What is Lung Cancer: What is Lung Cancer

Lung cancer usually starts in the lining of the bronchi, but can also begin in other areas of the respiratory system, including the trachea, bronchioles, or alveoli.
Lung cancers are believed to develop over a period of many years.
Nearly all lung cancers are carcinomas, a cancer that begins in the lining or covering tissues of an organ.
The tumor cells of each type of lung cancer grow and spread differently, and each type requires different treatment. More than 95 percent of lung cancers belong to the group called bronchogenic carcinoma.
Once uncommon, the surge in smoking of the 20th century has contributed to a tremendous rise in the incidence of lung cancer. Lung cancer is now the leading cause of cancer death in men and second leading cause of cancer death in women worldwide. On the bright side, with widespread awareness of the risks of smoking, many hope these numbers will decrease in the future.

Non-small cell lung cancer is more common than small cell lung cancer. The three main kinds of non-small cell lung cancer are named for the type of cells in the tumor:

o Squamous cell carcinoma, also called epidermoid carcinoma, is the most common type of lung cancer in men. It often begins in the bronchi, and usually does not spread as quickly as other types of lung cancer.

o Adenocarcinoma usually begins along the outer edges of the lungs and under the lining of the bronchi. It is the most common type of lung cancer in women and in people who have never smoked.

o Large cell carcinomas are a group of cancers with large, abnormal-looking cells. These tumors usually begin along the outer edges of the lungs.

Small cell lung cancer, sometimes called oat cell cancer because the cancer cells may look like oats when viewed under a microscope, grows rapidly and quickly spreads to other organs.

What are the symptoms of lung cancer?

Lung cancer usually does not cause symptoms when it first develops, but symptoms often become present after the tumor begins growing. A cough is the most common symptom of lung cancer. The following are the other most common symptoms for lung cancer; however, each person may experience symptoms differently:

constant chest pain
shortness of breath
wheezing
recurring lung infections, such as pneumonia or bronchitis
bloody or rust colored sputum
hoarseness
swelling of the neck and face caused by a tumor that presses on large blood vessels near the lung
pain and weakness in the shoulder, arm, or hand caused by a tumor that presses on certain nerves near the lung
fever for unknown reason

Like all cancers, lung cancer can cause:

fatigue
loss of appetite
loss of weight
headache
pain in other parts of the body not affected by the cancer
bone fractures

What are the risk factors for lung cancer?

A risk factor is anything that increases a person's chance of getting a disease such as cancer. Different cancers have different risk factors. Several risk factors make a person more likely to develop lung cancer:

Smoking is the leading cause of lung cancer, with more than 90 percent of lung cancers thought to be a result of smoking.

Additional risk factors include:

second-hand smoke - breathing in the smoke of others.
smoking marijuana cigarettes, which:

contain more tar than tobacco cigarettes.

are inhaled very deeply.

are smoked all the way to the end where tar content is the highest.

Because marijuana is an illegal substance, it is not possible to control whether it contains fungi, pesticides and other additives.

recurring inflammation, such as from tuberculosis and some types of pneumonia.

asbestos exposure.

talcum powder.
While no increased risk of lung cancer has been found from the use of cosmetic talcum powder, some studies of talc miners and millers suggest a higher risk of lung cancer and other respiratory diseases from their exposure to industrial grade talc. Talcum powder is made from talc, a mineral which in its natural form may contain asbestos, although by law, all home-use talcum products (baby, body, and facial powders) have been asbestos-free.

cancer-causing agents in the workplace, including:

radioactive ores such as uranium

arsenic

vinyl chloride

nickel chromates

coal products

mustard gas

chloromethyl ethers

radon - a radioactive gas that cannot been seen, tasted or smelled. It is produced by the natural breakdown of uranium.

family history

personal history of lung cancer

vitamin A deficiency
People who do not get enough vitamin A are at increased risk of lung cancer. Taking too much vitamin A may also increase lung cancer risk.