Expression of Laminin in Oral Squamous Cell Carcinomas

Abstract

Background and objectives: Laminin is a significant basement membrane (BM) glycoprotein, the expression of<br />which reflects BM integrity more precisely than do other ECM proteins. The present study aimed to evaluate laminin<br />expression in oral squamous cell carcinomas OSCC and to determine any associations with clinico-pathological<br />parameters (surgical margin status, lymph node involvement, survival and recurrence). Methods: Laminin expression was<br />evaluated in 31 cases of biopsy-proven OSCC by immunohistochemical staining and its association with prognosticators<br />and the Brynes grading system was determined by appropriate statistical analysis. Results: We observed a significant<br />increase in linear staining pattern (p<0.001) at the tumour-host interface in well-differentiated OSCC cases, in contrast<br />to poorly differentiated lesions which exhibited intense cytoplasmic expression within tumour cells. Higher cytoplasmic<br />laminin expression was seen in 33.3% of cases with involved surgical margins and 69.2% of cases with lymph node<br />metastasis (along with weak/absent staining of laminin around the tumour-host interface – Basement membrane around<br />tumour islands). Similarly, in 60% of the cases who died and in 81.8% of cases with tumour recurrence, moderately<br />intense cytoplasmic laminin expression was seen within tumour cells. On comparing variables of the Brynes grading<br />system, significant cytoplasmic expression of laminin was linked with mild inflammation (p<0.0016) and increased<br />mitotic activity (p<0.008). Conclusion: Based on these observations, immunohistochemical expression of laminin<br />might be useful to evaluate histological differentiation and aggressiveness of OSCCs.