Most lung cancers (83%) are associated with, and probably caused by, cigarette
smoking. The more cigarettes smoked per day and the earlier the age at which
smoking started, the greater the risk of lung cancer. Second-hand smoke has
also been shown to increase the risk. Government surveys show that as many as
3,000 people each year develop lung cancer from second-hand smoke. High
levels of pollution, radiation, and asbestos exposure may also increase the risk.
Cooks and chemists also have an increased risk.
Lung cancer begins by cellular changes in the bronchial epithelial cells and can
invade adjacent tissues before symptoms are noticed.
There are many types of lung cancer, but most can be categorized into two basic
types, small cell and nonsmall cell. In general, the small cell type has usually
spread by the time of diagnosis and is treated by chemotherapy and/or radiation
therapy. The nonsmall type may not have spread at the time of diagnosis, and
surgical resection of this type may be possible. Metastatic lung cancer (the
spread of cancer) can occur to almost any area of the body with common sites
being the brain, bone, bone marrow, and liver. Treatment is based on
determining the cellular type of the cancer, and by staging, which determines the
size of the primary tumor and the extent of spreading to lymph nodes or sites of
metastasis. Lung cancer is the leading cause of death in both men and women.
The peak incidence occurs between 55 and 65 years old. The incidence is 1 out
of 1,000 people.
If you smoke, stop smoking. Try to avoid second-hand smoke. Routine
screening of high-risk individuals (men over 45 years old smoking 40 or more
cigarettes a day) may help detect the disorder early. Yes. There are ways to improve the chance of early detection. Because lung cancers often spread
very early, current methods of early detection have not had much effect on cure rates. On the other hand, early detection and treatment can result in a cure for some patients and can extend life for others. For this reason, prompt medical attention to symptoms is very important. If you have any of the following problems, see a doctor right away:
A cough that does not go away
Weight loss and loss of appetite
Bloody or rust-colored sputum (spit or phlegm)
Shortness of breath
Fever without a known reason
Recurring infections such as bronchitis and pneumonia
These symptoms may be the first warning of a lung cancer. Some of these symptoms can also result from other causes or from noncancerous diseases of the lungs, heart, or other organs. But, seeing a doctor is the only way to find out whether or not your symptoms are due to a lung cancer. Since symptoms of lung cancer often do not appear until the disease is advanced, only about 15% of the lung cancer cases are found in the early stages, before it has spread. The five-year survival rate for people with lung cancer is 48% if there is no evidence of cancer in lymph nodes at the time of diagnosis. In many of these patients, spread of their cancer has already occurred but could not be detected by current medical tests. In contrast, the five-year survival rate is 14% for all lung cancer stages combined.
Staging is a process that tells the doctor how widespread the cancer may be. It will show if the cancer has spread and how far. The treatment and outlook for cancer depend, to a large extent, on its stage.
Staging of non-small cell lung cancer
The most common system used to stage non-small cell lung cancer is the TNM system. T stands for tumor (its size and how far it has spread within the lung and to nearby organs), N stands for spread to lymph nodes and M is for metastasis (spread to distant organs). In TNM staging, information about the tumor, lymph nodes and metastasis is combined and a stage is assigned to specific TNM groupings. The stage is described by a number in Roman numerals from I to IV.
Stage 0: Lung cancer is found only in the layer of cells lining the air passages. It has not invaded other lung tissue. This stage is also known as carcinoma in situ. The cancer has not spread to lymph nodes or other organs. Lung cancer in this early stage is too small to be found by x-rays.
Stage I: Lung cancer has spread from the lining of the air passages into other lung tissue. It has not spread to nearby lymph nodes. The membranes which surround the lung (visceral pleura) may be involved. In this stage, the cancer is not closer than 2 cm (about 3/4 inch) from where the windpipe branches into the right and left bronchi. There may be some clogging of the airways by the cancer, but this has not yet caused the lung to collapse or pneumonia to develop.
Stage II: Lung cancer has spread to lymph nodes within the lung or at the point where the bronchus enters the lung (bronchial or hilar lymph nodes). The thin membranes which surround the lung may be involved. The cancer is not closer than 2 cm (about 3/4 inch) from where the windpipe branches into right and left bronchi. There may be some clogging of the airways, but this has not yet caused the lung to collapse or pneumonia to affect the whole lung.
Stage III: Stage III lung cancer is further divided into Stage IIIA and Stage IIIB
Stage IIIA: As in stage II, the cancer may have spread to the membranes surrounding the lungs (visceral pleura) and/or to bronchial or hilar lymph nodes. In addition, the cancer has spread into one or more of the following:
The mediastinal lymph nodes (the lymph nodes in the space between the two lungs) on the same side as the original cancer. These are classified as N2 nodes in TNM staging.
The carinal lymph nodes (the lymph nodes near the point where the windpipe branches into the right and left bronchi). These are classified as N2 nodes in TNM stages. The chest wall, the diaphragm, the membranes surrounding the space between the two lungs (the mediastinal pleura), or the membranes of the sac surrounding the heart (parietal pericardium).
Also, in Stage IIIA the cancer may be found in a main bronchus closer than 2 cm (about 3/4 inch) from where the windpipe branches into right and left main bronchi. There may be clogging of the airways, but this has not caused the lung to collapse or pneumonia to affect the whole lung.
Stage IIIB: In this stage the cancer has spread more extensively into nearby organs like the heart or into large blood vessels (arteries and veins) going into or leaving the heart. It may also have spread into the windpipe, the esophagus (the tube connecting the throat to the stomach) or the backbone. Also, there may be fluid containing cancer cells in the space surrounding the lungs. This is called a pleural efffusion. There may also be cancer in the lymph nodes farther away from the original tumor, for example, in nodes on the other side of the chest or above the collar bone (N3nodes).
Stage IV: The lung cancer has spread to distant organs such as the brain, bones, or the liver. As noted earlier, the treatment plan for lung cancer is based on the type and stage. Treatments could include surgery, radiation therapy, or chemotherapy. Survival rates vary greatly for different stages.
Staging of small cell lung cancer
For small cell lung cancers, a two stage system is most often used. These are, "limited stage" and "extensive stage." Limited stage usually means that the cancer is only in one lung and in lymph nodes on the same side of the chest. Spread of the cancer to the other lung, to lymph nodes on the other side of the chest , or to distant organs indicates extensive disease. Many doctors consider small cell lung cancer which has spread to
the fluid around the lung to be an extensive stage.
Small cell lung cancer is staged in this way because it helps separate tumors which can be treated more effectively with radiation therapy from those which cannot. About two-thirds of the people with small cell lung cancer will have extensive disease at the time their cancer is first found.
In recent years, much progress has been made in treating lung cancer with surgery, radiation therapy, and chemotherapy. Surgery has been improved, and more is known about the best way to combine drugs to treat different types of cancer.
After the disease is found and staged, the cancer care team will recommend a treatment plan. While this is an important decision, it is also important to take time and think about all of the choices. In choosing a treatment plan, factors to consider include the patient's overall physical health, the nature of the disease, and anything else that makes that person unique.
It is often a good idea to seek a second opinion. A second opinion can provide more information and help the patient feel good about the treatment plan that is chosen. Some insurance companies require a second opinion before they will agree to pay for treatments.
Types of Treatment for Lung Cancer
Depending on the type and stage of a lung cancer, surgery may be used to remove the cancer and some of the surrounding lung tissue. If a section (lobe) of the lung is removed, it is called a lobectomy. If the whole lung is removed , the surgery is called a pneumonectomy. Removing part of a lobe is known as segmentectomy or " wedge resection. "
Chemotherapy uses anticancer drugs that are given into a vein or by mouth. These drugs enter the bloodstream and reach all areas of the body, making this treatment useful for cancer that has spread or metastasized to organs beyond the lung. Depending on the type and stage of lung cancer, chemotherapy may be given as the main (primary) treatment or as an addition (adjuvant) to surgery. Chemotherapy for lung cancer generally uses a combination of several anticancer drugs. These drugs kill cancer cells but can also damage some normal cells. Therefore, careful attention is given to avoiding or minimizing side effects.
The side effects of chemotherapy depend on the type of drugs, the amount taken, and the length of time they are taken. These may include upset stomach and vomiting, a loss of or increase in appetite, loss of hair and mouth or vaginal sores. There can also be an increase in infections, bleeding, low iron in the blood (anemia), tiredness, changes in the menstrual cycle, and damage to the ovaries or testicles which result in not being able to have children (infertility).
There is also the possibility of developing a very serious disease of white blood cells known as acute myeloid leukemia (AML). The chances of this are greatest when higher than standard doses are needed to treat the cancer. Research is comparing the risk of this type of treatment with the benefits.
Most of these effects (except infertility) stop when the treatment is over. Anyone who has problems with side effects should talk with their doctor. There are often ways to lessen the
Radiation therapy uses high energy radiation to kill cancer cells. External beam radiation therapy uses radiation delivered from outside the body that is focused on the cancer. This is the type of radiation therapy most often used to treat lung cancer. Interstitial radiation therapy uses a small pellet of radioactive material placed directly into the cancer. Radiation therapy is sometimes used as the main (primary) treatment of lung cancer in some patients, especially those whose general health is too poor to undergo surgery. After surgery, radiation therapy can be used to kill very small deposits of cancer that cannot be seen and removed during surgery. Radiation therapy can also be used to palliate, or ease, symptoms of lung cancer such as pain, bleeding, difficulty swallowing, and problems caused by brain metastases.
Side effects of radiation therapy may include mild skin problems, upset stomach, loose bowels, or tiredness. Often these go away after a short while. Radiation may also make the side effects of chemotherapy worse. Chest radiation therapy may cause lung damage and lead to breathing difficulty and shortness of breath. Side effects of brain radiation therapy usually become most serious one or two years after treatment, and include headaches and difficulty with thinking.
As mentioned before, talk with your doctor about these since there are ways to help.