Distribution and Frequency of Salivary Gland Tumours: An International Multicenter Study.

BACKGROUND: Salivary gland tumours (SGT) are a relatively rare group of neoplasms with a wide range of histopathological appearance and clinical features. To date, most of the epidemiological studies on salivary gland tumours are limited for a variety of reason including being out of date, extrapolated from either a single centre or country studies, or investigating either major or minor glands only. METHODS: This study aimed to mitigate these shortcomings by analysing epidemiological data including demographic, anatomical location and histological diagnoses of SGT from multiple centres across the world. The analysed data included age, gender, location and histological diagnosis from fifteen centres covering the majority of the world health organisation (WHO) geographical regions between 2006 and 2019. RESULTS: A total of 5739 cases were analysed including 65% benign and 35% malignant tumours. A slight female predilection (54%) and peak incidence between the fourth and seventh decade for both benign and malignant tumours was observed. The majority (68%) of the SGT presented in major and 32% in the minor glands. The parotid gland was the most common location (70%) for benign and minor glands (47%) for malignant tumours. Pleomorphic adenoma (70%), and Warthin's tumour (17%), were the most common benign tumours whereas mucoepidermoid carcinoma (26%) and adenoid cystic carcinoma (17%) were the most frequent malignant tumours. CONCLUSIONS: This multicentre investigation presents the largest cohort study to date analysing salivary gland tumour data from tertiary centres scattered across the globe. These findings should serve as a baseline for future studies evaluating the epidemiological landscape of these tumours.

Impact of tumor site on the prognosis of salivary gland neoplasms: A systematic review and meta-analysis.

In numerous types of cancer, the primary tumor site can show a correlation with disease behavior and survival outcomes. In salivary gland tumors (SGTs) this association remains controversial. This study assessed the association between primary sites of SGTs and prognosis. Studies from five databases were assessed and a meta-analysis was performed using studies that presented 95 % confidence interval (95 % CI), hazard ratio (HR) and survival analysis. Gathered information from 46,361 patients showed that site had a prognostic impact on SGTs. Tumors involving minor salivary glands showed worse overall survival (HR = 1.60; 95 % CI = 1.17-2.19; p = 0.003), disease-specific survival (HR=1.63; 95 % CI = 1.12-2.37; p = 0.01), and cause-specific survival (HR=2.10; 95 % CI = 1.72-2.55; p = 0.00001). Tumors from major salivary glands showed better recurrence-free survival (HR=2.31; 95 % CI = 1.77-3.02; p = 0.00001), and locoregional control of disease (HR=2.66; 95 % CI = 1.20-5.91; p = 0.02). Our results showed that the primary site of SGTs has an impact on patient prognosis.

Assessment of fluoride concentrations in commercially available mouthrinses in central Saudi Arabia.

OBJECTIVES: To assess the fluoride concentration of different commercially available mouthrinses in central Saudi Arabia, and compare the obtained measurements with label values. METHODS: This cross-sectional study identified 25 brands of mouthrinses in the markets of Riyadh city  between August and September 2013. Nineteen brands of mouthrinses whose labels indicate the percentage of sodium fluoride (NaF) and 6 brands not indicating the fluoride percentage were included in the study. Three bottles of 2 manufacturing batches of each brand were acquired, coded, and analyzed after dilution using specific electrodes for fluoride and an ion analyzer at the College of Science, King Saud University, Riyadh, Saudi Arabia.   RESULTS: The average fluoride concentrations in the tested mouthrinses ranged from 8.4 ppm (Voza) to 448.7 ppm (Sensodyne `Pronamel`). Analysis of variance showed a statistically significant difference (p<0.05) in the fluoride concentration between the studied 25 brands. Almost 60% of the brands' fluoride concentrations were significantly different (mainly lower) from the label value. However, only 5 brands contain fluoride at a concentration not significantly different from the recommended fluoride concentration in daily mouthrinses 0.05% (225 ppm). CONCLUSION: Most of the studied commercially available mouthrinses contain topical fluoride at concentrations below the manufacturers' label value, but above the recommended 0.05%.