Lung Cancer: Causes, Stages, Life Expectancy, and More
Table of Contents:
Part 1 of 13
Are there different types of lung cancer?
Lung cancer is cancer that starts in the lungs.
The most common type is non-small cell lung cancer (NSCLC). NSCLC makes up about 80 to 85 percent of all cases. Thirty percent of these start in the cells that form the lining of the body’s cavities and surfaces. This type usually forms in the outer part of the lungs (adenocarcinomas). Another 30 percent begins in cells that line the passages of the respiratory tract (squamous cell carcinoma).
A rare subset of adenocarcinoma begins in the tiny air sacs in the lungs (alveoli). It’s called adenocarcinoma in situ (AIS). This type isn’t aggressive and may not invade surrounding tissue or need immediate treatment. Faster-growing types of NSCLC include large-cell carcinoma and large-cell neuroendocrine tumors.
Small-cell lung cancer (SCLC) represents about 15 to 20 percent of lung cancers. SCLC grows and spreads faster than NSCLC. This also makes it more likely to respond to chemotherapy, but it’s also less likely to be cured with treatment.
In some cases, lung cancer tumors contain both NSCLC and SCLC cells.
Mesothelioma is another type of lung cancer. It’s usually associated with asbestos exposure. Carcinoid tumors start in hormone producing (neuroendocrine) cells.
Tumors in the lungs can grow quite large before you notice symptoms. Early symptoms mimic a cold or other common conditions, so most people don’t seek medical attention right away. That’s one reason why lung cancer isn’t usually diagnosed in an early stage.
Learn how lung cancer type can affect survival rates »
Part 2 of 13
Stages of lung cancer
Cancer stages tell how far the cancer has spread and help guide treatment. The chance of successful or curative treatment is much higher when lung cancer is diagnosed and treated in the early stages, before it spreads. Because lung cancer doesn’t cause obvious symptoms in the earlier stages, diagnosis often comes after it has spread.
Non-small cell lung cancer has four main stages:
- Stage 1: Cancer is found in the lung, but it has not spread outside the lung.
- Stage 2: Cancer is found in the lung and nearby lymph nodes.
- Stage 3: Cancer is in the lung and lymph nodes in the middle of the chest.
- Stage 3A: Cancer is found in lymph nodes, but only on the same side of the chest where cancer first started growing.
- Stage 3B: Cancer has spread to lymph nodes on the opposite side of the chest or to lymph nodes above the collarbone.
- Stage 4: Cancer has spread to both lungs, into the area around the lungs, or to distant organs.
Small-cell lung cancer (SCLC) has two main stages. In the limited stage, cancer is found in only one lung or nearby lymph nodes on the same side of the chest.
The extensive stage means cancer has spread:
- throughout one lung
- to the opposite lung
- to lymph nodes on the opposite side
- to fluid around the lung
- to bone marrow
- to distant organs
At the time of diagnosis, 2 out of 3 people with SCLC are already in the extensive stage.
Part 3 of 13
What are the symptoms of lung cancer?
Symptoms of non-small cell lung cancer and small cell lung cancer are basically the same.
Early symptoms may include:
- lingering or worsening cough
- coughing up phlegm or blood
- chest pain that worsens when you breathe deeply, laugh, or cough
- shortness of breath
- weakness and fatigue
- loss of appetite and weight loss
You might also have recurrent respiratory infections such as pneumonia or bronchitis.
As cancer spreads, additional symptoms depend on where new tumors form. For example, if in the:
- lymph nodes: lumps, particularly in the neck or collarbone
- bones: bone pain, particularly in the back, ribs, or hips
- brain or spine: headache, dizziness, balance issues, or numbness in arms or legs
- liver: yellowing of skin and eyes (jaundice)
Tumors at the top of the lungs can affect facial nerves, leading to drooping of one eyelid, small pupil, or lack of perspiration on one side of the face. Together, these symptoms are called Horner syndrome. It can also cause shoulder pain.
Tumors can press on the large vein that transports blood between the head, arms, and heart. This can cause swelling of the face, neck, upper chest, and arms.
Lung cancer sometimes creates a substance similar to hormones, causing a wide variety of symptoms called paraneoplastic syndrome, which include:
- muscle weakness
- fluid retention
- high blood pressure
- high blood sugar
Learn more about the symptoms of lung cancer »
Part 4 of 13
Lung cancer and back pain
Back pain is fairly common in the general population. It’s possible to have lung cancer and unrelated back pain. Most people with back pain don’t have lung cancer.
Not everyone with lung cancer gets back pain, but many do. For some people, back pain turns out to be one of the first symptoms of lung cancer.
Back pain can be due to the pressure of large tumors growing in the lungs. It can also mean that cancer has spread to your spine or ribs. As it grows, a cancerous tumor can cause compression of the spinal cord.
That can lead to neurologic deterioration causing:
- weakness of the arms and legs
- numbness or loss of sensation in the legs and feet
- urinary and bowel incontinence
- interference with the spinal blood supply
Without treatment, back pain caused by cancer will continue to worsen. Back pain may improve if treatment such as surgery, radiation, or chemotherapy can successfully remove or shrink the tumor.
In addition, your doctor can use corticosteroids or prescribe pain relievers such as acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs). For more severe pain, opioids such as morphine or oxycodone may be needed.
Part 5 of 13
What causes lung cancer?
Anyone can get lung cancer, but 90 percent of lung cancer cases are the result of smoking.
From the moment you inhale smoke into your lungs, it starts damaging your lung tissue. The lungs can repair the damage, but continued exposure to smoke makes it increasingly difficult for the lungs to keep up the repair. Once cells are damaged, they begin to behave abnormally, increasing the likelihood of developing lung cancer. Small-cell lung cancer is almost always associated with heavy smoking. When you stop smoking, you lower your risk of lung cancer over time.
Exposure to radon, a naturally existing radioactive gas, is the second leading cause, according to the American Lung Association.
Radon enters buildings through small cracks in the foundation. Smokers who are also exposed to radon have a very high risk of lung cancer.
Breathing in other hazardous substances, especially over a long period of time, can also cause lung cancer. A type of lung cancer called mesothelioma is almost always caused by exposure to asbestos.
Other substances that can cause lung cancer are:
- some petroleum products
Inherited genetic mutations may make you more likely to develop lung cancer, especially if you smoke or are exposed to other carcinogens.
Sometimes, there’s no obvious cause for lung cancer.
Learn more about what causes lung cancer »
Part 6 of 13
Risk factors for lung cancer
The biggest risk factor for lung cancer is smoking. That includes cigarettes, cigars, and pipes. Tobacco products contain thousands of toxic substances. According to the Centers for Disease Control and Prevention (CDC), cigarette smokers are 15 to 30 times more likely to get lung cancer than nonsmokers. The longer you smoke, the greater the risk. Quitting smoking can lower that risk.
Breathing in secondhand smoke is also a major risk factor. Every year in the United States, about 7,300 people who have never smoked die from lung cancer caused by secondhand smoke.
Exposure to radon, a naturally occurring gas, increases your risk of lung cancer. Radon rises from the ground, entering buildings through small cracks. It’s the leading cause of lung cancer in nonsmokers. A simple home test can tell you if the level of radon in your home is hazardous.
Your risk of developing lung cancer is higher if you’re exposed to toxic substances such as asbestos or diesel exhaust in the workplace.
Other risk factors include:
- family history of lung cancer
- personal history of lung cancer, especially if you’re a smoker
- previous radiation therapy to the chest
Learn more about the risk factors for lung cancer »
Part 7 of 13
Lung cancer and smoking
Not all smokers get lung cancer, and not everyone who has lung cancer is a smoker. But there’s no doubt that smoking is the biggest risk factor, causing 9 out of 10 lung cancers.
In addition to cigarettes, cigar, and pipe smoking are also linked to lung cancer. The more you smoke and the longer you smoke, the bigger your risk of lung cancer.
You don’t have to be a smoker to be affected. Breathing in other people’s smoke increases the risk of lung cancer. According to the Centers for Disease Control and Prevention CDC), secondhand smoke is responsible for about 7,300 lung cancer deaths each year in the United States.
Tobacco products contain more than 7,000 chemicals, and at least 70 are known to cause cancer.
When you inhale tobacco smoke, this mixture of chemicals is delivered directly to your lungs, where it immediately starts causing damage. The lungs can usually repair damage at first, but the continued assault on lung tissue becomes harder to manage. That’s when damaged cells can mutate and grow out of control.
The chemicals you inhale also enter your bloodstream and are carried throughout your body, increasing the risk of other types of cancer.
Former smokers are still at risk of developing lung cancer, but quitting can lower that risk considerably. Within 10 years of quitting, the risk of dying from lung cancer drops by half.
Learn more about the other causes of lung cancer »
Part 8 of 13
Diagnosing lung cancer
After a physical examination, your doctor will tell you how to prepare for specific tests, such as:
- Imaging tests: An abnormal
mass can be seen on X-ray. MRI, CT, and PET scans. These scans
produce more detail and find smaller lesions.
- Sputum cytology: If you produce phlegm when you cough, microscopic examination can determine if cancer cells are present.
A biopsy can determine if tumor cells are cancerous. A tissue sample can be obtained by:
- Bronchoscopy: While under sedation, a lighted tube is passed down your throat and into your lungs, allowing closer examination.
- Mediastinoscopy: The doctor makes an incision at the base of the neck. A lighted instrument is inserted and surgical tools are used to take samples from lymph nodes. It’s usually performed in a hospital under general anesthesia.
- Needle: Using imaging tests as a guide, a needle is inserted through the chest wall and into the suspicious lung tissue. Needle biopsy can also be used to test lymph nodes.
Tissue samples are sent to a pathologist for analysis. If the result is positive for cancer, further testing, such as a bone scan, can help determine if cancer has spread and to help with staging.
For this test, you’ll be injected with a radioactive chemical. Abnormal areas of bone will then be highlighted on the images. MRI, CT, and PET scan are also used for staging.
Learn more about how lung cancer is diagnosed »
Part 9 of 13
Treatment for lung cancer
It’s usually a good idea to seek a second opinion before beginning treatment. Your doctor may be able to help make that happen. If you’re diagnosed with lung cancer, your care will likely be managed by a team of doctors who may include:
- a surgeon who specializes in the chest and lungs (thoracic surgeon)
- a lung specialist (pulmonologist)
- a medical oncologist
- a radiation oncologist
Discuss all your treatment options before making a decision. Your doctors will coordinate care and keep each other informed.
Treatment for non-small cell lung cancer (NSCLC) varies from person to person. Much depends on specific details of your health.
Stage 1 NSCLC: Surgery to remove a portion of the lung may be all you need. Chemotherapy may also be recommended, especially if you’re at high risk of recurrence.
Stage 2 NSCLC: You may need surgery to remove part or all of your lung. Chemotherapy is usually recommended.
Stage 3 NSCLC: You may require a combination of chemotherapy, surgery, and radiation treatment.
Stage 4 NSCLC is particularly hard to cure. Options include surgery, radiation, chemotherapy, targeted therapy, and immunotherapy.
Options for small cell-lung cancer (NSCLC) also include surgery, chemotherapy, and radiation therapy. In most cases, the cancer will be too advanced for surgery.
Clinical trials provide access to promising new treatments. Ask your doctor if you’re eligible for a clinical trial.
Some people with advanced lung cancer choose not to continue with treatment. You can still choose palliative care treatments, which are focused on treating the symptoms of cancer rather than the cancer itself.
Learn more about alternative treatments for lung cancer »
Part 10 of 13
Home remedies for lung cancer symptoms
Home remedies and homeopathic remedies won’t cure cancer. But certain home remedies may help relieve some of the symptoms associated with lung cancer and side effects of treatment.
Ask your doctor if you should take dietary supplements and if so, which ones. Some herbs, plant extracts, and other home remedies can interfere with treatment and endanger your health. Be sure to discuss all complementary therapies with your doctor to make sure they’re safe for you.
Options may include:
- Massage: With a qualified therapist, massage can help relieve pain and anxiety. Some massage therapists are trained to work with people with cancer.
- Acupuncture: When performed by a trained practitioner, acupuncture may help ease pain, nausea, and vomiting. But it’s not safe if you have low blood counts or take blood thinners.
- Meditation: Relaxation and reflection can reduce stress and improve overall quality of life in cancer patients.
- Hypnosis: Helps you relax and may help with nausea, pain, and anxiety.
- Yoga: Combining breathing techniques, meditation, and stretching, yoga can help you feel better overall and improve sleep.
Some people with cancer turn to cannabis oil. It can be infused into cooking oil to squirt in your mouth or mix with food. Or the vapors can be inhaled. This may relieve nausea and vomiting and improve appetite. Human studies are lacking and laws for use of cannabis oil vary from state to state.
Part 11 of 13
Diet recommendations for people with lung cancer
There’s no diet specifically for lung cancer. It is important to get all the nutrients your body needs. If you’re deficient in certain vitamins or minerals, your doctor can advise you which foods can provide them. Otherwise, you’ll need a dietary supplement. But don’t take supplements without talking to your doctor because some can interfere with treatment.
Here are a few dietary tips:
- Eat whenever you have an appetite.
- If you don’t have a major appetite, try eating smaller meals throughout the day.
- If you need to gain weight, supplement with low sugar, high-calorie foods and drinks.
- Use mint and ginger teas to soothe your digestive system.
- If your stomach is easily upset or you have mouth sores, avoid spices and stick to bland food.
- If constipation is a problem, add more high-fiber foods.
As you progress through treatment, your tolerance to certain foods may change. So can your side effects and nutritional needs. It’s worth discussing nutrition with your doctor often. You can also ask for a referral to a nutritionist or dietician.
There’s no diet known to cure cancer, but a well-balanced diet can help you fight side effects and feel better.
Here’s how to meet your dietary needs if you have lung cancer »
Part 12 of 13
Lung cancer and life expectancy
Once cancer enters the lymph nodes and bloodstream, it can spread anywhere in the body. The outlook is better when treatment begins before cancer spreads outside the lungs.
Other factors include age, overall health, and how well you respond to treatment. Because early symptoms can be easily overlooked, lung cancer is usually diagnosed in later stages.
Survival rates and other statistics provide a broad picture of what to expect. There are significant individual differences, though. Your doctor is in the best position to discuss your outlook.
Current survival statistics don’t tell the whole story. In recent years, new treatments have been approved for stage 4 non-small cell lung cancer (NSCLC). Some people are surviving much longer than previously seen with traditional treatments.
The following are the estimated five-year survival rates for NSCLC by stage:
- Stage 1: 45 to 49 percent
- Stage 2: 30 to 31 percent
- Stage 3A: 14 percent
- Stage 3B: 5 percent
- Stage 4: 1 percent
Small-cell lung cancer (SCLC) is very aggressive. For limited stage SCLC, the five-year survival rate is 14 percent. Median survival is 16 to 24 months. Median survival for extensive stage SCLC is six to 12 months.
Long-term disease-free survival is rare. Without treatment, median survival from diagnosis of SCLC is only two to four months.
The relative five-year survival rate for mesothelioma, a type of cancer caused by asbestos exposure, is 5 to 10 percent.
Learn more about the prognosis for non-small cell lung cancer »
Part 13 of 13
Facts and statistics about lung cancer
Lung cancer is the most common cancer all around the world. According to the American Lung Association, there were 1.8 million new cases in 2012, as well as 1.6 million deaths from lung cancer.
The most common type is non-small cell lung cancer (NSCLC), accounting for 80 to 85 percent of all cases, according to the Lung Cancer Alliance. Small-cell lung cancer (SCLC) represents about 15 to 20 percent of lung cancers. At the time of diagnosis, two out of three people with SCLC are already in the extensive stage.
Anyone can get lung cancer, but smoking or exposure to secondhand smoke is linked to about 90 percent of lung cancer cases. According to the Centers for Disease Control and Prevention (CDC), cigarette smokers are 15 to 30 times more likely to get lung cancer than nonsmokers.
In the United States, each year about 7,300 people who never smoked die from lung cancer caused by secondhand smoke.
Former smokers are still at risk of developing lung cancer, but quitting can significantly lower that risk. Within 10 years of quitting, the risk of dying from lung cancer drops by half.
Tobacco products contain more than 7,000 chemicals. At least 70 are known carcinogens.
According to the US Environmental Protection Agency (EPA), radon is responsible for about 21,000 lung cancer deaths every year in the United States. About 2,900 of these deaths occur among people who have never smoked.
Black people are at higher risk of developing and dying from lung cancer than other racial and ethnic groups.
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