E-cadherin expression is frequently reduced in infiltrative basal cell carcinoma

Expression of β-Catenin, E-Cadherin, and α-Smooth Muscle Actin in Basal Cell Carcinoma Before Photodynamic Therapy in Non-recurrent and Recurrent Tumors: Exploring the Ability of Predicting Photodynamic Therapy Outcome

Photodynamic therapy (PDT) is an effective and cosmetically beneficial treatment of low-risk basal cell carcinomas (BCCs). To optimize PDT response, it is important to correctly select tumors. We sought to find markers that could identify such tumors beyond contributions from clinical and histological examination. Studies have shown that β-catenin, E-cadherin, and α-smooth muscle actin (SMA) expression can indicate BCC aggressiveness/BCC invasiveness. We wanted to use these markers in an explorative study to investigate whether they were differently expressed among non-recurring compared with recurring BCCs, to evaluate their ability of predicting PDT outcome. Fifty-two BCCs were stained with antibodies against β-catenin, E-cadherin, and α-SMA, and evaluated using immunoreactive score (IRS), subcellular localization, and stromal protein expression. Results showed that IRS of E-cadherin was significantly different among recurring compared with non-recurring BCCs and with area under a receiver operating characteristic curve of 0.71 (95% confidence interval: 0.56-0.86, p=0.025). Stromal β-catenin expression significantly increased among recurring BCCs. Some recurring BCCs had intense expression in the deep invading tumor edge. In conclusion, E-cadherin, and stromal and deep edge β-catenin expression were most prominent in BCCs that recurred post-PDT, suggesting they could potentially predict PDT outcome. Further studies are needed to investigate whether these results are of clinical value.

Sebaceous Carcinoma of the Eyelid

BACKGROUND

Periocular sebaceous carcinoma (PSC) is a rare but aggressive neoplasm that tends to clinically and histopathologically mimic other conditions. PSC can be challenging to diagnose using histomorphology alone given its overlap with 2 more common tumors that occur in this area (basal cell carcinoma [BCC] and squamous cell carcinoma [SCC]). Use of immunohistochemistry can help resolve this differential diagnosis.

METHODS

A review of the literature was performed, focusing on the epidemiology, morphology, and immunohistochemical features of PSC.

RESULTS

The most useful immunostains in the differential diagnosis of PSC are epithelial membrane antigen, Ber-Ep4, androgen receptor (AR), and adipophilin. To discern PSC from BCC, one should use EMA, Ber-Ep4, AR, and adipophilin, whereas discerning PSC from SCC can be achieved by evaluating AR and adipophilin. In addition, p53 and ERBB2 (formally known as HER2/neu) are other potentially useful immunohistochemical markers for the differential diagnosis of PSC.

CONCLUSIONS

Use of new immunohistochemical techniques, as well as the elucidation of molecular alterations, such as the presence of ERBB2 amplification, will advance our understanding of PSC.

Gene Expression and Proteome Analysis as Sources of Biomarkers in Basal Cell Carcinoma

Basal cell carcinoma (BCC) is the world's leading skin cancer in terms of frequency at the moment and its incidence continues to rise each year, leading to profound negative psychosocial and economic consequences. UV exposure is the most important environmental factor in the development of BCC in genetically predisposed individuals, this being reflected by the anatomical distribution of lesions mainly on sun-exposed skin areas. Early diagnosis and prompt management are of crucial importance in order to prevent local tissue destruction and subsequent disfigurement. Although various noninvasive or minimal invasive techniques have demonstrated their utility in increasing diagnostic accuracy of BCC and progress has been made in its treatment options, recurrent, aggressive, and metastatic variants of BCC still pose significant challenge for the healthcare system. Analysis of gene expression and proteomic profiling of tumor cells and of tumoral microenvironment in various tissues strongly suggests that certain molecules involved in skin cancer pathogenic pathways might represent novel predictive and prognostic biomarkers in BCC.

Basal Cell Carcinoma Progression Correlates With Host Immune Response and Stromal Alterations: A Histologic Analysis

Neoplastic progression is characterized in part by escape from immune surveillance and formation of growth-permissive stroma. Basal cell carcinoma (BCC) can be subclassified into low- and high-risk types for local recurrence. To determine whether these types of BCC correlate with alterations in local host immune response and stroma and whether these changes follow stepwise histologic progression from low- to high-risk subtypes, we assessed the clinicopathologic features in 175 consecutive primary (nonrecurrent) BCC excision specimens. BCCs exhibited a significantly higher frequency of mixed rather than homogeneous growth patterns (76% vs. 24%, P=0.0001). Nodular (84%) was the most common pattern identified followed by superficial (77%), infiltrative (27%), morpheic (5%) and micronodular patterns (4%). Only superficial (12% of all BCC) and nodular (12%) patterns were identified in BCC with a homogeneous histologic phenotype. Micronodular and infiltrative-morpheic patterns were not identified together in mixed patterned BCCs, and these high-risk types were contiguous with nodular BCC. Superficial predominant BCC (major growth pattern) was significantly associated with trunk and extremity location (76%) and skin without solar elastosis (82%), whereas BCC harboring a nodular growth pattern component was significantly associated with a head and neck location (63%) and the presence of adjacent solar elastosis (all P< or =0.03). Significant correlations were identified for BCC subtypes with inflammatory and stromal alterations: superficial BCC with old regression and moderate to dense peritumoral lymphocytic infiltrates; high-risk types correlated with active regression; infiltrative and morpheic BCC with fibrosing tumor stroma; and micronodular BCC with loss of both host inflammatory and stromal tumor responses. Evaluating the theoretical histologic stepwise model of BCC progression (superficial-to-nodular-to-micronodular, or superficial-to-nodular-to-infiltrative-to-morpheic BCC types) revealed significant linear correlations with host response and alterations of tumor stroma (r=0.54, P=0.0001). BCC exhibit distinct epithelial-stromal-inflammatory patterns that correlate with BCC subtype and tumor progression. This ostensible pathway of diminishing host response and gain of permissive tissue environment highlights neoplastic evolution from low to high risk for local recurrence of BCC and implicates a histologic continuum reflecting dynamic host-BCC interactions.

Matrix metalloproteinases in tumor progression: focus on basal and squamous cell skin cancer

Many normal biological processes, such as reproduction, fetal development and wound healing, are critically dependent on controlled degradation of extracellular matrix (ECM) macromolecules. However, excessive degradation of matrix components occurs in pathologic tissue destruction, e.g. in atherosclerosis, rheumatoid arthritis, and cancer. Matrix metalloproteinases (MMPs) are degradative enzymes that play an important role in all aspects of tumor progression by enhancing tumor-induced angiogenesis and destroying local tissue architecture and basement membranes to allow tumor invasion and metastasis. Efficient breakdown of the ECM surrounding invasive cancer islands involves interplay between tumor cells, stromal cells, and inflammatory cells, all of which express a distinct set of MMPs. Besides the classical role of MMPs in degradation of ECM, MMPs may also indirectly influence the tumor microenvironment through the release of growth factors, cryptic sites or angiogenic factors, or through the generation of matrix fragments that inhibit tumor cell proliferation, migration and angiogenesis. This makes the contribution of MMPs to tumorigenesis much more complex than initially thought. Currently, a number of clinical studies have focused on testing MMP inhibitors as potential antineoplastic agents. In this review we discuss the present role of MMPs in the development and progression of cancer, focusing on non-melanoma skin cancers basal (BCC) and squamous (SCC) cell carcinoma, and the possible influence of MMPs in their differences.

Loss of T-cadherin (CDH13, H-cadherin) expression in cutaneous squamous cell carcinoma

We previously reported that T-cadherin (CDH13, H-cadherin), a unique cadherin molecule, was expressed on the basal cell layer in normal murine and human epidermis. In the present study, T-cadherin expression in archival human skin specimens comprising a spectrum of human squamous cell neoplasia was investigated. T-cadherin expression was observed in both normal epidermal basal cells and adnexal epithelial cells of formalin-fixed and paraffin-embedded tissue sections. Western immunoblotting also revealed that mature T-cadherin protein was expressed in cultured human skin tissue equivalent. Atypical keratinocytes in 27 of 53 specimens of actinic keratosis and 23 of 30 specimens of Bowen's disease expressed T-cadherin. In contrast, T-cadherin was focally expressed in 6 of 56 invasive cutaneous squamous cell carcinomas. To explore the molecular mechanism of down-regulation of T-cadherin expression in invasive squamous cell carcinoma, loss of heterozygosity, genetic alternations, and methylation status in the 5' region of the T-cadherin gene were investigated. Loss of heterozygosity at intron 1 of the T-cadherin gene was observed in 8 of 28 informative cases of invasive squamous cell carcinoma. Although no structural genomic alternations were found by sequence analysis, aberrant promoter methylation of the T-cadherin gene was found in 12 of 28 invasive squamous cell carcinomas. T-cadherin expression was restored in cultured A431 cells, in which aberrant methylation was found by treatment with the demethylating agent 5'-aza-2-deoxycytidine. These findings suggest that a combination of deletion and aberrant methylation of the T-cadherin gene may play a role in loss of gene expression in a considerable number of invasive cutaneous squamous cell carcinomas.