Association between nodal metastasis and histopathological factors in postoperative gingivo-buccal complex squamous cell carcinoma: A Retrospective Study.

OBJECTIVE: To evaluate association between histopathological factors and cervical lymph node metastasis in postoperative gingiva-buccal complex squamous cell carcinoma. METHODS: We retrospectively analyzed 98 postoperative gingiva buccal complex squamous cell carcinoma patients' clinical and histopathological findings. The variables assessed were age, sex, tumour site, tumour size, degree of differentiation (grade), depth of invasion (DOI), lymphovascular invasion (LVI), perineural invasion (PNI) and extracapsular extension (ECE) and their relation with nodal metastasis. RESULT: Out of 98 patients, 76 patients were pathologically node positive (pN+), including 39 of the 53 patients who were classified as cN0 (clinically node negative). The prevalence of occult neck metastasis was 73.5 %. Various parameters like tumour size, LVI, PNI, ECE and Grade showed statistically significant association with lymph node metastasis (p value: 0.029, 0.007, 0.003, 0.001 and 0.001 respectively) on bivariate analysis. Depth of invasion increases incidence of nodal metastasis but was not statistically significant (p value: 0.166). On multivariate logistic regression analysis male gender and presence of PNI were found as independent predicting factors for nodal metastasis (Odds Ratio 7.0826 to 8.65 respectively) while poorly differentiated carcinoma grade appeared non-inferior factor paradoxically (Odds Ratio 0.1033, overall 82.65 % cases were correctly classified by this model and area under ROC curve (AUC) was 0.794 of the model. CONCLUSION: Male gender, poorly differentiated carcinoma and presence of PNI were found as independent predicting factors for nodal metastasis. Male gender and PNI were found risk factors while poorly differentiated carcinoma grade appeared non-inferior factor (protective) paradoxical.