Monoclonal Antibody Ber-EP4 Research Articles

Is Minimal Residual Lymph Node Disease in Papillary Thyroid Cancer of Prognostic Impact? An Analysis of The Epithelial Cell Adhesion Molecule EpCAM in Lymph Nodes of 40 pN0 Patients

This study was aimed to assess the extend of nodal microdissemination in patients with pN0 papillary thyroid carcinoma (PTC) using immunohistochemical analysis. In early stage PTC both, systematic lymphadenectomy as well as radio iodine treatment, aimed to eliminate occult nodal tumor involvement, are under controversial debate, since little is known about the extend of lymphatic microdissemination in these patients. Formalin embedded samples of the resected lymph nodes were systematically screened for the presence of disseminated tumor cells using immunohistochemistry (monoclonal antibody Ber-EP4). Clinical and histopathological parameters as well as the post-operative course were recorded. Survival data were analysed by the Kaplan-Meier method and the log rank test. Overall 321 lymph nodes of 40 patients were screened immunohistochemically. In 12.5% of the patients disseminated occult tumor cells were diagnosed. In addition to tumor resection 90% of the patients underwent adjuvant radio-iodine treatment. The mean observation period in our collective was 72 months. The detection of disseminated tumor cells did not correlate with clinicopathologic risk parameters and did not have significant influence on the prognosis of these patients. Immunohistochemical analysis enables the detection of disseminated tumor cells in patients with pN0 PTC. This finding seems to support the application of adjuvant radio iodine, even in early tumor stages.

High EpCAM expression is linked to proliferation and lauren classification in gastric cancer

BackgroundThe association of EpCAM expression with the progression of gastric cancer remains unclear. Here, we investigated the expression of EpCAM in gastric cancer subtypes and correlated the data to tumor cell proliferation and clinicopathologic factors.MethodsThe intratumoral expression of EpCAM was assessed in 163 primary gastric cancers (61 diffuse-, 62 intestinal-, 32 mixed-type and 8 unclassified tumors) by immunohistochemistry, using the monoclonal antibody Ber-EP4. Intensity of staining was classified according the HercepTest-score using a standardized scoring system. Ki-67 was used to examine the proliferation in tumor tissue.ResultsStrong EpCAM expression was observed in 77% of the tumors and in 85% of the corresponding lymph nodes. Of the primary tumors, 58% (n=74) presented a homogeneous intratumoral EpCAM expression while 42% were characterised by a heterogenous expression pattern. Tumors with high EpCAM expression at the invasive front were associated with significantly (p=0.03) higher proportion of lymph node metastases and lower median overall survival (p=0.001). Diffuse type tumors presented a significantly higher EpCAM expression at the invasion front compared with the tumor centre (p=0.036). Multivariate survival analysis identified high EpCAM expression at the invasive front as an independent prognostic factor.We observed a significant (p=0.001) correlation between high EpCAM expression and higher tumor cell proliferation.ConclusionHigh EpCAM expression associates with proliferation and progression of gastric cancer, especially in the diffuse type. Considering the discontenting results of the current adjuvant concepts for gastric cancer patients, EpCAM might be target in the adjuvant therapy of this malignant disease.

Prognostic Significance of EpCAM-Positive Disseminated Tumor Cells in Rectal Cancer Patients With Stage I Disease

Here we evaluated the prevalence and prognostic impact of epithelial cell adhesion molecule (EpCAM)-positive disseminated tumor cells (DTCs) in stage I rectal cancer. Further we tested the association of these single tumor cells or small tumor cell groups with the extent of peritumoral lymphangiogenesis. A total of 845 regional lymph nodes (LN) of 44 patients classified as negative on conventional histopathology were retrospectively reanalyzed with immunohistochemistry (IHC) using the monoclonal antibody Ber-Ep4 directed against EpCAM for the detection of DTCs. The degree of lymphangiogenesis in the primary tumors was assessed by IHC of the primary tumor tissue using the monoclonal antibody D2-40, which reacts with the lymphatic endothelium. The IHC results were correlated with clinico-pathologic parameters and clinical follow-up data. EpCAM-positive DTCs in LNs were detected in 8 (18.2%) of the 44 patients. During a median follow-up of 59 months, 3 (37.5%) of the 8 patients with EpCAM-positive DTCs relapsed, whereas none of the DTC-negative patients developed tumor recurrence (P=0.004). Survival analysis revealed a significant effect of the prevalence of DTCs on overall survival (P=0.0009) and on recurrence-free survival (P=0.0001). Finally, the prevalence of EpCAM-positive DTCs in perirectal LNs was significantly correlated with a high density of peritumoral lymphatic vessels (P=0.015). Our results show that DTCs may occur in stage I of rectal cancer and are associated with poor prognosis. Their occurrence seems to be linked to a high density of newly formed lymphatic vessel at the primary tumor site. According to our data, patients with DTCs in their LN might benefit from adjuvant therapy.

Increased EpCAM expression in malignant insulinoma: potential clinical implications

EpCAM (CD326) is overexpressed in progenitor cells of endocrine pancreatic islands of Langerhans during fetal development and was suggested to act as a morphoregulatory molecule in pancreatic island ontogeny. We tested whether EpCAM overexpression is reactivated in insulinomas, endocrine tumors arising in the pancreas. We used monoclonal anti-EpCAM antibody Ber-Ep4 for immunohistochemistry on formalin-fixed and paraffin-embedded tumor material. We analyzed 53 insulinomas: 40 benign (disease stage<IIa) and 13 malignant tumors (disease stage IIIb/IV). Disease stage disposition followed new TNM classification of the European Neuroendocrine Tumor Society (ENETS) for foregut neuroendocrine tumors (2006). Additionally, ten insulinoma metastases were analyzed. Clinical follow-up was available for overall survival analysis from 49 patients. The EpCAM expression of the islands of Langerhans was classified as 2+ in healthy pancreatic tissue. In 38% of the benign insulinomas (disease stage<IIa), we found strong (3+) EpCAM expression. In contrast, malignant insulinomas (disease stage IIIb/IV) and their metastases exhibited a strong (3+) EpCAM expression with 78 and 80% respectively, significantly more frequent (P<0.01). The malignant tissue was characterized by a significantly lower number of unstained cells and significantly higher number of 3+ stained cells. Quantitative PCR for EpCAM mRNA validated strong EpCAM expression in malignant insulinoma. Kaplan-Meier curves indicated survival disadvantage for EpCAM 3+ insulinomas, but this was not statistically significant (log-rank test). This first EpCAM expression study in benign/malignant insulinomas indicates that strong EpCAM expression could help to identify patients at risk for malignant disease and might be used as a therapeutic target for antibody-based therapies in patients with metastatic insulinoma.

An unusual ostensible example of intraoral basal cell carcinoma

An example of oral basal cell carcinoma is presented originating on the posterior mandibular mucosa and gingiva of a 67-year-old female. Histologically, it featured a multifocal pattern. It recurred eight times in a period of 20 years. Tissue samples of the tumor were evaluated with monoclonal antibody Ber-EP4 and were compared with examples of oral mucosa, skin, oral and cutaneous squamous cell carcinoma, peripheral ameloblastoma, ameloblastoma and cutaneous basal cell carcinoma (BCC). Only neoplastic basal cells showed positive immunohistochemical staining. Additionally, microdissected neoplastic areas were evaluated for loss of heterozygosity (LOH) of the PTCH gene with markers D9S303, D9S252 and D9S287. PTCH gene mutations are reported in patients with Gorlin syndrome and sporadic cutaneous BCCs. Loss of one allele was observed with all three markers. Examples of conventional ameloblastomas did not show evidence of LOH. These observations support the inclusion of BCC in the differential diagnosis of appropriate oral mucosal neoplasms.

Nodal Microinvolvement in Patients with Carcinoma of the Papilla of Vater Receiving No Adjuvant Chemotherapy

BackgroundTo assess the prognostic significance of nodal microinvolvement in patients with carcinoma of the papilla of Vater. MethodsFrom 1993 to 2003 at the University Clinic Hamburg, 777 patients were operated upon pancreatic and periampullary carcinomas. The vast majority of patients were operated upon pancreatic ductal adenocarcinoma (n = 566, 73%), followed by carcinomas of the papilla of Vater (n = 112, 14%), pancreatic neuroendocrine carcinomas (n = 39, 5%), intraductal papillary mucinous neoplasms (n = 33, 4%), and distal bile duct carcinomas (n = 27, 3%). Fresh-frozen tissue sections from 169 lymph nodes (LNs) classified as tumor free by routine histopathology from 57 patients with R0 resected carcinoma of the papilla of Vater who had been spared from adjuvant chemotherapy were immunohistochemically (IHC) examined, using a sensitive IHC assay with the anti-epithelial monoclonal antibody Ber-EP4 for tumor cell detection. With regard to histopathology, 39 (63%) of the patients were staged as pT1/pT2, 21 (37%) as pT3/pT4, 30 (53%) as pN0, while 38 (67%) as G1/G2. ResultsOf the 169 “tumor-free” LNs, 91 LNs (53.8%) contained Ber-EP4-positive tumor cells. These 91 LNs were from 40 (70%) patients. The mean overall survival in patients without nodal microinvolvement of 35.8 months (median—not yet reached) was significantly longer than that in patients with nodal microinvolvement (mean 16.6; median 13; p = 0.019). Multivariate Cox regression analysis for overall survival revealed that grading was the most significant independent prognostic factor (p = 0.001), followed by nodal microinvolvement (p = 0.013). ConclusionsThe influence of occult tumor cell dissemination in LNs of patients with histologically proven carcinoma of the papilla of Vater supports the need for further tumor staging through immunohistochemistry.

Occult disseminated tumor cells in lymph nodes of patients with gastric carcinoma. A critical appraisal of assessment and relevance

In gastric cancer, regional lymph node metastasis verified by histopathological examination is the most important prognostic factor after complete surgical tumor resection (R0). However, the prognostic value of immunohistochemically identifiable disseminated tumor cells in lymph nodes without histopathological tumor burden in patients with gastric cancer is still controversially discussed. The aim of the study was to assess the frequency and prognostic impact of minimal tumor cell spread to lymph nodes in these patients. One hundred sixty lymph nodes judged as "tumor free" on routine histopathology obtained from 58 patients with gastric adenocarcinoma were analyzed immunohistochemically using the monoclonal anti-EpCAM antibody Ber-EP4 for occult disseminated tumor cells. Tumor cells in lymph nodes were detected in 62 (38.8%) of the 160 "tumor-free" lymph nodes obtained from 39 (67.2%) patients. Multivariate Cox regression analysis confirmed the presence of disseminated tumor cells in "tumor-free" lymph nodes as an independent prognostic factor for both a significantly reduced relapse-free survival (p = 0.008) and overall survival (p = 0.009). The frequent occurrence and prognostic impact of minimal disseminated tumor cells in lymph nodes of patients with gastric carcinoma support the need for a refined staging system of excised lymph nodes, which should include immunohistochemical examination.

Ber‐EP4 enhances the differential diagnostic accuracy of cytokeratin 7 in pagetoid cutaneous neoplasms

While cytokeratin 7 is a reliable marker for most cases of Paget's disease, it is not 100% sensitive. Moreover, cases of cytokeratin 7-positive pagetoid squamous cell carcinoma in situ are reported in the literature. The monoclonal antibody Ber-EP4 is diagnostically highly reliable in the differentiation between basal cell carcinoma and cutaneous squamous cell carcinoma. Here we report its application in the differential diagnosis of cutaneous pagetoid neoplasms. Biopsy samples from 21 cases of extramammary Paget's disease, 12 pagetoid squamous cell carcinomas in situ and 10 pagetoid melanomas in situ of the superficial spreading type were examined immunohistochemically with Ber-EP4, 34betaE12 and HMB-45. Ber-EP4 selectively labeled all cases of extramammary Paget's disease but none of the other pagetoid neoplasms. The majority of cases (18 = 85.7%) displayed strong and three (14.3%) showed moderate immunoreactivity. Ber-EP4 reliably differentiates extramammary Paget's disease from pagetoid squamous cell carcinoma in situ and pagetoid melanoma in situ. The antibody should be included along with a panel of other markers when evaluating for pagetoid cutaneous neoplasms in order to avoid a possible misdiagnosis of pagetoid squamous cell carcinoma in situ.

L1 is associated with micrometastatic spread and poor outcome in colorectal cancer

L1 is a cell adhesion molecule expressed at the invasive front of colorectal tumors with an important role in metastasis. The aim of the present study was to determine L1 protein expression in a large cohort of colorectal cancer patients and its impact on early metastatic spread and survival. A total of 375 patients that underwent surgical treatment for colorectal cancer were chosen retrospectively. A tissue microarray was constructed of 576 tissue samples from these patients and analyzed by immunohistochemistry with a monoclonal antibody against human L1 (UJ127). Lymph node and bone marrow micrometastasis were assessed with monoclonal antibodies Ber-EP4 and pancytokeratin A45-B/B3, respectively. Associations between L1 expression and lymph node, bone marrow micrometastasis and survival were investigated with Fisher's, log-rank test and Cox multivariate analysis. All statistical tests were two-sided. L1 was detected in a subset of 48 (13%) of 375 patients examined. Analysis of L1 expression and survival revealed a significantly worse outcome for L1-positive patients by log-rank test (P<0.05). Multivariate Cox regression analysis showed the strongest independent prognostic impact of L1 expression (P<0.05). Fisher's test revealed a significant association of L1 expression and presence of disseminated tumor cells in lymph nodes and bone marrow (P<0.05). L1 is a powerful prognostic marker for patients that undergo complete surgical resection. It may have a role in early metastatic spread, as L1 is associated with micrometastases to both the lymph nodes and bone marrow. Thus, L1 should be explored further as a target for adjuvant therapy for micrometastatic disease.

Monoclonal antibody Ber‐EP4 reliably discriminates between microcystic adnexal carcinoma and basal cell carcinoma

Sclerosing cutaneous neoplasms often represent a diagnostic challenge. The monoclonal antibody Ber-EP4 recognizes two glycopolypeptides found in most human epithelial cells. It is diagnostically highly reliable in the differentiation between basal cell carcinoma and cutaneous squamous cell carcinoma. In this study, we report its application in the differential diagnosis of microcystic adnexal carcinoma, desmoplastic trichoepithelioma and basal cell carcinoma. Biopsy samples from 28 sclerosing and infiltrating basal cell carcinomas, 13 microcystic adnexal carcinomas and 16 desmoplastic trichoepitheliomas were examined after immunohistochemical staining with Ber-EP4. Ber-EP4 did not label any of the microcystic adnexal carcinomas, whereas all 28 basal cell carcinomas were Ber-EP4 positive. Twenty-seven of the 28 showed moderate or strong staining intensity, with the majority being strong. Only one basal cell carcinoma was weakly positive. Twelve of the 16 desmoplastic trichoepitheliomas were immunoreactive with Ber-EP4 and the staining was more variable than those of basal cell carcinomas. Ber-EP4 reliably differentiates microcystic adnexal carcinoma from basal cell carcinoma to the same extent as it distinguishes the latter tumor from squamous cell carcinoma. While it stains the majority of desmoplastic trichoepitheliomas, these tumors still have to be considered in the differential diagnosis with microcystic adnexal carcinoma, when Ber-EP4 is applied.

Morphological and immunohistochemical characterization of isolated tumor cells by p53 status in gastrointestinal tumors

Isolated tumor cells (ITCs) in cancer patients are retrieved mostly using immunohistochemistry with antibodies directed against antiepithelial antigens (for example Ber-EP4), which are supposed not to be present in metastatic-free tissue. To date, there has been ongoing controversy whether those cells have biologic significance and are linked with tumor progression and impaired patient's prognosis. Therefore, the aim of this study was to further characterize Ber-EP4-positive cells in various tissues, with special emphasis on their tumorigenic origin. The frequency and prognostic impact of ITCs in lymph nodes displayed by means of monoclonal antibody Ber-EP4 were evaluated in retrospective (n = 292) and prospective (n = 100) collectives of various gastrointestinal carcinomas free of metastatic disease in conventional histopathology (pN0). Furthermore, the frequency of ITCs in the peritoneal cavity and bone marrow was analyzed in case of absence of overt distant metastasis (pM0) in the prospective collective. Ber-EP4-immunoreactive cells were further characterized for tumorigenic origin using morphological criteria and immunohistochemical double staining for Ber-EP4 and p53. Ber-EP4-positive cells could be revealed in lymph nodes in 44.3% of pN0-gastrointestinal carcinomas, in the peritoneal cavity in 19%, and in the bone marrow in 10%. In lymph nodes, BerEP4-immunoreactive cells exhibited a metastatic-atypical morphology in 59%; however, it was always typical for true tumor cells in the peritoneal cavity or bone marrow. The cumulative 5-year survival rate was adversely affected by Ber-EP4-immunoreactive cells in uni- and multivariate analysis, irrespective of the underlying cell morphology (68% for Ber-EP4 negative, 41% for Ber-EP4 positive with atypical and typical morphology each). In the case of a p53-positive primary tumor, 70% of the corresponding ITCs also overexpressed p53, while the remainder was deemed p53 negative (p = 0.002). ITCs detected by the antiepithelial antibody Ber-EP4 are present in a substantial proportion of apparently tumor-free lymph nodes. These cells impair patients' prognoses, irrespective of the underlying cell morphology. As approximately one third of Ber-EP4-positive cells in p53-positive primary tumors do not overexpress p53; their true tumorigenic origin needs to be further investigated.

Frequency and prognostic significance of occult tumor cells in lymph nodes in patients with adenocarcinoma of the papilla of Vater

Background: Occurrence of tumor relapse is frequent in patients with carcinoma of the papilla of Vater despite the absence of residual tumor detectable at primary surgery. Therefore it has to be assumed that current tumor staging procedures fail to identify minimal amounts of tumor cells disseminated to secondary organs, which might be precursors of subsequent metastatic relapse. The aim of the study was to assess the frequency and prognostic impact of minimal tumor cell spread in lymph nodes classified as ‘tumor-free’ in routine histopathologic evaluation. Materials and methods: A total of 41 ‘tumor-free’ lymph nodes from 23 patients with adenocarcinoma of the papilla of Vater who underwent curative tumor resection (R0) were examined by immunohistochemistry with the monoclonal anti-EpCAM antibody Ber-EP4 for minimal disseminated tumor cells. Results: Twelve (29.3%) of the 41 ‘tumor-free’ lymph nodes obtained from 9 (39.1%) of the 23 patients displayed EpCAM-positive cells. Kaplan–Meier survival analysis revealed that patients with EpCAM-positive cells in lymph showed a clearly reduced relapse-free and overall survival compared with patients without such cells. However, these differences were not statistically significant (p= 0.13 for relapse-free survival, p= 0.11 for overall survival). Discussion: Immunohistochemical assessment may refine the staging of resected lymph nodes in patients with carcinoma of the papilla of Vater. However, the presence of minimal disseminated tumor cells in lymph nodes had no significant impact on the prognosis in these patients.

Loss of membranous Ep-CAM in budding colorectal carcinoma cells

AbstractTumor budding is a histological feature that reflects loss of adhesion of tumor cells and is associated with locoregional metastasis of colorectal carcinoma. Although nuclear localization of β-catenin is associated with tumor budding, the molecular mechanism remains largely elusive. In this study, we hypothesize that the epithelial cell adhesion molecule (Ep-CAM) is involved in tumor budding. In order to address this question, we performed immunohistochemistry on Ep-CAM using three different antibodies (monoclonal antibodies Ber-ep4 and 311-1K1 and a polyclonal antibody) and a double staining on β-catenin and Ep-CAM. In addition, Ep-CAM mRNA was monitored with mRNA in situ hybridization. Subsequently, we determined the effect of Ep-CAM staining patterns on tumor spread in rectal cancer. In contrast to the tumor mass, budding cells of colorectal carcinoma displayed lack of membranous but highly increased cytoplasmic Ep-CAM staining and nuclear translocation of β-catenin. mRNA in situ hybridization suggested no differences in Ep-CAM expression between the invasive front and the tumor mass. Importantly, reduced Ep-CAM staining at the invasive margin of rectal tumor specimens (n=133) correlated significantly with tumor budding, tumor grade and an increased risk of local recurrence (P=0.001, P=0.04 and P=0.03, respectively). These data demonstrate abnormal processing of Ep-CAM at the invasive margin of colorectal carcinomas. Our observations indicate that loss of membranous Ep-CAM is associated with nuclear β-catenin localization and suggest that this contributes to reduced cell–cell adhesions, increased migratory potential and tumor budding.

Ep-CAM expression in squamous cell carcinoma of the esophagus: a potential therapeutic target and prognostic marker

BackgroundTo evaluate the expression and test the clinical significance of the epithelial cellular adhesion molecule (Ep-CAM) in esophageal squamous cell carcinoma (SCC) to check the suitability of esophageal SCC patients for Ep-CAM directed targeted therapies.MethodsThe Ep-CAM expression was immunohistochemically investigated in 70 primary esophageal SCCs using the monoclonal antibody Ber-EP4. For the interpretation of the staining results, we used a standardized scoring system ranging from 0 to 3+. The survival analysis was calculated from 53 patients without distant metastasis, with R0 resection and at least 2 months of clinical follow-up.ResultsEp-CAM neo-expression was observed in 79% of the tumors with three expression levels, 1+ (26%), 2+ (11%) and 3+ (41%). Heterogeneous expression was observed at all expression levels. Interestingly, tumors with 3+ Ep-CAM expression conferred a significantly decreased median relapse-free survival period (log rank, p = 0.0001) and median overall survival (log rank, p = 0.0003). Multivariate survival analysis disclosed Ep-CAM 3+ expression as independent prognostic factor.ConclusionOur results suggest Ep-CAM as an attractive molecule for targeted therapy in esophageal SCC. Considering the discontenting results of the current adjuvant concepts for esophageal SCC patients, Ep-CAM might provide a promising target for an adjuvant immunotherapeutic intervention.

Tumor-Cell Homing to Lymph Nodes and Bone Marrow and CXCR4 Expression in Esophageal Cancer

The chemokine and bone marrow-homing receptor CXCR4 has been implicated in metastatic dissemination of various cancers. We investigated CXCR4 expression in esophageal cancer specimens and its association with survival, lymph node microinvolvement, and bone marrow micrometastasis. We analyzed frozen tumor specimens from 136 patients with completely resected esophageal cancer for CXCR4 expression by immunohistochemistry. Lymph node microinvolvement and bone marrow micrometastasis were assessed by immunohistochemistry with monoclonal antibodies Ber-EP4 (against epithelial cell adhesion molecule) and pancytokeratin A45-B/B3 (against several cytokeratins), respectively. Associations between CXCR4 expression and clinicopathologic features, including tumor stage, histologic grade, lymph node metastasis and microinvolvement, bone marrow micrometastasis, and survival, were investigated with Fisher's test, log-rank test, and Cox multivariable analysis. All statistical tests were two-sided. CXCR4 protein was expressed in 75 (55%) of 136 esophageal tumors examined. CXCR4 expression was statistically significantly associated with reduced median overall and disease-specific survival, compared with CXCR4 nonexpression (P < .001; log-rank test). The median overall survival of patients with CXCR4-positive tumors was 20 months and with CXCR4-negative tumors, 76 months (difference = 56 months, 95% confidence interval [CI] = 4 to 108 months; P < .001). The median disease-specific survival of patients with CXCR4-positive tumors was 25 months and with CXCR4-negative tumors was 97 months (difference = 72 months, 95% CI = 34 to 110 months; P < .001). CXCR4 expression was statistically significantly associated with increased lymph node microinvolvement (P < .001) and with increased bone marrow micrometastasis (P < .001). In multivariable analysis, CXCR4 expression, compared with its nonexpression, was identified as the independent variable that was most strongly associated with reduced disease-specific survival (relative risk [RR] of death = 2.03, 95% CI = 1.20 to 3.41; P = .008) and overall survival (RR of death = 2.18, 95% CI = 1.33 to 3.59; P = .002). CXCR4 expression was associated with poor clinical outcome in esophageal cancer patients. CXCR4 may have a role in early metastatic spread because its expression was associated with micrometastases to both the lymph nodes and bone marrow. Thus, CXCR4 should be explored further as a target for adjuvant therapy for micrometastatic disease.

Okkulte lymphatische Tumorzelldisseminierung beim Pankreaskarzinom

The aim of this study was to determine the frequency and effect on prognosis of occult tumor cells in regional lymph nodes judged to be tumor-free in conventional histopathology of pancreatic cancer patients. Among 115 patients who underwent pancreatic resection for pancreatic (n=84) or distal common bile duct malignancy (n=12) or carcinoma of the papilla (n=19), 48 (42%) were staged pN0. Archival paraffin blocks of 271 resected regional lymph nodes of 41 pN0 patients were reevaluated for occult tumor cells using monoclonal antibody Ber-EP4. Cases with or without isolated tumor cells were compared regarding the distribution of various clinicopathological factors. Of 41 pN0 patients, 16 (39%) exhibited single Ber-Ep4 immunoreactive cells or small cell clusters in at least one lymph node. The occurrence of occult tumor cells was not dependent on other clinicopathological factors such as pT stage, grading, or curative resection. However, those cells were encountered more frequently in common bile duct carcinomas (100%) than in pancreatic (36%) or papilla (20%) carcinomas (P=0.009). Occult tumor cells impaired prognosis significantly in uni- and multivariate analyses (estimated 5-year survival 53% for pN0((i-)) vs 10% for pN0((i+)) and 9% for pN1/N2; P=0.0047). Occult tumor cells are frequent in apparently tumor-free lymph nodes of pancreatic cancer patients and often overlooked in conventional histopathology. They are encountered even in limited stages of disease and they impair prognosis, which is comparable to that of patients with true lymphatic metastases. Occult tumor cells in lymph nodes of pancreatic cancer patients could be used to stratify adjuvant therapy.

Expression of epithelial-cell adhesion molecule (Ep-CAM) in small cell lung cancer as defined by monoclonal antibodies 17-1A and BerEP4

Small cell lung cancer (SCLC) comprises 15–20% of all lung cancer. Despite high initial response to chemotherapy chemoresistance at relapse leads to a less than 5% five-year survival rate. Adjuvant treatment with monoclonal antibodies (Mabs) against SCLC antigens may offer a therapeutic option. Mab 17-1A directed against the epithelial-cell adhesion molecule (Ep-CAM) has been extensively tested for therapy in patients with colorectal carcinoma. Expression of Ep-CAM in SCLC has been earlier described. However, reactivity of Mab 17-1A and another Ep-CAM-binding Mab BerEP4 has not yet been described for SCLC. Using immunohistology first with BerEP4 and confirmatory with 17-1A a homogenous and strong expression of Ep-CAM was seen in all SCLC specimens tested (n = 10). For comparison, heterogenous expression was seen in the non-SCLC tumors tested (n = 15). These findings strongly suggest that Mab 17-1A can be useful for adjuvant immunotherapy in patients with SCLC. For detection of Ep-CAM in tumor tissue in patients that might be considered for immunotherapy with Mab 17-1A, Mab BerEP4 appears to be preferred.

Mode of spread in the early phase of lymphatic metastasis in pancreatic ductal adenocarcinoma: prognostic significance of nodal microinvolvement.

The aim of this study was to assess the prognostic significance of nodal microinvolvement as well as the mode of spread in the early phase of lymphatic metastasis in patients with node-negative pancreatic ductal adenocarcinoma. Lymph nodes from 48 node-negative patients with R0 resected pancreatic ductal adenocarcinoma were sampled from 3 different compartments: 1) distal hepatoduodenal ligament, 2) superior-anterior compartment, and 3) posterior-inferior. Tissue sections of 148 lymph nodes classified as tumor free by routine histopathology were examined, using a sensitive immunohistochemical assay with the antiepithelial monoclonal antibody Ber-EP4 for tumor cell detection. With regard to histopathologic tumor staging and grading, 26 (54.2%) of the patients were staged as pT1/pT2, 22 (45.8%) as pT3/pT4, while 31 (64.6%) as G1/G2 and 17 (35.4%) patients as G3. Of the 148 "tumor free" lymph nodes, 56 contained Ber-EP4-positive tumor cells. These 56 lymph nodes were from 28 of the 48 patients. The multivariate Cox regression analysis revealed the independent prognostic impact of nodal microinvolvement on relapse-free and overall survival. Analysis by compartment, from which the lymph nodes were collected, revealed that overall survival time (P = 0.006) and time to local recurrence (P = 0.015) depend on the presence of nodal microinvolvement in the superior-anterior compartment. The influence of occult tumor cell dissemination in lymph nodes of patients with histologically proven pancreatic ductal adenocarcinoma supports the need for further tumor staging through immunohistochemistry. This could be a helpful tool in proper selection of patients for adjuvant chemotherapy.

Significance of isolated tumor cells in lymph nodes among gastric cancer patients.

To determine the frequency and prognostic impact of isolated tumor cells (ITC) in regional lymph nodes judged to be tumor free in conventional histopathology among gastric cancer patients. Among 161 patients who underwent gastrectomy and D2-lymphadenectomy, 56 were staged pN0(35%). Archival paraffin blocks of 1148 resected regional lymph nodes of those pN0 patients were reevaluated for ITC using monoclonal antibody Ber-EP4. Patients with and without ITC were compared with regard to the distribution of various clinicopathological factors. Prognostic impact of ITC was tested in uni- and multivariate analysis. Of 56 pN0 patients, 33 (59%) exhibited single Ber-Ep4 immunoreactive cells or small cell clusters in at least one lymph node. The occurrence of ITC was not dependent on other clinicopathological factors. ITC impaired patients' prognoses significantly in uni- as well as multivariate analyses [estimated 5-year survival rate: 82% for pN0((i-))vs 58% for pN0((i+))(p = 0.059) and 15% for pN1/2 (p = 0.0005 and p < 0.0001, respectively)]. ITC are a frequent event in apparently tumor-free lymph nodes of gastric cancer patients and are overlooked by conventional histopathology. They are encountered even in limited stages of disease and impair patients' prognoses. This should be borne in mind when advocating local resection for early gastric cancer.

Real-time reverse transcription-polymerase chain reaction assay for GA733-2 mRNA in the detection of metastatic carcinoma cells in serous effusions.

Cytomorphologic and immunocytologic examination alone provide only limited sensitivity for the detection of metastatic carcinoma cells in many cases of serous effusions. The specificity of conventional reverse transcription-polymerase chain reaction (RT-PCR) methods for detection of epithelial gene transcripts is low owing to the ectopic expression of many such genes in nonepithelial cells. For the detection of metastatic carcinoma cells, we describe a quantitative real-time RT-PCR assay for GA733-2 messenger RNA encoding an epithelial glycoprotein (EGP-2) that binds to the monoclonal antibody BerEP4. With serial dilutions of BerEP4-positive SK-BR-3 breast carcinoma cells, the RT-PCR assay was able to detect 10 carcinoma cells in a background of 10(6) lymphoid cells compared with 10(2) to 10(3) carcinoma cells detectable by immunocytologic examination. We analyzed 51 serous effusions, including 25 malignant metastatic effusions, by the real-time RT-PCR assay. Receiver operating characteristic curve analyses demonstrated a sensitivity of 96% corresponding to a specificity of 98% for a correct diagnosis of metastatic effusions. These results provide evidence that the GA733-2 real-time RT-PCR assay is a specific and sensitive tool for the detection of metastasis of BerEP4-positive primary tumors in serous effusion specimens.