TY - JOUR
T1 - C-KIT expression in primary and metastatic merkel cell carcinoma
AU - Feinmesser, Meora
AU - Halpern, Marisa
AU - Kaganovsky, Ella
AU - Brenner, Baruch
AU - Fenig, Eyal
AU - Hodak, Emmilia
AU - Sulkes, Jaqueline
AU - Okon, Elimelech
PY - 2004/12
Y1 - 2004/12
N2 - Merkel cell carcinoma (MCC) is an aggressive neuroendocrine tumor of the skin that is associated with a high incidence of recurrence and metastasis. The therapeutic arsenal for this malignancy is limited and once it spreads, there is no effective treatment, c-kit expression has been demonstrated previously in primary MCCs thus raising the possibility of treating MCCs with imatinib mesylate, the tyrosine kinase inhibitor that has shown promise in the management of c-kit expressing tumors. In this study we examine 25 additional primary MCCs and also 6 of their lymph node metastases. Formalin-fixed, paraffin-embedded tissues were stained immunohistochemically with an antibody directed against the KIT receptor. Percentage and intensity of staining were analyzed semiquantitatively using a three-tiered system. Twenty-one of the 25 (84%) primary tumors stained positively for KIT, of which 14 (67%) showed widespread positivity. Five of the 6 lymph nodes (83%) were similarly positive. High mitotic rate and vascular invasion in the primary tumors tended to be associated with prominent staining in the lymph node metastases. No association was found between c-kit expression and outcome. We confirm that the majority of primary MCCs express c-kit and further find that metastases are positive for the KIT receptor as well. Thus, c-kit expression may be an early event in the transformation of MCC, but not a marker for tumor progression.
AB - Merkel cell carcinoma (MCC) is an aggressive neuroendocrine tumor of the skin that is associated with a high incidence of recurrence and metastasis. The therapeutic arsenal for this malignancy is limited and once it spreads, there is no effective treatment, c-kit expression has been demonstrated previously in primary MCCs thus raising the possibility of treating MCCs with imatinib mesylate, the tyrosine kinase inhibitor that has shown promise in the management of c-kit expressing tumors. In this study we examine 25 additional primary MCCs and also 6 of their lymph node metastases. Formalin-fixed, paraffin-embedded tissues were stained immunohistochemically with an antibody directed against the KIT receptor. Percentage and intensity of staining were analyzed semiquantitatively using a three-tiered system. Twenty-one of the 25 (84%) primary tumors stained positively for KIT, of which 14 (67%) showed widespread positivity. Five of the 6 lymph nodes (83%) were similarly positive. High mitotic rate and vascular invasion in the primary tumors tended to be associated with prominent staining in the lymph node metastases. No association was found between c-kit expression and outcome. We confirm that the majority of primary MCCs express c-kit and further find that metastases are positive for the KIT receptor as well. Thus, c-kit expression may be an early event in the transformation of MCC, but not a marker for tumor progression.
KW - Merkel cell carcinoma
KW - Tyrosine kinase inhibitors
KW - c-kit
UR - http://www.scopus.com/inward/record.url?scp=11444262478&partnerID=8YFLogxK
U2 - 10.1097/00000372-200412000-00003
DO - 10.1097/00000372-200412000-00003
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C2 - 15618926
AN - SCOPUS:11444262478
SN - 0193-1091
VL - 26
SP - 458
EP - 462
JO - American Journal of Dermatopathology
JF - American Journal of Dermatopathology
IS - 6
ER -