Aim: This study was carried out in order to propose a model to predict regional lymph node metastasis of OSCC using histological parameters such as tumour stage, tumour size, pattern of invasion (POI), differentiation of tumour, and host immune response, together with the expression levels of six biomarkers (periostin, HIF-1α, MMP-9, β-catenin, VEGF-C, and EGFR), and, furthermore, to compare the impact of all these parameters on recurrence and 3 yr and 5 yr survival rates. Materials and Method. Histological materials collected from the archives were used to evaluate histological parameters and immunohistochemical profiles. Standard methods were used for immunohistochemistry and for evaluation of results. Data related to recurrence and survival (3 and 5 years) was also recorded. Clinical data was collected from patients' records.

Results: Male to female ratio was 3 : 1. The commonest site of OSCC was the buccal mucosa, and majority of them were T3 or T4 tumours presented at stage 4. 62.5% of the tumours were well differentiated. Three-year and 5-year survival rates were significantly associated with lymph node metastasis and recurrence. POI was significantly correlated with tumour size, stage, 3-year survival, EGFR, HIF-1α, periostin, and MMP-9 (p < 0.05). Expression of EGFR showed a direct association with metastasis (p < 0.05).

METHODS: Following a single day capacity building program on smokeless tobacco / areca nut control, two self-administered questionnaires were used to assess the improvement of knowledge and change of attitudes among 663 GDPs.

RESULTS: Majority had a good knowledge on harmful effects of SLT but not on areca nut. Knowledge of the current legislation on SLT control in Sri Lanka and carcinogenicity of areca nut was not satisfactory. Almost all agreed that proper counseling leads to patient quitting the habit, a formal training is necessary to conduct tobacco control activities and it should be a part of the regular treatment modalities. More than 80% of the participants support strict legislation. Most important factors leading to poor involvement in tobacco cessation activities were lack of expertise and inadequate educational material and not breach of patient privacy and lack of financial incentives. 20.1% dental surgeons had consumed smokeless tobacco / areca nut products in the past and only a few were current users of tobacco and/or areca nut.

METHODS: A nationwide online exercise was carried out to determine the influence of calibration on the reproducibility of the WHO 2017 and the binary OED grading systems.

RESULTS: A significant improvement was observed in the inter-observer agreement for the WHO 2017 OED grading system (K 0.196 vs. 0.448; Kw 0.357 vs. 0.562) after the calibration exercise. The significant difference (p = 0.027) in the level of agreement between those with five or more years and less than 5 years of experience was no more observed (p = 0.426) after the calibration exercise. The percent agreement for binary grading was significantly higher (91.8%) for buccal mucosal lesions as compared to lesions on the tongue after the calibration exercise.