Overview
Lung cancer is the uncontrolled growth of abnormal cells in one or both of the lungs. Currently lung cancer is the most commonly diagnosed cancer and the leading cause of cancer death in Canada with approximately 22700 new cases each year and 19300 deaths. Most lung cancer is caused by smoking. There are two major types of lung cancer: non-small cell lung cancer and small cell lung cancer. Each type of lung cancer grows and spreads in its own way and is treated differently.
Non-small cell lung cancer is the most common type of lung cancer. It generally spreads more slowly than some other lung cancers. There are three types of non-small cell lung cancer which are named for the type of cells in which the cancer develops: - adenocarcinoma
- large cell carcinoma
- squamous cell carcinoma
Small cell lung cancer is less common but spreads faster than non-small-cell lung cancer and is more likely to affect other organs in the body. There are also three types of small cell lung cancer: - combined small cell carcinoma
- mixed small cell/large cell
- small cell carcinoma
Symptoms
The five-year survival rate for men diagnosed with lung disease is 14 percent. Those who are diagnosed early have a better chance. Unfortunately cancer symptoms are often the first sign that there's a problem. But keep in mind that having these symptoms does not necessarily mean you have lung cancer. Many people especially smokers experience these symptoms from time to time. However if you do experience any of the following symptoms see your doctor immediately. - cough or a change in your existing cough
- coughing up blood
- constant tiredness and not feeling well
- loss of appetite
- weight loss
- pain in the chest
- shortness of breath
- hoarseness
- trouble swallowing
- recurrent bronchitis or pneumonia
Causes Abnormal cells associated with lung cancer reproduce rapidly and never grow into normal lung tissue. Tumors then form and interfere with the proper action of the lung or lungs. The following are among the contributing causes: - Tobacco use. According to the Canadian Cancer Society smoking "is the cause of 90% of lung cancer in men and 80% of lung cancer in women." The more cigarettes you smoke and the earlier you started smoking dramatically increase your chances of getting lung cancer. In fact a smoker is 22 times more likely to develop lung cancer than a non-smoker.
- Exposure to second hand smoke
- Exposure to environmental pollutants: asbestos arsenic uranium ore
nickel chromates bischloromethyl ether air pollution - Exposure to radon and radiation
Diagnosis Medical history smoking history exposure to environmental and occupational substances and family history of cancer are all evaluated. There will be a complete physical exam including a chest x-ray and a sputum analysis-
where coughed up phlegm is tested for signs of cancer. To confirm the presence of lung cancer the doctor must examine tissue from the lung. A bronchoscopy will be ordered. This is where the doctor slides a tiny camera into the nose or throat to look for tumors in the lungs. If it finds any tumors it can also take a little sample to be examined under a microscope.
A biopsy may also be needed. The doctor gives the patient a local anesthetic to make the procedure painless and then inserts a small needle into the chest. The needle then collects a tiny piece of tumor to be examined under a microscope.
If cancer has been discovered then the doctor will determine whether the cancer has spread to the lymph nodes. A test called a mediastinoscopy is performed under general anesthesia during which an incision is made in the throat. A tube is then inserted into the throat to collect fluid samples and biopsies from the lymph nodes near the lungs and throat.
A cat scan will likely be needed as well. A cat scan can take detailed x-rays of the lungs. It's a painless procedure where the patient lies very still inside a long tube as x-rays are taken. A second cat scan is sometimes needed - this one involving the injection of dye into a vein in order to highlight the lungs so that they can be better seen.
Treatment
Cancers that begins in the lungs are divided into two major types non-small cell lung cancer and small cell lung cancer depending on how the cells look under a microscope. Each type of lung cancer grows and spreads in different ways and is treated differently.
Many different treatments and combinations of treatments may be used to control lung cancer and/or to improve quality of life by reducing symptoms.
Surgery. The type of surgery a performed depends on the location of the tumor in the lung. An operation to remove only a small part of the lung is called a segmental or wedge resection. When the surgeon removes an entire lobe of the lung the procedure is called a lobectomy. Pneumonectomy is the removal of an entire lung. Some tumors cannot be removed by surgery because of the size or location and some patients cannot have surgery for other medical reasons.
Chemotherapy is the use of anti-cancer drugs to kill cancer cells throughout the body. Even after cancer has been removed from the lung cancer cells may still be present in nearby tissue or elsewhere in the body. Chemotherapy may be used to control cancer growth or to relieve symptoms. Most anti-cancer drugs are given by injection directly into a vein (IV) or by means of a catheter a thin tube that is placed into a large vein and remains there as long as it is needed. Some anti-cancer drugs are also given in the form of a pill.
Radiation therapy involves the use of high-energy rays to kill cancer cells. Radiation therapy targets a limited area and affects the cancer cells only in that area. Radiation therapy may be used before surgery to shrink a tumor or after surgery to destroy any cancer cells that remain in the treated area. Doctors also use radiation therapy often combined with chemotherapy as primary treatment instead of surgery. Radiation therapy may also be used to relieve symptoms such as shortness of breath. Radiation for the treatment of lung cancer most often comes from a machine (external radiation). The radiation can also come from an implant (a small container of radioactive material) placed directly into or near the tumor (internal radiation).
Treating Small Cell Lung Cancer
Small cell lung cancer spreads quickly. In many cases cancer cells have already spread to other parts of the body when the disease is diagnosed. In order to reach cancer cells throughout the body doctors almost always use chemotherapy. Treatment may also include radiation therapy aimed at the tumor in the lung or tumors in other parts of the body (such as in the brain). Some patients have radiation therapy to the brain even though no cancer is found there. This treatment called prophylactic cranial irradiation (PCI) is given to prevent tumors from forming in the brain. Surgery is part of the treatment plan for a small number of patients with small cell lung cancer.
Treating Non-small Cell Lung Cancer Patients with non-small cell lung cancer may be treated in several ways. The choice of treatment depends mainly on the size location and extent of the tumor. Surgery is the most common way to treat this type of lung cancer. Cryosurgery a treatment that freezes and destroys cancer tissue may be used to control symptoms in the later stages of non-small cell lung cancer. Radiation therapy and chemotherapy may also be used to slow the progress of the disease and to manage symptoms. Living with lung cancer Living with a serious disease is challenging. People with cancer face many fears and worries in addition to the physical challenges of their condition. Most feel overwhelmed when they are told they have lung cancer. People experience many different emotions and feelings and not everyone reacts in the same way. People with cancer their family and friends may feel shock denial fear (especially about dying and pain) anger and guilt. Dealing with such a range of feelings is often challenging. It's important not to bottle up your feelings. Talk about how you're feeling with your family friends doctor or therapist. If you or someone you know has cancer there are many support groups to help you during your treatment and recovery. You can find information and support from your health care team (doctors nurses pharmacists social workers and occupational therapists) family and friends as well as from support groups and networks. The Canadian Cancer Society offers a toll-free number where people can ask questions about cancer and get support: 1 888 939-3333. Prevention Lung cancer can often be associated with known risk factors for the disease. Many risk factors can be changed but not all can be avoided. Tobacco: Studies show that smoking tobacco products in any form is the major cause of lung cancer. People who stop smoking and never start again lower their risk of developing lung cancer or of having lung cancer recur (come back). Many products such as nicotine gum sprays inhalers patches and lozenges as well Zyban and some other antidepressant drugs may be helpful to people trying to quit smoking. Never smoking lowers the risk of dying from lung cancer. Second-hand tobacco smoke also causes lung cancer. This is smoke that comes from a burning cigarette or other tobacco product or smoke that is exhaled by smokers. People who inhale second-hand smoke are exposed to the same cancer-causing agents as smokers although in weaker amounts. Inhaling second-hand smoke is called involuntary or passive smoking. Environmental Causes: There are other causes of lung cancer in the environment but their effect on lung cancer rates is small compared to the effect of cigarette smoking. Cancer-causing agents that may be found indoors especially in the workplace include asbestos radon arsenic chromium nickel tar and soot. These substances can cause lung cancer in people who have never smoked and combine with cigarette smoke to further increase lung cancer risk in smokers. Many countries are working to control these cancer-causing agents in the workplace. Air pollution may also increase the risk of lung cancer. Studies show that lung cancer rates are higher in cities with higher levels of air pollution. Diet and Physical Activity: Studies show that a diet rich in fruit and possibly vegetables may help lower the risk of lung cancer while heavy alcohol drinking may increase the risk of lung cancer. In addition studies show that people who are physically active may have a lower risk of lung cancer than those who are not even after taking cigarette smoking into account. | 