|
| GUIDELINES | | | Year : 2008 | Volume : 3 | Issue : 6 | Page : 65-67 | | | Epidemiology of lung cancer | | | Yasser Bahader1, Abdul-Rahman Jazieh2
1 King Faisal Specialist and Research Center, Riyadh, Saudi Arabia
2 King Abdulaziz Medical City for National Guard, Riyadh, Saudi Arabia
Correspondence Address:
Abdul-Rahman Jazieh
Department of Oncology (Mail code 1777), King Abdulaziz Medical City for National Guard, P.O. Box 22490, Riyadh 11426
Saudi Arabia
| |  Abstract | | | Lung cancer ranks first in the world in incidence and mortality. Multiple risk factors have been identified and the majority of lung cancer cases are preventable.
This manuscript presents a summary of the epidemiology of lung cancer and the risk factors.
Keywords: Lung cancer, epidemiology, risk factors
How to cite this article:
Bahader Y, Jazieh AR. Epidemiology of lung cancer. Ann Thorac Med 2008;3:65-7 |
Lung cancer is the most common cancer worldwide (1.35 million of 10.9 million of new cases) and the deadliest cancer (1.18 million of 6.7 million cancer-related deaths). [1]
As per the Saudi National Cancer Registry 2003 statistics, there were 242 cases of lung cancer accounting for 3.7 % of all diagnosed cases. [2] Lung cancer ranked fifth among the male population and 15th among the female population. It affected 183 (75.6%) males and 59 (24.4%) females, with a male to female ratio of 3:1. The overall Adjusted Standard Rate (ASR) was 3.1/100,000. The ASR was 4.7/100,000 for males and 1.4/100,000 for females, which is much less than the international figures. For example, ASR in the United States is 87/100,000 for males and 54.4/100,000 for females. The mean age at diagnosis was 64 years among males (range 24-98 years) and 61 years among females (range 24 - 89 years). The most common morphological subtypes are squamous cell carcinoma, adenocarcinoma and small cell carcinoma, which accounted for 25, 23 and 13%, respectively. Stage distribution showed that 54.5% had distant metastasis at presentation, and localized disease, regional and unknown represent 17.4, 14.5 and 13.6%, respectively.
| Risk Factors for Lung Cancer | |  |
Smoking
The rapid increase of lung cancer over the last century from a rare disease to an epidemic is attributed to the exposure to newly introduced major risk factors, which includes smoking at the top of the list.
Around 85 - 90% of lung cancer could be attributed to the use of tobacco directly or indirectly. [3]
The relative risk of dying from lung cancer is 11 - 20 times more in smokers compared with nonsmokers. The risk of lung cancer is dependent on the number of cigarettes smoked per day (calculated by pack/year number) and the duration of smoking, with an increase in the risk of smoking started at a younger age. [4],[5],[6]
The environmental tobacco exposure (ETS), which may be referred to as 'second-hand smoking,' increases the risk by 27-80%. [7],[8],[9],[10] ETS may occur at home or at work. For example, the risk of nonsmoker spouse increases by 20 - 30% if the spouse is a smoker over a nonsmoker's spouse. [11] About 25% of the lung cancer in nonsmoker is attributed to second-hand smoking, which constitutes about 5% of all lung cancer cases.
Smoking cessation at any age is of proven benefits of reduction of lung cancer risk over an extended period of time (15-20 years), but it remains higher than never-smoker risk. [7],[12],[13],[14]
Radon gas
The exposure to radon is an established risk factor of lung cancer, which was initially observed in uranium miners. [15],[16] However, this naturally occurring radioactive gas accumulates also in buildings and homes, especially in basements and lower-level floors.
The exposure to the indoor radon may be responsible for up to 9% if lung cancer in Western countries as it has a synergistic effect with smoking. Smoking in minors increases the risk of lung cancer by 10 times over the nonsmoker minors. [17]
Industrial and occupational exposure
Exposure to various carcinogens has been linked to lung cancer. The list of these carcinogens includes arsenic, polycyclic hydrocarbons, diesel exhaust, herbicides and insecticides, silica, asbestos, beryllium and chromium. Asbestos is a well known cause of not only mesothelioma but also of primary lung cancer. The risk of exposure to asbestos is about five times more than the general population, but when it is combined with smoking, a synergetic effect takes place and increases the risk up to 50 - 100 times. The incidence peak of cancer occurs 25 - 30 years after exposure. [18],[19],[20],[21]
Air pollution
Exposure to outdoor pollution, especially nitrogen oxides from the traffic fumes, has been linked to an increase risk of lung cancer. [8],[22]
| Other Risk Factors | | |
There are other risk factors that were associated with an increase in the incidence of lung cancer, including family history, sedentary life, alcohol and dietary factors, with a variable strength of association. [23],[24],[25],[26]
Pathology
Lung cancer is divided into non small cell lung cancer (>80% of cases) and small cell lung cancer. The non small cell lung cancer is divided into adenocarcinoma, squamous cell and large cell carcinoma.
There was a shift in the incidence of squamous cell carcinoma and adenocarcinoma. Up to the late 1980s, squamous cell lung cancer was the most common subtype, which was then surpassed by adenocarcinoma.
It is note worthy that the risk of all of these subtypes of cancer is increased by smoking.
Prevention
As mentioned earlier, smoking cessation and eliminating the risk of tobacco will eradicate the majority of lung cancer cases, making it one of the most preventable cancers. [7],[14],[27] Minimizing the occupational exposure to the above-mentioned carcinogens will decrease the risk further.
Early detection
Various studies using chest X-ray, sputum cytology and spinal computed tomography (CT) scans were not supportive of routine mass screening. [28],[29],[30] A large multisite NCI-USA sponsored study of spinal CT scan including more than 50,000 participants may help answer this question.
| Conclusion | | |
While lung cancer is the leading cancer in incidence and mortality, it is also a preventable disease in the majority of cases.
| References | | |
| 1. | Parkin D, Bray F, et al . Global cancer statistics 2002. Ca Cancer J 2005;55:74-108.  | | 2. | National Cancer Registry. Kingdom of Saudi Arabia: 2003. | | 3. | Shopland D. Tobacco use and its contribution to early cancer mortality with a special emphasis on cigarette smoking. Environ Health prospect 1995;103:131-42. | | 4. | Doll R, Peto R, Boreham J, Sutherland I. Mortality from cancer in relation to smoking: 50 years observations on British doctors. Br J Cancer 2005;92:426-9. [PUBMED] [FULLTEXT] | | 5. | Doll R, Peto R. Cigarette smoking and brochial carcinoma: Dose and time relationships among regular smokers and lifelong non-smokers. J Epidemiol Community Health 1978;32:303-13. [PUBMED] [FULLTEXT] | | 6. | Wiencke JK, Thurston SW, Kelsey KT, Varkonyi A, Wain JC, Mark EJ, et al . Early age at smoking initiation and tobacco carcinogen DNA damage in the lung. J Natl Cancer Inst 1999;91:614-9. [PUBMED] [FULLTEXT] | | 7. | Crispo A, Brennan P, Jockel KH, Schaffrath-Rosario A, Wichmann HE, Nyberg F, et al . The cumulative risk of lung cancer among current, ex- and never-smokers in European men. Br J Cancer 2004;91:1280-6. | | 8. | Vineis P, Airoldi L, Veglia F, Olgiati L, Pastorelli R, Autrup H, et al . Environmental tobacco smoke and risk of respiratory cancer and chronic obstructive pulmonary disease in former smokers and never smokers in the EPIC prospective study. BMJ 2005;330:227. | | 9. | Wen W, Shu XO, Gao YT, Yang G, Li Q, Li H, et al . Environmental tobacco smoke and mortality in Chinese women who have never smoked: Prospective cohort study. BMY 2006;333:376. | | 10. | Miller DP, De Vivo I, Neuberg D, Wain JC, Lynch TJ, Su L, et al . Association between sel-reported environmental tobacco smoke exposure and lung cancer: Modification by GSTP1 polymorphism. Int J Cancer 2003;104:758-63. [PUBMED] [FULLTEXT] | | 11. | Alberg AJ, Samet JM. Epidemiology of lung cancer. Chest 2003;123:21S-49S. [PUBMED] [FULLTEXT] | | 12. | Halpern MT, Gillespie BW, Warner KE. Patterns of absolute risk of lung cancer mortality in former smokers. J Natl Cancer Inst 1993;85:457-64. [PUBMED] [FULLTEXT] | | 13. | Kawachi I, Colditz GA, Stampfer MJ, Willett WC, Manson JE, Rosner B, et al . Smoking cessation in relation to total mortality rates in women: A prospective cohort study. Ann Intern Med 1993;119:992-1000. [PUBMED] [FULLTEXT] | | 14. | Peto R, Darby S, Deo H, Silcocks P, Whitley E, Doll R. Smoking, smoking cessation and lung cancer in UK since 1950: Combination of national statistics with two case-control studies. BMJ 2000;321:323-9. [PUBMED] [FULLTEXT] | | 15. | IARC. Ionizing radiation, part 2: Some internally deposited radionuclides. Views and expert opinions of an IARC working group on the evaluation of carcinogenic risks to human. Lyon, 14 - 21 June 2000. IARC Monogr Eval Carcinog Risks Hum 2001;78:1-559. | | 16. | Frumkin H, Samet JM. Radon. CA Cancer J Clin 2000;51:337-44. | | 17. | Darby S, Hill D, Auvinen A, © Barros-Dios JM, Baysson H, Bochicchio F, et al . Radon in homes and risk of lung cancer: Collaborative analysis of individual data from 13 European case-control studies. BMJ 2005;330:223. | | 18. | Chen TM, Kuschner WG. Non-tobacco related lung carcinogens. Lung cancer principle and practice. In: Harvey P, et al , editors. 3rd ed, Lippincot Williams and Wilkins; 2005. p. 61-73. | | 19. | Lee PN. Relation between exposure to asbestos and smoking jointly and the risk of lung cancer. Occup Environ Med 2001;58:145-53. [PUBMED] [FULLTEXT] | | 20. | Lidell FD. The interaction of asbestos and smoking in lung cancer. Ann Occup Hyg 2001;45:341-56. | | 21. | Berry G, Lidell FD. The interaction of asbestos and smoking in lung cancer: A modified measure of effect. Ann Occup Hyg 2004;48:459-62. | | 22. | Nafstad P, Haheim LL, Wisloff T, Gram F, Oftedal B, Holme I, et al . Urban air pollution and mortality in a cohort Norwegian men. Environ Health Perspect 2004;112:610-5. | | 23. | Nitadori J, Inoue M, Iwasaki M, Otani T, Sasazuki S, Nagai K, et al . Association between lung cancer incidence and family history of lung cancer: Data from a large-scale population-based cohort study, the JPHC study. Chest 2006;130:968-75. [PUBMED] [FULLTEXT] | | 24. | Freudenheim JL, Ritz J, Smith-Warner SA, Albanes D, Bandera EV, van den Brandt PA, et al . Alcohol consumption and risk of lung cancer: A pooled analysis of cohort studies. Am J Clin Nutr 2005;82:657-67. [PUBMED] [FULLTEXT] | | 25. | Liu Y, Sobue T, Otani T, Tsugane S. Vegetables, fruit consumption and risk of lung cancer among middle-aged Japanese men and women: JPHC study. Cancer Causes Control 2004;15:349-57. [PUBMED] [FULLTEXT] | | 26. | Tardon A, Lee WJ, Delgado-Rodriguez M, Dosemeci M, Albanes D, Hoover R, et al . Leisure-time physical activity and lung cancer: A meta-analysis. Cancer Causes Control 2005;16:389-97. [PUBMED] [FULLTEXT] | | 27. | Ebbert JO, Yang P, Vachon CM, Vierkant RA, Cerhan JR, Folsom AR, et al . Lung cancer risk reduction after smoking cessation: Observations from a prospective cohort of women. J Clin Oncol 2003;21:921-6. [PUBMED] [FULLTEXT] | | 28. | Bach PB, Kelley MJ, Tate RC, McCrory DC. Screening for lung cancer: A review of the literature. Chest 2003;123:72S-82S. [PUBMED] [FULLTEXT] | | 29. | Henschke CI, McCauley DI, Yahkelvitz DF, Naidich DP, McGuinness G, Miettinen OS, et al . Early Lung Cancer Action Project: Overall design and findings from baseline screening. Lancet 1999;354:99-105. | | 30. | Swensen SJ, Jett JR, Sloan JA, Midthun DE, Hartman TE, Sykes AM, et al . Screening for lung cancer with low-dose spiral computed tomography. Am J Resp Crit Care Med 2002;165:508-13. [PUBMED] [FULLTEXT] |
| |
| This article has been cited by | | 1 | Comparison study of clinicoradiological profile of primary lung cancer cases: An Eastern India experience | | | Dey, A. and Biswas, D. and Saha, S.K. and Kundu, S. and Kundu, S. and Sengupta, A. | | Indian Journal of Cancer. 2012; 49(1): 89-95 | | [Pubmed] | | | 2 | Lung cancer incidence in the Arab league countries: Risk factors and control | | | Salim, E.I. and Jazieh, A.R. and Moore, M.A. | | Asian Pacific Journal of Cancer Prevention. 2011; 12(1): 17-34 | | [Pubmed] | | | 3 | Prognosis and resuscitation status of critically ill patients with lung cancer admitted to the intensive care unit | | | Aldawood, A.S. | | Anaesthesia and Intensive Care. 2010; 38(5): 920-923 | | [Pubmed] | | | 4 | Lung cancer at a university hospital in Saudi Arabia: A four-year prospective study of clinical, pathological, radiological, bronchoscopic, and biochemical parameters | | | Alamoudi, O.S. | | Annals of Thoracic Medicine. 2010; 5(1): 30-36 | | [Pubmed] | |
| | | | |   | | | | | |
| Article Access Statistics | | | Viewed | 3594 | | | Printed | 130 | | | Emailed | 4 | | | PDF Downloaded | 569 | | | Comments | [Add] | | | Cited by others | 4 | | | | 
|
