JOURNAL of
ONCOLOGICAL
SCIENCES

REVIEW ARTICLE

Nasopharyngeal cancer in Saudi Arabia: Epidemiology and possible risk factors
Received Date : 16 May 2018
Accepted Date : 25 Jan 2019
Doi: 10.1016/j.jons.2019.01.002 - Article's Language: EN
J Oncol Sci 5 (2019) 23-30
This is an open access article under the CC BY-NC-ND license
ABSTRACT
Although, Nasopharyngeal Carcinoma (NPC) is uncommon in Arab countries, but its incidence is raising due to increased exposure to diverse risk factors. Many of the NPC-related risk factors are becoming more and more apparent in Saudi Arabia. Risk factors such as, higher antibody titers against the EBV, intake of preserved foods, tobacco smoking with alcohol consumption, family history of NPC, certain human leukocyte antigen class I genotypes, history of chronic respiratory tract conditions, exposure to different inhalants, herbal medicines, and occupational exposures are frequently encountered in Saudi population. In spite of the importance of this subject in Saudi Arabia, there is still a paucity of literature on the features and outcome of NPC in the Middle East and most Arab countries. Therefore, the objective of this review was to provide an overview of NPC and recent advances in the multidimensional understanding of this disease focusing in the available literature in epidemiology and risk factors with especial emphasis in Saudi Arabia. The previous literature was retrieved through electronic search in Medline, PubMed, Cochrane, ScienceDirect, and other electronic data base, as shown in the citation.
REFERENCES
  1. Yip TT, Ngan RK, Fong AH, Law SC. Application of circulating plasma/serum EBV DNA in the clinical management of nasopharyngeal carcinoma. Oral Oncol. 2014;50:527e538. [Crossref]  [PubMed] 
  2. Sze H, Blanchard P, Ng WT, Pignon JP, Lee AW. Chemotherapy for nasopharyngeal carcinoma-current recommendation and controversies. Hematol Oncol Clin N Am. 2015;29:1107e1122. [Crossref]  [PubMed] 
  3. Wei WI, Sham JS. Nasopharyngeal carcinoma. Lancet. 2005;365:2041e2054. [Crossref] 
  4. Chua MLK, Wee JTS, Hui EP, Chan ATC. Nasopharyngeal carcinoma. Lancet. 2016;387:1012e1024. [Crossref] 
  5. Chang ET, Adami HO. The enigmatic epidemiology of nasopharyngeal carcinoma. Cancer Epidemiol Biomark Prev. 2006;15:1765e1777. [Crossref]  [PubMed] 
  6. Nguyen-Van D, Ernberg I, Phan-Thi Phi P, Tran-Thi C, Hu L. Epstein-Barr virus genetic variation in Vietnamese patients with nasopharyngeal carcinoma: full-length analysis of LMP1. Virus Gene. 2008;37:273e281. [Crossref]  [PubMed] 
  7. Niedobitek G. Epstein-Barr virus infection in the pathogenesis of nasopharyngeal carcinoma. Mol Pathol. 2000;53:248e254. [Crossref]  [PubMed]  [PMC] 
  8. Ayadi W, Khabir A, Hadhri-Guiga B, et al. North African and Southeast Asian nasopharyngeal carcinomas: between the resemblance and the dissemblance. Bull Cancer. 2010;97:475e482. [Crossref]  [PubMed] 
  9. Chi KH, Chang YC, Guo WY, et al. A phase III study of adjuvant chemotherapy in advanced nasopharyngeal carcinoma patients. Int J Radiat Oncol Biol Phys. 2002;52:1238e1244. [Crossref] 
  10. Loyo M, Brait M, Kim MS, et al. A survey of methylated candidate tumor suppressor genes in nasopharyngeal carcinoma. Int J Canc. 2011;128: 1393e1403. [Crossref]  [PubMed]  [PMC] 
  11. Vogelstein B, Papadopoulos N, Velculescu VE, Zhou S, Diaz Jr LA, Kinzler KW. Cancer genome landscapes. Science. 2013;339:1546e1558. [Crossref]  [PubMed]  [PMC] 
  12. Laramore GE, Clubb B, Quick C, et al. Nasopharyngeal carcinoma in Saudi Arabia: a retrospective study of 166 cases treated with curative intent. Int J Radiat Oncol Biol Phys. 1988;15:1119e1127. [Crossref] 
  13. Geara FB, Nasr E, Tucker SL, et al. Nasopharyngeal cancer in the Middle East: experience of the American University of Beirut medical center. Int J Radiat Oncol Biol Phys. 2005;61:1408e1415. [Crossref]  [PubMed] 
  14. Andejani AA, Kundapur V, Malaker K. Age distribution of nasopharyngeal cancer in Saudi Arabia. Saudi Med J. 2004;25:1579e1582.
  15. El-Akkad SM, Amer MH, Lin GS, Sabbah RS, Godwin JT. Pattern of cancer in Saudi arabs referred to king faisal specialist hospital. Cancer. 1986;58: 1172e1178. [Crossref] 
  16. Al-Amro A, Al-Rajhi N, Khafaga Y, et al. Neoadjuvant chemotherapy followed by concurrent chemo-radiation therapy in locally advanced nasopharyngeal carcinoma. Int J Radiat Oncol Biol Phys. 2005;62:508e513. [Crossref]  [PubMed] 
  17. Alqadah FD, Alsafadi N, Shukla V, et al. Nasopharyngeal carcinoma (NPC) in the kingdom of Saudi Arabia. The experience of princess nourah oncology center (POC), jeddah. J Clin Oncol. 2005;23, 5597-5597. [Crossref] 
  18. Al-Wassia R, Abusanad A, Awad N, et al. Outcomes of Saudi arabian patients with nasopharyngeal cancer treated with primarily neoadjuvant chemotherapy followed by concurrent chemoradiotherapy. Journal of Global Oncology. 2016;2:123e128. [Crossref]  [PubMed]  [PMC] 
  19. Agulnik M, Epstein JB. Nasopharyngeal carcinoma: current management, future directions and dental implications. Oral Oncol. 2008;44:617e627. [Crossref]  [PubMed] 
  20. Shanmugaratnam K, Sobin LH. Histological typing of tumors of the upper respiratory tract and ear. In: Shanmugaratnam K, Sobin LH, eds. International Histological Classification of Tumors. No 19. Geneva, Switzerland: WHO-publications; 1991:32e33. [Crossref] 
  21. Reddy SP, Raslan WF, Gooneratne S, Kathuria S, Marks JE. Prognostic significance of keratinization in nasopharyngeal carcinoma. Am J Otolaryngol. 1995;16:103e108. [Crossref] 
  22. Marks JE, Phillips JL, Menck HR. The National Cancer Data Base report on the relationship of race and national origin to the histology of nasopharyngeal carcinoma. Cancer. 1998;83:582e588. [Crossref] 
  23. Yu MC, Yuan JM. Epidemiology of nasopharyngeal carcinoma. Semin Canc Biol. 2002;12:421e429. [Crossref]  [PubMed] 
  24. Tang LL, Chen WQ, Xue WQ, et al. Global trends in incidence and mortality of nasopharyngeal carcinoma. Cancer Lett. 2016;374:22e30. [Crossref]  [PubMed] 
  25. Carioli G, Negri E, Kawakita D, Garavello W, La Vecchia C, Malvezzi M. Global trends in nasopharyngeal cancer mortality since 1970 and predictions for 2020: focus on low-risk areas. Int J Canc. 2017;140:2256e2264. [Crossref]  [PubMed] 
  26. Chang ET, Adami HO. The enigmatic epidemiology of nasopharyngeal carcinoma. Cancer Epidemiol Biomark Prev. 2006;15:1765e1777. [Crossref]  [PubMed] 
  27. Bazarbashi S, Al Eid H, Minguet J. Cancer incidence in Saudi Arabia: 2012 data from the Saudi cancer registry. Asian Pac J Cancer Prev APJCP. 2017;18: 2437e2444.
  28. Al-Rajhi N, El-Sebaie M, Khafaga Y, AlZahrani A, Mohamed G, Al-Amro A. Nasopharyngeal carcinoma in Saudi Arabia: clinical presentation and diagnostic delay. East Mediterr Health J. 2009;15:1301e1307.
  29. Mahdavifara N, Ghonchehb M, Mohammadian-afshejanic A, Khosravid B, Salehiniyaef H. Epidemiology and inequality in the incidence and mortality of nasopharynx cancer in Asia. Osong Public Health Res Perspect. 2016;7: 360e372. [Crossref]  [PubMed]  [PMC] 
  30. Clubb B, Quick C, Amer M, et al. Nasopharyngeal carcinoma in Saudi Arabia: selected clinical and epidemiological aspects. Ann Saudi Med. 1990;10: 171e175. [Crossref] 
  31. Ferlay J, Ervik M, Lam F, Colombet M, Mery L, Pi~neros M, Znaor A, Soerjomataram I, Bray F. Cancer Today (powered by GLOBOCAN 2018): IARC CancerBase No. 15. http://globocan.iarc.fr. Accessed 15 March 2018.
  32. Global Health statistics. Nasopharynx Cancer in Saudi Arabia Statistics on Overall Impact and Specific Effect on Demographic Groups; 2017. http://globaldisease- burden.healthgrove.com/l/35237/Nasopharynx-Cancer-in-Saudi- Arabia. Accessed March 15, 2018.
  33. Zhang L, Zhao C, Ghimire B, et al. The role of concurrent chemoradiotherapy in the treatment of locoregionally advanced nasopharyngeal carcinoma among endemic population: a meta-analysis of the phase iii randomized trials. BMC Canc. 2010;10:558. [Crossref]  [PubMed]  [PMC] 
  34. Teo P, Yu P, Lee WY, et al. Significant prognosticators after primary radiotherapy in 903 nondisseminated nasopharyngeal carcinoma evaluated by computer tomography. Int J Radiat Oncol Biol Phys. 1996;36:291e304. [Crossref] 
  35. Kwong DL, Sham JS, Au GK, et al. Concurrent and adjuvant chemotherapy for nasopharyngeal carcinoma: a factorial study. J Clin Oncol. 2004;22: 2643e2653. [Crossref]  [PubMed] 
  36. Rossi A, Molinari R, Boracchi P, et al. Adjuvant chemotherapy with vincristine, cyclophosphamide, and doxorubicin after radiotherapy in local-regional nasopharyngeal cancer: results of a 4-year multicenter randomized study. J Clin Oncol. 1988;6:1401e1410. [Crossref]  [PubMed] 
  37. Prasad U, Wahid MI, Jalaludin MA, Abdullah BJ, Paramsothy M, Abdul- Kareem S. Long-term survival of nasopharyngeal carcinoma patients treated with adjuvant chemotherapy subsequent to conventional radical radiotherapy. Int J Radiat Oncol Biol Phys. 2002;53(3):648e655. [Crossref] 
  38. Xu L, Pan J, Wu J, et al. Factors associated with overall survival in 1706 patients with nasopharyngeal carcinoma: significance of intensive neoadjuvant chemotherapy and radiation break. Radiother Oncol. 2010;96:94e99. [Crossref]  [PubMed] 
  39. Kalaghchi B, Kazemian A, Amouzegar Hashem F, Aghili M. Chemoradiation in nasopharyngeal carcinoma: a 6-year experience in tehran cancer institute. Acta Med Iran. 2011;49:49e53.
  40. Lee AW, Lau WH, Tung SY, et al. Hong Kong Nasopharyngeal Cancer Study Group. Preliminary results of a randomized study on therapeutic gain by concurrent chemotherapy for regionally-advanced nasopharyngeal carcinoma: NPC-9901 Trial by the Hong Kong Nasopharyngeal Cancer Study Group. J Clin Oncol. 2005;23:6966e6975. [Crossref]  [PubMed] 
  41. Dechaphunkul T, Pruegsanusak K, Sangthawan D, Sunpaweravong P. Concurrent chemoradiotherapy with carboplatin followed by carboplatin and 5- fluorouracil in locally advanced nasopharyngeal carcinoma. Head Neck Oncol. 2011;3:30. [Crossref]  [PubMed]  [PMC] 
  42. Lin JC, Jan JS, Hsu CY, Liang WM, Jiang RS, Wang WY. Phase III study of concurrent chemoradiotherapy versus radiotherapy alone for advanced nasopharyngeal carcinoma: positive effect on overall and progression-free survival. J Clin Oncol. 2003;21:631e637. [Crossref]  [PubMed] 
  43. Wang J, Shi M, Hsia Y, et al. Failure patterns and survival in patients with nasopharyngeal carcinoma treated with intensity modulated radiation in Northwest China: a pilot study. Radiat Oncol. 2012;7:2. https://doi.org/ 10.1186/1748-717X-7-2. [Crossref]  [PubMed]  [PMC] 
  44. Wei WI, Sham JST. Nasopharyngeal carcinoma. Lancet. 2005;365:2041e2054. [Crossref] 
  45. Liu MT, Hsieh CY, Chang TH, Lin JP, Huang CC, Wang AY. Prognostic factors affecting the outcome of nasopharyngeal carcinoma. Jpn J Clin Oncol. 2003;33: 501e508. [Crossref]  [PubMed] 
  46. Lin S, Lu JJ, Han L, Chen Q, Pan J. Sequential chemotherapy and intensitymodulated radiation therapy in the management of locoregionally advanced nasopharyngeal carcinoma: experience of 370 consecutive cases. BMC Canc. 2010;10:39. [Crossref]  [PubMed]  [PMC] 
  47. Chang ET, Adami HO. The enigmatic epidemiology of nasopharyngeal carcinoma. Cancer Epidemiol Biomark Prev. 2006;15:1765e1777. [Crossref]  [PubMed] 
  48. Raab-Traub N. Epstein-Barr virus in the pathogenesis of NPC. Semin Canc Biol. 2002;12:431e441. [Crossref]  [PubMed] 
  49. Young LS, Dawson CW. Epstein-Barr virus and nasopharyngeal carcinoma. Chin J Canc. 2014;33:581e590. [Crossref] 
  50. Feng Fu-Tuo, Cui Qian, Liu Wen-Sheng, et al. Su-Mei Cao, Wei-Hua Jia, Jin-Xin Bei,and Yi-Xin Zeng. A single nucleotide polymorphism in the Epstein-Barr virus genome is strongly associated with a high risk of nasopharyngeal carcinoma. Chin J Canc. 2015;34:563e572. [Crossref]  [PubMed]  [PMC] 
  51. Nasrin N, Taiba K, Hannan N, Hannan M, al-Sedairy S. A molecular study of EBV DNA and p53 mutations in nasopharyngeal carcinoma of Saudi Arab patients. Cancer Lett. 1994;82:189e198. [Crossref] 
  52. Al-Kuraya K, Narayanappa R, Al-Dayel F, et al. Epstein-Barr virus infection is not the sole cause of high prevalence for Hodgkin's lymphoma in Saudi Arabia. Leuk Lymphoma. 2006;47:707e713. [Crossref]  [PubMed] 
  53. Lu SJ, Day NE, Degos L, et al. Linkage of a nasopharyngeal carcinoma susceptibility locus to the HLA region. Nature. 1990;346:470e471. [Crossref]  [PubMed] 
  54. Feng BJ, Huang W, Shugart YY, et al. Genome-wide scan for familial nasopharyngeal carcinoma reveals evidence of linkage to chromosome 4. Nat Genet. 2002;31:395e399. [Crossref]  [PubMed] 
  55. Xiong W, Zeng ZY, Xia JH, et al. A susceptibility locus at chromosome 3p21 linked to familial nasopharyngeal carcinoma. Cancer Res. 2004;64: 1972e1974.
  56. Hu LF, Qiu QH, Fu SM, et al. A genome-wide scan suggests a susceptibility locus on 5p 13 for nasopharyngeal carcinoma. Eur J Hum Genet. 2008;16: 343e349. [Crossref]  [PubMed] 
  57. Hirschhorn JN, Daly MJ. Genome-wide association studies for common diseases and complex traits. Nat Rev Genet. 2005;6:95e108. [Crossref]  [PubMed] 
  58. Tse KP, Su WH, Yang ML, et al. A gender-specific association of CNV at 6p21.3 with NPC susceptibility. Hum Mol Genet. 2011;20:2889e2896. [Crossref]  [PubMed]  [PMC] 
  59. JX1 Bei, Li Y, Jia WH, et al. A genome-wide association study of nasopharyngeal carcinoma identifies three new susceptibility loci. Nat Genet. 2010;42: 599e603. [Crossref]  [PubMed] 
  60. Ng CC, Yew PY, Puah SM, et al. A genome-wide association study identifies ITGA9 conferring risk of nasopharyngeal carcinoma. J Hum Genet. 2009;54: 392e397. [Crossref]  [PubMed] 
  61. Tse KP, Su WH, Chang KP, et al. Genome-wide association study reveals multiple nasopharyngeal carcinoma-associated loci within the HLA region at chromosome 6p21.3. Am J Hum Genet. 2009;85:194e203. [Crossref]  [PubMed]  [PMC] 
  62. Bei JX, Jia WH, Zeng YX. Familial and large-scale case-control studies identify genes associated with nasopharyngeal carcinoma. Semin Canc Biol. 2012;22: 96e106. [Crossref]  [PubMed] 
  63. Mocellin S, Verdi D, Pooley KA, et al. Telomerase reverse transcriptase locus polymorphisms and cancer risk: a field synopsis and meta-analysis. J Natl Cancer Inst. 2012;104:840e854. [Crossref]  [PubMed]  [PMC] 
  64. Rafnar T, Sulem P, Stacey SN, et al. Sequence variants at the TERT-CLPTM1L locus associate with many cancer types. Nat Genet. 2009;41:221e227.
  65. Yee Ko JM, Dai W, Wun Wong EH, et al. Multigene pathway-based analyses identify nasopharyngeal carcinoma risk associations for cumulative adverse effects of TERT-CLPTM1L and DNA double-strand breaks repair. Int J Canc. 2014;135:1634e1645. [Crossref]  [PubMed] 
  66. Barbu A, Jansson L, Sandberg M, Quach M, Palm F. The use of hydrogen gas clearance for blood flow measurements in single endogenous and transplanted pancreatic islets. Microvasc Res. 2015;97:124e129. [Crossref]  [PubMed] 
  67. Liu RR, Chen JC, Li MD, Li T, Tan Y, Zhang M. A meta-analysis of glutathione Stransferase M1 and T1 genetic polymorphism in relation to susceptibility to nasopharyngeal carcinoma. Int J Clin Exp Med. 2015;8:10626e10632.
  68. Chang ET, Adami HO. The enigmatic epidemiology of nasopharyngeal carcinoma. Cancer Epidemiol Biomark Prev. 2006;15:1765e1777. [Crossref]  [PubMed] 
  69. Yu MC, Yuan JM. Epidemiology of nasopharyngeal carcinoma. Semin Canc Biol. 2002;12:421e429. [Crossref]  [PubMed] 
  70. Wee JT, Ha TC, Loong SL, Qian CN. Is nasopharyngeal cancer really a "Cantonese cancer"? Chin J Canc. 2010;29:517e526. [Crossref]  [PubMed] 
  71. Simons MJ. Nasopharyngeal carcinoma as a paradigm of cancer genetics. Chin J Canc. 2011;30:79e84. [Crossref]  [PubMed]  [PMC] 
  72. American Cancer Society. Global Cancer Facts and Figures. second ed. Atlanta, GA: American Cancer Society; 2011. https://oralcancerfoundation.org/wpcontent/ uploads/2016/03/acspc-027766.pdf. Accessed March , 2018.
  73. Xue W-Q, Qin H-D, Ruan H-L, Shugart YY, Jia W-H. Quantitative association of tobacco smoking with the risk of nasopharyngeal carcinoma: a comprehensive meta-analysis of studies conducted between 1979 and 2011. Am J Epidemiol. 2013;178:325e338. [Crossref]  [PubMed]  [PMC] 
  74. Algorinees RM, Alreshidi IG, Alateeq MF, et al. Prevalence of cigarette smoking usage among adolescent students in northern Saudi Arabia. Asian Pac J Cancer Prev APJCP. 2016;17:3839e3843.
  75. Polesel J, Franceschi S, Talamini R, et al. Tobacco smoking, alcohol drinking, and the risk of different histological types of nasopharyngeal cancer in a lowrisk population. Oral Oncol. 2011;47:541e545. [Crossref]  [PubMed] 
  76. Ren ZF, Liu WS, Qin HD, et al. Effect of family history of cancers and environmental factors on risk of nasopharyngeal carcinoma in Guangdong, China. Cancer Epidemiol. 2010;34:419e424. [Crossref]  [PubMed] 
  77. OuYang PY, Su Z, Mao YP, Liang XX, Liu Q, Xie FY. Prognostic impact of family history in southern Chinese patients with undifferentiated nasopharyngeal carcinoma. Br J Canc. 2013;109:788e794. [Crossref]  [PubMed]  [PMC] 
  78. Ung A, Chen CJ, Levine PH, et al. Familial and sporadic cases of nasopharyngeal carcinoma in Taiwan. Anticancer Res. 1999;19:661e665.
  79. Cao SM, Guo X, Li NW, Xiang YQ, Hong MH, Min HQ. Clinical analysis of 1,142hospitalized Cantonese patients with nasopharyngeal carcinoma. Ai Zheng. 2006;25:204e208.
  80. Hsu WL, Yu KJ, Chien YC, et al. Familial tendency and risk of nasopharyngeal carcinoma in taiwan: effects of covariates on risk. Am J Epidemiol. 2011;173: 292e299. [Crossref]  [PubMed]  [PMC] 
  81. Ho JH. Nasopharyngeal carcinoma in Hong Kong. In: Muir CS, Shanmugaratnam K, eds. Cancer of the Nasopharynx. Copenhagen: Munksgaard; 1967:58e63.
  82. ARC Monographs on the Evaluation of Carcinogenic Risks to Humans. No. 100E. IARC Working Group on the Evaluation of Carcinogenic Risk to Humans. Lyon (FR): International Agency for Research on Cancer; 2012. Accessed April 2018 http://publications.iarc.fr/Book-And-Report-Series/Iarc-Monographs- On-The-Evaluation-Of-Carcinogenic-Risks-To-Humans.
  83. Henderson BE, Louie E. Discussion of risk factors for nasopharyngeal carcinoma. IARC Sci Publ. 1978:251e260.
  84. Zou J, Sun Q, Akiba S, et al. A case-control study of nasopharyngeal carcinoma in the high background radiation areas of Yangjiang, China. J Radiat Res. 2000;41:53e62. [Crossref]  [PubMed] 
  85. Sriamporn S, Vatanasapt V, Pisani P, Yongchaiyudha S, Rungpitarangsri V. Environmental risk factors for nasopharyngeal carcinoma: a case-control study in northeastern Thailand. Cancer Epidemiol Biomark Prev. 1992;1: 345e348.
  86. Gallicchio L, Matanoski G, Tao XG, et al. Adulthood consumption of preserved and nonpreserved vegetables and the risk of nasopharyngeal carcinoma: a systematic review. Int J Canc. 2006;119:1125e1135. [Crossref]  [PubMed] 
  87. Poirier S, Hubert A, de-The G, Ohshima H, Bourgade MC, Bartsch H. Occurrence of volatile nitrosamines in food samples collected in three high-risk areas for nasopharyngeal carcinoma. IARC Sci Publ. 1987;415e9. [Crossref] 
  88. IARC. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. Volume 56: Some Naturally Occurring Substances: Food Items and Constituents, Heterocyclic Aromatic Amines and Mycotoxins. Lyon: IARC Press; 1993. https:// monographs.iarc.fr/iarc-monographs-on-the-evaluation-of-carcinogenicrisks- to-humans-65/. Accessed March , 2018.
  89. Shah JP, Lydiatt W. Treatment of cancer of the head and neck. CA - Cancer J Clin. 1995;45:352e368. [Crossref]  [PubMed] 
  90. Shaw R, Beasley N. Aetiology and risk factors for head and neck cancer: United Kingdom National Multidisciplinary Guidelines. J Laryngol Otol. 2016;130: S9eS12. [Crossref]  [PubMed]  [PMC] 
  91. Yu IT, Chiu YL, Wong TW, Tang JL. Deaths from nasopharyngeal cancer among waiters and waitresses in Chinese restaurants. Int Arch Occup Environ Health. 2004;77:499e504. [Crossref]  [PubMed] 
  92. Geser A, Charnay N, Day NE, de The G, Ho HC. Environmental factors in the etiology of nasopharyngeal carcinoma: report on a case-control study in Hong Kong. IARC Sci Publ. 1978:213e229.
  93. Laouamri S, Hamdi-Cherif M, Sekfali N, Mokhtari L, Kharchi R. Dietary risk factors of nasopharyngeal carcinoma in the Setif area in Algeria. Rev Epidemiol Sante Publique. 2001;49:145e156.
  94. Yu IT, Chiu YL, Wong TW, Tang JL. Deaths from nasopharyngeal cancer among waiters and waitresses in Chinese restaurants. Int Arch Occup Environ Health. 2004;77:499e504. [Crossref]  [PubMed] 
  95. Altayep KM, Ahmed HG, a Tallaa AT, Alzayed AS, Alshammari AJ, Ali Talla AT. Epidemiology and clinical complication patterns of influenza a (H1N1 virus) in northern Saudi Arabia. Infect Dis Rep. 2017;9:6930. [Crossref]  [PubMed]  [PMC] 
  96. Yu MC, Huang TB, Henderson BE. Diet and nasopharyngeal carcinoma: a casecontrol study in Guangzhou, China. Int J Canc. 1989;43:1077e1082. [Crossref]  [PubMed] 
  97. Ning JP, Yu MC, Wang QS, Henderson BE. Consumption of salted fish and other risk factors for nasopharyngeal carcinoma (NPC) in Tianjin, a low-risk region for NPC in the People's Republic of China. J Natl Cancer Inst. 1990;82:291e296. [Crossref]  [PubMed] 
  98. Chang Ellen T, Adami Hans-Olov. The enigmatic epidemiology of nasopharyngeal carcinoma. Cancer Epidemiol Biomark Prev. 2006;15:1765e1777. [Crossref]  [PubMed] 
  99. Potter JD, Steinmetz K. Vegetables, fruit and phytoestrogens as preventive agents. IARC Sci Publ. 1996:61e90.
  100. Zeng Y, Zhong JM, Mo YK, Miao XC. Epstein-Barr virus early antigen induction in Raji cells by Chinese medicinal herbs. Intervirology. 1983;19:201e204. [Crossref]  [PubMed] 
  101. Ahmed HG, Alosayfir MAS, Almuzaini FKF, Alateeq MFM, Alrasheedi AO. Traditional herbal and N on-steroidal anti-inflammatory analgesic (nsaias ) usage and its association with chronic kidney disease(CKD) in northern Saudi Arabia. MOJ Public Health. 2017;5, 0 0113 https://doi.org/10.15406/mojph.2. 017.05.001.13. [Crossref] 
  102. Shanmugaratnam K, Higginson J. Aetiology of NPC. In: Muir CS, Shanmugaratnam K, eds. Cancer of the Nasopharynx. UICC Monograph Series 1. Munksgaard (Copenhagen, Denmark). Union Internationale Contre le Cancer; 1967:130e134.
  103. Hildesheim A, Dosemeci M, Chan CC, et al. Occupational exposure to wood, formaldehyde, and solvents and risk of nasopharyngeal carcinoma. Cancer Epidemiol Biomark Prev. 2001;10:1145e1153.
  104. Henderson BE, Louie E, SooHoo Jing J, Buell P, Gardner MB. Risk factors associated with nasopharyngeal carcinoma. N Engl J Med. 1976;295: 1101e1106. [Crossref]  [PubMed] 
  105. Bei JX, Li Y, Jia WH, et al. A genome-wide association study of nasopharyngeal carcinoma identifies three new susceptibility loci. Nat Genet. 2010;42: 599e603. [Crossref]  [PubMed] 
  106. Ruan HL, Qin HD, Shugart YY, et al. Developing genetic epidemiological models to predict risk for nasopharyngeal carcinoma in high-risk population of China. PLoS One. 2013;8, e56128. [Crossref]  [PubMed]  [PMC] 
  107. Feng FT, Cui Qian, Liu Wen-Sheng, et al. A single nucleotide polymorphism in the Epstein-Barr virus genome is strongly associated with a high risk of nasopharyngeal carcinoma. Chin J Canc. 2015;34:563e572. [Crossref]  [PubMed]  [PMC] 
  108. Bei JX, Zuo XY, Liu WS, Guo YM, Zeng YX. Genetic susceptibility to the endemic form of NPC. Chin Clin Oncol. 2016;5:15. [Crossref]  [PubMed] 
  109. IARC Working Group on the Evaluation of Carcinogenic Risks to Humans. Biological agents. Volume 100 B. A review of human carcinogens. IARC Monogr Eval Carcinog Risks Hum. 2012;100(Pt B):1e441.
  110. Selitsky SR, Marron D, Mose LE, Parker JS, Dittmer DP. Epstein-barr viruspositive cancers show altered B-cell clonality. mSystems. 2018;3. e00081-18. [Crossref]  [PubMed]  [PMC] 
  111. Song P, Yin SC. Long non-coding RNA 319 facilitates nasopharyngeal carcinoma carcinogenesis through regulation of miR-1207-5p/KLF12 axis. Gene. 2019;680:51e58. [Crossref]  [PubMed]