Dermatofibrosarcoma protuberans: clinical, pathological, and genetic (COL1A1-PDGFB ) study with therapeutic implications.
OBJECTIVE
To analyse the presence of collagen type I alpha 1-platelet-derived growth factor beta (COL1A1-PDGFB) transcripts in 20 cases of dermatofibrosarcoma protuberans (DFSP) and to assess the relationship between COL1A1 breakpoints and clinical and histopathological variables.


RESULTS
Multiplex reverse transcriptase-polymerase chain reaction was carried out using frozen tissue. Our series contained 14 men and six women. Histologically, most cases were of conventional type (n = 9), followed by fibrosarcoma (n = 4), Bednar tumour (n = 2), sclerosing (n = 2), myoid (n = 1) and atrophic (n = 1) DFSP, and giant cell fibroblastoma (n = 1). Immunohistochemistry revealed CD34 expression in 90% of cases. COL1A1-PDGFB fusion transcripts were present in 89% of cases (exons 18, 19, 20, 25, 26, 31, 33/34, 39, 40, 46, 47 and 48 of COL1A1 with exon 2 of PDGFB). There was no recurrence of DFSP in any of the 19 patients treated by Mohs surgery. A partial response was obtained in the two patients treated with imatinib.


CONCLUSIONS
The COL1A1-PDGFB fusion was present in all histological subtypes of DFSP, but not all cases expressed the fusion transcript. No association was observed between different COL1A1 breakpoints and clinicopathological parameters. Imatinib mesylate can be useful in locally advanced tumours and metastases.
Llombart
Beatriz
B
Department of Dermatology, University of Valencia, Valencia, Spain. beatriz.llombart@uv.es
Sanmartín
Onofre
O
López-Guerrero
Jose Antonio
JA
Monteagudo
Carlos
C
Serra
Carlos
C
Requena
Celia
C
Poveda
Andrés
A
Vistós
Juan Luis
JL
Almenar
Sergio
S
Llombart-Bosch
Antonio
A
Guillén
Carlos
C
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001483:Base Sequence; D001549:Benzamides; D024042:Collagen Type I / Q000235:genetics*; D000090602:Collagen Type I, alpha 1 Chain; D017931:DNA Primers / Q000235:genetics; D018223:Dermatofibrosarcoma / Q000235:genetics* / Q000473:pathology* / Q000628:therapy; D005260:Female; D050939:Gene Fusion; D020571:Genes, sis; D006801:Humans; D000068877:Imatinib Mesylate; D008297:Male; D008875:Middle Aged; D015580:Mohs Surgery; D010879:Piperazines / Q000627:therapeutic use; D011743:Pyrimidines / Q000627:therapeutic use; D012878:Skin Neoplasms / Q000235:genetics* / Q000473:pathology* / Q000628:therapy; D055815:Young Adult
D000970:Antineoplastic Agents; D001549:Benzamides; C000716127:COL1A1 protein, human; D024042:Collagen Type I; D000090602:Collagen Type I, alpha 1 Chain; D017931:DNA Primers; D010879:Piperazines; D011743:Pyrimidines; D000068877:Imatinib Mesylate