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

Nasher, Akram Thabet; Al-Hebshi, Nezar N.; Al-Moayad, Ebtisam E.; Suleiman, Ahmed Mohamed

doi:10.1016/j.oooo.2014.08.005

Cited by 51 publications

(67 citation statements)

References 33 publications

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“…Though cigarette smoking (number of cigarettes per day) is observed to have an effect on the occurrence of the disease, shamma (smokeless tobacco) was seen to be majorly associated with oral cancer among the study sample. Similar type of impact of shamma has also been demonstrated by Nasher (2014) and his colleagues when they performed their study in a different study setting (Nasher et al, 2014).…”

Section: Discussionsupporting

confidence: 76%

“…But in other parts of the world such as in the African country of Sudan, it is seen that Toombak and Safa (smokeless tobacco) showed a strong association with oral cancer (Elbeshir et al, 1989;Idris et al, 1995a;1995b). The odds ratio obtained in this study and the one that was done in Yemen (Nasher et al, 2014) is significantly higher indicating its strong carcinogenic effect. The presence of tobacco-specific nitrosamines (TSNAs) and polycyclic aromatic hydrocarbons is the key in identifying the differences in carcinogenicity of shamma, toombak, snus and various other available substances (IARC, 2012).…”

Section: Discussionmentioning

confidence: 47%

“…Noticing the spread of this deadly disease in the region, it was necessary to initiate a study in order to gather the evidence of various potential risk factors involved within the local population. The authors report that this study is the first of its kind to assess the association of various locally used risk factors to oral cancer in the Jazan region and it is the second such study to be conducted in the Southern Arabian Peninsula (Nasher et al, 2014).…”

Section: Discussionmentioning

confidence: 99%

“…For sampling, one previous study was scrutinized involving the use of similar risk factor among the people living in Yemen, which obtained an odds ratio of 12.6 (95%CI, 3.3-48.2) (Nasher et al, 2014). Considering this to be a minimum odds ratio that the current study should obtain to confirm the association of the use of shamma with oral cancer, a minimum sample size was calculated.…”

Section: Study Setting and Samplementioning

confidence: 99%

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Oral Squamous Cell Carcinoma and Associated Risk Factors in Jazan, Saudi Arabia: A Hospital Based Case Control Study

Quadri

Alharbi²,

Bajonaid³

et al. 2015

Asian Pacific Journal of Cancer Prevention

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Background: Oral cancer is the third most common malignancy in Saudi Arabia, the highest incidence of which is reported from Jazan province. The objective of this study was to evaluate the association of various locally used substances, especially shamma, with oral cancer in the Jazan region of Saudi Arabia. Materials and Methods: A hospital-based case-control study was designed and patient records were scanned for histologically confirmed oral cancer cases. Forty eight patients who were recently diagnosed with oral cancer were selected as cases. Two healthy controls were selected for each observed case and they were matched with age (+/-5 years) gender and location. Use of different forms of tobacco such as cigarettes, pipe-smoking and shamma (smokelesstobacco) was assessed. Khat, a commonly used chewing substance in the community was also included. Descriptive analysis was first performed followed by multiple logistic regression (with and without interaction) to derive odds ratios (ORs) and 95% confidence interval (CIs). Results: Mean age of the study sample (56% males and 44% females) was 65.3 years. Multinomial regression analysis revealed that shamma use increased the odds of developing oral cancer by 29 times (OR=29.3; 10.3-83.1). Cigarette (OR=6.74; 2.18-20.8) was also seen to have an effect. With the interaction model the odds ratio increased significantly for shamma users (OR=37.2; 12.3-113.2) and cigarette smokers (OR=10.5; 2.88-3.11). Khat was observed to have negative effect on the disease occurrence when used along with shamma (OR=0.01; 0.00 -0.65). Conclusions: We conclude that shamma, a moist form of smokeless tobacco is a major threat for oral cancer occurrence in the Jazan region of Saudi Arabia. This study gives a direction to conduct further longitudinal studies in the region with increased sample size representing the population in order to provide more substantial evidence.

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Section: Discussionsupporting

confidence: 76%

Section: Discussionmentioning

confidence: 47%

Section: Discussionmentioning

confidence: 99%

Section: Study Setting and Samplementioning

confidence: 99%

See 2 more Smart Citations

Oral Squamous Cell Carcinoma and Associated Risk Factors in Jazan, Saudi Arabia: A Hospital Based Case Control Study

Quadri

Alharbi²,

Bajonaid³

et al. 2015

Asian Pacific Journal of Cancer Prevention

View full text Add to dashboard Cite

show abstract

“…For example, overall evidence strongly indicates that use of Swedish snus poses a very small risk of oral cancer development and that use of American chewing tobacco and moist snuff are associated with a very low risk [2][3][4]. On the contrary, strong association has been reported from other parts of the world between oral cancers and use of certain types of ST, including toombak and saffa in Sudan [5][6][7], shammah in Yemen and the South of Saudi Arabia [8][9][10], and almost all forms of chewing tobacco in India [11,12]. This variation in carcinogenicity of ST products has been mainly attributed to differences in the concentrations of carcinogenic chemicals primarily tobacco-specific N-nitrosamines (TSNAs).…”

Section: Introductionmentioning

confidence: 99%

Differences in the Bacteriome of Smokeless Tobacco Products with Different Oral Carcinogenicity: Compositional and Predicted Functional Analysis

Al-Hebshi

Alharbi

Mahri

et al. 2017

Preprint

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Smokeless tobacco (ST) products vary significantly in their oral carcinogenicity. Much is known about the differences in chemical, but not bacterial, constituents of these products. In this study, we explore the composition and function of the bacteriome in ST products from 4 countries using q-PCR and 16S rRNA-based next generation sequencing. The bacterial load (16S rRNA copies/gram) was lowest in Swedish snus (3.4E+6) and highest in Yemeni shammah (6.6E+11). A total of 491 species-level taxa, many of which are potentially novel, belonging to 178 genera and 11 phyla were identified. Species richness and diversity were highest for Swedish snus and lowest for Yemeni and nickel transport systems were enriched in the presumptively "high carcinogenicity" products.The bacteriome of ST products thus differed qualitatively, quantitatively and functionally. The relevance of these differences, particularly with respect to nickel and cadmium, to oral carcinogenesis warrants further investigation.

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Exome sequencing of oral squamous cell carcinoma in users of Arabian snuff reveals novel candidates for driver genes

Al-Hebshi

Nasher

et al. 2016

Intl Journal of Cancer

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The study sought to identify genetic aberrations driving oral squamous cell carcinoma (OSCC) development among users of shammah, an Arabian preparation of smokeless tobacco. Twenty archival OSCC samples, 15 of which with a history of shammah exposure, were whole-exome sequenced at an average depth of 127×. Somatic mutations were identified using a novel, matched controls-independent filtration algorithm. CODEX and Exomedepth coupled with a novel, Database of Genomic Variant-based filter were employed to call somatic gene-copy number variations. Significantly mutated genes were identified with Oncodrive FM and the Youn and Simon’s method. Candidate driver genes were nominated based on Gene Set Enrichment Analysis. The observed mutational spectrum was similar to that reported by the TCGA project. In addition to confirming known genes of OSCC (TP53, CDKNA2, CASP8, PIK3CA, HRAS, FAT1, TP63, CCND1 and FADD) the analysis identified several candidate novel driver events including mutations of NOTCH3, CSMD3, CRB1, CLTCL1, OSMR and TRPM2, amplification of the proto-oncogenes FOSL1, RELA, TRAF6, MDM2, FRS2 and BAG1, and deletion of the recently described tumor suppressor SMARCC1. Analysis also revealed significantly altered pathways not previously implicated in OSCC including Oncostatin-M signalling pathway, AP-1 and C-MYB transcription networks and endocytosis. There was a trend for higher number of mutations, amplifications and driver events in samples with history of shammah exposure particularly those that tested EBV positive, suggesting an interaction between tobacco exposure and EBV. The work provides further evidence for the genetic heterogeneity of oral cancer and suggests shammah-associated OSCC is characterized by extensive amplification of oncogenes.

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

Cited by 51 publications

References 33 publications

Oral Squamous Cell Carcinoma and Associated Risk Factors in Jazan, Saudi Arabia: A Hospital Based Case Control Study

Oral Squamous Cell Carcinoma and Associated Risk Factors in Jazan, Saudi Arabia: A Hospital Based Case Control Study

Differences in the Bacteriome of Smokeless Tobacco Products with Different Oral Carcinogenicity: Compositional and Predicted Functional Analysis

Exome sequencing of oral squamous cell carcinoma in users of Arabian snuff reveals novel candidates for driver genes

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