Irradiation of myxoid/round cell liposarcoma induces volume reduction and lipoma-like morphology.
The aim of the study was to investigate the clinical and morphological effects of radiotherapy in the treatment of myxoid/round cell liposarcoma (MLS/RCLS). Thirty-three primary and metastatic MLS/RCLS tumours in 15 patients were treated with radiation therapy. Twenty-seven of the 33 tumours were surgically removed after preoperative radiation (34-46 Gy) while six tumours were treated with radiotherapy alone (44-60 Gy). The pretreatment diagnosis was established in all 15 patients based on fine needle aspirates or histological findings. Tumour size was measured by CT or MRI before and after radiotherapy in 30 tumours. Thirteen tumours from 11 patients were genetically characterised before and/or after radiation therapy. Twenty-three of 30 irradiated tumours showed a median reduction in tumour volume of 52% and seven lesions a median progression of 36%. All 27 surgically removed tumours revealed histological features of radiation response. The most striking morphological changes were lipoma-like appearance, paucicellularity and hyalinisation. Twelve of 13 tumours analysed before and/or after radiation therapy showed the FUS-DDIT3 translocation. Radiation therapy of MLS/RCLS induces histopathologic accumulation of mature lipoma-like areas and tumour volume reduction that may facilitate resectability.
Engström
Katarina
K
Department of Oncology, Sahlgrenska University Hospital, Göteborg, Sweden.
Bergh
Peter
P
Cederlund
Claes-Göran
CG
Hultborn
Ragnar
R
Willen
Helena
H
Aman
Pierre
P
Kindblom
Lars-Gunnar
LG
Meis-Kindblom
Jeanne M
JM
D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor; D044963:Biopsy, Fine-Needle; D018450:Disease Progression; D005260:Female; D006801:Humans; D018208:Liposarcoma, Myxoid / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care; D011446:Prospective Studies; D016896:Treatment Outcome
D014408:Biomarkers, Tumor