indiacancer.org - Lung Cancer

Lung Cancer

		What are the lungs?
		What is lung cancer?
		How does lung cancer present?
		How is lung cancer detected?
		What are staging and grading?
		How is lung cancer treated?
		What are the side effects of treatment for lung cancer?
		What are the possible causes of lung cancer?
		Mesothelioma HQ: categorized resource directory for everything about mesothelioma.

What are the Lungs?

The lungs are multilobed, bilateral, spongy organs involved in the process of respiration and which lie enclosed within the chest cavity. The right lung has three sections, called lobes; it is a little larger than the left lung, which has two lobes. When we breathe in, the lungs take in oxygen, which our cells need to live and carry out their normal functions. When we breathe out, the lungs get rid of carbon dioxide, which is a waste product of the body's cells.

The Trachea and The Bronchi

What is Lung cancer?

The Chest Cavity

Lung cancer is the uncontrolled growth of abnormal cells in one or both of the lungs. While normal lung tissue consists of cells programmed by nature to reproduce and develop into healthy, well-formed lungs, these abnormal cells reproduce and develop into cancer rapidly and disrupt this natural programming. Tumors will then form and clog the lung, making it difficult for the lung to work properly.

Lung cancer almost always begins in one lung and then spreads to lymph nodes or other tissues in the chest, including the other lung. Lung cancer can also metastasize throughout the body, spreading to the bones, brain, liver, or other organs. Cancers that spread are still considered part of the original cancer; in other words, if a brain tumor results from lung cancer, it is still called metastatic lung cancer.

Since the lungs are large, cancers can grow in them for many years before they are detected. In fact, lung cancers can easily spread outside the lungs without causing any symptoms. Even when a major symptom appears, such as a persistent cough, it is often mistaken for a cold, bronchitis, or allergies.

There are more than a dozen different kinds of lung cancer. They differ by the type of cells found in the tumor formed by the cancer. The two main types of lung cancer are small cell and nonsmall cell. These two types account for about 90% of all cases of lung cancer. The names do not refer to the size of the tumor so much as to the kind of cells that make up the tumor.

Small cell carcinomas, which represent about 15% of all lung cancer cases, typically begin in one of the breathing tubes (the bronchi or the smaller bronchioles). This type of lung cancer grows fairly rapidly and consists of a small, round cells, often called oat cells because of their shape.

Nonsmall cell lung cancers (about 75 per cent of all lung cancers) occur in three forms:

Epidermoid carcinoma is located in the lining of the bronchial tubes. This is the most prevalent type of lung cancer in men. Epidermoid carcinoma (also called squamous cell carcinoma) tends to spread less quickly than other forms of lung cancer.

Adenocarcinoma is found in the mucus glands of the lung. This is the most common type of lung cancer in women and for people who have not smoked. People with adenocarcinoma often suffer from phlebitis and an increased tendency to get blood clots.

Large cell carcinomas form near the surface (outer edges) of the lungs. These types of cancerous tumors can grow quite rapidly, and have often spread before they are diagnosed.

The above types of lung cancer account for about 90 per cent of all lung cancers. The remaining 10% include a number of uncommon types, including bronchoalveolar cancer, a slow growing form of lung cancer that occurs most often in older people and tends to have a better outcome (or prognosis).

How does lung cancer present?

Symptoms of lung cancer include:

The Trachea and the Lungs

A persistent cough.

Coughing up blood.

Unusual, unexplained fatigue.

Swelling of the neck and face.

Shortness of breath.

Repeated pneumonia or bronchitis.

Loss of appetite and loss of weight.

Hoarseness.

Persistent chest, shoulder, or back pain.

These symptoms do not always appear in the early stages of lung cancer. Sometimes doctors discover the cancer from taking a routine chest X-ray. More often, though, the cancer is detected after a growing tumor causes symptoms to occur – a cough, swelling in the neck and face, or continuous pain in the chest, shoulder, or back.

If the cancerous tumor is in an air passage or the throat, it can make breathing more difficult, as a result, a person may experience shortness of breath, hoarseness, or even cough up blood, due to irritation of the air passage. Because a great deal of energy is being spent in fighting the cancer, the body’s resistance to other diseases may drop. For this reason, people with lung cancer are often prone to bouts of pneumonia or bronchitis, brought on by an irritation of an infection in the lungs.

Some symptoms, such as fatigue and loss of appetite, may not seem to be related to the tumor itself. Most likely, they result from the metastases, or the spread of the cancer to other parts of the body. Your symptoms will depend on which organs have been affected by the cancer. If lung cancer spreads to the brain, for example, it can cause nerve damage that may have a dramatic effect on a person’s thinking, coordination, or other mental operations.

Cancer also changes the body’s metabolism. People with cancer use the calories from foods much less efficiently than they did before they got cancer, so they usually need to eat more to maintain their weight.

How is lung cancer detected?

Doctors can detect lung cancer through a number of different tests.

The first step is usually a series of chest X-rays.

Sputum cytology is the microscopic examination of the cells in the thick fluid a patient coughs up from the lungs or breathing tubes. This procedure can discover lung cancers not found on X-rays. However, sputum cytology does not show where tumors are located, so follow up tests are usually necessary.

CAT (Computer-assisted tomography) scans and MRIs (Magnetic Resonance Imaging) are more sophisticated tests that use computerized pictures to develop a three dimensional image of the tumor. Because CAT scans and MRIs can show the lungs, lymph nodes, or other parts of the body with much greater precision than X-rays, they can also pinpoint whether the cancer has spread from the lung to other parts of the chest or body.

A biopsy is usually ordered when a tumor is suspected to be cancerous. For this test, tissue is removed from the tumor either by inserting a long needle into the lung, or by operating to remove part or all of the tumor. Examination of the tissue under a microscope will reveal whether the tumor cells are cancerous and, if so, what type of cancer they are.

If the tumor is believed to originate from the tracheo-bronchial tree, or the airways traversing the lungs, the doctor will perform a bronchoscopy, in which a special, fiberoptic, flexible tube will be introduced through the nose and passed into the patient's airways. This 'scope has a self illuminating system and a biopsy port as well. Thus, the doctor can visualise any tumors present and also biopsy them. The procedure is done with the patient awake, with local anaesthesia to the main windpipe or trachea, to prevent him coughing.

What are staging and grading?

These are terms with which you must become familiar, if you are dealing with any form of cancer.

When we stage a cancer, we try to establish carefully the degree of spread of the cancer and if indeed there is spread, to what extent and involving which organs.

The grading of a cancer is a microscopic issue, in which the pathologist lets you know how aggressive this particular type of cancer is; well differentiated means less aggressive, moderately differentiated intermediately aggressive and poorly differentiated very aggressive.

Both grading and staging help your clinician to establish the prognosis or how serious your disease is and what is going to be the likely outcome.

Staging may require additional imaging tests such as CT Scan, MRI, Sonography, Bone scan or chest X-ray.

Before selecting the best course of treatment for you, your doctor must first evaluate the stage of your lung cancer.

Here are the four stages of lung cancer:

Stage I: The cancer is located only in the lung, and has not spread to the lymph nodes. This is the least advanced stage. The treatment recommended for Stage I lung cancer is surgical removal of the tumor. This is successful for most patients (while this is very encouraging, unfortunately most people are not diagnosed at this stage, since the symptoms are often not pronounced enough for anyone to suspect cancer).

Stage II: The cancer has spread to the nearby lymph nodes found in the chest near the lungs. Lymph nodes are small, bean-shaped structures where cells are stored; nodes can trap cancer cells or bacteria traveling through the body. Depending on the size of the nodes on a CAT scan, your doctor may recommend an additional test called a mediastinoscopy. This test is a minor operation to examine the lymph nodes in the chest and perform a biopsy on them. A mediastinoscopy can determine whether the nodes actually have cancer in them, or are enlarged only because of inflammation associated with cancer.

If this procedure shows only minimal traces of cancer in these lymph nodes, the treatment recommendation would most likely be surgery on the main tumor followed by radiation and or chemotherapy for the lymph nodes.

Stage III: The cancer is found in the lymph nodes in the middle of the chest away from the lungs. Stage III lung cancer has two types.

If the cancer is a single tumor, or mass, it is called stage III-A. Most doctors will recommend beginning treatment for stage III-A with chemotherapy, or a combination of anti cancer drugs, and radiation. Then, depending on how well the treatment has worked, they may remove the remaining tumor with surgery.

This combination of chemotherapy with surgery or radiation offers the best possibilities for cure. If the cancer in the chest has spread to more than one area, it is called stage IIIB.

Most doctors do not recommend surgery for Stage II-B. A combination of chemotherapy and radiation is usually of the greatest benefit.

Stage IV: This is the most advanced stage of lung cancer. This is when the cancer has spread to a distant part of the body – for example, your liver, bones, brain, or some other organ. For stage IV, most doctors are in agreement that chemotherapy is the most effective treatment. Often, different combinations of chemotherapy drugs will be used, to see which will be the most effective on your particular form of cancer.

How is lung cancer treated?

Doctors spend a great deal of time determining what stage of lung cancer you have, so that they will be able to prescribe the most effective form of treatment. Below is a review of the treatment recommendations for each stage. Keep in mind that each case of cancer is different. Your exact treatment may vary from what you read here.

Stage I: Surgical removal of the tumor.

Stage II: Surgical removal of the tumor and lymph nodes, followed by radiation and/or chemotherapy.

Stage III-A: Chemotherapy and Radiotherapy to shrink the tumor, followed by surgery to remove the remaining tumor.

Stage III-B: A combination of chemotherapy and radiation therapy to shrink the tumor.

Stage IV: A combination of chemotherapy drugs to find the most effective ones.

Besides local therapy, the best attempt to control cancer cells circulating in the body and lodged at places other than the lung is by using systemic therapy (therapy which affects the entire systems of the body) which is in the form of injections or oral drugs. This form of treatment is called chemotherapy.

This form of treatment is given in a cyclical manner (each set of drugs is repeated usually after every 3-4 weeks).

Chemotherapy can also be used in combination with surgery, radiotherapy or both, either before or after.

The alternative local therapy to surgery is radiation therapy. This involves the use of high energy, penetrative rays to destroy cancer cells. It also affects cancer cells only in the zone treated. Radiation therapy is usually employed for palliation i.e. control of symptoms alone in an advanced cancer.

Radiation therapy can also be used in adjunct to surgery or chemotherapy, either before or after.

Radiotherapy, after initial planning, usually takes just 5 to 10 minutes per day, 5 days a week for about 6 weeks. This time period is flexible depending upon the modality of radiation used.

What are the side effects of treatment for lung cancer?

	Unfortunately, treatment for cancer does cause damage to healthy tissues as well, the tissue involved being dependent upon the modality of treatment selected. This results in certain side effects. Please ask the clinician about any possible side effects before any form of treatment commence. If you have either Stage I or Stage II lung cancer, the surgery to remove your cancerous tumor is still a major operation, and it will probably take you many weeks, or even months, to regain your strength and energy. Recovery will vary from person to person, depending on your age, your health, and other factors. The muscles of your chest and arm on the side of your surgery, may become weak and require special exercises to regain strength. Unfortunately, some pain and discomfort are common after such surgery. Your doctor or nurse can help you manage the pain with medicines and other means. Air and fluid often collect in the chest after lung surgery. To help relieve this, patients are helped to turn, cough and breathe deeply. This helps you expand the remaining lung tissue, get rid of excess air and fluid, and recover more quickly. Your doctor will generally prescribe respiratory physiotherapy as well. This involves exercises and treatments to keep the lungs expanded and to prevent fluid buildup. At first, you may feel shortness of breath after surgery, since there is now less lung tissue to supply the body with oxygen. For a while, you may also have to limit your physical activities. Gradually, however, the remaining lung tissue will expand somewhat, making it easier to breathe. The various drugs used in chemotherapy cause a varied spectrum of side effects. The severity and variability of these symptoms are very individualistic, changing from patient to patient. Some of the common side effects are:
		Infections.
		Skin rashes.
		Loss of hair.
		Diarrhea.
		Vomiting.
		Tingling and numbness in the fingers and toes.
		Hearing loss.
	Most are temporary and recede after therapy is over. Hair growth gradually starts after cessation of chemotherapy. The medical oncologist (chemotherapist) will usually be able t reduce he severity and spectrum of these side effects. The psychology of the patient is very important during therapy. The better psychologically prepared the patient is, the better are his or her chances of having decreased side effects. The patient should drink large quantities of liquids while therapy is in progress, and preferably avoid uncooked or raw food. Water for drinking should be filtered or boiled. Any relative or person who has any infection such as common cold should be asked to desist from coming close to the patient. The effects of radiation depend on the dose of radiation, the size of the area radiated, and the number and size of each fraction employed. The commonest side effect is that of extreme fatigue. Although bed rest is good, most radiotherapists advise the patients to be as mobile as possible. Another common problem is that of radiation dermatitis, in which the skin covering the radiated area becomes red, dry, itchy and may show signs of scaling off. This will slowly settle as radiation ceases, but there may be a permanent 'bronzing' of the skin. Radiation also causes nausea and vomiting, diarrhea and urinary discomfort. There may also be a fall in the white blood cells, which are needed by humans to fight infections. Usually, the radiotherapist can suggest the drugs and diet necessary to alleviate such problems.

What are the possible causes of lung cancer?

Most people who get lung cancer have been cigarette smokers. However, not all smokers develop lung cancer. In some cases, too, people who have never smoked get lung cancer.

A person’s risk of developing lung cancer is increased from exposure to certain carcinogens (harmful substances like asbestos or radon gas).

Even if you are diagnosed with lung cancer, it is very important that you stop smoking if you have been a smoker. Quitting smoking will have an impact on the effectiveness of your treatment.