TITLE:
Case Report: Pazopanib Treatment Response in a Patient with Metastatic Pleomorphic Dermal Sarcoma (Atypical Fibroxanthoma) with Circulating Tumor Cell-Derived Colonies as a Predictive Marker
AUTHORS:
Wolfram E. Samlowski, Joseph Wojcik, Suzanne Samlowski, Douglas Fife, Todd Murry
KEYWORDS:
Atypical Fibroxanthoma, Pleomorphic Dermal Sarcoma, Vascular Endothelial Growth Factor Receptor, Targeted Therapy, Circulating Tumor Cells, Circulating Tumor Cell-Derived Cultures
JOURNAL NAME:
Journal of Cancer Therapy,
Vol.7 No.11,
October
31,
2016
ABSTRACT: Atypical
fibroxanthomas (AFX) are
rare skin tumors. These generally are superficial tumors, usually In the older literature, these have been termed
aggressive or metastatic AFX, but currently
these have been reclassified as pleomorphic dermal sarcomas (PDS) and systemic
undifferentiated pleomorphic sarcoma (UPS, formerly malignant fibrohistiocytic
sarcoma, MFH). We present the case of a 64-year old woman who developed a
deeply invasive PDS on the vertex of her scalp invading to the galea, with
in-transit scalp metastases. Very little information is available about optimal
treatment of metastatic PDS lesions. The patient was initially treated with 2
cycles of epirubicin/ifosfamide chemotherapy, resulting in
life-threatening complications. A pretreatment peripheral blood sample was sent
for CTC-derived colony assay. This sample grew 8 colonies from 10 ml blood. The
tumor failed to respond to epirubicin and ifosfamide, and after several months of hospitalization, a second peripheral
blood CTC-derived colony assay grew >376 colonies. The patient could
not tolerate additional chemotherapy. She was therefore
treated with the oral targeted agent pazopanib. The patient developed a dramatic biopsy-confirmed complete response. After 11 months of pazopanib treatment,
a repeat CTC-derived culture sample grew only 8 colonies/10 ml blood. The complete
response to pazopanib is still ongoing at over 41 months. To our knowledge, this is the first demonstration of clinical
complete response of a PDS tumor following targeted therapy. An additional novel feature was the demonstration that CTC-derived colonies could be grown from the blood of a PDS patient. The
number of colonies appeared to correlate with the clinical treatment response
and seemed to function as a potential prognostic marker.