This study investigated the incidence and routes of submandibular gland involvement in oral cavity carcinoma to determine the feasibility of submandibular gland sparing neck dissection.

The records of 155 patients diagnosed with oral cavity squamous cell carcinoma, with a total of 183 neck specimens, including those involving level I, were reviewed retrospectively.

Submandibular gland involvement, via direct invasion from the anatomical proximity of T4a tumours, was evident in two patients. The floor of mouth location, either primarily or as an extension of the primary tumour, was the only risk factor for submandibular gland involvement in oral cavity carcinoma (p = 0.042). Tumour location, clinical and pathological tumour (T) and nodal (N) stages, and radiological suspicion of mandible invasion, were not found to be statistically relevant (p > 0.05).

The results suggest the feasibility of preserving the submandibular gland in early stage oral cavity carcinoma unless the tumour is located in, or extends to, the floor of mouth.

To test the effect of dietary nutrients on oral precancerous lesions in a reverse-smoking (i.e. smoking with the glowing end inside the mouth) population in South India.

Case–control. Cases with precancerous lesions were matched to an equal number of lesion-free controls matched on age (±5 years), sex and village. All subjects used tobacco in some form. Dietary data were obtained using an interviewer-administered food-frequency questionnaire, designed for use in this population. All interviews were conducted blinded to the disease status of the subject. Data were analysed using logistic regression.

Nineteen rural villages in Srikakulam District, Andhra Pradesh.

From a survey of 6007 tobacco users, 485 (79% women) were found to have precancerous, mostly palatal, lesions (cases), and 487 lesion-free subjects were selected as controls.

All eligible subjects consented to participate and nearly all (>99%) had complete data for analyses. Reverse smoking was the most common form of tobacco use among cases (81.9%) and controls (73.5%), and reverse smokers were 5.19 times more likely than chewers to have these lesions (95% confidence interval = 1.35, 19.9). After controlling for relevant covariates, including the type of tobacco use, protective linear effects were observed for zinc (70% reduction across the interquartile range, P<<0.002 ), calcium (34% reduction, P<0.002 ), fibre (30% reduction, P<0.009 ), riboflavin (22% reduction, P<0.03 ) and iron (17% reduction, P<0.05 ).

Several dietary nutrients appear to protect against oral precancerous lesions that are strongly associated with reverse smoking. The results of this study indicate scope for targeting dietary factors in preventing oral cancer, which should be coupled with aggressive anti-tobacco use efforts.