LUNG CANCER

LUNG CANCER

alternative names:

Bronchial Carcinoma, neoplasia pulmonary malignant, malignant tumor of the lung.

What it is?

The lung cancer is the most common of the malignant tumors, presenting an increase per year of 2% in its worldwide incidence. Mortality for this tumor is very elevated and the prognostic of this illness is related to the phase where it is diagnosed.

How does it develop?

Smoking is the main factor of risk for the development of lung cancer. It is responsible for 90% of the cases of this tumor. More men than women develop lung cancer, but the number of cases in women is increasing, whereas the number of cases in men is falling. The risk of death for lung cancer is 22 times higher among smokers than among nonsmokers.

This pulmonary neoplasia can also be caused by chemical substances – arsenic, asbestos, beryllium, radon, nickel, chromium, cadmium and vinyl chloride, mainly found in the occupational environment. Other factors related to this tumor are dietary ( low consumption of fruits and vegetables), genetic, the chronic obstructive pulmonary illness (pulmonary mphysema and chronic bronchitis) and the family history of lung cancer. Sometimes, some individuals who have never smoked may develop this condition, the cause being unknown.

Types of lung cancer

There are, basically, two types of lung cancer, depending on how the cells appear to the examination under the microscope:
 

	non-small cells and
	small cells

Non-small cell cancers represent 80% of all the cases. These include the adenocarcinoma, the Squamous Cell Carcinoma (epidermoid) and the large cell carcinoma. Generally, the non-small cel not spread slowly to other organs of the body and it can be difficult to detect them in the early stages.

On the other hand, small cell cancers account for 20% of the cases of lung cancer. They spread very quickly to the lungs and other organs.

What does one feel?

There are many symptoms of lung cancer. However, sometimes the symptoms will be become obvious only in the advanced stage of the condition.

The signs and symptoms of lung cancer may include:
 

	persistent cough or a change in the pattern of a smoker’s cough
	shortening of breath,
	sputum with blood,
	hoarseness,
	persistent or acute chest pain when the individual breathes deeply,
	repetition pneumonias,
	wheezing

Sometimes, affected individuals may feel malaise or fatigue. There will also likely have loss of weight or appetite. The symptoms may be due to illness in the lung, its dissemination to the ganglia in the thorax or to other organs, such as the brain, liver, adrenal glands (one on each side, just above each kidney) or bones.

How does the doctor make the diagnosis?

The onset of any signs or symptoms of respiratory illness may take the patient to seek a general practitioner or specialist. He will be able start an investigation including, usually, an X-ray of the thorax, whereby the doctor will be able to detect a suspected injury. A computerized scan or magnetic resonance of the thorax will provide a more detailed information about the lesion.

At this point, cytopathological analysis of sputum be required, since it is a simple test capable to confirm the presence of the lung cancer. However, the absence of malignant cells in the sputum certainly does not exclude the disease. The test sample is usually collected in the morning, taking the patient to expectorate in a wide-mouth container. The material shoudl be sent without delay for microscopical analysis in the laboratory

There are other procedures aiming to make the diagnosis of the illness or to clarify its extension, including:
 

	fibrobronchoscopy
	needle-punture of the lung
	Thoracentesis and
	Thoractomy

Fibrobronchoscopy is an examination method in which a flexible fibre-optics device endowed with an intrumentation cana, whereby are passed forceps and bruhes, is introduced through the mouth or nostril, reaching into the lung. Inside the lung a washing of the injured area is performed (bronchial washing) and a small brush is rubbed against the injury or next to it. Analyses are made with the brushings. Small pieces of the lesion are collected by means of forceps. All the material obtained (washings, brushings and bronchial biopsy) is sent for analysis in the pathology laboratory. The findings of the fibrobronchoscopy are more important in the cases of central tumors – which are more within reach of the device.

Another method to help in the diagnosis of the disease is the needle puncture of the lung through the thoracic wall. The doctor, with the aid of imaging tests to guide the puncture, aspirates the tumoral lesion or removes a sample of the injured tissue by means of a cutting needle. This diagnosis method is used only in the cases in which the tumor is localized peripherically. That is, when the injury is right next to the wall of the thorax.

Thoracentesis is the removall of the fluid that is in the pleural cavity (between the lung and the thoracic wall). After anesthesia (usually local), the fluid is then apirated by means of a serynge connected to a needle. It is an alternative for the diagnosis, since some lung tumors can be manifested in this form. The fluid is then sent for laboratory analysis.

Frequently, there are cases whose diagnosis comes through the surgical removal of disease-affected ganglia – whether they be in the thorax, neck or other less usual sites.

Mediatinoscopy is a surgical procedure that approaches the mediastinum (space situated between the two lungs) and that frequently is the primary site for the progression of the illness. Lung tumors, most of the time, spread to the lymph nodes the mediastinum, and then to other organs,as bones, liver, brain and adrenal glands. Therefore, in addition to confirm the bronchial carcinoma and its histologic type (type of tissue), mediatinoscopy can assist in the staging of the illness – showing whether it is an advanced condition or not. It helps to define the patient's prognostic.

In some cases, the surgical incision of the thorax (thoracotomy) is necessary for the confirmation of lung cancer. These are cases in which the patient should be hospitalized.

How is it treated?

Malignant tumors of the lung can be treated with surgery, chemotherapy or radiotherapy. Also, these therapeutical modalities can be combined.

Radiotherapy is frequently is used adjunctively with surgery. There are several cases in which, rather than performing surgery, radiotherapy is combined with chemotherapy.

Chemotherapy – medication-based treatment to fight the tumors – it is also used adjunctively with surgery, whether to decrease tumors' size, facilitating the surgery,or to help to destroy the cancerous cells in the site of the tumor.

Another alternative is the photodynamic therapy, in which medications are injected into the body and, later, they are activated by means of laser beams.

The doctor will decide the treatment according to the cellular type of the tumor, its staging, as well as to the the patient's conditions

The only effective way to prevent it is quitting smoking.

While this is far less frequent, an individual who has never smoked may, at some point in life, develop a malignant lung tumor