Expression of metalloproteinases endometrial stromal sarcoma: immunohistochemical study using image analysis

Aim-To investigate the expression of matrix metalloproteinases (MMP), a gro up of proteolytic enzymes with a central role in extracellular matrix invas ion and degradation, in stromal sarcomas. Methods-11 endometrial stromal sarcomas (four low grade tumours, seven high grade) were stained for MMP-2, MMP-3, and MMP-9 using immunohistochemical stains. The surgical material consisted of nine hysterectomy specimens and two pelvic recurrences. Three hysterectomy specimens, removed for leiomyoma s, were studied as controls. Staining area was evaluated using image analys is. Results-Age at the time of diagnosis ranged from 21 to 67 years. Four of th e 11 patients (three with high grade tumours and one with a low grade tumou r) died of the disease, six remained free of disease, and one was lost to f ollow up. Staining for MMP-2, MMP-3, and MMP-9 was more diffuse in high gra de tumours than in low grade tumours and controls. Staining for MMP-3 and M MP-9 was more pronounced in high grade than in low grade tumours (p = 0.04; p = 0,05), Staining for MMP-9 was significantly greater in all stromal sar comas than in controls (p < 0.001 for high grade tumours upsilon controls; p < 0.01 for law grade tumours upsilon controls). Diffuse staining for MMP- 2, exceeding 90% of the tumour area, was observed in three of seven high gr ade rumours but in no low grade tumours. There was no apparent correlation between staining for any of the three enzymes and survival. Conclusions-Both low and high grade endometrial stromal tumours express mat rix metalloproteinases. MMP3 and MMP-9 are expressed more diffusely in high grade than in low grade tumours. In the individual case, diffuse staining for MMP-2 appears to best characterise the high grade tumours. Thus stainin g for MMP-2, may aid in differentiating high grade from low grade tumours, and MMP-9 in differentiating normal endometrial stroma from low and high gr ade endometrial stromal sarcomas. MMP expression does not appear to predict disease outcome in endometrial stromal sarcoma.