Type 1 protein tyrosine kinases in Chinese breast carcinomas: a clinicopathologic study

Quantitative multiplexed analysis of ErbB family coexpression for primary breast cancer prognosis in a large retrospective cohort

BACKGROUND

Assessment of outcome using a single prognostic or predictive marker is the current basis of targeted therapy, but is inherently limited by its simplicity. Multiplexing has provided better classification, but has only been done quantitatively using RNA or DNA. Automated quantitative analysis is a new technology that allows quantitative in situ assessment of protein expression. The authors hypothesized that multiplexed quantitative measurement of ErbB receptor family proteins may allow better prediction of outcome.

METHODS

The authors quantitatively assessed the expression of 6 proteins in 4 subcellular compartments in 676 patients using breast carcinoma tissue microarrays. Then using Cox proportional hazards modeling and unsupervised hierarchical clustering, they assessed the prognostic value of the expression singly and multiplexed.

RESULTS

Epidermal growth factor receptor (EGFR), HER-2, and HER-3 expression were associated with decreased survival. Multivariate analysis showed high HER-2 and HER-3 expression maintained independence as prognostic markers. Hierarchical clustering of expression data defined a small class enriched for HER-2 expression with 40% 10-year survival, compared with 55% using conventional methods. Clustering also revealed a similarly poor-prognostic subgroup coexpressing EGFR and HER-3 (but low for estrogen receptor, progesterone receptor, and HER-2) with a 42% 10-year survival.

CONCLUSIONS

This work shows that the combined analysis of protein expression improved prognostic classification, and that multiplexed models were superior to any single-marker-based method for prediction of 10-year survival. These methods illustrate a protein-based, multiplexed approach that could more accurately identify patients for targeted therapies.

Over-expression of c-erbB-2 correlates with nuclear morphometry and prognosis in breast carcinoma in Asian women

AIM

We aimed to investigate the immunohistochemical expression of c-erbB-2 in invasive breast carcinoma in Asian women and its correlations with clinicopathological parameters and nuclear morphometry. Patients were followed up for disease relapse and overall survival, and the data were reviewed in conjunction with c-erbB-2 over-expression.

METHODS

Paraffin sections from 321 invasive breast cancers were immunohistochemically stained with anti-human c-erbB-2 antibody using the streptavidin-biotin technique.

RESULTS

c-erbB-2 was over-expressed in 110 (34.3%) cases, with an inverse correlation with oestrogen receptor (ER) and progesterone receptor (PR) status (p=0.0001) and a positive correlation with histological grade (p=0.017). Nuclear morphometry in 96 cases revealed rounder nuclei in c-erbB-2 negative tumours (p=0.0322) when compared with c-erbB-2 positive tumours. Among c-erbB-2 positive cases, malignant cells of histological grade 3 tumours revealed larger nuclear area and perimeter than grade 1 and 2 cases (p=0.0095, p=0.03, respectively) while increasing tumour size correlated with greater nuclear perimeter (p=0.046). c-erbB-2 positivity was significantly associated with poor survival when all patients were included in the analysis (p=0.0166) and for subsets of node positive, histological grade 1 and 2, and ER positive tumours, and in women aged over 50 years (p=0.0047, p=0.0367, p=0.0092, p=0.0096, respectively).

CONCLUSIONS

c-erbB-2 was independently prognostic when histological grade, nodal and ER status were considered. Our results show that c-erbB-2 over-expression correlates with poor histological grade and negative ER/PR status, and predicts poor overall survival in Asian women with breast cancer.

Metaplastic breast carcinomas exhibit EGFR, but not HER2, gene amplification and overexpression: immunohistochemical and chromogenic in situ hybridization analysis

INTRODUCTION

Metaplastic breast carcinomas constitute a heterogeneous group of neoplasms, accounting for less than 1% of all invasive mammary carcinomas. Approximately 70-80% of metaplastic breast carcinomas overexpress the epidermal growth factor receptor (EGFR). Human epidermal growth factor receptor (HER)2 and EGFR have attracted much attention in the medical literature over the past few years owing to the fact that humanized monoclonal antibodies against HER2 and therapies directed against the extracellular ligand-binding domain or the intracellular tyrosine kinase domain of EGFR have proven successful in treating certain types of human cancer. We investigated whether HER2 and EGFR overexpression was present and evaluated gene amplification in a series of metaplastic breast carcinomas.

METHOD

Twenty-five metaplastic breast carcinomas were immunohistochemically analyzed using a monoclonal antibody (31G7) for EGFR and two antibodies for HER2 (Herceptest and CB11) and scored using the Herceptest scoring system. Gene amplification was evaluated by chromogenic in situ hybridization using Zymed Spot-Light EGFR and HER2 amplification probe. The results were evaluated by bright field microscopy under 40x and 63x objective lenses.

RESULTS

Nineteen (76%) metaplastic breast carcinomas exhibited EGFR ovexpression, and among these EGFR amplification (defined either by large gene clusters or >5 signals/nucleus in >50% of neoplastic cells) was detected in seven cases (37%): three carcinomas with squamous differentiation and four spindle cell carcinomas. One case exhibited HER2 overexpression of grade 2+ (>10% of cells with weak to moderate complete membrane staining), but HER2 gene amplification was not detected.

CONCLUSION

Metaplastic breast carcinomas frequently overexpressed EGFR, which was associated with EGFR gene amplification in one-third of cases. Our findings suggest that some patients with metaplastic breast carcinomas might benefit from novel therapies targeting EGFR. Because most metaplastic breast carcinomas overexpress EGFR without gene amplification, further studies to evaluate EGFR activating mutations are warranted.

Expression of HER3, HER4 and their ligand heregulin-4 is associated with better survival in bladder cancer patients

The epidermal growth factor system has been associated to prognosis in patients with bladder cancer based mainly on the expression of the epidermal growth factor (EGF) receptor 1 (EGFR) and HER2 and their activating ligands. Since limited information exists concerning the expression of other parts of the EGF system, we examined the expression of the receptors HER3 and HER4 and their activating ligands, the heregulins (HRGs), in bladder cancer patients. Biopsies from bladder cancer tumours were obtained from 88 patients followed for a median of 23 months (range, 1-97 months). The mRNA content of four ligands and their isoforms (HRG1alpha, HRG1beta, HRG2alpha, HRG2beta, HRG3 and HRG4) and two receptors (HER3 and HER4) was quantified by real-time PCR. A significantly lower mRNA expression level of HER3 (P=0.0003), HRG2alpha (P=0.0159), HRG2beta (P=0.0007) and HRG4 (P<0.0001) was observed in muscle-invasive (T2-T4) tumours as compared to superficial (Ta) tumours. The expression of HER3 mRNA correlated strongly to overall survival (P=0.0042); increased expression of HER4 (P=0.0261) and HRG4 (P=0.0245) was also associated with better prognosis. Interestingly, patients with coexpression of HER3 (P=0.0034) or HER4 (P=0.0080) together with their stimulating ligand HRG4 showed even better survival than for HER3 or HER4 alone. Our results together with previous data suggest a dual face for the EGF system. While it is well established that an increased signalling through HER1 and HER2 is related to a poor prognosis, our data suggest that signalling through HER3 and HER4 is related to a favourable outcome in bladder cancer patients.

Coexpression of the type 1 growth factor receptor family members HER-1, HER-2, and HER-3 has a synergistic negative prognostic effect on breast carcinoma survival

BACKGROUND

The clinical significance of coexpression of type 1 growth factor receptor (T1GFR) family members remains largely unknown. The objective of the current study was to determine the frequency and the possible prognostic effect of coexpression of HER-1, HER-2, HER-3, and HER-4 by breast carcinoma.

METHODS

Tissue microarrays were constructed using clinically annotated formalin-fixed, paraffin-embedded tumor samples from 242 patients with invasive breast carcinomas with a median 15-year follow-up. The levels of TIGFR family members (HER-1-HER-4) were measured by immunohistochemistry. K-means clustering algorithm, as well as univariate (Kaplan-Meier, log-rank test) and multivariate (Cox regression) survival analyses were applied to the data set.

RESULTS

Using univariate analysis, expression of HER-1, HER-2, and HER-3, but not HER-4, was significantly associated with decreased patient disease-specific survival (P < 0.05). Kaplan-Meier survival analysis showed that coexpression of >/= 2 of HER-1, HER-2, and HER-3 in any combination was associated with reduced patient disease-specific survival compared with single marker expression or no expression (35% vs. 65% vs. 78% 10-year survival rates, P = 0.001). Using multivariate analysis, expression of >/= 2 of HER-1, HER-2, and HER-3 was independent of lymph node status and tumor size.

CONCLUSIONS

In a cohort of patients with breast carcinoma, the authors observed T1GFR family member coexpression (HER-1, HER-2, and HER-3) to have a negative synergistic effect on patient outcome, independent of tumor size or lymph node status. Thus, coexpression of T1GFR family members identified a subset of patients with a poor disease prognosis who may potentially benefit from therapy simultaneously targeting several T1GFR family members.

Pregnancy and breast cancer: a population-based study

The incidence of pregnancy-associated breast cancer, i.e. during pregnancy and lactation, and of pregnancy subsequent to a breast-cancer diagnosis will increase as more women choose childbearing at a later age. Few larger series are published on pregnancy-associated breast cancer. In a population-based study, we evaluated the outcome and prognostic factors in 173 breast-cancer patients. One hundred and twenty-two patients had pregnancy-associated breast cancer (20 coincident with pregnancy and 102 during lactation) and 51 patients had pregnancy subsequent to breast cancer. The median follow-up time was 151 months. Histopathological parameters and immunoreactivity for oestrogen and progesterone receptors c-erbB-2 and c-erbB-4 were studied. All three groups had tumours with high histological grade, low frequency of hormone receptors and high expression of c-erbB-2. The pregnancy and lactation groups were near identical with regard to all histopathological parameters and outcome. In the two pregnancy-associated breast-cancer groups, tumours were significantly larger, with more extensive lymph-node involvement. For node-negative tumours the respective 5- and 10-year survival rates were 62% and 50% in the pregnancy group and 60% and 50% in the lactation group. For node-positive tumours, respective 5- and 10-year survival rates were 50% and 34% in the pregnancy group and 50% and 33% in the lactation group. In the subsequent group, overall survival was high in both node-negative and -positive groups, with 5- and 10-year survival rates of 80% and 73% and 86% and 76%, respectively. Tumour size, lymph-node status, histological grade, progesterone receptor, oestrogen receptor and c-erbB-2 were significant prognostic factors in the pregnancy-associated breast-cancer patients.