Did you know that lung cancer is one of the most commonly diagnosed cancers? An estimated, 1.61 million new cases of lung cancer are reported worldwide every year accounting for 1.38 million deaths. In India, around 63,000 new lung cancer cases are reported. It is observed mainly in an old age and diagnosed commonly in people aged 70-74 years. It is uncommon in people younger than 40 years of age.
Lung cancer is the uncontrolled growth of abnormal cells in one or both lungs. Lung cancer can be primary (develops in the lungs) or secondary (develops in other parts of body and spreads to lungs) depending on its origin. Primary lung cancer is further classified as small-cell lung cancer and non-small-cell lung cancer (NSCLC). Small cell lung cancer is almost always associated with cigarette smoking. NSCLC is more common accounting for more than 80% of cases. This type of cancer usually grows and spreads to other parts of the body more slowly than small cell lung cancer does. There are three different types of NSCLC: squamous cell carcinoma, adenocarcinoma and large-cell lung cancer, which is less common and usually spreads faster than non-small-cell lung cancer. It is important to know the type of lung cancer you have because it helps determine what treatment options are available.
Lung cancer develops silently, generally there are no typical symptoms observed in an early stages. However a patient may eventually develop persistent cough, coughing blood, persistent breathlessness, tiredness, sudden weight loss, pain while breathing or coughing, and hoarseness. Diagnosis of lung cancer is preliminarily done by chest X-ray, however, it is not the robust method as it may not be able to distinguish between lung cancer and tuberculosis. CT, PET-CT scan, bronchoscopy and biopsy are some of the confirmatory diagnostic tests for lung cancer. Treatment includes surgical removal of cancerous tissue (if confined to one region), radiotherapy and chemotherapy. The people in age group >70 years have many co-morbid conditions like heart disease, diabetes and are not good risk for surgical treatment. Stereotactic body radiotherapy (SBRT) by way of Cyberknife or LINAC is a good treatment alternative in such cases. A low dose CT chest is recommended for a person who has history of >60 pack years of smoking as this can pick-up early stage cancers.
Lung cancer is often considered as solely a smoker’s disease. Since tobacco use is one of the major risk factor for development of disease. However, a considerable number of patients without history of smoking develop lung cancer. This is expected to increase due to unsuccessful implementation of smoking prevention, cessation programmes and development of smoking alternatives like nicotine chewing gums. Trend of lung cancer among the never-smoker population in Asia is gender bias. Women are diagnosed in a greater proportion then men. Various factors including passive smoking, human papilloma virus infection, idiopathic pulmonary fibrosis, genetic factors and other environmental exposures like asbestos, arsenic, and radon are believed to be responsible for the development of lung cancer in non-smokers. Studies suggest that lung cancer in non-smokers is diagnosed at a more advanced stage. It may be due to a fact that when a non-smoker presents with a lung cancer, cancer is not at the top of the list of diagnoses by physician. Some studies also suggest 20% patients of lung cancer wrongly receive anti-tuberculosis treatment. In 70% of all patients with less than 40 years of age, diagnosis is delayed due to erroneous diagnosis of tuberculosis in 55% patients. Thus, there is a need for awareness of physicians that lung cancer is not always related to smoking and not every chest abnormality can be viewed with a suspicion of tuberculosis.
American Society of Clinical Oncologists guidelines have suggested annual screening for smokers and former smokers at high risk for developing lung cancer.
At the end, the importance of awareness about cancer in order to manage it successfully cannot be stressed enough hence November is observed as Lung Cancer Awareness month by American Cancer Society.