Key Difference – Lung Cancer vs. Tuberculosis
Lung cancer is a cancerous growth of the lung tissue that can metastasize to other organs of the body. Tuberculosis is a chronic infective disease mainly caused by Mycobacterium tuberculosis. Both conditions affect the lungs, but they have different pathology. The key difference between lung cancer and tuberculosis is that the lung cancer is the malignancy of the lungs, but tuberculosis is a chronic infection. Through this article let us clarify this difference in detail.
What is Lung Cancer?
Lung cancer is an abnormal and uncontrolled growth of the lung tissue. Smoking is the number one risk factor for lung cancer. Common histological types of lung cancer are small cell lung cancer and non-small cell lung cancer (squamous cell lung cancer, adenocarcinoma, Broncho alveolar carcinoma, and large cell carcinoma). Lung cancer can spread locally and metastasize to distant tissues. It also causes paraneoplastic syndromes much as neurological and endocrine manifestations. Lung cancer needs proper assessment with biopsy and histological diagnosis. CT scanning is used to assess the spread of the tumor (staging). Small cell lung cancer is treated with chemotherapy. In contract, non-small cell cancer can be treated with surgery combined with chemotherapy. Radiotherapy can be used in both forms of lung cancer. Advanced lung cancer is not curable with the treatment.
What is Tuberculosis?
Tuberculosis is a chronic infective disease caused by Mycobacterium species. It mainly affects lung but can affect any other organ system of the body. TB is spread by respiratory secretions of an affected person. Main predisposing factors are immune suppression and poor sanitation and living conditions. TB bacilli can multiply within tissues resisting body immune mechanisms such as macrophages. It causes granuloma formation that are characterized by caseation necrosis. Later it can cause cavitation in the lungs. Other than cavitation, TB can cause bronchopneumonia, pleural effusions, empyema, bronchiectasis, and lung fibrosis leading to respiratory failure. Patients will get chronic cough (more than three weeks), sputum, hemoptysis, and other respiratory manifestations. Nonspecific symptoms such as evening pyrexia (fever), night sweat, loss of appetite, and weight loss are also common with this condition.
TB is diagnosed by an acid-fast stain (AFB), culture, and polymerase chain reaction (PCR), etc. Adenosine deaminase assay, gamma interferon assay, Mantoux test, and imaging are other supportive investigations in the diagnosis. Anti-tuberculous therapy is available and commonly used medicines are isoniazid, rifampicin, ethambutol, and pyrazinamide. There are other antibiotics to treat resistant TB infections. BCG vaccine is given to newborn babies to prevent a severe form of infection and disseminated infection.
What is the difference between Lung Cancer and Tuberculosis?
Definition:
Lung cancer is an abnormal and uncontrolled growth of the lung tissue.
Tuberculosis is a chronic infective disease caused by Mycobacterium species.
Pathology:
Lung cancer is the malignancy of the lungs.
TB is a chronic infection.
Communicability:
Lung cancer doesn’t spread from one person to the other.
TB can be spread from one person to the other via respiratory droplets.
Risk Factors:
Smoking, asbestos, and scarring of the lung are some risk factors for lung cancer.
Immune suppression, malnutrition, poor housing condition are some of the important risk factors for TB.
Diagnosis:
Lung cancer is diagnosed by biopsy and histology.
TB is diagnosed by sputum AFB, culture, and PCR.
Treatment:
Lung cancer is treated with chemotherapy, radiotherapy, and surgery. However, in most occasions is it not curable.
TB is treated with a long course of antituberculous therapy, and it is curable with proper compliance.
Image Courtesy:
1. “LungCACXR” by James Heilman, MD – Own work. Licensed under CC BY-SA 3.0 via Commons
2. Tuberculosis symptoms By Häggström, Mikael. “Medical gallery of Mikael Häggström 2014”. Wikiversity Journal of Medicine 1 (2). DOI:10.15347/wjm/2014.008. ISSN 20018762. [Public domain], via Wikimedia Commons
