Understanding Lung Cancer
Lung cancer is the second most common cancer among both men and women in the United States. More than 220,000 new cases of the disease will be diagnosed this year. Lung cancer also is the leading cause of cancer death among American men and women, and will claim more than 158,000 lives across the U.S. in 2016. Lung cancer is responsible for approximately one of every four cancer deaths, and kills more people each year than breast, prostate, and colon cancer combined.
While those numbers are daunting, recent years have been marked by several hopeful signs in the fight against lung cancer, including the development of new types of agents that have been shown to prolong survival in advanced stages of the disease by harnessing the body’s immune system.
The oncology specialists of Regional Cancer Care Associates (RCCA) are at the forefront of the battle against lung cancer, both through the cutting-edge care they provide to patients and through their work as investigators in clinical trials evaluating new treatment strategies and therapies. While you should discuss questions and concerns about lung cancer with your physician or other healthcare provider, RCCA’s specialists provide the information on this page for general educational purposes.
The most significant risk factor for lung cancer is smoking. The Centers for Disease Control and Prevention (CDC) estimates that up to 90 percent of lung cancer cases are linked to cigarette smoking. While quitting smoking will lower your risk of developing lung cancer no matter how long you may have smoked, people who have a history of smoking still have a higher risk of lung cancer than those who never smoked. Other risk factors for lung cancer include:
– Exposure to second-hand smoke
– Family history of lung cancer
– Certain genetic mutations
– Receiving radiation to the breast or chest
– Exposure to radon
Studies published in recent years have documented a modest increase in the incidence of lung cancer among people who never smoked. The cause for this reported trend is unclear, and it is the focus of ongoing research. Regardless, smoking remains the most important risk factor for lung cancer, and stopping smoking is the best step a person can take to reduce his or her risk for developing the disease.
Types of Lung Cancer
There are two main types of lung cancer. The most common type is non-small cell lung cancer, or NSCLC, which accounts for about 85 percent of cases. There are many types of non-small lung cancer, including:
– Squamous cell carcinoma, also known as epidermoid carcinoma. This cancer is responsible for approximately 25 percent of all lung cancer cases. This type of cancer begins in the flat cells that line the airways of the lung and tends to be found near a main airway.
– Large cell carcinoma. This form of cancer can develop in any area of the lung.
– Adenocarcinoma. This form of non-small cell lung cancer often begins in the alveoli that line the lungs.
The remaining ten to 15 percent of lung cancers are characterized as small cell lung cancer because of the way their cells appear under a microscope. Small cell lung cancer is sometimes referred to as oat cell cancer. Small cell lung cancer tends to spread quickly.
Signs and Symptoms
Most signs and symptoms of lung cancer are non-specific, meaning that they may be indicative of many conditions, many of which are less serious than lung cancer. If you experience one or more of the following, consult your physician or other healthcare provider promptly:
– Persistent or worsening cough
– Shortness of breath
– Chest pain
– Coughing up blood
– Feeling fatigued all the time
– Unexplained weight loss
Screening and Diagnosis
When a patient seeks medical attention for one or more of the signs and symptoms listed above, a physician typically obtains a detailed history and performs a physical examination, ordering any indicated imaging studies and laboratory tests based on the findings of the history and physical.
Lung cancer usually is diagnosed by means of a low-dose computed tomography (LDCT) scan, which is a low-dose radiation imaging study that provides the physician with a detailed view of the lungs. The U.S. Preventive Services Task Force recommends annual lung cancer screenings with LDCT for people between the ages of 55 and 80 who have a “30 pack-year” smoking history and who currently smoke or have quit within the past 15 years. A pack-year is the equivalent of smoking one pack of cigarettes per day for one year. So if a person smoked one pack of cigarettes each day for 30 years, or two packs a day for 15 years, he would have smoked for 30 “pack-years.”
Lung cancer can be treated with surgery, radiation therapy, radiofrequency ablation, chemotherapy, targeted therapy, and immunotherapy. Several different approaches often are used in combination to tailor treatment to the specific nature of a patient’s disease.
Either conventional or robotic surgery may be employed in treating lung cancer, particularly in the early stages of non-small cell lung cancers. The use of robotic surgery has increased in recent years because the precision it offers can help minimize the invasiveness of the procedure and reduce postoperative recovery time.
Radiation therapy can involve external beam radiation therapy (EBRT), in which radiation is directed to cancer cells from outside the body, or brachytherapy, in which small radioactive “seeds” are placed in the lung, usually via a bronchoscope, to kill cancer cells by emitting radiation over a small radius. There are a number of very sophisticated approaches to EBRT, including three-dimensional conformal radiation therapy (3D-CRT), which uses computers to precisely match the tumor’s location; intensity-modulated radiation therapy (IMRT), an advanced form of 3D therapy; and stereotactic body radiation therapy, which aims multiple beams of high-dose radiation at a tumor from different directions. Meanwhile, radiofrequency ablation (RFA) entails using high-energy radio waves to heat a tumor and destroy cancer cells. It typically is used in cases of small NSCLC tumors near the edge of the lungs when the patient is not a good candidate for surgery.
Different chemotherapy regimens are used to treat lung cancer. Targeted therapies, meanwhile, work to inhibit the growth of tumors. Some prevent the formation of blood vessels that provide tumors with the nourishment they need to grow, while others interfere with the action of a protein on the surface of cancer cells that facilitates cell growth and division. More recently, immunotherapy agents called checkpoint inhibitors, which prevent cancerous cells from evading detection by the body’s immune defenses, have been prescribed to prolong survival in advanced forms of lung cancer. Their effectiveness in earlier stages of the disease is being investigated.
It is important to discuss the potential benefits and side effects of each treatment with your physician. Lung cancer is the focus of intensive research and clinical trials, which means that patients and their physicians may have even more treatment options in the years immediately ahead.
The oncologists of Regional Cancer Care Associates are always available to see you or to consult with your physician if you have been diagnosed with lung cancer. In addition, reliable resources for obtaining further information include the following: