HER2 status and efficacy of adjuvant anthracyclines in early breast cancer: a pooled analysis of randomized trials

Evaluation of the prognostic and predictive value of HER family mRNA expression in high-risk early breast cancer: a Hellenic Cooperative Oncology Group (HeCOG) study

The aim of the study was to evaluate the prognostic ability of the transcriptional profiling of the HER family genes in early breast cancer, as well as to investigate the predictive value of HER2 mRNA expression for adjuvant treatment with paclitaxel. RNA was extracted from 268 formalin-fixed paraffin-embedded (FFPE) tumour tissue samples of high-risk breast cancer patients enrolled in the randomised HE10/97 trial, evaluating the effect of dose-dense anthracycline-based sequential adjuvant chemotherapy with or without paclitaxel. The mRNA expression of all four HER family members was assessed by kinetic reverse transcription-polymerase chain reaction (kRT–PCR). The overall concordance between kRT–PCR and IHC/FISH for HER2 status determination was 74%. At a median follow-up of 8 years, multivariate analysis showed that EGFR and HER2 mRNA expression was associated with reduced overall survival (OS). HER3 and HER4 mRNA level had a favourable prognostic value in terms of OS and disease-free survival (DFS), respectively. Adjusting for HER2 mRNA expression, OS and DFS did not differ between treatment groups. These data indicate that EGFR as well as HER2 are prognostic factors of worse clinical outcomes, whereas HER3 and HER4 gene transcription is associated with better prognosis in high-risk early breast cancer. However, HER2 mRNA expression did not predict clinical benefit from paclitaxel. Kinetic RT–PCR represents an alternative method for evaluating the expression of HER family members in FFPE breast carcinomas.

A personalized approach to cancer treatment: how biomarkers can help

BACKGROUND

The present approach to cancer treatment is often referred to as "trial and error" or "one size fits all." This practice is inefficient and frequently results in inappropriate therapy and treatment-related toxicity. In contrast, personalized treatment has the potential to increase efficacy and decrease toxicity.

CONTENT

We reviewed the literature relevant to prognostic, predictive, and toxicity-related markers in cancer, with particular attention to systematic reviews, prospective randomized trials, and guidelines issued by expert panels. To achieve personalized treatment for cancer, we need markers for determining prognosis, predicting response to therapy, and predicting severe toxicity related to treatment. Among the best-validated prognostic markers currently available are serum concentrations of alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), and lactate dehydrogenase (LDH) for patients with nonseminoma germ cell tumors and tissue concentrations of both urokinase plasminogen activator and plasminogen activator inhibitor 1 (PAI-1) for breast cancer patients. Clinically useful therapy predictive markers are estrogen and progesterone receptors to select patients with breast cancer for treatment with endocrine therapy and human epidermal growth factor receptor 2 (HER-2) to select breast cancer patients for treatment with trastuzumab (Herceptin). Markers available for identifying drug-induced adverse reactions include thiopurine methyltransferase (TPMT) to predict toxicity from thiopurines in the treatment of acute lymphoblastic leukemia and uridine diphosphate glucuronyltransferase to predict toxicity from irinotecan in the treatment of colorectal cancer.

CONCLUSIONS

Validated prognostic, predictive, and toxicity markers should help cancer treatment move from the current trial-and-error approach to more personalized treatment.

The epidermal growth factor receptor family in breast cancer

THE HUMAN EPIDERMAL GROWTH FACTOR RECEPTOR (HER) FAMILY COMPRISES FOUR HOMOLOGOUS MEMBERS: EGFR, HER-2, HER-3, and HER-4. The activation of these receptors triggers a complex series of signal transduction pathways which affect pivotal tumorigenic processes. The deregulation of HER signaling is seen in several human malignancies. HER-2 is now recognized as a key oncogene in breast cancer pathogenesis. Assessment of HER-2 status is of central importance in the prognosis of breast cancer patients. In the light of clinical data suggesting that HER-2 can also be useful as a predictive marker both for trastuzumab and chemotherapy, standardized determination of the HER-2 status in tumors has become more important. Moreover, current data provide evidence for the significance of HER-3 and HER-4 alterations in breast carcinogenesis. Because of the complex interactions among the HER receptors, it is likely that the effect on cell proliferation and tumor growth depends on receptor trans-signaling and thus, the evaluation of the combined expression pattern of all family members is of particular interest. This review presents the current evidence highlighting the role of the family as a whole panel and an update on the role of HER-3 and HER-4 receptors in breast cancer. Moreover, we provide updated data regarding the prognostic value of HER family members giving emphasis to novel methods for the determination of their status, such as real-time polymerase chain reaction. In addition, we review recent therapeutic approaches aimed at targeting the HER family in breast cancer patients.

Practice of HER-2 immunohistochemistry in breast carcinoma in Austria

Practice and accuracy of immunohistochemistry is known to vary highly. Reliability of HER-2 immunohistochemistry is critical because of its role in patient selection for therapeutical options in breast cancer. Therefore reliability of HER-2 immunohistochemistry in pathology laboratories in Austria was assessed. Ten tissue specimens of invasive ductal breast carcinomas and three cell line samples were tested. Presence/absence of gene amplification was determined by FISH to be used as a gold standard. Laboratories were asked to stain and assess slides using their routine immunohistochemical staining protocol. Overall the study consisted of 311 tests on tissue specimens and 142 on cell lines. In all cases manual scoring was performed. Participation was voluntary and was 94%. Overall sensitivity was 90.5% and specificity 99.2%. Overscoring including true false positive results were found in 6.7% and 6.3% in tissue specimens and cell lines, respectively. False negative determinations were obtained in 1.9% and 2.8% of tissue specimens and cell lines, respectively. HercepTest showed slightly higher reliability in comparison with individualized staining methods. By manual scoring inaccurate scoring affected 12.3% of test results and 62% of the laboratories. In conclusion participation rate and accuracy of HER-immunohistochemistry was high all over the country. Manually performed scoring demonstrated some limitations.

Node-positive Breast Cancer: Which Are the Best Chemotherapy Regimens?

Breast cancer-associated mortality has been significantly reduced since the 1990s, mainly because of early diagnosis and systemic therapeutic interventions. All three therapy components - cytostatic therapy, endocrine therapy and targeted antibody therapy - are at present necessary tools for the curative treatment of primary breast cancer. This article reviews the evidence base for the use of various chemotherapy schedules in patients with primary, node-positive breast cancer, including schedules in combination with targeted HER2/neu therapy.

EGFR/HER2 in breast cancer: a biological approach for molecular diagnosis and therapy

Novel cancer therapies have focused on specific molecular markers present in malignant tumors. The rationale of targeted therapy relies on the knowledge of molecular mechanisms involved in carcinogenesis and their influence in clinical outcome allied to a more specific and less toxic treatment. Activation of EGF receptor and HER2 is an important factor for initiation and progression of malignancies, including breast cancer where the status of HER2 is an essential step in the diagnostic workup; EGFR overexpression has been associated to the so-called basal-like breast carcinomas, which opens a new avenue for diagnosis and therapeutic approach in these tumors. This review will focus on mechanisms of HER2 and EGF receptor upregulation, the targeted therapies that are currently in use for these receptors, possible combined therapies, as well as the approach for molecular diagnosis from the pathologist's point of view.

Gene expression of topoisomerase II alpha (TOP2A) by microarray analysis is highly prognostic in estrogen receptor (ER) positive breast cancer

INTRODUCTION

Overexpression of Topoisomerase II alpha (TOP2A) has been implicated with gene amplification of the 17q21 amplicon and consecutively with ErbB2 overexpression and amplification. However, gene amplification does not necessarily correlate with RNA and protein expression. There is growing evidence that TOP2A protein expression is a strong prognostic and TOP2A gene amplification might be a predictive marker (particularly for the use of anthracyclines).

METHODS

Large scale analysis was performed using Affymetrix microarray data from n = 1,681 breast cancer patients to evaluate TOP2A expression.

RESULTS

TOP2A expression showed a strong correlation with tumor size (chi(2)-test, P < 0.001), grading (P < 0.001), ErbB2 (P < 0.001) and Ki67 expression (P < 0.001) as well as nodal status (P = 0.042). Survival analysis revealed a significant prognostic value in ER positive (n = 994; log rank P < 0.001), but not in ER negative breast cancer patients (n = 369, P = 0.35). The prognostic impact of TOP2A expression was independent of Ki67 expression in ER positive tumors (P = 0.002 and P = 0.007 for high and low Ki67, respectively). Moreover a worse prognosis of high TOP2A expressing tumors was found in the subgroup of ErbB2 negative tumors (P < 0.001) and a trend among ErbB2 positive tumors (P = 0.11). The prognostic value of TOP2A was independent of whether the patients were untreated or had received adjuvant therapy. In multivariate Cox regression analysis including standard parameters TOP2A emerged to be the top prognostic marker (HR 2.40, 95% CI 1.68-3.43, P < 0.001).

CONCLUSION

TOP2A expression is an independent prognostic factor in ER positive breast cancer and could be helpful for risk assessment in ER positive breast cancer patients.

HER-2 and topoisomerase II as predictors of response to chemotherapy

HER2 overexpression or amplification has been shown to be associated with a poor prognostic effect in women with breast cancer. At least eight analyses based on randomized trials have examined the relationship between HER2 and the differential effect of anthracycline compared with non-anthracycline-containing regimens. Only three of these studies were sufficiently powered to show a significant interaction between HER2 and anthracycline- versus non-anthracycline-containing treatments, but because all of the study results tended to be in the same direction, it is not surprising that three recent meta-analyses of published data have suggested that anthracycline-containing regimens provide more benefit than non-anthracycline-containing regimens in women whose tumors are overexpressed or amplified (positive) for HER2. Since topoisomerase II is a known target of the anthracyclines, it has been postulated that this relationship is actually based on the proximity of HER2 to the topoisomerase II alpha gene (TOP2A) in the 17q chromosome. At least four recent studies have suggested that deletion and amplification of the TOP2A gene are associated with poor prognosis and are predictive of greater response to anthracycline-containing than to non-anthracycline-containing regimens. However, in at least one of those studies, HER2 positivity was as or more predictive. Although it has been suggested that HER2 positivity is predictive of better response to higher-dose anthracycline-containing regimens compared with standard anthracycline-containing regimens and to taxane- compared with non-taxane-containing regimens, these relationships have not been robust or consistent. Additional studies will be required to clarify these relationships.