EBV-negative lymphoepithelial-like carcinoma of the lower lip

Lymphoepithelial-like carcinoma (LEC) is a rare malignant neoplasm, which can be associated with Epstein-Barr virus (EBV) infection. Histologically, LEC is an undifferentiated carcinoma with an intermixed reactive lymphoplasmacytic infiltrate. LEC appears to be an uncommon tumor type of lip carcinoma. An 82-year-old white woman presented a lesion on her lower lip that developed over the last year. The lesion was characterized by ulceration with flat edges, hardened base, painful, and absence of regional lymphadenopathy. Microscopical analysis evidenced an intense inflammatory infiltrate, composed of lymphoplasmacytic cells, associated with scarce pleomorphic epithelial cells. Immunohistochemistry highlighted the LEC cells with strong expression of pan-CK AE1/AE3, EMA, p63, and p53. CD138 was also faintly positive. Ki-67 was >85%. In situ hybridization analysis did not show evidence of EBV. A diagnostic of EBV-negative LEC was made. We present an uncommon type of lip carcinoma, which can represent a diagnostic challenge for clinicians and pathologists

Cancer biomarker development from basic science to clinical practice

The amount of published literature on biomarkers has exponentially increased over the last two decades. Cancer biomarkers are molecules that are either part of tumour cells or secreted by tumour cells. Biomarkers can be used for diagnosing cancer (tumour versus normal and differentiation of subtypes), prognosticating patients (progression free survival and overall survival) and predicting response to therapy. However, very few biomarkers are currently used in clinical practice compared to the unprecedented discovery rate. Some of the examples are: carcino-embryonic antigen (CEA) for colon cancer; prostate specific antigen (PSA) for prostate; and estrogen receptor (ER), progesterone receptor (PR) and HER2 for breast cancer. Cancer biomarkers passes through a series of phases before they are used in clinical practice. First phase in biomarker development is identification of biomarkers which involve discovery, demonstration and qualification. This is followed by validation phase, which includes verification, prioritisation and initial validation. More large-scale and outcome-oriented validation studies expedite the clinical translation of biomarkers by providing a strong ‘evidence base’. The final phase in biomarker development is the routine clinical use of biomarker. In summary, careful identification of biomarkers and then validation in well-designed retrospective and prospective studies is a systematic strategy for developing clinically useful biomarkers

Investigating status of tumorigenic barriers in monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM)

Master'sMASTER OF SCIENC

Investigating various thresholds as immunohistochemistry cutoffs for observer agreement

Background: Clinical translation of immunohistochemistry (IHC) biomarkers requires reliable and reproducible cutoffs or thresholds for interpretation of immunostaining. Most IHC biomarker research focuses on the clinical relevance (diagnostic, prognostic, or predictive utility) of cutoffs, with less emphasis on observer agreement using these cutoffs. From the literature, we identified 3 commonly used cutoffs of 10% positive epithelial cells, 20% positive epithelial cells, and moderate to strong staining intensity (+2/+3 hereafter) to use for investigating observer agreement. Materials and Methods: A series of 36 images of microarray cores stained for 4 different IHC biomarkers, with variable staining intensity and percentage of positive cells, was used for investigating interobserver and intraobserver agreement. Seven pathologists scored the immunostaining in each image using the 3 cutoffs for positive and negative staining. Kappa ([kappa]) statistic was used to assess the strength of agreement for each cutoff. Results: The interobserver agreement between all 7 pathologists using the 3 cutoffs was reasonably good, with mean [kappa] scores of 0.64, 0.59, and 0.62, respectively, for 10%, 20%, and +2/+3 cutoffs. A good agreement was observed for experienced pathologists using the 10% cutoff, and their agreement was statistically higher than for junior pathologists (P=0.02). In addition, the mean intraobserver agreement for all 7 pathologists using the 3 cutoffs was reasonably good, with mean [kappa] scores of 0.71, 0.60, and 0.73, respectively, for 10%, 20%, and +2/+3 cutoffs. For all 3 cutoffs, a positive correlation was observed with perceived ease of interpretation (P<0.003). Finally, cytoplasmic-only staining achieved higher agreement using all 3 cutoffs than mixed staining patterns. Conclusions: All 3 cutoffs investigated achieve reasonable strength of agreement, modestly decreasing interobserver and intraobserver variability in IHC interpretation. These cutoffs have previously been used in cancer pathology, and this study provides evidence that these cutoffs can be reproducible between practicing pathologists

GENOMIC AND FUNCTIONAL CHARACTERIZATION OF THE P53 PATHWAY IN RELATION TO 17P13 (DEL) IN MULTIPLE MYELOMA

Ph.DDOCTOR OF PHILOSOPH

Biomarkers for pancreatic cancer: identification, validation and clinical application

Pancreatic cancer is common and aggressive: the main type is pancreatic ductal adenocarcinoma (PDAC). It is the fifth most common cause of cancer death in the UK with an overall five year survival of only 2-3%. Establishing the diagnosis of PDAC is important for optimal patient management but can be difficult and relies on imaging and cytology/pathology. Although imaging may be highly suggestive of PDAC, a pathological diagnosis is preferred prior to definitive treatment; therefore tissue samples are required. Cytology samples are obtained at endoscopy. Cytological analysis requires the identification of different cell types and in particular the distinction of malignant pancreatic epithelial cells from reactive pancreatic cells and other gastrointestinal contaminants. This requires experience and expertise and can be difficult. A tissue diagnosis is not achieved in a significant proportion of PDAC cases. Hence, an unmet clinical need exists for the diagnosis of PDAC from cytological samples. One potential way of improving the cytological diagnosis is to use immunohistochemistry (IHC) biomarkers as an adjunct to cytology in difficult to diagnose cases. Diagnostic IHC biomarkers have been investigated, but to date none has entered into routine clinical practice. The aim of this study was to improve the diagnosis of PDAC from cytology samples. It is hoped that the identification and validation of IHC biomarkers in PDAC will help their clinical translation. For biomarker identification a meta-analysis of potential IHC diagnostic biomarkers investigated in PDAC was performed. Sixteen biomarkers were quantified in meta-analysis and the highest ranked biomarkers were KOC, maspin, S100P, mesothelin and MUC1. These biomarkers have not entered into clinical practice partly because they were investigated in separate studies with relatively small sample sizes and without a uniform and clinically appropriate cut-off. Biomarkers identified in the meta-analysis were validated in a resection cohort from patients with pancreatico-biliary adenocarcinoma. The aim was to identify better biomarkers and cut-offs that could potentially be investigated in cytology samples. KOC, S100P, mesothelin and MUC1 were investigated in one set of tissue microarrays, while maspin was investigated in another set. Five cut-offs were carefully chosen for sensitivity/specificity analysis using receiver operating characteristics curve analysis. Using 20% positive cells as a cut-off achieved higher sensitivity/specificity values: KOC 84%/100%; S100P 83%/100%; mesothelin 88%/92%; MUC1 89%/63%; and Maspin 96%/99%. Analysis of a panel of KOC, S100P and mesothelin achieved almost 100% sensitivity and specificity if at least two biomarkers were positive for both 10% and 20% cut-offs. Clinical translation of biomarker requires a reliable and reproducible cut-off for interpretation of IHC. We identified three cut-offs for investigation to establish a consensus based cut-off(s) that could potentially be used by pathologists for PDAC and other cancers. A series of IHC images of microarray cores were used to investigate observer agreements for 10%, 20% and +2/+3 cut-offs. Seven pathologists participated in this study. The inter- and intra-observer agreements using the three cut-offs were reasonably good. For all three cut-offs a positive correlation was observed with perceived ease of interpretations (p<0.01 for all cut-offs). Finally, cytoplasmic only staining achieved higher agreement than cytoplasmic/nuclear and cytoplasmic/membranous staining. All three cut-offs investigated achieve reasonable strength of agreement modestly decreasing inter and intra-observer variability in IHC interpretation but 10% is slightly better than 20% and +2/+3 cut-offs. Finally, KOC, maspin, mesothelin and S100P were investigated in archival cytology samples with the aim to generate a diagnostic panel which could potentially help as an adjunct to cytology. Using 10% cut-off achieved higher sensitivity/specificity values: KOC 92%/100%; maspin 54%/100% and mesothelin 72%/100%. But no staining was observed for S100P. In addition, analysis of a panel of KOC, maspin and mesothelin achieved 82% sensitivity and 100% specificity for 10% cut-off if at least two biomarkers in the panel were positive. The inter-observer agreement for 10% positive cells as IHC cut-off in cytology samples was very good for all three biomarkers. In conclusion, a panel of KOC, maspin and mesothelin is a suitable diagnostic panel and 10% cut-off is a reasonable cut-off achieving high observer agreement. Their diagnostic accuracies approach those of optimal conventional cytology. These markers may be appropriate for further clinical validation and potentially routine use in difficult cases