All you need to know about lung cancer
Lung cancer is the leading cancer worldwide in terms of incidence and mortality. Only 15% of patients who develop lung cancer survive for 5 years. There is no definitive population-based cancer registry in Bangladesh, so it is difficult to find out the incidence and mortality of any kind of cancer.
Early detection is a must, to ensure successful treatment of lung cancer. Hence, the general public needs to be educated so that they can recognise the early warning signs by themselves. This will enable them to seek timely medical intervention.
Smoking plays a great role in lung cancer. It is assumed that cigarette smoking is the most important single factor and directly responsible for at least 80% of lung cancers. The risk of lung cancer increases with the number of cigarettes smoked, years of smoking duration, earlier age at onset of smoking, degree of inhalation, nicotine content and use of unfiltered cigarettes and it decreases in proportion to the number of years after smoking cessation.
The smoke inhaled by non-smokers has a similar chemical composition to that inhaled by smokers but has higher N-nitrosamine levels and smaller size particle which remain suspended in the air and can more easily penetrate the bronchial tree. About one-third of cases of lung cancer are in non-smokers who live with smokers.
After the combustion of tobacco, it yields smoke in two phases. One is the particulate phase and the other is the gaseous phase. More than 3000 chemicals have been identified in tobacco smoke.
Understanding the natural history of lung cancer is important for prevention, early detection, rationally planned initial curative or palliative therapy, anticipation of possible complications and the institution of therapy at the time of relapse. The natural history of a susceptible host to carcinogenic agents, which leads to progressive changes from metaplasia, to atypia and dysplasia, and ultimately to carcinoma in situ and invasive cancer.
Signs and symptoms of lung cancer includecough, Chest pain, fever, respiratory distress, Blood mixed with cough, voice change, loss of appetite etc.
Diagnosis is based on careful history from the patient and physical examination, pulmonary function tests, sputum for cytology, imaging studies, radionuclide scanning, bronchoscopy, percutaneous fine needle aspiration and cytology, percutaneous fine needle aspiration and biopsy and thoracoscopy etc.
Treatment of lung cancer depends on the stage of the disease and histopathology type. The treatment modalities are surgery, radiotherapy, chemotherapy, immunotherapy and targeted therapy. Surgery is possible when the disease is at an early stage. The principle of radiotherapy is to give the radiation dose to the cancer area, not to surrounding normal tissues. It is possible due to the modern-day radiotherapy technique. Sometimes radiotherapy is given for pain and palliative management also.
More than 80% of lung cancer cases can be avoided if we stop smoking and take care of other lung diseases like infectious tuberculosis. It is important to quit smoking as soon as possible to avoid the risk of developing lung cancer. Mass awareness campaigns are of much importance to aware people about the dangerous effects of smoking.
The writer is the Head of the Department of Oncology, Delta Medical College and Hospital, Bangladesh. E-mail: manzur2001bd@yahoo.com