p63 Expression in Merkel Cell Carcinoma Is Related to Prognosis: An Immunohistochemical and Molecular Analysis

Background: p63 expression in Merkel cell carcinoma (MCC) indicates an aggressive behavior of the tumor. At least three TA variants (TAp63\u3b1,\u3b2,\u3b3) and three \u394N variants (\u394Np63\u3b1,\u3b2,\u3b3) by alternative splicing from p63 gene have been identified. In addition recently it has been suggested that presence of polyomavirus (MCPyV) in MCC tumor tissue is an indicator of adverse prognosis. Therefore, to better define the role of p63 and its variants in MCC and the possible relation to MCPyV, we examined a series of MCC from one single institution. Design: 18 cases of MCC from 15 patients (2 cases showed nodal metastases and 1 case brain metastasis) were investigated for p63 expression by immunohistochemistry (IHC) and by reverse-transcription polymerase chain reaction (RT-PCR) using isoform-specific primers to evaluate the p63 mRNA expression patterns. Probes for p63 gene (3q28) were used for FISH analysis to evaluate the p63 gene status. The presence of MCPyV in the MCC tumor genome was also investigated by PCR in all cases. Results: p63 expression was detected in 11/18 (61%) cases using IHC and p63 positivity was associated with decreasing overall survival (p=0.003). All these 11 cases presented at least one of the p63 isoforms, both in the primary MCC (8 cases) and in metastases (3 cases), with a variable expression pattern of the isoforms: TAp63\u3b1 was detected in 7/11 cases, \u394Np63\u3b2 in 3/11 cases and \u394Np63\u3b1 in 1/11 case. No p63 gene amplification was found by FISH analysis. All these patients died of disease after average follow-up of 31 months (range: 2-142 months). The remaining 7 cases of MCC, showing negativity for p63 at IHC, did not display any p63 isoform in 5 cases while 2 cases showed only \u394Np63 isoforms with different C-terminals (\u3b1 and \u3b3, respectively). Four of the patients are alive without disease, 2 died of other causes and one is alive with nodal metastasis. The average follow-up was 42 months (range: 8-67 months). Clonal integration of MCPyV DNA sequences was observed in all cases. Conclusions: The present IHC and molecular data confirm p63 expression in a group of MCC with aggressive clinical behavior and suggest that a transcriptional dysregulation of p63 gene is involved in the pathogenesis of MCC. IHC analysis is less sensitive than the molecular analysis to value p63 expression in MCC cases. Clonal integration of MCPyV DNA sequences does not seem related to prognosis

p63 Expression in Merkel Cell Carcinoma Is Related to Prognosis: An Immunohistochemical and Molecular Analysis

Background: p63 expression in Merkel cell carcinoma (MCC) indicates an aggressive behavior of the tumor. At least three TA variants (TAp63\u3b1,\u3b2,\u3b3) and three \u394N variants (\u394Np63\u3b1,\u3b2,\u3b3) by alternative splicing from p63 gene have been identified. In addition recently it has been suggested that presence of polyomavirus (MCPyV) in MCC tumor tissue is an indicator of adverse prognosis. Therefore, to better define the role of p63 and its variants in MCC and the possible relation to MCPyV, we examined a series of MCC from one single institution. Design: 18 cases of MCC from 15 patients (2 cases showed nodal metastases and 1 case brain metastasis) were investigated for p63 expression by immunohistochemistry (IHC) and by reverse-transcription polymerase chain reaction (RT-PCR) using isoform-specific primers to evaluate the p63 mRNA expression patterns. Probes for p63 gene (3q28) were used for FISH analysis to evaluate the p63 gene status. The presence of MCPyV in the MCC tumor genome was also investigated by PCR in all cases. Results: p63 expression was detected in 11/18 (61%) cases using IHC and p63 positivity was associated with decreasing overall survival (p=0.003). All these 11 cases presented at least one of the p63 isoforms, both in the primary MCC (8 cases) and in metastases (3 cases), with a variable expression pattern of the isoforms: TAp63\u3b1 was detected in 7/11 cases, \u394Np63\u3b2 in 3/11 cases and \u394Np63\u3b1 in 1/11 case. No p63 gene amplification was found by FISH analysis. All these patients died of disease after average follow-up of 31 months (range: 2-142 months). The remaining 7 cases of MCC, showing negativity for p63 at IHC, did not display any p63 isoform in 5 cases while 2 cases showed only \u394Np63 isoforms with different C-terminals (\u3b1 and \u3b3, respectively). Four of the patients are alive without disease, 2 died of other causes and one is alive with nodal metastasis. The average follow-up was 42 months (range: 8-67 months). Clonal integration of MCPyV DNA sequences was observed in all cases. Conclusions: The present IHC and molecular data confirm p63 expression in a group of MCC with aggressive clinical behavior and suggest that a transcriptional dysregulation of p63 gene is involved in the pathogenesis of MCC. IHC analysis is less sensitive than the molecular analysis to value p63 expression in MCC cases. Clonal integration of MCPyV DNA sequences does not seem related to prognosis

Expression of p63 is the sole independent marker of aggressiveness in localised (stage I-II) Merkel cell carcinomas

Merkel cell carcinoma of the skin is a malignant neuroendocrine tumour, whose prognostic criteria are a matter of dispute. Specifically, no predictor is presently available in stage I\u2013II tumours. We collected clinical and follow-up data from 70 Merkel cell carcinomas of the skin. The same cases were studied for p63 expression by immunohistochemistry, by reverse-transcription PCR (RT-PCR) and TP63 gene status by FISH and for presence of Merkel cell polyomavirus by PCR. Stage emerged as a significant prognostic parameter (P\ubc0.008). p63 expression, detected in 61% (43/70) of cases by immunohistochemistry, was associated with both decreased overall survival (Po0.0001) and disease-free survival (Po0.0001). Variable expression patterns of the different p63 isoforms were found only in cases immunoreactive for p63. In these latter lesions, at least one of the N-terminal p63 isoforms was detected and TAp63a was the most frequently expressed isoform. TP63 gene amplification was observed by FISH in only one case. Presence of Merkel cell polyomavirus DNA sequences was detected in 86% (60/70) of Merkel cell carcinomas and did not emerge as a significant prognostic parameter. Merkel cell carcinoma cases at low stage (stage I-II) represented over half (40/70 cases, 57%) of cases, and the clinical course was uneventful in 25 of 40 cases while 15 cases died of tumour (10/40 cases) within 34 months or were alive with disease (5/40 cases) within 20 months. Interestingly, a very strict correlation was found between evolution and p63 expression (Po0.0001). The present data indicate that p63 expression is associated with a worse prognosis in patients with Merkel cell carcinoma, and in localised tumours it represents the single independent predictor of clinical evolution

Expression of P63 in merkel cell carcinoma is related to prognosis: an immunohistochemical and molecular analysis

Background. p63 expression in Merkel cell carcinoma (MCC) indicates an aggressive behaviour of the tumour. At least three TA variants (TAp63\u3b1,\u3b2,\u3b3) and three \u394N variants (\u394Np63\u3b1,\u3b2,\u3b3) by alternative splicing from p63 gene have been identified. Recently it has been suggested that presence of polyomavirus (MCPyV) in MCC tumour tissue is an indicator of adverse prognosis. To better define the role of p63 and its variants in MCC and the possible relation to MCPyV, we examined a series of MCC from 45 patients collected from different Institutions. Methods. 50 cases of MCC from 45 patients (6 cases showed nodal metastases and 1 case brain metastasis) were investigated for p63 expression by immunohistochemistry (IHC) and by reverse- transcription polymerase chain reaction (RT-PCR) using isoform-specific primers to evaluate the p63 mRNA expression patterns. Probes for p63 gene (3q28) were used for FISH analysis to value the p63 gene status. The presence of MCPyV in the MCC tumour genome was also investigated by PCR in all cases. Results. p63 expression was detected in 62% of cases by IHC and it was associated with decreasing overall survival (p = 0.003). All these cases but one presented at least one of the p63 isoforms by RT-PCR, both in the primary MCC (25 cases) and in metastases (5 cases), with a variable expression pattern of the isoforms (TAp63\u3b3 was present in 76.7% of cases, \u394Np63\u3b2 in 16.7%, \u394Np63\u3b1 in 36.7%, TAp63\u3b2 in 16.7%, TAp63\u3b3 in 6.7%, \u394Np63\u3b3 in 3.3%). P63 gene gain was found by FISH analysis in only one case. Clonal integration of MCV DNA sequences was observed in 86.6% of cases. The present IHC and molecular data confirm p63 expression in a group of MCC with aggressive clinical behaviour and suggest that a transcriptional dysregulation of p63 gene is involved in the pathogenesis of MCC. IHC analysis is less specific than the molecular analysis to value p63 expression in MCC. Clonal integration of MCPyV DNA sequences does not seem related to prognosis

Cytogenetic and molecular evaluation of 241 small supernumerary marker chromosomes: cooperative study of 19 Italian laboratories

PURPOSE: We evaluated the experiences of 19 Italian laboratories concerning 241 small supernumerary marker chromosomes (sSMCs) with the aim of answering questions arising from their origin from any chromosome, their variable size and genetic content, and their impact on the carrier's phenotype. METHODS: Conventional protocols were used to set up the cultures and chromosome preparations. Both commercial and homemade probes were used for the fluorescent in situ hybridization analyses. RESULTS: A total of 113 of the 241 sSMCs were detected antenatally, and 128 were detected postnatally. There were 52 inherited and 172 de novo cases. Abnormal phenotype was present in 137 cases (57%), 38 of which were antenatally diagnosed. A mosaic condition was observed in 87 cases (36%). In terms of morphology, monocentric and dicentric bisatellited marker chromosomes were the most common, followed by monocentric rings and short-arm isochromosomes. The chromosomes generating the sSMCs were acrocentric in 132 cases (69%) and non-acrocentric chromosomes in 60 cases (31%); a neocentromere was hypothesized in three cases involving chromosomes 6, 8, and 15. CONCLUSION: The presented and published data still do not allow any definite conclusions to be drawn concerning karyotype-phenotype correlations. Only concerted efforts to characterize molecularly the sSMCs associated or not with a clinical phenotype can yield results suitable for addressing karyotype-phenotype correlations in support of genetic counseling

Cytogenetic and molecular evaluation of 241 small supernumerary marker chromosomes: Cooperative study of 19 Italian laboratories

PURPOSE: We evaluated the experiences of 19 Italian laboratories concerning 241 small supernumerary marker chromosomes (sSMCs) with the aim of answering questions arising from their origin from any chromosome, their variable size and genetic content, and their impact on the carrier's phenotype. METHODS: Conventional protocols were used to set up the cultures and chromosome preparations. Both commercial and homemade probes were used for the fluorescent in situ hybridization analyses. RESULTS: A total of 113 of the 241 sSMCs were detected antenatally, and 128 were detected postnatally. There were 52 inherited and 172 de novo cases. Abnormal phenotype was present in 137 cases (57%), 38 of which were antenatally diagnosed. A mosaic condition was observed in 87 cases (36%). In terms of morphology, monocentric and dicentric bisatellited marker chromosomes were the most common, followed by monocentric rings and short-arm isochromosomes. The chromosomes generating the sSMCs were acrocentric in 132 cases (69%) and non-acrocentric chromosomes in 60 cases (31%); a neocentromere was hypothesized in three cases involving chromosomes 6, 8, and 15. CONCLUSION: The presented and published data still do not allow any definite conclusions to be drawn concerning karyotype-phenotype correlations. Only concerted efforts to characterize molecularly the sSMCs associated or not with a clinical phenotype can yield results suitable for addressing karyotype-phenotype correlations in support of genetic counseling