Epithelial PD-L1 expression at tumor front predicts overall survival in a cohort of oral squamous cell carcinomas from Sudan.

BACKGROUND: We recently described the tumor immune microenvironment (TIME) in oral squamous cell carcinomas (OSCC) from Sudan by assessing the core of the lesions. However, the invasive tumor front (ITF) is the most active part of OSCC lesions; thus, TIME should also be characterized at the ITF in this patient cohort. OBJECTIVES: We aimed to evaluate patterns of immune cell infiltration at the ITF in a cohort of OSCC patients from Sudan previously investigated at the tumor center and their association with clinicopathological parameters. METHODS: This study was performed on a prospective cohort of 22 OSCC patients attending Khartoum Dental Teaching Hospital with a median follow-up of 48 months. Inflammatory infiltrate densities of CD4-, CD8-, FoxP3-, CD20-, CD66b-, M1 (CD80/CD68)-, M2 (CD163/CD68)-, and PD-L1-positive cells were assessed at the ITF by immunohistochemistry, followed by digital quantitative analysis at the stromal and epithelial compartments separately. Histopathological parameters such as the worst pattern of invasion, differentiation, and tumor budding (TB) were also assessed. Correlations between clinicopathological parameters and survival analysis were investigated using SPSS. RESULTS: All inflammatory cell subsets investigated were found to be higher in the stromal compartment as compared to the epithelial one, except for the PD-L1+ subset. Stromal infiltration with the CD8+ cell subset was associated with low TB. Kaplan-Meier analyses identified higher epithelial and stromal CD4+ cell subsets. The presence of PD-L1 was found to be associated with unfavorable overall survival. Further, Cox's regression analysis using an age- and tumor-stage-adjusted model identified epithelial PD-L1 expression at the ITF as the only independent prognosticator. CONCLUSIONS: Epithelial PD-L1 expression at the ITF was found to be an independent prognostic biomarker for OSCC in a cohort of Sudanese patients.

The epidemiology of autoimmune bullous diseases in Sudan between 2000 and 2016.

OBJECTIVES: Autoimmune bullous diseases vary in their clinico-epidemiological features and burden across populations. Data about these diseases was lacking in Sudan. We aimed to describe the epidemiological profile and to estimate the burden of autoimmune bullous diseases in Sudan. METHODS: This was a retrospective cross-sectional study conducted at Khartoum Dermatological and Venereal Diseases Teaching Hospital. We used routinely collected health care data, and included all patients with an autoimmune bullous disease who presented to the hospital between 2001 and 2016. RESULTS: Out of the 4736 patients who were admitted to the hospital during the study period, 923 (19.5%) had an autoimmune bullous disease. The average rate of patients at the hospital was 57.7 per year representing 1.3 per 100,000 population per year. After exclusion of patients where the final diagnosis was missing, 585 were included in the further analysis. Pemphigus vulgaris was the most common disease (50.9%), followed by bullous pemphigoid (28.2%), linear IgA disease/chronic bullous disease of childhood (8.4%), and pemphigus foliaceous (8.2%). Pemphigoid gestationis and IgA pemphigus constituted 1.4% and 1.2% of the cohort, respectively. Paraneoplastic pemphigus, mucous membrane pemphigoid, lichen planus pemphigoidis, bullous systemic lupus erythematosus, and dermatitis herpetiformis were rare. None of the patients had epidermolysis bullosa acquisita. CONCLUSIONS: The clinico-epidemiological characteristics vary among the types of autoimmune bullous diseases. Females were more predominant in most of them. Sudanese patients tended in general to present at a younger age than other populations. The pool of Sudanese patients with autoimmune bullous diseases is large which requires investigation for the local risk factors and presents a field for future trials.

Oral leukoplakia in the Sudan: clinicopathological features and risk factors.

OBJECTIVES: To analyse the clinical and histopathological features of oral leukoplakia (OL) in the Sudan, and to identify the risk factors associated with dysplastic and malignant changes. METHODS: Records of 117 cases with the diagnosis of OL at the Department of Oral Pathology in the period from 2010 to 2017 were reviewed. RESULTS: Of the 117 cases included in this study, 30 cases (25.6%) showed carcinoma in the initial diagnostic biopsy. The mean age at diagnosis was 59.8 years with a male/female ratio of 3.3:1. The lip (48.7%) and the gingiva (31.6%) were the predominantly affected sites. Multivariate regression analysis revealed that females were associated with 3.36-fold [95% confidence interval (CI), 1.36-10.76; P = 0.012] higher risk of malignant transformation compared with males. Verrucous leukoplakia was associated with 3.38-fold (95% CI,  1.12-10.19; P =  0.031) higher risk of malignant transformation compared with homogeneous leukoplakia. Exclusive Toombak dipping was the significant risk factor for the presence of dysplasia in OL (odds ratio, 9.35; 95% CI, 1.28-67.99; P = 0.027). CONCLUSIONS: Clinical and histopathological features of OL were analysed and correlated. Toombak dipping was the significant risk factor for dysplastic changes, while female gender and verrucous leukoplakia were the factors associated with malignant transformation.

Viral infection and oral habits as risk factors for oral squamous cell carcinoma in Yemen: a case-control study.

OBJECTIVE: The role of qat chewing, tobacco (shammah) dipping, smoking, alcohol drinking, and oral viral infection as risk factors for oral squamous cell carcinoma (OSCC) in Yemen was assessed. STUDY DESIGN: A total of 60 cases of OSCC and 120 age- and gender-matched controls were analyzed with respect to demographic data, history of oral habits, and the presence of human papillomavirus (HPV)-16, HPV-18, or Epstein-Barr virus (EBV) as determined by Taqman quantitative polymerase chain reaction. Logistic regression analysis was used to identify independent predictors of the disease. RESULTS: Shammah use was the only risk factor for OSCC, with an odds ratio of 12.6 (CI, 3.3-48.2) and 39 (CI, 14-105) for the ex-users and current users, respectively. The association of shammah use alone with OSCC exceeded that of shammah use in combination with qat chewing, smoking, or both. EBV infection, smoking, and qat chewing showed no association with OSCC, while neither HPV-16 nor HPV-18 were detected in any sample. CONCLUSIONS: Shammah use is a major risk factor for oral cancer in Yemen.

Pattern of malignant tumors registered at a referral oral and maxillofacial hospital in Sudan during 2006 and 2007.

BACKGROUND: A progressive increase in the incidence and mortality of oral cancer is expected in Sudan. However, updated information on the epidemiology and pattern of the disease in the country is needed to draw the attention of the local authorities. AIM: The aim of this study has been to describe the pattern of cancer cases attending a referral oral and maxillofacial hospital in Sudan during the period 2006-2007. SETTINGS AND DESIGN: The investigation was conducted as a cross-sectional study using the hospital records. MATERIALS AND METHODS: From the hospital database, all cancer cases registered during the study period have been reported and their demographic characteristics, clinical information and history of oral habits were included. STATISTICS: Statistical Package for Social Sciences (version 12) was used for data analysis. Frequency distributions of the study variables were made and the association between pairs of variables was examined using the Chi-square test with a level of significance of 0.01. RESULTS AND CONCLUSION: Of the 261 cases included in this study, the most common pattern was found to be an intraoral squamous cell carcinoma (73.6%). The male to female ratio was approximately 3:2. Dropout rates were alarmingly high regardless of the patient's state of residence. The observation of this study indicated that most of the patients seek treatment when the tumor reaches late stage. More public health efforts are therefore needed to investigate the current impact of the problem as well as for prevention and early detection of the cases.