2005 Volume 50 Issue 1 Pages 39-43
In this report, we describe a case of recurrent desmoid tumor that was characterized by a novel APC gene mutation and osteopontin (OPN) expression. A 20-year-old female patient with adenomatous polyposis underwent a right colectomy at 13 years of age. Five years later, she developed an abdominal desmoid tumor that was resected. After 2 more years, a recurrent desmoid tumor was found in the same region. This tumor grew rapidly and quickly became massive. The doubling time was estimated to be 122 days, based on the computed tomography findings. When we analyzed the APC gene in the recurrent desmoid tumor, we found a novel frame-shift mutation at codon 1564. This frame-shift mutation changed TTA to TAG, which is a stop codon. Northern blot analysis and immunohistochemical analysis for OPN, a GRGDS (glycine-arginine-glycine-aspartic acid-serine)- containing adhesive molecule, revealed abundant amounts of OPN mRNA and protein expression in this desmoid tumor. We postulated that the truncated APC protein and OPN expression might be involved in the invasive nature of this recurrent desmoid tumor. A primary cell culture derived from the desmoid tumor was assessed for chemosensitivity to 5-fluorouracil, cisplatin, doxorubicin, colchicine, docetaxel, and anti-OPN antibody. Docetaxel was found to have the strongest inhibitory effect on cell growth. As a result, docetaxel was administered to this patient (60 mg/m2/month) for 3 cycles. Over the next 2 years, no detectable recurrences occurred. Thus, docetaxel was clinically effective for the treatment of a recurrent desmoid tumor.
