Lung cancer can take many years to develop and is diagnosed and treated in a similar way to that of mesothelioma albeit the two diseases differ characteristically.
In the first instance your GP will examine you thoroughly and listen to your lungs with a stethoscope in order to establish if there is any laboured breathing, wheezing or fluid in the lungs. Other aspects of your general health, family history and in particular any symptoms or other concerns you might have will be discussed and it is important you outline details of your earlier exposure to asbestos at your initial physical examination.
In 2015 the National Institute for Health and Care Excellence (NICE) published guidelines to help GP’s recognise signs and symptoms of lung cancer to ensure those affected receive the appropriate tests without undue delay.
A number of investigations are used to provide a detailed lung cancer diagnosis from which a treatment plan will emerge and might include;
A blood test is often required to eliminate other possible causes of the symptoms.
A lung function test might include spirometry which involves blowing through a mouthpiece into a spirometer to measure how well you can inhale and exhale. You will be asked to use maximum effort in this test which could temporarily leave some people feeling tired and lightheaded.
Flow patterns are either normal or abnormal, and if abnormal they show either as an obstructive pattern or a restrictive pattern. An obstructive pattern would indicate some narrowing of the airways in line with average expectations based upon age, height and weight which could include diseases such as Chronic Obstructive Pulmonary Disease (COPD) and asthma. A restrictive pattern characterised by reduced lung volumes would suggest some scarring or deformity in the lungs which could be due to an interstitial lung disease, trapped lung, pleural scarring, large pleural effusion, chronic empyema and asbestosis.
Spirometry when used in conjunction with other tests can help eliminate certain lung conditions and allow for a clearer diagnosis and treatment of certain lung conditions such as folded lung, COPD, chronic bronchitis, asthma, pulmonary fibrosis (including idiopathic pulmonary fibrosis) and cystic fibrosis. It can also help to understand the severity of a lung disease, measure the extent of any deterioration and help to assess any benefit derived from any medication.
In lung cancer cases spirometry can be used to evaluate and assess treatments for respiratory symptoms and to determine suitability to certain lung cancer surgical procedures.
An x-ray in many cases will highlight abnormalities in the lungs but is not considered definitive due to difficulties in distinguishing between cancer and other conditions.
CT Scan (computerised tomography)
A CT Scan normally follows a chest x-ray and is a painless process involving a series of x-rays which produce a 3D image of the lungs. A CT Scan can help differentiate malignant from benign disease and will provide reliable information regarding the location and thickness of any tumours in the lungs.
The result of the CT Scan is not always conclusive and further investigation is often necessary.
PET Scan (positron emission tomography)
A PET Scan is a specialised imaging test which can help to identify cancer at an early stage and the presence of active cancer cells not detected by other tests which can help in the diagnosis and treatment of cancer.
Bronchoscopy and biopsy
If anything suspicious is detected a tissue sample will be required to enable microscopic examination (normally by a Pathologist) of the cell types present and if cancerous. A bronchoscopy is one such procedure which involves examination under general anaesthetic of the airways of your lungs via a soft thin tube which is passed through your nose or mouth.
Other forms of biopsy include,
CT or ultrasound guided biopsy – Under local anaesthetic a special type of needle is inserted into the affected area, guided by ultrasound or CT scanner, to enable targeted removal of tissue samples.
Thoracoscopy (also referred to as VATS, video assisted thoracoscopy) – This is a reliable method of obtaining tissue and fluid samples for biopsy which is less invasive than surgical lung biopsy and is normally obtained under general anaesthetic. A thin tube with lighted scope and camera (thoracoscope) is inserted through a cut made in the chest wall which allows for detailed examination of the lung structures.
Mediastinoscopy – This procedure allows examination of the central area between the lungs (mediastinum) by passing a thin soft tube into the chest via a small incision in front of the trachea. Using a camera-scope known as a ‘mediastinoscope’ this allows biopsy of the lymph nodes which is where cancer normally spreads to.