[Distribution and expression of basement membrane proteins in malignant eyelid tumors and its clinical significance].

OBJECTIVE: To study the distribution and expression of type IV collagen (Col IV), laminin (LN) and fibronectin (FN) in the basement membrane of malignant eyelid tumors so as to explore the relationships between the basement membrane and the degree of differentiation, metastasis and prognosis of malignant tumors. METHODS: Eighty-five paraffin-embedded specimens of malignant eyelid tumors including basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and sebaceous cell carcinoma were studied to identify the Col IV, LN and FN with immunohistochemical SABC techniques. RESULTS: A continuous intact basement membrane (BM) could be identified in all of the normal tissues and benign tumor specimens. In the malignant tumor specimens, the BM was defective or absent. The positive expression rate of Col IV in BCC, SCC and sebaceous cell carcinoma was 65% (24/40), 56% (16/25) and 40% (8/20). The positive expression rate of LN was 58% (23/40), 40% (10/25) and 35.% (7/20), respectively. The positive expression rate of FN was 33% (13/40), 36% (9/25) and 30% (6/20), respectively. The positive expression rate of these extracellular matrices was correlated with the degree of differentiation of the tumor. The difference of positive rate between highly-differentiated and poorly-differentiated tumors was significant (P < 0.05). In a short term follow-up (6-18 months), a statistically significant correlation (P < 0.05) could be observed between tumor recurrence and BM integrity. A higher recurrence rate and early recurrence were found in patients with interrupted BM. CONCLUSION: The absence of expression of Col IV, LN and FN was related to the invasive capacity and recurrence of the tumor. This result can be used as an index for clinical judgment of prognosis of the eyelid tumors.