What is Lung Cancer?
Lung cancer is a type of cancer that begins in the lungs. Your lungs are two spongy organs in your chest that take in oxygen when you inhale and release carbon dioxide when you exhale. People who smoke have the greatest risk of lung cancer. The risk of lung cancer increases with the length of time and number of cigarettes you've smoked. If you quit smoking, even after smoking for many years, you can significantly reduce your chances of developing lung cancer.
Lung cancer is the uncontrolled growth of abnormal cells in one or both lungs. These abnormal cells do not carry out the functions of normal lung cells and do not develop into healthy lung tissue. As they grow, the abnormal cells can form tumors and interfere with the functioning of the lung, which provides oxygen to the body via the blood.
There are two major types of lung cancer, non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). Staging lung cancer is based on whether the cancer is local or has spread from the lungs to the lymph nodes or other organs. Because the lungs are large, tumors can grow in them for a long time before they are found. Even when symptoms—such as coughing and fatigue—do occur, people think they are due to other causes. For this reason, early-stage lung cancer (stages I and II) is difficult to detect. Most people with lung cancer are diagnosed at stages III and IV.
Non-small cell lung cancer accounts for about 85 percent of lung cancers. Among them are these types of tumors:
- Adenocarcinoma is the most common form of lung cancer in the United States among both men and women.
- Squamous cell carcinoma (which is also called epidermoid carcinoma) forms in the lining of the bronchial tubes.
- Large cell carcinomas refer to non-small cell lung cancers that are neither adenocarcinomas nor epidermoid cancers.
• Stage I : The cancer is located only in the lungs and has not spread to any lymph nodes.
• Stage II : The cancer is in the lung and nearby lymph nodes.
• Stage III : Cancer is found in the lung and in the lymph nodes in the middle of the chest, also described as locally advanced disease. Stage III has two subtypes:
o If the cancer has spread only to lymph nodes on the same side of the chest where the cancer started, it is called stage IIIA.
o If the cancer has spread to the lymph nodes on the opposite side of the chest, or above the collar bone, it is called stage IIIB.
• Stage IV : This is the most advanced stage of lung cancer, and is also described as advanced disease. This is when the cancer has spread to both lungs, to fluid in the area around the lungs, or to another part of the body, such as the liver or other organs.
Small cell lung cancer results from smoking even more so than non-small cell lung cancer, and grow more rapidly and spread to other parts of the body earlier than non-small cell lung cancer. It is also more responsive to chemotherapy.
• Limited stage : In this stage, cancer is found on one side of the chest, involving just one part of the lung and nearby lymph nodes.
• Extensive stage : In this stage, cancer has spread to other regions of the chest or other parts of the body.
Treatment for lung cancer can involve surgical removal of the cancer, chemotherapy, or radiation therapy, as well as combinations of these treatments. The decision about which treatments will be appropriate for a given individual must take into account the location and extent of the tumor as well as the overall health status of the patient.
As with other cancers, therapy may be prescribed that is intended to be curative (removal or eradication of a cancer) or palliative (measures that are unable to cure a cancer but can reduce pain and suffering). More than one type of therapy may be prescribed.
Surgical removal of the tumor is generally performed for limited-stage (stage I or sometimes stage II) NSCLC and is the treatment of choice for cancer that has not spread beyond the lung. About 20%-45% of lung cancers can be removed surgically, but removal does not always result in a cure, since the tumors may already have spread and can recur at a later time.
The surgical procedure chosen depends upon the size and location of the tumor. Surgeons must open the chest wall and may perform a wedge resection of the lung (removal of a portion of one lobe), a lobectomy (removal of one lobe), or a pneumonectomy (removal of an entire lung). Sometimes lymph nodes in the region of the lungs also are removed (lymphadenectomy). Surgery for lung cancer is a major surgical procedure that requires general anesthesia, hospitalization, and follow-up care for weeks to months.
Radiation therapy may be employed as a treatment for both NSCLC and SCLC. Radiation therapy uses high-energy X-rays or other types of radiation to kill dividing cancer cells. Radiation therapy may be given as curative therapy, palliative therapy (using lower doses of radiation than with curative therapy), or as adjuvant therapy in combination with surgery or chemotherapy.
Chemotherapy: This is the treatment of cancer with anti-cancer drugs. The aim is to destroy cancer cells while doing the least possible damage to normal cells. The drugs work by stopping cancer cells from multiplying.Chemotherapy is the treatment of choice for patients with small cell carcinoma. As this type of cancer spreads quickly, chemotherapy works well in treating it.
Targeted therapy drugs more specifically target cancer cells, resulting in less damage to normal cells than general chemotherapeutic agents. Erlotinib and gefitinib target a protein called the epidermal growth factor receptor (EGFR) that is important in promoting the division of cells. This protein is found at abnormally high levels on the surface of some types of cancer cells, including many cases of non-small cell lung cancer.
Traditional, or "open," surgery calls for large incisions and longer recovery times for patients. However, advances in computer imaging have paved the way for less invasive techniques. From tiny, tube-like cameras that can look inside the body to imaging machines that provide real-time views in the operating room, cancer surgeons have many tools to provide effective cancer treatment with much less impact on the patient. As these minimally invasive techniques advance, many are replacing standard surgery for a variety of cancers.
- da Vinci® Robotic Surgery
- Video assisted thoracoscopic surgery (VATS)
The minimally invasive procedure offers several advantages for eligible patients over traditional thoracotomy:
- Less postoperative pain and inflammation
- A shorter hospital stay
- Shorter duration of use of drains
- Preservation of lung function, and
- A faster return to normal activities.
A quicker recovery also benefits patients who must begin chemotherapy treatment as soon as possible after surgery. Traditional thoracotomy may be a preferred treatment for some patients with large tumors, lymph node involvement, or prior chest surgery.
You may want to ask some questions before your treatment begins: