All About Non-Small Cell Lung Cancer

Christine Hill-Kayser, MD, Charles B. Simone III, MD & Carolyn Vachani, RN, MSN, AOCN
OncoLink
Last Modified: December 18, 2013

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What are the lungs?

The lungs are two spongy organs found in the chest. They are responsible for delivering oxygen to the bloodstream. When you take a breath in, air moves into the lungs causing them to expand. The air can then come very close to blood that is traveling in small vessels called capillaries. When you breathe out, you exhale substances that you don't need, like carbon dioxide. The lungs are specially designed to place blood in close contact with as much air as possible, so their tissues are very delicate. The right lung has three sections, which are called lobes; the left lung has two lobes. Air comes in through your mouth and nose and then travels down a tube, called the trachea, to the lungs. The trachea divides into smaller branches called bronchi, and the bronchi keep dividing and dividing like branches on a tree. As the branches get smaller, they are called bronchioles. At the end of the branches, there are little sacs of air called alveoli. The air comes into contact with blood in the alveoli. The lungs are exposed to whatever you breathe in, so any toxic chemicals or pollutants in the air you breathe can get into your body through your lungs.

What is lung cancer?

Lung cancer happens when cells in the lung begin to grow out of control and can then invade nearby tissues or spread throughout the body. Large collections of cancer cells are called tumors. Cells in any of the tissues in the lung can develop cancer; but most commonly, lung cancer comes from the lining of the bronchi. Lung cancer is not really thought of as a single disease, but rather a collection of several diseases that are characterized by the cell type that makes them up, how they behave, and how they are treated. Lung cancer is divided into two main categories:

  • Small cell lung cancer (SCLC) - the rarer of the two types (about 15% of all lung cancers), small cell lung cancer is more aggressive than non-small cell lung cancer because it grows more quickly and is more likely to spread to other organs.
  • Non-small cell lung cancer (NSCLC) - the more common of the two types (85% of all lung cancers), non-small cell lung cancer is generally slower growing than small cell lung cancer and is divided into different types based on how the cells look that make it up - adenocarcinoma, squamous cell carcinoma, and poorly differentiated or large cell carcinoma.

This article will introduce both types of lung cancer, but focus on non-small cell lung cancer – often called NSCLC.

Am I at risk for lung cancer?

Lung cancer is the most common cause of cancer death worldwide for both men and women, with an estimated 1.6 million new cases and 1.4 million deaths annually. In the United States alone, it is estimated that 228,190 people will be diagnosed and 159,480 people will die from lung cancer in 2013. In comparison, 120,580 people are expected to die from colon, breast and prostate cancer combined in 2013 (the 2nd, 3rd, and 4th most common cancers in the U.S.).

In the US, the number of women getting lung cancer rose dramatically in the 1980s; this was attributed to the increase in women smoking some 30+ years earlier. Lung cancer due to smoking has about a 20-year latency period- that is the time from when the person starts smoking until a cancer develops. In the 1990s, lung cancer overtook breast cancer as the most common cause of cancer death among women. Almost twice as many women are expected to die from lung cancer as compared to breast cancer in the US. The good news is these rates have been declining since the early 2000s, reflecting the decline in tobacco use and has been seen in the US and Europe.

Smoking and Lung Cancer Risk

While there are a few potential causes of lung cancer, by far the most common is smoking tobacco. Every smoker (current or former) is at risk for lung cancer. It is estimated that 80-90% of all cases of lung cancer are caused by cigarette smoking. Your risk of getting lung cancer from cigarette smoking increases the longer you smoke, the more you smoke, and the deeper you inhale. Smoking low tar cigarettes does not prevent you from getting lung cancer. Importantly, if you quit smoking, your risk of getting lung cancer declines. The longer you go without smoking, the greater your risk declines. It is never too late to quit because your risk declines no matter how long you have been smoking.

What if you have already been diagnosed with a lung cancer? Approximately 50% of people diagnosed with lung cancer are active smokers. Patients who have been diagnosed with lung cancer have been found to respond to treatment better and live longer if they quit smoking at the time of their diagnosis. They can have more difficulty getting through treatment, being at higher risk of side effects such as pneumonia and lung inflammation, which can result in needing to lower the chemotherapy doses a person receives, resulting in less effective therapy. In addition, having given up smoking decreases the chance of developing another lung cancer after treatment for the current cancer.

Smoking also has an affect on people around you. Second-hand smoke, or smoke inhaled when you are near someone smoking, is another risk factor for lung cancer. It is estimated that approximately 15% of cases of lung cancer in non-smokers are caused by second-hand smoke exposure in childhood and adolescence. Non-smoking spouses of smokers are 30% more likely than spouses of non-smokers to get lung cancer. Even though many people don't "inhale" them, smoking pipes and cigars is a risk factor for lung cancer as well. Even though you are not inhaling, you are breathing the air that is filled with the smoke from these products. The more pipes or cigars you smoke, the more likely you are to get lung cancer. Although it is not as well established as cigarette smoking, smoking marijuana is also a risk factor for getting lung cancer. Both the magnitude and duration of marijuana use seems to be related to your overall risk.

Radon

Radon is the second leading cause of lung cancer in the United States. Radon is a naturally occurring odorless, colorless radioactive gas that results from the decay of rock and soil components. Radon moves up from the ground into homes, where it becomes trapped and accumulates, exposing the inhabitants to its cancer-causing potential. Different areas of the world have different amounts of radon produced, but the type of foundation in your home is also important, since some foundations are better ventilated. Because of this, two homes next door to each other could have different levels of radon in the indoor air.

Radon can accumulate in new and old homes and those with OR without a basement. The only way to know if your home contains radon is to have it tested, which can be done using a kit from a hardware store or having a radon professional perform the test. Many areas have laws requiring radon testing before a house is sold. If radon is detected in levels above 4 pCi/L (picocuries per liter), you can have a removal system installed, which vents the gas to the outside using a pipe and fan system. Because it is not clear what level of radon is safe, the EPA recommends that people consider a removal system for levels from 2-4 pCi/L.

Radiation Exposure

Radiation therapy for a prior cancer that includes lung tissue in the treatment field increases the risk for developing a new cancer in that area of the lung. Such secondary cancers often take a decade or longer to develop. This can be seen in people treated for Hodgkin lymphoma and breast cancer, among others. Some guidelines suggest that Hodgkin lymphoma survivors have screening for lung cancers after treatment. Modern radiation equipment and planning reduce the exposure of healthy tissue and may reduce this risk.

Other Risk Factors

Although smoking cigarettes is by far the most common and important risk factor for getting lung cancer, there are some environmental exposures that increase your risk for lung cancer as well. People who work with asbestos are more likely to get lung cancer; and if they smoke cigarettes too, their risk rises even higher. Asbestos is found in industries like shipbuilding, insulation/fireproofing, and asbestos mining and production. Other workers who may have a higher risk of lung cancer are those exposed to arsenic, chromium, nickel, vinyl chloride, hard metal dusts, talc, uranium, and gasoline and diesel exhaust fumes.

People who have already had lung cancer are at risk for getting it again. A history of interstitial lung disease, pulmonary fibrosis or tuberculosis (TB) also increases your risk of getting lung cancer. However, it should be stressed that cigarette smoking is far and away the most important and dangerous risk factor for developing lung cancer.

Lung Cancer in Never Smokers

The number of cases of lung cancer in never smokers (people who have smoked less than 100 cigarettes in their lifetime) has been increasing in many countries, including the US. Worldwide, never smokers make up 15-20% of new lung cancer cases in men, but 50% of new cases in women. Primarily, these are non-small cell lung cancers, as small cell lung cancer occurs almost exclusively in current or former smokers. Even more perplexing is how these rates vary based on geographic area – in Asia, 60-80% of women diagnosed with lung cancer are never smokers. This makes researchers think that lung cancer in never smokers may be a biologically different disease than in smokers.

The cause of these cancers is not clear, though the risk factors discussed above are all possibilities. Researchers are studying how these cancers may respond differently to targeted therapies aimed at specific molecular abnormalities and how smoking status could be used in treatment planning.

How can I prevent lung cancer?

The best way to prevent lung cancer is to quit smoking, or to never start in the first place. Avoid being around people who are smoking and do not use pipes, cigars, and marijuana. Have your home tested for radon and install a removal system if needed. If you work in an industry where you are exposed to substances known to cause lung cancer, make sure to use all the proper protective equipment and attire made available by your employer.

There has been some suggestion that a diet high in fruits and vegetables may decrease your risk of lung cancer. This has yet to be definitively proven. Many substances, including antioxidants like vitamin A, vitamin E, and beta-carotene, have been suggested to decrease your risk of lung cancer. None of these has been shown to be beneficial in randomized controlled trials and are not recommended for this purpose. In fact, large clinical trials have shown an increased risk of lung cancer among smokers that take high doses of vitamin E, vitamin A, and beta-carotene in the form of supplements.

The future of lung cancer prevention will rely on sophisticated analysis of patients' genes and molecular markers for lung cancer risk; this coupled with "smart drug" design and novel imaging techniques may one day help decrease the risk of developing lung cancer. Though a tremendous first step would be to get to a world of non-smokers.

What screening tests are available?

Many studies were done comparing people who were screened with chest x-rays andor sputum samples, but they never found a decrease in deaths from lung cancer as a result of this screening. However, this issue was hotly debated because some studies found that cancers can be picked up in earlier stages if patients are screened with chest x-rays. The problem is that picking up the cancers earlier did not translate to a decrease in deaths because of the screening.

The National Lung Screening Trial began in 2002 and was designed to compare annual chest CT scans (a low dose spiral CT) to chest x-rays to screen high-risk patients, with the goal of improving survival by detecting lung cancer earlier. The study had 53,000 participants who were between the ages of 55 and 74 and were current or former heavy smokers, which was defined as a minimum of 30 pack year history (pack years = # of packs per day x # of years smoked). The study found that CT scan found significantly more cancerous and pre-cancerous lesions than chest x-ray. In addition, this translated into a 20% reduction in the number of deaths from lung cancer. People screened with CT scans had more areas of concern detected, which means more testing that may ultimately not turn out to be cancer (called a false positive), but experts agree that the benefits of screening in this high risk population outweigh the risks. In 2013, the US Preventive Task Force recommended annual CT screening in current or former (quit in the last 15 years) heavy smokers, ages 55-79, taking into consideration their health and ability to undergo curative surgery if a cancer is found.

What are the signs of lung cancer?

Unfortunately, the early stages of lung cancer may not have any symptoms. As the tumor grows in size, it can produce a variety of symptoms including:

  • Cough (especially one that doesn't go away or gets worse in character)
  • Chest pain
  • Shortness of breath
  • Coughing up blood or bloody phlegm
  • New onset hoarseness or wheezing
  • Recurrent problems with pneumonia or bronchitis
  • Weight loss
  • Loss of appetite
  • Fatigue
  • Bone pain
  • Dizziness or double vision
  • Hoarseness of change in speech
  • Numbness or tingling in your arms or legs
  • Arm pain or weakness
  • Neck or facial swelling
  • Yellowing of the skin or whites of the eyes (jaundice)
  • Seizures

Many of these symptoms are non-specific, and could represent a variety of different conditions; however, your doctor needs to see you if you have any of these problems. Most patients (approximately 85%) who are diagnosed with lung cancer have symptoms that prompt a doctor to order tests to look for a problem. A cough is the most common presenting symptom of lung cancer; however, many long-term smokers have a chronic cough, so it is especially important for someone with a chronic cough to see their doctor if their cough changes in character or severity.

How is lung cancer diagnosed and staged?

When someone has symptoms suggestive of a lung tumor, they will typically be referred for blood work and a chest x-ray and/or CT scan (a 3-D x-ray) to better characterize the lesion. Your doctor may order sputum cytology, which means examining your phlegm for cancer cells. If a suspicious lesion is identified, you may have additional radiology testing, including a PET scan and often an MRI scan of the brain to further evaluate the lesion or evaluate other areas of the body where lung cancer typically spreads.

While all of these tests are important pieces of the puzzle, a biopsy is the only way to know for sure if you have cancer. A biopsy takes a sample of the suspicious area, which is then examined under a microscope for the presence of cancer cells. In addition, the biopsy is necessary to determine the type of lung cancer and if there are cancer cells present in the lymph nodes.

Biopsy

A biopsy may be taken of the suspicious nodule in the lung and/or from lymph nodes near the lungs. Your doctor will determine which areas should be biopsied and which biopsy method is best in your case. Biopsies are often done by a lung surgeon or a pulmonologist (a doctor specializing in lung diseases) who is trained in brochoscopy. Possible methods for obtaining a biopsy include:

  • Bronchoscopy: uses a thin, lighted tube placed down your nose or mouth and into your lung to look at the tumor and take samples of it. This can also be used to take samples of the lymph nodes. There are several brochoscopy techniques that can be used; your doctor will determine which methods are best in your case based on the location of the lesion and if lymph nodes are being sampled.
  • Needle biopsy: a needle is placed through the skin and between the ribs, into the tumor to get cells.
  • Thoracoscopy: A surgical procedure where the surgeon inserts a small camera into the chest wall to look at the suspicious area, evaluate the extent of it and take biopsies.
  • Video-assisted thoracoscopy or VATS: can be used for a biopsy or surgery in early stage lung cancer; this technique is similar to thoracoscopy but requires fewer/smaller incisions, which may result in quicker recovery.
  • Mediastinoscopy: A surgical procedure that uses a scope (camera on a tube), placed through the chest wall, to look at the suspicious area and take samples of lymph nodes to evaluate for the presence of cancer cells.
  • In some cases, tumors cells can get into the fluid around your lungs (called pleural fluid), and your doctor may want to drain off some fluid by putting a needle into the space where the fluid is (called a thoracentesis) and examine that fluid under a microscope.

Pathology

Once the tissue is removed, a doctor called a pathologist examines the specimen under a microscope. The pathologist determines if it is cancer or not; and if it is cancerous, they will characterize it by what type of tissue it arose from, what subtype of lung cancer it is, how abnormal it looks (known as the grade), and whether or not it is invading surrounding tissues. The pathologist sends a pathology report to your doctor, detailing his/her findings, which is an important piece in planning your treatment. You can request a copy of your report for your records.

There are several types of non-small cell lung cancer, and the type is reported on the pathology report. Non-small cell lung cancers make up approximately 85% of lung cancers. This is further broken down into subtypes, with the most common being:

  • Adenocarcinoma (˜40% of NSCLCs)
  • Squamous Cell Carcinoma (˜25% of NSCLCs)
  • Large Cell Carcinoma (˜10% of NSCLCs)

Molecular Testing

In the past decade, several genetic abnormalities have been identified in non-small cell lung cancers. These abnormalities can be used to determine prognosis and/or predict the response to a specific treatment. Many centers now routinely test for EGFR mutations and ALK gene rearrangements in metastatic lung cancer in never smokers. The presence of EGFR mutations is used to determine the appropriateness of using EGFR Inhibitor treatment, a type of "targeted therapy." Tumors with ALK gene rearrangements are treated with medications that target this abnormality. Talk to your team about molecular testing for your specific case. These will be discussed further in the treatment section.

Staging

In order to guide treatment and offer some insight into prognosis, lung cancer is "staged." This stage is based on the size and location of the tumor, if there are cancer cells in the lymph nodes and if there are cancer cells found in other areas of the body.

Clinical staging is done based on the size and location of the tumor on CT scans and PET scans, and if there is any evidence of spread to other organs that is picked up with radiology tests. In patients who have surgery as part of their lung cancer treatment, the final staging is done after surgery when the tumor and lymph nodes have been evaluated by the pathologist. This is called the pathologic stage. Hence, your stage could change after the surgery and pathology results are available. Your doctors will usually want to know the exact stage of your cancer before treatment is planned, because the stage of the cancer drastically affects how it is treated.

The staging system is somewhat complex (see the complete staging system at the end of this article), below is a simplified version of the staging for non-small cell lung cancer:

Non-Small Cell Lung Cancer Staging

  • Stage IA- the tumor is less than 3 cm, isn't in a main bronchus, and hasn't spread to any lymph nodes
  • Stage IB - the tumor is less than 5 cm, doesn't invade any organs, isn't too close to the carina, doesn't cause obstruction of the lung, and hasn't spread to any lymph nodes
  • Stage IIA- the tumor is less than 7 cm and isn't in a main bronchus, or it has spread to lymph nodes on the same side as the tumor
  • Stage IIB - the tumor is larger than 7 cm, or it directly invades the chest wall, diaphragm, lining of the heart, or other structures, or it is within 2 cm of the carina, or there is associated atelectasis or obstructive pneumonitis of the entire lung, or there are multiple tumor nodules in the same lobe of the lung
  • Stage IIIA - the tumor can have spread to different types of lymph nodes than Stage II (called mediastinal lymph nodes located in the center of the chest), but they are still on the same side as the tumor and it hasn't invaded any vital organs, or a tumor invading the mediastinum, heart, great vessels, trachea, esophagus, vertebral body, carina or other central critical structures, or there are multiple tumor nodules in different lobes of the same lung
  • Stage IIIB - the tumor has either invaded vital central organs and spread to lymph nodes, or it spread to lymph nodes on the other side of the mediastinum or lymph nodes near the collar bone (called scalene or supraclavicular)
  • Stage IV - the tumor has spread (metastasized) to other organs in the body outside the lungs (like the bones, brain, liver, or adrenal gland) or within the chest to the lining of the lung (called the pleura) or other lung

Stage IIIB and stage IV non-small cell lung cancers are generally considered inoperable, so it is very important to know if the cancer has spread to these more distant lymph nodes on the opposite side of the chest as the tumor or by the collar bone. Part of your workup to look for spread of the tumor (metastasis) will probably also entail CT scans of the liver and adrenal glands (located above the kidneys), a CT scan or MRI of your brain, and a PET scan. If you are having particular symptoms, then your doctor may want different or more specific exams. Often times, your doctor will order tests called PFT's (pulmonary function tests) to assess your lung capacity prior to considering surgery, radiation therapy, and some types of chemotherapy. Overall, your doctors will want to know as much about your particular tumor as possible so that they can plan the best available treatments.

What are the treatments for non-small cell lung cancer?

In general, the following treatments are used – they will be discussed in detail below.

  • "Early Stage" (stages I, II and some III): Surgery is used in patients who can tolerate the procedure. Most patients will also receive chemotherapy either before surgery (called neoadjuvant) or after surgery (called adjuvant). Radiation therapy can be given in patients who are not optimal candidates for surgery. With radiation therapy, most patients will also receive chemotherapy, either given before radiotherapy or during radiotherapy.
  • "Locally Advanced" (stages IIIA and some IIIB): Chemotherapy given before or during radiation therapy. Select patients can also be considered for surgery, almost always in combination with radiation therapy and chemotherapy.
  • "Advanced" (stage IIIB and IV): Chemotherapy is used to prolong survival and improve quality of life. Molecular testing is often used to determine the appropriateness of certain targeted therapies for treatment.

Surgery

For patients with non-small cell lung cancer, surgery is often used in cancers up to and including stage IIIA. The purpose of the surgery is to remove all of the cancer if possible. If the tumor is small and in a favorable location, or the patient has limited lung function, the surgeon may choose to remove the tumor with a small section of lung; this is called a wedge resection. Most times the surgeon will choose to remove the entire lobe of the involved lung; this is known as a lobectomy. On occasion, the surgeon must remove the entire lung affected by the cancer; and this is known a pneumonectomy.

Not every patient can tolerate these surgeries. Patients with diminished lung function may not be able to tolerate a surgery. Preoperative pulmonary function tests (PFT's) are used to help predict who is a good candidate for surgery. Sometimes a quantified ventilation perfusion scan will be ordered, which shows the amount that each area of lung is currently working. These tests may help the surgeon to predict how much lung function will be lost based on the amount of lung that will need to be removed, and how well the patient will feel after surgery.

Another potential use for surgery with lung cancer lies in treating solitary brain, spinal, or adrenal metastases. If a patient has a solitary lesion in the brain or spine, a neurosurgeon may elect to remove them surgically. Similarly a solitary lesion in the adrenal gland may be optimally managed with surgical removal. Talk with your doctor about the different ways to approach treatment of your particular disease.

Chemotherapy

Even when surgery removes all the visible tumor, there is a risk of the cancer coming back because there may be microscopic cancer cells that have traveled through the lymph or blood systems. Chemotherapy is used to travel throughout the body, destroying any cancer cells that are not able to be detected by routine testing. In the case of metastatic lung cancer (the cancer has spread outside the lung), chemotherapy is used to prolong survival and improve the patient's quality of life.

Chemotherapy is the use of anti-cancer medications that go throughout the entire body. These medications may be given through a vein or as pills by mouth. Chemotherapy can be given before surgery (called neoadjuvant therapy) or after surgery (adjuvant therapy). When chemotherapy is given with radiation therapy, they are often given at the same time (called concurrent chemoradiation). In that case, the chemotherapy not only treats the cancer, but also works as a "radiosensitizer," making the tissues more sensitive to the effects of the radiation, helping the radiation therapy work better.

There are many different chemotherapy medications, and they are often given in combinations, using two or more medications that work differently, to attack the cancer cells from different angles. Treatments are often given in your oncology provider's office, by a nurse trained in chemotherapy administration. Different chemotherapy regimens are used for different patients, based on the type of lung cancer, side effect profile of the medication and the goal of treatment. Some of the chemotherapy agents used include: etoposide, cisplatin, carboplatin, ifosfamide, cyclophosphamide, vinblastine, doxorubicin, paclitaxel, docetaxel, pemetrexed, gemcitabine and vinorelbine. There are advantages and disadvantages to each of the different regimens that your medical oncologist will discuss with you. Based on your own health, your personal values and wishes, and side effects you may wish to avoid, you can work with your doctors to come up with the best regimen for your cancer and your lifestyle.

Research is studying a variety of things that can be measured in the patient or the tumor (called biomarkers) that can be used to predict the patient's prognosis, the potential benefit (or lack thereof) of chemotherapy or how well a certain treatment will work. This is often described as "personalized medicine," where the treatment is no longer just based on the cancer type, but much more specific to the genetic make up of a patient's particular tumor. Much of this shift in treatment decisions are possible because of targeted therapies.

Targeted Therapies/Biologic Therapies

Cancers have abnormal genetic pathways and receptors, some of which have been identified by researchers and in some cases, can be detected with laboratory tests. These abnormal pathways and receptors allow cells to become cancerous and/or resistant to treatment with chemotherapy and radiation therapy. Targeted (also called "biologic") therapies are a new class of medications that have been specifically designed to target specific pathways or receptors in various cancers. These medications often produce less significant side effects than standard chemotherapy drugs and can be given alone or in combination with standard chemotherapy. One type of targeted therapy is an anti-angiogenesis agent, which targets receptors on blood vessels, inhibiting the growth of new blood vessels, in turn slowing tumor growth by cutting off its blood supply. Bevacizumab is a type of anti-angiogensis agent used in lung cancer treatment.

Some therapies are used in patients with advanced cancers (stage IV) that are found to have specific genetic abnormalities. The two abnormalities currently used to determine treatments are EGFR mutations and ALK gene rearrangement.

Mutations in the epidermal growth factor receptor (EGFR) are found in 10% of Caucasian patients with adenocarcinoma, but 50% of Asian patients with adenocarcinoma. It is more commonly found in women and non-smokers and is a good prognostic indicator- meaning having this abnormality has a better prognosis (outcome) than not having it. Its presence means that the tumor is more likely to respond to treatment with EGFR inhibitor medications (erlotinib and gefitinib, the latter of which is only available in Europe).

The EML4-ALK rearrangement is found in 2-7% of NSCLC and is more common in men, adenocarcinomas, non-smokers and younger patients. In general, ALK rearrangement and EGFR mutations do not occur together in the same patient. The presence of ALK rearrangement predicts a good response to a medication that targets this abnormality (crizotinib).

Immunotherapy is the use of an agent to stimulate the body's own immune system to target the cancer cells. Vaccine therapy is one type of immunotherapy being studied in the treatment of lung cancer after surgery.

Radiotherapy

Radiation therapy uses high-energy rays (similar to x-rays) to kill cancer cells and is commonly used to treat lung cancer. Radiation therapy is given using a machine called a linear accelerator. Treatment is typically given 5 days a week, for up to 6-8 weeks at a radiation therapy treatment center. The treatment takes just a few minutes and is painless. Radiation therapy may be recommended before surgery to shrink a tumor to make it easier for the surgeon to remove. Radiation therapy may be used after surgery if there are worrisome risk factors that make it likely for a tumor to come back in the chest. Radiation therapy can be used instead of surgery if a surgery is felt to be too dangerous for the patient, or if a tumor is too extensive to be removed with surgery.

Radiation therapy, given after or concurrently with chemotherapy, is the most commonly used treatment for locally advanced lung cancer.

Stereotactic Radiation

Stereotactic radiation, often referred to as stereotactic body radiation therapy (SBRT) or stereotactic ablative body radiotherapy (SABR), is a form of radiation therapy that very precisely delivers a high dose of radiation therapy to a tumor. SBRT differs from standard radiation therapy, in that it involves fewer treatments; typically 1-5 treatments over 1-2 weeks, compared with the 6-8 week regimens with conventional radiation therapy. Although SBRT involves fewer fractions, the radiation dose delivered during each fraction is much higher than conventional radiation therapy in order to achieve the same or even greater biological effect at killing tumor. Since the dose per day of radiation therapy is so high, the radiation oncologist must very precisely target the lesion's/tumor's location. In order to do this, SBRT functions like a magnifying glass, delivering radiation therapy from different angles to focus the irradiation at one small point where the beams converge. The use of multiple unique beam angles or arcs limits dose to the surrounding normal tissue.

SBRT to the lung is usually recommended in patients with very early stage lung cancer who cannot undergo surgery, mostly due to other medical issues. Multiple studies have demonstrated that SBRT can completely eradicate the lung tumor and prevent more than 90% of these lung cancers from coming back. Surgery is still the standard of care for early stage lung cancer, but SBRT is being increasingly used and is preferred if a patient is unable to tolerate surgery. Additional studies are underway to directly compare SBRT to surgery in early stage lung cancer.

SBRT to the lung is typically delivered with either CyberKnife or Linac-based SBRT. Location and size of tumors are very important in selecting this treatment, as tumors in the wrong location can put patients at increased risk for serious side effects. For example, if a tumor is very close to the trachea (windpipe), patients can experience damage to these areas and may not be good candidates for this treatment.

Radiation for Metastatic Disease

Radiation is often used in the setting of metastatic disease or cancer cells that have spread to other regions of the body, including the bones, spine and brain. Radiation can be used to reduce pain from metastatic disease, or reduce the risk of problems from cancer that has spread to the brain or vertebral bodies.

Photodynamic Therapy

Photodynamic therapy (PDT) is a treatment that uses light to damage malignant or abnormal tissues. PDT is FDA-approved for providing relief of obstruction caused by non-small-cell lung cancer (NSCLC) and the treatment of small lung cancers located in the trachea, in people who are not able to have surgery. PDT uses a light source, such as a laser, combined with a drug that makes the tissues light-sensitive, which is known as a "photosensitizer." When the light and photosensitizer are combined, oxygen-free radicals that are able to destroy cancer cells are released. Photosensitizers are often taken up in greater amounts by cancer cells compared to normal cells.

A photosensitizing drug is given to the patient a hours to a few days prior to the light exposure, but the drug is not activated until it is exposed to a particular wavelength of light. When the light is directed at the area of the cancer, the photosensitizer is activated and the cancer cells are destroyed. This wavelength determines how far the light can travel into the body. Typically, the depth of penetration is on the order of millimeters. Therefore, PDT is generally not used to treat large tumors, because the light cannot reach the necessary depth to treat those tumors. Different photosensitizers are activated by different wavelengths of light; therefore, depending on the area of the body to be treated, there are different photosensitizing drugs and different wavelengths of light that can be used.

Learn more about PDT.

Follow-up testing

Once a patient has been treated for lung cancer, he or she needs to be closely followed by the oncology team. At first, you will have follow-up visits fairly often. The longer you are free of disease, the less often you will have to go for checkups. Your doctor will tell you when he or she wants follow-up chest x-rays, CT scans, or other tests. It is very important that you keep all of your follow-up appointments and let your doctor know about any symptoms you are experiencing.

Finally, if you haven't yet done it, you need to quit smoking. Remember, it is never too late to get the health benefits of smoking cessation. If your family members smoke, it is a great opportunity to support each other and quit together. There are many programs to provide support in quitting and good medications to support your efforts as well. Learn more about smoking cessation on OncoLink.

Clinical trials are extremely important in furthering our knowledge and the treatment of this disease. It is though clinical trials that we know what we do today, and exciting new therapies are always being tested. Talk to your healthcare provider about participating in clinical trials in your area or search for trials using the OncoLink Clinical Trials Matching program.

Cancer survivorship is a relatively new focus of oncology care. With some 13 million cancer survivors in the US alone, there is a need to help patients transition from active treatment to survivorship. What happens next, how do you get back to normal, what should you know and do to live healthy going forward? A survivorship care plan can be a first step in educating yourself about navigating life after cancer and helping you communicate knowledgeably with your healthcare providers. Create a care plan today on OncoLink.

This article is meant to give you a better understanding of lung cancer. You may find this knowledge useful when meeting with your physician, making treatment decisions, and continuing your search for information.

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  • Marcus, P.M. (2000) Lung Cancer Screening: An Update. Journal of Clinical Oncology, 19(18S) Supplement, 83S-86S.
  • McCloskey, P., Balduyck, B., Van Schil, P. E., Faivre-Finn, C. & O'Brien, M. (2013) Radical Treatment of Non-small Cell Lung Cancer During the Last 5 Years. European Journal of Cancer 49, 1555-1564.
  • Mirsadraee, S. et al. (2012) The 7th lung cancer TNM classification and staging system: Review of the changes and implications. World J Radiol. 2012 April 28; 4(4): 128–134.
  • National Cancer Institute. What You Need To Know About Lung Cancer. www.cancer.gov.
  • Rubin, P. and Williams, J.P., (Eds): Clinical Oncology: A Multidisciplinary Approach for Physicians and Students 8th ed. (2001). W.B. Saunders Company, Philadelphia, Pennsylvania.
  • UptoDate: Lung Cancer Reviews (2013).
  • US Preventive Services Task Force: Draft Recommendation Statement (July 2013).

Complete Staging Systems:

TNM Staging for Lung Cancer (7th Edition)
The 7th edition of TNM staging became the standard in 2010 and this edition recommends using TNM for small cell and non-small cell lung cancers. However, the two stage system (limited versus extended) is still widely used for small cell lung cancer.

Primary Tumor (T)

T1: Tumor ≤3 cm diameter, surrounded by lung or visceral pleura, without invasion more proximal than lobar bronchus
T1a: Tumor ≤2 cm in diameter
T1b: Tumor >2 cm but ≤3 cm in diameter

T2: Tumor >3 cm but ≤7 cm, or tumor with any of the following features:

  • Involves main bronchus, ≥2 cm distal to carina
  • Invades visceral pleura
  • Associated with atelectasis or obstructive pneumonitis that extends to the hilar region but does not involve the entire lung

T2a: Tumor >3 cm but ≤5 cm
T2b: Tumor >5 cm but ≤7 cm

T3: Tumor >7 cm or any of the following:

  • Directly invades any of the following: chest wall, diaphragm, phrenic nerve, mediastinal pleura, parietal pericardium, main bronchus <2 cm from carina (without involvement of carina)
  • Atelectasis or obstructive pneumonitis of the entire lung
  • Separate tumor nodules in the same lobe

T4: Tumor of any size that invades the mediastinum, heart, great vessels, trachea, recurrent laryngeal nerve, esophagus, vertebral body, carina, or with separate tumor nodules in a different ipsilateral lobe

Regional Lymph Nodes (N)

N0: No regional lymph node metastases
N1: Metastasis in ipsilateral peribronchial and/or ipsilateral hilar lymph nodes and intrapulmonary nodes, including involvement by direct extension
N2: Metastasis in ipsilateral mediastinal and/or subcarinal lymph node(s)
N3: Metastasis in contralateral mediastinal, contralateral hilar, ipsilateral or contralateral scalene, or supraclavicular lymph node(s)

Distant Metastases (M)

M0: No distant metastases
M1: Distant Metastases
M1a: Separate tumor nodule(s) in a contralateral lobe; tumor with pleural nodules or malignant pleural or pericardial effusion
M1b: Distant metastasis (in extrathoracic organs)

Stage

These TNM results are compiled to come up with a stage using the chart below:

Stage Grouping

Stage IA

T1a-T1b

N0

M0

Stage IB

T2a

N0

M0

Stage IIA

T1a, T1b, T2a

N1

M0

T2b

N0

M0

Stage IIB

T2b

N1

M0

T3

N0

M0

Stage IIIA

T1a, T1b, T2a, T2b

N2

M0

T3

N1, N2

M0

T4

N0, N1

M0

Stage IIIB

T4

N2

M0

Any T

N3

M0

Stage IV

Any T

Any N

M1a of M1b



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