Processing and Analysis of Tissue Samples from Esophageal Cancer Patients in an African Setting.

Although infectious diseases continue to present a major health care problem in Africa, the incidence of cancer is increasing rapidly on the African continent and this merits an increased investment in cancer research in low to medium resource settings. Esophageal squamous cell carcinoma (ESCC) has a high incidence in Eastern and Southern Africa, with late clinical presentation and a very poor prognosis. There is limited research on the molecular pathology of this cancer in Africa, partly as a result of a lack of infrastructure for biobanking and sample processing in many African countries. The aim of this study was to establish a practical and robust workflow to collect, store, and process esophageal cancer samples such that both the tissue architecture and quality of the samples would be preserved and suitable for future genomic research. We developed a workflow that allows storage of fresh biopsy tissue in sterile Eppendorf tubes containing RNAlater, an efficient RNAse inhibitor. We collected 142 ESCC biopsy samples and showed that storage in RNAlater for up to 18 months did not alter tissue morphology, thus allowing histologic assessment by experienced pathologists and determination of tumor content in each biopsied sample. DNA and RNA extracted from tissue samples was assessed for purity, molecular size, and yield. The quantity and quality of nucleic acids obtained were suitable for genomic applications, and whole-exome sequencing of DNA from tumor tissues produced sequence data with a high proportion of both usable reads and correct base calling. We conclude that this workflow may be applicable to a wide range of malignancies for future genomic research in low-resource settings.

Custom Focal Trough in Cone-Beam Computed Tomography Reformatted Panoramic Versus Digital Panoramic for Mental Foramen Position to Aid Implant Planning.

OBJECTIVES: To compare the linear measurements from digital panoramic (DP) radiographs and cone-beam computed tomography (CBCT) volumes for the localization of the mental foramen (MF). MATERIAL AND METHODS: Thirty-one patients with panoramic and CBCT radiographs depicted on the same machine were analyzed. The vertical and horizontal positions of the MF were compared by the differences in distances measured from reference points to the boundaries (tangents) of the MF in digital panoramic (DP) and CBCT reformatted panoramic (CRP) views. The vertical position of MF was also analyzed on CBCT oblique coronal views (CORO) and compared with its corresponding distances on DP and CRP views. RESULTS: Statistically significant differences (P < 0.05) were found in all compared measurements between CRP and DP views. In addition, the vertical distance (Y1) compared between DP, CRP, and CORO views also showed a statistically significant measurement discrepancy in the mean distance (P < 0.000) with the highest mean difference of 1.59 mm (P < 0.05) was attained from Y1 (DP-CORO). Inter- and intra-examiner analysis indicated a high level of agreement for all measurements. CONCLUSION: The mean values of discrepancies in measurements between DP and CRP views for horizontal and vertical linear measurements were clinically tolerable. Nevertheless, significant differences in the vertical MF position were detected between the panoramic views (DP, CRP) and the coronal views (CORO). This implies that the use of coronal view measurements during implant planning might reduce the risk of neurovascular injuries.

Molecular landscape of esophageal cancer: implications for early detection and personalized therapy.

Esophageal cancer (EC) is one of the most lethal cancers and a public health concern worldwide, owing to late diagnosis and lack of efficient treatment. Esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) are main histopathological subtypes of EC that show striking differences in geographical distribution, possibly due to differences in exposure to risk factors and lifestyles. ESCC and EAC are distinct diseases in terms of cell of origin, epidemiology, and molecular architecture of tumor cells. Past efforts aimed at translating potential molecular candidates into clinical practice proved to be challenging, underscoring the need for identifying novel candidates for early diagnosis and therapy of EC. Several major international efforts have brought about important advances in identifying molecular landscapes of ESCC and EAC toward understanding molecular mechanisms and critical molecular events driving the progression and pathological features of the disease. In our review, we summarize recent advances in the areas of genomics and epigenomics of ESCC and EAC, their mutational signatures and immunotherapy. We also discuss implications of recent advances in characterizing the genome and epigenome of EC for the discovery of diagnostic/prognostic biomarkers and development of new targets for personalized treatment and prevention.

Nevoid basal cell carcinoma syndrome: a 40-year study in the South African population.

BACKGROUND: Nevoid basal cell carcinoma syndrome (NBCCS) is a hereditary autosomal dominant syndrome presenting with a number of signs and symptoms in different population groups. METHODS: The investigators implemented a 40-year retrospective analysis of the clinical and radiological features of South Africans affected by NBCCS presenting at the Departments of Oral Surgery, Pathology and Radiology of two major referral hospitals. Details of age, gender, ethnic origin, clinical, and radiological findings were recorded and compared to previous reports. A list of diagnostic criteria for diagnosis of NBCCS in this population was complied. Descriptive statistics were computed, and the P value was set at 0.05 or less. RESULTS: The sample was composed of 15 patients. The mean age at the time of diagnosis was 22.7years (SD 20.9) with eight (53.3%) patients diagnosed before 20years of age (P=0.0001). The male: female ratio was 2:1. The most frequent major criteria were keratocystic odontogenic tumors (KCOTs) (100%), calcification of falx cerebri (40%), palmo-plantar pits (26.7%), and basal cell carcinomas (BCCs) (20%). The most frequent minor criteria were bifid ribs (20%), skull anomalies (20%), and hypertelorism (20%). CONCLUSIONS: The results of this study indicate that there was a low frequency of falx cerebri calcifications, BCCs, skull, and rib anomalies in this sample compared to other population groups. These differences could be attributed to genetic, racial, and environmental factors. Future studies are needed to compile diagnostic criteria specific to different population groups.