OBJECTIVEThe relationship between the mode of tumor invasion in the tumor-host borderline and the frequency of cervical lymph node metastasis was investigated in squamous cell carcinoma of the oral cavity.

METHODS200 cases with histologically proven squamous cell carcinoma of the oral cavity were studied by histological method with HE stained. The mode of invasion in the tumor-host relationship was classified into five grades by Yamamoto's criteria.

RESULTSWith regard to the relationship between the mode of invasion and metastasis, the more invasive the tumor tissue was, the more frequent the metastasis formed (P < 0.001). The frequency of metastasis in grades 1 and 2 was low (0 and 5.9%, respectively), The frequency of metastasis in grades 3 was moderate (14.3%), and that in grades 4c and 4d was highly rapid (63.0% and 82.9%, respectively). Single node metastases were frequent in grade 3 and grade 4c (66.7% and 58.8%, respectively), while plural node metastases were frequent in grade 4d (70.6%, P < 0.05). Moreover, the distribution of metastasized lymph nodes was focused on level 1 (41.2%) or level 1 and 2 (79.4%) in grade 4c and was dispersed from level 1 to 4 in grade 4d (P < 0.05). In the present study, the degree of differentiation did not correlate well with the frequency of metastasis.

CONCLUSIONThese results indicate that the more invasive the tumor cells were to the host, the more frequent the metastasis formed. The different mode of invasion would accompany with different frequency of metastasis, different number and distribution of metastasized lymph nodes.