Background Cancer is emerging as a major global health-care system challenge with a growing burden worldwide. Due to the inconsistent cancer registry system in Saudi Arabia, the epidemiology of cancer is still dispersed in the country. Consequently, this review aimed to assemble the epidemiological metrics of cancer in Saudi Arabia in light of the available published data during the period from (2010–2019). Methods Published literature from Saudi Arabia relating to cancer incidence, prevalence, risk factors, and other epidemiological metrics were accessed through electronic search in Medline/PubMed, Cochrane, Scopus, Web of Knowledge, Google Scholar, and public database that meet the inclusion criteria. Relevant keywords were used during the electronic search about different types of cancers in Saudi Arabia. No filters were used during the electronic searches. Data were pooled and odds ratios (ORs) and 95% confidence interval (95%CI) were calculated. A random-effects meta-analysis was performed to assess the well-determined risk factors associated with different types of cancers. Results The most common cancers in Saudi Arabia are breast, colorectal, prostate, brain, lymphoma, kidney and thyroid outnumbering respectively. Their prevalence rates and OR (95%CI) as follow: breast cancer 53% and 0.93 (0.84–1.00); colon-rectal cancer (CRC) 50.9% and 1.2 (0.81–1.77); prostate cancer 42.6% and 3.2 (0.88–31.11); brain/Central Nervous System cancer 9.6% and 2.3 (0.01–4.2); Hodgkin and non-Hodgkin's lymphoma 9.2% and 3.02 (1.48–6.17); kidney cancer 4.6% and 2.05 (1.61–2.61), and thyroid cancer 12.9% and 6.77 (2.34–19.53). Conclusion Within the diverse cancers reported from Saudi Arabia, the epidemiology of some cancers magnitude 3-fold in the latest years. This increase might be attributed to the changing in the Saudi population lifestyle (adopting western model), lack of cancer awareness, lack of screening & early detection programs, social barriers toward cancer investigations. Obesity, genetics, sedentary lifestyle, tobacco use, viral infection, and iodine & Vit-D deficiency represent the apparent cancer risk factors in Saudi Arabia.

Background In recent years, there is an emerging increase in the prevalence of oral and oropharyngeal cancers (O-OPCs) across the Arabian Gulf Cooperation Council (GCC) countries. Consequently, this review aimed to explore the epidemiology and possible risk factors of O-OPCs in GCC countries. Methods Data published after 2008 related to O-OPCs in GCC countries were obtained through electronic searches in Medline/PubMed, Scopus, Web of Science, EMBASE and Google Scholar. Keywords related to the association between O-OPCs metrics (epidemiology and risk factors) and GCC countries were used for electronic searches. Results The overall prevalence of OPCs increased significantly over time (40-51%) in some countries (Saudi Arabia and Arab Emigrated) of the Gulf regions. The pooled risk factor was 3.4 (2.5 - 4.7). Among the risk factors, human papillomavirus and the use of smoke and smokeless tobacco revealed odds ratio (OR) 3.31 (3.13 - 4.5) and 0.60 (0.45 - 0.80) at 95% confidence interval (CI). Conclusion A positive correlation between factors like age, diet, hygiene, genetics, viral and bacterial infection, consumption of alcohol and tobacco products with OPC-MFC is suggested.

Background Khat leaves contain the alkaloid cathinone. Research shows that khat might provoke toxicity, mutagenicity, as well as carcinogenicity. Methods Two groups were identified as khat abusers and were categorized by abuse time and diagnosis of oral squamous cell carcinoma (OSCC). Here, 41 participants from Group 2 were short-term khat users, and 42 participants were long-term khat users. The control group included 30 healthy individuals. The coding exons included nine cancer-related genes and were analysed. The histopathological research was conducted with H&E staining along with the TP53 protein expression by implementing immunohistochemical analyses. Results Here, 41 short-term khat users carried seven somatic mutations in four out of nine cancer-related genes: 29/41(70.73%) ARID1A, 24/41(58.53%) MLH1, 34/41(82.92%) PIK3CA and 36/41(87.80%) TP53. The 42 long-term khat users incorporated nine somatic mutations in five out of nin ecancer-related genes: 40/42(95.23%) ARID1A, 36/42(85.71%) ARID2, 29/42(69.04%) PIK3CA, 27/42(64.28%) MLH1, and 35/42(83.33%) TP53. Every khat user had somatic mutations related to OSCC affecting the gingiva and the lower lip. TP53 protein expression was confirmed in all immunohistochemical oral tests. Carcinoma was also positive in the histopathological analysis. Conclusions Khat is a mutagenic and carcinogenic plant that provoked OSCC among short-term khat users (<15 years of use) and long-term users (>15 years of use).

Background: The current study has been conducted to estimate the impact of Catha Edulis Forsk (simply known as khat) on pH and saliva flow rate in teeth unaffected by caries among patients from Arab, Yemen, consuming the plant. The goal was to evaluate the relation of these indicators with gene manifestation of CHRM1 and CHRM3, which contributes to the regulation of saliva secretions. Methods: Overall, 60 respondents aged between 27 and 54 years were selected for the research. They were distributed among two groups, group I and group II, including 30 respondents equally. Group I incorporated respondents consuming no khat, having teeth caries, adequate saliva flow, and generally, healthy oral cavity. In turn, group II incorporated respondents consuming khat having caries-free teeth, inadequate saliva flow and relatively unhealthy oral cavity. Saliva samples were taken from all respondents. They were analyzed for indicators of flow rate as well as pH of saliva. Salivary gland biopsy specimens have also been taken. The whole RNA was allocated, cDNA synthesized and reinforced to estimate the gene manifestation of CHRM1 and CHRM3. Results: A considerable rise in the mean salivary flow rate along with a drastic decline in the mean salivary pH within caries-free teeth among the respondents consuming khat was observed during the study. The mRNA expressions CHRM1 and CHRM3 were significantly increased among participants consuming khat. Results were contrasted to the control group of patients not consuming khat. Conclusion: The characteristics of salivary flow rate, pH, and caries-free teeth have been related to the gene manifestations of CHRM1 and CHRM3 in respondents consuming khat.

Background: Prognosis of nonsurgical endodontic treatment has been extensively studied over the last decades; however, the data obtained is insuffi cient. The purpose of this study was to retrospectively analyze the outcomes of initial endodontic treatment, and tooth retention over 5 years. Materials and Methods: In this study, the treatment database of the King Khalid University Dental Clinics (KKUCD) is used to identify patient's undergone nonsurgical endodontic treatment in the year 2009. 779 patients were treated by students, interns, and specialists in KKUCD. 205 patients (217 teeth) were recalled and examined their teeth presence (retention), endodontic lesion healing status, and medical history status. Results: Among the 217 teeth, 208 were retained and 9 were extracted in 5 years. The 217 teeth, 34 treated by specialists, 90 by interns, and 93 by students. The 9 extracted teeth were 3 treated by specialists, 1 by interns, and 5 by students. The 9 extracted teeth were 4 maxillary premolars, 2 maxillary molars, 2 mandibular premolars, and 1 mandibular anterior. Using Chi-square tests, survival endodontic cases which had uncertain to successful endodontic healing are 27 treated by specialists, 86 by interns, and 75 by students. There was a signifi cant diff erence (P = 0.000) in endodontic success and survivability between the normal medical status and insulin-dependent diabetes patients. Conclusions: Within the limitations of this study, the survivability of nonsurgical endodontic treatment is very highly predictable 90%. Prosthodontics consideration is highly important since all extracted teeth in the study were not crowned. Nonsurgical endodontic treatment within insulin-dependent diabetes patients has fair to poor prognosis, which shows a less rate of success in comparison to other compromised patients.