Proliferative activity (MIB-1 index) is an independent prognostic parameter in patients with high-grade soft tissue sarcomas of subtypes other than malignant fibrous histiocytomas: a retrospective immunohistological study including 216 soft tissue sarcomas.
OBJECTIVE
To evaluate the prognostic value of tumour proliferative activity, p53 accumulation and bcl-2 expression in a retrospective series of 216 patients with soft tissue sarcomas (STS).


RESULTS
The immunohistochemical analyses were performed on formalin-fixed, paraffin-embedded tissue. The proliferative activity was assessed by use of the monoclonal antibody MIB-1 and evaluated in multiple, random systematic sampled fields of vision. The percentage of proliferating cells (the MIB-1 index) ranged between 1% and 85% (median 12%). A significant increase in mean MIB-1 index was seen with increasing histological malignancy grade. Variation in the incidence of p53 accumulation and bcl-2 positivity among different histological subtypes was observed. p53 accumulation was frequent in synovial sarcomas and leiomyo- and rhabdomyosarcomas, whereas bcl-2 preferentially was expressed in synovial sarcomas. Univariate analysis identified patient age, tumour size, histological grade of malignancy, MIB-1 index and p53 accumulation as significant prognostic parameters. Multivariate Cox analysis, including tests for interaction terms between histological subtypes and MIB-1 index, showed independent prognostic effect of MIB-1 index and tumour size in patients with high-grade tumours of other subtypes than malignant fibrous histiocytoma (MFH).


CONCLUSIONS
Histopathological malignancy grading is the most important single prognostic factor for overall survival in STS, but estimation of MIB-1 index is useful for identifying the least favourable subgroup of high grade STS of other subtypes than MFH, for whom adjuvant therapy may be indicated.
Centre for Bone and Soft Tissue Sarcomas, University Hospital of Aarhus, Denmark.
V
V
Jensen
F B
FB
Sørensen
S M
SM
Bentzen
M
M
Ladekarl
O S
OS
Nielsen
J
J
Keller
O M
OM
Jensen
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D034961:Antigens, Nuclear; D002455:Cell Division; D002648:Child; D002675:Child, Preschool; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D019394:Ki-67 Antigen; D008875:Middle Aged; D009687:Nuclear Proteins / Q000032:analysis; D011379:Prognosis; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis; D012189:Retrospective Studies; D012509:Sarcoma / Q000737:chemistry / Q000175:diagnosis / Q000401:mortality / Q000473:pathology*; D012983:Soft Tissue Neoplasms / Q000737:chemistry / Q000175:diagnosis / Q000401:mortality / Q000473:pathology*; D015996:Survival Rate; D016159:Tumor Suppressor Protein p53 / Q000032:analysis
D034961:Antigens, Nuclear; D019394:Ki-67 Antigen; D009687:Nuclear Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53