Neu Status Research Articles

HER‐2/neu expression as a predictor of response to neoadjuvant docetaxel in patients with operable breast carcinoma

The use of biologic markers to predict response to neoadjuvant chemotherapy may permit tailoring regimens to achieve maximal tumor response. Taxanes have demonstrated excellent activity in breast carcinoma; however, tumor-specific factors that predict clinical response have not been characterized thoroughly. The authors performed a historic review evaluating the association of tumor prognostic factors and response to neoadjuvant cyclophosphamide and doxorubicin (AC) with or without docetaxel (D) (AC vs. AC+D) in 121 women who previously were enrolled in a Phase III, randomized, clinical trial. Using pretreatment biopsy materials, immunohistochemical studies were performed for estrogen receptor (ER), progesterone receptor (PR), HER-2/neu, p53, and Ki-67. Outcome variables were pathologic complete response (pCR) and positive clinical response (cPOS), which was defined as a >/= 50% regression in clinical tumor size prior to surgery. In a multivariate analysis that controlled for tumor size and lymph node status, improved cPOS rates were observed with the addition of docetaxel in women with HER-2/neu-negative tumors (81% vs. 51%; P < 0.05), yielding an adjusted odds ratio of 3.5 (95% confidence interval, 1.2-13.0) in favor of docetaxel. Women who had HER-2/neu-negative tumors appeared to have a lower response rate with AC alone compared with women who had HER-2/neu-positive tumors (51% vs. 75%; P = 0.06), but response rates were matched when docetaxel was added (81% vs. 78%; P = 0.99). ER, PR, p53, and Ki-67 results were not associated significantly with response rates. HER-2/neu status may predict improved clinical response rates from the addition of docetaxel to anthracycline-based neoadjuvant chemotherapy. Docetaxel may "rescue" the response in women who have HER-2/neu-negative tumors to match that observed in women who have HER-2/neu-positive tumors treated with AC alone.

Real‐time reverse transcription‐PCR and fluorescence in‐situ hybridization are complementary to understand the mechanisms involved in HER‐2/neu overexpression in human breast carcinomas

To evaluate the HER-2/neu status at the mRNA and DNA level of breast carcinomas and to compare it with HER-2/neu receptor overexpression by immunohistochemistry (IHC). In 32 invasive breast carcinomas, frozen tissue was available for real-time detection of HER-2/neu mRNA levels by reverse transcription-polymerase chain reaction (RT-PCR). Corresponding paraffin sections were examined by IHC and fluorescence in-situ hybridization (FISH). Thereby, different IHC and FISH procedures were compared. Using microwave epitope retrieval, all 32 cases scored 3+ on IHC, whereas only 28 out of 32 cases scored IHC 3+ using water bath epitope retrieval. All of these 28 cases showed increased levels of HER-2/neu mRNA. Dual-colour FISH analysis showed corresponding gene amplification in all 28 cases, with two cases showing a peculiar amplification pattern. In the remaining four cases, scoring IHC 2+ using water bath epitope retrieval, mRNA levels were not elevated. Three cases did not have gene amplification and one case showed low-level HER-2/neu gene amplification. All four carcinomas showed chromosome 17 polysomy. Real-time RT-PCR is accurate in selecting breast carcinoma cases scoring 3+ by IHC with high-level gene amplification. Results obtained by dual-colour FISH suggest that mechanisms leading to HER-2/neu receptor overexpression may be different between carcinomas scoring 2+ and 3+ on IHC, with polysomy 17 found in the former and gene amplification in the latter.

Detection of HER-2/neu Gene Amplification Using Chromogenic In Situ Hybridization and Tissue Microarray: Correlation with HER-2/neu Protein Expression Using Immunohistochemistry

Determination of HER-2/neu status in patients with breast carcinoma is important in selecting the patients who may benefit from treatment with the gene-based cancer drug trastuzumab (Herceptin). The HER-2/neu-overexpressing tumors often lack hormone receptors and therefore are not qualified for tamoxifen therapy. Most laboratories perform immunohistochemistry as the first step for assessment of the HER-2/neu protein expression. Because of inconsistency in tissue fixation and processing and interobservor variability, a definite determination of HER-2/neu status may be problematic in some cases. Fluorescence In Situ hybridization currently is recommended as the second step in further evaluation of borderline cases. In this study, we analyzed the status of HER-2/neu gene using a tissue microarray construct and a chromogenic In Situ hybridization method as an alternative to fluorescence. We find that chromogenic in sitcl hybridization is a reliable method for assessment of HER-2/neu gene status with good correlation with HER-2/neu protein expression using immunohistochemistry. (The J Histotechnol 28: 11, 2005)Submitted: August 3 1,2004; Accepted: November 24,2004

Comparison of HER‐2/neu, ER and PCNA expression in premenopausal and postmenopausal patients with breast carcinoma

We attempted to compare the pattern of HER-2/neu, ER and PCNA in premenopausal and postmenopausal patients with breast carcinoma to identify potential biological differences. Five hundred and forty-eight samples from 318 premenopausal and 230 postmenopausal women with invasive ductal carcinoma of the breast were evaluated for HER-2/neu, ER and PCNA expression by immunohistochemistry. HER-2/neu expression showed 27.4% positivity in premenopausal and 24.8% in postmenopausal women; there was no significant difference between the two groups (p>0.05). In contrast, HER-2/neu expression was found to be significantly associated with ER negativity in the two groups (p<0.05 in premenopausal, p<0.001 in postmenopausal patients). However, it was significantly associated with PCNA expression only in the postmenopausal group (p<0.001). 54.4% showed premenopausal tumor cell ER positivity, whereas 64.3% of the postmenopausal group showed positivity. ER expression showed a significant correlation with patient menopausal status (p<0.05). The prevalence of PCNA positivity in the tumor cell components is slightly higher in postmenopausal compared to premenopausal women (p>0.20). The current study is consistent with reports from other groups regarding the correlation of HER-2/neu with adverse pathologic features and with expression of other markers in carcinoma. We also observed there was no trend toward increased HER-2/neu expression in either premenopausal or postmenopausal patients, i.e. there was similar HER-2/neu expression in the two groups. This suggests that HER-2/neu status could be used to determine assignment to specific intensive adjuvant therapy and evaluation of biological behavior in both pre- and postmenopausal patients with breast carcinoma.

B7-H4 Is Highly Expressed in Ductal and Lobular Breast Cancer

This study was designed to investigate the expression of B7-H4 protein, a member of the B7 family that is involved in the regulation of antigen-specific immune responses, in normal breast and in primary and metastatic breast carcinomas. Archival formalin-fixed tissue blocks from breast cancers and normal somatic tissues were evaluated for B7-H4 expression by immunohistochemistry with manual and automated image analysis. The proportion of B7-H4-positive cells and the intensity of B7-H4 staining were compared with histologic type, grade, stage, hormone receptor status, and HER-2/neu status. B7-H4 was detected in 165 of 173 (95.4%) primary breast cancers and in 240 of 246 (97.6%) metastatic breast cancers. B7-H4 staining intensity was greater in invasive ductal carcinomas [24.61 relative units (RU)] and in invasive lobular carcinomas (15.23 RU) than in normal breast epithelium (4.30 RU, P = 0.0003). Increased staining intensity was associated with negative progesterone receptor status (P = 0.014) and history of neoadjuvant chemotherapy (P = 0.004), and the proportion of B7-H4-positive cells was associated with negative progesterone receptor (P = 0.001) and negative HER-2/neu (P = 0.024) status. However, there was no statistically significant relationship between the proportion of B7-H4-positive cells or staining intensity and grade, stage, or other clinicopathologic variables. Low levels of B7-H4 expression were also detected in epithelial cells of the female genital tract, lung, pancreas, and kidney, but B7-H4 was generally absent in most other normal somatic tissues. The nearly ubiquitous expression of B7-H4 in breast cancer, independent of tumor grade or stage, suggests a critical role for this protein in breast cancer biology.

P42 The age-related ER+PR+ expression differs by HER-2/neu status

P42 The age-related ER+PR+ expression differs by HER-2/neu status

Interobserver reproducibility of immunohistochemical HER-2/neu assessment in human breast cancer: An update from INQAT round III.

The clinical interest in HER-2/neu is related to trastuzumab, a drug used to treat patients with invasive breast carcinoma verexpressing the HER-2/neu protein. It is very important to correctly identify those patients who may benefit from trastuzumab by accurate ssessment of the HER-2/neu status. Of the various methods vailable, the Dako Herceptest for immunohistochemical assay is considered the most reliable to reach this goal. The aim of this study was to investigate within a group of Italian laboratories the reproducibility of the results of HER-2/neu assessment by means of the Dako scoring system on slides stained with the Herceptest kit. This study was also conceived as the continuation of one of our previous studies, which was similar in its aims but different in the classification criteria adopted. Our results show that, whereas the intra-observer reproducibility was generally satisfactory, the interobserver reproducibility was not. Moreover, our findings confirm that the two extreme classes (0 and 3+) are more easy to identify than the other two and that the Herceptest does not allow to discriminate optimally between scoring classes 2+ and 3+. These findings are relevant in clinical practice where the treatment choice is based on categories defined by this assay, suggesting the need of adopting educational programs and/or new reference materials to improve the assay performance. (Int J Biol Markers 2005; 20: 189-94).

Non‐invasive (intracapsular) carcinoma ex pleomorphic adenoma: recognition of focal carcinoma by HER‐2/neu and MIB1 immunohistochemistry

Non-invasive carcinoma ex pleomorphic adenoma is defined as a carcinoma arising within the boundaries of a pleomorphic adenoma (PA), but which fails to display invasion beyond the capsule of host PA. Alternative names are intracapsular, in situ, or focal carcinoma. The true nature of non-invasive carcinoma ex-PA is still controversial; for example, it is not clear whether it represents early but genuine carcinomatous changes with the genetic make-up of malignant cells, or simply cytological, possibly metaplastic or 'bizarre' changes in PA. Strong overexpression and amplification of HER-2/neu protein has recently been demonstrated in invasive carcinoma ex-PA. In addition, data from breast cancer studies suggest that amplification of HER-2/neu and overexpression of its gene product is mainly involved in the initiation of breast oncogenesis. We sought to establish whether this method could help to demonstrate that what is described as non-invasive carcinoma ex-PA is really a genuine malignancy, albeit in an early phase. Eleven cases of non-invasive carcinoma (in situ) ex-PA were studied for HER-2/neu status using immunohistochemistry and fluorescent in-situ hybridization (FISH). Cells of focal non-invasive carcinoma ex-PA were strongly positive for HER-2/neu protein, while the cells of the maternal PA were always negative. Two cases of low-grade non-invasive myoepithelial carcinoma ex-PA were negative. In four cases out of a total of six tumours studied by FISH, we detected amplification of HER-2/neu gene signals in tumour cells of focal, non-invasive, carcinoma. The current data suggest that non-invasive carcinoma ex PA is a genuine carcinoma within a PA. However, the presence of cyto-nuclear atypia is not sufficient to make a definite diagnosis of malignant change, which requires a combination of morphology and immunohistochemistry.

P29 Age does affect the HER-2/neu status of breast cancers

P29 Age does affect the HER-2/neu status of breast cancers

HER‐2/neu and p53 overexpression as biomarkers of breast carcinoma in women age 30 years and younger

Although p53 and HER-2/neu overexpression are found in 30% of breast carcinomas in women of all ages and are associated with high rates of lymph node metastases, their role in women age < 30 years has not been studied extensively. The institutional breast cancer data base was searched to identify young women (23-30 years) with breast carcinoma. An immunohistochemical analysis was performed to determine estrogen receptor and progesterone receptor expression and p53 and HER-2/neu overexpression. Positive staining for p53 was defined as nuclear staining in > 10% of tumor cells. HER-2/neu membranous staining was graded as 0, 1 (incomplete, faint staining in > 10% of cells), 2 (weak-to-moderate, complete staining in > 10% of cells), or 3 (complete, strong staining in > 10% of cells). Fluorescence in situ hybridization (FISH) was performed on all samples with > or = 2 and > or = 3 results, and only FISH-positive samples were classified as positive. The overexpression was correlated with clinicopathologic features. Among 44 patients, 1 patient had medullary carcinoma, and 1 had mixed ductal/lobular carcinoma. All remaining patients were diagnosed with invasive ductal carcinoma. The clinical stage was T1 in 5 patients, T2 in 24 patients, T3 in 10 patients, T4 in 4 patients, and unavailable in 1 patient. Positive p53 status was determined in 22 of 44 patients (50%), and positive HER-2/neu status was determined in 18 of 41 patients (44%). Tumors with lymph node metastasis had a significantly greater incidence of HER-2/neu overexpression (P=0.04). Frequent overexpression of HER-2/neu and p53 was found in the patient population. HER-2/neu overexpression was associated significantly with lymph node involvement and, thus, may be a marker for aggressive clinical behavior in patients with breast carcinoma age < or = 30 years.

Detection ofHer-2/neu oncogene in breast carcinoma by chromogenic in situ hybridization in cytologic specimens

Determination of Her-2/neu oncogene amplification is important in the current treatment of breast carcinoma. In addition to fluorescence in situ hybridization (FISH) and immunohistochemical stain (HercepTest), chromogenic in situ hybridization (CISH) has been shown to be a sensitive and specific method to determine the Her-2/neu status of surgical specimens. The effectiveness of CISH in detecting the Her-2/neu oncogene in cytologic specimens has not been well documented. Twenty-five cases of fine needle aspirate smears and touch imprints from infiltrating ductal carcinomas were examined. Both CISH and FISH were performed on each case using a digoxigenin-labeled Her-2 DNA probe for CISH (Zymed) and both Her-2 and chromosome 17 probes for FISH (Vysis). Sixty tumor cells were evaluated in each case. The scoring system and interpretation of CISH were as follows: (1) no amplification (<5 brown dots/nucleus), (2) amplification (>10 brown dots/nucleus), and (3) low-level amplification (5-9 brown dots/nucleus). Of the 25 cases analyzed, 23 (3 amplified and 20 nonamplified) showed similar results for both methods. Two cases were discordant. In these cases, low-level amplification was suggested by CISH but nonamplification by FISH. One of the cases can be explained by polysomy for chromosome 17 by FISH. In conclusion, our preliminary data suggest that CISH is a useful technique to determine Her-2/neu oncogene status in cytologic specimens. In a case of low-level amplification, a CISH chromosome 17 probe should be used, or FISH is recommended for confirmation.

Progesterone receptor by immunohistochemistry and clinical outcome in breast cancer: a validation study

Progesterone receptor is a surrogate marker of estrogen receptor activity in breast cancer and its utility in helping predict clinical outcome has been established using biochemical assays. However, most laboratories worldwide have switched to immunohistochemistry to assess progesterone receptor, but unfortunately no validated immunohistochemical assay exists for progesterone receptor. The purpose of this study was to develop and validate an immunohistochemical assay for progesterone receptor in breast cancer. The assay was based on monoclonal antibody 1294 (DakoCytomation) and slides were scored microscopically using the ‘Allred score’ on a scale of 0–8. The assay was compared to ligand-binding assay in 1235 breast cancers, and a subset (n=362) that received only hormonal therapy was used to define a cutoff for progesterone receptor-positive. Clinical utility was validated in an independent set of samples (n=423) from a clinical trial randomizing premenopausal breast cancer patients to tamoxifen+oophorectomy vs observation following surgery. A cutoff of >2 (corresponding to >1% positive cells) dichotomized patients with significantly better or worse clinical outcome (P=0.0014). Progesterone receptor by immunohistochemistry provided significantly better results than progesterone receptor by ligand-binding assay in predicting clinical outcome. In the clinical trial, a positive result in univariate analyses was associated with significantly improved disease-free and overall survival both in untreated (hazard ratios/P=0.656/0.060 and 0.479/0.005, respectively) and hormonally treated patients (hazard ratios/P=0.529/0.017 and 0.451/0.007, respectively). Positive progesterone receptor remained significant for improved disease-free and overall survival (hazard ratios/P=0.666/0.038 and 0.549/0.007, respectively) in multivariate analyses including the standard variables of tumor size, nodal status, treatment, histological grade, and HER-2/neu status. Estrogen and progesterone receptors are codependent variables and progesterone receptor was a weaker predictor of response to endocrine therapy than estrogen receptor when both were included in multivariate analysis. This is the first comprehensive study assessing the clinical usefulness of progesterone receptor by immunohistochemistry in archival tissue in breast cancer. Progesterone receptor assessed by immunohistochemistry provides useful information about clinical outcome and it is better than progesterone receptor measured by ligand-binding assay.

Chromogenic in situ hybridization analysis of HER‐2/neu status in cytological samples of breast carcinoma

The current use of humanized monoclonal antibody trastuzumab for the treatment of patients with metastatic breast cancer has made evaluation of HER-2/neu status an important clinical issue. Chromogenic in situ hybridization (CISH), in which the DNA probe is detected with an immunohistochemistry (IHC)-like peroxidase reaction, has been recently developed for the assessment of HER-2/neu status in formalin-fixed breast cancer specimens. We have applied the technique of dual-colour CISH using HER-2/neu and chromosome 17 centromere probes in 27 cytological smears, and these cytological samples were obtained from scrapings of fresh breast tumours. We also investigated HER-2/neu amplification and protein overexpression in the corresponding surgical tissues by CISH and IHC using the monoclonal antibody CB11. Of the 27 cytological cases, HER-2/neu gene amplification was observed in nine cases that were positive cases (2+ and 3+) for IHC. Among the 13 IHC positive cases (2+ and 3+), four of them showed no gene amplification. Identical results for the CISH technique were obtained in the matched surgical samples. The scrape samples from fresh breast tumour offer a monolayer cell population that is especially suitable for CISH. This study has shown that the cytological smear might be a good alternative for the CISH test.

Insertional Polymorphisms of Endogenous HERV-K113 and HERV-K115 Retroviruses in Breast Cancer Patients and Age-Matched Controls

Endogenous retroviral sequences resulting from ancient retrovirus infections of germline cells account for up to 8% of the human genome. Most of these sequences are highly truncated, have been altered by mutations, and do not encode functional genes. However, some members of the human endogenous retrovirus (HERV)- K family are remarkably intact and display high genetic homology to mouse mammary tumor virus (MMTV), a retrovirus causing breast cancer in mice. Two full-length HERVs (K113 and K115) have been reported to show insertional polymorphism. We used PCR to investigate the presence of these two HERVs in 102 female breast cancer patients and an equal number of age-matched controls with no history of malignancy (age range: 25–92 years). The two groups showed no significant difference in frequency (HERV-K113, 16.7% vs. 12.7%; HERV-K115, 4.9% vs. 9.8%) and no apparent association with histology, age at diagnosis, receptor status, HER-2/neu status, or TNM stage at diagnosis. This suggests that the two HERV-Ks do not play a pathogenetic role in the majority of breast cancer patients, though they may be involved in a minority of patients. The results are discussed.

Insertional Polymorphisms of Endogenous HERV-K113 and HERV-K115 Retroviruses in Breast Cancer Patients and Age-Matched Controls

Endogenous retroviral sequences resulting from ancient retrovirus infections of germline cells account for up to 8% of the human genome. Most of these sequences are highly truncated, have been altered by mutations, and do not encode functional genes. However, some members of the human endogenous retrovirus (HERV)-K family are remarkably intact and display high genetic homology to mouse mammary tumor virus (MMTV), a retrovirus causing breast cancer in mice. Two full-length HERVs (K113 and K115) have been reported to show insertional polymorphism. We used PCR to investigate the presence of these two HERVs in 102 female breast cancer patients and an equal number of age-matched controls with no history of malignancy (age range: 25-92 years). The two groups showed no significant difference in frequency (HERV-K113, 16.7% vs. 12.7%; HERV-K115, 4.9% vs. 9.8%) and no apparent association with histology, age at diagnosis, receptor status, HER-2/neu status, or TNM stage at diagnosis. This suggests that the two HERV-Ks do not play a pathogenetic role in the majority of breast cancer patients, though they may be involved in a minority of patients. The results are discussed.

HER-2 sérique, cancer du sein et trastuzumab (Herceptine ®)

The HER-2/neu oncogene and its p185 receptor protein are indicators of a more aggressive form of breast cancer. The HER-2/neu status of the tumour guides trastuzumab (Herceptin ®) therapy, a monoclonal antibody directed against the extracellular domain (ECD) of the HER-2/neu oncoprotein. The HER-2/neu ECD is shed from cancer cells into the circulation and is measurable by immunoassay (HER-2/neu Manual Elisa, Oncogene Science, Cambridge, MA, USA). Currently, the HER-2 status of the tumour is evaluated either by morphological techniques, immunocytochemistry or fluorescent in situ hybridization. We studied serum HER-2 ECD before and after primary treatment in a series of 701 primary breast cancers at diagnosis and before first metastases ( N =128). At diagnosis, elevated HER-2 ECD (>12 ng/ml, cut-off level) was found in only 47 (6.7%) patients. Before first metastases, 45% of the samples were over 12 μg/l of HER-2 ECD (cut-off) and were significantly related with pre -and post treatment values ( P =0.0350 and P <0.0001 respectively). Concordance with CA 15.3 was 56.25% (weak correlation, rho =0.263). HER-2 ECD levels differed according to the sites of metastases ( P =0.0199, highest levels found in liver and lung). A median HER-2 ECD lead time of 254 days was found in 18/28 (64.3%) of recurring patients. Premetastatic HER-2 ECD levels showed a strong univariate (Kaplan-Meier method, P =0.0014) and multivariate prognostic values (Cox model, P <0.0001) for survival. We monitored the longitudinal changes in HER-2 ECD values of 33 women with metastatic breast cancer treated with trastuzumab and chemotherapy. Changes in HER-2 ECD serial concentrations reflected the clinical course of disease, increasing HER-2 ECD indicated breast cancer progression while decreasing serum values were indicative of response to therapy. We constructed a model (GEE, generalised estimated equation) that can be used to emulate patients’ response and we found pre-treatment HER-2 ECD to be predictive of the response to trastuzumab : when over 30ng/ml, pretreatment HER-2 ECD is predictive of treatment failure. In recurrent breast cancer, elevated levels of HER-2 ECD allow an early detection of occult metastases and the identification of patients with a high probability of shortened survival. Monitoring HER-2/ neu ECD levels during metastatic breast cancer can provide a real time assessment of a woman’s HER-2/ neu status and can provide important information for therapeutic decisions.

Epidermal Growth Factor Receptor Status in Breast Cancer Metastases to the Central Nervous System

Abstract Context.—The development of drug therapies (ZD1839) targeting epidermal growth factor receptor (EGFR) offers a pragmatic reason for exploring expression of EGFR in breast cancer, particularly metastatic breast cancer. There is a reported synergistic relationship between trastuzumab and ZD1839 therapy in patients with breast cancer. Although EGFR is the preferred dimerization partner for HER-2, it is unclear whether expression of these 2 interrelated receptors in a given patient with breast cancer would be parallel or mutually exclusive. Objectives.—To assess EGFR status in primary breast carcinoma versus metastatic central nervous system (CNS) sites and to compare results with HER-2/neu status in the same tumor. Design.—Central nervous system metastases (n = 51) from 33 patients and corresponding primary breast cancer specimens, when available (n = 11), were immunohistochemically stained for EGFR using a monoclonal mouse anti-EGFR antibody (clone 31G7) that recognizes both the wild-type form and the 145-kd variant III form of EGFR. The sections were evaluated by visual and image analysis techniques, and results were compared to previously assessed HER-2/neu status. Results.—Epidermal growth factor receptor expression was found in CNS metastases from 39% of patients, with 82% concordance between the EGFR status of the primary breast and metastatic sites, and 92% concordance between the EGFR status among multiple CNS metastases in a given patient. Epidermal growth factor receptor and HER-2/neu status were concordant at the primary site in only 45% of patients. Additionally, EGFR and HER-2/neu status were concordant among multiple CNS metastases per individual case in only 45% of patients. Conclusion.—Thirty-nine percent of patients with metastatic breast cancer express EGFR, with parallel expression between metastatic sites and the primary neoplasm in 82% of the cases. The discordance in 18% of the cases, however, suggests that anti-EGFR agents might not show equal efficacy against metastatic tumor deposits and the primary tumor within a given patient. An additional corollary for pathologists based on this nonhomogeneity of receptor expression is that both the primary breast and multiple metastatic tumor deposits may need to be individually assessed for EGFR status. In our study, most metastatic tumor deposits showed expression for either EGFR or HER-2/neu, and less often for both, implying that drug therapies could be individualized for patients based on test results for both receptors.

African-American/White differences in breast carcinoma: p53 alterations and other tumor characteristics.

Despite mounting evidence that breast tumors in African-American (AA) women are more aggressive compared with breast tumors in white (W) women, little is known regarding racial/ethnic differences in genetic alterations that may be of prognostic importance. In this population-based cohort of 322 AA women (45%) and W women (55%) who were diagnosed with breast carcinoma between 1987-1989, the authors evaluated available archived tumor tissue (n = 247 samples) for racial differences in selected genetic alterations and other prognostic indicators. Tumor characteristics were assessed by immunohistochemistry and/or expert review. Alterations in p53 were significantly more common in AA women compared with W women (odds ratio, 4.00; 95% confidence interval, 1.77-9.01) and remained statistically significant in models that were adjusted for disease stage at diagnosis, according to American Joint Committee on Cancer (AJCC) criteria, and for other prognostic indicators. No racial difference with regard to HER-2/neu status was observed, but alterations in c-met were more common in AA women once the model was adjusted for negative confounders (not significant). Among other tumor characteristics, significant findings included later AJCC stage and higher histologic and nuclear grade tumors in AA women. In addition, the burden of aggressive tumor characteristics was greater in AA women because they were more likely to be at high risk on multiple factors (e.g., both high histologic grade and high nuclear grade [P = 0.03] and negative status for both estrogen receptors and progesterone receptors [P = 0.01]). Data from this population-based cohort confirmed that breast tumors in AA women most likely are more aggressive compared with breast tumors in W women and offer new evidence for possible racial/ethnic differences with regard to p53 alterations.

Her-2/neu gene amplification and response to paclitaxel in patients with metastatic breast cancer.

HER-2/neu overexpression appears to be associated with improved response to anthracycline-based chemotherapy, but its association with response to taxane-based chemotherapy is unclear. In this retrospective subset analysis of patients with metastatic breast cancer enrolled in a randomized treatment trial, we investigated the response of patients with known HER-2/neu status to treatment with taxane-based epirubicin-paclitaxel (ET) chemotherapy compared with treatment with epirubicin-cyclophosphamide (EC) chemotherapy. HER-2/neu status (positive [i.e., HER-2/neu amplification] or negative [i.e., no HER-2/neu amplification]) of archival specimens of primary tumors from 297 patients with metastatic breast cancer was determined by use of fluorescence in situ hybridization. Associations between HER-2/neu status and the efficacy of randomly assigned chemotherapy (ET versus EC) were investigated. All statistical tests were two-sided. Patients with HER-2/neu-positive tumors had a statistically significantly greater objective response rate than patients with HER-2/neu-negative tumors to treatment with ET (76% versus 50%, respectively; P =.005) but not to treatment with EC (46% versus 33%; P =.130). The objective response rate associated with ET was greater than that associated with EC for both HER-2/neu-positive tumors (76% versus 46%; P =.004) and HER-2/neu-negative tumors (50% versus 33%; P =.002). However, the improvement in the objective response rate associated with ET, compared with that associated with EC, was greater for patients with HER-2/neu-positive tumors (adjusted odds ratio [OR] = 3.64, 95% confidence interval [CI] = 1.48 to 8.92; P=.005) than for patients with HER-2/neu-negative tumors (adjusted OR = 1.92, 95% CI = 1.01 to 3.64; P=.046). Among patients with HER-2/neu-positive tumors, those who received ET had better progression-free survival and overall survival than those who received EC (for progression-free survival, adjusted relative risk [RR] = 0.65, 95% CI = 0.42 to 1.02; P=.062; for overall survival, adjusted RR = 0.60, 95% CI = 0.36 to 1.02; P=.059). However, among patients with HER-2/neu-negative tumors, those who received ET and those who received EC had similar progression-free survival and overall survival. HER-2/neu amplification does not adversely influence response to first-line chemotherapy with either ET or EC. Furthermore, a taxane-containing regimen such as ET may provide a preferential benefit to patients with HER-2/neu-positive tumors.

Chromogenic in situ hybridization (CISH): a novel alternative in screening archival breast cancer tissue samples for HER-2/neu status.

BackgroundChromogenic in situ hybridization (CISH) is emerging as a practical, cost-effective, and valid alternative to fluorescent in situ hybridization in testing for gene alteration, especially in centers primarily working with immunohistochemistry (IHC).MethodsWe assessed Her-2/neu alteration using CISH on formalin-fixed paraffin-embedded primary invasive ductal carcinoma tumors in which IHC (CB11 antibody) had previously been performed, and we compared the results with IHC. The 160 selected cases were equally stratified randomly into the four IHC categories (scores of 0, 1+, 2+, and 3+). We also compared age at diagnosis and tumor histologic grade with IHC and CISH Her-2/neu.ResultsWe were able to perform and evaluate CISH successfully on all cases. The agreement between 3+ IHC and CISH-amplified cases as well as between all IHC and CISH Her-2/neu negative cases was 100%, and the concordance on all positive cases was 72.50%, with an overall agreement of 86.25%. All the discordant cases had 2+ IHC scores. Although we noted Her-2/neu positivity more in premenopausal women, the age at diagnosis was not significantly associated with IHC or CISH results. Similarly, although the small group of well-differentiated tumors was apparently Her-2/neu negative in both tests, no significant association was noted between any tumor histologic grade and either IHC or CISH results.ConclusionsCISH is easily integrated into routine testing in our laboratory. It is a necessary adjunct in determining the subset of non-amplified IHC-positive invasive tumors that will not benefit from trastuzumab therapy. Those cases with 2+ IHC results will be triaged and subjected to CISH. Her-2/neu testing should be done on all breast cancer cases regardless of age at presentation and tumor histologic grade.