Thoracic Cancer ISSN 1759-7706
ORIGINAL ARTICLE
Detection rate of lung cancer among chronic obstructive pulmonary disease patients regularly followed up by pulmonary physicians tca_56
1
179..182
2
Tanel Laisaar , Hille Lill , Anneli Kullamaa2 & Rain Jõgi2 1 Department of Thoracic Surgery, Tartu University Hospital, Tartu, Estonia 2 Department of Pneumology, Tartu University Hospital, Tartu, Estonia
Keywords Chronic obstructive pulmonary disease; incidence; lung cancer; smoking. Correspondence Tanel Laisaar, Department of Thoracic Surgery, Tartu University Hospital, Puusepa 8, 51014 Tartu, Estonia. Tel: +372 7 318 937 Fax: +372 7 318 937 E-mail: [email protected] Received: 5 May 2011; accepted: 26 May 2011. doi: 10.1111/j.1759-7714.2011.00056.x
Abstract Background: Chronic obstructive pulmonary disease (COPD) has been found to be an independent risk factor for lung cancer. The aim of this study was to evaluate whether regular follow up of COPD patients increases the diagnosis of lung cancer at an early stage. Methods: Case reports of 105 male moderate to severe COPD patients who participated in a clinical study were analyzed retrospectively. Throughout the 3-year study period patients regularly visited a pulmonary physician. Investigations to detect lung cancer were ordered only with the presence of symptoms. The lung cancer incidence in the study group was compared to that of general male population matched by age. Results: At the beginning of the study the mean age was 67 (range 55–81) years, mean smoking history 36.2 (range 11–102) years and mean forced expiratory volume in 1 s (FEV1) 43.3% (range 22.7–59.7). During the study six lung cancers and five other cancers were diagnosed per 287 person-years of observation. Only one lung cancer was operable, others were locally advanced or had distant metastases. Conclusions: Despite the patients being followed up regularly by a pulmonary physician, most cancers were diagnosed at an advanced stage. The relative risk of getting lung cancer was 6.0 times higher (95% CI 2.7–13.3) among COPD patients than among the general population. The current study confirms that COPD patients have an increased risk of lung cancer. Moreover simple regular follow up of patients without special lung cancer screening investigations do not help to detect the cancer in its early stage. This study stresses the need to establish a more detailed follow-up program for COPD patients to detect early lung cancer in this high risk population.
Introduction Lung cancer is the leading cause of cancer death among men and in several countries also among women.1 A major problem in lung cancer management is late detection which reduces the possibilities of curative treatment and often eliminates surgery as the most effective treatment modality. Only 16–20% of lung cancers are diagnosed early enough to be surgically removed.2 Lung cancer has several risk factors; the most important one is smoking, which is also a known risk factor for chronic obstructive pulmonary disease (COPD). In addition COPD
has been found to be an independent risk factor for lung cancer. It has been demonstrated in several studies,3–12 and recently one meta-analysis showed that, independent of cigarette smoking history, reduced forced expiratory volume in 1 s (FEV1) increases the risk of lung cancer in the general population.13 Most COPD patients frequently visit their physician due to exacerbation or complications of the disease. Whether such follow up of patients increases the diagnosis of early stage lung cancer is not known. The aim of the current study was to evaluate the detection rate of lung cancer by stage at the time of diagnosis among COPD patients who regularly visit a pulmonary physician.
Thoracic Cancer 2 (2011) 179–182 © Tianjin Lung Cancer Institute and Blackwell Publishing Asia Pty. Ltd
179
Detection of lung cancer in COPD patients
T. Laisaar et al.
Table 1 Distribution of cancers diagnosed during the study period in chronic obstructive pulmonary disease patients
Case reports of 105 male moderate to severe COPD patients over 54 years of age who participated in a clinical study during the years 2000 to 2004 were analyzed retrospectively. At the beginning of the study chest radiograph was performed on all patients to exclude lung cancer. Throughout the 3-year study period, patients visited a pulmonary physician every 3 months. Patient history was obtained and lung auscultation, blood pressure measurement, and spirometry were performed at every visit; electrocardiogram was performed and a St. George respiratory questionnaire was filled out every second visit. Investigations to detect lung cancer were ordered only in the case of symptoms. No chest radiograph or computed tomography (CT) scan was done as part of the clinical study; however physicians were free to order these or other investigations in the case of suspicion of any concomitant disease, including lung cancer, arising. Lung cancer incidence in the study group was compared to that in the general male population matched by age. Data of cancer incidence in the general population was obtained from the National Cancer Registry. Summary statistics were used to describe the study population. Mean and range (min and max) were used for continuous variables; relative risk with a 95% confidence interval was used to compare the incidence of lung cancer in the study group to the respective incidence in the general male population of the same age. The current study was accepted by the institutional ethics committee and was performed in accordance with the ethical standards according to Declaration of Helsinki.
Results All patients were male. At the beginning of the study the mean age of the study subjects was 67 years (range 55–81 years). Sixty-eight patients were smokers and 37 were ex-smokers. Mean smoking history was 36.2 (range 11–102) pack years and the mean FEV1 was 43.3% (range 22.7–59.7%). During the study period of 3 years six primary lung cancers and five other cancers were diagnosed per 287 person-years of observation (Table 1). Only one lung cancer was operable (pT2N0M0 – stage Ib), others were locally advanced (one case) or with distant metastases (four cases) at the time of diagnosis. The morphological distribution of lung cancers is shown in Table 1. Lung cancer incidence was six cases per 287 person-years (2.1%) in the study group and 347 per 100 000 person years (0.35%) in the reference group (Estonian male population of the same age). The relative risk of getting lung cancer was 6.0 times higher (95% CI 2.7–13.3; P < 0.0001) among COPD patients compared to the general population (Fig 1). 180
Lung cancer Squamous cell carcinoma Small cell carcinoma Unknown Prostate cancer Laryngeal cancer Stomach cancer Colon cancer Total
6 4 1 1 2 1 1 1 11
Discussion Both COPD and lung cancer are challenging problems for a pulmonary physician, especially when combined in one patient. Several previous studies have documented that reduced FEV1 is associated with an increased risk of lung cancer.3–14 In most studies, however, only respiratory function was measured and COPD was not constantly diagnosed.5–10 We included only patients with a diagnosis of moderate or severe COPD, according to the diagnostic criteria of the Global Initiative for Chronic Obstructive Lung Disease (GOLD; based on the April 1998 Meeting Guidelines).15 Similar to previous studies, our data indicated that patients with COPD were at higher risk of developing lung cancer compared to the general population. According to a study by Mannino et al. moderate to severe COPD also increases the risk of lung cancer when compared to mild obstructive lung disease.3 It has also been documented that the percentage of predicted FEV1 is inversely related to lung cancer risk.7,14 Apart from lung cancer, decline in FEV1 is a major indicator of mortality risk for a wide range of diseases, including ischemic heart disease, stroke and other respiratory diseases.16
2.50 Lung cancer risk (%)
Materials
2.00 1.50 1.00 0.50 0.00
Estonian population
COPD patients
Figure 1 Lung cancer risk in study group (2.1%) compared to Estonian male population matched by age (0.35%). COPD, chronic obstructive pulmonary disease.
Thoracic Cancer 2 (2011) 179–182 © Tianjin Lung Cancer Institute and Blackwell Publishing Asia Pty. Ltd
T. Laisaar et al.
Various suggestions have been made to explain the relationship between COPD and lung cancer. Probably one of the most important contributors is the common risk factor, smoking. In our study group we diagnosed squamous cell carcinoma in four patients, which is related to smoking more than other morphological types of lung cancer.17 No adenocarcinoma was found among our patients, although it is an equally common or even a more frequent type of lung cancer according to recent epidemiological lung cancer studies.18 Despite the limited number of patients in our study, we seemed to demonstrate the trend of an especially high incidence of smoking-related squamous cell carcinoma in COPD patients. A similar finding of COPD increasing the risk of squamous cell carcinoma in patients with surgically resectable NSCLC has been recently published by Papi et al.19 One limitation of our study is the difference in smoking prevalence in the study group and the reference group. However, the percentage of smokers among Estonian men was as high as 44.1% in the year 2000, on top of ex-smokers whose numbers are not included.20 Taking into account previous similar studies,3,6–8,10–12 we can assume that the higher incidence of lung cancer in our study group is an independent finding and not only related to the higher prevalence of smoking. In our study COPD was diagnosed according to the GOLD criteria; we did not evaluate the severity of emphysema. Some recent data suggest that emphysema, evaluated by CT scan, like airflow obstruction, might be an independent risk factor for lung cancer.12,21 All study subjects were regularly followed up by a pulmonary physician, although no routine chest radiograph and CT scan was performed during the study period. Investigations were ordered only when patients had specific symptoms of lung cancer or other concomitant disease. Unfortunately early stage lung cancer has almost no specific symptoms, which explains the fact that only one out of six lung cancers was diagnosed at an early stage and could be treated surgically. Hamilton et al. demonstrated that the most common lung cancer symptom is cough; other specific symptoms are loss of appetite, loss of weight, dyspnea, chest pain and fatigue.22 The most specific lung cancer symptom in their study was hemoptysis, however this rarely occurs.22 All these symptoms can also be present in a patient with COPD, even hemoptysis at the time of exacerbation. Very similar symptomatology makes the diagnostics of lung cancer in a COPD patient especially difficult. Up to 20% of lung cancers are generally diagnosed in an operable stage,2 a similar percentage to our small study. These data demonstrate that regular clinical follow up, even by a pulmonary specialist, is not enough to improve lung cancer diagnostics. Routine screening for lung cancer, especially in high risk populations, could be the solution for diagnosing
Detection of lung cancer in COPD patients
more early stage lung cancers and potentially improving overall survival. A recent systematic literature review of lung cancer screening studies by Black et al. demonstrated that CT screening allows diagnosis of a high proportion of stage I lung cancer, even 100% in some studies.23 In summary our study demonstrated 6.0 times higher relative risk of lung cancer among COPD patients compared to that of general population. More importantly, despite regular follow up of patients, we were able to diagnose lung cancer only in an advanced stage in the majority of cases, which should force us to improve the diagnostics in high-risk populations, like smokers and COPD patients.
Acknowledgements The authors would like to thank Triin Umbleja for her kind assistance with statistics in this study.
Disclosure No authors report any conflict of interest.
References 1 Jemal A, Siegel R, Ward E, Murray T, Xu J, Thun MJ. Cancer statistics, 2007. CA Cancer J Clin 2007; 57: 43–66. 2 Mäkitaro R, Pääkko P, Huhti E, Bloigu R, Kinnula VL. Prospective population-based study on the survival of patients with lung cancer. Eur Respir J 2002; 19: 1087–92. 3 Mannino DM, Aguayo SM, Petty TL, Redd SC. Low lung function and incident lung cancer in United States. Data from the first National Health and Nutrition Examination Survey follow-up. Arch Intern Med 2003; 163: 1475–80. 4 Skillrud DM, Offord KP, Miller RD. Higher risk of lung cancer in chronic obstructive pulmonary disease. A prospective, matched, controlled study. Ann Intern Med 1986; 105: 503–7. 5 Tockman MS, Anthonisen NR, Wright EC, Donithan MG. Airways obstruction and the risk for lung cancer. Ann Intern Med 1987; 106: 512–8. 6 Kuller LH, Ockene J, Meilahn E, Svendsen KH. Relation of forced expiratory volume in one second (FEV1) to lung cancer mortality in the Multiple Risk Factor Intervention Trial (MRFIT). Am J Epidemiol 1990; 132: 265–74. 7 Nomura A, Stemmermann GN, Chyou PH, Marcus EB, Buist AS. Prospective study of pulmonary function and lung cancer. Am Rev Respir Dis 1991; 144: 307–11. 8 Lange P, Nyboe J, Appleyard M, Jensen G, Schnohr P. Ventilatory function and chronic mucus hypersecretion as predictors of death from lung cancer. Am Rev Respir Dis 1990; 141: 613–7. 9 Van den Eeden SK, Friedman GD. Forced expiratory volume (1 second) and lung cancer incidence and mortality. Epidemiology 1992; 3: 253–7.
Thoracic Cancer 2 (2011) 179–182 © Tianjin Lung Cancer Institute and Blackwell Publishing Asia Pty. Ltd
181
Detection of lung cancer in COPD patients
T. Laisaar et al.
10 Vestbo J, Knudsen KM, Rasmussen FV. Are respiratory symptoms and chronic airflow limitation really associated with an increased risk of respiratory cancer? Int J Epidemiol 1991; 20: 375–8. 11 Kishi K, Gurney JW, Schroeder DR, Scanlon PD, Swensen SJ, Jett JR. The correlation of emphysema or airway obstruction with the risk of lung cancer: a matched case-controlled study. Eur Respir J 2002; 19: 1093–8. 12 Wilson DO, Weissfeld JL, Balkan A et al. Association of radiographic emphysema and airflow obstruction with lung cancer. Am J Respir Crit Care Med 2008; 178: 738–44. 13 Wasswa-Kintu S, Gan WQ, Man SFP, Pare PD, Sin DD. Relationship between reduced forced expiratory volume in one second and the risk of lung cancer: a systematic review and meta-analysis. Thorax 2005; 60: 570–5. 14 Islam SS, Schottenfeld D. Declining FEV1 and chronic productive cough in cigarette smokers: a 25-year prospective study of lung cancer incidence in Tecumseh, Michigan. Cancer Epidemiol Biomarkers Prev 1994; 3: 289–98. 15 Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease: NHLBI/WHO workshop. National Heart, Lung, and Blood Institute, Claude Lenfant; World Health Organization, Nikolai Khaltaev. 1998. 16 Hole DJ, Watt GCM, Davey-Smith G, Hart CL, Gillis CR, Hawthorne VM. Impaired lung function and mortality risk in men and women: findings from Renfrew and Paisley prospective study. BMJ 1996; 313: 711–5.
182
17 Wakai K, Inoue M, Mizoue T et al. for the Research Group for the Development and Evaluation of Cancer Prevention Strategies in Japan. Tobacco smoking and lung cancer risk: an evaluation based on a systematic review of epidemiological evidence among the Japanese population. Jpn J Clin Oncol 2006; 36: 309–24. 18 Alberg AJ, Samet JM. Epidemiology of lung cancer. Chest 2003; 123: 21–49. 19 Papi A, Casoni G, Caramori G et al. COPD increases the risk of squamous histological subtype in smokers who develop non-small cell lung carcinoma. Thorax 2004; 59: 679–81. 20 Kasmel A, Lipand A, Markina A. Health Behaviour Among Adult Population. Publication of the Estonian Centre for Health Education and Promotion, Tallinn 2002. 21 de Torres JP, Bastarrika G, Wisnivesky JP et al. Assessing the relationship between lung cancer risk and emphysema detected on low-dose CT of the chest. Chest 2007; 132: 1932–8. 22 Hamilton W, Peters TJ, Round A, Sharp D. What are the clinical features of lung cancer before the diagnosis in made? A population based case-control study. Thorax 2005; 60: 1059–65. 23 Black C, de Verteuil R, Walker S Ayres J, Boland A, Bagust A, Waugh N. Population screening for lung cancer using computed tomography, is there evidence of clinical effectiveness? A systematic review of the literature. Thorax 2007; 62: 131–8.
Thoracic Cancer 2 (2011) 179–182 © Tianjin Lung Cancer Institute and Blackwell Publishing Asia Pty. Ltd
ORIGINAL ARTICLE
Detection rate of lung cancer among chronic obstructive pulmonary disease patients regularly followed up by pulmonary physicians tca_56
1
179..182
2
Tanel Laisaar , Hille Lill , Anneli Kullamaa2 & Rain Jõgi2 1 Department of Thoracic Surgery, Tartu University Hospital, Tartu, Estonia 2 Department of Pneumology, Tartu University Hospital, Tartu, Estonia
Keywords Chronic obstructive pulmonary disease; incidence; lung cancer; smoking. Correspondence Tanel Laisaar, Department of Thoracic Surgery, Tartu University Hospital, Puusepa 8, 51014 Tartu, Estonia. Tel: +372 7 318 937 Fax: +372 7 318 937 E-mail: [email protected] Received: 5 May 2011; accepted: 26 May 2011. doi: 10.1111/j.1759-7714.2011.00056.x
Abstract Background: Chronic obstructive pulmonary disease (COPD) has been found to be an independent risk factor for lung cancer. The aim of this study was to evaluate whether regular follow up of COPD patients increases the diagnosis of lung cancer at an early stage. Methods: Case reports of 105 male moderate to severe COPD patients who participated in a clinical study were analyzed retrospectively. Throughout the 3-year study period patients regularly visited a pulmonary physician. Investigations to detect lung cancer were ordered only with the presence of symptoms. The lung cancer incidence in the study group was compared to that of general male population matched by age. Results: At the beginning of the study the mean age was 67 (range 55–81) years, mean smoking history 36.2 (range 11–102) years and mean forced expiratory volume in 1 s (FEV1) 43.3% (range 22.7–59.7). During the study six lung cancers and five other cancers were diagnosed per 287 person-years of observation. Only one lung cancer was operable, others were locally advanced or had distant metastases. Conclusions: Despite the patients being followed up regularly by a pulmonary physician, most cancers were diagnosed at an advanced stage. The relative risk of getting lung cancer was 6.0 times higher (95% CI 2.7–13.3) among COPD patients than among the general population. The current study confirms that COPD patients have an increased risk of lung cancer. Moreover simple regular follow up of patients without special lung cancer screening investigations do not help to detect the cancer in its early stage. This study stresses the need to establish a more detailed follow-up program for COPD patients to detect early lung cancer in this high risk population.
Introduction Lung cancer is the leading cause of cancer death among men and in several countries also among women.1 A major problem in lung cancer management is late detection which reduces the possibilities of curative treatment and often eliminates surgery as the most effective treatment modality. Only 16–20% of lung cancers are diagnosed early enough to be surgically removed.2 Lung cancer has several risk factors; the most important one is smoking, which is also a known risk factor for chronic obstructive pulmonary disease (COPD). In addition COPD
has been found to be an independent risk factor for lung cancer. It has been demonstrated in several studies,3–12 and recently one meta-analysis showed that, independent of cigarette smoking history, reduced forced expiratory volume in 1 s (FEV1) increases the risk of lung cancer in the general population.13 Most COPD patients frequently visit their physician due to exacerbation or complications of the disease. Whether such follow up of patients increases the diagnosis of early stage lung cancer is not known. The aim of the current study was to evaluate the detection rate of lung cancer by stage at the time of diagnosis among COPD patients who regularly visit a pulmonary physician.
Thoracic Cancer 2 (2011) 179–182 © Tianjin Lung Cancer Institute and Blackwell Publishing Asia Pty. Ltd
179
Detection of lung cancer in COPD patients
T. Laisaar et al.
Table 1 Distribution of cancers diagnosed during the study period in chronic obstructive pulmonary disease patients
Case reports of 105 male moderate to severe COPD patients over 54 years of age who participated in a clinical study during the years 2000 to 2004 were analyzed retrospectively. At the beginning of the study chest radiograph was performed on all patients to exclude lung cancer. Throughout the 3-year study period, patients visited a pulmonary physician every 3 months. Patient history was obtained and lung auscultation, blood pressure measurement, and spirometry were performed at every visit; electrocardiogram was performed and a St. George respiratory questionnaire was filled out every second visit. Investigations to detect lung cancer were ordered only in the case of symptoms. No chest radiograph or computed tomography (CT) scan was done as part of the clinical study; however physicians were free to order these or other investigations in the case of suspicion of any concomitant disease, including lung cancer, arising. Lung cancer incidence in the study group was compared to that in the general male population matched by age. Data of cancer incidence in the general population was obtained from the National Cancer Registry. Summary statistics were used to describe the study population. Mean and range (min and max) were used for continuous variables; relative risk with a 95% confidence interval was used to compare the incidence of lung cancer in the study group to the respective incidence in the general male population of the same age. The current study was accepted by the institutional ethics committee and was performed in accordance with the ethical standards according to Declaration of Helsinki.
Results All patients were male. At the beginning of the study the mean age of the study subjects was 67 years (range 55–81 years). Sixty-eight patients were smokers and 37 were ex-smokers. Mean smoking history was 36.2 (range 11–102) pack years and the mean FEV1 was 43.3% (range 22.7–59.7%). During the study period of 3 years six primary lung cancers and five other cancers were diagnosed per 287 person-years of observation (Table 1). Only one lung cancer was operable (pT2N0M0 – stage Ib), others were locally advanced (one case) or with distant metastases (four cases) at the time of diagnosis. The morphological distribution of lung cancers is shown in Table 1. Lung cancer incidence was six cases per 287 person-years (2.1%) in the study group and 347 per 100 000 person years (0.35%) in the reference group (Estonian male population of the same age). The relative risk of getting lung cancer was 6.0 times higher (95% CI 2.7–13.3; P < 0.0001) among COPD patients compared to the general population (Fig 1). 180
Lung cancer Squamous cell carcinoma Small cell carcinoma Unknown Prostate cancer Laryngeal cancer Stomach cancer Colon cancer Total
6 4 1 1 2 1 1 1 11
Discussion Both COPD and lung cancer are challenging problems for a pulmonary physician, especially when combined in one patient. Several previous studies have documented that reduced FEV1 is associated with an increased risk of lung cancer.3–14 In most studies, however, only respiratory function was measured and COPD was not constantly diagnosed.5–10 We included only patients with a diagnosis of moderate or severe COPD, according to the diagnostic criteria of the Global Initiative for Chronic Obstructive Lung Disease (GOLD; based on the April 1998 Meeting Guidelines).15 Similar to previous studies, our data indicated that patients with COPD were at higher risk of developing lung cancer compared to the general population. According to a study by Mannino et al. moderate to severe COPD also increases the risk of lung cancer when compared to mild obstructive lung disease.3 It has also been documented that the percentage of predicted FEV1 is inversely related to lung cancer risk.7,14 Apart from lung cancer, decline in FEV1 is a major indicator of mortality risk for a wide range of diseases, including ischemic heart disease, stroke and other respiratory diseases.16
2.50 Lung cancer risk (%)
Materials
2.00 1.50 1.00 0.50 0.00
Estonian population
COPD patients
Figure 1 Lung cancer risk in study group (2.1%) compared to Estonian male population matched by age (0.35%). COPD, chronic obstructive pulmonary disease.
Thoracic Cancer 2 (2011) 179–182 © Tianjin Lung Cancer Institute and Blackwell Publishing Asia Pty. Ltd
T. Laisaar et al.
Various suggestions have been made to explain the relationship between COPD and lung cancer. Probably one of the most important contributors is the common risk factor, smoking. In our study group we diagnosed squamous cell carcinoma in four patients, which is related to smoking more than other morphological types of lung cancer.17 No adenocarcinoma was found among our patients, although it is an equally common or even a more frequent type of lung cancer according to recent epidemiological lung cancer studies.18 Despite the limited number of patients in our study, we seemed to demonstrate the trend of an especially high incidence of smoking-related squamous cell carcinoma in COPD patients. A similar finding of COPD increasing the risk of squamous cell carcinoma in patients with surgically resectable NSCLC has been recently published by Papi et al.19 One limitation of our study is the difference in smoking prevalence in the study group and the reference group. However, the percentage of smokers among Estonian men was as high as 44.1% in the year 2000, on top of ex-smokers whose numbers are not included.20 Taking into account previous similar studies,3,6–8,10–12 we can assume that the higher incidence of lung cancer in our study group is an independent finding and not only related to the higher prevalence of smoking. In our study COPD was diagnosed according to the GOLD criteria; we did not evaluate the severity of emphysema. Some recent data suggest that emphysema, evaluated by CT scan, like airflow obstruction, might be an independent risk factor for lung cancer.12,21 All study subjects were regularly followed up by a pulmonary physician, although no routine chest radiograph and CT scan was performed during the study period. Investigations were ordered only when patients had specific symptoms of lung cancer or other concomitant disease. Unfortunately early stage lung cancer has almost no specific symptoms, which explains the fact that only one out of six lung cancers was diagnosed at an early stage and could be treated surgically. Hamilton et al. demonstrated that the most common lung cancer symptom is cough; other specific symptoms are loss of appetite, loss of weight, dyspnea, chest pain and fatigue.22 The most specific lung cancer symptom in their study was hemoptysis, however this rarely occurs.22 All these symptoms can also be present in a patient with COPD, even hemoptysis at the time of exacerbation. Very similar symptomatology makes the diagnostics of lung cancer in a COPD patient especially difficult. Up to 20% of lung cancers are generally diagnosed in an operable stage,2 a similar percentage to our small study. These data demonstrate that regular clinical follow up, even by a pulmonary specialist, is not enough to improve lung cancer diagnostics. Routine screening for lung cancer, especially in high risk populations, could be the solution for diagnosing
Detection of lung cancer in COPD patients
more early stage lung cancers and potentially improving overall survival. A recent systematic literature review of lung cancer screening studies by Black et al. demonstrated that CT screening allows diagnosis of a high proportion of stage I lung cancer, even 100% in some studies.23 In summary our study demonstrated 6.0 times higher relative risk of lung cancer among COPD patients compared to that of general population. More importantly, despite regular follow up of patients, we were able to diagnose lung cancer only in an advanced stage in the majority of cases, which should force us to improve the diagnostics in high-risk populations, like smokers and COPD patients.
Acknowledgements The authors would like to thank Triin Umbleja for her kind assistance with statistics in this study.
Disclosure No authors report any conflict of interest.
References 1 Jemal A, Siegel R, Ward E, Murray T, Xu J, Thun MJ. Cancer statistics, 2007. CA Cancer J Clin 2007; 57: 43–66. 2 Mäkitaro R, Pääkko P, Huhti E, Bloigu R, Kinnula VL. Prospective population-based study on the survival of patients with lung cancer. Eur Respir J 2002; 19: 1087–92. 3 Mannino DM, Aguayo SM, Petty TL, Redd SC. Low lung function and incident lung cancer in United States. Data from the first National Health and Nutrition Examination Survey follow-up. Arch Intern Med 2003; 163: 1475–80. 4 Skillrud DM, Offord KP, Miller RD. Higher risk of lung cancer in chronic obstructive pulmonary disease. A prospective, matched, controlled study. Ann Intern Med 1986; 105: 503–7. 5 Tockman MS, Anthonisen NR, Wright EC, Donithan MG. Airways obstruction and the risk for lung cancer. Ann Intern Med 1987; 106: 512–8. 6 Kuller LH, Ockene J, Meilahn E, Svendsen KH. Relation of forced expiratory volume in one second (FEV1) to lung cancer mortality in the Multiple Risk Factor Intervention Trial (MRFIT). Am J Epidemiol 1990; 132: 265–74. 7 Nomura A, Stemmermann GN, Chyou PH, Marcus EB, Buist AS. Prospective study of pulmonary function and lung cancer. Am Rev Respir Dis 1991; 144: 307–11. 8 Lange P, Nyboe J, Appleyard M, Jensen G, Schnohr P. Ventilatory function and chronic mucus hypersecretion as predictors of death from lung cancer. Am Rev Respir Dis 1990; 141: 613–7. 9 Van den Eeden SK, Friedman GD. Forced expiratory volume (1 second) and lung cancer incidence and mortality. Epidemiology 1992; 3: 253–7.
Thoracic Cancer 2 (2011) 179–182 © Tianjin Lung Cancer Institute and Blackwell Publishing Asia Pty. Ltd
181
Detection of lung cancer in COPD patients
T. Laisaar et al.
10 Vestbo J, Knudsen KM, Rasmussen FV. Are respiratory symptoms and chronic airflow limitation really associated with an increased risk of respiratory cancer? Int J Epidemiol 1991; 20: 375–8. 11 Kishi K, Gurney JW, Schroeder DR, Scanlon PD, Swensen SJ, Jett JR. The correlation of emphysema or airway obstruction with the risk of lung cancer: a matched case-controlled study. Eur Respir J 2002; 19: 1093–8. 12 Wilson DO, Weissfeld JL, Balkan A et al. Association of radiographic emphysema and airflow obstruction with lung cancer. Am J Respir Crit Care Med 2008; 178: 738–44. 13 Wasswa-Kintu S, Gan WQ, Man SFP, Pare PD, Sin DD. Relationship between reduced forced expiratory volume in one second and the risk of lung cancer: a systematic review and meta-analysis. Thorax 2005; 60: 570–5. 14 Islam SS, Schottenfeld D. Declining FEV1 and chronic productive cough in cigarette smokers: a 25-year prospective study of lung cancer incidence in Tecumseh, Michigan. Cancer Epidemiol Biomarkers Prev 1994; 3: 289–98. 15 Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease: NHLBI/WHO workshop. National Heart, Lung, and Blood Institute, Claude Lenfant; World Health Organization, Nikolai Khaltaev. 1998. 16 Hole DJ, Watt GCM, Davey-Smith G, Hart CL, Gillis CR, Hawthorne VM. Impaired lung function and mortality risk in men and women: findings from Renfrew and Paisley prospective study. BMJ 1996; 313: 711–5.
182
17 Wakai K, Inoue M, Mizoue T et al. for the Research Group for the Development and Evaluation of Cancer Prevention Strategies in Japan. Tobacco smoking and lung cancer risk: an evaluation based on a systematic review of epidemiological evidence among the Japanese population. Jpn J Clin Oncol 2006; 36: 309–24. 18 Alberg AJ, Samet JM. Epidemiology of lung cancer. Chest 2003; 123: 21–49. 19 Papi A, Casoni G, Caramori G et al. COPD increases the risk of squamous histological subtype in smokers who develop non-small cell lung carcinoma. Thorax 2004; 59: 679–81. 20 Kasmel A, Lipand A, Markina A. Health Behaviour Among Adult Population. Publication of the Estonian Centre for Health Education and Promotion, Tallinn 2002. 21 de Torres JP, Bastarrika G, Wisnivesky JP et al. Assessing the relationship between lung cancer risk and emphysema detected on low-dose CT of the chest. Chest 2007; 132: 1932–8. 22 Hamilton W, Peters TJ, Round A, Sharp D. What are the clinical features of lung cancer before the diagnosis in made? A population based case-control study. Thorax 2005; 60: 1059–65. 23 Black C, de Verteuil R, Walker S Ayres J, Boland A, Bagust A, Waugh N. Population screening for lung cancer using computed tomography, is there evidence of clinical effectiveness? A systematic review of the literature. Thorax 2007; 62: 131–8.
Thoracic Cancer 2 (2011) 179–182 © Tianjin Lung Cancer Institute and Blackwell Publishing Asia Pty. Ltd
