Histological types of lung cancer

There are two major types of lung cancer:

Non-small cell lung cancer – This type of cancer is much more common. It usually spreads to different parts of the body more slowly than small cell lung cancer.

• squamous cell carcinoma
• adenocarcinoma,
• large cell carcinoma

Small cell lung cancer- small cell lung cancer also called oat cell cancer, accounts for about 20% of all lung cancers.

Diagnosis of lung cancer

Unfortunately, lung cancer is usually diagnosed too late for treatment to be possible. In over half of people with lung cancer the disease has already spread at the time of the diagnosis.

Early diagnosis is difficult because many of the common symptoms of lung cancer are similar to those of chronic obstructive pulmonary disease.

X-ray examination

The first investigation of lung cancer should be a chest X-ray. However, this method can't detect all tumors because it needs to be at least a centimeter in diameter to be detectable by an ordinary X-ray. 

Blood tests

Some simple blood tests and further examinations may also be carried out.

Bronchoscopy

This is a very good diagnostic tool and it represents a direct inspection of the inside of the breathing tubes with a thin instrument called bronchoscope. It is all done using local anaesthetic and is the best method for the diagnosis of tumors in the bronchi in the centre of the chest.

Biopsy

Depending on the site of the cancer, a biopsy will be obtained either by a bronchoscopy or a needle biopsy.

Sample of sputum

A sample of sputum, the material coughed up from the respiratory tract, will also be examined for cancer cells.

CT-scan

A CT scan provides more information about how much the tumor may have spread. 

Metastatic lung cancer

The lung is a common place for metastasis from tumors in other parts of the body. These cancers, however, are identified by the site of origin, i.e., a breast cancer metastasis to the lung is still known as breast cancer. The adrenal glands, liver, brain, and bone are the most common sites of metastasis from primary lung cancer itself.

Treatment of lung cancer

Treatment of lung cancer can depend on the size, location and extent of the tumor, and  general health of the patient. There are many treatments, which may be used alone or in combination. These include:

Surgery

Surgery may cure lung cancer but it is used in limited stages of the disease. The type of surgery depends on where the tumor is located in the lung. 

Radiation therapy

Radiation therapy is a form of high energy X-ray that kills cancer cells. It is used:

• In combination with chemotherapy and sometimes with surgery.
• To offer relief from pain or blockage of the airways.

Chemotherapy

Chemotherapy is the use of drugs that are effective against cancer cells. Chemotherapy may be injected directly into a vein or given through a catheter, which is a thin tube that is placed into a large vein and kept there until it is no longer needed. 

Chemotherapy may be used:

• In conjunction with surgery.
• In more advanced stages of the disease to relieve symptoms.
• In all stages of small cell cancer.