ABSTRACT Introduction: Recent advances in the field of head and neck cancer have identified depth of invasion (DOI) and worst pattern of invasion (WPOI) as important prognostic/predictive factors in oral cancers. Muscle invasion, which has a better reproducibility, can be a suitable alternative as a predictor of biological behavior, especially if combined with WPOI. There is sparse literature available regarding its prognostic significance. Materials and Methods: We analyzed 35 cases of oral-squamous-carcinomas, where the presence or absence of muscle invasion was correlated with other prognostic factors, with respect to nodal positivity and advanced stage. Result: The positive predictive values (PPV) of DOI, WPOI, and muscle invasion in relation to lymph node metastasis were 42.3%, 64.7%, and 47.8%, respectively. The PPVs of DOI, WPOI, and muscle invasion in relation to stage were 57.7%, 70.6%, and 65.22%, respectively. The negative predictive values (NPV) of DOI, WPOI, and muscle invasion in relation to nodal metastasis were 88.89%, 94.44%, and 91.66%, respectively. The NPVs of DOI, WPOI, and muscle invasion in relation to tumor stage were 66.67%, 66.67%, and 75%, respectively. PPV of muscle invasion was higher than that of DOI. WPOI and muscle invasion were combined and correlated with nodal positivity/high clinical staging. The PPV (71.42% and 85.71%) was significantly greater than these parameters alone and was more significant than DOI. The NPVs (90.47% and 76.19%) were also significantly higher. Conclusion: WPOI along with muscle invasion in squamous cell carcinoma could be a supplement to DOI in predicting lymph nodal metastasis and tumor stage.
Mukherjee et al. (Wed,) studied this question.