Immunohistochemical detection of HER2/neu in patients with axillary lymph node negative breast carcinoma. A study of epidemiologic risk factors, histologic features, and prognosis

Detection of ERBB2 and CEN17 signals in fluorescent in situ hybridization and dual in situ hybridization for guiding breast cancer HER2 target therapy

The overexpression of the human epidermal growth factor receptor 2 (HER2) is a predictive biomarker in therapeutic effects for metastatic breast cancer. Accurate HER2 testing is critical for determining the most suitable treatment for patients. Fluorescent in situ hybridization (FISH) and dual in situ hybridization (DISH) have been recognized as FDA-approved methods to determine HER2 overexpression. However, analysis of HER2 overexpression is challenging. Firstly, the boundaries of cells are often unclear and blurry, with large variations in cell shapes and signals, making it challenging to identify the precise areas of HER2-related cells. Secondly, the use of sparsely labeled data, where some unlabeled HER2-related cells are classified as background, can significantly confuse fully supervised AI learning and result in unsatisfactory model outcomes. In this study, we present a weakly supervised Cascade R-CNN (W-CRCNN) model to automatically detect HER2 overexpression in HER2 DISH and FISH images acquired from clinical breast cancer samples. The experimental results demonstrate that the proposed W-CRCNN achieves excellent results in identification of HER2 amplification in three datasets, including two DISH datasets and a FISH dataset. For the FISH dataset, the proposed W-CRCNN achieves an accuracy of 0.970±0.022, precision of 0.974±0.028, recall of 0.917±0.065, F1-score of 0.943±0.042 and Jaccard Index of 0.899±0.073. For DISH datasets, the proposed W-CRCNN achieves an accuracy of 0.971±0.024, precision of 0.969±0.015, recall of 0.925±0.020, F1-score of 0.947±0.036 and Jaccard Index of 0.884±0.103 for dataset 1, and an accuracy of 0.978±0.011, precision of 0.975±0.011, recall of 0.918±0.038, F1-score of 0.946±0.030 and Jaccard Index of 0.884±0.052 for dataset 2, respectively. In comparison with the benchmark methods, the proposed W-CRCNN significantly outperforms all the benchmark approaches in identification of HER2 overexpression in FISH and DISH datasets (p<0.05). With the high degree of accuracy, precision and recall , the results show that the proposed method in DISH analysis for assessment of HER2 overexpression in breast cancer patients has significant potential to assist precision medicine.

Relationship between lymphovascular invasion and molecular subtypes in invasive breast cancer

PURPOSE

The aim of this study is to evaluate the relation between LVI and molecular subtypes in invasive breast cancers and to find out whether LVI which is a histopathologic indicator has a role in subtype classification or not.

METHODS

One hundred and seventy-six patients who had mastectomy for breast cancer between 2013 and 2018 in the Department of Surgical Oncology, Faculty of Medicine, Ankara University were retrospectively analysed. One hundred and thirty-two patients who had LVI, ER, PR, Her 2 and Ki-67 index status information provided in their pathology results were included in the study. The relationship between molecular subtypes and LVI was investigated.

RESULTS

One hundred and thirty-two patients were analysed retrospectively. Eighty-two patients had LVI and 50 patients had not. We found a relationship between Luminal B with Her2(-) and LVI, basal like and LVI (P = .00). No significant statistical difference was found between LVI and other molecular subtypes. We confirmed these results with multiple variable analysis (%77.3 correlation).

CONCLUSIONS

As a result, we found that LVI can affect molecular subtypes. This showed that a histopathological factor may affect tumour biology. In other words, breast cancer is a heterogeneous disease with many different predictors and prognostic variables.

Correlation of prognostic factors with MRI findings in malignant breast lesions

Background

Magnetic resonance imaging (MRI) of the breast represents the most sensitive imaging modality in the detection of breast cancer, with a reported sensitivity between 94 and 100%. We aim to detect the correlation between MRI findings and pathologically detected prognostic factors in malignant breast lesions.

Breast parenchymal density distribution, background parenchymal enhancement pattern, lesion’s morphologic features, T2WI signal characteristics, contrast enhancement, time/signal intensity curves, and lesions localizations in breast were evaluated using dynamic MRI images. Histopathological diagnosis, maximum measurements of the lesion, histological grade, presence of estrogen and/or progesterone receptors, c-erb B2, and Ki-67 parameters were noted as prognostic factors.

Results

We cannot detect any relationship between the breast parenchymal density and prognostic factors. Mild background breast enhancement is related with ER presence, a good prognostic factor. Histopathological grade of the lesions augmented with the increase in the lesion diameters. ADC values are not related with prognostic factors.

Conclusion

A mild background enhancement, an intermediate signal intensity on T2WI, a high tpeak value, and absence of pathological axillary lymph node are found to be related with good prognostic factors. An irregular contour, a huge diameter, having a type III kinetic curve, a high slopei value, and presence of pathological axillary lymph node are found to be related with poor prognostic factors. MRI can be used to predict prognostic factors in breast cancer cases.

Frequency, Clinicopathologic Characteristics, and Follow-up of HER2-Positive Nonpleomorphic Invasive Lobular Carcinoma of the Breast

OBJECTIVES

To investigate human epidermal growth factor receptor 2 (HER2)-positive nonpleomorphic invasive lobular carcinoma (ILC), which has rarely been addressed.

METHODS

Clinicopathologic characteristics and follow-up of HER2-positive nonpleomorphic ILCs were collected and compared to those of HER2-negative counterparts.

RESULTS

Twenty-one cases of HER2-positive nonpleomorphic ILCs were identified, 6.3% of the study population. Compared to HER2-negative nonpleomorphic ILC, patients with HER2 positivity were older (P < .05), likely to be hormonal receptor negative (P < .01), and had higher histologic grade and angiolymphatic invasion (P < .01). HER2 positivity in nonpleomorphic ILCs was associated with higher recurrence/metastasis with hazard ratio of 2.03 (P < .05). No patient who received neoadjuvant therapy achieved pathologic complete response, and HER2-targeted therapy tended to reduce recurrence/metastasis in patients with HER2-positive nonpleomorphic ILC.

CONCLUSIONS

Our results highlight the existence of HER2 positivity in nonpleomorphic ILCs and reinforce that HER2 is associated with worse prognosis in nonpleomorphic ILC.

The Prognostic Value of p53 and c-erbB-2 Expression, Proliferative Activity and Angiogenesis in Node-Negative Breast Carcinoma

Aims and background

p53, c-erbB-2 and Ki-67 protein expression and microvessel density (MVD) determined by CD34 antibody were evaluated by immunohistochemistry and their correlation with clinicopathological parameters including estrogen (ER) and progesterone (PR) receptor status and survival were investigated in patients with axillary lymph node-negative infiltrating ductal breast carcinoma.

Methods

The study population consisted of 47 patients with axillary lymph node-negative infiltrating ductal breast carcinoma.

Results

p53 and c-erbB-2 expression was detected in 36.2% and 31.9% of patients, respectively. Median Ki-67 expression was 10%. There were no statistically significant differences in the distribution of p53, Ki-67 and c-erbB-2 protein expression in relation to the age of the patients or to the size, histological grade or ER and PR status of the tumors. p53 protein expression correlated positively with c-erbB-2 and Ki-67 protein expression (P <0.05). The mean MVD was 63.65 ± 29.1 and it correlated positively with histological grade and Ki-67 expression (P <0.05). Survival analysis revealed that age, tumor size, p53 and c-erbB-2 expression and PR status had no significant prognostic impact, whereas histological grade, proliferative activity and angiogenic activity were significant prognostic factors. Although ER-positive patients had a statistically significant overall survival advantage, the difference in disease-free survival was not significant.

Conclusion

In axillary lymph node-negative breast carcinoma the histological grade and the proliferative and angiogenic activity of the tumor could be useful prognostic indicators.

Her-2/neu overexpression in breast cancers in patients of West African extraction seen in Lagos state University Teaching hospital, Nigeria

INTRODUCTION

Her-2/neu is one of the most important molecular markers of breast cancer. Overexpression of Her-2/neu as evaluated by immunohistochemistry is necessary in the management of breast cancers. This study was performed to determine the proportion of expression of the biomarker amongst breast cancer patients who presented in our 'one-stop breast cancer unit' using automated immunohistochemistry.

MATERIALS AND METHODS

Automated immunohistochemical analysis of 107 newly diagnosed breast cancer patients was done for expression of Her-2/neu, between 1st April, 2016 and 30th September, 2018. The data was analyzed using SPSS version 25 for windows and Microsoft excel, 2013.

RESULTS

Her-2/neu was overexpressed in 30.1% patients, and it shows no correlation with age and histological grade of the disease.

CONCLUSION

There is overexpression of Her-2/neu in our local setting, and this observation is very relevant to any therapeutic decisions and management of these patients.

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.

Prognostic Role of Adjuvant Chemotherapy in Node-Negative (N0), Triple-Negative (TN), Medullary Breast Cancer (MBC) in the Korean Population

BACKGROUND

Despite the favorable prognosis for medullary breast cancer (MBC), the guidelines for the use of adjuvant chemotherapy for MBC have not been clearly established. This study investigated the prognostic role of adjuvant chemotherapy in Korean patients with node-negative (N0), triple-negative (TN) MBC patients.

METHODS

We included data from 252 patients with N0 TN MBC, obtained from the Korean Breast Cancer Registry database. Patients were categorized as those who did not undergo adjuvant chemotherapy (group I) or those who did (group II). Clinicopathological characteristics, breast cancer-specific survival (BCSS), and overall survival (OS) were compared between the groups. In addition, a subgroup analysis for survival based on tumor size was conducted.

RESULTS

A total of 252 N0 TN MBC patients with tumor sizes >1 cm who were diagnosed between April 1997 and March 2011 were enrolled. The median age was 44.95 years (range, 25-72 years), and the median follow-up period was 93.94 months (range, 23-195 months). Overall, the BCSS and OS in group II (97.3% and 97.3%, respectively) were significantly better compared with those in group I (89.2% and 86.2%, respectively). In the subgroup analysis, in patients with tumors >2 cm in size, those in group II had significant better BCSS and OS (97.5% and 97.5%, respectively) compared with those in group I (78.3% and 73.9%, respectively). In contrast in those with tumors 1-2 cm in size, there were no significant differences in BCSS and OS between the groups (both 97.1% for group I, and 95.2% and 92.9%, respectively for group II). Multivariate analysis revealed that adjuvant chemotherapy significantly improved BCSS (P = 0.009) and OS (P = 0.007), but only for patients with larger tumors (>2 cm).

CONCLUSIONS

In patients with N0 TN MBC, adjuvant chemotherapy had a significant clinical survival benefit, but only in those with tumors >2 cm.

Clinicopathologic characteristics of typical medullary breast carcinoma: a retrospective study of 117 cases

PURPOSE

This study analyzed the clinicopathologic characteristics of typical medullary breast carcinoma (TMBC) in a cohort of Chinese patients.

METHODS

We conducted a retrospective review of clinical data including general information, pathologic results, treatment regimens, and patient survival in cases of TMBC diagnosed between February 2004 and April 2011.

RESULTS

A total of 117 patients were enrolled, with a median age of 52 years (range, 28∼92 years). Stage I and II disease accounted for 31.6% and 61.6% of the cases, respectively. Hormonal receptor negative disease (estrogen receptor negative, 68.4%; progestogen receptor negative, 86.3%) was more prevalent in this population. Human epidermal growth factor receptor-2 (HER-2) positivity was 20.5%, while equivocal and HER-2 negative cases represented 16.2% and 63.2% of the cohort. The triple-negative, luminal, and HER-2 overexpressing subtypes constituted 44.4%, 31.6%, and 15.4% of the cases, respectively. The various TMBC subtypes showed no differences regarding tumor size, rates of lymph node(s) metastasis, TNM staging, treatment regimens, and 2-year recurrence rates. However, patients with triple-negative disease were more likely to be younger, when compared to those with luminal disease (P = 0.002). At a median follow-up of 56 months (range, 2-112 months), the 2-year disease-free survival and overall survival rates were 99.1% and 98.2%, respectively.

CONCLUSION

Early stage disease dominated the study cohort, and at two years after surgery, recurrence was extremely low. The heterogeneity of molecular subtypes was clearly shown, and no apparent differences were found among the clinicopathologic characteristics of the triple-negative, luminal, and HER-2 overexpressing subtypes.

Epigenetic silencing of miR-375 induces trastuzumab resistance in HER2-positive breast cancer by targeting IGF1R

BACKGROUND

Resistance to humanized monoclonal erbB2/HER2 antibody, trastuzumab (Herceptin), has become a pivotal obstacle for targeted therapy of HER2-positive breast cancers. The activation of alternative growth factor receptors, in particular, the insulin-like growth factor 1 receptor (IGF1R), represents a common feature of trastuzumab-refractory cells; however, the underlying mechanism remains elusive.

METHODS

Trastuzumab-resistant breast cancer SKBr-3 cells were generated by long-term in vitro culture of SKBr-3 cells in the presence of trastuzumab. Among the differentially expressed microRNAs (miRNAs) screened by microarray analysis, candidate miRNA(s) predicted to target IGF1R was studied for its role in conferring trastuzumab resistance. The mechanism underlying decreased expression of IGF1R-targeted miRNA in refractory cells was also addressed.

RESULTS

miR-375, which was downregulated and predicted to target IGF1R in trastuzumab-resistant HER2-positive breast cancer cells, could indeed inhibit the cellular luciferase activity in a reporter construct containing the 3'-UTR of IGF1R. Overexpression of miR-375 restored the sensitivity of cells to trastuzumab, while inhibition of miR-375 conferred trastuzumab resistance on HER2-positive breast cancer cells. Blockade of DNA methylation and histone deacetylation restored the expression of miR-375 in trastuzumab-resistant cells. A reverse correlation between the levels of miR-375 and IGF1R was validated in clinical breast cancers.

CONCLUSIONS

Epigenetic silencing of miR-375 causes the upregulation of IGF1R, which at least partially underlies trastuzumab resistance of breast cancer cells. Our study has implications for miR-375 as a potential target in combination with trastuzumab for treating HER2-positive breast cancers.

Prognosis of medullary breast cancer: analysis of 13 International Breast Cancer Study Group (IBCSG) trials

BACKGROUND

To evaluate whether medullary breast cancer has a better prognosis compared with invasive ductal tumors.

METHODS

Among 12,409 patients, 127 were recorded as invasive medullary tumors and 8096 invasive ductal tumors. Medullary and ductal invasive tumors were compared with regard to stage, age at diagnosis, grade, hormone receptor status, peritumoral vascular invasion, and local and systemic treatment. Pattern of relapse, distant recurrence-free interval (DRFI), and overall survival (OS) were determined for both histological groups. Two cohorts were investigated: a full cohort including the pathologist-determined medullary histology without regard to any other tumor features and a cohort restricted to patients with ER-negative grade 3 tumors.

RESULTS

Fourteen-year DRFI and OS percents for medullary tumors (n = 127) and invasive ductal tumors (n = 8096) of the full cohort were 76% and 64% [hazard ratio (HR) 0.52, P = 0.0005] and 66% and 57% (HR = 0.75, P = 0.03), respectively. For the restricted cohort, 14-year DRFI and OS percents for the medullary (n = 47) and invasive ductal tumors (n = 1407) were 89% and 63% (HR 0.24, P = 0.002) and 74% and 54% (HR = 0.55, P = 0.01), respectively. Competing risk analysis for DRFI favored medullary tumors (HR medullary/ductal = 0.32; 95% confidence interval = 0.13-0.78, P = 0.01).

CONCLUSION

Medullary tumors have a favorable prognosis compared with invasive ductal tumors.

Trastuzumab produces therapeutic actions by upregulating miR-26a and miR-30b in breast cancer cells

Objective

Trastuzumab has been used for the treatment of HER2-positive breast cancer (BC). However, a subset of BC patients exhibited resistance to trastuzumab therapy. Thus, clarifying the molecular mechanism of trastuzumab treatment will be beneficial to improve the treatment of HER2-positive BC patients. In this study, we identified trastuzumab-responsive microRNAs that are involved in the therapeutic effects of trastuzumab.

Methods and Results

RNA samples were obtained from HER2-positive (SKBR3 and BT474) and HER2-negetive (MCF7 and MDA-MB-231) cells with and without trastuzumab treatment for 6 days. Next, we conducted a microRNA profiling analysis using these samples to screen those microRNAs that were up- or down-regulated only in HER2-positive cells. This analysis identified miR-26a and miR-30b as trastuzumab-inducible microRNAs. Transfecting miR-26a and miR-30b induced cell growth suppression in the BC cells by 40% and 32%, respectively. A cell cycle analysis showed that these microRNAs induced G1 arrest in HER2-positive BC cells as trastuzumab did. An Annexin-V assay revealed that miR-26a but not miR-30b induced apoptosis in HER2-positive BC cells. Using the prediction algorithms for microRNA targets, we identified cyclin E2 (CCNE2) as a target gene of miR-30b. A luciferase-based reporter assay demonstrated that miR-30b post-transcriptionally reduced 27% (p = 0.005) of the gene expression by interacting with two binding sites in the 3′-UTR of CCNE2.

Conclusion

In BC cells, trastuzumab modulated the expression of a subset of microRNAs, including miR-26a and miR-30b. The upregulation of miR-30b by trastuzumab may play a biological role in trastuzumab-induced cell growth inhibition by targeting CCNE2.

Testing for HER2 in Breast Cancer: A Continuing Evolution

Human epidermal growth factor receptor 2 (HER2) is an important prognostic and predictive factor in breast cancer. HER2 is overexpressed in approximately 15%–20% of invasive breast carcinomas and is associated with earlier recurrence, shortened disease free survival, and poor prognosis. Trastuzumab (Herceptin) a “humanized” monoclonal antibody targets the extracellular domain of HER2 and is widely used in the management of HER2 positive breast cancers. Accurate assessment of HER2 is thus critical in the management of breast cancer. The aim of this paper is to present a comprehensive review of HER2 with reference to its discovery and biology, clinical significance, prognostic value, targeted therapy, current and new testing modalities, and the interpretation guidelines and pitfalls.

FOXO1A is a target for HER2-overexpressing breast tumors

Trastuzumab treatment has improved the overall survival of HER2-overexpressing breast cancer patients. However, many of these patients will eventually become resistant to treatment. The mechanisms that contribute to resistance to trastuzumab are unknown. In this study, we tested the hypothesis that targeting of the FKHR transcription factor FOXO1A in HER2-overexpressing breast tumor cells can overcome the trastuzumab resistance in vitro. We have shown that overexpression of HER2 leads to activation of phosphatidylinositol 3-kinase (PI3K)/Akt pathway and subsequent inactivation of FOXO1A in HER2-overexpressing breast cancer cells SKBR3, BT474, and MCF7-HER2. In wild-type SKBR3 and BT474 cells, trastuzumab downregulates active Akt and increases FOXO1A expression that leads to increase in p27(kip1) and decrease in cyclin D1 and finally inhibits cell proliferation. In contrast, the effect of trastuzumab was eliminated by the reduction of FOXO1A in HER2-overexpressing cells with constitutively active Akt1 (SKBR3/AA28 and BT474/AA9). The downregulation of FOXO1A resulted in nuclear export of p27(kip1). Blocking the constitutively active Akt by a specific Akt/protein kinase B signaling inhibitor-2 (API-2) significantly increased FOXO1A expression and rendered the cells more responsive to trastuzumab-induced growth inhibition. Reactivation of FOXO1A by stable or transient transfection also restored the growth-inhibitory effects of trastuzumab in SKBR3/AA28, BT474/AA9, and MCF7-HER2 cells. Knocking down FOXO1A by small interfering RNA resulted in reducing trastuzumab-induced growth inhibition. In summary, trastuzumab can inhibit proliferation of HER2-overexpressing breast cancer cells by reactivating FOXO1A through inhibition of the PI3K/Akt pathway. FOXO1A may therefore serve as a target for HER2-overexpressing breast tumors.

The HER-2 receptor and breast cancer: ten years of targeted anti-HER-2 therapy and personalized medicine

The human epidermal growth factor receptor (HER-2) oncogene encodes a transmembrane tyrosine kinase receptor that has evolved as a major classifier of invasive breast cancer and target of therapy for the disease. The validation of the general prognostic significance of HER-2 gene amplification and protein overexpression in the absence of anti-HER-2 targeted therapy is discussed in a study of 107 published studies involving 39,730 patients, which produced an overall HER-2-positive rate of 22.2% and a mean relative risk for overall survival (OS) of 2.74. The issue of HER-2 status in primary versus metastatic breast cancer is considered along with a section on the features of metastatic HER-2-positive disease. The major marketed slide-based HER-2 testing approaches, immunohistochemistry, fluorescence in situ hybridization, and chromogenic in situ hybridization, are presented and contrasted in detail against the background of the published American Society of Clinical Oncology-College of American Pathologists guidelines for HER-2 testing. Testing issues, such as the impact of chromosome 17 polysomy and local versus central HER-2 testing, are also discussed. Emerging novel HER-2 testing techniques, including mRNA-based testing by real-time polymerase chain reaction and DNA microarray methods, HER-2 receptor dimerization, phosphorylated HER-2 receptors, and HER-2 status in circulating tumor cells, are also considered. A series of biomarkers potentially associated with resistance to trastuzumab is discussed with emphasis on the phosphatase and tensin homologue deleted on chromosome ten/Akt and insulin-like growth factor receptor pathways. The efficacy results for the more recently approved small molecule HER-1/HER-2 kinase inhibitor lapatinib are also presented along with a more limited review of markers of resistance for this agent. Additional topics in this section include combinations of both anti-HER-2 targeted therapies together as well as with novel agents including bevacizumab, everolimus, and tenespimycin. A series of novel HER-2-targeting agents is also presented, including pertuzumab, ertumaxomab, HER-2 vaccines, and recently discovered tyrosine kinase inhibitors. Biomarkers predictive of HER-2 targeted therapy toxicity are included, and the review concludes with a consideration of HER-2 status in the prediction of response to non-HER-2 targeted treatments including hormonal therapy, anthracyclines, and taxanes.

Poor survival outcomes in HER2-positive breast cancer patients with low-grade, node-negative tumours

We present a retrospective analysis on a cohort of low-grade, node-negative patients showing that human epidermal growth factor receptor 2 (HER2) status significantly affects the survival in this otherwise very good prognostic group. Our results provide support for the use of adjuvant trastuzumab in patients who are typically classified as having very good prognosis, not routinely offered standard chemotherapy, and who as such do not fit current UK prescribing guidelines for trastuzumab.

Solamargine induces apoptosis and enhances susceptibility to trastuzumab and epirubicin in breast cancer cells with low or high expression levels of HER2/neu

Trastuzumab is used for breast cancer patients with high expression levels of HER2 (human epidermal growth factor receptor 2)/neu; however, it has no effect on cancers with low levels of HER2/neu. SM (solamargine), a major steroidal alkaloid glycoside purified from Solanum incanum, triggered apoptosis of breast cancer cells (MCF-7 and SK-BR-3 cells) and non-cancerous breast epithelial cells (HBL-100 cells) within 3 h. To extend the application of trastuzumab in breast cancer patients, the regulation of HER2/neu expression by SM was investigated. SM significantly up-regulates HER2/neu expression in breast cancer cells with low and high expression levels of HER2/neu, and synergistically enhanced the effect of trastuzumab in inhibiting cell proliferation. Additionally, HER2/neu and TOP2A [TopoII (topoisomerase II) α] genes share the same amplicon on an identical chromosome. Notably, SM co-regulates HER2/neu and TopoIIα expression markedly, and enhances TopoII inhibitor–EPI (epirubicin)-induced cytotoxicity to breast cancer cells.

HER2: The Neu Prognostic Marker for Breast Cancer

A fundamental mechanism of genetic alteration is amplification of entire gene sequences that results in overexpression of a gene product or protein. If the amplified gene is a member of the oncogene family and/or a regulator of DNA replication or cell cycle progression, overexpression of this oncoprotein may result in enhanced growth advantages for these cells. Amplification of one such oncogene, HER2 (neu, erbB-2), in up to 35% of human breast cancers is associated with a poor prognosis but may predict response to various therapeutic modalities. FDA-approved assays are available to detect the HER2 protein receptor or the HER2 gene sequence to determine eligibility for Herceptin treatment or adriamycin treatment in node positive patients, respectively. As testing for HER2 is becoming more common in the clinical laboratory, we provide an overview of the biology, diagnostic methods, and emerging clinical value of HER2 gene amplification.

Prognostic significance of HER2 gene amplification according to stage of breast cancer

It is well known that the amplification of the HER2 gene is closely associated with poor prognosis of breast cancer. However, there is controversy about the clinical significance of HER2 according to lymph node status in breast cancer. The aim of this study was to identify the differences in the prognostic significance of HER2 gene amplification according to the stages of breast cancer. We prepared a tissue array for fluorescence in situ hybridization (FISH) with breast cancer specimens from the surgery in 1994 to 1999. Total 338 cases of breast cancer were enrolled and the median follow-up period was 6.3 yr. The detection rates of HER2 gene amplification were as follows: 10.3% in stage I, 22.3% in stage II, and 43.8% in stage III. On survival analyses HER2-positive groups showed worse prognosis in stage III of breast cancer, but not in stage I or II. Multivariate analyses with a Cox-regression model also revealed that HER2 amplification was an independent prognostic factor only in stage III breast cancer. Regarding HER2 gene amplification as a prognostic factor of breast cancer, the clinical significance of the gene was found to be confined to advanced breast cancer.

Immunohistochemical determination and grading of CerbB-2 expression in breast cancer: correlation with interpectoral, apical nodal involvement and other prognostic factors

We aimed to investigate the correlation between quantitative CerbB-2 expressions with conventional prognostic factors, and distinct nodal involvement in patients with invasive breast carcinoma. One hundred fifty seven consecutive breast carcinoma patients were retrospectively analysed. Level I–II, Level III, and Rotter (Interpectoral) group lymph nodes were separately examined and recorded. For each patient estrogen receptor (ER), progesteron receptor (PR), CerbB-2, P53 status were defined using immunohistochemistry. Age, tumor localisation, menopausal status, grade and the presence of intraductal component were also recorded. CerbB-2 expression did not correlate with age, localisation and menopausal status. There was a reverse, but weak correlation with tumor size and CerbB-2 expression (p=0.034). In subgroup analysis of CerbB-2 positive cases, the magnitude of CerbB-2 positivity did not correlate with tumor size (p=0.551). In univariate analysis CerbB-2 expression did not correlate with nodal involvement in Level I-II, and Rotter. In subgroup analysis of patients with positive CerbB-2, positivity of CerbB-2 linearly increased with the number of positive lymph nodes in Level I-II, and this difference was significant (p=0,039). There was a significant correlation between CerbB-2 expression and Level III nodal metastases (p=0.005). But this correlation was not significant among CerbB-2 positive patients (p=0.82). P53, PR positivity and the presence of intraductal component did not differ according to oncogene expression. We detected a reverse correlation with ER positivity and CerbB-2 positivity (p=0.011). It is concluded that quantitative expression of CerbB2 positivity increases with nodal involvement in Level I–II axillary lymph nodes, and ER. Also, CerbB-2 positivity is more common among patients with Level III lymph node metastases.

HER-2/neu in breast cancer: a comparative study between histology, immunohistochemistry, and molecular technique (FISH)

HER-2/neu is a protooncogene frequently overexpressed in breast cancer. Fluorescence in situ hybridization (FISH) is a technique targeting the gene amplification, while immunohisto-chemistry detects the protein expression. Usually both are applied to paraffin-embedded tissue. The authors studied HER-2 by FISH and immunohistochemistry (HercepTest) in 81 breast carcinomas. The results showed an overall concordance (correlation coefficient 0.64). In all cases with HercepTest score 0 and 1+, nonamplification of the gene was observed. Gene amplification was found in 20% of cases with a 2+ score and in 77.78% of cases with a 3+ score. Data described in literature for 3+ carcinomas showed a 3% to 10% discrepancy between protein expression and gene amplification, while in this study this difference was up to 22.22%. As a consequence, even if it is usually considered important to analyze only 2+ cases by FISH, 3+ scores nonamplified for HER-2/neu may be a new, interesting subset. Furthermore, the authors investigated the two-variables correlation between chromosome 17 copy number, protein over-expression, gene amplification, and presence of metastatic lymph nodes. Interesting results came from the correlation between the HercepTest score and the HER-2/neu gene amplification evaluation, HercepTest and chromosome 17 aneusomy, and gene amplification and lymph nodes status. In conclusion, the FISH technique can be an important and useful diagnostic tool to integrate the results of the HercepTest and to select patients for immunotherapy.

Central nervous system metastases in breast cancer patients administered trastuzumab

Amplification or over-expression of the HER2/neu receptor is present in 20-30% of invasive breast cancers and in 60% of intraductal breast carcinomas. Patients with HER2/neu gene aberrations have more aggressive disease, frequent disease recurrence and a shorter survival. Trastuzumab (herceptin) is a monoclonal antibody selectively directed against the HER2/neu receptor. The addition of trastuzumab to chemotherapy in HER2/neu-positive advanced breast cancer patients has increased complete and partial response rates, and prolonged time to progression and overall survival. However, a relatively common failure site in patients administered trastuzumab is the central nervous system (CNS). CNS metastases in these patients seem to develop despite responses achieved in extracerebral sites. This pattern of failure has mainly been attributed to the lack of trastuzumab penetration to the CNS owing to the high molecular weight (145 kDa) of this molecule. Additionally, increased risk of CNS relapse may be associated with improved systemic control of extracerebral metastases and prolonged survival without brain protection (a sanctuary site). Finally, it was postulated that HER2/neu over-expression and/or amplification might predispose to brain metastases. The aim of this article is to discuss the pathophysiology of this phenomenon and its clinical implications.

Purification and characterization of a single-chain chimeric anti-p185 antibody expressed by CHO-GS system

Monoclonal antibody A21 reacts specifically with the extracellular domain of p185c-erbB-2 oncoprotein, a member of the epidermal growth factor receptor family. In a previous study, we constructed a single-chain chimeric antibody, assembled using an A21 single-chain Fv antibody and a human IgG1 Fc fragment. In this study, we expressed this chimeric antibody using a CHO-GS system, and developed a simple and efficient method for its purification. After only one step using affinity purification, the recovery rate and purity of the antibody attained was 60 and 91%, respectively. After a second step, using reverse phase HPLC purification, the purity was above 99%. The high purity of the recombinant antibody allowed us to identify a number of its intrinsic molecular properties, including antigen binding activity, measurement of affinity constant, N-terminal sequencing, and mass spectrometer analysis. These results further augment the potential of this recombinant antibody to be a drug candidate for cancer therapy.

Expression of c-myc, erbB-2, p53 and nm23-H1 gene product in benign and malignant breast lesions: coexpression and correlation with clinicopathologic parameters

The aims of this study were to assess the expression of protein products of c-myc, erbB-2, p53 and nm23-H1 gene in benign and malignant breast lesions, to estimate their possible coexpression and to correlate the results of immunohistochemical analysis with various clinicopathologic parameters. The method used was the immunohistochemical detection of the corresponding protein. Expression of c-myc protein was high in both malignant and benign lesions (95% and 100%). Expression of erbB-2 and mutated p53 proteins in malignant lesions was 27% and 34%. These proteins were present in benign lesions as well: 7.8% of benign lesions were positive for erbB-2 protein and 19.6% for p53 protein. The expression of nm23-H1 protein was similar in benign and malignant lesions: 47% and 54%. The coexpression of nm23-H1 and mutated p53 protein was found in 14 carcinomas (16.5%). We found a tendency of negative correlation between the expression of these two proteins. We also found a negative correlation between the size of breast carcinomas and the expression of nm23-H1, a higher proportion of nm23-H1-positive carcinomas in the group of erbB-2-negative, p53-negative carcinomas and a higher proportion of nm23-H1-positive carcinomas in the group of malignant lesions with negative axillary lymph nodes. Our results support the hypothesis that in women with breast cancer the expression of nm23-H1 gene may contribute to more favorable phenotype. We also showed that some changes found in malignant breast tumors such as the presence of mutated p53 protein and the expression of erbB-2 protein may be found in benign lesions as well.

Correlation of the HER-2 protein expression and other clinicopathological features of ductal infiltrative breast cancer

The aim of the study was to investigate the relationship between the expression of the HER-2 membrane protein and other clinical-pathological parameters such as: histological size of the tumor, degree of the tumor's differentiation, presence of vascular invasion and presence of metastases in regional lymph nodes, in cases of ductal infiltrative breast cancer. We have investigated 56 cases of ductal infiltrative breast cancer. In all patients a mastectomy with a dissection of axillary lymph nodes has been performed. All tissue samples, taken by biopsy, were embedded in the paraffin, stained by hematoxylin-eosin technique and screened, and evaluation was performed by using a semiquantitative method of the immunohistochemical expression of the HER-2 protein. A decrease of the protein HER-2 expression was noticed in cases of an increase of the tumor's diameter above 50 mm. Increased expression of the HER-2 protein was noticed in cases of moderate (grade II) and poor (grade III) differentiation of carcinoma, as well as in cases where there was no metastases in the regional lymph nodes. No relationship has been observed between the expression of HER-2 and occurrence of vascular invasion. In cases of ductal infiltrative breast cancer the expression of HER-2 protein is in correlation with the size and degree of tumor's differentiation, as well as with the presence of metastases in regional lymph nodes.

Correlation of breast cancer risk factors with HER-2/neu protein overexpression according to menopausal and estrogen receptor status

Background

Several researchers have claimed that classification of tumours on the basis of HER-2/neu overexpression or amplification may define a subset of breast cancer in which the net effect of a risk factor could be rather more obvious and its impact on breast cancer development more clear. We decided to investigate, in a group of patients from a geographical area with a low incidence of breast cancer, whether HER-2/neu positive tumours are correlated with established or suspected risk factors for breast cancer and thus to identify distinct subgroups of high risk women.

Methods

This study analysed data from patients who attended the Breast Unit at the University Hospital of Heraklion, Crete, Greece between 1996 and 2002. 384 women with primary invasive breast cancer were compared with 566 screened women who were referred to the Unit and had not developed breast neoplasm by the time the data were analysed. Risk factor data were obtained from each subject by personal interviews using a structured questionnaire. The detection and scoring of the HER-2/neu protein, estrogen and progesterone receptor expression were performed using immunochemistry. Odds ratios and 95% confidence intervals were determined by chi-square test and logistic regression analysis. Case-case odds ratios were calculated in order to measure the risk heterogeneity between HER-2/neu+ and HER-2/neu-tumours. Separate analyses were performed for premenopausal and postmenopausal women and according to estrogen receptor status.

Results

In multivariate analysis without HER-2/neu stratification, an increased breast cancer risk was associated with only four of the factors examined: use of oral contraceptives (OR = 4.40, 95%C.I: 1.46–13.28), use of HRT (OR = 7.34, 95%C.I: 2.03–26.53), an age at first full pregnancy more than 23 years (OR = 1.91, 95%C.I: 1.29–2.83) and body mass index more than 29 kg/m² (OR = 3.13, 95%C.I: 2.02–4.84). Additionally, a history of abortion or miscarriage (OR = 0.56, 95%C.I: 0.38–0.82) was correlated with a decreased risk of breast cancer. In the case to case comparison only BMI >29 kg/m² revealed a relative connection that was stronger with positive than with negative HER-2/neu tumours (ratio of OR's = 2.23, 95%C.I: 1.20–4.15, p = 0.011). This may indicate evidence of heterogeneity of a rather significant degree for this factor. In the ER negative group an age at first full pregnancy >23 years and a BMI >29 kg/m² were associated with an increased risk in both HER-2/neu groups, but the association was significantly stronger for the latter factor in the positive HER-2/neu tumours (ratio of OR's = 2.46, 95%CI: 0.97–6.21).

Conclusions

Our study did not confirm that the established or putative hormonal breast cancer risk factors differ regarding their relations with HER-2/neu+ versus HER-2/neu-breast tumours, with the exception of increased BMI. Further innovative studies with larger sample sizes are needed to examine how the status of these potentially modifiable breast cancer risk factors interacts with biological markers such as HER-2/neu oncoprotein.

Long-term prognostic significance of HER-2/neu in untreated node-negative breast cancer depends on the method of testing

Introduction

The prognostic significance of HER-2/neu in breast cancer is a matter of controversy. We have performed a study in 101 node-negative breast cancer patients with long-term follow-up not treated in the adjuvant setting, and analysed the prognostic significance of immunohistochemistry (IHC) and fluorescence in situ hybridisation (FISH), both separately and in combination, in comparison with traditional prognostic factors.

Methods

Overexpression was classified semiquantitatively according to a score (0 to 3+) (HER-2_SCO). FISH was used to analyse HER2/neu amplification (HER-2_AMP). Patients classified 2+ by IHC were examined with FISH for amplification (HER-2_ALG). Patients with 3+ overexpression as well as amplification of HER-2/neu were positive for the combined variable HER2_COM. These variables were compared with tumour size, histological grade and hormone receptor status.

Results

HER-2_SCO was 3+ in 20% of all tumours. HER-2_ALG was positive in 22% and amplification (HER-2_AMP) was found in 17% of all tumours. Eleven percent of the tumours showed simultaneous 3+ overexpression and amplification. Only histological grade (relative risk [RR] 3.22, 95% confidence interval [CI] 1.73–5.99, P = 0.0002) and HER-2_AMP (RR 2.47, 95% CI 1.12–5.48, P = 0.026) were significant for disease-free survival in multivariate analysis. For overall survival, both histological grade (RR 3.89, 95% CI 1.77–8.55, P = 0.0007) and HER-2_AMP (RR 3.08, 95% CI 1.24–7.66, P = 0.016) retained their independent significance.

Conclusion

The prognostic significance of HER-2/neu in node-negative breast cancer depends on the method of testing: only the amplification of HER-2/neu is an independent prognostic factor for the long-term prognosis of untreated node-negative breast cancer.

HER2 amplification ratios by fluorescence in situ hybridization and correlation with immunohistochemistry in a cohort of 6556 breast cancer tissues

To analyze HER2 amplification in a large cohort of diagnostic breast cancer specimens, fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) were performed on the same specimens with use of Food and Drug Administration&approved products. Procedures were standardized following the manufacturers' recommendations. Of 116,736 IHC specimens, 20% were positive for HER2. In 16,092 FISH specimens, 22.7% showed HER2 amplification. In the subset of 6556 tissues analyzed with IHC and FISH, however, 59% were positive on IHC and 23.6% were amplified on FISH. The increased frequency of positive test results is skewed by more frequent reflex FISH testing. In general, expression and amplification trended together, with the least amplification (4.1%) seen in IHC-negative cases, 7.4% amplification seen in IHC 1+ cases, 23.3% amplification seen in IHC 2+ cases, and 91.7% amplification seen in IHC 3+ cases. When FISH amplification ratios were stratified, the low FISH ratios (2.0-2.2) were most frequently seen in specimens with negative IHC results, high ratios (>5.0) were seen in IHC 3+ specimens, and intermediate levels of amplification were similar for all levels of IHC. The effect of changing the cutoff point was analyzed: removing cases with a ratio of exactly 2.0 decreased the FISH positivity rate to 22.2% in the combined IHC and FISH cohort. Sequentially moving the cutoff point to 2.2 and 2.5 affected cases at all IHC expression levels. Each change removed approximately 2% from the apparent positivity. This large database provides the distribution frequency of HER2 protein expression and gene amplification in invasive ductal and lobular breast cancer. The relationship between level of HER2 amplification and clinical outcome will require reanalysis of pivotal trial data.

Infiltrating lobular carcinoma of the breast: tumor characteristics and clinical outcome

INTRODUCTION

Invasive lobular carcinoma (ILC) comprises approximately 10% of breast cancers and appears to have a distinct biology. Because it is less common than infiltrating ductal carcinoma (IDC), few data have been reported that address the biologic features of ILC in the context of their clinical outcome. In the present study we undertook an extensive comparison of ILC and IDC using a large database to provide a more complete and reliable assessment of their biologic phenotypes and clinical behaviors.

METHODS

The clinical and biological features of 4140 patients with ILC were compared with those of 45,169 patients with IDC (not otherwise specified). The median follow-up period was 87 months.

RESULTS

In comparison with IDC, ILC was significantly more likely to occur in older patients, to be larger in size, to be estrogen and progesterone receptor positive, to have lower S-phase fraction, to be diploid, and to be HER-2, p53, and epidermal growth factor receptor negative. It was more common for ILC than for IDC to metastasize to the gastrointestinal tract and ovary. The incidence of contralateral breast cancer was higher for ILC patients than for IDC patients (20.9% versus 11.2%; P < 0.0001). Breast preservation was modestly less frequent in ILC patients than in IDC patients. The 5-year disease-free survival was 85.7% for ILC and 83.5% for IDC (P = 0.13). The 5-year overall survival was 85.6% for ILC and 84.1% for IDC (P = 0.64).

CONCLUSION

Despite the fact that the biologic phenotype of ILC is quite favorable, these patients do not have better clinical outcomes than do patients with IDC. At present, management decisions should be based on individual patient and tumor biologic characteristics, and not on lobular histology.

Targeted therapy in breast cancer: the HER-2/neu gene and protein

The HER-2/neu oncogene, a member of the epidermal growth factor receptor or erb gene family, encodes a transmembrane tyrosine kinase receptor that has been linked to prognosis and response to therapy with the anti-HER-2-humanized monoclonal antibody, trastuzumab (Herceptin, Genentech, South San Francisco, CA) in patients with advanced metastatic breast cancer. HER-2/neu status has also been tested for its ability to predict the response of breast cancer to other therapies including hormonal therapies, topoisomerase inhibitors, and anthracyclines. This review includes an analysis of 80 published studies encompassing more than 25,000 patients designed to consider the relative advantages and disadvantages of the various methods of measuring HER-2/neu in clinical breast cancer specimens. Southern blotting, PCR amplification detection, and fluorescence in situ hybridization assays designed to detect HER-2/neu gene amplification are compared with HER-2/neu protein overexpression assays performed by immunohistochemical techniques applied to frozen and paraffin-embedded tissues and enzyme immunoassays performed on tumor cytosols. The significance of HER-2/neu overexpression in ductal carcinoma in situ and the HER-2/neu status in uncommon female breast conditions and male breast cancer are also considered. The role of HER-2/neu testing for the prediction of response to trastuzumab therapy in breast cancer is reviewed along with the current studies designed to test whether HER-2/neu status can predict the response to standard and newer hormonal therapies, cytotoxic chemotherapy, and radiation. The review will also evaluate the status of serum-based testing for circulating HER-2/neu receptor protein and its ability to predict disease outcome and therapy response.

Medullary carcinoma, provocative now as then

The recent observation that studies of BRCA1-associated tumors contain a high proportion of medullary carcinomas and ductal carcinomas with medullary features has re-introduced pathologists to an old diagnostic problem. The term "medullary carcinoma" dates to the 19th century, but the modern entity was introduced in 1949 by Moore and Foote, who described a carcinoma with a lymphoid infiltrate, a favorable prognosis, and low frequency of metastasis. Almost three decades later, Ridolfi et al proposed specific criteria for diagnosis, resulting in an entity with an even more favorable prognosis and a lower incidence. The reproducibility and clinical relevance of the diagnosis have been questioned recently, and new criteria have been proposed and compared. The tumors typically express cytokeratin 7, often vimentin and S100-protein, but not cytokeratin 20. The usual ones are positive for p53 and negative for estrogen receptor, Her2/neu, and bcl-2. Medullary carcinomas express e-cadherin and beta-catenin more often than ordinary high-grade ductal carcinomas, and the former have genetic differences from the latter. The lymphoid infiltrate of medullary carcinomas is related to beta-actin fragments exposed by apoptotic cells. The present review discusses historical and recent developments and emphasizes diagnostic criteria.

Differential amplification and overexpression of HER-2/neu, p53, MIB1, and estrogen receptor/progesterone receptor among medullary carcinoma, atypical medullary carcinoma, and high-grade invasive ductal carcinoma of breast

CONTEXT

Medullary carcinoma (MC) is a special type of breast cancer that has a better prognosis than atypical medullary carcinoma (AMC) and high-grade invasive ductal carcinoma (HGIDC) with prominent lymphocytic infiltrates. What accounts for the different clinical courses of these carcinomas, despite their similar histology, is unknown. To address this issue, we performed a comparative study of amplification and overexpression of HER-2/neu and expression of several other important biochemical markers (p53, MIB1, and estrogen receptor [ER]/progesterone receptor [PR]) in these 3 cancer groups.

OBJECTIVE

To evaluate HER-2/neu, p53, MIB1, and ER/PR as markers in the differential diagnosis of MC, AMC, and HGIDC.Design.-Nine cases of MC, 13 cases of AMC, and 16 cases of HGIDC with prominent lymphocytic infiltrates were identified according to strict histologic criteria. All tests were performed on formalin-fixed, paraffin-embedded archival tissues. HER-2/neu gene amplification was examined by fluorescence in situ hybridization using PathVysion HER-2 DNA probes. Expression of HER-2/neu, p53, MIB1, and ER/PR was detected by immunohistochemistry. chi2 and Student t tests were applied for statistical analyses.

RESULTS

None of 9 cases of MC examined had either amplification or overexpression of HER-2/neu (0%). In contrast, HER-2/neu amplification was observed in AMC (46%, P <.025) and HGIDC (56%, P <.005). All 3 categories of tumors had similar percentages of expression of p53 (78% of MC, 77% of AMC, and 69% of HGIDC) and MIB1 (89% of MC, 92% of AMC, and 94% of HGIDC). Immunostaining for ER/PR was rarely positive in either MC or AMC, and there were no significant differences of expression of ER/PR between these 2 lesions (P >.05). However, the expression rate of ER/PR (31%/44%) in HGIDC is higher than in both MC (P =.05) and AMC (P =.01).

CONCLUSIONS

Medullary carcinoma of breast is distinct from AMC and HGIDC with prominent lymphocytic infiltrates in amplification and overexpression of HER-2/neu. This difference may account for its different clinical and biological behavior, and may potentially aid in diagnosis and management of these groups of patients.

The clinical evaluation of HER-2 status: which test to use?

Accurate determination of the status of the type I receptor tyrosine kinase HER-2 in breast carcinomas provides significant insight into patient prognosis and may also inform selection of chemotherapeutic and hormonal treatments. At present, however, the single most important application of HER-2 testing is in the selection of patients for treatment with targeted therapies such as Herceptin. Although, based on current literature, fluorescence in situ hybridization (FISH) detection of HER-2 gene amplification may provide more accurate information in this context, this method is not yet widely available. Therefore, screening by immunohistochemistry (IHC) for HER-2 protein, backed by rigorous quality controls and FISH testing of equivocal cases with intermediate staining intensity, remains the current practice. In laboratories with highly standardized testing and quality assurance procedures, this protocol appears highly effective. Improvements in fixation procedures, standardization of antibodies, and use of automated image analysis may all increase the precision of IHC testing. However, on the basis of current data, there is a case to be made for the wider implementation of FISH testing to determine HER-2 status in breast cancer.

The Her-2/neu gene and protein in breast cancer 2003: biomarker and target of therapy

The HER-2/neu oncogene encodes a transmembrane tyrosine kinase receptor with extensive homology to the epidermal growth factor receptor. In this review, the association of HER-2/neu gene and protein abnormalities with prognosis and response to therapy with trastuzumab and to other therapies in breast cancer is presented. By considering a series of 80 published studies encompassing more than 25,000 patients, the relative advantages and disadvantages of Southern blotting, polymerase chain reaction amplification, and fluorescence in situ hybridization assays designed to detect HER-2/neu gene amplification are compared with HER-2/neu protein overexpression assays performed by immunohistochemical techniques applied to frozen and paraffin-embedded tissues and enzyme immunoassays performed on tumor cytosols. The significance of HER-2/neu overexpression in ductal carcinoma in situ and the HER-2/neu status in uncommon female breast conditions and male breast cancer are also considered. The role of HER-2/neu testing for the prediction of response to trastuzumab therapy in breast cancer is presented as well as its potential impact on responses to standard and newer hormonal therapies, cytotoxic chemotherapy, and radiation. The review also evaluates the status of serum-based testing for circulating HER-2/neu receptor protein and its ability to predict disease outcome and therapy response.

Prognostic and predictive value of HER2/neu oncogene in breast cancer

Assessment of HER2/neu oncogene has been used as both a prognostic and predictive marker for breast cancer. However, the choice of the best method to assess the status of HER2/neu oncogene in breast cancer tissue remains controversial. A variety of techniques are available to detect HER2/neu gene amplification and overexpression. Tissue-based detection methods by immunohistochemistry (IHC) and/or fluorescence in situ hybridization (FISH) offers a clear advantage over other approaches. FISH is a costly and relatively difficult assay and yet appears to be a better predictor of response to Herceptin (Trastuzumab) therapy and patient outcome. IHC is less expensive and is easier to perform; however, it suffers from a high rate of false negativity and positivity as well as inter-observer variability among pathologists. Suggestions have been made to use IHC as a screening procedure followed by confirmation by FISH in selected cases. Considering the importance of an accurate assessment of HER2/neu oncogene in selecting therapy, a better alternative may be to use FISH as the primary testing for HER2/neu oncogene. Herceptin therapy is associated with several side effects and is expensive. Thus, in the long term, it may be more cost-effective to use the FISH procedure and reduce the possibility of under-treatment or over-treatment of breast cancer patients. In addition, assessment of HER2/neu oncogene on every newly diagnosed early breast carcinoma may not be necessary. Metastatic lesions, when they occur, can be sampled by fine needle aspiration biopsy or core needle biopsy for assessment of HER2/Neu status.

Occult axillary lymph node metastases in breast cancer do matter: results of 10-year survival analysis

Axillary lymph node status is one of the most powerful prognostic factors for patients with breast cancer and is often critical in stratifying patients into adjuvant treatment regimens. In 203 apparently node-negative cases of breast cancer, a combination of immunohistochemical staining and step-sectioning identified occult metastases in 25% of cases. Ten-year follow-up information is available for these patients. Histologic features of the primary tumor and immunohistochemical staining for estrogen receptor, progesterone receptor, Her-2, and p53 were also evaluated. With multivariate analysis, both occult metastases and higher histologic grade of the primary tumor were independent predictors of disease-free survival. Histologic grade was the only significant independent predictor of overall survival. Estrogen receptor, progesterone receptor, Her-2, and p53 status did not predict the presence of metastases or survival when all tumor types were considered together. Metastases >0.5 mm significantly predicted a poorer disease-free survival when invasive ductal carcinomas were considered alone. Histologic grade was significantly associated with disease-free survival in the premenopausal and perimenopausal patients but not in the postmenopausal patients. The presence of occult metastases approached significance for overall survival in the premenopausal and perimenopausal patients but not in the postmenopausal patients.

HER2/neu amplification in breast cancer: stratification by tumor type and grade

The presence of HER2/neu gene amplification is prognostically and therapeutically significant for patients with breast cancer. We sought to determine whether a relationship exists between HER2/neu gene amplification and the histologic type and grade of tumor. The histologic features and corresponding HER2/neu amplification results of 401 cases of invasive breast carcinoma were reviewed. Lobular carcinomas were less likely than ductal carcinomas to have HER2/neu amplification. Amplification was less frequent in Scarff-Bloom-Richardson grade I ductal carcinomas than in grades 2 and 3. Metastatic carcinomas frequently displayed HER2/neu amplification (6/20 [30%]). Our results support a correlation between HER2/neu amplification and the histologic type and grade of breast cancer. We suggest reexamination of tumors diagnosed as Scarff-Bloom-Richardson grade I invasive ductal carcinomas or lobular carcinomas if the lesion displays HER2/neu amplification to assure the exclusion of a higher grade of lesion or of missed ductal components.

Comparison of HER-2/neu oncogene amplification detected by fluorescence in situ hybridization in lobular and ductal breast cancer

BACKGROUND

Abnormal expression of the HER-2/neu oncogene, a tyrosine kinase-type transmembrane growth factor receptor localized to chromosome 17q, has been associated with poor prognosis and the prediction of therapy response in invasive breast cancer. The comparative incidence and significance of HER-2/neu gene amplification for lobular and ductal breast cancer have not been previously characterized.

DESIGN

Formalin-fixed, paraffin-embedded primary breast cancer tissue sections from 71 women diagnosed with invasive lobular carcinoma were tested for HER-2/neu gene amplification by fluorescence in situ hybridization (FISH) method using the Ventana unique sequence probe (Ventana Medical Systems, Tucson, AZ). A series of 106 cases of invasive ductal carcinoma was similarly processed and tested. Lymph node status was available for 155 (88%) of the 177 cases and 82 (46%) were lymph node-negative (LN-) and 73 (41%) were lymph node-positive (LN+). Patients were treated for a mean of 65 months (range 1-169 months).

RESULTS

9 of 71 (13%) cases of lobular cancer featured HER-2/neu gene amplification, whereas 51 (48%) of 106 cases of ductal cancer showed amplification (P < 0.0001). On univariate analysis of combined lobular and ductal cases, HER-2/neu gene amplification detected by FISH predicted disease-related death (P < 0.0001). HER-2/neu gene amplification also predicted disease-related death in lobular cases alone (P = 0.003), LN+ lobular cases separately (P = 0.019), and LN- and LN+ ductal cases separately and alone (P < 0.0001). Multivariate analysis of the lobular group alone revealed that LN+ status (P = 0.015) and stage (P = 0.01) were independent predictors of disease-related death, and HER-2/neu gene amplification reached near significance (P = 0.086). In the ductal carcinoma group alone, HER-2/neu gene amplification (P = 0.03), lymph node status (P = 0.0001), tumor stage (P = 0.0001), and tumor grade (P = 0.044) were independent predictors of overall disease survival.

CONCLUSIONS

HER-2/neu gene amplification detected by FISH was identified at a significantly lower rate in lobular compared with ductal breast cancer. HER-2/neu gene amplification when present in lobular breast cancer is a significant adverse prognostic factor.

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.