Immunohistologic distribution of basement membrane in oral squamous cell carcinoma.

The distribution pattern of the basement membrane (BM) around tumor cells was determined in 72 oral squamous cell carcinomas by immunohistochemical staining with antibodies against human type IV collagen, laminin, and heparan sulfate proteoglycan. An intact continuous BM was found in 29 cases, whereas partial or widespread loss of the BM was detected in the other 43 cases (59.7%). Statistical analysis showed that the degree of BM loss was correlated with the degree of differentiation of tumor cells, but not with tumor size, and, most significantly, with the mode of cancer invasion and the incidence of lymph node metastasis. Carcinoma with a well-defined tumor-stromal boundary generally expressed an intact continuous BM. In contrast, the majority of diffusely invasive carcinomas lacked a continuous BM. Carcinomas with a widespread loss of BM structures showed a high frequency of regional lymph node metastasis (16 of 18 cases, 88.9%).