Table 1. Incidence, Prevalence and Possible Risk Factors of O-OPCs in GCC Countries.
| Study parameters | Country | Source of data | Period | No. of cases/biopsies) under study (n) | Age group | Common malignant lesions type | The highest site of lesion | Risk factor distribution among patients | Reference |
|---|---|---|---|---|---|---|---|---|---|
| Retrospective study | Saudi Arabia | Cancer registry | 1994 - 2007 | 5,862 | 29 - 71 | OC, PC = 245 (4.2%) | Tongue (> 42%) | NS | [16] |
| A multicenter, retrospective study of oral biopsies | UAE | Hospital records | 2008 - 2010 | 992 | 28 - 89 | OSCC | Tongue (51.9%) | NS | [13] |
| Cross-sectional | Extended the Middle East* and North Africa | Cancer registry | 2008 | 252 | NS | OC, pharynx | OC | HPV | [18] |
| Case-control | Saudi Arabia | Hospital-based | 2011 - 2013 | 599 | ≥ 18 | NS | Smokeless keratosis (6.3%) | Tobacco chewers | [19] |
| Case-control | Saudi Arabia | Hospital-based | 2014 | 48 | About 65.3 | OC | NS | Khat 2 (1/28%) Shannah 39 (27.08%) Cigarette 10 (6.94%) Pipe 9 (6.24%) |
[20] |
| Prospective study | Saudi Arabia | Hospital records | 2002 - 2009 | 2,232 | 36 - 54 | Head and neck/ORN | Nasopharyngeal 35 (39.2%) Mandible 27 (30.4%) |
Smoking 42 (47.3%) Smokeless 6 (6.7%) |
[21] |
| Cross-sectional | Middle East# and North Africa | Public database | 2012 | 8,928 | NS | OCC-OPC, NS | NS | NS | [10] |
| Retrospective study | Saudi Arabia | Hospital records | NS | 2,850 | ≤ 10 - 70 | SCC, VC, S | Tongue (47%) | NS | [22] |
| Retrospective study | Saudi Arabia | Hospital records | 2009 - 2014 | 714 | < 1 - 100 | OML-OSCC | Tongue | Shammah user OSCC 45.5% Male: 87 (31.6%) Female: 40 (68.4%) |
[17] |
| Retrospective study | UAE | Hospital records/cancer registry | 1998 - 2014 | 314 | NS | ADC, SCC, MEC, ACC | Salivary gland tumor (74%) | NS | [23] |
*Included in this study: Bahrain, Kuwait Oman; #Included in this study: Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and UAE. NS: not specified; OSCC: oral squamous cell carcinoma; SCC: squamous cell carcinoma; OML: oral and maxillofacial; VC: verrucous sarcoma; S: sarcoma; ADC: adenocarcinoma; MEC: mucoepidermoid carcinoma; ACC: acinar cell carcinoma; O-OPCs: oral and oropharyngeal cancers; GCC: Arabian Gulf Cooperation Council; HPV: human papillomavirus.