Cancer Types

Primary lung cancer is a disease that starts in the lungs. There are three main types:

Small cell lung cancer: This is also called 'Oat Cell' lung cancer because of the distinctive shape of the cells. It is a rapidly growing cancer that spreads very early to other organs. It is generally found in people who are heavy smokers, and is responsible for 20% to 25% of all lung cancer cases.

Non-small cell lung cancer: There are three types of non-small cell lung cancer. These are grouped together because they behave in a similar way and respond to treatment differently to small cell lung cancer. The three types are: squamous cell carcinoma, adenocarcinoma and large cell carcinoma.

Squamous cell cancer is the commonest type of lung cancer, accounting for 33% of all lung cancer cases. It develops from the cells that line the airways. It often begins in the bronchi and may remain in the chest without spreading for longer periods than the other types.

Adenocarcinoma also develops from the cells that line the airways, but from a specialised type that produces mucus (phlegm).

Large cell lung cancer is named after the large and rounded shape of the cancerous cells.

Mesothelioma: A rare type of cancer that affects the covering of the lung called the pleura. It is often caused by exposure to asbestos.

Secondary lung cancer is cancer that has started elsewhere in the body and spread to the lungs.

What are the symptoms?

A cough is a common symptom and is likely to occur when a tumour grows and blocks an air passage. Another symptom is chest pain, which feels like a constant ache that may or may not be related to coughing.

Other symptoms may include shortness of breath, repeated pneumonia or bronchitis, coughing up blood, hoarseness or swelling of the neck and face.

In addition, there may be symptoms that do not seem to be at all related to the lungs. These may be caused by the spread of lung cancer to other parts of the body. Depending on which organs are affected, symptoms can include headache, weakness, pain, bone fractures, bleeding or blood clots.

Symptoms may also be caused by hormones that are produced by lung cancer cells. For example, certain lung cancer cells produce a hormone that causes a sharp drop in the level of salt (sodium) in the body. This can lead to mental confusion and even a coma.

Like all cancers, lung cancer can also cause fatigue, loss of appetite and loss of weight.

How is lung cancer treated?

Treatment depends on the type of cancer cells, the location of the tumour and whether or not the cancer has spread. It is also tailored to a patient's medical history and general health.

There are three basic ways to treat lung cancer: surgery, radiation therapy and chemotherapy.

Small cell lung cancer spreads quickly to distant parts of the body. Often these secondary tumours cannot be found by routine tests. Therefore, treatment with surgery or radiation therapy to the chest is usually not effective in controlling small cell lung cancer.

Patients with small cell lung cancer are commonly treated with a combination of several anti-cancer drugs or with anti-cancer drugs plus radiation to the chest.

The radiation is directed to the original (primary) tumour in the lungs, while chemotherapy is used to reach tumours in other parts of the body.

Patients with non-small cell lung cancer generally can be divided into three groups.

Surgery to remove part or the whole of a lung can be used on some patients whose cancer is only in the lung.

Radiation therapy may be used to treat patients in this group who cannot have surgery because of other medical problems.

Radiation to the chest is commonly used in patients where the cancer has spread to nearby tissue or lymph nodes.

The third group includes patients whose cancer has spread to distant parts of the body. Radiation therapy and chemotherapy are used to shrink the cancer and to relieve symptoms.

Does treatment have side effects?

It is rarely possible to limit the effects of cancer treatment so that only cancer cells are destroyed; normal, healthy cells may be damaged at the same time.

For this reason, many patients experience unpleasant side effects while they are having cancer treatments.

Lung surgery may be associated with significant blood loss and damage to lung tissue.

In such cases, patients may have difficulty breathing and can sometimes become drowsy.

Radiation therapy can cause unusual tiredness, pain on swallowing and skin reactions in the area being treated.

Chemotherapy affects not only cancer cells but also other rapidly growing cells, such as blood cells, hair cells and cells that line the digestive tract.

As a result, the patient may have side effects such as anaemia, an increased risk of infection or bleeding, hair loss, nausea and vomiting. Fatigue also may occur during treatment with anti-cancer drugs.

Loss of appetite can be a serious problem for cancer patients.

What is the outlook?

The outlook for a person with lung cancer depends on the type of cancer, the stage of the disease and the patient's age, general health and response to treatment.

The one-year survival rate for lung cancer is up from 32% in 1973 to about 40%. This increase is largely a result of better methods of surgery and some progress in chemotherapy and radiation therapy.

The five-year survival rate for all stages of lung cancer is 14%.