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date, most of the epidemiological studies on salivary gland tumours are limited for a variety of reason including being out of date, extrapolated from either a single centre or country studies, or investigating either major or minor glands only.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.

Improving the management of early colorectal cancers (eCRC) by using quantitative markers to predict lymph node involvement and thus the need for major resection of pT1 cancers.

BACKGROUND: Since implementing the NHS bowel cancer screening programme, the rate of early colorectal cancer (eCRC; pT1) has increased threefold to 17%, but how these lesions should be managed is currently unclear. AIM: To improve risk stratification of eCRC by developing reproducible quantitative markers to build a multivariate model to predict lymph node metastasis (LNM). METHODS: Our retrospective cohort of 207 symptomatic pT1 eCRC was assessed for quantitative markers. Associations between categorical data and LNM were performed using χ2 test and Fisher's exact test. Multivariable modelling was performed using logistic regression. Youden's rule gave the cut-point for LNM. RESULTS: All significant parameters in the univariate analysis were included in a multivariate model; tumour stroma (95% CI 2.3 to 41.0; p=0.002), area of submucosal invasion (95% CI 2.1 to 284.6; p=0.011), poor tumour differentiation (95% CI 2.0 to 358.3; p=0.003) and lymphatic invasion (95% CI 1.3 to 192.6; p=0.028) were predictive of LNM. Youden's rule gave a cut-off of p>5%, capturing 18/19 LNM (94.7%) cases and leading to a resection recommendation for 34% of cases. The model that only included quantitative factors were also significant, capturing 17/19 LNM cases (90%) and leading to resection rate of 35% of cases (72/206). CONCLUSIONS: In this study, we were able to reduce the potential resection rate of pT1 with the multivariate qualitative and/or quantitative model to 34% or 35% while detecting 95% or 90% of all LNM cases, respectively. While these findings need to be validated, this model could lead to a reduction of the major resection rate in eCRC.

Area of submucosal invasion and width of invasion predicts lymph node metastasis in pT1 colorectal cancers.

BACKGROUND: The prediction of lymph node metastasis by current histopathological methods is imprecise. OBJECTIVE: The aim of this study was to evaluate currently used and possible new high-risk features associated with lymph node metastasis to identify the markers of lymph node metastasis. DESIGN/PATIENT/SETTING: Two hundred seven pT1 cancers were identified through the Northern and Yorkshire Cancer Registry and Information Services database and digitally scanned. Phenotypic and quantitative features of the pT1 cancers were evaluated. Lymph node metastasis and high-risk feature status were obtained through pathology reports of resections, and high-risk phenotypic features were identified. RESULTS: Lymph node metastasis was noted in 19 patients (9.2%). pT1 cancers with lymph node metastasis had a significantly wider area of invasion (p = 0.001) and greater area of submucosal invasion (p < 0.001) compared with pT1 cancers without lymph node metastasis. Qualitative features such as grade of differentiation and vascular and lymphatic invasion were significant predictors of lymph node metastasis (p < 0.0001, p = 0.039, and p = 0.018). Modified receiver-operating characteristics curves generated cutoff values of 11.5 mm for the width of invasion and 35 mm(2) for the area of submucosal invasion. When tested separately with other qualitative factors on multivariate analysis, both width greater than 11.5 mm (OR, 12.12; 95% CI, 2.19-67.23; p = 0.004) and area of submucosal invasion greater than 35 mm(2) (OR, 22.44; 95% CI, 2.7-186.63; p = 0.004) was predictive of lymph node metastasis. LIMITATIONS: This is a retrospective study and is limited by its small sample size. CONCLUSION: This study has shown that the width and area of submucosal invasion are potential predictors of lymph node metastasis and superior to the depth of invasion. Together with the other qualitative phenotypic features, these quantitative factors could be used to decide the most appropriate treatment for pT1 cancers.

New insights into the lymphovascular microanatomy of the colon and the risk of metastases in pT1 colorectal cancer obtained with quantitative methods and three-dimensional digital reconstruction.

AIMS: UK faecal occult blood test screening has tripled the proportion of pT1 colorectal cancers. The risk of metastasis is predicted by depth of invasion, suggesting that access to deep lymphovascular vessels is important. The aim of this study was to quantify the distribution and size of the submucosal vasculature, and generate a novel three-dimensional (3D) model to validate the findings. METHODS AND RESULTS: Thirty samples of normal large bowel wall were immunostained with CD31, a vascular endothelium marker, to identify blood vessels, which were quantified and digitally analysed for their number, circumference, area and diameter in the deep mucosa and submucosa (Sm1, Sm2, and Sm3). The model required serial sections, a double immunostain (using CD31 and D2-40), and 3D reconstruction. Significant differences were shown between submucosal layers in the number, circumference and area of vessels (P < 0.001). Blood vessels were most numerous in the mucosa (11.79 vessels/0.2 mm(2)) but smaller [median area of 247 µm(2) , interquartile range (IQR) 162-373 µm(2)] than in Sm2, where they were fewer in number (6.92 vessels/0.2 mm(2)) but considerably larger (2086 µm(2), IQR 1007-4784 µm(2)). The 3D model generated novel observations on lymphovascular structures. CONCLUSIONS: The number and size of blood vessels do not increase with depth of submucosa, as hypothesized. The distribution of vessels suggests that we should investigate the area or volume of submucosal invasion rather than the depth.

An atypical presentation of colorectal cancer.

Colorectal cancer is a common type of cancer in developed countries and is an important public health problem. Patients with colorectal cancer presents in a variety of ways in different settings. Most commonly, they present in the outpatient settings with changes in bowel habits, rectal bleeding and iron deficiency anaemia. This case reports an atypical presentation of colorectal cancer and how the cancer was diagnosed and treated.