Impact of Depth of Invasion (According to Layer) on Lymph Node Metastasis in Buccal Mucosa Cancers

(1) To study layer of invasion as predictor of cervical lymph node metastasis. (2) To decide a cut off depth according to layer of invasion for neck dissection. It is a prospective study with sample size of 220 patients at tertiary care hospital with previously untreated operable buccal mucosa carcinoma over period of 21 months. The factors considered under the study were Tumor layer of invasion, lymph node metastasis, Ultrasonography doppler neck, CT scan and gender. Wide excision of the lesion and reconstruction was done. Histopathological analysis of resected specimen were recorded as part of data collection for all the cases. Quantitative data represented using Mean +/- SD (Standard Deviation) and median and interquartile range compared using Chi square test. Standard principles of univariate analysis was used according to statistical methods. Depth when measured according to layer of invasion, was significantly associated with lymph node metastasis with 89% of the muscle as layer of invasion being Lymph node positive (p = 0.009). There is 1.39 times chances of lymph nodal metastasis in patients with muscle invasion as compared to submucosal invasion. Tumour layer of invasion plays important role in predicting chances of nodal metastasis in clinically N0 neck in buccal mucosa cancer. According to the study, we should electively proceed with ipsilateral lymph node dissection once the layer of tumour invasion is muscle. This study is limited by sample size and short duration of one year and nine months.