The presence of a cytopathologist increases the diagnostic accuracy of endoscopic ultrasound-guided fine needle aspiration cytology for pancreatic adenocarcinoma: a meta-analysis.

OBJECTIVE: A meta-analysis has not been previously performed to evaluate critically the diagnostic accuracy of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) of solely pancreatic ductal adenocarcinoma and address factors that have an impact on variability of accuracy. The aim of this study was to determine whether the presence of a cytopathologist, variability of the reference standard and other sources of heterogeneity significantly impacts diagnostic accuracy. METHODS: We conducted a comprehensive search to identify studies, in which the pooled sensitivity, specificity, likelihood ratios for a positive or negative test (LR+, LR-) and summary receiver-operating curves (SROC) could be determined for EUS-FNA of the pancreas for ductal adenocarcinoma using clinical follow-up, and/or surgical biopsy or excision as the reference standard. RESULTS: We included 34 distinct studies (3644 patients) in which EUS-FNA for a solid pancreatic mass was evaluated. The pooled sensitivity and specificity for EUS-FNA for pancreatic ductal adenocarcinoma was 88.6% [95% confidence interval (CI): 87.2-89.9] and 99.3% (95% CI: 98.7-99.7), respectively. The LR+ and LR- were 33.46 (95% CI: 20.76-53.91) and 0.11 (95% CI: 0.08-0.16), respectively. The meta-regression model showed rapid on-site evaluation (ROSE) (P = 0.001) remained a significant determinant of EUS-FNA accuracy after correcting for study population number and reference standard. CONCLUSION: EUS-FNA is an effective modality for diagnosing pancreatic ductal adencarcinoma in solid pancreatic lesions, with an increased diagnostic accuracy when using on-site cytopathology evaluation.

Targeting ErbB3-mediated stromal-epithelial interactions in pancreatic ductal adenocarcinoma.

BACKGROUND: We sought to investigate the role of ErbB3-mediated signalling on the interaction between pancreatic cancer-associated fibroblasts (CAF) and carcinoma cells in an effort to disrupt tumourigenic pancreatic ductal adenocarcinoma (PDAC) stromal-epithelial cross-communication. METHODS: Primary CAF cultures were established from human PDAC surgical specimens. AsPC-1 pancreatic cancer cell murine subcutaneous xenografts were developed in the presence and absence of CAF and were subsequently treated with epidermal growth factor receptor (EGFR) inhibitors (erlotinib) and ErbB3 inhibitors (MM-121, monoclonal ErbB3 antibody). RESULTS: Cancer-associated fibroblasts were found to secrete neuregulin-1 (NRG-1), which promoted proliferation via phosphorylation of ErbB3 and AKT in AsPC-1 PDAC cells. This signalling cascade was effectively inhibited both in vitro and in vivo by specific ErbB3 blockade with MM-121, with greater degree of tumourigenesis inhibition when combined with erlotinib. The CAF-AsPC-1 pancreatic cancer xenografts reached significantly greater tumour volume than those xenografts lacking CAF and were resistant to the anti-tumour effects of EGFR inhibition with erlotinib. CONCLUSION: Cancer-associated fibroblasts-derived NRG-1 promote PDAC tumourigenesis via ErbB3-AKT signalling and overcomes single-agent EGFR inhibition. Disruption of this stromally mediated tumourigenic mechanism is best obtained through combined EGFR-ErbB3 inhibition with both erlotinib and MM-121. We have identified the NRG-1/ErbB3 axis as an attractive molecular target for the interruption of tumourigenic stromal-epithelial interactions within the PDAC microenvironment.

Immunohistochemical detection of EGFR, p185(erbB-2), Bcl-2 and p53 in breast carcinomas in pre-menopausal and post-menopausal women.

Young pre-menopausal women with breast carcinomas have an overall worse prognosis than older, post-menopausal women. Because histologic grade is a major predictor of tumor behavior and correlates with biomarker expression, we assessed the immunohistochemical expression of epidermal growth factor receptor (EGFR), p185(erbB-2) and Bcl-2, and nuclear accumulation of p53 in breast carcinomas in pre- and post-menopausal women with equivalent histologic grades. This allowed identification of differences in biomarker expression and prognostic significance in pre- and post-menopausal women independent of histologic grade. We investigated 100 infiltrating ductal carcinomas (IDC) in pre-menopausal women, ages 45 years and younger, and 100 IDC in post-menopausal women, ages 65 years and older. The IDC were selected so that the proportions of high and low/moderate grade carcinomas were equal in the pre- and post-menopausal groups. Prognostic utility of biomarker expression in pre- and post-menopausal groups was determined by product limit and multivariate analysis of survival. There were statistically significant differences in cytoplasmic expression of EGFR and Bcl-2 and nuclear accumulation of p53, but not in the expression of p185(erbB-2), in carcinomas of high vs. low histologic grade. There was no difference in the expression of EGFR, p185(erbB-2) or Bcl-2, or in nuclear accumulation of p53 in these IDC from pre- vs. post-menopausal women. Bcl-2 and the nuclear accumulation of p53 were of prognostic significance in our overall study population; however, when assessing pre- and post-menopausal women separately, Bcl-2 and p53 were of prognostic significance only in pre-menopausal, but not post-menopausal women. In summary expression of EGFR and Bcl-2 and nuclear accumulation of p53 were significantly associated with histologic grade, but not with menopausal status. In addition, there were differences in the prognostic effectiveness of these biomarkers in pre- vs. post-menopausal women.

An engineering approach to modelling, decision support and control for sustainable systems.

Engineering research and development contributes to the advance of sustainable agriculture both through innovative methods to manage and control processes, and through quantitative understanding of the operation of practical agricultural systems using decision models. This paper describes how an engineering approach, drawing on mathematical models of systems and processes, contributes new methods that support decision making at all levels from strategy and planning to tactics and real-time control. The ability to describe the system or process by a simple and robust mathematical model is critical, and the outputs range from guidance to policy makers on strategic decisions relating to land use, through intelligent decision support to farmers and on to real-time engineering control of specific processes. Precision in decision making leads to decreased use of inputs, less environmental emissions and enhanced profitability-all essential to sustainable systems.

Human cytosolic sulfotransferase 2B1: isoform expression, tissue specificity and subcellular localization.

Sulfation is an important Phase II conjugation reaction involved in the synthesis and metabolism of steroids in humans. Two different isoforms (2B1a and 2B1b) are encoded by the sulfotransferase (SULT) 2B1 gene utilizing different start sites of transcription resulting in the incorporation of different first exons. SULT2B1a and SULT2B1b are 350 and 365 amino acids in length, respectively, and the last 342 aa are identical. Message for both SULT2B1 isoforms is present in human tissues although SULT2B1b message is generally more abundant. However, to date only SULT2B1b protein has been detected in human tissues or cell lines. SULT2B1b is localized in the cytosol and/or nuclei of human cells. A unique 3'-extension of SULT2B1b is required for nuclear localization in human BeWo placental choriocarcinoma cells. Nuclear localization is stimulated by forskolin treatment in BeWo cells and serine phosphorylation has been identified in the 3'-extension. SULT2B1b is selective for the sulfation of 3beta-hydroxysteroids such as dehydroepiandrosterone and pregnenolone, and may also have a role in cholesterol sulfation in human skin. The substrate specificity, nuclear localization, and tissue localization of SULT2B1b suggest a role in regulating the responsiveness of cells to adrenal androgens via their direct inactivation or by preventing their conversion to more potent androgens and estrogens.

Intratumor heterogeneity of biomarker expression in breast carcinomas.

Small biopsy samples are used increasingly to assess the biomarker expression for prognostic information and for monitoring therapeutic responses prior to and during neoadjuvant therapy. The issue of intratumor heterogeneity of expression of biomarkers, however, has raised questions about the validity of the assessment of biomarker expression based on limited tissue samples. We examined immunohistochemically the expression of HER-2neu (p185erbB-2), epidermal growth factor receptor (EGFR), Bcl-2, p53, and proliferating cell nuclear antigen (PCNA) in 30 breast carcinomas using archived, paraffin embedded tissue and determined the extent of intratumor heterogeneity. Each section was divided into four randomly oriented discrete regions, each containing a portion of the infiltrating carcinoma. For each tumor, the entire lesion and four regions were analyzed for the expression of these markers. Scores of both membrane and cytoplasmic staining of HER-2neu and EGFR, scores of cytoplasmic staining of Bcl-2, and scores of nuclear staining of both p53 and PCNA were recorded. The intensity of staining and the proportion of immunostained cells were determined. A semiquantitative immunoscore was calculated by determining the sum of the products of the intensity and corresponding proportion of stained tumor cells. We analyzed both invasive (IDC) and in situ (DCIS) carcinomas. The Wilcoxon signed-rank test was used for paired comparisons between overall and regional immunoscores and between overall and regional percentages of stained cells. Spearman's correlation coefficients were used to assess the level of agreement of overall biomarker expression with each of the regions. Generalized linear models were used to assess overall and pair-wise differences in the absolute values of percent changes between overall and regional expression of biomarkers. For IDCs, there were no statistically significant differences in the expression of the biomarkers in terms of either the percentage of cells staining or the immunoscores when comparing the entire tumor with each region except for the lower EGFR expression of arbitrarily selected region 1 and lower p53 expression of region 1 compared to that of the entire tumor section. For DCIS, there were no statistically significant differences in the expression of the biomarkers between the entire tumor and each region except in PCNA of region 2 compared to that of entire tumor section. Positive correlation of immunoscores was observed between the entire tumor and each region as well as across all four regions for IDC. Similar observations were noted with DCIS except for HER-2neu and PCNA. No statistically significant differences were observed in the absolute values of percent changes of biomarker expression between overall and the four regions for both DCIS and IDC. Therefore, no significant intratumor heterogeneity in the expression of HER-2neu, Bcl-2, and PCNA was observed in IDC. Minor regional variations were observed for EGFR and p53 in IDC. Similarly, no significant regional variation in the expression of markers was observed in DCIS except for PCNA.

Race- and age-dependent alterations in global methylation of DNA in squamous cell carcinoma of the lung (United States).

OBJECTIVE: The current study investigated the race- and age-dependent alterations in global DNA methylation on the development and progression of squamous cell carcinomas (SCCs) of the lung. METHODS: Methylation status was evaluated in SCC and in the associated uninvolved bronchial mucosa (UBM) and epithelial hyperplasia (EH) of 53 Whites and 23 African Americans by using an antibody specific for 5-methylcytosine (5-mc). A low 5-mc score indicates global hypomethylation of DNA. RESULTS: 5-mc scores of SCC were significantly lower compared to 5-mc scores of UBM and EH in Whites (p < 0.05). In African Americans, 5-mc scores of SCCs were not significantly different from 5-mc scores of UBM and EH, suggesting an involvement of methylation in the development of SCCs in Whites, but not in African Americans. 5-mc scores were lower in younger subjects compared to older subjects in Whites. Since cancers in younger subjects tend to be more aggressive than cancers in older subjects, these observations may suggest that hypomethylation may have contributed to aggressiveness cancers of younger Whites. Hypomethylation of SCCs in White men was associated with shorter survival from the disease. CONCLUSIONS: These preliminary results suggest that the methylation status of DNA may affect the development, aggressiveness, and prognosis of SCCs in Whites.

Altered subcellular localization of suppressin, a novel inhibitor of cell-cycle entry, is an independent prognostic factor in colorectal adenocarcinomas.

PURPOSE: Suppressin (SPN), a novel inhibitor of the entry into the cell cycle, has properties of a tumor suppressor gene; however, its role in the development and progression of a human malignancy is not studied. Therefore, we evaluated the status of spn and its prognostic value in human colorectal adenocarcinoma (CRC). EXPERIMENTAL DESIGN: Inhibition of cell proliferation by exogenous/extracellular SPN was assessed by [(3)H]thymidine incorporation. The genetic status of spn in two colon cancer cell lines (LS180 and WiDr) and in a human CRC was determined using direct cDNA sequencing techniques. Phenotypic expression of SPN was evaluated in 105 CRC archival tissues using immunohistochemical methods. Univariate Kaplan-Meier and multivariate Cox proportional hazards models were used to determine the prognostic significance of SPN expression. RESULTS: Exogenous SPN inhibited the proliferation of the LS180 cell line, which also has a mutation in one allele of the spn gene. The spn gene was also mutated in the primary CRC. Expression of SPN was primarily cytoplasmic in nonmucinous CRCs and nuclear in mucinous CRCs. However, the evaluation of 85 nonmucinous CRCs demonstrated that nuclear localization of SPN, nuclear accumulation of p53, and nodal status were independent prognostic indicators with hazard ratios of 2.34, 2.33, and 3.04, respectively. Nuclear localization of SPN plus nuclear accumulation of p53 formed a stronger prognostic indicator (hazard ratios = 5.45) than local nodal status. CONCLUSIONS: This is the first report of genetic alterations in the spn gene in a human malignancy and suggests that genetic alterations in spn and the resulting immunohistochemical phenotypes based on SPN subcellular localization in CRCs may be useful in determining prognosis of patients with subtypes of CRC.

Altered global methylation of DNA: an epigenetic difference in susceptibility for lung cancer is associated with its progression.

Alterations in global DNA methylation have been observed in many cancers, but whether such alterations represent an epigenetic difference in susceptibility for the disease is unknown. The status of global DNA methylation also has not been reported in intact or specific types of cells involved in the carcinogenic process. To address these issues in lung carcinogenesis, we evaluated the status of global DNA methylation by using a monoclonal antibody specific for 5-methylcytosine (5-mc) in randomly selected lung specimens of 60 cigarette smokers who developed squamous cell carcinoma (SCC) and 30 cigarette smokers who did not. 5-mc immunostaining scores of DNA of SCC (0.61 +/- 0.42) and associated hyperplastic lesions (0.82 +/- 0.27) was significantly lower than those of DNA of histologically normal bronchial epithelial cells (0.99 +/- 0.52) and hyperplastic lesions (1.2 +/- 0.22) of noncancer specimens. The ratio of 5-mc scores between SCC and matched uninvolved bronchial epithelial cells was significantly associated with advanced stage and size of the tumor. The results suggest that alteration in global DNA methylation is an important epigenetic difference in susceptibility for the development of lung cancer. The reduced global DNA methylation in SCC compared with epithelial hyperplasia and its association with tumor size and disease stage is suggestive of its involvement in the progression of SCC. The results also indicate that normal methylation of DNA in epithelial hyperplastic lesions may prevent the transformation of these lesions to invasive cancer. If these results are confirmed, the status of DNA methylation in early lesions such as epithelial hyperplasia could be used to identify smokers who are at risk for the development of SCC.

Thyroid aspiration cytology: a "cell pattern" approach to interpretation.

The key to the interpretation of thyroid fine needle aspiration is largely dependent on the recognition of various morphologic patterns of epithelial cells, usually follicular cells, and background elements, such as colloid. These morphologic patterns consist of 3 parts: 1) The arrangement of cells with respect to one another, 2) The cytologic features of individual cells, and 3) The presence of background elements. The cellular arrangements generally encountered in fine needle aspiration of the thyroid include the follicular patterns (macro-/normo-follicular and micro-follicular), the papillary pattern, the syncytial pattern, the dispersed cell pattern, and the cystic pattern. This article approaches some of the differential diagnostic challenges encountered while interpreting thyroid aspiration cytology by focusing first on the overall cellular arrangement to generate a differential diagnosis and then narrowing that differential by assessing cellular features of individual cells and the presence of background elements.

Expression of human endogenous retrovirus k envelope transcripts in human breast cancer.

PURPOSE: We investigated the expression of human endogenous retroviral (HERV) sequences in breast cancer. EXPERIMENTAL DESIGN: Reverse transcription-PCR (RT-PCR) was used to examine expression of the envelope (env) region of ERV3, HERV-E4-1, and HERV-K in breast cancer cell lines, human breast tumor samples, adjacent uninvolved breast tissues, nonmalignant breast tissues, and placenta. Expression of HERV transcripts was confirmed by Northern blot analysis and in situ hybridization (ISH). To evaluate coding potential, amplified HERV sequences were cloned into vectors for expression and sequence analysis. RESULTS: No expression of ERV3 or HERV-E4-1 RNA was detected in the analyzed breast samples. In contrast, HERV-K transcripts were detected in most breast cancer cell lines and many breast tumor tissues. Expression was detected in a small percentage of matched, uninvolved breast tissues and in placentas but not nonmalignant breast tissues. In HERV-K-positive breast cancer tissues, Northern blot analysis demonstrated full-length proviral and spliced env transcripts. ISH demonstrated expression of HERV-K transcripts in breast tumor cells but not in normal or uninvolved breast epithelial cells. Independently isolated clones of HERV-K env cDNA generated recombinant proteins of the expected size. Sequence analysis of env cDNA clones derived from four breast tumor samples revealed >97% identity with the type I HERV-K102, with no premature termination codons. Independent isolates from the same breast tumor sample showed nucleotide sequence differences, suggesting that multiple loci may be transcribed. CONCLUSIONS: These data indicate that HERV-K transcripts with coding potential for the envelope region are expressed frequently in human breast cancer.

The spectrum of cytologic features in nonproliferative breast lesions.

BACKGROUND: The reliability of cytologic criteria to classify nonproliferative breast lesions (NPBL) is still debated. Sampling error and heterogeneity of breast lesions complicates the histologic correlation of fine-needle aspiration results further. METHODS: To provide optimal cytohistologic correlation, two smears (one that was stained with hematoxylin and eosin and one that was stained with Diff-Quik [American Scientific Products, McGraw Park, IL]) were prepared from specific tissue sections from breast biopsies without mass lesions. The 42 cases classified as NPBL histologically were included in the current study. The cytologic features of the smears were evaluated. RESULTS: Cellularity ranged from low (40% of cases) to moderate (50% of cases) to high (7% of cases). The cells were arranged in small clusters in 79% of cases, were mixed with large sheets in 17% of cases, and were in large sheets in 2% of cases. Intact lobules were noted in 31%. The configuration of the epithelial groups was complex in 62% of cases. Myoepithelial cells in the background and within the epithelial groups were noted in all the specimens. The percentage of single epithelial cells was < 10 in 38% of cases, 10-20 in 41%, and 20-30 in 19%. Mild nuclear enlargement and overlap, micronucleoli, and mild chromatin clumping were noted in a significant number of cases. CONCLUSIONS: NPBL have been found to have a wide spectrum of cytologic appearances. At one end of the spectrum, smears are cellular with up to 30% single cells and large sheets in a complex configuration and exhibit nuclear enlargement and overlap and prominent nucleoli, features that overlap with those described in proliferative breast lesions.

Fatty acid synthase: an early molecular marker of progression of prostatic adenocarcinoma to androgen independence.

PURPOSE: Changes in fatty acid synthase levels were investigated in the CWR22 xenograft model of prostatic adenocarcinoma after castration and during progression to androgen independence. MATERIALS AND METHODS: Male nude mice with CWR22 tumors were castrated and sacrificed 3, 7, 21, 28 or 42 days after castration. Some mice received testosterone replenishment 21 days after castration and were sacrificed 7 days later. In addition, other castrates were maintained for 7 to 10 months to allow tumors to relapse to androgen independence. Fatty acid synthase was measured by immunohistochemical study and Western blot analysis. RESULTS: Fatty acid synthase decreased rapidly after castration and after 28 to 42 days it was 5% to 10% of the level in tumors of intact controls. Temporal changes in fatty acid synthase after castration were associated with decreased proliferative potential and increased levels of the cyclin dependent kinase inhibitor p27Kip-1. Testosterone treatment of castrates at 21 to 28 days after castration increased fatty acid synthase expression to the level in tumors of intact controls. Tumors of long-term castrates with post-castration androgen independent growth had increased fatty acid synthase, as did small focal areas of androgen independent proliferation in tumors that had not increased in size by 7 to 10 months. In relapsed CWR22 tumors and in focal areas of androgen independent proliferation in nonrelapsed CWR22 tumors increased fatty acid synthase was associated spatially with increased proliferation and decreased p27Kip-1. CONCLUSIONS: Fatty acid synthase in CWR22 tumors depends initially on testosterone and it is associated with androgen mediated proliferation. Furthermore, increased fatty acid synthase levels associated with androgen independent proliferation may represent an early event in the development of the androgen independent phenotype.

Laser capture microdissection.

Laser capture microdissection (LCM) offers a rapid and precise method of isolating and removing specified cells from complex tissues for subsequent analysis of their RNA, DNA, or protein content, thereby allowing assessment of the role of the cell type in the normal physiologic or disease process being studied. In this unit, protocols for the preparation of mammalian frozen tissues, fixed tissues, and cytologic specimens for LCM, including hematoxylin and eosin staining, are presented, as well as a protocol for the performance of LCM utilizing the PixCell I or II Laser Capture Microdissection System manufactured by Arcturus Engineering. Also provided is a protocol for tissue processing and paraffin embedding, and recipes for lysis buffers for the recovery of nucleic acids and proteins. The Commentary section addresses the types of specimens that can be utilized for LCM and approaches to staining of specimens for cell visualization. Emphasis is placed on the preparation of tissue or cytologic specimens as this is critical to effective LCM.

Immunohistochemical evaluation of global DNA methylation: comparison with in vitro radiolabeled methyl incorporation assay.

The in vitro radiolabeled methyl incorporation assay, a commonly used technique to evaluate global methylation of DNA, has some disadvantages and limitations. The purpose of the present study was to compare the results of global DNA methylation evaluated by radiolabeled methyl incorporation (CPM/microg of DNA) with immunohistochemical staining of the same tissue sections with a monoclonal antibody developed against 5-methylcytosine used (5-mc). We archival specimens of squamous cell cancer (SCC) of the human lung with a matched uninvolved specimen (n = 18 pairs) and 18 lung specimens from subjects without lung cancer (noncancer specimens) to make this comparison. The immunostaining for 5-mc was reported as a percentage of cells positive for staining as well as a weighted average of the intensity score. The results suggested that both radiolabeled methyl incorporation assay and immunostaining for 5-mc can be used to demonstrate hypomethylation of DNA in SCC tissues compared to matched uninvolved tissues. An advantage of immunostaining, however, is its ability to demonstrate hypomethylation of SCC compared to adjacent bronchial mucosa on the same archival specimen, obviating the need to use sections from both SCC and matched uninvolved tissues. Only by using the immunostaining technique were we able to document a statistically significant difference in DNA methylation between SCC and noncancer tissues. We conclude that the immunostaining technique has advantages over the radiolabeled methyl incorporation assay and may be best suited for evaluation of global DNA methylation when the methylation status of cancer cannot be normalized by methyl incorporation of normal tissues or when the number of samples available for evaluation is small.

Increase of GKLF messenger RNA and protein expression during progression of breast cancer.

Genetic alterations found in carcinomas can alter specific regulatory pathways and provide a selective growth advantage by activation of transforming oncogenes. A subset of these genes, including wild-type alleles of GLI or c-MYC, and activated alleles of RAS or beta-catenin, exhibit transforming activity when expressed in diploid epithelial RK3E cells in vitro. By in vitro transformation of these cells, the zinc finger protein GKLF/KLF-4 was recently identified as a novel oncogene. Although GKLF is normally expressed in superficial, differentiating epithelial cells of the skin, oral mucosa, and gut, expression is consistently up-regulated in dysplastic epithelium and in squamous cell carcinoma of the oral cavity. In the current study, we used in situ hybridization, Northern blot analysis, and immunohistochemistry to detect GKLF at various stages of tumor progression in the breast, prostate, and colon. Overall, expression of GKLF mRNA was detected by in situ hybridization in 21 of 31 cases (68%) of carcinoma of the breast. Low-level expression of GKLF mRNA was observed in morphologically normal (uninvolved) breast epithelium adjacent to tumor cells. Increased expression was observed in neoplastic cells compared with adjacent uninvolved epithelium for 14 of 19 cases examined (74%). Ductal carcinoma in situ exhibited similar expression as invasive carcinoma, suggesting that GKLF is activated prior to invasion through the basement membrane. Expression as determined by Northern blot was increased in most breast tumor cell lines and in immortalized human mammary epithelial cells when these were compared with finite-life span human mammary epithelial cells. Alteration of GKLF expression was confirmed by the use of a novel monoclonal antibody that detected the protein in normal and neoplastic tissues in a distribution consistent with localization of the mRNA. In contrast to most breast tumors, expression of GKLF in tumor cells of colorectal or prostatic carcinomas was reduced or unaltered compared with normal epithelium. The results demonstrate that GKLF expression in epithelial compartments is altered in a tissue-type specific fashion during tumor progression, and suggest that increased expression of GKLF mRNA and protein may contribute to the malignant phenotype of breast tumors.

The expression of fatty acid synthase (FASE) is an early event in the development and progression of squamous cell carcinoma of the lung.

Correlation of elevated levels of the lipogenic enzyme, fatty acid synthase (FASE), with advanced stages of some cancers has drawn attention to this enzyme as a possible marker of poor prognosis. Because recent studies have shown that cancer cells are dependent on fatty acid synthetic activity and pharmacologic inhibitors of this enzyme are selectively cytotoxic to cancer cells, expression of FASE also may provide a potential target for intervention in the neoplastic process. To determine the potential usefulness of expression of FASE in the neoplastic process of the lung, we evaluated its pattern of expression immunohistochemically in archival specimens from 60 human lung specimens with squamous cell cancer (SCC) and associated "preneoplastic" lesions compared with its expression in the normal bronchial epithelium of 60 noncancer specimens. The expression of FASE was significantly higher in SCC associated uninvolved bronchial epithelium (mean = 0.40+/-0.03, median = 0.38) compared with its expression in the bronchial epithelium of noncancer specimens (mean = 0.18+/-0.02, median = 0.16) indicating its early expression. We also observed a statistically significant step-wise increase in FASE expression from SCC associated uninvolved bronchial epithelium (mean = 0.40+/-0.03, median = 0.38) to epithelial hyperplasia (0.58+/-0.04, median = 0.57) to SCC (1.53+/-0.06, median = 1.50). The results suggested that expression of FASE is an early event in the development and progression of SCC of the lung. The inhibition of fatty acid synthesis by inhibiting enzymatic function with metabolic analogues may be a useful strategy in the treatment of SCCs. The expression of FASE in early lesions such as SCC associated uninvolved bronchial epithelium and epithelial hyperplasia might also provide a potential means for intervention early in the neoplastic process in the lung or even preventing their malignant transformation to invasive carcinomas.

Methods of antigen recovery vary in their usefulness in unmasking specific antigens in immunohistochemistry.

Microwave heating of histologic sections in citrate buffer (MAR) is a widely used method of antigen recovery but often results in loss of tissue sections. Low-temperature antigen retrieval (LTAR), incubation at 80 degrees C in citrate buffer for 2 hours with trypsin pretreatment is an alternative method reported to result in better antigen recovery for specific antigens as well as decreased loss of tissue sections. To optimize our immunohistochemical evaluation of breast carcinomas, we compared the efficacy of these methods of antigen recovery for several important antigens. Ten breast carcinomas were immunostained for estrogen and progesterone receptors (ER and PR), Ki-67/ MIB 1, p27/Kip-1, and Bcl-2 after MAR, LTAR with enzymatic pretreatment, or no antigen recovery. The immunohistochemical staining was scored and compared for each antibody and antigen recovery combination. The proportion of tissue lost from each slide after staining also was assessed. More and stronger positive staining was achieved with antibodies to Ki67/MIB 1 and ER when LTAR was used compared with the other two methods; in contrast, optimal staining with antibodies to Bcl-2 was achieved when MAR was used. Staining with anti-p27/Kip- was nearly equal with either LTAR or MAR. Staining with anti-PR was slightly better with MAR than with LTAR. Tissue loss was greatest for MAR compared with LTAR or with no antigen recovery. For selected cases, LTAR caused focal tissue damage, and either the immunostaining with LTAR had to be repeated or only a portion of some tissue sections would be used for examination. LTAR was the most effective for ER and Ki-67/MIB 1. MAR provided the most intense staining for Bcl-2 and PR, but this enhanced staining must be weighed against the greater tissue section loss from MAR. This study demonstrated that AR methods are not equally applicable to all antibodies.

The expression of Ep-CAM (17-1A) in squamous cell cancers of the lung.

Immunotherapy trials using monoclonal antibodies 323/A3 and 17-1A that recognize Ep-CAM, including trials focused on cancer of the lung, currently are underway. Nevertheless, there have been few comprehensive evaluations of the expression of Ep-CAM in specific types of neoplastic processes, including cancer of the lung. The current study of 60 human subjects with squamous cell cancer (SCC) of the lung, selected at random, was undertaken (1) to examine the expression of Ep-CAM in SCC and associated uninvolved bronchial mucosa, bronchial epithelial hyperplasia, and dysplasia, and (2) to correlate the results with established prognostic indicators and survival of patients. In both the uninvolved bronchial mucosa and epithelial hyperplasia, the expression of Ep-CAM in luminal cells was significantly higher compared with its expression in the matched basal cells (P = .003, P < .0001, respectively). When Ep-CAM scores of basal and luminal cells present in uninvolved bronchial mucosa and epithelial hyperplasia were combined, we observed a statistically significant stepwise increase in Ep-CAM expression from uninvolved bronchial mucosa to epithelial hyperplasia to SCC, suggesting its involvement in malignant transformation of SCC. The expression of Ep-CAM was significantly higher in poorly to moderately differentiated SCC compared with well-differentiated SCC (P = .04). An increase in the expression of Ep-CAM with increasing size or local extent of the primary tumor approached statistical significance (P = .09). The expression of Ep-CAM increased significantly with increasing involvement of regional lymph nodes (P = .02). Similarly, the expression of Ep-CAM increased with the increasing TNM stages (P = .04). Kaplan-Meier Survival analysis using the same categorizations showed that increasing tumor size, nodal status, and stage were significantly associated with poor patient survival (P = .04, .01, .01, respectively). There was, however, no statistically significant association between patient survival and staining intensity of carcinomas for Ep-CAM. We conclude that expression of Ep-CAM increased during the progression of SCC of the lung and, therefore, may play a role in the carcinogenesis of this disease.