Non-Small Cell Lung Cancer (NSCLC)

Lung cancers are one of the most common cancers worldwide. Lung cancers are classified as either small cell lung cancer (SCLC) or non-small cell lung cancer (NSCLC).
Non-small cell lung cancers refers to a subset of cancer types that account for approximately 70% of lung cancers, including squamous cell carcinoma of the lung, large cell carcinoma of the lung, and adenocarcinoma of the lung.
Lung cancer is common. One in every 28 Australians will develop lung cancer during their lifetime. Lung cancer is also deadly: it is the most common cause of cancer death in Australia, accounting for around 23% of male and 15% of female cancer deaths. Lung cancer is more than twice as common in men as in women.
Geographically, the tumour is found worldwide, but it is especially common in countries with high tobacco consumption. As a group, non-small cell lung cancers make up about 70% of all lung cancers.
Cigarette smoking is the main predisposing factor. In recent years, it has been recognised that passive smoking (e.g. from a first degree relative in a house of smokers) can also put people at risk. Generally, the risk increases with the number of cigarettes smoked.
Exposure to asbestos increases the risk of developing this tumour. The combination of asbestos exposure plus cigarette smoking is particularly harmful. Other occupational exposures such as exposure to metals including arsenic, chromium and nickel can also increase risk.
Some studies have suggested that diet can play a role in lung cancer risk. Though it is not known how it works, diets high in fruits and vegetables seem to decrease risk.
Radiation exposure damages the DNA material within the cells and can also cause lung cancer. Radon (a radioactive gas) exposure from our normal surrounding environment, if higher than normal, can predispose to lung cancer. This evidence is mainly based upon population studies which show that people living in areas with a high radon content are prone to increased incidences of a variety of cancers.
Primary lung cancers are classified as either small cell tumours or non-small cell tumours. Non-small cell lung cancers include the subtypes squamous cell carcinoma of the lung, large cell carcinoma of the lung, and adenocarcinoma of the lung. These cancers are grouped together because they behave in a similar fashion, and, when diagnosed at an early stage, they may be cured by surgery.
As they grow, non-small cell lung cancers can spread to distant organs via the bloodstream or lymphatic vessels to the adrenal glands, liver, brain and bone.
Patients with lung cancer may notice:
Rarely, patients may present with difficulty swallowing or wheezing. Patients who have metastases (distant spread) at diagnosis may have symptoms related to this spread. For example, patients with cancer spread to the bone may experience bone pain or fractures.
Blood tests:

Imaging tests:
Chest x-ray: lung cancer may be seen on chest x-ray as a solitary pulmonary nodule or mass. As many as 80% of solitary pulmonary nodules (CT scanning: this is more accurate than chest x-ray, and may be particularly useful in identification of lymph node involvement. See the example image below.PET scanning can help to distinguish between benign and malignant solitary pulmonary nodules seen on chest x-ray. PET scanning may also be used in the assessment of nodal spread and metastatic disease.Imaging of other organs: if it is suspected that the cancer has spread to other organs, scans of the liver, brain or bone may be required.

While imaging tests are helpful in raising the suspicion of lung cancer, diagnosis requires that cancer cells are seen under a microscope. There are a number of ways of obtaining samples of suspected cancer cells:
Sputum cytology: cells from the sputum (spit) are examined for signs of malignancy (cancer)Bronchoscopy with washings, brushings and biopsy: a bronchoscopy is a camera tube placed through the throat into the airways of the lungs. Samples of the cells from the airways can be taken with washing, brushing, or biopsy.Fine needle aspiration biopsy through the skin may be used to investigate suspected lung tumours located near the edges of the lungs.
The prognosis (probable outcome) depends on the stage of the tumour. Cancer staging is a tool which allows prediction of patient outcomes, and helps decide on the best treatment options. It takes into account various features of a tumour in an individual patient, which can then be compared to other patients with similar tumour features.
Staging of non-small cell carcinoma of the lung is based on the TNM (Tumour, Node, Metastasis) system. 'Tumour' refers to tumour size, which is measured in centimetres. 'Node' refers to the presence of cancerous cells in regional lymph nodes. 'Metastasis' refers to the spread of cancer beyond regional lymph nodes to other organs of the body.
Tumour size (T): Tx: Primary tumour not able to be assessedT0: No evidence of primary tumour, ie. cancer cells seen on sputum sampling or bronchial washing onlyTis: Carcinoma in situT1: Tumour 3 cm or less, surrounded by pleura, without evidence of invasion more proximal than the lobar bronchus.T2: Tumour with any of the following features: >3cm in greatest dimensionInvolves main bronchus, 2cm or more distal to the carinaInvades visceral pleuraAssociated with atelectasis or obstructive pneumonitis, extending to the hilar region but not involving the entire lung.T3: Tumour of any size, directly invading the chest wall, diaphragm, mediastinal pleura or parietal pericardium; or tumour in the main bronchus; orin the main bronchus, less than 2cm distal to the carina, but without involvement of the carina; orwith associated atelectasis or obstructive pneumonitis of the entire lungT4: Tumour of any size, invading the mediastinum, heart, great vessels, trachea, oesophagus, vertebral body, carina; or with separate tumour nodules in one lobe, or with malignant pleural effusionRegional lymph nodes (N): NX: Regional lymph nodes not able to be assessedN0: No regional lymph node metastasisN1: Metastasis in ipsilateral peribronchial and/or ipsilateral hilar lymph nodes and intrapulmonary nodes, including involvement by direct extensionN2: Metastasis in ipsilateral mediastinal and/or subcarinal lymph nodesN3: Metastasis in contralateral mediastinal, contralateral hilar, ipsilateral or contralateral scalene, or supraclavicular lymph nodesDistant Metastasis (M) MX: Distant metastasis not able to be assessedM0: No distant metastasisM1: Distant metastasis, including separate tumour nodule(s) in a different lobe (ipsi- or contralateral).

Using this classification, non-small cell lung cancers are grouped into stages as follows:
Stage 0: TIS N0 M0Stage Ia: T1 N0 M0Stage Ib: T2 N0 M0Stage IIa: T1 N1 M0Stage IIb: T2 N1 M0, T3 N0 M0Stage IIIa: T1 N2 M0, T2 N2 M0, T3 N1 M0, T3 N2 M0Stage IIIb: any T N3 MO, T4 any N M0Stage IV: any T any N M1

Using this system, outcomes are best for patients with early stages of disease, with small tumours, no spread to lymph nodes, and no distant spread (metastasis) to other organs. Outcomes are also better for younger patients.
Overall, 5-year survival for all types of lung cancer in Australia is 11% for males and 14% for females. Survival for non-small cell lung cancer is better than for small cell lung cancer. Different subtypes of NSCLC are also associated with different survival rates. Survival is best for adenocarcinoma, followed by squamous cell carcinoma of the lung and large cell carcinoma.
Management of patients with lung cancer requires interaction from many medical specialties such as medical and radiation oncology, respiratory physicians, cardiothoracic surgeons, palliative care specialists, psychologists and physiotherapists. The main treatment modalities are surgery (such as lobectomy), chemotherapy and radiotherapy.

Surgical treatment
Surgery offers the best chance of cure, but is usually only possible with small tumours that have not yet spread (stage I or II). In some cases, lobectomy may be more appropriate than limited resection.If surgical treatment is to be given, the lymph nodes draining the tumour should be sampled and removed if the cancer has spread.

Radiotherapy
Patients with tumours which are not suitable for surgical resection can benefit from radiotherapy to the chest.Patients with early disease (Stage I or II cancer) who have had the tumour completely surgically removed do not usually need radiotherapy.

Chemotherapy
Chemotherapy can increase survival for patients with advanced cancer who are otherwise medically fit. Chemotherapy may also have improve quality of life for these patients.If chemotherapy is to be used, combination regimes (using more than one drug together) are better than single-drug regimes. Chemotherapy using platinum-based drugs produces the best results.

New classes of treatment agents, such as biological therapies, are finding a place alongside chemotherapy. Watch this site for breaking news regarding this treatment.

Palliative care
Lung symptoms commonly reported by patients with incurable lung cancer include shortness of breath from pleural effusion, coughing, or haemoptysis (coughing up blood). Pain may be from the lung tumour itself, or from spread (metastasis) to other organs, including bone. Treatment is available for all of these symptoms. In some cases, radiotherapy may be used to manage cancer pain. Spinal cord compression is a complication of cancer spread to the spine which requires urgent treatment.