[469] New Prognostic Markers in Merkel Cell Carcinoma

Silvia Carnicero, M Carmen Gonzalez-Vela, Miguel A Piris. Hospital Universitario Marqués de Valdecilla, Santander, Spain

Background: Merkel cell carcinoma (MCC) is a highly aggressive neuroendocrine carcinoma of the skin that usually occurs on sun-exposed areas in elderly patients. The incidence of this rare tumor is increasing rapidly. The aim of this study was to identify prognostic markers of metastasis, using a panel of immunohistochemical markers recognizing oncogenic feaures of the neoplastic cells, as compared with classical clinicopathological criteria.
Design: Immunohistochemical analysis was performed using antibodies directed against p53, p63, VEGF, NM23 and Ki67 in a series of 33 cases of consecutively diagnosed MCC. Clinical date, follow-up and histopathologic parameters (size, mitoses, vascular invasion, lymphocytic infiltration, vascular invasion) were also evaluated. The significance of pathologic data and the expression of the different markers was evaluated using the chi-square test.
Results: A significant inverse correlation was found for NM23 expression in comparison with regional lymph node metastasis and /or hematogenous spread. A 75% of the cases negative for NM23 showed metastatic spreading while that 39% of the cases immunoreactive for nm23 showed metastasis. No association could be established between the NM23 expression and the tumor size, mitotic index, lymphocytic infiltration and angioinvasion. A statistically significant correlation between the immunoreactivity for VEGF and the metastasis tumor spread was found, with 8 of the 12 (66,6%) cases positive for VEGF showing lymph node or/and solid organ metastasis and only a 33,3% positive cases didn´t show metastasis. The only histopathologic parameter associated with metastatic potential was the tumor size.
Conclusions: Date from the current study indicate that VEGFR expression and loss of immunoreactivity for NM23 are associated with an increased risk of metastatic spread in MCC.
Category: Dermatopathology

Tuesday, March 20, 2012 9:30 AM

Poster Session III # 118, Tuesday Morning


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