Introduction of Lung Cancer
Lung cancer is the second most common malignancy affecting both sexes. Roughly 180,000 Americans are diagnosed with this illness ever year. It is considered the most rapidly increasing cause of death from cancer. Since 1987, lung cancer has been the leading cause of cancer death in women, surpassing breast cancer. And while lung cancer incidence has leveled off among men, it continues to rise steadily among women. The average age of patients with lung cancer is 60 years. It is more common in African-Americans and Hawaiians.
Causes
Cigarette smoking is the number one cause of this disease. Even passive inhalation of the smoke increases the chance of developing this illness. Radon exposure is another cause of lung cancer, killing 14,000 Americans every year. Asbestos exposure also increases Lung cancer risk. The risk becomes astronomical in exposed individuals who also smoke.
Signs and Symptoms
Patients do not manifest any signs in the very early stages. Cough, shortness of breath, chest pain or blood in the sputum are among the early warning signs. Other signs of this illness could be a change of voice, hoarseness, weakness, fatigue, and weight loss.
Establishing Diagnosis
When the diagnosis is suspected, patients must be examined carefully by a qualified physician. A chest x-ray along with studying a sample of sputum are the very first steps in establishing a diagnosis. If the study sputum does not confirm the diagnosis, then Bronchoscopy and biopsy are the next steps. In certain patients, cancer may have already spread to lymph glands in the neck. In such cases, a Fine needle aspiration of the lymph gland should be performed. This is a fairly easy procedure. Unfortunately, most doctors avoid the simple test of sputum study. There is no reason not to perform this test, since it establishes the diagnosis in about 30% of patients. In a small percentage of patients, none of the above tests will lead into a diagnosis and there will be a need to proceed with more invasive procedures, and perhaps surgery.
Different Types of Lung cancer
There are two basic kinds of lung cancer:
- Small cell or oat cell, that occurs in one-third of all patients with lung cancer
- Non-small cell in two-thirds of patients.
This distinction is rather important, because the treatment for the two kinds is very different. Small cell cancers are primarily treated with Chemotherapy. Surgery does not play a role in this type of lung cancer. On the other hand, Non-small cell lung cancer is treated primarily with surgery.
Another type of cancer that can develop in the lungs is Carcinoid Tumor.
Staging Work-Up
Once a diagnosis of the lung cancer is established, a thorough examination of the patient should be performed to disclose crucial information. CT scan of the chest and abdomen and a bone scan should be performed to determine the extent of cancer spread. Additional tests for Small Cell Lung Cancer include CT scan of the brain and a bone marrow test. The purpose of these tests is to study the areas where cancer has a tendency to spread.
Small cell cancers have two stages,
- Limited stage, when the cancer is confined to a defined area in the chest
- Extensive stage, when the cancer may have spread to a wider area in the chest or to areas outside the chest
Patterns of Spread
Lung cancer can either spread locally and involve nearby tissues, such as the cavity outside the lungs (pleural space), layers around the heart, or may travel to distant sites such as local lymph glands or the liver, bones, brain or the opposite lung. Other organs where lung cancer has a tendency to spread are the adrenal glands, which are the glands located above the kidneys and which produce special hormones. Another area where cancer may spread is the area near the spinal cord and vertebrae.
Treatment of Small Cell Lung Cancer
Limited stage small cell lung cancers are usually treated with a combination radiation to the chest and Chemotherapy. There is no role for surgery. There are many different ways to combine these two modalities. There is a small chance to completely cure this condition in up to five percent of patients. Age of the patients and their overall health status determine the intensity of treatment. A general rule is that younger patients are treated with more aggressive regimens. The most effective chemotherapy drugs used to treat this condition are VP-16, Carboplatinum, and Cisplatinum. If the disease does not respond to these drugs, there are other drugs that could be used. Radiation therapy may also be administered at the same time as Chemotherapy, or after completion of Chemotherapy. Chemotherapy is normally given every three to four weeks for a period of at least six months.
Extensive stage small cell lung cancer is normally treated with the same chemotherapy drugs as mentioned above. There is no rule for using radiation therapy to the chest. However, if cancer has spread to brain or bones, those areas could be treated with radiation therapy. Unfortunately, a cure is not possible for this condition. However, the illness is quite manageable for a period of time, varying form months to even years.
Recently a number of new active drugs have been identified for treating patients with small cell lung cancer. These agents include Taxol, Taxotere, Irinotecan, Topotecan and Gemcitabine.
Treatment of Non-Small Cell Cancer
Surgery is the only treatment to cure this disease in its earlier stages, when the disease is confined to a small area in the chest. About one-third of such patients could be cured by surgery. Since chest surgery is a major undertaking, it is extremely important to confirm the extent of the condition prior to surgery. Such patients need to have a full staging work-up and a Bronchoscopy, as well as a Mediastinoscopy, where the local lymph glands in the chest are sampled and studied. This procedure must be done in every patient about to undergo a radical surgery. Without surgery, a cure is not feasible. In such cases, chemotherapy should be considered, as well as radiation therapy.
The most effective chemotherapy drugs used to treat this condition are Carboplatinum, Cisplatinum, Taxol, Vinorelbine, Taxotere, Irinotecan and Gemcitabine. Most these drugs are used in patients with advanced stages of this disease and they are used in combination such as combinations of: Taxol and Carboplatinum or more recently Gemcitabine and Vinorelbine.
The response rate to these drugs are in neighborhood of 30-40% of treated patients with duration of response lasting anywhere from 6-12 months and rarely up to a few years.
Radiation therapy may be administered at the same time as Chemotherapy, or after completion of Chemotherapy. Chemotherapy is normally given every three to four weeks, for a period of at least six months.
Special Situations
Patients with advanced lung cancer may develop any of the following complications.
- Pleural effusion
- Pericardial effusion
- Superior Vena Cava obstruction
- Spinal cord compression
- Brain metastasis
- Bone metastasis
- Pancoast syndrome
- Paraneoplastic syndromes
- Low sodium level
- High calcium level
- Eaton Lambert Syndrome, which is a form of muscle weakness due to nervous system problems.
- Pain
Survival
Survival of patients with lung cancer will depend on the type and extent of the cancer at the time of initial diagnosis. One-third of patients with early stages of non-small cell lung cancer could be cured with surgery alone. This percentage is much smaller in patients with early stage small cell cancers -- less than five percent. In the majority of patients in whom cure is not possible survival may vary from months to years, depending on the extent of the cancer, the overall condition of the patient, as well as his/her response to treatment and the duration of that response.
Follow-up
After completion of treatment, in any combination that might have taken place, patients need to remain under surveillance for possibility of a recurrence of cancer. Follow-up should be scheduled on a regular basis, initially every one to three months for one to two years. The frequency of follow-up will depend on the condition of the patient and his/her disease. In each follow-up visit, patients are examined. Normally, a chest x-ray is obtained every few months and CT scan of chest and bone scan once a year.
Treatment of recurrent disease will depend on the stage and extent of the reoccurred disease. Most patients are then treated with chemotherapy with same agents as mentioned above. Radiation therapy may be helpful in managing painful or symptomatic areas to which the cancer has spread. If patients experience pain, different pain medications may be used to alleviate pain. For patients with advanced disease where most treatments have failed, one could consider assistance from Hospice.
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