Main Article Content
RATIONALE: Clinical physicians commonly find pulmonary nodules difficult tointerpret when these are found in radiographic images. This finding requires specialskills to use the correct diagnostic method to properly distinguish between malignantand benign nodules. Prompt identification of a nodule or tumor is necessary so treatmentstrategies essential for prognosis can be implemented. Over the past few years, the MayoClinic lung cancer probability formula has been validated by several researchers todetermine if this equation is an effective tool in helping to identify lung cancer. Thepurpose of this study is to verify whether this formula is applicable to patients living inAsian countries where tuberculosis (TB) is prevalent.
MATERIALS AND METHODS: Between 2012 and 2014, we retrospectivelycollected and reviewed the medical records of 54 patients in Bangkok Hospital MedicalCenter who tested positive with lung nodules or mass, measuring 4.5- 88 mm in diameteras reported from their chest computed tomography (CT) scan. Data gathered included:patient age, gender (male or female), race (Asian or Non-Asian), smoking history(smoker, previous smoker or never having smoked), extrathoracic cancer for more than5 years prior to the consultation, lung nodule or tumor location (upper, middle, lower),spiculated morphology and final definite tissue diagnosis as collected through Fiberopticbronchoscopy (FOB), Endobronchial Ultrasound (EBUS), Electromagnetic NavigationBronchoscopy (ENB) and Video Assisted Thoracoscopic Surgery (VATS). We evaluatedthe accuracy of the Mayo Clinic formula for estimating the probability of lung cancerby computing then comparing the lung cancer probability result versus the final diagnosis.
RESULTS: For the 54 patients with a confirmed final diagnosis, lung cancer was foundin 16 patients, tuberculosis with non-tuberculous mycobacteria (NTM) infection in 24patients, 11 cases were diagnosed with lung cancer with tuberculosis and 3 casesappeared to be a benign tumor. In the first category, in patients diagnosed with lungcancer, the result from the Mayo Clinic formula was 74.7%. In Category 2 (TB andNTM infection), lung cancer probability was 27.8%, in category 3 (lung cancer and TB)the probability was 76% and in category 4 (benign) the probability was 17.9%.
CONCLUSION: The Mayo Clinic formula is an effective and useful tool in predictinglung cancer probability even among Asian communities where there is high incidenceof tuberculosis. However, we must also consider that this formula though beneficial,should not be the sole basis of diagnosis when screening for lung cancer.
This is an open access article distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
2. National Lung Screening Trial Research Team, Aberle DR, Adams AM et al. Reduced lung-cancer mortality with low-dose computed tomographic screening. N Engl J Med 2011; 365:395-409.
3. Heuvers ME, Wisnivesky J, Stricker BH, et al. Generalizability of results from the National Lung Screening Trial. Eur J Epidemiol 2012; 27:669-72.
4. Optican RJ, Chiles C. Implementing lung cancer screening in the real world: opportunity, challenges and solutions. Trans Lung Cancer Res 2015;4(4):353-64.
5. Siegelman SS, Khouri NF, Leo FP, et al. Solitary pulmonary nodules: CT assessment. Radiology 1986;160:307-12.
6. Khouri NF, Meziane MA, Zerhouni EA, et al. The solitary pulmonary nodule: assessment, diagnosis, and management. Chest 1987;91:128-33.
7. Higgins GA, Shields TW, Keehn RJ. The solitary pulmonary nodule: ten-year follow-up of Veterans Administration- Armed Forces Cooperative Study. Arch Surg 1975;110:570-5.
8. Ray JF, Lawton BR, Magnin GE, et al. The coin lesion story: update 1976: twenty years’ experience with early thoracotomy for 179 suspended malignant coin lesions. Chest 1976; 70:332-6.
9. Ost D, Fein AM, Feinsilver SH. The Solitary Pulmonary Nodule. N Engl J Med 2003; 348:2535-42.
10. Bai C, Choi CM, Chu CM, et al. Evaluation of pulmonary nodules: clinical practice consensus guidelines for Asia. Chest 2016;150(4):877-93.
11. Zhang X, Yan HH, Lin JT, et al. Comparison of three mathematical prediction models in patients with a solitary pulmonary nodule. Chin J Cancer Res 2014;26(6):647-52.
12. World Health Organization. Global tuberculosis report 2015. Geneva Switzerland. WHO/HTM/TB/2015.22. ISBN 978 92 4 156505 9. (Accessed May 3, 2016 at http://apps.who.int/iris/bitstream/10665/191102/1/ 9789241565059_eng.pdf.).
13. Bhatt MLB, Kant S, Bhaskar R. Pulmonary tuberculosis as differential diagnosis of lung cancer. South Asian J Cancer 2012; 1(1):36-42.
14. Silva DR, Valentini DF, Muller AM, et al., Pulmonary tuberculosis and lung cancer: simultaneous and sequential occurrence. J Bras Pneumol 2013;39(4):484-9.
15. Dacosta NA, Kinare SG. Association of lung carcinoma and tuberculosis. J Postgrad Med 1991;37(4):185-9.
16. Liang HY, Li XL, Yu XS, et al., Facts and fiction of the relationship between preexisting tuberculosis and lung cancer risk: a systemic review. Int J Cancer 2009;125(12):2936-44.
17. Wu CY, Hu HY, Pu CY, et al., Pulmonary tuberculosis increases the risk of lung cancer: a population-based cohort study. Cancer 2011; 117(3):618-24.
18. Saenghirunvattana S, Kurimoto N, Suwanakijboriharn C, et al. Etiology of Size Based Pulmonary Nodules in Asia. Poster presentation American Thoracic Society (ATS) 2015.
19. Schultz EM, Sanders GD, Trotter PR, et al. Validation of two models to estimate the probability of malignancy in patients with solitary pulmonary nodules. Thorax 2008;63:335-41.
20. 20. Tan CH, Kontoyiannis DP, Viswanathan C, et al. Tuberculosis: A Benign Imposter. American Roentgen Ray Society (AJR) 2010;194:555-61.
21. Cicenas S, Vencevicius V. Lung cancer in patients with tuberculosis. World J Surg Oncol 2007;5:22.
22. Rolston KVI, Rodriguez S, Dholakia N, et al., Pulmonary infections mimicking cancer: a retrospective, three-year review. Support Care Cancer 1997;5:90-3.
23. Rihawi A, Huang G, Al-Haji A, et al. A case of tuberculosis and adenocarcinoma coexisting in the same lung lobe. Int J Mycobacteriol 2016;5(1):80-2.
24. Gould MK, Ananth L, Barnett PG. A clinical Model to Estimate the Pretest Probability of Lung Cancer in Patients with Solitary Pulmonary Nodules. Chest 2007;131(2):383-8