RELATIONSHIP BETWEEN TYPE-I COLLAGENASE ACTIVITY, INVASIVENESS AND METASTATIC POTENTIAL IN COLORECTAL-CARCINOMA

Background and methods - Less attention has been paid to type I collag enase in cancers than to type IV collagenase, although the role of the former in invasion may be important. We therefore determined type I c ollagenase activity of the advancing front of colorectal carcinoma and of normal mucosa. Results - Cancers showed higher activity than norma l mucosa. Cancers without liver or lymph node metastasis produced more enzyme than cancers with metastasis. The correlation of enzyme activi ty and vascular invasion was low, with no difference between cancers w ith and without vascular invasion. There was strong correlation betwee n enzyme activity and invasiveness, with small deep invading cancers h aving nearly twice the activity of large shallow invading cancers. Can cer cells secreting less enzyme require a longer time to invade and mi ght have greater opportunity to metastasize compared to cancers with h igh activity and the same depth of invasion. Conclusions - Our selecti on for cases with respect to depth of invasion indicated the misleadin g result that cancers producing less enzyme showed a high frequency of metastasis. However, these results did not indicate that cancers secr eting less enzyme have high metastatic potential. Type I collagenase w as shown to play an important role in invasiveness, and is thus sugges ted to be a useful index to assess malignant potential.