Common Lung Cancer Symptoms
Some patients present without lung cancer symptoms when a chest X-ray is performed for other reasons (e.g. pre-operatively or for a medical) but the majority of lung cancer patients are symptomatic at presentation.
Common presenting features of lung cancer symptoms are recurrent infections in a smoker, exacerbation of a cough or increasing shortness of breath. Fatigue or weight loss can often be present. Haemoptysis (coughing up blood) is common.
Mesotheliomas tend to present more insidiously, with non-specific symptoms of slowly progressive disease. The commonest symptoms are breathlessness, often due to a pleural effusion (fluid surrounding the lung) and chest pain due to the presence of the tumour on the pleural surface or invading the chest wall.
Causes of Lung Cancer
It has long been established that the major risk factor in lung cancer development is smoking. Although the risk is greater with increasing numbers of cigarettes smoked, the duration of smoking is a stronger risk factor than daily intake.
Ninety percent of patients who develop lung cancer are, or have been smokers. Other carcinogens may predispose to lung cancer risk, such as asbestos, radiation, and also arsenic, mustard and radon gas, chromium, and nickel.
Exposure to asbestos, particularly crocidolite, (blue asbestos) is linked with the development of mesothelioma. Some lung cancers are not related to smoking, such as adenocarcinoma and its subgroup alveolar cell carcinoma.
Although there are strong environmental factors leading to lung cancer development, individuals differ in their sensitivities, and there is increasing evidence that genetic factors may play a role in lung cancer development.