Note: The information on cancer types on the ACRF website is not designed to provide medical or professional advice and is for information only. If you have any health problems or questions please consult your doctor.
In patients with lung cancer, abnormal cells develop in one or both lungs and grow in an uncontrolled way to form tumours.
These tumours can affect how the lungs usually work, which is to supply oxygen to the body through the bloodstream and remove carbon dioxide from the body.
Lung cancer develops when cells in the lung grow abnormally to form a tumour.
Air that is breathed in the lungs flows through tubes called bronchi, which branch into smaller airways called bronchioles. These branches end in tiny sacs, called alveoli, where oxygen and carbon dioxide is exchanged.
Although lung cancer can develop in any part of the lung, most lung cancers begin in the cells that line these air passages (the bronchi) and the airway branches (alveoli or bronchioles) in the lung.
Lung cancer cells that remain within the lungs are classed as non-invasive lung cancer. When the tumour invades normal tissues in the lung, the tumour is considered to be malignant. The cells can also invade and multiply in nearby parts of the body, such as the chest wall or diaphragm, obtaining a new blood supply to continue tumour growth.
Lung cancer cells can spread from the lungs to other parts of the body by breaking away from the lung cancer tumour, invading nearby normal lung tissue and travelling through blood vessels or lymph vessels to reach other parts of the body. This process is called metastasis.
The most common sites are the adrenal gland, bone, brain, liver or the other lung. Lung cancer that spreads from the lungs to other parts of the body is called metastatic, secondary or advanced lung cancer.
The most common type of lung cancer is called non-small cell lung cancer. Non-small cell lung cancers include, squamous cell carcinoma that starts in the cells that line the airways of the lungs, adenocarcinoma the most common type of non-small cell lung cancer starting the mucous-secreting lung cells or large cell carcinoma.
The other type of lung cancer is called small cell lung cancer, which usually starts in the bronchi, and grows and spreads to other parts of the body quickly.
Lung cancer that is made up of both these types is called mixed small cell/large cell cancer.
There are other types of lung cancer that occur less frequently in patients called lung carcinoid tumours. Most of these tumours grow slowly and rarely spread to other parts of the body.
Staging describes where the lung cancer is located, if it has spread and whether the tumour is affecting other parts of the body. Diagnostic and laboratory tests can be ordered based on the stage and type of lung cancer to help determine the treatment.
Non-small cell lung cancer is divided into six stages; occult (hidden) stage lung cancer cells found in the sputum or fluid from the lung, and stage 0 (carcinoma in-situ) when the lung cancer cells have not spread to lymph nodes. Stage 1A, and 1B, stage 2A and 2B, stage 3A and 3B are when the tumour is increasing in size and spreading to nearby lymph nodes. Stage 4 is when lung cancer has spread to the opposite lung and other parts of the body.
A sign of lung cancer is a presentation noticed by another person – for example, coughing up blood or having a persistent cough are common signs of lung cancer. A symptom is a feeling, such as fatigue or loss of appetite.
Lung cancer sometimes may not produce any signs and symptoms in the early stages or may appear in patients when the disease is already advanced.
Lung cancer begins when cells grow abnormally and form tumours in the lungs. Signs and symptoms of lung cancer vary depending on whether the lung cancer has spread to other parts of the body, the size of the tumour and how much the tumour is affecting other organs in the body.
There are other medical conditions that can have the same symptoms or signs as lung cancer and it is important to encourage patients to visit their doctor for persistent symptoms for detection and diagnosis of lung cancer.
The most common signs and symptoms of early lung cancer are:
The earlier lung cancer is detected, the more likely it is that treatment can successfully remove the cancer and prevent it from recurring.
Constantly improving treatments are helping to gradually reduce rates of lung cancer globally. Treatment for lung cancer depend on the stage at the time of diagnosis, which includes the size of the tumour and if the tumour has spread in the lung, the type of lung cancer, cancer gene mutations and the overall health of the patient.
Diagnostic tests and procedures to detect lung cancer include, physical examination, chest x-rays, imaging scans of the chest, bronchoscopy, mediastinoscopy and video-assisted thoracoscopy. Laboratory tests may be ordered if symptoms suggest the existence of lung cancer tumours. This includes assessment of tissue samples, removing fluid from lungs, sputum (mucous coughed up from the lungs) or blood in urine.
Lung cancer treatment can include, surgery to remove part or the whole lobe of the lung, the entire lung or part of the lung airway (bronchus). Radiation therapy and chemotherapy are also treatment options for patients.
An emerging body of research is indicating that knowing a tumour’s genomic profile could be more important for successful treatment than knowing its location or size. As each tumour’s genomic profile is unique, this approach is often referred to as personalised or precision medicine.
Treatment for lung cancer does depend on the stage of the cancer, the patient’s breathing capacity and general health. In most cases surgical removal of a tumour offers the best chance of a cure for patients who have early-stage lung cancer.
Non-small cell carcinoma is best treated with surgery if possible – this will depend on the size and location of the tumour. Otherwise a combination of radiotherapy and chemotherapy can be an option.
Small cell carcinoma is usually treated with chemotherapy. Some people with cancer in one lung (known as limited) will have the option of preventative radiotherapy to the chest and brain. Since small-cell carcinoma usually spreads early, surgery is not usually advised for this type of cancer.
It is important to note that not all patients who develop lung cancer are smokers.
Patients who have a non-smoking or smoking relative who has had lung cancer can inherit damaged DNA. Being aged 60 years old and over also increases the risk for being diagnosed with lung cancer.
Patients who are infected with HIV, have certain diseases of the lungs or are being treated with radiation therapy to the breast or chest may be at increased risk of lung cancer. Other known environmental risk factors for lung cancer include, exposure to asbestos fibres, nickel or soot in the workplace, living where there is air pollution and radiation exposure to radon gas.
Increased awareness of lung cancer risks, such as smoking, is helping patients reduce their risk of developing lung cancer. Quitting smoking and reducing exposure to passive tobacco smoke can significantly reduce patient risk for developing lung cancer, with the risk of lung cancer decreased after years of quitting.
Raising awareness of risks with smoking and environmental factors for lung cancer, encouraging patients to learn their family history, and referring at-risk patients for regular screening checks are all important preventative measures.
new cases are estimated to be diagnosed in 2018
is the five-year relative survival rate for lung cancer
years is the median age of diagnosis
Together we can change the statistics and outsmart cancer for good
Cancer in Australia 2017, Australian Institute of Health and Welfare
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