PT - JOURNAL ARTICLE AU - SHALINI TAYAL AU - ELIZABETH CLASSEN AU - LYNNE BEMIS AU - WILLIAM A. ROBINSON TI - c-kit Expression in Dedifferentiated and Well-differentiated Liposarcomas; Immunohistochemistry and Genetic Analysis DP - 2005 May 01 TA - Anticancer Research PG - 2215--2220 VI - 25 IP - 3B 4099 - http://ar.iiarjournals.org/content/25/3B/2215.short 4100 - http://ar.iiarjournals.org/content/25/3B/2215.full SO - Anticancer Res2005 May 01; 25 AB - Background: c-kit expression by immunohistochemistry has been utilized to identify cancer patients who can be treated with imatinib-mesylate. In gastrointestinal stromal tumors (GISTs), an activating mutation in c-kit predicts treatment response; its presence in other soft tissue tumors is unexplored. Materials and Methods: We evaluated seven cases of dedifferentiated liposarcomas (DDLS) and compared those with seven well-differentiated liposarcomas (WDLS). Immunohistochemical staining for c-kit was performed using a polyclonal antibody. Using PCR, exons 9, 10-11, 12-13 and 17 of c-kit were amplified and direct DNA sequencing performed. Results: Two out of 7 (30%) DDLS showed focal weak immunoreactivity with c-kit; no (0%) WDLS stained with c-kit. Seven out of 7 (100%) DDLS showed an allelic variation in exon 10, with a single base pair substitution (A>C) at codon 541; 3/7 (43%) WDLS showed the same change. Conclusion: c-kit immunoreactivity did not correlate with the change in DNA sequence; DDLS showed a consistent allelic variation in c-kit that may have significant prognostic, diagnostic and therapeutic implications. Copyright© 2005 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved