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.
Jensen
V
V
Centre for Bone and Soft Tissue Sarcomas, University Hospital of Aarhus, Denmark.
Sørensen
F B
FB
Bentzen
S M
SM
Ladekarl
M
M
Nielsen
O S
OS
Keller
J
J
Jensen
O M
OM
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