When is a tumor marker ready for prime time? A case study of c-erbB-2 as a predictive factor in breast cancer

Detection of HER-2/neu-positive circulating epithelial cells in prostate cancer patients

HER-2/neu may play a role in prostate carcinogenesis. The aim of this study was to use the expression of HER-2/neu as a molecular marker for the detection of circulating tumour cells (CTCs) in the blood of patients with prostate cancer (PC). Blood samples were collected from 42 patients with PC and nine healthy volunteers. Immunomagnetic beads were used to harvest epithelial cells from peripheral blood mononuclear cells. Total RNA was extracted and reverse transcribed before analysis by real-time PCR with HER-2/neu-specific primers. CTCs were HER-2/neu positive in six out of 11 (54%) patients with metastatic disease and in three out of 31 (9.6%) patients with localised PC (P=0.004). In blood samples from nine healthy volunteers, we detected no expression of HER-2/neu. The present method appears to be minimally invasive, highly sensitive and a specific approach for detecting CTCs in PC. Furthermore, it may help better target HER-2/neu in advanced PC.

Biological rationale for endocrine therapy in breast cancer

Oestrogens are heavily implicated in the risk to, and progression of, breast cancer. Therapeutic strategies targeted at the oestrogenic stimulus to the breast and hormone-sensitive breast cancers are extremely attractive measures both to prevent the disease and to treat established tumours. The present review outlines the biological rationale for such endocrine therapy and traces the evolution whereby irreversible surgical procedures have been replaced by potent and specific drugs. In particular, the development of the latest generation of agents which inhibit oestrogen biosynthesis (aromatase inhibitors) is considered by defining the central role of the aromatase enzyme, its regulation and contribution to circulating and tumour endogenous oestrogens. The nature of response and resistance which may be elicited following the use of endocrine therapy is also described as this may determine the optimal use of aromatase inhibitors and, more generally, anti-hormone therapy in the management of women at high risk to, or with, breast cancer.

The role of biological markers as predictors of response to preoperative chemotherapy in large primary breast cancer

The aim of this prospective study was to evaluate biological markers, their correlation with response and outcome, and the change in these markers under the influence of preoperative chemotherapy (PCT) in patients with a large primary breast cancer. One hundred and thirty-five women were treated with PCT, followed by locoregional therapy and adjuvant treatment. Estrogen receptor (ER), progesterone receptor (PgR), HER-2, p53, and cathepsin D were determined by immunohistochemistry (IHC) before and after PCT. The overall response (OR) was 70% and the pathologic complete response (pCR) was 13%. Forty-four percent of the patients could be offered breast-conserving surgery (BCS). At a median follow-up of 50 mo the overall survival is 82% and the disease-free survival is 70%. No local recurrence (LR) has developed following BCS. Invasive ductal carcinoma (IDC) was more frequently ER-negative and HER-2-positive than invasive lobular carcinoma (ILC). P53-negative and ER-negative patients seemed to be more chemosensitive compared to p53-positive patients (74% vs 53%) and ER-positive patients (75% vs 65%), but this difference did not reach statistical significance. A trend toward higher complete pathologic remission rate was seen for ER-negative patients (p = 0.0609). PgR, HER-2, and cathepsin D were not related to response. The pattern of biological markers did not change with PCT, making repeated determination useless.

Prognostic markers in breast cancer: the reliability of HER2/neu status in core needle biopsy of 325 patients with primary breast cancer

INTRODUCTION

The assessment of HER2/neu overexpression in tissue provides information about one of the most relevant prognostic and predictive markers in breast cancer: overexpression of HER2/neu is associated with worse prognosis in primary breast cancer. Since core needle biopsy is increasingly used for the diagnosis of breast cancer, the purpose of this study was to assess the reliability of HER2/neu evaluation using this technique in patients with primary breast cancer.

PATIENTS AND METHODS

We investigated the accuracy of immunohistochemical assessment of HER2/neu in core needle biopsies compared with surgically obtained specimens in 325 patients with primary breast cancer. In patients strongly positive for HER2/neu, additional fluorescence in situ hybridization (FISH) analysis of needle biopsies was performed.

RESULTS

Using immunohistochemistry alone, accuracy of HER2/neu assessment in core biopsies in relation to surgically removed specimens was 92% and increased to 96% with additional FISH analysis (weighted Kappa coefficient: 0.86).

DISCUSSION

As proven with this large series of patients, the assessment of HER2/neu status by core needle biopsy in breast cancer is accurate. Notwithstanding, in order to minimize the number of false-positive results, strongly positive core needle biopsies identified using immunohistochemistry should be confirmed by FISH analysis.

Comparative value of tumour grade, hormonal receptors, Ki-67, HER-2 and topoisomerase II alpha status as predictive markers in breast cancer patients treated with neoadjuvant anthracycline-based chemotherapy

The aim of this study was to evaluate the predictive value of five different biological factors in breast cancer patients treated with neoadjuvant anthracycline-based chemotherapy: (1) tumour grade scored according to the Elston-Ellis classification, (2) hormonal receptor (HR) status; (3) tumour cell proliferation evaluated by Ki-67 staining, (4) HER-2 and topoisomerase II alpha (TopoIIalpha) expression evaluated by immunohistochemistry (IHC), (5) HER-2 and TopoIIalpha amplification evaluated by real-time polymerase chain reaction (PCR). 119 patients with operable breast cancer were treated with six cycles of FEC (100 5-fluorouracil (5-FU) 500 mg/m2, Epirubicin 100 mg/m2, Cyclophosphamide 500 mg/m2). Tumour response was assessed clinically and by computed tomography (CT) scan, then by pathological assessment. The clinical overall response (OR) was 80%, with 19% of complete responders (CR). The radiological OR was 71%, with 16% of CR. A pathological CR was demonstrated in 13% of the patients according to the Sataloff classification. In the multivariate analysis, the absence of HR expression and Ki-67 > or = 20% were predictive for a clinical CR. A high tumour grade was predictive for a pathological CR. Overexpression or amplification of HER2 or Topollcalpha were not predictive of response.

Markers of increased risk for failure of adjuvant therapies

Mortality from breast cancer has been declining in the Western World since 1985. Arguably, widespread application of effective adjuvant systemic therapy has been a considerable contributing factor. Data from individual trials and the Oxford Overview Meta-analyses demonstrate that both endocrine and chemotherapy are associated with significant and substantive proportional reductions in annual hazard rates of relapse and death. These statistics raise the question: Should all patients be treated with all therapies in order to ensure an ongoing sharp decline in breast cancer mortality? The answer to this question depends on the perspectives of the patient, her caregiver, and her society towards the relative toxicities and benefits of therapy. If a patient is willing to accept toxicities for any benefit, then the answer is yes. However, if a woman is willing to forego some benefit to avoid the toxicities of therapy, then the clinician should carefully use well-validated prognostic and predictive factors to help the patient select her most acceptable treatment plan.

Vascular endothelial growth factor is associated with the efficacy of endocrine therapy in patients with advanced breast carcinoma

BACKGROUND

Vascular endothelial growth factor (VEGF) is a mediator of angiogenesis and is associated with a poor prognosis in patients with primary breast carcinoma. In the current study, the authors investigated whether there was an association between VEGF levels in tumor tissues and response rates to first-line, systemic therapy in patients with advanced breast carcinoma.

METHODS

In 172 tumors from patients with primary breast carcinoma who developed distant metastases during follow-up, cytosolic levels of VEGF were measured using a quantitative enzyme-linked immunosorbent assay. Patients received either endocrine therapy (n = 96) or chemotherapy (n = 76) as first-line treatment after they were diagnosed with advanced disease.

RESULTS

In univariate logistic regression analysis for response to endocrine therapy in 96 patients, an increasing level of VEGF, as a log-transformed, continuous variable, was correlated with a poor rate of response (P = 0.043). In multivariate analysis, a significantly lower rate of response to first-line endocrine therapy was found for patients who had high VEGF levels compared with patients who had low VEGF levels (P = 0.025). Similar results were found for the subgroup of 82 patients who received tamoxifen (P = 0.011). An association of VEGF with response to first-line endocrine therapy was found in addition to a predictive impact for estrogen receptor/progesterone receptor status (P = 0.027). VEGF levels did not predict the rate of response to first-line chemotherapy.

CONCLUSIONS

The results demonstrated that the level of VEGF affects response to endocrine therapy independent of steroid hormone receptor status and may help to refine further the indication for this treatment in individual patients. Further studies are warranted to explain this underlying resistance to endocrine therapy.

Coexistence of HER2 over-expression and p53 protein accumulation is a strong prognostic molecular marker in breast cancer

INTRODUCTION

Many laboratories are currently evaluating the usefulness of determination of HER2, p53, and Ki67 proliferation indices using immunohistochemical techniques in cancer. Although the available studies suggest that these factors might indeed be helpful in making treatment decisions in cancer patients, their clinical usefulness is still controversial.

METHODS

Expression of HER2, p53, and Ki67 was examined by immunohistochemistry in samples of breast tissue from 506 patients with invasive ductal carcinoma, obtained between 1981 and 1999 (median follow up period 82 months), and their significance for prognosis was analyzed.

RESULTS

Of the 506 carcinoma tissue samples, 20.1%, 29.0%, and 53.6% were positive for HER2 over-expression, p53 protein accumulation, and Ki67 expression, respectively. Over-expression of HER2 significantly reduced disease free (P = 0.02) and overall survival (P = 0.005). Accumulation of p53 protein significantly decreased disease free (P = 0.01) and overall survival (P = 0.01). Patients with tumors that were positive for both HER2 and p53 relapsed and died within a significantly shorter period of time after surgery (P = 0.0001 and P < 0.0001, respectively). In multivariate analysis, patients with both HER2 and p53 positive tumors had considerably decreased overall survival (P = 0.04), as did patients with larger tumor size and positive lymph node status.

CONCLUSION

The findings of the present study indicate that the coexistence of HER2 over-expression and p53 protein accumulation is a strong prognostic molecular marker in breast cancer.

Optimizing the Use of Anthracyclines in the Adjuvant Treatment of Early-Stage Breast Cancer

Anthracyclines have been incorporated into adjuvant chemotherapy regimens for breast cancer since the 1980s. A metaanalysis confirmed that regimens containing anthracyclines result in better disease-free and overall survival than standard CMF (cyclophosphamide/methotrexate/5-fluorouracil), with a proportional reduction of 11% in risk of death at 10 years with the addition of these agents. Dose escalation of doxorubicin results in outcome improvement up to a threshold dose beyond which no further improvement is seen. Epirubicin, with its better toxicity profile, can be escalated to higher doses than doxorubicin, with better outcomes associated with higher dose levels. Tumors expressing HER2/neu may respond better to anthracycline-containing regimens than to standard CMF, but this remains controversial. Newer regimens combining anthracyclines with taxanes may offer a slight additional advantage in terms of disease-free and overall survival in some patient populations. The scheduling of treatment is important, with recent results of dose-dense scheduling showing a greater survival benefit than conventional scheduling. Ongoing clinical trials should further define the best choice of anthracycline and the optimal dose and schedule of treatment.

High-dose chemotherapy with hematopoietic stem-cell rescue for high-risk breast cancer

BACKGROUND

The use of high-dose adjuvant chemotherapy for high-risk primary breast cancer is controversial. We studied its efficacy in patients with 4 to 9 or 10 or more tumor-positive axillary lymph nodes.

METHODS

Patients younger than 56 years of age who had undergone surgery for breast cancer and who had no distant metastases were eligible if they had at least four tumor-positive axillary lymph nodes. Patients in the conventional-dose group received fluorouracil, epirubicin, and cyclophosphamide (FEC) every three weeks for five courses, followed by radiotherapy and tamoxifen. The high-dose treatment was identical, except that high-dose chemotherapy (6 g of cyclophosphamide per square meter of body-surface area, 480 mg of thiotepa per square meter, and 1600 mg of carboplatin per square meter) with autologous peripheral-blood hematopoietic progenitor-cell transplantation replaced the fifth course of FEC.

RESULTS

Of the 885 patients, 442 were assigned to the high-dose group and 443 to the conventional-dose group. After a median follow-up of 57 months, the actuarial 5-year relapse-free survival rates were 59 percent in the conventional-dose group and 65 percent in the high-dose group (hazard ratio for relapse in the high-dose group, 0.83; 95 percent confidence interval, 0.66 to 1.03; P=0.09). In the group with 10 or more positive nodes, the relapse-free survival rates were 51 percent in the conventional-dose group and 61 percent in the high-dose group (P=0.05 by the log-rank test; hazard ratio for relapse, 0.71; 95 percent confidence interval, 0.50 to 1.00).

CONCLUSIONS

High-dose alkylating therapy improves relapse-free survival among patients with stage II or III breast cancer and 10 or more positive axillary lymph nodes. This benefit may be confined to patients with HER-2/neu-negative tumors.

Role of proliferation in HER2 status predicted response to doxorubicin

The role of HER2 in predicting response to doxorubicin (DXR) therapy in breast cancer was evaluated in vivo in a series of breast carcinomas from 220 patients with tumors larger than 2.5 cm and treated with 3 cycles of DXR (75 mg/m(2)) as neoadjuvant chemotherapy. Patients with HER2-positive tumors were more frequently responsive to DXR treatment compared with HER2-negative patients (p = 0.05; Mantel-Haenszel Chi(2) = 0.009). Progesterone receptor (PgR) negativity, but not mutated p53, was also associated with response to DXR (p = 0.05; Mantel-Haenszel Chi(2) = 0.004). Further analysis of those correlations using breast carcinoma cell lines characterized for different biologic parameters revealed a trend between HER2 positivity/PgR negativity and greater DXR sensitivity, but the strongest direct correlation was found between the proliferation rate and sensitivity to DXR (r = 0.82, p = 0.00009). Neither p53 nor the DXR target molecule topoisomerase-II-alpha was significantly associated with in vitro sensitivity to DXR. Thus, whereas data showed that the major biologic parameter associated with in vitro response to DXR in breast cancer cells appears to be the tumor proliferation rate, HER2 expression together with PgR negativity may serve as the counterpart of the proliferation marker in predicting the in vivo response to DXR.

HER-2/neu and topoisomerase IIalpha in breast cancer

In breast cancer, the predominant genetic mechanism for oncogene activation is through an amplification of a gene. The HER-2 (also known as ErbB2/c-erbB2/HER-2/neu) oncogene is the most frequently amplified oncogene in breast cancer, and its overexpression is associated with poor clinical outcome. In addition to its important role in breast cancer growth and progression, HER-2 is also a target for a new form of chemotherapy. Breast cancer patients have been treated with considerable success since 1998 with trastuzumab, a recombinant antibody designed to block signaling through HER-2 receptor. HER-2 has also been implicated in altering the chemosensitivity of breast cancer cells to different forms of conventional cytotoxic chemotherapy, particularly of topoII-inhibitors (e.g., anthracyclines). Topoisomerase IIalpha gene is located just by the HER-2 oncogene at the chromosome 17q12-q21 and is amplified or deleted in almost 90% of the HER-2 amplified primary breast tumors. Recent data suggests that amplification and deletion of topoisomerase IIalpha may account for both relative chemosensitivity and resistance to anthracycline therapy, depending on the specific genetic defect at the topoIIalpha locus. Expanding our understanding of HER-2 amplification also changes its role in the pathogenesis of breast cancer. HER-2 is an oncogene that clearly can drive tumor induction and growth and is also a target for a new kind of chemotherapy, but its function as a marker for chemoselection may be due to associated genetic changes, of which topoisomerase IIalpha is a good example. Moreover, despite potential evidence that genes other than HER-2, such as topoisomerase IIalpha, may be more important predictors of therapeutic response in breast cancer, HER-2 status still has a very significant role in therapeutic selection, mainly as the major criterion for administering trastuzumab in treating breast cancer. Thus, the clinical and therapeutic importance of the HER-2 and topoisomerase IIalpha status to breast cancer management should only increase in the next few years.

Invasion factors uPA/PAI-1 and HER2 status provide independent and complementary information on patient outcome in node-negative breast cancer

PURPOSE

The independent clinical relevance of invasion factors urokinase-type plasminogen activator (uPA)/PAI-1 and HER2 status was evaluated in lymph node-negative breast cancer patients (N = 118) without adjuvant systemic therapy after long-term follow-up of more than 10 years (median, 126 months).

PATIENTS AND METHODS

Levels of uPA and its inhibitor PAI-1 were prospectively measured by enzyme-linked immunosorbent assay in primary tumor tissue extracts. HER2 gene amplification (HER2_AMP) was evaluated by fluorescence in situ hybridization (FISH; Ventana Medical Systems HER-2/neu probe; Tucson, AZ), and HER2 protein overexpression (HER2_EXP) was evaluated by immunohistochemistry (IHC; Oncogene Science antibody Ab-3; Cambridge, MA) on parallel-cut formalin-fixed paraffin-embedded tissue sections.

RESULTS

uPA/PAI-1 was high (either one or both factors were high) in 44% of the tumors. HER2_AMP was detected by FISH in 33% of the patients, and HER2_EXP was found by IHC in 44% of the patients. In a multivariate analysis of established and tumor-biologic prognostic factors, uPA/PAI-1 was the only independent prognostic factor for disease-free survival ([DFS]; P <.001; relative risk [RR], 8.3; 95% confidence interval [CI], 3.4 to 20.4). Although HER2_AMP and HER2_EXP did not reach significance for DFS, they were significant for overall survival (OS), even in multivariate analysis (HER2_AMP: P =.004; RR, 3.7; 95% CI, 1.5 to 9.2; HER2_EXP: P =.009; RR, 3.4; 95% CI, 1.4 to 8.7).

CONCLUSION

After long-term follow-up, uPA/PAI-1 levels in primary tumor tissue reliably and strongly indicate an aggressive course of disease in lymph node-negative breast cancer independent of HER2 status. The particular prognostic effect of HER2 status on OS may reflect its ability to predict resistance to systemic therapy.

Variation of the prognostic significance of HER-2 expression in breast cancer according to tumor size

The prognostic importance of HER-2 status in breast cancer has been investigated extensively, but findings have not been uniform across immunohistochemical studies using fixed, paraffin-embedded specimens. We speculate that studies with an overrepresentation of large tumors might not produce evidence for an independent effect of a single marker because breast tumors of larger size tend to exhibit multiple adverse attributes as the malignancy advances through the metastatic cascade. Further, it has been posited that results from certain studies of biologic markers might be generalizable only to larger tumors because tumor repositories tend to house a disproportionate number of larger tumors. To test our hypothesis that the prognostic effect of HER-2 status might be modified by the size of the tumor, we conducted a survival analysis of a nested case-case sample of 156 women diagnosed with primary breast cancer from 1983 to 1995. Relative risks (RRs) and confidence intervals (CIs) for recurrence in relation to HER-2 status were estimated using a multivariate Cox proportional hazards model. Immunohistochemistry of archival tissue was used to detect HER-2 expression. Positive HER-2 status was associated with recurrence (RR = 4.24, 95% CI 1.30-13.78) among patients with axillary lymph node-positive involvement. This analysis identified an interaction (p < 0.01) between tumor size and overexpression. Stratification by tumor size revealed an increased risk of recurrence associated with HER-2-positive tumors that were <or=2 cm in size (RR = 13.68, 95% CI 1.06-175.76), whereas no such association was observed among patients with HER-2-positive tumors larger than 2 cm. Eligible patients without available tumor tissue tended to have smaller tumors compared to study participants. Our results might partly explain the variation in evidence across HER-2 prognostic studies using fixed tissue and might apply to other putative markers of prognosis in breast cancer.

Locally advanced/inflammatory breast cancers treated with intensive epirubicin-based neoadjuvant chemotherapy: are there molecular markers in the primary tumour that predict for 5-year clinical outcome?

BACKGROUND

Locally advanced and/or inflammatory breast cancer (LABC) is a heterogeneous disease. Molecular markers may help to understand this heterogeneity. This paper reports the results of a study assessing the potential prognostic or predictive value of HER-2, p53, cyclinD1, MIB1, ER and PgR expression by immunohistochemistry from patients included in an EORTC-NCIC-SAKK trial.

PATIENTS AND METHODS

A total of 448 patients with a cytological or histological diagnosis of LABC were randomised into a trial comparing two anthracycline-based neoadjuvant regimens. Chemotherapy was followed by standard locoregional therapy. Survival was comparable in both arms. We collected and analysed centrally paraffin-embedded tumour specimens from 187 (72.5%) of 258 patients that had a histological diagnosis.

RESULTS

Of the patients included in this molecular marker study 114 relapsed and 91 died. In the multivariate analysis p53 positivity was associated with a shorter progression-free survival [hazard ratio (HR) = 1.96; 95% CI 1.33-2.91; P = 0.0008) and a shorter overall survival (HR = 1.98; 95% CI 1.28-3.06; P = 0.002). PgR positivity predicted for a longer overall survival (HR = 0.54; 95% CI 0.35-0.83; P = 0.0045).

CONCLUSIONS

p53 was an independent factor predicting for survival. In order to clarify whether p53 is a pure prognostic and/or a predictive factor, a phase III trial is being conducted (EORTC 10994/BIG 00-01 study) using functional assay in yeast from frozen tumour samples.

Prognostic and predictive indicators in operable breast cancer

Because of its biological heterogeneity and wide spectrum of responsiveness to different treatments, breast cancer is a complex disease of difficult clinical management. Over the past several years, knowledge of the molecular mechanisms regulating normal and aberrant cell growth leading to cancer has been enhanced. These advances have enabled the identification of an increasing number of surrogate biomarkers, which have been correlated with prognosis or used as predictors of response to specific treatments. Axillary nodal status, age, tumor size, pathologic grade, and hormone receptor status are the established prognostic and/or predictive factors for selection of adjuvant treatments. The role of new biomarkers, such as p53, HER2/neu, angiogenesis, and the proliferation index value, is promising; however, the clinical value of their determination must be provided by prospective clinical studies.

Her-2/neu overexpression and response to oophorectomy plus tamoxifen adjuvant therapy in estrogen receptor-positive premenopausal women with operable breast cancer

PURPOSE

Studies evaluating the relationship of HER-2/neu breast tumor status and response to adjuvant endocrine therapy have reached conflicting conclusions about resistance of HER-2/neu-positive tumors to this treatment. We studied 282 patients participating in a randomized controlled trial of adjuvant oophorectomy and tamoxifen or observation who had estrogen receptor-positive tumors and whose tumors were evaluated for HER-2/neu overexpression by immunohistochemistry.

PATIENTS AND METHODS

Univariate and multivariate Cox proportional hazards regression models and Kaplan-Meier disease-free and overall survival estimate methods were used.

RESULTS

HER-2/neu overexpression was a negative prognostic factor for overall survival. In univariate analyses, in HER-2/neu-positive patients, the hazard ratio (HR) for disease-free survival (DFS) with adjuvant endocrine therapy was 0.37 (95% confidence interval [CI], 0.26 to 0.89); for HER-2/neu-negative patients, the corresponding HR for DFS was 0.48 (95% CI, 0.31 to 0.71). The overall survival (OS) data were HR=0.26 (95% CI, 0.07 to 0.92) and HR=0.68 (95% CI, 0.32 to 1.42) for HER-2/neu-positive and HER-2/neu-negative patients, respectively. In multivariate models, the P values for tests of interaction of HER-2/neu status and response to adjuvant endocrine therapy were 0.18 and 0.07 for DFS and OS, respectively. Kaplan-Meier DFS and OS curves and 3-year DFS estimates were consistent in showing greater benefit to the HER-2/neu-positive subgroup given adjuvant treatment.

CONCLUSION

HER-2/neu overexpression does not adversely and may favorably influence response to adjuvant oophorectomy and tamoxifen treatment in patients with estrogen receptor-positive tumors.

Evaluation of the epidermal growth factor receptor (EGFR) in colorectal tumours and lymph node metastases

Overexpression of the epidermal growth factor receptor (EGFR) often correlates with an aggressive tumour phenotype and poor prognosis. To examine the relevance of EGFR in colorectal cancer, we determined the expression of EGFR protein in 249 colorectal adenocarcinomas and 42 lymph node metastases using immunohistochemistry. Moreover, we investigated a (CA)(n) dinucleotide repeat polymorphism of the EGFR gene in a subset of 114 tumours. High levels of EGFR protein were observed in 123/249 (49.4%) samples. EGFR expression in colorectal carcinomas correlated with differentiation grade (P=0.014). However, there were no associations with Dukes' stage, site, patient age or gender. EGFR protein expression did not influence survival in this colorectal cancer patient cohort (P>or=0.05). Expression was not identical in paired colorectal tumours and lymph node metastases, with only 17/42 (40.5%) samples showing equivalent EGFR levels (P>0.05). The distribution of the (CA)(n) dinucleotide repeat alleles in colorectal adenocarcinomas was not associated with EGFR protein expression (P>0.05). These results indicate that while EGFR overexpression is a common event in colorectal carcinogenesis, it does not influence patient prognosis.

Adjuvant therapy for breast cancer: recommendations for management based on consensus review and recent clinical trials

Determining the optimal individual adjuvant systemic therapy for breast cancer patients is a challenging undertaking because it requires translating data from clinical trials that have involved thousands of patients into a highly individualized, risk-adjusted approach for the patient at hand. Choosing adjuvant therapy for women with breast cancer includes consideration of four issues: A) evaluation of risk of relapse; B) extrapolation of results from clinical trials; C) therapeutic ratio, and D) the patient's preferences following a thorough discussion with her physician. Data from recently completed phase III adjuvant trials and worldwide consensus conferences document the benefits of adjuvant therapy in improving disease-free survival and overall survival for patients diagnosed with invasive breast cancer >1.0 cm in size. The benefits of hormonal therapy are clear, but limited to patients with estrogen receptor-positive breast cancer. Anthracyclines lead to improved outcomes compared with nonanthracycline regimens. Taxanes appear to improve disease-free survival in patients with node-positive disease, although longer follow-up is required to assess their impact on overall survival. Some countries have reported a reduction in the mortality rate from breast cancer over the past several years. The improved survival rate is due, at least in part, to the use of adjuvant systemic therapy. Ongoing studies are evaluating targeted therapies, with the potential of remarkably improving patient outcome.

Amplification and expression of genes from the 17q11 approximately q12 amplicon in breast cancer cells

Amplification of a portion of 17q11 approximately q12 involving the human epidermal growth factor receptor-2 (HER-2/neu) gene is common in solid tumors. HER-2/neu amplification in breast cancer is associated with a poor prognosis and may predict response to therapeutic interventions. The molecular complexity and informative content of the 17q11 approximately q12 amplified DNA remain largely unknown. Study of available sequence information in public database allowed us to construct a contig in bacterial artificial chromosome that covers this region. We have identified a several hundred kilobase core segment from this region that is amplified in three out of three breast cancer cell lines with HER-2/neu amplification. There is striking correlation between amplification and overexpression of genes from this region. Amplified and overexpressed genes, in addition to HER-2/neu, may play functional roles in the pathogenesis of breast cancer and may serve as additional targets for therapy. Published by Elsevier Science Inc.

Quality control for biomarker determination in oncology: the experience of the Italian Network for Quality Assessment of Tumor Biomarkers (INQAT)

Biomarker analysis and evaluation in oncology is the product of a number of processes (including managerial, technical and interpretation steps) which need to be monitored and controlled to prevent and correct errors and guarantee a satisfactory level of quality. Several biomarkers have recently moved to clinical validation studies and successively to clinical practice without any definition of standard procedures and/or quality control (QC) schemes necessary to guarantee the reproducibility of the laboratory information. In Italy several national scientific societies and single researchers have activated -- often on a pilot level -- specific external quality assessment protocols, thereby potentially jeopardizing the clinical reality even further. In view of the seriousness of the problem, in 1998 the Italian Ministry of Health sponsored a National Survey Project to coordinate and standardize the procedures and to develop QC programs for the analysis of cancer biomarkers of potential clinical relevance. Twelve QC programs focused on biomarkers and concerning morphological, immunohistochemical, biochemical, molecular, and immunoenzymatic assays were coordinated and implemented. Specifically, external QC programs for the analytical phase of immunohistochemical p53, Bcl-2, c-erb-2/neu/HER2, and microvessel density determination, of morphological evaluation of tumor differentiation grade, and of molecular p53 analysis were activated for the first time within the project. Several hundreds of Italian laboratories took part in these QC programs, the results of which are available on the web site of the Network (www.cqlaboncologico.it). Financial support from the Italian Government and the National Research Council (CNR) will guarantee the pursuit of activities that will be extended to new biomarkers, to preanalytical phases of the assays, and to revision of the criteria of clinical usefulness for evaluating the cost/benefit ratio.

Doctor's dilemma: incorporating tumor markers into clinical decision-making

Physicians are often faced with the dilemma of how to incorporate tumor markers into routine clinical decision-making. Tumor markers may influence clinical decisions at various stages of cancer therapy: screening, diagnosis, prognosis, detection of early relapse, and monitoring of therapy. We use the examples of beta-human chorionic gonadotrophin (beta-HCG) and alpha-fetoprotein (AFP) as markers for germ cell tumors (GCT), and prostate-specific antigen (PSA) as a marker for prostate cancer, to illustrate their use and limitations for these purposes. We then focus on monitoring and choice of treatment by presenting three vignettes; these highlight the potential benefits and problems associated with the use of tumor markers for monitoring and detection of early relapse in asymptomatic patients.

c-erbB-2 in breast cancer: development of a clinically useful marker

c-erbB-2 amplification and/or overexpression occurs in 20% to 30% of breast cancers and appear to be associated with a more aggressive phenotype. Detecting abnormalities in c-erbB-2 might provide important clinical information for breast cancer patients. However, several of the potential clinical uses of c-erbB-2 remain unproven. Many variables influence c-erbB-2 results, including selection and characteristics of test populations and methods of analysis. Current literature suggests two roles for c-erbB-2, either as a pure prognostic factor with no association with therapy or as a factor predictive of benefit from specific types of systemic treatments. c-erbB-2 appears to be only a weak prognostic factor, although some individual studies suggest greater prognostic importance. c-erbB-2 abnormalities appear to predict for relative, but not absolute, resistance to endocrine therapy in estrogen receptor (ER)-positive women. When adjuvant chemotherapy is indicated, some studies have indicated that patients with c-erbB-2-positive cancers (by immunohistochemistry [IHC] or fluoresence in situ hybridization [FISH]) receive more benefit from anthracycline-containing regimens as compared to alkylating agents. c-erbB-2 testing appears critical for selecting patients with metastatic disease who should receive the anti-c-erbB-2 antibody, trastuzumab. Prospective randomized clinical trials of trastuzumab as adjuvant therapy are underway. Well-designed, prospective, randomized clinical trials (designed to test the value of c-erbB-2) or formal meta-analyses will help to better establish the predictive role of c-erbB-2 in breast cancer.

Mammographically detected breast cancers and the risk of axillary lymph node involvement: is it just the tumor size?

PURPOSE

In early breast cancer the knowledge of the risk of axillary node involvement is important in determining local as well as systemic therapy. Because of the increased acceptance of mammography, there has been an increase in the diagnosis of small, mammographically detected tumors. The objective of this study is to determine whether mammographically detected breast cancers have a lower risk of axillary node involvement compared to those detected clinically.

PATIENTS AND METHODS

From our patient database of stage I and II breast cancer we identified 980 patients with tumors < or = 2 cm whom had axillary node dissection. Four hundred thirty-five (44%) patients presented with abnormal mammograms without clinically palpable tumors; 545 (56%) patients had clinically detected tumors. The median size of the mammographically detected tumors is 1.0 cm, and the median size of the clinically detected tumors is 1.5 cm. The median age of the patients with mammographically detected tumors is 61 (range: 29-87) compared to 53 (range: 27-88) in those with palpable tumors.

RESULTS

Fourteen percent of the patients with mammographically detected tumors had positive axillary nodes compared to 26% of those with clinically detected tumors. Eight percent of patients with mammographically detected tumors had a single positive, while the clinically detected tumors 11% had a single positive node. Thirteen percent of patients with < or = 1 cm tumors and 25% with tumors 1.1 cm to 2 cm had positive axillary nodes. Because the smaller size of the mammographically detected tumors could explain the lower proportion of positive axillary nodes, we analyzed separately the < or = 1 cm tumors. In the group of < or = 1 cm tumors, 9% had positive axillary nodes iftheywere mammographically detected compared to 19% if clinically detected. Four percent had a single positive node while 5% had multiple positive nodes. If the tumors were palpable and < or = 1 cm 9% had a single positive node and 10% had multiple positive nodes. Mammo-graphicallydetected tumors < or = 1 cm had similargrade to clinically detected tumors. In multivariate analysis, method of detection remains a significant variable impacting on the risk of axillary node involvement even in tumors < or = 1 cm.

DISCUSSION

The risk of axillary node involvement is lower in mammographically detected tumors compared to clinically detected tumors independent of tumor size or grade. Mammography detects tumors early in their metastatic progression. The majority of the axillary node-positive patients who are mammographically detected have a single positive axillary node. Method of detection may need to be considered when assessing the risk of axillary node involvement and incorporated in the staging.

Prognostic and predictive value of thymidine phosphorylase activity in early-stage breast cancer patients

The antitumor effects of 5-fluorouracil (5-FU) and its derivatives depend upon the activity of nucleoside metabolic enzymes in tumor tissues. Thymidine phosphorylase (TP) converts 5'-deoxy-5-fluorouridine (5'-DFUR), an intermediate metabolite of capecitabine, to 5-FU. The relationship between TP expression in tumor tissues and patient survival was retrospectively examined in early-stage breast cancer patients treated with either oral 5'-DFUR administered for 6 months or surgery alone in a prospective randomized controlled trial. Thymidine phosphorylase expression in tumor cells and tumor-associated stromal (TAS) cells was examined by immunohistochemistry in 650 tissue samples from patients in this trial (n = 1217). Eight-year follow-up data showed that high TP expression in tumor cells was a significant prognostic indicator of a favorable outcome only for the patients in the 5'-DFUR group. Thus, TP expression was shown to be a predictive factor of 5'-DFUR efficacy. Conversely, a low TP expression in TAS cells was also a potent favorable prognostic indicator. These results on TP status in 2 tumor cell types could provide novel information for predicting prognosis for a patient subgroup, which would receive a probable therapeutic effect from 5'-DFUR, and presumably, from adjuvant therapy of capecitabine in early-stage breast cancer. Determination of TP status might also identify a patient subgroup whose prognosis is quite favorable even without adjuvant therapy. Further investigations on prognostic and predictive implications of TP activity in a clinical setting are warranted.

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.

HER2 testing in patients with breast cancer: poor correlation between weak positivity by immunohistochemistry and gene amplification by fluorescence in situ hybridization

OBJECTIVE

To evaluate amplification of the HER-2/neu gene by fluorescence ir situ hybridization (FISH) in tumors with weakly positive (2+) immunohistochemical staining.

METHODS

A total of 1556 breast tumor biopsy specimens were referred to Mayo Medical Laboratories, Rochester, Minn, for HER2 testing between August and December 2000. Immunohistochemical (IHC) analysis was performed with use of a diagnostic test for the assessment of HER2 overexpression, the HercepTest. The IHC-stained slides were interpreted and scored on a scale ranging from 0 to 3+ according to Food and Drug Administration-approved guidelines. All specimens scored as 2+ were also routinely evaluated by FISH with use of a HER-2/neu DNA probe kit (PathVysion). Specimens were determined to be amplified if the ratio of HER-2/neu signals to chromosome 17 centromere (CEP17) signals was higher than 2.0.

RESULTS

Thirty-eight percent of the specimens evaluated with the HercepTest were scored 0, 35% were 1+, 14% were 2+, and 13% were 3+. Of the 216 tumor specimens scored as 2+, 26 (12%) had a high level of HER-2/neu gene amplification, 54 (25%) demonstrated duplication of HER2, 4 (2%) deleted HER-2/neu and/or CEP17, and 123 (57%) had no apparent HER-2/neu anomaly, no apparent CEP17 anomaly, nor apparent single gain (aneusomy) of CEP17.

CONCLUSION

We recommend that all specimens with a 2+ HercepTest result be evaluated by FISH for HER-2/neu gene amplification. The results of both assays should be considered before making a decision to recommend anti-HER2 therapy.

The Role of c-erbB-2 as a predictive factor in breast cancer

Most women diagnosed with primary invasive breast cancer are potential candidates to receive adjuvant systemic treatment. Tumor markers that predict the likelihood of response to therapy might help select optimal treatment for individual patients. Of these, c-erbB-2 is the most promising marker. In the past 15 years, over 200 reports related to c-erbB-2 and breast cancer have been published. However, its clinical role remains unclear. c-erbB-2 might serve as either a pure prognostic factor, with no association with therapy, or as a predictive factor of benefit from specific types of systemic treatments. A recent overview suggested that c-erbB-2 is only a weak prognostic factor. A review of the literature suggests that c-erbB-2 overexpression might predict for relative, but not absolute, resistance to endocrine therapy in estrogen receptor-positive women. When adjuvant chemotherapy is indicated, c-erbB-2 positive patients may receive more benefit from anthracycline-containing regimens than alkylating agents. However, if anthracyclines are contraindicated, women with c-erbB-2 positive tumor do derive benefit from alkylating agents. Importantly, c-erbB-2 status appears critical for selecting patients who should receive trastuzumab. Well-designed prospective randomized clinical trials or formal meta-analysis will help to establish the predictive role of c-erbB-2.

The role of adjuvant monoclonal antibody therapy for breast cancer: rationale and new studies

HER2 is a member of the epidermal growth factor receptor (EGFR) family of tyrosine kinases and is involved in the growth, invasion, metastasis, and prognosis of breast cancer. The rationale for prospective trials evaluating the role of anti-HER2 monoclonal antibody therapy for patients with high-risk HER2-positive resected breast cancer is based on several factors. These include 1) the relative and absolute poor prognosis of patients with node-positive, HER2-positive breast cancer; 2) the emerging data of potential importance concerning anthracyclines as a component of adjuvant therapy for patients with HER2-positive breast cancer; 3) the role of taxanes in the management of patients with HER2-positive metastatic breast cancer; and 4) the feasibility and efficacy of molecularly targeted anti-HER2 monoclonal antibody treatment alone or in combination with chemotherapy for patients with advanced breast cancer.

Systemic therapy

A large body of data on systemic therapy has been presented and published in the past year, including new information on primary risk reduction, patient selection for adjuvant systemic therapy, and anthracycline-analogs. New data on ongoing adjuvant trials (including taxane studies), unpublished updates from the fourth Oxford Overview in September 2000, and provocative data on ovarian ablation were important features of the November 2000 National Institutes of Health Consensus Development Conference on Adjuvant Therapy for Breast Cancer. Important new data on anti-estrogen therapy, including aromatase inhibitors and pure antiestrogens, further expand the role of the oldest targeted breast cancer therapy. Trastuzumab and other novel compounds are being investigated as single-agents and in combination with conventional systemic approaches. Discussions on the long-term effects of adjuvant therapy have taken center stage also. These and other important ongoing developments since 2000 are examined in this review article.

Prognostic factors in breast cancer: current and new predictors of metastasis

Decisions regarding the use of adjuvant therapy for breast cancer are strongly influenced by the risk of disease recurrence and death. These risks are now determined by examining the currently recognized breast cancer prognostic factors, including clinical stage, axillary nodal status, tumor size and grade, hormone receptor status, and presence of lymphovascular involvement. Newer factors are being evaluated in an attempt to more precisely define disease-related prognosis. This paper provides an overview of issues that need to be considered when analyzing studies of prognostic factors as well as a review of the currently recognized and the newer candidate prognostic factors.

Update on HER-2 as a target for cancer therapy: herceptin in the clinical setting

Herceptin is the first therapy for breast cancer which targets an oncogene product. This humanized antibody to HER-2 has been shown to have activity as a single agent in a phase II trial of heavily pre-treated patients with advanced breast cancer and, in phase III studies, its use with chemotherapy is associated with higher response rates, longer time to progression and improved survival when compared with chemotherapy alone. Retrospective analysis of data from these pivotal trials suggests that attributable benefit of herceptin is greater in those patients who express HER-2 at the highest levels, that is 3+ expression by immunohistochemistry. Further analysis also implies that cases which are positive for HER-2 by fluorescent in situ hybridization may also benefit from treatment regardless of whether they express HER-2 at the 2+ or 3+ level. Use of herceptin as first-line therapy for metastatic disease in early studies suggest that response rates and clinical benefit rate similar to chemotherapy may be achievable and that survival using this sequential approach may not be compromized. Other combinations of herceptin and chemotherapy have been investigated with phase II data suggesting considerable activity with weekly taxol and when combined with navelbine. The non-linear pharmacokinetics of herceptin suggest that, as doses increased, half-life increases and may be feasible on a 3-weekly schedule. The role of herceptin in the adjuvant setting in the management of breast cancer will be tested in randomized studies of patients who express HER-2 at the highest levels; two of these studies have already begun.