STAT3 and that ErbB2 was readily detected in most of these tumors (nine of 11). We believe that these findings indicate a novel mechanism of oncogenesis in PDAC and may suggest future therapeutic strategies in the treatment of PDAC.

Molecular evolutionary patterns in breast cancer

Geno-phenotypic patterns of pre-invasive and invasive lobular breast cancers and infiltrating ductal carcinomas of low, intermediate, and high grade are reviewed. One of the main differences between lobular breast cancers and ductal carcinomas is the presence of inactivating E-cadherin gene mutations in lobular breast cancers. In many other respects, lobular breast cancers and low-grade ductal carcinomas exhibit similar geno-phenotypic profiles. The development of p53 dysfunction may be a hallmark of infiltrating ductal cancers of intermediate and high grade. Sequential Her-2/neu and ras abnormalities define a subset of aggressive high-grade tumors, and the development of Rb dysfunction may define a separate subset of aggressive ductal cancers. Based on these observations, a branching molecular evolutionary model for the development and progression of breast cancer is proposed.

HER-2/neu gene copy number quantified by real-time PCR: comparison of gene amplification, heterozygosity, and immunohistochemical status in breast cancer tissue

BACKGROUND

Amplification of the oncogene HER-2/neu influences breast cancer pathogenesis, and therapy and prognosis may be affected by the degree of amplification. The extent of amplification or protein overexpression typically is analyzed by fluorescence in situ hybridization or immunohistochemistry (IHC), but quantitative PCR techniques have been described that may provide alternatives to these methods.

METHODS

We developed a rapid-cycle, real-time PCR assay for quantification of HER-2/neu gene status. We compared results obtained with this assay with short tandem repeat findings by capillary electrophoresis (CE) and with protein overexpression assessments by IHC. Accuracy and linearity were tested on cell lines and with simulation experiments. We analyzed the amplification of HER-2/neu in 51 clinical tissue samples from patients with suspected breast cancer.

RESULTS

The intra- and interrun CVs for HER-2/neu quantification by real-time PCR were 12% and 18%, and the CV for different simulated amplification and deletion experiments was <7%. The results for HER-2/neu gene status in cell lines matched the values reported in literature. We detected HER-2/neu amplification by real-time PCR in 11 samples, all from patients with invasive ductal carcinoma. Allelic imbalances were found by CE analyses in three samples and by protein overexpression in six samples; five of these were also detected by real-time PCR. Comparison of the quantification results with known prognostic indices yielded results similar to those reported in several other published studies.

CONCLUSIONS

The assay is suitable for accurate and precise quantification of HER-2/neu copy numbers in tumor tissue samples obtained in routine clinical practice.

Morphologic spectrum of estrogen receptor-negative breast carcinoma

CONTEXT

Estrogen receptor (ER)-negative breast carcinomas are a heterogeneous group of breast cancers that are generally thought to be aggressive.

OBJECTIVE

To determine the morphologic and immunohistochemical spectrum of a consecutive series of ER-negative breast carcinomas, in an attempt to understand the pathogenesis and behavior of these lesions.

DESIGN

Seventy-four consecutive cases of ER-negative invasive carcinomas were studied. Hematoxylin-eosin-stained sections were reviewed, and new sections were stained for c-erbB-2, p53, vimentin, and androgen and prolactin receptors. The findings were correlated with the axillary lymph node status as a measure of tumor aggressiveness.

SETTING

The histopathology department of a tertiary referral teaching hospital.

RESULTS

The tumors included 50 (68%) invasive ductal carcinomas, 21 (28%) medullary/atypical medullary carcinomas, and 1 each of invasive lobular, apocrine, and papillary carcinoma. Some of the invasive ductal cases had distinctive features that are described in this report. Maximum tumor diameter varied between 5 and 100 mm. Sixty tumors (81%) were grade 3, 13 (18%) were grade 2, and 1 (1%) was grade 1. Of the 60 cases in which the axillary node status was known, 34 (57%) had metastases, and 26 did not. Tumors associated with positive nodes were significantly larger than those associated with negative nodes (37.2 vs 17.8 mm, P <.001). A higher percentage of node-negative tumors were c-erbB-2 positive (42% vs 21%, P <.05). There were no differences between the 2 groups with regard to histologic type, tumor grade, or the expression of p53, vimentin, or androgen or prolactin receptors.

CONCLUSIONS

Many ER-negative breast carcinomas have distinctive microscopic features. Not all ER-negative tumors are aggressive, as judged by the absence of lymph node metastases in 43% of cases in this series. Tumor size is the most important indicator for the likelihood of the presence of lymph node metastases. The wide range of tumor sizes encountered in this series suggests that the ER status of a tumor is determined early in its natural history and supports the existence of 2 separate pathways for the development of ER-negative and ER-positive breast carcinomas.

Tumour markers in breast carcinoma correlate with grade rather than with invasiveness

Ductal breast carcinoma in situ (DCIS) is regarded as a precursor to invasive breast cancer. The progression from in situ to invasive cancer is however little understood. We compared some tumour markers in invasive and in situ breast carcinomas trying to find steps in this progression. We designed a semi-experimental setting and compared histopathological grading and tumour marker expression in pure DCIS (n = 194), small invasive lesions (n = 127) and lesions with both an invasive and in situ component (n = 305). Grading was done according to the Elston-Ellis and EORTC classification systems, respectively. Immunohistochemical staining was conducted for p53, c-erbB-2, Ki-67, ER, PR, bcl-2 and angiogenesis. All markers correlated with grade rather than with invasiveness. No marker was clearly associated with the progression from in situ to invasiveness. The expression of tumour markers was almost identical in the 2 components of mixed lesions. DCIS as a group showed a more 'malignant picture' than invasive cancer according to the markers, probably, due to a higher proportion of poorly differentiated lesions. The step between in situ and invasive cancer seems to occur independently of tumour grade. The results suggest that well-differentiated DCIS progress to well-differentiated invasive cancer and poorly differentiated DCIS progress to poorly differentiated invasive cancer.

Pathobiologic findings in DCIS of the breast: morphologic features, angiogenesis, HER-2/neu and hormone receptors

With the increasing incidence of ductal carcinoma in situ (DCIS) of the breast and its relationship to invasive breast carcinoma, it is important to understand the biology of this entity. We report on a hospital-based survey of 219 case subjects with DCIS of the breast without associated invasive carcinoma diagnosed between 1982 and 1994. The cases of DCIS were analyzed for architectural type, size, nuclear grade, necrosis, calcification, periductal fibrosis, neovascularization, estrogen receptor (ER), progesterone receptor (PR), and HER-2/neu expression. Periductal neovascularization was associated with tumor size, microcalcifications, periductal fibrosis, and HER-2/neu overexpression. Expression of ER and PR was observed in 60 and 62% of the cases, respectively, and HER-2/neu overexpression in 28% of the cases. ER and PR expression were both inversely associated with comedo histology and nuclear grade. HER-2/neu overexpression was positively associated with comedo histology, high nuclear grade, and periductal neovascularization and was inversely correlated with both ER and PR expression. High nuclear grade was positively associated with comedocarcinoma, necrosis, microcalcification, and periductal fibrosis. The role of these molecular/pathologic markers in the biology of DCIS and their potential clinical implications are discussed.

Loss of chromosome 16q in lobular carcinoma in situ

Lobular carcinoma in situ (LCIS) and infiltrating lobular carcinoma may represent different forms of the same disease based on their frequent clinical association and similar histologic features. Patients with LCIS are at increased risk of multicentric and bilateral disease. Thus, LCIS may represent both a precursor to infiltrating lobular carcinoma and a marker of risk for breast cancer. To identify genomic alterations in LCIS, comparative genomic hybridization was performed on 17 cases without concurrent invasive carcinoma. Loss involving chromosome 16q was present in 88% of cases and was the sole detected alteration in 29%. Gain involving 1q was second in frequency, occurring in 41% of tumors, and in all cases was associated with loss of 16q. Other recurrent changes were loss involving 17p (18%), 8p (12%), and 12q24 (12%). E-cadherin immunohistochemistry was performed on all LCIS cases to evaluate the correlation of loss involving 16q22, the site of the E-cadherin gene, and altered protein expression. Most cases with 16q22 loss showed altered E-cadherin expression (12 of 13). These results in LCIS are similar to changes reported in infiltrating lobular cancer, confirming a genetic relationship between them. HUM PATHOL 32:292-296.

In microdissected ductal carcinoma in situ, HER-2/neu amplification, but not p53 mutation, is associated with high nuclear grade and comedo histology

BACKGROUND

HER-2/neu and p53 are two molecular markers that have been the focus of investigation in patients with invasive breast carcinoma. However, most of the published data have relied on immunohistochemical detection of the proteins as a surrogate marker of the underlying genetic alterations, a detection method that often gives variable results due to technical factors. In addition, there are limited data documenting HER-2/neu amplification and p53 mutations in the various histologic subtypes of ductal carcinoma in situ (DCIS). The authors evaluated a series of microdissected, pure DCIS lesions comprising a spectrum of morphologic subtypes (comedo, micropapillary, papillary, cribriform, and solid) and their corresponding normal breast tissue for genetic aberrations in HER-2/neu and p53.

METHODS

HER-2/neu amplification was determined by differential polymerase chain reaction, and p53 mutations were identified by single-strand conformation polymorphism analysis.

RESULTS

HER-2/neu amplification was identified in 12 of 30 DCIS samples (40%), and p53 mutations were identified in 6 of 30 DCIS samples (20%). The genetic alterations were not present in any of the normal breast tissue samples. HER-2/neu amplification occurred predominantly in the comedo subtype (69% vs. 18% of the noncomedo subtype; P = 0.008) and in lesions of high nuclear grade (63% vs. 14% of low grade; P = 0.01). There was no difference in the frequency of p53 mutations among the subtypes or between low grade and high grade lesions. No correlation between the presence of the two genetic alterations was observed.

CONCLUSIONS

The presence of HER-2/neu amplification, but not p53 mutations, correlates with histologic subtype and nuclear grade. The relatively frequent occurrence of HER-2/neu amplification and p53 mutations in DCIS tissue and their absence in normal breast tissue suggest that these genetic aberrations are important early in breast duct carcinogenesis.

Biological features of premalignant disease in the human breast

Most human invasive breast cancers (IBCs) arise from preexisting benign lesions. There are many types of benign lesions in the human breast and only a few appear to have significant premalignant potential (atypical hyperplasias and in situ carcinomas). These lesions are relatively common and only a small proportion progress to IBC. They are currently defined by their histological features and their prognosis is imprecisely estimated from indirect evidence based on epidemiological studies. Although lesions within specific categories look alike, they must possess morphologically silent biological differences motivating some to remain stable and others to progress. Understanding the biological changes responsible for the development and progression of premalignant disease is a very active area of medical research. Progress in this area may provide new opportunities for breast cancer prevention by providing strategies to treat premalignant lesions before they develop or become cancerous. A large number of biological features have been evaluated in this setting during the past decade. This review discusses a few features that appear to be particularly important and have been studied in a relatively comprehensive manner.

Oncogenes and male breast carcinoma: c-erbB-2 and p53 coexpression predicts a poor survival

PURPOSE

To investigate the prognostic value of biomarkers in male breast carcinoma (MBC).

PATIENTS AND METHODS

Fifty patients (mean age, 62.2 years) with invasive ductal carcinoma were retrospectively studied. All patients received surgery; 35 had adjuvant postoperative therapy. The median follow-up was 59 months (range, 1 to 230 months). c-myc, c-erbB-2, p53, and bcl-2 proteins were immunohistochemically detected on sections from formalin-fixed, paraffin-embedded tissues using 9E11, CB11, DO7, and bcl-2 124 monoclonal antibodies (mAbs). Estrogen, progesterone, and androgen receptors were detected using specific mAbs. Cell proliferation was assessed by MIB-1 mAb.

RESULTS

In univariate analysis, c-myc, c-erbB-2, and p53 protein overexpression was significantly correlated with prognosis. The median survival was 107 months for c-myc-negative and 52 months for c-myc-positive patients (P =.01), 96 months for c-erbB-2-negative and 39 months for c-erbB-2-positive patients (P =.02), and 100 months for p53-negative and 33 months for p53-positive patients (P =.0008). Tumor histologic grade (P =.01), tumor size (P =.02), patient age at diagnosis (P =.03), and MIB-1 scores (P =.0004) also had prognostic value. In multivariate analysis, only c-erbB-2 and p53 immunoreactivity retained independent prognostic significance. All nine patients who did not express c-erbB-2 and p53 proteins were alive after 58 months, whereas none of the 14 patients expressing both proteins survived at 61 months follow-up (P =.0002).

CONCLUSION

Overexpression of c-myc, c-erbB-2, and p53 proteins may be regarded as an additional prognostic factor in MBC. The combination of c-erbB-2 and p53 immunoreactivity can stratify patients into different risk groups.

Ductal carcinoma in situ. Implications for screening mammography

Ductal carcinoma in situ (DCIS) now represents 20% of all newly diagnosed breast cancers because of increased detection by screening mammography. Twenty year relative survival rates are 97%. Postsurgical and histological studies and recent molecular biological studies indicate that most cases of DCIS will progress to invasive carcinoma if not detected by mammography. Screening mammography studies support the need for annual versus less frequent screenings to detect DCIS before further progression.

Ductal carcinoma in situ (DCIS) of the breast: evolving perspectives

Ductal carcinoma in situ (DCIS) of the breast is an early, localized stage of carcinoma in the process of multistep breast carcinogenesis. The incidence of DCIS is increasing, mainly due to screening mammography, which results in diagnosing the disease in an increasing proportion of asymptomatic patients. Consequently, clinicians are being confronted with growing numbers of women who present with DCIS of the breast; thus, the concepts of managing such patients are assuming greater importance. The most common presentation is calcifications on mammography. DCIS is a biologically and morphologically heterogeneous disease. If left untreated, a significant proportion of these tumours will evolve into invasive cancer. However, when appropriately treated, the prognosis of DCIS is excellent. Optimal management of DCIS remains controversial. The goal in the treatment of patients with DCIS is to control local disease and prevent subsequent development of invasive cancer. For several decades, total mastectomy was the treatment of choice for DCIS and it should still be considered the standard of care, to which more conservative forms of treatment must be compared. Mastectomy is associated with a risk for chest wall recurrence of approximately 1%. Axillary lymph node dissection is not routinely recommended in the management of DCIS. However, mastectomy probably represents overtreatment in a substantial number of patients, especially those with small, mammographically detected lesions. Local excision alone has been suggested in carefully selected patients, whilst the rest of the patients undergoing breast-conservation surgery should be treated with breast irradiation. There is evidence that breast-conservation therapy is an effective option in the management of selected patients with DCIS. The use of radiotherapy after lumpectomy significantly decreases the rate of recurrence. Nuclear grade, presence of comedo necrosis, and margin involvement are the most commonly used predictors of the likelihood of recurrence. 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; tamoxifen should be given only in patients enrolled in clinical trials. Following breast-conservation therapy, about 50% of the tumours recur as invasive cancer. Most patients with recurrent disease can be treated effectively, usually by salvage mastectomy, but also in selected cases by breast-conservation therapy.

The prognostic value of p53 and c-erb B-2 immunostaining is overrated for patients with lymph node negative breast carcinoma: a multivariate analysis of prognostic factors in 613 patients with a follow-up of 14-30 years

BACKGROUND

Approximately 30% of breast carcinoma patients with negative lymph nodes die of their disease. Biologic markers such p53 protein and c-erb B-2 have been related to tumor progression, but their prognostic value remains controversial.

METHODS

Two large series of a total of 613 lymph node negative breast carcinoma patients from a single institution were analyzed with respect to tumor size, histologic grade, and immunohistochemical staining for p53, c-erb B-2, estrogen receptor (ER), and progesterone receptor (PgR). Interobserver variation in histologic grading was evaluated by Kappa statistics. The two series had different treatment modalities: 228 patients (SACGS group) were treated surgically with mastectomy and given 1 perioperative chemotherapy course, and 385 patients (HOST group) were treated with mastectomy and ovarian radiation and further randomized to receive postoperative treatment with radiotherapy or no adjuvant treatment. The follow-up ranged from 14-30 years.

RESULTS

Immunoreactivities for p53, c-erb B-2, ER, and PgR did not differ significantly in the two series. p53 immunostaining was present in 187 of 613 tumors (29%), and c-erb B-2 immunoreactivity was present in 58 of the tumors (10%). Three hundred forty-eight tumors (57%) were positive for ER. Kappa statistics value of interobserver variation in the histologic grading of ductal carcinomas was 0.69, which is considered to be a substantial degree of agreement. No significant differences in survival were found when comparing p53, c-erb B-2, ER, and PgR positive and negative cases. However, both recurrence free survival rates and overall survival rates after 10 years were significantly better in the T1N0M0 group compared with the T2N0M0 group (81% vs. 67% [P < 0.0001] and 85% vs. 70% [P < 0.0001]). Ten-year recurrence free survival rates for patients with histologic Grade 1 versus Grades 2-3 (according to Elston and Ellis' modification of the Bloom and Richardson method) tumors were 90% and 70%, respectively (P < 0. 0001), and overall survival rates for the same groups were 94% and 81%, respectively (P=0.0002). After 30 years of follow-up, the overall survival rate for patients with tumors of histologic Grade 1 versus Grades 2-3 were 87% and 68%, respectively, and were 78% and 66%, respectively, for patients with tumors </= 2 mm versus those with tumors > 20-50 mm. Approximately 35% of the patients with tumors of histologic Grades 2-3 and measuring > 20 mm were dead after 10 years of follow-up, contrary to 6% of the patients with tumors of histologic Grade 1 measuring </= 20 mm. A significantly more favorable prognosis also was observed in patients in the HOST group treated with adjuvant radiotherapy.

CONCLUSIONS

Histologic grade and tumor size were found to be major prognostic factors for patients after 30 years of follow-up. c-erb B-2 and p53 immunostaining does not appear have any independent prognostic value. Adjuvant radiotherapy may be of value in the treatment of patients with localized tumors.

Fluorescence in situ hybridisation detection of erbB2 amplification in breast cancer fine needle aspirates

AIM

To develop a method for the detection of amplification of the erbB2 oncogene in breast cancer fine needle aspirates using fluorescence in situ hybridisation (FISH) and to compare amplification with immunohistochemical detection of the erbB2 protein.

METHODS

A digoxigenin labelled probe to the erbB2 gene was hybridised to 15 aspirates prepared from operative breast cancer specimens. A chromosome 17 centromere probe was also hybridised to the aspirates either separately or in combination with the erbB2 probe. The aspirates were scored for erbB2 amplification and chromosome 17 centromere number. Subsequently, paraffin wax embedded sections of the tumours were stained with the antibody CB11 and scored for the presence of membrane staining.

RESULTS

Three of the 15 tumour aspirates showed high level amplification of erbB2 detected by FISH. These three tumours also showed chromosome 17 polysomy and diffuse membrane staining by immunohistochemistry.

CONCLUSIONS

FISH can be used to detect erbB2 amplification in fine needle aspirates and results correlate with conventional immunohistochemical staining. Difficulties were encountered in the visualisation of the signals in non-amplified cases without the use of specialised digital imaging.