Using tissue microarrays and cases from Tulane Medical Center and Medical College of Wisconsin, expression of smoothelin, DOG1, caldesmon, and p16 was evaluated by immunohistochemistry in 87 cases of LMS.
Compared with leiomyoma (LM), the figures for the strength of association were as follows: LM variants (RR = 1.53, 95%CI = 1.03-2.27, P = 0.036, random effect); leiomyosarcoma (LMS) (RR = 3.20, 95%CI = 1.68-6.12, P < 0.001, random effect); and smooth muscle tumors of uncertain malignant potential (STUMP) (RR = 2.90, 95%CI = 1.17-7.21, P = 0.022, random effect). p16INK4a expression was significantly higher in LMS than in LM variants (RR = 3.74, 95%CI = 1.96-7.13, P < 0.001, random effect) or STUMP (RR = 1.67, 95%CI = 1.26-2.23, P < 0.001, fixed effect).
Although p14 inactivation or overexpression of the human murine double minute homolog (HDM2) were frequent in LMS and UPS and could substitute for TP53 mutation or deletion, such alterations were rare in angiosarcomas.
A number of genes were found to be differentially expressed in these sample sets, and six genes including cyclin-dependent kinase inhibitor 2A, diaphanous (Drosophila homolog) 3, doublecortin, calpain 6, interleukin-17B, and proteolipid 1 were found to be overexpressed in LMS compared with normal myometrium and 18 other tissues.