No abstract

In patients with early head and neck squamous cell carcinoma (HNSCC), occult lymph node metastasis is difficult to predict by clinical or pathological parameters. However, such parameters are necessary to select patients either for elective neck dissection or the sentinel lymph node (SLN) procedure. The membrane glycoprotein podoplanin is normally expressed in lymphatic endothelial cells. Recently, expression of podoplanin by cancer cells was demonstrated to promote tumor cell motility and tumor lymphangiogenesis in vitro. The value of cancer cell-expressed podoplanin was to be determined as a predictive marker for SLN metastasis in early HNSCC of the oral cavity and oropharynx. One hundred twenty patients with HNSCC of the oral cavity and oropharynx undergoing a SLN biopsy were enrolled in this prospective clinical trial of SLN biopsy. Cancer cell-expressed podoplanin was determined by immunohistochemistry using tissue microarrays. Podoplanin expression was quantified by the intensity reactivity score and categorized into expression and nonexpression. SLN examination revealed occult metastasis in 45 patients (37.5%). Twenty-nine of 120 (24.2%) primary HNSCC showed podoplanin expression. Podoplanin expression correlated significantly with SLN metastasis (p 5 0.029) and remained a significant predictor for lymph node status even after controlling for tumor stage (p 5 0.028). As a predictive marker for SLN metastasis, however, podoplanin expression reached a sensitivity of a mere 36% and a specificity of 83%. Podoplanin expression is associated with metastasis to lymph nodes in vivo. Podoplanin immunohistochemistry in early HNSCC of the oral cavity and oropharynx may help to select patients for the SLN procedure and to identify patients with increased risk for presence of occult lymph node metastasis in the neck.Head and neck squamous cell carcinoma (HNSCC) is the fifth most common malignancy worldwide and responsible for more than 7,800 deaths per year in the United States alone. 1 Despite improvements in surgical treatment and radiation technology over the last decades, survival has not significantly improved. A chief feature of malignant behavior is the capability of tumor cells to metastasize to other organs. Metastasis of many human cancers, including HNSCC, occurs primarily through the lymphatic system. The cellular mechanisms responsible for the acquisition of a metastatic phenotype include the adaptation to potential hostile environment (blood stream, lymph nodes and organ of metastasis). In addition, the ''tumor cell-to-tumor cell'' and ''tumor cell-to-stromal environment'' cross talk is recognized as an important condition for invasion and metastasis.Very recently, expression of the 38-kDa Type 1 transmembrane glycoprotein podoplanin has been shown to induce tumor lymphangiogenesis and enhance metastasis to lymph nodes. 2,3 Human podoplanin is expressed in various normal human tissues. Podoplanin is highly and specifically expressed in lymphatic endothelial cells, but not in blood vessel endothelium. 4,5...

Anti-calretinin antibodies are useful to differentiate adenocarcinomas from malignant mesotheliomas of the lung. Therefore, calretinin expression is rarely reported for sarcomatoid mesotheliomas. Anti-podoplanin antibodies (eg D2-40) react with lymphatic endothelia, Kaposi's sarcoma, lymphangioma and mesotheliomas. For the interpretation of spindle cell lesions of the pleura, knowledge of calretinin and D2-40 expression frequencies in sarcomatoid mesothelioma is desirable. To systematically investigate the sensitivity of calretinin and D2-40 antibodies in epithelioid and sarcomatoid areas of malignant mesotheliomas, a tissue microarray with 341 malignant mesotheliomas, including 112 epithelioid, 46 sarcomatoid and 183 biphasic tumors was constructed. Epithelioid and sarcomatoid differentiated tumor areas were clearly separated within the tissue microarray. Expression of calretinin and D2-40 was separately studied in epithelioid and sarcomatoid areas by immunohistochemistry. Calretinin expression was found in 91% of epithelioid and 57% of sarcomatoid tumor areas. D2-40 immunostaining was present in 66% of the epithelioid and 30% of the sarcomatoid tumor areas. A combination of calretinin and D2-40 increased the sensitivity in epithelioid tumor areas to 0.96 and in sarcomatoid tumor areas to 0.66. These data indicate that a combination of calretinin and D2-40 will improve diagnostic accuracy for spindle cell lesions of the pleura, whereas almost all epithelioid mesotheliomas are identified by calretinin alone. Modern Pathology (2007) 20, 248-255.

Stem cell-like cells have recently been identified in melanoma cell lines, but their relevance for melanoma pathogenesis is controversial. To characterize the stem cell signature of melanoma, expression of stem cell markers BMI-1 and nestin was studied in 64 cutaneous melanomas, 165 melanoma metastases as well as 53 melanoma cell lines. Stem cell renewal factor BMI-1 is a transcriptional repressor of the Ink4a/Arf locus encoding p16 ink4a and p14Arf . Increased nuclear BMI-1 expression was detectable in 41 of 64 (64%) primary melanomas, 117 of 165 melanoma metastases (71%) and 15 of 53 (28%) melanoma cell lines. High nestin expression was observed in 14 of 56 primary melanomas (25%), 84 of 165 melanoma metastases (50%) and 21 of 53 melanoma cell lines (40%). There was a significant correlation between BMI-1 and nestin expression in cell lines (p 5 0.001) and metastases (p 5 0.02). These data indicate that cells in primary melanomas and their metastases may have stem cell properties. Cell lines obtained from melanoma metastases showed a significant higher BMI-1 expression compared to cell lines from primary melanoma (p 5 0.001). Further, primary melanoma lacking lymphatic metastases at presentation (pN0, n 5 40) was less frequently BMI-1 positive than melanomas presenting with lymphatic metastases (pN1; n 5 24; 52% versus 83%; p 5 0.01). Therefore, BMI-1 expression appears to induce a metastatic tendency. Because BMI-1 functions as a transcriptional repressor of the Ink4a/Arf locus, p16 ink4a and p14Arf expression was also analyzed. A high BMI-1/low p16 ink4a expression pattern was a significant predictor of metastasis by means of logistic regression analysis (p 5 0.005). This suggests that BMI-1 mediated repression of p16 ink4a may contribute to an increased aggressive behavior of stem cell-like melanoma cells. ' 2007 Wiley-Liss, Inc.

Several reports have shown that a long delay between cutting sections and immunohistochemical (IHC) staining can decrease the IHC reaction intensity. However, systematic large-scale studies to investigate to what extent this problem may influence the outcome of translational research studies are lacking. In this study, we used a tissue microarray (TMA) approach to investigate the influence of slide age on comparisons between the results of IHC analyses for estrogen receptor (ER), progesterone receptor (PR), cyclin D1, HER2 (HercepTest), and E-cadherin and clinical outcome in a series of 522 breast cancer patients. Old TMA sections stored for 6 months at 41C and freshly cut sections were analyzed under exactly identical experimental conditions. As compared to results obtained on freshly cut sections, the frequency of positivity on old sections decreased from 65 to 46% for ER (Po0.0001), from 33 to 18.5% for PR (Po0.0001), from 16.3 to 9.6% for HER2 (P ¼ 0.0047), from 45.1 to 37.7% for cyclin D1 (P ¼ 0.10), and from 58.9 to 32.9% for E-cadherin (Po0.0001). Despite the lower fraction of positive cases, most associations between IHC data and tumor phenotype that were observed in fresh section analysis were also found when old section data were analyzed. The results confirm that slide aging has a great influence on the intensity of IHC staining in individual cases, but they also suggest that many clinicopathological associations can be detected if suboptimally processed sections are used for IHC.