Tissue microarrays for comparing molecular features with proliferation activity in breast cancer.

Tissue microarrays (TMAs) are potentially suited to find associations between molecular features and clinical outcome. Enhanced cell proliferation, as measured by Ki67 immunohistochemistry, is related to poor patient prognosis in many different tumor types. Ki67 expression shows considerable intratumoral heterogeneity. It is unclear if the TMA format is suitable for the analysis of potentially heterogeneous markers because of the small size of TMA spots. We have analyzed a breast cancer TMA containing 2,517 breast tissues, including 2,222 neoplastic and 295 normal or premalignant samples, for Ki67 labeling index (Ki67 LI) and additional markers with a known relationship to Ki67 LI by immunohistochemistry (ER, PR, Bcl-2, Egfr, p16, p53) and Fluorescence in situ hybridization (HER2, MDM2, CCND1, MYC). A high Ki67 LI was linked to tumor phenotype including grade (p < 0.0001), stage (p < 0.0001), nodal stage (p = 0.0018), and patient prognosis (p < 0.0001), elevated protein levels of p53, p16 and Egfr, reduced levels of Bcl2, ER, and PR (p < 0.0001 each), as well as amplifications of HER2, MYC, CCND1 and MDM2 (p < 0.0001 each). In summary, all expected associations between Ki67 and the analyzed molecular markers could be reproduced with high statistical significance using a TMA containing only one tissue sample per tumor, measuring 0.6 mm in diameter. We conclude that associations with cell proliferation can be reliably analyzed in a TMA format.

Predominance of high-grade pathway in breast cancer development of Middle East women.

Recent data have suggested considerable molecular differences in cancers from various ethnical groups. As molecular features are increasingly used for predicting cancer prognosis and response to therapy, better knowledge of ethnic molecular features is important. To identify potential molecular differences between breast cancers in Europe and the Middle East, we analyzed consecutive breast cancer series from Switzerland (n=2197) and Saudi Arabia (n=204). Tissue microarrays were analyzed by fluorescence in situ hybridization for HER2, CCND1, MYC, and EGFR amplification. The data revealed marked differences between Saudi and Swiss patients. Saudi breast cancers had a markedly higher frequency of HER2 (31 vs 17%; P<0.0001) and MYC (16 vs 5%; P<0.0001) amplifications than Swiss breast cancers. Remarkably, this was partly due to a much higher incidence of grade 3 cancers in the Saudi than in the Swiss population (65 vs 32%; P<0.0001). However, differences in amplification frequency hold also true within grade 3 cancers (HER2: 40 vs 30%, P<0.05; MYC: 22 vs 11%, P=0.002). Interestingly, in combination with known age standardized incidence rates of breast cancer in Saudi Arabia (21.6/100 000) and Switzerland (70.1/100 000), these data suggest that the incidence of high-grade breast cancer is comparable for Saudi and Swiss women, while the incidence of low-grade breast cancers is about 14 times lower in Saudi than for Swiss women. These observations suggest that a difference in genetic susceptibility and/or lifestyle between Saudi and Swiss women has a substantial and much higher than expected impact on the risk of low-grade breast cancer.

Prognostic relevance of gene amplifications and coamplifications in breast cancer.

Multiple different oncogenes have been described previously to be amplified in breast cancer including HER2, EGFR, MYC, CCND1, and MDM2. Gene amplification results in oncogene overexpression but may also serve as an indicator of genomic instability. As such, presence of one or several gene amplifications may have prognostic significance. To assess the prognostic importance of amplifications and coamplifications of HER2, EGFR, MYC, CCND1, and MDM2 in breast cancer, we analyzed a breast cancer tissue microarray containing samples from 2197 cancers with follow-up information. Fluorescence in situ hybridizations revealed amplifications of CCND1 in 20.1%, HER2 in 17.3%, MDM2 in 5.7%, MYC in 5.3%, and EGFR in 0.8% of the tumors. All gene amplifications were significantly associated with high grade. HER2 (P < 0.001) and MYC amplification (P < 0.001) were also linked to shortened survival. In case of HER2, this was independent of grade, pT, and pN categories. MYC amplification was almost 3 times more frequent in medullary cancer (15.9%), than in the histologic subtype with the second highest frequency (ductal; 5.6%; P = 0.0046). HER2 and MYC amplification were associated with estrogen receptor/progesterone receptor negativity (P < 0.001) whereas CCND1 amplification was linked to estrogen receptor/progesterone receptor positivity (P < 0.001). Coamplifications were more prevalent than expected based on the individual frequencies. Coamplifications of one or several other oncogenes occurred in 29.6% of CCND1, 43% of HER2, 55.7% of MDM2, 65% of MYC, and 72.8% of EGFR-amplified cancers. HER2/MYC-coamplified cancers had a worse prognosis than tumors with only one of these amplifications. Furthermore, a gradual decrease of survival was observed with increasing number of amplifications. In conclusion, these data support a major prognostic impact of genomic instability as determined by a broad gene amplification survey in breast cancer.

Signal transducer and activator of transcription-5 activation and breast cancer prognosis.

PURPOSE: Transcription factor signal transducer and activator of transcription-5 (Stat5) promotes breast epithelial cell differentiation. We retrospectively analyzed whether levels of active Stat5 in breast cancer were linked to clinical outcome. MATERIALS AND METHODS: Immunohistochemistry was used to detect active, tyrosine-phosphorylated Stat5 in paraffin-embedded breast cancer specimens from three archival tissue microarray materials A, B, and C. Material A included 19 healthy human breast tissues and a progression series of primary lymph node-negative, primary lymph node-positive, and metastatic breast cancer (n = 400). Materials B (n = 785) and C (n = 570) represented two independent arrays of unselected primary breast cancer specimens with clinical follow-up data. RESULTS: Material A demonstrated that Stat5 activation, but not Stat5 protein expression, was gradually lost during cancer progression, with detectable activation in 100% of healthy breast specimens compared with less than 20% of node-positive breast cancers and metastases. Stat5 activation in tumors of material B was associated with favorable prognosis. This observation was confirmed and extended in material C to include both breast cancer-specific survival and disease-free survival. Stat5 activation remained an independent prognostic marker after adjusting for patient age, tumor size, histological grade, estrogen receptor, progesterone receptor, and Her2/neu status by Cox multivariate analysis (hazard ratio, 2.0; P =.029). Stat5 activation was a particularly favorable marker in the lymph node-negative breast cancer subpopulation (hazard ratio, 7.5; P =.003). CONCLUSION: In our study, active Stat5 distinguishes breast cancer patients with favorable prognosis, and may be a useful marker for selection of more individualized treatment, especially in localized disease. These findings require confirmation in a large prospective study.

KIT (CD117)-positive breast cancers are infrequent and lack KIT gene mutations.

PURPOSE: KIT (CD117) is a transmembrane tyrosine kinase representing a target for STI571 (Glivec) therapy. Some KIT-overexpressing solid tumors have responded favorably to STI571, potentially because of the presence of KIT-activating mutations. EXPERIMENTAL DESIGN: To investigate the epidemiology of KIT overexpression and mutations, we investigated a series of 1654 breast cancers. All tumors were analyzed by immunohistochemistry in a tissue microarray format. RESULTS: KIT expression was always present in normal breast epithelium. However, cancer analysis revealed the only 43 of 1654 (2.6%) tumors were KIT-positive. KIT expression was more frequent in medullary cancer (9 of 47 positive; 19.1%) than in any other histological tumor subtype (P < 0.001). KIT expression was significantly associated with high tumor grade (P < 0.0001) but unrelated to pT and pN categories or patient survival. Mutation analysis of exons 2, 8, 9, 11, 13, and 17 was negative in 10 KIT-positive tumors. CONCLUSIONS: Overall, our data show that a high level of KIT expression occurs infrequently in breast cancer. KIT-positive breast cancers may not reflect "KIT up-regulation" because KIT is also expressed in normal breast epithelium. The lack of KIT mutations also argues against the therapeutic efficacy of STI571 in breast cancer.

Pleural mesothelioma incidence in Europe: evidence of some deceleration in the increasing trends.

OBJECTIVE: To summarize the geographical and temporal variations in incidence of pleural mesothelioma in Europe, using the extensive data available from European general cancer registries, and consider these in light of recent trends in asbestos extraction, use and import in European countries. MATERIAL AND METHODS: The data were extracted from the European Cancer Incidence and Mortality database (EUROCIM). The inclusion criteria was acceptance in Volume VII of Cancer Incidence in Five Continents. Truncated age-standardized rates per 100,000 for the ages 40-74 were used to summarise recent geographical variations. Standardized rate ratios and 95% confidence intervals for the periods 1986-1990 and 1991-1995 were compared to assess geographical variations in risk. To investigate changes in the magnitude of most recent trends, regression models fitted to the latest available 10-year period (1988-1997) were compared with trends in the previous decade. Fitted rates in younger (40-64) and older adults (65-74) in the most recent period were also compared. RESULTS: There was a great deal of geographical variation in the risk of mesothelioma, annual rates ranging from around 8 per 100,000 in Scotland, England and The Netherlands, to lower than 1 per 100,000 in Spain (0.96), Estonia (0.85), Poland (0.85) and Yugoslavia, Vojvodina (0.56) among men. The rank of the rates for women was similar to that observed for men, although rates were considerably lower. Between 1978 and 1987, rates in men significantly increased in all countries (excepting Denmark). In the following 10 years, there was a deceleration in trend, and a significant increase was detectable only in England and France. In addition, the magnitude of recent trends in younger men was generally lower than those estimated for older men, in both national and regional cancer registry settings. CONCLUSIONS: While mesothelioma incidence rates are still rising in Europe, a deceleration has started in some countries. A decrease may begin in the next few years in certain European populations considering the deceleration of observed trends in mesothelioma and asbestos exposure, as well as the recent ban on its use.

DNA copy number changes in cervical adenocarcinoma.

PURPOSE: There is evidence that specific genetic events are involved in the initiation and progression of squamous cell carcinoma of the uterine cervix. The genotype-phenotype correlations in cervical adenocarcinoma (AC) are unclear. EXPERIMENTAL DESIGN: Comparative genomic hybridization was applied to screen for DNA copy number gains and losses in 22 cervical ACs of clinical stage IB. IHC was performed in all of the samples to determine HER-2/neu expression (HercepTest). RESULTS: The most frequent copy number alterations were DNA sequence gains of chromosome 17q (54%). HER-2/neu expression (score 2+) was immunohistochemically detected in 2 of 22 tumors. DNA sequence losses were most prevalent on chromosomes Xq (50%), Xp (36%), 18q (36%), and 4q (36%). DNA sequence losses of chromosome 18q were associated significantly with poor prognosis in cervical AC (P < 0.01). CONCLUSIONS: DNA sequence copy number gains of chromosome 17q are frequent events in ACs of the cervix. However, gains on 17q are not associated with HER-2/neu expression in cervical ACs. The inactivation of tumor suppressor genes on chromosome 18q might be responsible for the progression of both cervical AC and cervical squamous cell carcinoma.

PTEN as a molecular marker to distinguish metastatic from primary synchronous endometrioid carcinomas of the ovary and uterus.

The distinction between two primary carcinomas on the one hand and a metastatic disease on the other hand in patients suffering from synchronous endometrioid carcinomas of the uterus and ovary is difficult. Exclusive histopathologic analysis appears to be insufficient and sometimes misleading. The tumor suppressor PTEN was found to be important in early neoplastic transformation in endometrioid carcinomas of the uterus. In this study, we screened synchronous endometrioid carcinomas of the uterus and ovary of 10 patients for loss of heterozygosity using seven different microsatellite markers at 10q23.3 and for mutations in the entire coding region of PTEN. Point mutations or microdeletions/insertions were found in six patients. Allelic loss at 10q23.3 was detected in eight patients. Based on conventional histology, a metastatic disease was diagnosed in seven patients and a concomitant uterine and ovarian carcinoma in three patients. After molecular analysis, the histopathologic diagnosis of three patients had to be revised. Histopathology represents the standard method to process tumor specimens from these patients. Nevertheless, mutation screen for PTEN and LOH analysis at 10q23.3 provide helpful genetic tools to establish a correct final diagnosis, which is important in view of prognosis and therapeutic implications.

HIV-testing and newly-diagnosed malignant lymphomas. The SAKK 96/90 registration study.

The association of Non-Hodgkin Lymphoma (NHL) and HIV-infection was soon recognized and the Center of Disease Control (CDC) has classified some types of NHL as AIDS-defining illnesses (ADI). Hodgkin's disease (HD) represents the most common type of non ADI malignancy in HIV-infected cases. Commonly, data on malignant lymphoma in this population is collected in known HIV-positive patients or in autopsy-series. This registration study was designed to estimate the incidence of HIV-positivity in patients with newly diagnosed malignant lymphoma. A registration of all patients with newly diagnosed malignant lymphoma and their HIV-status was performed in every center of the Swiss Group for Clinical Cancer research (SAKK) from January 1, 1991 to July 31, 1993. Among 474 eligible patients, HIV-status was evaluated in 400 and 52 were tested positive (13%), 42 (81%) of them males. Three of them were newly detected cases (after lymphoma-diagnosis). Three hundred and forty patients (72%) presented with NHL, 42 (12.4%) of them HIV-positive; 33 out of these had aggressive lymphoma. B-symptoms were significantly more frequent in HIV-positive patients. In the 134 patients with HD, 10 (7.5%) tested HIV-positive, mostly presenting with stage IV disease (7), B-symptoms (9) and extranodal disease (7). In conclusion, 13% out of 400 evaluated patients with newly diagnosed malignant lymphoma tested HIV-positive. The study confirms the predominance of aggressive lymphoma histologies and frequent presentation with B-symptoms in HIV-positive patients with NHL. Male gender, young age (26-35 years) and B-symptoms are prognostic factors for HIV-positivity in NHL.

Expression of cytokeratins 17 and 5 identifies a group of breast carcinomas with poor clinical outcome.

While several prognostic factors have been identified in breast carcinoma, the clinical outcome remains hard to predict for individual patients. Better predictive markers are needed to help guide difficult treatment decisions. In a previous study of 78 breast carcinoma specimens, we noted an association between poor clinical outcome and the expression of cytokeratin 17 and/or cytokeratin 5 mRNAs. Here we describe the results of immunohistochemistry studies using monoclonal antibodies against these markers to analyze more than 600 paraffin-embedded breast tumors in tissue microarrays. We found that expression of cytokeratin 17 and/or cytokeratin 5/6 in tumor cells was associated with a poor clinical outcome. Moreover, multivariate analysis showed that in node-negative breast carcinoma, expression of these cytokeratins was a prognostic factor independent of tumor size and tumor grade.

Telomerase as a prognostic marker in breast cancer: high-throughput tissue microarray analysis of hTERT and hTR.

Telomerase activity (TA) has been shown to correlate with poor clinical outcome in various tumour entities, indicating that tumours expressing this enzyme may be more aggressive and that TA may be a useful prognostic marker. For breast cancer, however, TA is a controversial prognostic marker; whereas some studies suggest an association between TA and disease outcome, others do not find this association. This study used tissue microarrays (breast carcinoma prognosis arrays) containing 611 samples (each 0.6 mm in diameter) from the tumour centre of paraffin-embedded breast carcinomas to analyse the catalytic subunit of telomerase, human telomerase reverse-transcriptase (hTERT), and the internal RNA component (hTR), which are the core components of the telomerase holoenzyme complex. hTERT protein expression was obtained by immunohistochemistry (human anti-telomerase antibody Ab-2, Calbiochem), and hTR RNA was measured by radioactive in situ hybridization. hTERT and hTR expression were determined semi-quantitatively and graded (scores 1-4). Clinical data, such as histological subtype, pT stage, tumour diameter, pN stage, BRE grade, tumour-specific survival (in months), patient's age and others, were available for statistical analysis. A statistically significant correlation was found between tumour-specific survival (overall survival) and hTERT expression (p < 0.0001) or hTR expression (p = 0.00110). Tumours with higher scores (scores 3, 4) for hTR and/or hTERT were associated with a worse prognosis. In multivariate analysis, hTERT expression was an independent prognostic factor. Previous studies, focusing on analysis of TA in smaller numbers of fresh-frozen breast carcinomas by the TRAP assay, gave controversial results with respect to TA as a prognostic marker. Using tissue microarrays from 611 breast carcinomas, this study has demonstrated that increased expression levels of the telomerase core components, hTERT and hTR, are associated with lower overall survival. These findings suggest that TA should be included in future validation studies as a prognostic marker in breast cancer.

DNA sequence losses on chromosomes 11p and 18q are associated with clinical outcome in lymph node-negative ductal breast cancer.

PURPOSE: Histological and other markers alone cannot predict the risk of disease progression in node-negative breast cancer. Several genomic aberrations have been linked to clinical outcome in breast cancer. EXPERIMENTAL DESIGN: In this study, comparative genomic hybridization was applied to screen for specific DNA copy number gains and losses in 20 pT1/pT2 node-negative invasive ductal carcinomas with no disease recurrence with at least 8 years of follow-up and in 20 pT1/pT2 node-negative tumors with distant disease recurrence. RESULTS: The number of genomic aberrations (copy number gains and losses) per tumor was significantly higher in tumors with disease recurrence (P < 0.05). The number of genomic aberrations was associated with histological grade (P < 0.02). Within the group of tumors with disease recurrence, the total number of genetic aberrations per tumor (P < 0.02) and the number of DNA sequence losses per tumor (P < 0.01) were significantly associated with poor survival. Of the individual loci involved, only losses at chromosomes 11p (P < 0.002) and 18q (P < 0.004) were associated with poor survival in the recurrence group. Histological grade and loss of 18q were independent prognostic variables in multivariate analysis. CONCLUSIONS: This genome-wide analysis by comparative genomic hybridization suggests that node-negative ductal breast cancers with a high number of genomic aberrations have an increased risk of disease recurrence. The number of DNA sequence losses, particularly losses of chromosomes 11p and 18q, were associated with poor prognosis. Genes on chromosomes 11p and 18q may play a role in the progression of ductal breast carcinoma.

Selective axillary surgery in breast cancer patients based on positron emission tomography with 18F-fluoro-2-deoxy-D-glucose: not yet!

We prospectively evaluated 31 patients with invasive breast cancer. Preoperative positron emission tomography (PET) with 18F-fluoro-2-deoxy-D-glucose (18F-FDG) for detection of axillary lymph node metastases was compared with the histopathologic status of the sentinel lymph node (SLN). Sensitivity of PET imaging was 43%, specificity and negative predictive value were 94 and 67%, respectively. The smallest metastasis detected by PET measured 3 mm in diameter. The results of this study suggest that detection of small axillary lymph node metastases is limited by the currently achievable spatial resolution of PET imaging. Selective axillary surgery in breast cancer patients based on 18F-FDG PET is yet not possible.