Expression of p53, pRB, and p16 in lung tumours: a validation study on tissue microarrays

Pan-TRK Immunohistochemistry and NTRK Gene Fusions in Primary Carcinomas of the Liver

Gene fusions involving NTRK are not common in solid tumors. The aim of this study was to investigate the TRK protein expression and molecular characteristics of gene fusions in primary liver carcinomas. A total of 110 hepatocellular carcinomas (HCC) and 69 intrahepatic cholangiocarcinomas were retrieved for tissue microarray (TMA) construction and clinicopathologic characterization. Immunohistochemistry (IHC) for pan-TRK was initially performed on TMA slides and evaluated for staining intensity. Twelve (10.9%) of 110 HCC showed weak cytoplasmic TRK expression by IHC on TMA, while all others, including 69 intrahepatic cholangiocarcinomas, were negative for TRK. The TRK expression did not correlate with patient's age, sex, tumor differentiation, or tumor stage. The 12 cases were then validated by IHC on whole sections but all turned out to be negative. Further, RNA sequencing analysis did not detect any NTRK fusions in all 12 HCC cases; however, it did identify many fusions frequently involving genes that encode mitochondrial and ribosomal proteins, microRNAs, and some transcription factors. A few fusions were recurrent, including MT-ATP6/MT-ATP8 fusion (n=9, 75%), Ig κ light chain gene IGKV/IGKJ fusion (n=5, 41.7%), and histocompatibility complex gene HLA-C/HLA-B fusion (n=4, 33.3%). In summary, NTRK fusion is very rare in primary liver carcinomas. IHC on TMA for TRK expression yields high false positive results, which should be validated on whole sections and confirmed by molecular genetic studies such as RNA sequencing. Many fusions involving genes other than NTRK are detected in HCC, the significance of which warrants further studies.

Significance of Triple Detection of p16/ki-67 Dual-Staining, Liquid-Based Cytology and HR HPV Testing in Screening of Cervical Cancer: A Retrospective Study

In addition to liquid-based cytology (LBC) and HR HPV testing, p16/ki-67 dual-staining is another method for cervical cancer screening. The combination of any two methods can improve the accuracy of screening, but some cervical lesions are still missed or misdiagnosed. In this retrospective study, the significance of LBC, HR HPV testing and especially p16/ki-67 dual-staining in cervical lesion screening was evaluated with reference to histological diagnosis. At the same time, we tried to explore the value of p16/ki-67 dual-staining combined with LBC and HR HPV testing (triple detection) in improving the diagnostic specificity of CIN2+ and reducing the missed diagnosis of CIN2+ lesions. We found that p16/ki-67 dual-staining was valuable in identifying cervical CIN2+ lesions and reducing the missed diagnosis of CIN2+ in HPV negative patients. More than 96% of CIN2+ patients were positive for two or three tests of triple detection. Whole positive triple detection can effectively predict high grade cervical lesions. In conclusion, the triple detection can distinguish almost all cervical CIN2+ lesions. Our data put forward and highlight the feasibility and significance of triple detection in cervical lesion screening.

TP53, CDKN2A/P16, and NFE2L2/NRF2 regulate the incidence of pure- and combined-small cell lung cancer in mice

Studies have shown that Nrf2^E79Q/+ is one of the most common mutations found in human tumors. To elucidate how this genetic change contributes to lung cancer, we compared lung tumor development in a genetically-engineered mouse model (GEMM) with dual Trp53/p16 loss, the most common mutations found in human lung tumors, in the presence or absence of Nrf2^E79Q/+. Trp53/p16-deficient mice developed combined-small cell lung cancer (C-SCLC), a mixture of pure-SCLC (P-SCLC) and large cell neuroendocrine carcinoma. Mice possessing the LSL-Nrf2^E79Q mutation showed no difference in the incidence or latency of C-SCLC compared with Nrf2^+/+ mice. However, these tumors did not express NRF2 despite Cre-induced recombination of the LSL-Nrf2^E79Q allele. Trp53/p16-deficient mice also developed P-SCLC, where activation of the NRF2^E79Q mutation associated with a higher incidence of this tumor type. All C-SCLCs and P-SCLCs were positive for NE-markers, NKX1-2 (a lung cancer marker) and negative for P63 (a squamous cell marker), while only P-SCLC expressed NRF2 by immunohistochemistry. Analysis of a consensus NRF2 pathway signature in human NE⁺-lung tumors showed variable activation of NRF2 signaling. Our study characterizes the first GEMM that develops C-SCLC, a poorly-studied human cancer and implicates a role for NRF2 activation in SCLC development.

Comparative study of Rb1, cyclin D1 and p16 immunohistochemistry expression to distinguish lung small cell carcinoma and large cell neuroendocrine carcinoma

INTRODUCTION

Large cell neuroendocrine carcinoma (LCNEC) and small cell carcinoma (SCLC) of lung encompass high grade neuroendocrine tumour category and share several fundamental features. As both tumours may respond to different treatment modalities and show unique molecular alterations, distinction between the two is clinically relevant but can be challenging due to sampling and fixation issues, and shared morphologic features.

METHODS

Surgically resected primary SCLC (N=129) and LCNEC (N=27) were immunohistochemically stained with Rb1, cyclin D1 and p16, using tissue microarray (TMA), and expression patterns of the proteins were compared between the two to identify the discriminatory pattern.

RESULTS

All markers had high diagnostic accuracy; Rb1 was the highest followed by p16 and cyclin D1. Majority of SCLC had the pattern Rb1-/p16+/cyclin D1- and more than half of LCNEC had Rb1+/p16-/cyclin D1+. Overall, the expression pattern Rb1- and cyclin D1- was strongly associated with the diagnosis of SCLC, while the pattern Rb1+ and/or cyclin D1+ was strongly associated with LCNEC. The use of this simplified expression pattern leads to a diagnostic accuracy of 97.3%. p16 did not add to further discrimination. The heterogeneity in Rb1, cyclin D1 and p16 expression was insignificant in SCLCs compared with LCNECs.

CONCLUSIONS

Use of Rb1, cyclin D1 and p16 immunohistochemistry can distinguish the two with high accuracy. Notably, Rb1-/cyclin D1- pattern in given tumour sample would confirm the diagnosis of SCLC. Our results could be extrapolated and applied to routine diagnostic samples such as biopsies and cytology samples.

The Movember Global Action Plan 1 (GAP1): Unique Prostate Cancer Tissue Microarray Resource

BACKGROUND

The need to better understand the molecular underpinnings of the heterogeneous outcomes of patients with prostate cancer is a pressing global problem and a key research priority for Movember. To address this, the Movember Global Action Plan 1 Unique tissue microarray (GAP1-UTMA) project constructed a set of unique and richly annotated tissue microarrays (TMA) from prostate cancer samples obtained from multiple institutions across several global locations.

METHODS

Three separate TMA sets were built that differ by purpose and disease state.

RESULTS

The intended use of TMA1 (Primary Matched LN) is to validate biomarkers that help determine which clinically localized prostate cancers with associated lymph node metastasis have a high risk of progression to lethal castration-resistant metastatic disease, and to compare molecular properties of high-risk index lesions within the prostate to regional lymph node metastases resected at the time of prostatectomy. TMA2 (Pre vs. Post ADT) was designed to address questions regarding risk of castration-resistant prostate cancer (CRPC) and response to suppression of the androgen receptor/androgen axis, and characterization of the castration-resistant phenotype. TMA3 (CRPC Met Heterogeneity)'s intended use is to assess the heterogeneity of molecular markers across different anatomic sites in lethal prostate cancer metastases.

CONCLUSIONS

The GAP1-UTMA project has succeeded in combining a large set of tissue specimens from 501 patients with prostate cancer with rich clinical annotation.

IMPACT

This resource is now available to the prostate cancer community as a tool for biomarker validation to address important unanswered clinical questions around disease progression and response to treatment.

New molecular classification of large cell neuroendocrine carcinoma and small cell lung carcinoma with potential therapeutic impacts

Large cell neuroendocrine carcinoma (LCNECs) and small cell lung carcinomas (SCLCs) are high-grade neuroendocrine carcinomas of the lung with very aggressive behavior and poor prognosis. Their histological classification as well as their therapeutic management has not changed much in recent years, but genomic and transcriptomic analyses have revealed different molecular subtypes raising hopes for more personalized treatment. Indeed, four subtypes of SCLCs have been recently described, SCLC-A driven by the master gene ASCL1, SCLC-N driven by NEUROD1, SCLC-Y by YAP1 and SCLC-P by POU2F3. Whereas SCLC standard of care is based on concurrent chemoradiation for limited stages and on chemotherapy alone or chemotherapy combined with anti-PD-L1 checkpoint inhibitors for extensive stage SCLC, SCLC-A variants could benefit from DLL3 or BCL2 inhibitors, and SCLC-N variants from Aurora kinase inhibitors combined with chemotherapy, or PI3K/mTOR or HSP90 inhibitors. In addition, a new SCLC variant (SCLC-IM) with high-expression of immune checkpoints has been also reported, which could benefit from immunotherapies. PARP inhibitors also gave promising results in combination with chemotherapy in a subset of SCLCs. Regarding LCNECs, they represent a heterogeneous group of tumors, some of them exhibiting mutations also found in SCLC but with a pattern of expression of NSCLC, while others harbor mutations also found in NSCLC but with a pattern of expression of SCLC, questioning their clinical management as NSCLCs or SCLCs. Overall, we are probably entering a new area, which, if personalized treatments are effective, will also lead to the implementation in practice of molecular testing or biomarkers detection for the selection of patients who can benefit from them.

Application of p16/Ki-67 dual-staining cytology in cervical cancers

Cytology-based Papanicolaou test on and primary HPV screening have been widely used in the identification of cervical cancer and precancerous lesions, which is of great significance for the prevention and treatment of cervical cancer. Patients diagnosed as ASCUS/LSIL usually need follow-up because some of them may develop into CIN2+. The consequences of women positive for HPV vary from person to person; some of them may progress into cervical dysplasia, reversible forms of precancerous lesions, and eventually invasive cervical cancer. Therefore, it is necessary to establish an effective biomarker to triage different patients according to the preliminary screening results. p16 acts as a cell cycle regulatory protein that induces cell cycle arrest, and Ki-67 is a cell proliferation marker. Under physiological conditions, they could not co-express in the same cervical epithelial cells. The co-expression of these two molecules suggests a deregulation of the cell cycle mediated by HR-HPV infection and predicts the presence of high-grade cervical epithelial lesions. There is increasing evidence that p16/Ki-67 dual-staining cytology can be used as an alternative biomarker, showing overall high sensitivity and specificity for identifying high-grade CIN and cervical cancer. In this review, we discuss the significance of p16/Ki-67 dual-staining and summarize its application in the screening and triaging of cervical cancer and precancerous lesions.

Cytology Microarray on Cell Block Preparation: A Novel Diagnostic Approach in Fluid Cytology

Background:

The cytological examination of serous body effusions to diagnose and stage malignancy is well accepted in clinical medicine. Conventional smear (CS) and cell block (CB) study has to be complemented with immunohistochemistry (IHC) for a definitive diagnosis of malignancy and also to differentiate it from reactive mesothelial cells. Cytology microarray (CMA) is a modification of tissue microarray which involves core needle biopsy of multiple cell blocks and embedding it in a single block.

Aim:

The aim of this study was to assess the effectiveness of IHC technique in CMA for rapid diagnosis of malignancy and to reduce the cost of testing.

Materials and Methods:

In this study, 82 pleural fluids were collected and subjected to CS and CB study followed by IHC in CMA blocks. Six commonly used antibodies were applied to confirm malignancy and diagnose the primary.

Results:

Nineteen cases were diagnosed as malignancy by CB method. MOC-31 confirmed adenocarcinoma deposit in 67% cases of which 44% were proved to be of lung primary by TTF1.

Conclusions:

IHC on CMA blocks of effusion fluids is a very effective technique that can significantly reduce the cost of testing by >70%.

Tissue microarray is suitable for scientific biomarkers studies in endometrial cancer

The aim of this study was to define the concordance between tissue microarrays (TMAs) of different sizes and whole slide for 15 different antibodies in endometrial cancer and study the use of TMAs in preoperative endometrial samples. Cores of preoperative and hysterectomy specimens of 14 endometrial cancer and three atypical hyperplasia cases were collected in TMA blocks. Two 0.6-mm and two 2.0-mm cores were used from each sample. Different antibodies were tested in TMAs and compared with results of whole slides of hysterectomy. Tested antibodies were as follows: ER, PR, p53, Ki-67, MLH1, PMS2, MSH2, MSH6, ARID1A, stathmin, IMP3, L1CAM, PTEN, β-catenin, and p16. Seventeen cases with four cores per paraffin block (both 0.6 and 2.0 mm in duplicate) and 15 different antibodies resulted in a total of 1020 cores for both preoperative and hysterectomy specimen. Overall, 2.0-mm cores were more assessable for evaluation than 0.6-mm cores (96.0 versus 79.5%, p < 0.01). For most antibodies, a substantial to good agreement between hysterectomy TMA and whole slide was present, with lowest agreement for p16 and stathmin and perfect agreement for mismatch repair proteins. Preoperative TMAs showed for most antibodies moderate to perfect agreement with hysterectomy TMAs. In conclusion, 2.0-mm cores are the preferred size for immunohistochemical studies in endometrial cancer. For all tested antibodies, TMAs are a good alternative for whole slide analysis in scientific studies with large patient cohorts, even in preoperative endometrial samples. However, caution is required for interpretation of TMA results of p16 and stathmin.

Aberrant expression of p16INK4a in human cancers - a new biomarker?

The ARF and INK4a genes are located in the same CDKN2a locus, both showing its tumor suppressive activity. ARF has been shown to detect potentially harmful oncogenic signals, making incipient cancer cells undergo senescence or apoptosis. INK4a, on the other hand, responds to signals from aging in a variety of tissues including islets of Langerhans, neuronal cells, and cancer stem cells in general. It also detects oncogenic signals from incipient cancer cells to induce them senescent to prevent neoplastic transformation. Both of these genes are inactivated by gene deletion, promoter methylation, frame shift, and aberrant splicing although mutations changing the amino acid sequences affect only the latter. Recent studies indicated that polycomb gene products EZH2 and BMI1 repressed p16^INK4a expression in primary cells, but not in cells deficient for pRB protein function. It was also reported that that p14^ARF inhibits the stability of the p16^INK4a protein in human cancer cell lines and mouse embryonic fibroblasts through its interaction with regenerating islet-derived protein 3γ. Overexpression of INK4a is associated with better prognosis of cancer when it is associated with human papilloma virus infection. However, it has a worse prognostic value in other tumors since it is an indicator of pRB loss. The p16^INK4a tumor suppressive protein can thus be used as a biomarker to detect early stage cancer cells as well as advanced tumor cells with pRB inactivation since it is not expressed in normal cells.

P16 is a useful supplemental diagnostic marker of pulmonary small cell carcinoma in small biopsies and cytology specimens

Pulmonary small cell carcinoma (SCLC) is usually diagnosed in small biopsy or cytological specimens based on cytomorphology; however in ambiguous cases diagnosis requires additional support by immunohistochemistry. While TP53 and RB1 alterations with secondary overexpression of p16 are mainstay events in SCLC pathogenesis, diagnostic value of p16-positivity in the diagnosis of SCLC has not yet been fully investigated. We examined the expression of p16, CD56, synaptophysin (SYP), chromogranin A and thyroid transcription factor-1 (TTF1) in a series of pulmonary and extrapulmonary small cell carcinomas, pulmonary carcinoids and non-small cell lung carcinomas, and compared diagnostic performance of these markers in the diagnosis of SCLC. P16 was positive in 95 of 101 SCLCs, and displayed highest diagnostic sensitivity of ~94%. Composite biomarkers CD56+p16+TTF1 and CD56+p16+SYP were both able to detect correctly all SCLC cases. Importantly, three (~3%) SCLC cases completely negative for all conventional markers displayed diffuse positivity for p16. CD56 and p16 demonstrated highest concordance between paired small biopsy and cytology specimens. 50% of squamous cell carcinomas, ~41% of adenocarcinoma/NSCLC-favour adenocarcinoma cases, and ~93% of extrapulmonary small cell carcinomas also showed p16-positivity. Combination of CD56, p16 and TTF1 produced diagnostic classifier that outperformed best single marker CD56 in differential diagnosis between SCLC and NSCLC. In conclusion, in the appropriate morphological context p16 represents a useful supplementary marker for diagnosis of SCLC, even in cases where only cytological material is available.

Human papillomavirus infection in oral potentially malignant disorders and cancer

Human papillomavirus (HPV) infects keratinocytes in the mucosa or skin, and persistent infection with HPV may lead to premalignant lesions and invasive cancer, especially cervical cancer. It has also been hypothesized that HPV infection is an etiological factor of oral squamous cell carcinoma and oral precancerous disorders such as lichen planus, leukoplakia, and erythroplakia. A high percentage of HPV in oral lesions supports the possible viral contribution, but an association of HPV infection with these lesions remains to be established. The current paper will update the latest progress of HPV infection in several oral potentially malignant disorders and oral squamous cell carcinoma and discuss the impact of HPV infection on the progression of oral potentially malignant disorders.

The Use of Immunohistochemistry Improves the Diagnosis of Small Cell Lung Cancer and Its Differential Diagnosis. An International Reproducibility Study in a Demanding Set of Cases

INTRODUCTION

The current WHO classification of lung cancer states that a diagnosis of SCLC can be reliably made on routine histological and cytological grounds but immunohistochemistry (IHC) may be required, particularly (1) in cases in which histologic features are equivocal and (2) in cases in which the pathologist wants to increase confidence in diagnosis. However, reproducibility studies based on hematoxylin and eosin-stained slides alone for SCLC versus large cell neuroendocrine carcinoma (LCNEC) have shown pairwise κ scores ranging from 0.35 to 0.81. This study examines whether judicious use of IHC improves diagnostic reproducibility for SCLC.

METHODS

Nineteen lung pathologists studied interactive digital images of 79 tumors, predominantly neuroendocrine lung tumors. Images of resection and biopsy specimens were used to make diagnoses solely on the basis of morphologic features (level 1), morphologic features along with requested IHC staining results (level 2), and all available IHC staining results (level 3).

RESULTS

For the 19 pathologists reading all 79 cases, the rate of agreement for level 1 was 64.7%, and it increased to 73.2% and 77.5% in levels 2 and 3, respectively. With IHC, κ scores for four tumor categories (SCLC, LCNEC, carcinoid tumors, and other) increased in resection samples from 0.43 to 0.60 and in biopsy specimens from 0.43 to 0.64.

CONCLUSIONS

Diagnosis using hematoxylin and eosin staining alone showeds moderate agreement among pathologists in tumors with neuroendocrine morphology, but agreement improved to good in most cases with the judicious use of IHC, especially in the diagnosis of SCLC. An approach for IHC in the differential diagnosis of SCLC is provided.

Validation of Tissue Microarrays for Immunohistochemical Analyses of Canine Lymphomas

In most validation studies of tissue microarrays (TMAs), a fixed number of cores with a given diameter are analyzed to determine the degree of accuracy by which the TMA represents the whole section. The statistical model described in the present study predicts this property for various combinations of 2 core sizes (0.6 mm and 1.2 mm) and different core numbers. The model was based on artificial TMA core biopsies generated from Ki-67 and active caspase-3 immunostains of 40 canine lymphoma samples. Positivity was scored on a continuous scale, and a large number of cells were analyzed with the help of semiautomated cell counting. Despite considerable differences in range and distribution of Ki-67 and active caspase-3 positivity values, the model predictions showed a high degree of agreement for both markers. Comparison of 0.6 mm and 1.2 mm cores indicated that the use of small cores necessitates inclusion of a larger number of samples but requires counting a markedly smaller number of cells. Suitability of TMAs to determine the immunophenotype of the whole section was assessed using 2 different combinations of core sizes and numbers. Both displayed a high degree of concordance with the whole section (κ0.6 = 0.79; κ1.2 = 0.91). The present study provides a basis for the use of TMAs in future high-throughput immunohistochemical investigations of selected markers in canine lymphomas. The statistical model presented can be used to determine an optimal TMA design depending on a desired accuracy.

Digital pathology for the validation of tissue microarrays in peripheral T-cell lymphomas

Systematic validation of construction and analysis parameters when using tissue microarray (TMA) in rare, morphologically heterogenous entities such as peripheral T-cell lymphoma (PTCL) is not reported. We describe a tissue-saving virtual TMA to predetermine the number of cores needed to represent whole tissue sections (WTS) from the same biopsies, using automated and traditional manual methods for the quantification of immunohistochemical stains. Whole paraffin hematoxylin and eosin- and immunohistochemical (CD2, CD30, and Ki-67)-stained sections from 30 PTCLs were digitalized. A virtual TMA with six 1-mm cores per slide was designed to compare agreements in the immunohistochemical scoring. Using digital image analysis and manual stereological counting, immunohistochemical positivity was quantified. Associations were analyzed using the Bland-Altman and correlation plots. In PTCL, we report that 4 cores are required to represent WTS results (ie, agreement within ±10%). High concordance was demonstrated between digital results obtained with WTS compared with 4-core virtual TMA (correlation coefficients: 0.89-0.98), and in the comparative evaluation of 4-core virtual TMA by digital image analysis versus manual stereology (correlation coefficients: 0.91 to 0.99). Virtual TMAs provide an efficient tool for optimizing and validating TMA construction parameters when planning a study. The method can be applied to the same tissues used in a subsequent formal study, without wasting scarce tissue resources. In PTCL, TMAs constructed with four 1-mm cores are representative of WTS. In parallel tests using TMAs and WTS from PTCLs, there is a high level of agreement comparing automated digital with manual stereological methods for the quantification of immunohistochemical biomarker staining.

Expression of girdin in human colorectal cancer and its association with tumor progression

BACKGROUND

Girdin is crucial for cellular motility in cancer cell lines and for metastasis in a mouse model. Its expression has been demonstrated in a range of cancers by a few studies and was a prognostic factor in a subset of patients.

OBJECTIVE

The aim of this study was to investigate the relationship of Girdin expression to clinicopathologic factors in terms of the progression of colorectal cancers and patient survival.

DESIGN

This study is a retrospective review of immunohistochemical and clinicopathologic data.

SETTING

This study was conducted at a tertiary care hospital/referral center in South Korea.

PATIENTS

Tissue microarrays were made from surgical biopsies of 298 patients with colorectal cancer diagnosed between November 1996 and August 2007. Patients were included in the study if their survival time was known and if well-preserved surgical biopsy specimens were available.

MAIN OUTCOME MEASURES

The primary outcomes measured were Girdin expression and its association in tumor progression and patient survival.

RESULTS

Positive staining for Girdin was observed in samples from 66 of 242 patients (27.3%). Expression of Girdin was significantly associated with tumor-node-metastasis stage (p = 0.036), liver metastasis (p = 0.025), and metastases involving the liver and other organs (p = 0.009). However, Girdin expression did not correlate significantly with the overall survival of patients and was not a significant negative prognostic factor for survival by univariate or multivariate analyses.

LIMITATIONS

The number of investigated patients and the number of cases with positive staining for Girdin were rather small for the multivariate analysis. The inclusion time frame is long and includes other surgical and medical improvements, which influence a patient's survival.

CONCLUSION

The expression of Girdin is related to tumor metastasis but not to survival in human colorectal cancers.

Tissue microarray construction for salivary gland tumors study

OBJECTIVE

To describe and discuss the design, building and usefulness of tissue microarray (TMA) blocks for the study of salivary gland tumors (SGTs).

STUDY DESIGN

Two hundred thirty-eight formalin-fixed, paraffin-embedded SGTs were arranged in blocks of TMA using a manual tissue arrayer. Three representative cores of 1.0, 2.0 or 3.0mm were taken from each original block and their characteristics were analyzed and described.

RESULTS

It was created 12 TMA blocks that presented highly representative neoplastic cylinders. However, those neoplasias rich in cystic spaces such as mucoepidermoid carcinoma and Warthin tumor presented more difficulties to be sampled, as the neoplastic tissue available was scarce. Tissue damage and loss during TMA construction was estimated as 3.7%.

CONCLUSION

Representative areas of SGTs, with relatively small loss of tissue, can be obtained with the construction of TMA blocks for molecular studies. However, tumors rich in cystic spaces present more difficulties to be adequately sampled.

The Utility of p16INK4a and Ki-67 as a Conjunctive Tool in Uterine Cervical Lesions

Background

Immunohistochemical staining for p16INK4a and Ki-67 has been used to improve the accuracy in making a diagnosis of the uterine cervix cancer on biopsy. This study was conducted to examine the usefulness of these markers in the pathological diagnosis based on cervical biopsy.

Methods

We selected a consecutive series of 111 colposcopically directed cervical punch biopsies. Using these biopsy samples, we performed an immunohistochemical staining for p16INK4a and Ki-67 to establish a diagnosis. The slides were circulated among four pathologists in a sequential order: the hematoxylin and eosin (H&E) slide, H&E slide and p16INK4a-stained slide, and H&E slide, p16INK4a- and Ki-67-stained slides.

Results

The overall rates of the concordance in the first, the second, and the third diagnoses were 77.5%, 82.0%, and 82.0%, respectively. The rate of the concordance in the diagnosis of cervical intraepithelial neoplasm (CIN) 2/3 was increased from 62.2% to 73.0%. But there was a variability in the rate of the revision of the diagnosis between the pathologists. With the application of criteria for interpreting the expressions of p16INK4a and Ki-67, benign and CIN 1 lesions showed a p16INK4a expression score of 0 or 1. But CIN 2 and CIN 3 lesions showed a p16INK4a expression score of 2 and 3, respectively.

Conclusions

The immunostain for p16INK4a and Ki-67 might be useful in reducing an inter-observer variability. But criteria for interpreting both markers should be strictly applied.

Tubulin, BRCA1, ERCC1, Abraxas, RAP80 mRNA expression, p53/p21 immunohistochemistry and clinical outcome in patients with advanced non small-cell lung cancer receiving first-line platinum-gemcitabine chemotherapy

BACKGROUND

The aim of this study was to assess the predictive value of tumor expression of nine genes on clinical outcome in patients with advanced NSCLC receiving platinum-gemcitabine chemotherapy.

METHODS

Quantitative PCR or immunohistochemistry were used to analyze the expression of β-tubuline IIA (TUBB2A), β-tubuline III (TUBB3), BRCA1, ERCC1, Abraxas (ABRX) and RAP80 in mRNA isolated from paraffin-embedded tumor biopsies of 45 NSCLC patients treated as part of a larger observational trial. All patients received first-line platinum-gemcitabine chemotherapy for stage IIIB or IV NSCLC.

RESULTS

Median progression-free survival (PFS) was 7 months, overall survival (OS) 12 months. A partial treatment response was found in 14 patients (33%). Patients with low ERCC1 or ABRX expression had a significantly better response to chemotherapy (R=-0.45, p<0.01 for ERCC1; R=-0.40, p=0.016 for ABRX). A significant correlation was found between the individual time for PFS and the expression of both ERCC1 (R=-0.36, p=0.015) and ABRX (R=-0.46, p=0.001). Patients with low ERCC1 expression had a longer OS as compared to patients with high ERCC1 expression (HR=0.26, log-rank p=0.02).

CONCLUSIONS

The study confirms tumor expression of ERCC1 as a predictor for clinical outcome in patients with advanced NSCLC receiving platinum-based chemotherapy, and found ABRX expression to be similarly predictive of clinical outcome. Prospective validation is warranted and - if confirmed - non platinum-containing chemotherapy should be explored as the preferred treatment in patients with high ERCC1 or ABRX expression and no activating mutations of EGFR.

p16 immunocytochemistry on cell blocks as an adjunct to cervical cytology: Potential reflex testing on specially prepared cell blocks from residual liquid-based cytology specimens

Background:

p16 ^INK4a (p16) is a well-recognized surrogate molecular marker for human papilloma virus (HPV) related squamous dysplasia. Our hypothesis is that the invasive interventions and related morbidities could be avoided by objective stratification of positive cytologic interpretations by p16 immunostaining of cell block sections of cytology specimens.

Materials and Methods:

Nuclear immunoreactivity for p16 was evaluated in cell block sections in 133 adequate cases [20 negative for intraepithelial lesion or malignancy, 28 high-grade squamous intraepithelial lesion (HSIL), 50 low-grade squamous intraepithelial lesion (LSIL), 21 atypical squamous cells, cannot exclude HSIL (ASC-H), and 14 atypical squamous cells of undetermined significance (ASCUS)] and analyzed with cervical biopsy results.

Results:

(a) HSIL cytology (28): 21 (75%) were p16 positive (11 biopsies available — 92% were positive for cervical intraepithelial neoplasia (CIN) 1 and above) and 7 (25%) were p16 negative (3 biopsies available — all showed only HPV with small atypical parakeratotic cells). (b) LSIL cytology (50): 13 (26%) cases were p16 positive (12 biopsies available — all were CIN1 or above) and 37 (74%) were p16 negative (12 biopsies available — all negative for dysplasia. However, 9 (75%) of these biopsies showed HPV). (c) ASC-H cytology (21): 14 (67%) were p16 positive (6 biopsies available — 5 showed CIN 3/Carcinoma in situ/Ca and 1 showed CIN 1 with possibility of under-sampling. Cytomorphologic re-review favored HSIL) and 7 (33%) were p16 negative (5 biopsies available — 3 negative for dysplasia. Remaining 2 cases — 1 positive for CIN 3 and 1 showed CIN 1 with scant ASC-H cells on cytomorphologic re-review with possibility under-sampling in cytology specimen). (d) ASCUS cytology (14): All (100%) were p16 negative on cell block sections of cervical cytology specimen. HPV testing performed in last 6 months in 7 cases was positive in 3 (43%) cases.

Conclusion:

p16 immunostaining on cell block sections of cervical cytology specimens showed distinct correlation patterns with biopsy results. Reflex p16 immunostaining of cell blocks based on the algorithmic approach to be evaluated by a multiinstitutional comprehensive prospective study is proposed.

Limitations of tissue microarrays compared with whole tissue sections in survival analysis

Tissue microarray (TMA) is a promising technique in the evaluation of immunohistochemical markers in tumors and may be used as an alternative for whole sections. However, only a few studies have correlated a clinical outcome with both TMA and results obtained from whole sections. This study compared immunostaining for Ki-67 and p16 in TMA (3 cores from each specimen) and whole sections of 171 cases of stage III epithelial ovarian cancer with clinical data. A high expression of Ki-67 was identified in 85.0, 85.5, 85.8, 90.5 and 84% of cores 1, 2 and 3, TMAs and whole tissue sections, respectively. A high p16 expression was found in 36.5, 31.4, 30.3, 46.3 and 31.0% of cores 1, 2 and 3, TMAs and whole tissue sections, respectively. The high expression of Ki-67 and p16 in whole tissue sections significantly correlated with that of Ki-67 and p16 in core 1 (P<0.0001 and P<0.0001, respectively), core 2 (P<0.0001 and P<0.0001, respectively), core 3 (P<0.0001 and P<0.0001, respectively), and TMAs (P<0.0001 and P<0.0001, respectively). In univariate analysis, a high expression of Ki-67 and p16 in two of the cores; TMA and the whole tissue sections were significantly correlated to disease-related survival (Ki-67: P=0.008, 0.012, 0.012 and 0.0001, respectively, and p16: P=0.0007, 0.0005, 0.0008 and 0.005, respectively). However, in the multivariate analysis only Ki-67 on whole tissue sections retained an independent prognostic significance (P=0.025). We concluded that more studies, with a higher number of cores, are necessary to determine the efficacy of TMA in reflecting the prognostic value of different antibodies. Morever, evaluation of this method is crucial for each type of tumor and each separate antigen. It is also essential to confirm the clinical correlations on the whole sections before investigating the same parameters on TMA.

Expression of protease activated receptor-2 in human colorectal cancer and its association with tumor progression

PURPOSE

Protease activated receptor-2 has been reported to promote the proliferation of colorectal cancer cells. The aim of this study was to investigate the relationship of protease activated receptor-2 expression to clinicopathologic factors to clarify its role in tumor progression and patient survival in human colorectal cancer.

METHODS

Immunohistochemical staining with anti-protease activated receptor-2 antibody was carried out and evaluated on samples from 295 patients with colorectal cancer obtained during surgical treatment at Kangnam St. Mary's Hospital, Seoul, Republic of Korea. Medical records were reviewed and relationships between immunostaining and clinicopathologic findings were evaluated.

RESULTS

Positive staining for protease activated receptor-2 was observed in samples from 100 patients (33.9%). Expression of protease activated receptor-2 was significantly associated with depth of tumor invasion (P = .013), liver metastasis (P = .008), TNM stage (P = .009), and tumor location (P = .011). However, protease activated receptor-2 expression did not significantly correlate with overall survival of patients and was not a significant negative prognostic factor for survival in univariate or multivariate analyses.

CONCLUSIONS

The expression of protease activated receptor-2 is related to tumor invasion and metastasis in human colorectal cancer. However, further studies are needed to clarify the role of protease activated receptor-2 in the prognosis of patients with colorectal cancer.

Diagnostic value of p16INK4A, Ki-67, and human papillomavirus L1 capsid protein immunochemical staining on cell blocks from residual liquid-based gynecologic cytology specimens

BACKGROUND

This study was conducted to evaluate the reliability and role of cell block preparations in the diagnosis of neoplastic and preneoplastic lesions of the cervix and to improve the value of cell block preparations in diagnosing and predicting the prognosis of cervical lesions through immunostaining of p16INK4A (p16), Ki-67, and human papillomavirus (HPV) L1 capsid protein (HPV L1).

METHODS

In total, 138 specimens were diagnosed on liquid-based cytology (LBC) and cell block preparations, and 63 specimens were subjected subsequently to tissue follow-up and immunostaining for p16, Ki-67, and HPV L1 on cell block sections.

RESULTS

In 42 specimens that were diagnosed as low-grade squamous intraepithelial lesion, high-grade squamous intraepithelial lesion (HSIL), and squamous cell carcinoma (SCC) on cell blocks, 38 specimens (90.5%) were confirmed by histopathologic reports, and there was slightly better than 81.6% agreement between LBC and tissue follow-up. Immunointensity and cells that were positive for p16 were enhanced according to increased pathologic grade and differed statistically between cervical intraepithelial neoplasia 1 (CIN-1) and CIN-2/CIN-3 as well as SCC. The positive rates of HPV L1 decreased gradually according to the severity of cervical neoplasia, and HPV L1/p16 expression patterns were related to the severity of cervical lesions.

CONCLUSIONS

The cell block preparation technique was complementary to LBC, and the authors concluded that the application of LBC combined with cell block preparations may improve the diagnostic accuracy of cytology. Immunostaining for p16 and Ki-67 on cell block preparations can help to improve the diagnostic accuracy of HSIL and SCC. A combined expression pattern of p16 and HPV L1 may serve as a valuable index for predicting prognosis and follow-up of cervical dysplastic lesions.

Validation of tissue microarray immunohistochemistry staining and interpretation in diffuse large B-cell lymphoma

Tissue microarrays (TMAs) show concordance with whole tissue sections in the immunohistochemical evaluation of tumor cells. However, potential inter-institutional variability among observers and immunohistochemical staining methods has not been fully addressed. We selected 21 cases of diffuse large B-cell lymphoma (DLBCL) to process for TMAs. Immunohistochemical stains were performed in 3 laboratories, and reviewed independently by 3 hematopathologists at the 3 institutions. Stains were scored on a 4-point scale. Statistical analyses of variation in the scoring among observers and among different institutions' stains were performed. Stains for CD3, CD10, CD20, BCL-2, BCL-6, MIB-1, and FOX-P1 revealed little variation among observers, with an average 51-82% complete agreement and 82-100% agreement +/- 1 numerical score. The rate of concordance when evaluating most stains performed in different laboratories was also relatively good, with an average of 55-72% complete agreement and 70-97% agreement +/- 1 score. However, scoring of MUM-1 and p53 stains showed wider variation, with an average of only 37 and 30% complete agreement among observers, and 11 and 45% agreement when stains from different institutions were examined. Further statistical analyses were performed to compare the observers' scoring of their own institution's stains (self-review) vs. observers' scoring of other institutions' stains (non-self). The agreement rate for the p53 stain was significantly higher when based on self-review (average 58% complete agreement) compared with an agreement rate of only 10.5% when based on a review of stains performed in another laboratory, non-self review, P < 0.01. This difference in the self- vs. non-self review was not seen when data for MUM-1 were analysed. In conclusion, most phenotypic markers used in the analysis of DLBCL can be evaluated in TMAs with adequate agreement among observers and laboratories. These include CD3, CD20, CD10, BCL-2, BCL-6, MIB-1, and FOX-P1. However, some markers, such as p53 and MUM-1, are more prone to inter-institutional variation. Variations in interpretation can be partially overcome by self-adjusted/adapt tendency, as seen with p53. Especially with newly developed markers, such as MUM-1, the development of standardized techniques for staining and interpretation is critical to reduce inter-observer variability.

miR-15a and miR-16 are implicated in cell cycle regulation in a Rb-dependent manner and are frequently deleted or down-regulated in non-small cell lung cancer

MicroRNAs (miRNA) are negative regulators of gene expression at the posttranscriptional level, which are involved in tumorigenesis. Two miRNAs, miR-15a and miR-16, which are located at chromosome 13q14, have been implicated in cell cycle control and apoptosis, but little information is available about their role in solid tumors. To address this question, we established a protocol to quantify miRNAs from laser capture microdissected tissues. Here, we show that miR-15a/miR-16 are frequently deleted or down-regulated in squamous cell carcinomas and adenocarcinomas of the lung. In these tumors, expression of miR-15a/miR-16 inversely correlates with the expression of cyclin D1. In non-small cell lung cancer (NSCLC) cell lines, cyclins D1, D2, and E1 are directly regulated by physiologic concentrations of miR-15a/miR-16. Consistent with these results, overexpression of these miRNAs induces cell cycle arrest in G(1)-G(0). Interestingly, H2009 cells lacking Rb are resistant to miR-15a/miR-16-induced cell cycle arrest, whereas reintroduction of functional Rb resensitizes these cells to miRNA activity. In contrast, down-regulation of Rb in A549 cells by RNA interference confers resistance to these miRNAs. Thus, cell cycle arrest induced by these miRNAs depends on the expression of Rb, confirming that G(1) cyclins are major targets of miR-15a/miR-16 in NSCLC. Our results indicate that miR-15a/miR-16 are implicated in cell cycle control and likely contribute to the tumorigenesis of NSCLC.

BCCIP as a prognostic marker for radiotherapy of laryngeal cancer

BACKGROUND

Recent studies have shown that BCCIP (BRCA2 and CDKN1A interacting protein) is essential for maintaining the transactivation activity of wild type p53. We analyzed the expression of BCCIP and p53 in a cohort of laryngeal cancer treated with radiotherapy and assessed whether BCCIP and p53, alone or in combination, would correlate with local control and overall survival.

METHODS

One hundred twenty-three patients treated between 1975 and 2000 for early stage (stages I and II) squamous cell carcinoma of the larynx were included in the study. Treatment consisted of radiation therapy (RT) with standard fields and fractionation to a median dose of 66Gy. Tissue was collected from pre-RT biopsies and constructed in a tissue microarray, and BCCIP expression and p53 expression were determined using immunohistochemistry.

RESULTS

Loss of expression of BCCIP in combination with normal p53 (negative p53 staining) was associated with local recurrence (RR 2.04; 95% CI 0.99-4.56, p=0.05) and poor overall survival (RR 2.09; 95% CI 1.21-4.00, p=0.008) compared to patients who did express BCCIP. Expression of BCCIP or p53 alone was not found to be independently associated with benefits in local control or overall survival.

CONCLUSIONS

This study provides clinical evidence that BCCIP contributes to outcomes in patients with laryngeal cancer treated with RT. This benefit may be a result of increased radiosensitivity in patients who have functional BCCIP and p53. These data may be used to identify sub-groups of laryngeal cancer patients who are more likely to be cured with radiotherapy.

Tissue microarrays in clinical oncology

Tissue microarray (TMA) is a recently implemented, high-throughput technology for the analysis of molecular markers in oncology. This research tool permits the rapid assessment of a biomarker in thousands of tumor samples, using commonly available laboratory assays such as immunohistochemistry and in situ hybridization. Although introduced less than a decade ago, TMA has proven to be invaluable in the study of tumor biology, the development of diagnostic tests, and the investigation of oncologic biomarkers. This review describes the impact of TMA-based research in clinical oncology and its potential future applications. Technical aspects of TMA construction and the advantages and disadvantages inherent to this technology are also discussed.

Outcomes in Young Women With Breast Cancer of Triple-Negative Phenotype: The Prognostic Significance of CK19 Expression

PURPOSE

Basal-like carcinoma of the breast is associated with genetic instability and aggressive behavior. In this study, we evaluated the luminal cytokeratin marker CK-19 in young women with breast cancer treated with conservative surgery and radiation therapy (CS+RT).

METHODS

Primary tumor specimens from a cohort of 158 young premenopausal women (range, 25-49 years) treated with CS+RT with a median follow-up of 6.25 years were constructed into a tissue microarray. The array was stained for ER, PR, HER2, CK19, and p53. The molecular profiles were correlated with clinical-pathologic factors, overall, local, and distant relapse-free survival. The association between CK19, other co-variables, and outcome was assessed in a multivariate model.

RESULTS

Positive expression of ER, PR, HER-2/neu, CK19, and p53 were 33.1%, 34.5%, 10.0%, 79.5%, and 20.9%, respectively. With 20 local relapses and 38 distant metastases, the 10-year overall, breast relapse-free, and distant relapse-free survival were 79.65%, 87.29%, and 67.35%, respectively. Tumor stage and nodal status were associated with distant relapse-free and overall survival. In multivariate analysis, CK19 negativity was a predictor poor local (RR, 3.54; 95% CI, 1.87-7.65; p < 0.01) distant (RR, 1.44; 95% CI, 0.86-2.70; p = 0.17), and overall survival (RR, 1.89; 95% CI, 1.04-3.55; p = 0.03).

CONCLUSIONS

Lack of CK19 expression identifies a subset of patients with a significantly higher risk of local relapse. Distant relapse and overall survival rates also correlated with CK19 negativity. Further evaluation of the prognostic significance of basal and luminal cytokeratins in young women with breast cancer is warranted.

Prognostic and predictive importance of p53 and RAS for adjuvant chemotherapy in non small-cell lung cancer

PURPOSE

p53 and RAS are multifunctional proteins that are critical to cell cycle regulation, apoptosis, cell survival, gene transcription, response to stress, and DNA repair. We have evaluated the prognostic and predictive value of p53 gene/protein aberrations using tumor samples from JBR.10, a North American phase III intergroup trial that randomly assigned 482 patients with completely resected stage IB and II non-small-cell lung cancer (NSCLC) to receive four cycles of adjuvant cisplatin plus vinorelbine or observation alone.

METHODS

p53 protein expression was evaluated by immunohistochemistry. Mutations in exons 5 to 9 of the p53 gene were determined by denaturing high-performance liquid chromatography and confirmed by sequencing. RAS mutations were identified by allelic specific oligonucleotide hybridization.

RESULTS

Of 253 patients, 132 (52%) were positive for p53 protein overexpression. Untreated p53-positive patients had significantly shorter overall survival than did patients with p53-negative tumors (hazard ratio [HR] = 1.89; 95% CI, 1.07 to 3.34; P = .03). However, these p53-positive patients also had a significantly greater survival benefit from adjuvant chemotherapy (HR = 0.54; P = .02) compared with patients with p53-negative tumors (HR = 1.40; P = .26; interaction P = .02). Mutations of p53 and RAS genes were found in 124 (31%) of 397 and 117 (26%) of 450 patients, respectively. Mutations in these genes were neither prognostic for survival nor predictive of a differential benefit from adjuvant chemotherapy.

CONCLUSION

p53 protein overexpression is a significant prognostic marker of shortened survival, and also a significant predictive marker for a differentially greater benefit from adjuvant chemotherapy in completely resected NSCLC patients.

Aberrant methylation of multiple genes in gastric carcinomas

In this study, we examined aberrant methylation of the E-cadherin, estrogen receptor, RB1 , p16, p15, p14, and MGMT genes by the methylation-specific polymerase chain reaction method in 101 gastric carcinomas. Hypermethylation was detected in E-cadherin, estrogen receptor, RB1, p16, p14, p15, and MGMT at the rates of 27.7%, 44.6%, 44.6%, 30.7%, 19.2%, 7.7%, and 6.9%, respectively. A total of 82.2% cases had methylation in at least 1 of these genes, and 44.6% had methylation in 2 or more of these genes. Methylation of RB1 was associated with absence of lymph node metastasis. Methylation of estrogen receptor was associated with age and tumor location. Methylation of E-cadherin coincided with methylation of p16 or estrogen receptor. Moreover, loss of p16 protein was strongly associated with its gene methylation. This study indicates that aberrant methylation of multiple genes is involved in gastric carcinogenesis.

Immunophenotypic profiling of nonsmall cell lung cancer progression using the tissue microarray approach

This study, using tissue microarrays, aimed at the immunomorphologic profiling of nonsmall cell lung cancer (NSCLC) cases to reveal clinically relevant disease groups and biomarkers associated with patients' survival and tumor progression including brain metastatic potential. Donor tissue blocks were form 59 patients, including 33 primary tumors without distant metastasis and 26 brain metastatic primary tumors as well as the brain metastases. Sections were immunostained for 29 markers targeting molecules of cell adhesion, cell growth, cell cycle, and apoptosis regulation. beta-Catenin expression was the only independent prognostic marker associated with better outcome. Elevated expression of collagen XVII, CD44v6, and caspase-9, and the reduced production of beta-catenin and cellular apoptosis susceptibility protein were significantly associated with the metastatic potential of primary NSCLC. Expression of positive cell cycle regulators cyclin D1 and cyclin D3 was also increased in metastatic primary tumors. Metastatic tumor progression into the brain was accompanied by prominent p16, syndecan-1, p53 (DO7), and caspase-3 protein levels. Hierarchical clustering of complex immunoprofiles based on the differentially expressed markers grouped NSCLCs of the poorest outcome with high correlation including 2/3 of brain metastases of mixed histology. The brain metastatic potential of NSCLCs may be linked to the elevated levels of cyclinD1, cyclinD3, p16, p53, caspase-3, caspase-9, CD44v6, and collagen XVII and the down-regulation of beta-catenin and cellular apoptosis susceptibility protein. Unsupervised immunoprofiles based on differentially expressed biomarkers may help selecting lung cancers with aggressive behavior.

Prognostic significance of vascular endothelial growth factor protein levels in T1-2 N0 laryngeal cancer treated with primary radiation therapy

BACKGROUND

The purpose of this study was to assess the prognostic value of vascular endothelial growth factor protein levels in a large cohort of patients with T1-T2 N0 laryngeal cancer treated with primary radiation therapy (XRT).

METHODS

Primary tumor specimens from a cohort of 123 patients with T1-T2 N0 laryngeal cancer treated with XRT between 1975 and 2000 were constructed into a tissue microarray. Clinical prognostic factors included age, sex, T classification, and tumor subsite. Molecular prognostic factors included vascular endothelial growth factor, epidermal growth factor receptor, and p53 expression, determined by using immunohistochemistry on tissue microarrays. The association between vascular endothelial growth factor status, covariables, and outcome was assessed.

RESULTS

With a median follow-up of 9.9 years, 32 (26%) were diagnosed with local relapse (5-year local relapse-free rate, 70.4%). T2 tumor stage (31.7%) was a significant predictor of local relapse (relative risk [RR], 1.71; 95% confidence interval [CI], 1.21-2.43; P<.05). Positive expression of vascular endothelial growth factor, epidermal growth factor receptor, and p53 were: 8.5%, 58.7%, and 36.4%, respectively. In univariate analysis, vascular endothelial growth factor positivity was a significant predictor of overall survival (RR = 1.62; 95% CI, 0.99-2.42; P = .05). In multivariate analysis, positive vascular endothelial growth factor status maintained significant correlation with overall survival (RR, 2.79; 95% CI, 1.49-4.95; P = .002).

CONCLUSIONS

Vascular endothelial growth factor positivity appeared to be a significant predictor of overall survival in a multivariate model. Further evaluation of vascular endothelial growth factor-positive laryngeal cancers treated with primary XRT is warranted.

Immunohistochemical expressions of Ki-67, cyclin D1, beta-catenin, cyclooxygenase-2, and epidermal growth factor receptor in human colorectal adenoma: a validation study of tissue microarrays

BACKGROUND

Tissue microarray (TMA) holds promise as a high-throughput method for the analysis of biomarkers in tissue specimens. The validity and reliability of this method, however, may vary for different biomarkers in different tissue specimens.

OBJECTIVES

In this study, we evaluated the validity and reliability of using TMA to assess biomarkers in colorectal adenomas.

METHODS

Sixty-three consecutive patients with colorectal adenomas were recruited in this study. Two TMA blocks were constructed using four punches from each adenoma (one periphery, one deep, and two middle zones). The immunostaining of five markers (Ki-67, cyclin D1, beta-catenin, cyclooxygenase-2, and epidermal growth factor receptor) was analyzed, and the concordance between data obtained from TMAs and standard whole-tissue sections was evaluated by Spearman's correlation and kappa analysis.

RESULTS

Colorectal adenoma exhibited zonal, heterogeneous expression patterns for all five markers. The concordance rates for the semiquantitative evaluation of markers between data from TMAs and whole sections ranged from 87% to 93% with corresponding kappa statistics of 77% to 90%. In addition, both quantitative and semiquantitative methods were used to score TMA sections, and good correlations between these two methods were shown for all five markers with intraclass correlation coefficients ranging from 0.5 to 0.8.

CONCLUSION

Our study indicates that TMA can be used to reliably assess the expression levels of Ki-67, cyclin D1, beta-catenin, cyclooxygenase-2, and epidermal growth factor receptor in colorectal adenoma tissues.

Regulation of the G1/S phase of the cell cycle and alterations in the RB pathway in human lung cancer

The retinoblastoma (RB)-Cyclin (CCN)D1-p16 cell cycle pathway has a crucial role in lung tumorigenesis. Impairment of the RB pathway has been shown to occur in almost all lung tumors. A deregulation at any level of this core RB pathway seems to make cells insensitive to the mitogenic signaling that is required for cell cycle progression. To date, almost all participants in this pathway have been shown to be altered to a various degree in lung tumors. Some of the alterations are mutually exclusive, including RB and p16INK4A . In small cell lung cancer, the RB tumor suppressor gene is inactivated in almost 90% of the tumors, whereas in non-small cell lung cancer, the cyclin-dependent kinase (CDK)4 inhibitor p16INK4A is inactivated in 40-60% of the tumors. Many mechanisms may be responsible for activating the RB-Cyclin D1 pathway, including activating (CDK4) and inactivating mutations (p16INK4A ), deletions (RB and p16INK4A ), amplifications (CCND1 and CDK4), silencing methylation (p16INK4A and RB), and hyper-phosphorylation (RB). As some of these alterations, such as p16INK4A methylation, can also be detected in bronchial lavage and serum, they could potentially serve as useful markers for the early detection of lung cancer. This review summarizes recent experiments describing the variable roles of key-player molecules of the RB pathway and different mechanisms by which the RB pathway can be altered in lung cancer.

p16INK4a immunoexpression: surrogate marker of high-risk HPV and high-grade cervical intraepithelial neoplasia

p16INK4a has emerged as a valuable surrogate marker for high-risk human papillomavirus infection and shows increased immunoexpression with worsening grades of cervical intraepithelial neoplasia (CIN). Numerous studies have emerged in recent years supporting its role in the detection of high-grade dysplasia and have lead to the use of p16INK4a immunohistochemistry in many laboratories. However, only a few studies have examined the possible predictive or prognostic value of p16INK4a in CIN or cervical cancer. This review addresses some of the practical issues in the application of p16INK4a in everyday practice, with an emphasis on integrating the extensive data that have emerged in the literature on p16INK4a immunoreactivity in CIN. The potential role of p16INK4a immunohistochemistry in the prediction of CIN progression is also discussed.

Genomic analysis defines a cancer-specific gene expression signature for human squamous cell carcinoma and distinguishes malignant hyperproliferation from benign hyperplasia

Using high-density oligonucleotide arrays, we measured expression of >12,000 genes in surgical excisions of invasive human squamous cell carcinomas (SCCs) versus site-matched control skin. This analysis defined >1,900 genes with altered expression in SCCs that were statistically different from controls. As SCCs are composed of epithelial cells, which are both hyperplastic and invasive, we sought to define gene sets associated with these biologic processes by comparing gene expression to psoriasis vulgaris, which is a condition of benign keratinocyte hyperplasia without invasiveness or pre-malignant potential. Through this analysis, we found genes that were commonly upregulated in both conditions and unique genes with increased expression in SCCs. Differential gene regulation in these two conditions was confirmed by real-time reverse transcription-PCR and immunohistochemistry. We found that benign hyperplasia is associated with upregulation of genes including DEFB4 (defensin B4), SERPINB3 (serine proteinase inhibitor, member 3), STAT1 (signal transducer and activator of transcription 1), K16 (keratin 16), CEACAMs (carcinoembryonic antigen-related cell adhesion molecules), and WNT 5A (wingless-type MMTV integration site family, member 5A). WNT receptor frizzled homolog 6 (FZD6) and prostaglandin-metabolizing enzyme hydroxyprostaglandin dehydrogenase were increased in SCC alone. Growth factor pleiotrophin (PTN) was expressed at higher levels in non-tumor-bearing skin adjacent to excised SCC. SCC was further characterized by upregulation of matrix metalloproteinases 1, 10, and 13, cathepsin L2, cystatin E/M as well as STAT3 and microseminoprotein, beta (MSMB), and downregulation of inducible nitric oxide synthase, granzyme B, CD8, and CD83. The current study defines a unique gene expression signature for cutaneous SCC in humans and suggests potential roles for WNT, FZD, and PTN in the pathogenesis of SCC.

Advances in cancer tissue microarray technology: Towards improved understanding and diagnostics

Over the past few years, tissue microarray (TMA) technology has been established as a standard method for assessing the expression of proteins or genes across large sets of tissue specimens. It is being adopted increasingly among leading research institutions around the world and utilized in cancer research in parallel with the cDNA microarray technology. This article summarizes various aspects of cancer understanding and diagnostics in which TMA has had great impact. Although tremendous advances continue to be made to facilitate imaging and archiving of TMA specimens, automatic evaluation and quantitative analysis of TMA still remains an important challenge for modern investigators.

p16 expression in the female genital tract and its value in diagnosis

p16 is a cyclin-dependent kinase-4 inhibitor that is expressed in a limited range of normal tissues and tumors. In recent years, immunohistochemistry with p16 antibodies has been used as a diagnostic aid in various scenarios in gynecologic pathology. Diffuse (as opposed to focal) positivity with p16 in the cervix can be regarded as a surrogate marker of the presence of high-risk human papillomavirus (HPV). In cervical squamous lesions, p16 is positive in most high-grade cervical intraepithelial neoplasia (CIN) and in some cases of low-grade CIN, usually those associated with high-risk HPV. p16 may be useful to identify small focal high-grade CIN lesions, to distinguish some cases of CIN involving immature metaplastic squamous epithelium from immature metaplastic squamous epithelium not involved by CIN and to distinguish high-grade CIN from benign mimics. Most cervical carcinomas of squamous, glandular, and small cell type are p16-positive. In cervical glandular lesions, p16 is useful, as part of a panel, in the distinction between adenocarcinoma in situ (diffusely positive) and benign mimics, including tuboendometrial metaplasia and endometriosis, which are usually p16-negative or focally positive. p16 may be used, in combination with other markers, to distinguish between a cervical adenocarcinoma (diffuse positivity) and an endometrioid-type endometrial adenocarcinoma (negative or focally positive). Some uterine serous carcinomas are diffusely positive. In the vulva, p16 is positive in HPV-associated vulval intraepithelial neoplasia (VIN) but negative in VIN not associated with HPV. Similarly, HPV-associated invasive squamous carcinomas are p16-positive, whereas the more common non-HPV-associated neoplasms are largely negative or focally positive. In the uterus, p16 positivity is more common and widespread in leiomyosarcomas than leiomyomas, and this may be a useful aid to diagnosis, although problematic uterine smooth muscle neoplasms have not been extensively studied. Metastatic cervical adenocarcinomas in the ovary are usually diffusely p16-positive, and because these may closely mimic a primary ovarian endometrioid or mucinous adenocarcinoma, this may be a valuable diagnostic aid, although p16 expression in primary ovarian adenocarcinomas of these morphologic subtypes has not been widely investigated. Some ovarian serous carcinomas, similar to their uterine counterparts, are p16-positive.