Molecular detection of micrometastatic breast cancer in histopathology-negative axillary lymph nodes fails to predict breast cancer recurrence: a final analysis of a prospective multi-institutional cohort study.

BACKGROUND: To address the clinical relevance of molecular detection of occult breast cancer in sentinel lymph nodes and nonsentinel axillary lymph nodes (ALN), we initiated the Minimally Invasive Molecular Staging of Breast Cancer (MIMS) trial, a multi-institutional prospective cohort study. This trial represents the first prospective cohort study in which a multimarker, real-time reverse transcription polymerase chain reaction (RT-PCR) analysis was applied to the detection of breast cancer micrometastases in ALN. MATERIALS AND METHODS: Sentinel and/or nonsentinel ALN from 501 breast cancer subjects with T1-T3 primary tumors were analyzed by standard histopathology and multimarker, real-time RT-PCR analysis. Seven breast cancer-associated genes (mam, mamB, PIP, CK19, muc1, PSE, and CEA) known to be overexpressed in metastatic breast cancer compared with control lymph nodes were used. Follow-up data were collected for 5 years. RESULTS: Of the 501 breast cancer subjects enrolled, 348 were node negative and completed the 5-year follow-up. Of these patients (n = 94), 27% demonstrated evidence of molecular overexpression. The 5-year relapse-free survival rate was 95.4% (95% confidence interval [95% CI], 92.4-97.2%). No single gene or combination of study genes was predictive of recurrence. CONCLUSIONS: The genes in this study panel failed to be predictive of clinical relapse. This may be a function of several factors: the low event rate at 5 years, the particular gene set, the methodology used for detection/analysis or that our original hypothesis was wrong and that the presence of positive marker signal by real-time RT-PCR is not associated with a worsened clinical outcome.

The expression ratio of Map7/B2M is prognostic for survival in patients with stage II colon cancer.

Colorectal cancer (CRC) is the second most frequent cause of cancer-related death in the United States. To determine whether certain molecular markers might be prognostic for survival, we measured by quantitative real-time RT-PCR the expression levels of 15 previously studied genes that are known to be up-regulated or down-regulated in the progression of epithelial cancers. The tumor samples were extracted from formalin-fixed paraffin-embedded primary tissues derived from patients with Stage II CRC who developed disease recurrence within two years (n=10), or were disease-free for at least 4 years (n=12). We were able to determine, by AUC curve analysis, that the ratio of microtubule associated protein 7 (Map7)/B2M was predictive of outcome in our sample set. Further, using Kaplan-Meier survival analysis, we observed significantly different curves as a function of marker positivity for the Map7/B2M (p=0.0001; HR=11) expression ratio. This suggests that the expression ratio of Map7/B2M may serve as a valuable prognostic marker in patients with Stage II colon cancer, and potentially guide therapeutic decision making.

Detection of mammaglobin mRNA in peripheral blood is associated with high grade breast cancer: interim results of a prospective cohort study.

BACKGROUND: We sought to examine the detection rate of cancer cells in peripheral blood (PBL) and in bone marrow (BM) using an established 7-gene marker panel and evaluated whether there were any definable associations of any individual gene with traditional predictors of prognosis. METHODS: Patients with T1-T3 primary breast cancer were enrolled into a prospective, multi-institutional cohort study. In this interim analysis 215 PBL and 177 BM samples were analyzed by multimarker, real-time RT-PCR analysis designed to detect circulating and disseminated breast cancer cells. RESULTS: At a threshold of three standard deviations from the mean expression level of normal controls, 63% (136/215) of PBL and 11% (19/177) of BM samples were positive for at least one cancer-associated marker. Marker positivity in PBL demonstrated a statistically significant association with grade II-III (vs. grade I; p = 0.0083). Overexpression of the mammaglobin (mam) gene alone had a statistically significant association with high tumor grade (p = 0.0315), and showed a trend towards ER-negative tumors and a high risk category. There was no association between marker positivity in PBL and the pathologic (H&E) and/or molecular (RT-PCR) status of the axillary lymph nodes (ALN). CONCLUSION: This study suggests that molecular detection of circulating cancer cells in PBL detected by RT-PCR is associated with high tumor grade and specifically that overexpression of the mam gene in PBL may be a poor prognostic indicator. There was no statistically significant association between overexpression of cancer-associated genes in PBL and ALN status, supporting the concept of two potentially separate metastatic pathways.

An innovative microarray strategy identities informative molecular markers for the detection of micrometastatic breast cancer.

There is increasing evidence that molecular detection of micrometastatic breast cancer in the axillary lymph nodes (ALN) of breast cancer patients can improve staging. Molecular analyses of samples obtained from the Minimally Invasive Molecular Staging of Breast Cancer Trial (n = 489 patients) indicate that whereas the majority of molecular markers are informative for the detection of metastatic breast cancer (significant disease burden), only a few are sensitive for the detection of micrometastatic disease (limited disease burden). Frequency distribution and linear regression analyses reveal that relative levels of gene expression are highly correlated with apparent sensitivity for the detection of micrometastic breast cancer (P < 0.05). These data provides statistical validation of the concept that the most informative markers for detection of micrometastatic disease are those that are most highly expressed in metastatic disease. To test this hypothesis, we developed an innovative microarray strategy. RNA from a metastatic breast cancer ALN was diluted into RNA from a normal lymph node and analyzed using Affymetrix microarrays. Expression analysis indicated that only two genes [mammaglobin (mam) and trefoil factor 1 (TFF1)] were significantly overexpressed at a dilution of 1:50. Real-time reverse transcription-PCR analysis of pathology-negative ALN (n = 72) confirm that of all the markers tested, mam and TFF1 have the highest apparent sensitivity for detection of micrometastatic breast cancer. We conclude that a dilutional microarray approach is a simple and reliable method for the identification of informative molecular markers for the detection of micrometastatic cancer.

Accurate discrimination of Barrett's esophagus and esophageal adenocarcinoma using a quantitative three-tiered algorithm and multimarker real-time reverse transcription-PCR.

Esophageal adenocarcinoma (EA) is increasing faster than any other cancer in the U.S. In this report, we first show that EA can be distinguished from normal esophagus (NE) and esophageal squamous cell carcinoma by plotting expression values for EpCam, TFF1, and SBEM in three-dimensional Euclidean space. For monitoring progression of Barrett's esophagus (BE) to EA, we developed a highly sensitive assay for limited quantities of tissue whereby 50 ng of RNA are first converted to cDNA using 16 gene-specific primers. Using a set of training tissues, we developed a novel quantitative three-tiered algorithm that allows for accurate (overall accuracy = 61/63, 97%) discrimination of BE versus EA tissues using only three genes. The gene used in the first tier of the algorithm is TSPAN: samples not diagnosed as BE or EA by TSPAN in the first tier are then subjected to a second-tier analysis using ECGF1, followed by a third-tier analysis using SPARC. Addition of TFF1 and SBEM to the first tier (i.e., a five-gene marker panel) increases the overall accuracy of the assay to 98% (62/63) and results in mean molecular diagnostic scores (+/- SD) that are significantly different between EA and BE samples (3.19 +/- 1.07 versus -2.74 +/- 1.73, respectively). Our results suggest that relatively few genes can be used to monitor progression of BE to EA.

EpCAM is overexpressed in breast cancer and is a potential target for breast cancer gene therapy.

EpCAM (epithelial cell adhesion molecule) is a cell surface molecule that is known to be highly expressed in colon and other epithelial carcinomas. EpCAM is involved in cell-to-cell adhesion and has been the target of antibody therapy in several clinical trials. To assess the value of EpCAM as a novel target for breast cancer gene therapy, we performed real-time reverse transcription-PCR to quantify the level of EpCAM mRNA expression in normal breast tissue and primary and metastatic breast cancers. We found that EpCAM is overexpressed 100- to 1000-fold in primary and metastatic breast cancer. Silencing EpCAM gene expression with EpCAM short interfering RNA (siRNA) resulted in a 35-80% decrease in the rate of cell proliferation in four different breast cancer cell lines. EpCAM siRNA treatment decreased cell migration by 91.8% and cell invasion by 96.4% in the breast cancer cell line MDA-MB-231 in vitro. EpCAM siRNA treatment was also associated with an increase in the detergent-insoluble protein fraction of E-cadherin, alpha-catenin, and beta-catenin, consistent with the known biology of EpCAM as a regulator of cell adhesion. Our hypothesis is that modulation of EpCAM expression can affect cell migration, invasion, and proliferation by enhancing E-cadherin-mediated cell-to-cell adhesion. These data provide compelling evidence that EpCAM is a potential novel target for breast cancer gene therapy and offer insights into the mechanisms associated with EpCAM gene silencing.

Accurate molecular detection of non-small cell lung cancer metastases in mediastinal lymph nodes sampled by endoscopic ultrasound-guided needle aspiration.

OBJECTIVES: The recurrence of disease after the complete resection of early stage non-small cell lung cancer (NSCLC) indicates that undetected metastases were present at the time of surgery. Quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR) is a highly sensitive technique for detecting rare gene transcripts that may indicate the presence of cancer cells, and endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) is a minimally invasive technique for the nonoperative sampling of mediastinal lymph nodes. The aim of this study was to determine whether these two techniques could enhance the preoperative detection of occult metastases. METHODS: Patients with NSCLC were evaluated with chest CT and positron emission tomography scans. Those patients without evidence of metastases (87 patients) underwent EUS-guided FNA. Lymph nodes from levels 2, 4, 5, 7, 8, and 9 were sampled and evaluated by standard cytopathology and real-time RT-PCR. Normal control FNA specimens were obtained from patients without cancer who were undergoing EUS for benign disease (17 control specimens). For each sample, messenger RNA was extracted and real-time RT-PCR was used to quantitate the expression of six lung cancer-associated genes (ie, CEA, CK19, KS1/4, lunx, muc1, and PDEF) relative to the expression of an internal control gene (beta(2)-microglobulin). RESULTS: Clinical thresholds of marker positivity were set at 100% specificity, as determined by the receiver operating characteristic curve analysis. Of the cytology-positive lymph nodes (27 lymph nodes), the expression of the KS1/4 gene was above its respective clinical threshold in 25 of 27 samples (93%), making this the most sensitive marker for the detection of metastatic NSCLC. At least one of the six lung cancer-associated genes was overexpressed in 18 of 61 cytology-negative patients (30%), of which KS1/4 was overexpressed in 15 of 61 patients (25%). CONCLUSIONS: Based on the high accuracy of EUS-guided FNA/RT-PCR, we predict that some of the patients in the cytology-negative/marker-positive category will have high NSCLC recurrence rates. Among the genes used in our marker panel, KS1/4 appears particularly useful for the detection of overt or occult metastatic disease.

Molecular analysis improves sensitivity of breast sentinel lymph node biopsy: results of a multi-institutional prospective cohort study.

BACKGROUND: Pathologic evaluation may lack the sensitivity required for accurate staging of the axilla in breast cancer patients. We have completed enrollment of a multi-institutional prospective cohort study designed to determine if molecular analyses can improve axillary staging. In subset analyses, we have attempted to address the following questions: (1) Does molecular analysis improve the sensitivity of sentinel lymph node biopsy (SLNB) and (2) is the sentinel lymph node (SLN) hypothesis valid at the molecular level? METHODS: Four hundred eighty-nine subjects with T1, T2, or T3 breast cancer and no evidence of axillary lymph node (ALN) involvement were enrolled. ALNs were analyzed by routine pathology (hematoxylin-eosin staining), and by multimarker real-time reverse transcriptase-polymerase chain reaction analysis CRT-PCR to detect breast cancer metastases. Pathology and molecular data for both SLNs and nonsentinel ALNs were available for a subset of 207 subjects. RESULTS: The sensitivity of pathologic analysis of the SLN to predict the pathologic status of ALNs was 84.1%. The sensitivity of combining pathologic with molecular analysis of the SLN to predict the pathologic status of ALNs was 92.8%, a statistically significant increase in sensitivity (P = .031 by the McNemar test for correlated proportions). Finally, the sensitivity of combining pathologic with molecular analysis of the SLN to predict the pathologic or molecular status of ALNs was 85.4%. CONCLUSIONS: The combination of pathologic and molecular analysis of SLNs resulted in the highest sensitivity for prediction of the pathologic status of ALNs. The data also provide evidence that the SLN hypothesis remains valid at the molecular level.

Molecular detection of breast cancer cells in the peripheral blood of advanced-stage breast cancer patients using multimarker real-time reverse transcription-polymerase chain reaction and a novel porous barrier density gradient centrifugation technology.

PURPOSE: The goal of this study was to develop a molecular diagnostic assay to detect circulating breast cancer cells in the peripheral blood for the purpose of staging breast cancer. Our aim was to make available an assay that was not limited by the low concentration of circulating breast cancer cells and the background gene expression that is typically found in peripheral blood. EXPERIMENTAL DESIGN: In this study, we investigated the ability of two new technologies to significantly enhance the quantification of gene expression in the peripheral blood: enrichment by a novel porous barrier density gradient centrifugation technology; and multimarker real-time reverse transcription-PCR (RT-PCR). RESULTS: Using fluorescence-labeled breast cancer cells and flow cytometry, we show that processing peripheral blood by porous barrier density gradient centrifugation results in a 300-fold enrichment of breast cancer cells. Real-time RT-PCR analysis confirmed a concomitant reduction in background expression of the CK19 and MUC1 genes after enrichment. In a pilot study, porous barrier density gradient centrifugation and multimarker real-time RT-PCR enabled our laboratory to detect breast cancer-associated gene overexpression in 13 of 20 (65%) stage IV breast cancer patients. Nine of these 14 patients overexpressed three or more markers. CONCLUSIONS: These results confirm the promise of such a molecular diagnostic assay and suggest that additional studies are needed to precisely define the clinical relevance.

Lunx is a superior molecular marker for detection of non-small cell lung cancer in peripheral blood [corrected].

The clinical management of non-small cell lung cancer (NSCLC) would benefit greatly by a test that was able to detect small amounts of NSCLC in the peripheral blood. In this report, we used a novel strategy to enrich tumor cells from the peripheral blood of 24 stage I to IV NSCLC patients and determined expression levels for six cancer-associated genes (lunx, muc1, KS1/4, CEA, CK19, and PSE). Using thresholds established at three standard deviations above the mean observed in 15 normal controls, we observed that lunx (10 of 24, 42%), muc1 (5 of 24, 21%), and CK19 (5 of 24, 21%) were overexpressed in 14 of 24 (58%) peripheral blood samples obtained from NSCLC patients. Patients who overexpressed either KS1/4 (n = 2) or PSE (n = 1) also overexpressed either lunx or muc1. Of patients with presumed curable and resectable stage I to II disease (n = 7), at least one marker was overexpressed in three (43%) patients. In advanced stage III to IV patients (n = 17), at least one marker was overexpressed in 11 patients (65%). These results provide evidence that circulating tumor cells can be detected in NSCLC patients by a high throughput molecular technique. Further studies are needed to determine the clinical relevance of gene overexpression.

The molecular detection of micrometastatic breast cancer.

BACKGROUND: The rapid evolution of molecular technology and novel markers provides the opportunity to establish a more effective means to detect micrometastatic breast cancer. Given the controversies concerning application and clinical relevance, this review critically evaluates the current status of these molecular staging technologies. DATA SOURCES: Breast cancer literature addressing (1). molecular detection methodologies (immunohistochemistry, reverse transcriptase polymerase chain reaction, and microarray analysis); (2). specific tissue applications such as lymph nodes, bone marrow aspirate, and peripheral blood; (3). expert commentary concerning the clinical applications and pitfalls of these technologies; and (4). recent data from our molecular diagnostics laboratory. CONCLUSIONS: Molecular detection technologies such as reverse transcriptase polymerase chain reaction and microarray analyses are being developed that will likely have future application as cancer diagnostics. Further work is needed to establish assays that are validated by prospective clinical studies. Early identification of clinically relevant disease could lead to new treatment or staging approaches for breast cancer.

ZEB1-responsive genes in non-small cell lung cancer.

The epithelial to mesenchymal transition (EMT) is a developmental process enabling epithelial cells to gain a migratory mesenchymal phenotype. In cancer, this process contributes to metastases; however the regulatory signals and mechanistic details are not fully elucidated. Here, we sought to identify the subset of genes regulated in lung cancer by ZEB1, an E-box transcriptional repressor known to induce EMT. Using an Affymetrix-based expression database of 38 non-small cell lung cancer (NSCLC) cell lines, we identified 324 genes that correlated negatively with ZEB1 and 142 that were positively correlated. A mesenchymal gene pattern (low E-cadherin, high Vimentin or N-cadherin) was significantly associated with ZEB1 and ZEB2, but not with Snail, Slug, Twist1 or Twist2. Among eight genes selected for validation, seven were confirmed to correlate with ZEB1 by quantitative real-time RT-PCR in a series of 22 NSCLC cell lines, either negatively (CDS1, EpCAM, ESRP1, ESRP2, ST14) or positively (FGFR1, Vimentin). In addition, over-expression or knockdown of ZEB1 led to corresponding changes in gene expression, demonstrating that these genes are also regulated by ZEB1, either directly or indirectly. Of note, the combined knockdown of ZEB1 and ZEB2 led to apparent synergistic responses in gene expression. Furthermore, these responses were not restricted to artificial settings, since most genes were similarly regulated during a physiologic induction of EMT by TGF-ß plus EGF. Finally, the absence of ST14 (matriptase) was linked to ZEB1 positivity in lung cancer tissue microarrays, implying that the regulation observed in vitro applies to the human disease. In summary, this study identifies a new set of ZEB-regulated genes in human lung cancer cells and supports the hypothesis that ZEB1 and ZEB2 are key regulators of the EMT process in this disease.

A quantitative reverse transcription-PCR assay for rapid, automated analysis of breast cancer sentinel lymph nodes.

We have previously reported that a quantitative reverse transcription (QRT)-PCR assay accurately analyzes sentinel lymph nodes (SLNs) from breast cancer patients. The aim of this study was to assess a completely automated, cartridge-based version of the assay for accuracy, predictive value, and reproducibility. The triplex (two markers + control) QRT-PCR assay was incorporated into a single-use cartridge for point-of-care use on the GeneXpert system. Three academic centers participated equally. Twenty-nine positive lymph nodes and 30 negative lymph nodes were analyzed to establish classification rules. SLNs from 120 patients were subsequently analyzed by QRT-PCR and histology (including immunohistochemistry), and the predetermined decision rules were used to classify the SLNs; 112 SLN specimens produced an informative result by both QRT-PCR and histology. By histological analysis, 21 SLNs were positive and 91 SLNs were negative for metastasis. QRT-PCR characterization produced a classification with 100% sensitivity, 97.8% specificity, and 98.2% accuracy compared with histology (91.3% positive predictive value and 100% negative predictive value). Interlaboratory reproducibility analyses demonstrated that a 95% prediction interval for a new measurement (DeltaCt) ranged between 0.403 and 0.956. This fully automated QRT-PCR assay accurately characterizes breast cancer SLNs for the presence of metastasis. Furthermore, the assay is not dependent on subjective interpretation, is reproducible across three clinical environments, and is rapid enough to allow intraoperative decision making.

A simple two-gene prognostic model for adenocarcinoma of the lung.

OBJECTIVE: We hypothesized that clinical outcome of resected early-stage adenocarcinoma of the lung can be predicted by the expression of a few critically important genes as measured by quantitative real-time reverse-transcriptase polymerase chain reaction in formalin-fixed paraffin-embedded primary tumors. METHODS: Twenty-two prognostic genes for the metastatic phenotype were identified through complementary DNA microarray analysis of 4 cancer cell lines and bioinformatics analysis. Expression levels of a subset of these genes (n = 13) were measured by real-time time reverse-transcriptase polymerase chain reaction in formalin-fixed paraffin-embedded primary adenocarcinoma from patients whose disease recurred within 2 years (n = 9) and in patients who did not have a recurrence (n = 11). Receiver operating characteristic curves were analyzed to establish prognostic values of single genes. The most informative gene was combined with the remaining genes to determine whether there was a particular pair(s) that yielded high diagnostic accuracy. A small validation study was performed. RESULTS: Receiver operating characteristic curve analysis of the single genes revealed that high expression of CK19 was associated with nonrecurrence (area under the curve = 0.859, confidence interval = 0.651-0.970). The CK19/EpCAM2 gene ratio had the most reproducible prognostic accuracy, followed by the CK19/P-cadherin ratio. A Kaplan-Meier survival analysis generated from the CK19/EpCAM2 ratio resulted in highly significant curves as a function of marker positivity (P = .0007; hazard ratio = 10.7). Significance declined but was maintained in the validation study. CONCLUSIONS: This preliminary study provides evidence that the CK19/EpCAM2 and/or CK19/P-cadherin ratio(s) may be a simple and accurate prognostic indicator of clinical outcome in early-stage adenocarcinoma of the lung. If further validation studies from large patient cohorts confirm the results, adjuvant therapy could be targeted to this high-risk group.

Accurate discrimination of pancreatic ductal adenocarcinoma and chronic pancreatitis using multimarker expression data and samples obtained by minimally invasive fine needle aspiration.

To augment cytological diagnosis of pancreatic ductal adenocarcinoma (PDAC) in tissue samples obtained by minimally invasive endoscopic ultrasound-guided fine needle aspiration, we investigated whether a small set of molecular markers could accurately distinguish PDAC from chronic pancreatitis (CP). Expression levels of 29 genes were first determined by quantitative real-time RT-PCR in a training set of tissues in which the final diagnosis was PDAC (n=20) or CP (n=10). Using receiver operator characteristic curve analysis, we determined that the single gene with the highest diagnostic accuracy for discrimination of CP vs. PDAC in the training study was urokinase plasminogen activator receptor (UPAR; AUC value = 0.895, 95% CI=0.728-0.976). In the set of test tissues (n=14), the accuracy of UPAR decreased to 79%. However, we observed that the addition of 6 genes (EPCAM2, MAL2, CEA5, CEA6, MSLN and TRIM29; referred to as the 6-gene classifier) to UPAR resulted in high accuracy in both training and testing sets. Excluding 3 samples (out of 44; 7%) for which results of the UPAR/6-gene classifier were "undefined," the accuracy of the UPAR/6-gene classifier was 100% in training samples (n=29), 92% in 12 test samples (p=0.004 that results were randomly generated; p=0.046 that the UPAR/6-gene classifier was comparable to UPAR alone; chi2 test), 100% in 3 samples for which the initial cytological diagnosis was "suspicious" and 98% (40/41) overall. Our results provide evidence that molecular marker expression data can be used to augment cytological analysis.

Esophageal cancer disparities in South Carolina: early detection, special programs, and descriptive epidemiology.

Because of its high fatality rate and our inability to detect esophageal disease early in its development, esophageal cancer represents a significant medical and public health challenge. The mortality statistics underline the importance of focusing on prevention of these conditions as a matter of state and national public health priority. Unfortunately, the measures needed for primary prevention of these conditions do not seem as clear-cut for populations at highest risk of this disease (i.e., AAs) as for the populations represented in most epidemiologic studies. Our incomplete knowledge about the etiology of esophageal cancer, especially squamous cell carcinomas in AAs and adenocarcinomas in EAs, preclude developing and disseminating effective preventive measures. Clearly, the prevention and control of esophageal cancers represent a different paradigm compared to other tobacco-related cancers of the upper aerodigestive tract. Data from a number of studies indicate that disparities exist in esophageal cancer incidence between racial groups and between geographical locations within South Carolina, and that these disparities are continuing to increase. The reasons for these disparities are only beginning to receive attention. They probably will be found to be complex and multifaceted. A combination of genetic factors, environmental influences (e.g., those related to diet), and the deleterious changes associated with smoking and alcohol consumption are the obvious parameters that should be the focus of initial epidemiologic data collection and assessment. Issues around dietary assessment, a major area of expertise among researchers in South Carolina, must be addressed in these studies. Much remains to be done for us to understand how research, health care, and educational efforts in the state of South Carolina might influence the detection, care, treatment, and, ultimately, reduction in esophageal cancer incidence and mortality rates. An important step in the process will be to coordinate data-collection efforts between clinicians, researchers, and concerned community members in South Carolina. This would allow comprehensive background profiles of patients to be collected for studies ranging from those focusing on the basic biology of the disease and its etiology to those aimed at understanding the role of health services and the effect of policy. In order to design and implement the full range of research needed to understand what we can do to prevent and control esophageal cancer in our state, it is our intention to engage all of the stakeholders within South Carolina; including community members, cancer survivors, cancer care providers, researchers, and individuals at high risk of esophageal cancer. With its large proportion of rural, socioeconomically deprived African Americans, what is learned about esophageal cancer in South Carolina will have national, and perhaps international, relevance.

Breast cancer disparities in South Carolina: early detection, special programs, and descriptive epidemiology.

A discrepancy exists between mortality and incidence rates between African-American and European-American women in South Carolina. The relationship between tumor grade and the estrogen/ progesterone receptor status is different in African-American and European-American women. African-American women with breast cancer should be encouraged to participate in clinical trials, with the goal of identifying biological factors that might facilitate the detection of tumors at an earlier stage and the development of more effective therapies. The most important of our goals is to design studies to reduce the incidence of the disease and interventions to improve survival and quality of life. The importance of participation in research cannot be overstated. Reproductive factors such as early pregnancy and multiple pregnancies are strongly related to breast cancer risk, however, promotion of these factors as a "prevention strategy," clearly does not lead to cogent, comprehensive public health messages. Data from ecological and migrant studies point clearly to other factors that may be important such as diet. Additional research around primary prevention strategies is needed. In addition, yearly mammograms (secondary prevention) are recommended for women over 50 years old or those with relatives who have developed breast cancer. The Best Chance Network, as a provider of screenings to low-income, uninsured women, has helped to narrow the racial gap in screening that otherwise might exist (see Figures 3 and 4) to a large extent. The determination for timing of surgery after diagnosis needs additional consideration. For example, factors such as effective screening in younger women, timing of screening and surgery in relationship to the ovulatory cycle, and season of screening and surgery may have a great impact on outcomes and may offer some insight into the process of carcinogenesis and therapeutic efficacy. Research into this area is so novel that the impact on possible ethnic disparities is completely unknown. The South Carolina Cancer Disparities Community Network (SCCDCN) has identified the following areas as potential research foci: Identification of small media interventions as an effective strategy to motivate targeted populations, especially those least likely to seek screening for breast cancer and those least likely to participate in research programs (African-Americans). Utilization of breast cancer survivors, self-identified as community natural helpers, can share their experiences with their church congregation. A replication of such a program in South Carolina has great potential because of the strong presence of the church, especially in rural parts of the state. Programs that closely integrate religion with screening women for breast cancer are promising in this state. Development of a mammography registry whereby information on all mammography procedures would be collected within a single database system (much like a central cancer registry). This would aid in identifying population groups that could be targeted for special programs and in the examination and exploration of the most appropriate modalities of detection. Such a resource could also be a useful tool to encourage screening. Thus, this focus area has the potential to benefit epidemiologic and health promotion research on many different levels. Additional breast cancer screening methods should not be overlooked as a potential research focus. Mammography is not the only valid screening method for breast cancer. Magnetic resonance imaging has shown some promise for screening among women with a genetic predisposition for cancer. Another promising avenue is thermography. Because detection rates may depend on age, ethnicity, and breast mammographic characteristics, women for whom regular screening methods do not detect their cancers (e.g. older age, African-American ethnicity, dense breasts) must be identified and other screening methods promoted within these populations. The above-mentioned mammography registry would support this type of research.

Detection of telomerase expression in mediastinal lymph nodes of patients with lung cancer.

Mediastinal lymph nodes are the most common site of tumor spread in non-small cell lung cancer (NSCLC). We hypothesized that micrometastatic disease could be detected by reverse transcription-polymerase chain reaction (RT-PCR) for expression of human telomerase reverse transcriptase (hTERT) in mediastinal lymph nodes and that a minimally invasive technique (endoscopic ultrasound-guided fine-needle aspiration [EUS-FNA]) is capable of sampling lymph nodes for PCR analysis without surgery. Mediastinal lymph nodes were sampled with EUS-FNA in patients with NSCLC and negative control subjects undergoing EUS for benign disease. Total RNA was harvested from samples, and RT-PCR was performed to detect telomerase gene expression. RNA was available from 87 of 100 lymph node aspirates from 39 patients with NSCLC and from 12 negative control patients. hTERT was expressed in 0 of 14 negative control lymph nodes in 18 of 57 pathologically negative lymph nodes from cancer patients and in 10 of 16 pathologically positive lymph nodes (p < 0.05). Five of 18 (28%) patients with no pathologically evident mediastinal disease expressed telomerase in at least one lymph node. Minimally invasive EUS-FNA with RT-PCR is capable of detecting expression of cancer specific mRNA in lymph nodes. Approximately one-third of pathologically negative mediastinal lymph nodes in NSCLC patients express hTERT mRNA. The clinical significance of this observation is yet to be determined.

Molecular detection of micrometastatic breast cancer in histopathology-negative axillary lymph nodes correlates with traditional predictors of prognosis: an interim analysis of a prospective multi-institutional cohort study.

OBJECTIVE: We sought to establish the clinical relevance of micrometastatic disease detected by reverse transcription polymerase chain reaction (RT-PCR) in axillary lymph nodes (ALN) of breast cancer patients. BACKGROUND: The presence of ALN metastases remains one of the most valuable prognostic indicators in women with breast cancer. However, the clinical relevance of molecular detection of micrometastatic breast cancer in sentinel lymph nodes (SLN) and nonsentinel ALN has not been established. METHODS: Four hundred eighty-nine patients with T1-T3 primary breast cancers were analyzed in a prospective, multi-institutional cohort study. ALN were analyzed by standard histopathology (H&E staining) and by multimarker, real-time RT-PCR analysis (mam, mamB, muc1, CEA, PSE, CK19, and PIP) designed to detect breast cancer micrometastases. RESULTS: A positive marker signal was observed in 126 (87%) of 145 subjects with pathology-positive ALN, and in 112 (33%) of 344 subjects with pathology-negative ALN. In subjects with pathology-negative ALN, a positive marker signal was significantly associated with traditional indicators of prognosis, such as histologic grade (P = 0.0255) and St. Gallen risk category (P = 0.022). Mammaglobin was the most informative marker in the panel. CONCLUSION: This is the first report to show that overexpression of breast cancer-associated genes in breast cancer subjects with pathology-negative ALN correlates with traditional indicators of disease prognosis. These interim results provide strong evidence that molecular markers could serve as valid surrogates for the detection of occult micrometastases in ALN. Correlation of real-time RT-PCR analyses with disease-free survival in this patient cohort will help to define the clinical relevance of micrometastatic disease in this patient population.