Histologic grade, but not SYT-SSX fusion type, is an important prognostic factor in patients with synovial sarcoma: a multicenter, retrospective analysis.
OBJECTIVE
To assess the prognostic value of SYT-SSX fusion type, in comparison with other factors, in a population of 165 patients with synovial sarcoma (SS).


METHODS
Data on 165 patients with SS (141 with localized disease at diagnosis) were studied retrospectively. The following parameters were examined for their potential prognostic value: age at diagnosis, sex, tumor site (extremities v proximal/truncal), size, histology, mitotic count, necrosis, histologic grade (Federation Nationale des Centres de Lutte Contre le Cancer system), stage (1997 tumor-node-metastasis system classification), surgical margin status (assessed histologically), and fusion type (SYT-SSX1 v SYT-SSX2). Median follow-up time was 37 months (range, 2 to 302 months).


RESULTS
Among those patients with localized disease at diagnosis, median and 5-year disease-specific survivals (DSS) for the SYT-SSX1 and SYT-SSX2 subgroups were 126 months and 67.4% versus 82 months and 63.2%, respectively (P = .12). Median and 5-year metastasis-free survivals (MFS) were 84 months and 54.2% for SYT-SSX1 versus 50 months and 47.6% for SYT-SSX2 (P = .76). Univariate analyses showed that high histologic grade (grade 3), high mitotic count (>/= 10 mitoses/10 high-power fields), stage III disease, size greater than 7 cm, tumor necrosis, and presence of areas of poorly differentiated morphology were significant adverse prognostic factors for DSS and MFS, whereas SYT-SSX fusion type, tumor histology (biphasic v monophasic), and patient sex were not. Age greater than 35 years adversely affected DSS but not MFS. In multivariate analyses, histologic grade was the most significant prognostic factor for both DSS and MFS.


CONCLUSIONS
For patients with localized SS, histologic grade but not SYT-SSX fusion type is a strong predictor of survival.
Guillou
Louis
L
Institut Universitaire de Pathologie, rue du Bugnon 25, 1011 Lausanne, Suisse. louis.guillou@chuv.hospvd.ch
Benhattar
Jean
J
Bonichon
Françoise
F
Gallagher
Gabrielle
G
Terrier
Philippe
P
Stauffer
Edouard
E
Somerhausen
Nicolas de Saint Aubain
Nde S
Michels
Jean-Jacques
JJ
Jundt
Gernot
G
Vince
Dominique Ranchère
DR
Taylor
Sophia
S
Genevay
Muriel
M
Collin
Françoise
F
Trassard
Martine
M
Coindre
Jean-Michel
JM
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D014408:Biomarkers, Tumor / Q000032:analysis; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009362:Neoplasm Metastasis; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D013584:Sarcoma, Synovial / Q000175:diagnosis* / Q000473:pathology; D015996:Survival Rate
D014408:Biomarkers, Tumor; D015514:Oncogene Proteins, Fusion; C116512:SYT-SSX fusion protein