Cancer is a condition caused by uncontrolled growth of the cells in the body. Lung cancer, or lung carcinoma, is cancer that begins in the lungs and may spread to lymph nodes or other organs in the body, such as bones, brain and liver . It is the leading cause of cancer deaths in the United States, and smokers have the greatest risk. Some lung cancers are not related to smoking but to exposure to things like asbestos, radon, while others occur for unknown reasons. Lung cancers are grouped into two major types: non-small cell lung cancer and small cell lung cancers.
Lung cancers are usually diagnosed with chest imaging, such as chest X-ray (CXR) or computerized tomography (CT) scan. Imaging of the whole body (with PET scan) including the brain (brain MRI) are utilized to understand the degree of cancer spread.
Lung cancer diagnosis is eventually confirmed with biopsy (sample obtained from the tumor).
Treatment
Several treatment modalities are available to treat lung cancer. Type and sequence of these treatments depend on several factors, the most important one being the stage of the cancer, i.e., degree of the cancer spread.
Chemotherapy
Chemotherapy is a medication or combination of medications used to treat cancer. Chemotherapy can be given orally (as a pill) or injected intravenously (IV). When chemotherapy drugs enter the bloodstream, it destroys cancer cells. Chemotherapy is particularly useful for cancers that have metastasized, or spread. Chemotherapy attacks all quickly-dividing cells, regardless of whether they are cancerous which can cause a number of side effects, including hair loss, mouth sores, loss of appetite, nausea and vomiting, diarrhea, and low blood counts. Low blood counts can increase a patient’s risk of infection, bruising or bleeding, fatigue, and shortness of breath. The side effects of chemotherapy are generally temporary and often go away once treatment is completed. Chemotherapy regimens vary from patient to patient. They are generally repeated several times in cycles, with three to four weeks separating each cycle to allow damaged normal cells time to recover. After the first two or three sessions of chemotherapy, patients may have a CT or PET scan to see if the drug(s) is effective. If the drug(s) is not working, it may be switched out for a new drug(s).
Radiation Therapy
Radiation uses special equipment to deliver high-energy particles, such as x-rays, gamma rays, electron beams or protons, to kill or damage cancer cells. Radiation (also called radiotherapy, irradiation, or x-ray therapy) can be delivered internally through seed implantation or externally using linear accelerators (called external beam radiotherapy, or EBRT). Radiation may be used as a solitary treatment to cure the tumor or in combination with surgery and/or chemotherapy. The equipment used to deliver the radiation therapy is called a linear accelerator. The linear accelerator has a moveable arm, which enables the radiation to be focused on the part of your body where the cancer is located. Developments in EBRT equipment have enabled physicians to offer conformal radiation. With conformal radiation, computer software uses imaging scans to map the cancer three-dimensionally. The radiation beams are then shaped to conform, or match, the shape of the tumor.
Radiation works by breaking a portion of the DNA of a cancer cell, which prevents it from dividing and growing. Radiation therapy can be systemic, meaning it moves throughout your bloodstream. Systemic therapies are usually given as an injection into a blood vessel or are taken as a pill. Systemic treatments expose your entire body to cancer-fighting medication. Radiation therapy is typically given as a "local" treatment however, meaning it affects only the part of the body that needs therapy.
Tumor Resection
The surgeon removes (resects) some or all of a tumor.
Targeted Therapy & Personalized Medicine
Some lung cancers arise due to a specific change (mutation) in the lung cancer cells. In many instances there are specific drugs that target the change in the cancer, stopping the growth of the cancer, or slowing down the cancer spread. These medications are called targeted therapies and they are usually both more effective and better tolerated than chemotherapy.
Immunotherapy
Immunotherapy is a relatively recent treatment that activates immune system against cancer. It is used in many cancers, including lung cancer. Immunotherapy is sometimes given as the only cancer treatment but in some instances it is combined with chemotherapy.