Lung Cancer: Stages, Symptoms, Causes, Risk Factors, Diagnosis, Treatment and Prognosis

Tumors in the lungs can grow quite large before you notice symptoms.

Lung cancer is cancer that begins in the lungs. The most common type is non-small cell lung cancer. It constitutes approximately 80% to 85% of all cases. 30% of these begin in the cells that form the lining of the body’s cavities and surfaces.

This type usually forms on the outside of the lungs ( adenocarcinomas ). Another 30% begins in the cells that line the breathing tubes (squamous cell carcinoma).

Small cell lung cancer accounts for about 15 to 20 percent of lung cancers. It grows and spreads faster than non-small cell lung cancer. This also makes it more likely that it will respond to chemotherapy, but it is also less likely to be cured with treatment.

Mesothelioma is another type of lung cancer. It is usually associated with exposure to asbestos. Carcinoid tumors begin in hormone-producing (neuroendocrine) cells.

The first symptoms mimic a cold or other common conditions, so most people do not seek medical attention immediately. That is one reason why lung cancer is generally not diagnosed at an early stage.

Stages of lung cancer

Cancer stages indicate how far the cancer has spread and help guide treatment.

The chance for successful or curative treatment is much higher when lung cancer is diagnosed and treated in the early stages, before it spreads.

Because lung cancer does not cause obvious symptoms in the early stages, the diagnosis often occurs after it has spread.

Non-small cell lung cancer has four main stages:

  • Stage 1: The cancer is 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: The cancer is in the lung and the lymph nodes in the middle of the chest.
  • Stage 3A : Cancer is found in the lymph nodes, but only on the same side of the chest where the cancer started to grow.
  • 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, the area around the lungs, or distant organs.

Small cell lung cancer has two main stages. In the limited stage, the cancer is found in only one lung or in nearby lymph nodes on the same side of the chest.

The extensive stage means that the cancer has spread:

  • In a whole lung.
  • To the opposite lung.
  • To the lymph nodes on the opposite side.
  • A fluid around the lung.
  • To the bone marrow.
  • To distant organs.


The symptoms of non-small cell lung cancer and small cell lung cancer are basically the same.

The first symptoms may include:

  • Persistent or worsening cough.
  • Coughing up phlegm or blood
  • Chest pain that worsens when you breathe deeply, laugh, or cough.
  • Ronquera.
  • Difficulty breathing.
  • Wheezing
  • Weakness and fatigue
  • Loss of appetite and weight loss.
  • You may also have recurring respiratory infections, such as pneumonia or bronchitis.

As the cancer spreads, additional symptoms depend on where the new tumors form. For example, if in:

  • 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 problems, or numbness in the arms or legs.
  • Liver: yellowing of the skin and eyes ( jaundice ).

Tumors in the upper part of the lungs can affect the facial nerves, causing a drooping eyelid, a small pupil, or a 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 carries blood between the head, arms, and heart. This can cause swelling of the face, neck, upper chest, and arms.

Lung cancer sometimes creates a hormone-like substance, which causes a wide variety of symptoms called paraneoplastic syndrome, including:

  • Muscular weakness.
  • Nausea.
  • Vomiting
  • Fluid retention.
  • High blood pressure
  • High blood sugar
  • Confusion.
  • Seizures
  • Coma.

Lung cancer and back pain

Back pain is quite common in the general population. It is possible to have lung cancer and unrelated back pain . Most people with back pain do not have lung cancer.

Not all people with lung cancer get 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 caused by pressure from 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 neurological impairment causing:

  • Weakness of the arms and legs.
  • Numbness or loss of sensation in the legs and feet.
  • Urinary and intestinal incontinence.
  • Interference with the spinal blood supply.

Without treatment, back pain caused by cancer will continue to get worse. Back pain may improve if treatment, such as surgery, radiation, or chemotherapy, can successfully remove or shrink the tumor.

Also, your doctor may use corticosteroids or prescribe pain relievers such as acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDs). For more severe pain, opioids such as morphine or oxycodone may be needed.


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 begins to damage your lung tissue. The lungs can repair the damage, but continued exposure to smoke makes it increasingly difficult for the lungs to maintain repair.

Once cells are damaged, they begin to behave abnormally, which increases the likelihood of developing lung cancer. Small cell lung cancer is almost always associated with heavy smoking. When you stop smoking, your risk of lung cancer decreases over time.

Exposure to radon, a naturally occurring radioactive gas, is the second leading cause, according to the American Lung Association.

Radon enters buildings through small cracks in the base. Smokers who are also exposed to radon have a very high risk of lung cancer.

Breathing other dangerous substances, especially for 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:

  • Arsenic.
  • Cadmium.
  • Chrome.
  • Nickel.
  • Some petroleum products.
  • Uranium.

Inherited gene mutations can increase the chance of developing lung cancer, especially if you smoke or are exposed to other carcinogens.

Sometimes there is no obvious cause for lung cancer.

Risk factor’s

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, cigarette smokers are 15 to 30 times more likely to get lung cancer than non-smokers. The more you smoke, the greater the risk. Quitting smoking can reduce that risk.

Breathing secondhand smoke is also a major risk factor. Each 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 natural gas, increases the risk of lung cancer. Radon rises from the ground and enters buildings through small cracks. It is the leading cause of lung cancer in nonsmokers. A simple home test can tell you if the radon level in your home is dangerous.

Your risk of developing lung cancer is higher if you are 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 are a smoker.
  • Radiation therapy prior to the chest.

Lung cancer and smoking

Not all smokers get lung cancer, and not everyone with lung cancer is a smoker. But there’s no question that smoking is the biggest risk factor, causing 9 out of 10 lung cancers.

In addition to cigarettes, cigarette and pipe smoking are also linked to lung cancer. The more you smoke and the more you smoke, the greater your risk of lung cancer.

You don’t have to be a smoker to be affected. Breathing other people’s smoke increases your risk of lung cancer. According to the Centers for Disease Control and Prevention, 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 sent directly to your lungs, where it immediately begins to cause damage. The lungs can usually repair the damage at first, but the continued assault on the lung tissue becomes more difficult to manage.

The chemicals you inhale also enter your bloodstream and travel throughout your body, increasing your risk of other types of cancer.

Former smokers are still at risk of developing lung cancer, but quitting can reduce that risk considerably. Within 10 years of quitting, the risk of dying from lung cancer drops by half.


After a physical exam, your doctor will tell you how to prepare for specific tests, such as:

Imaging tests: An abnormal mass can be seen on x-rays. MRI, CT, and PET. 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 the tumor cells are cancerous. A tissue sample can be obtained as follows:

  • Bronchoscopy – While under sedation, a lighted tube is passed down the throat into the lungs, allowing for a more detailed 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 of the lymph nodes. It is usually done in a hospital under general anesthesia.
  • Needle: Using imaging tests as a guide, a needle is inserted through the chest wall and into suspicious lung tissue. Needle biopsy can also be used to examine lymph nodes.

The tissue samples are sent to a pathologist for analysis. If the result is positive for cancer, further tests, such as a bone scan, can help find out if the cancer has spread and help with staging.

For this test, you will be injected with a radioactive chemical. Abnormal areas of bone will be highlighted on the images. MRI, CT, and PET scan are also used for staging.

Lung cancer treatment

It is generally a good idea to seek a second opinion before starting treatment. Your doctor can help make that happen. If you are diagnosed with lung cancer, your treatment may be managed by a team of doctors that 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 of 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 have a high risk of recurrence.

Stage 2 NSCLC: You may need surgery to remove part or all of your lung. Chemotherapy is generally recommended.

Stage 3 NSCLC: You  may need a combination of chemotherapy, surgery, and radiation therapy.

Stage 4 NSCLC: This is particularly difficult to cure. Options include surgery, radiation, chemotherapy, targeted therapy, and immunotherapy.

Options for small cell lung cancer 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 are eligible for a clinical trial.

Some people with advanced lung cancer choose not to continue treatment. You can still choose palliative care treatments, which focus on treating the symptoms of cancer rather than the cancer itself.

Home remedies for lung cancer symptoms

Home remedies and homeopathic remedies will not cure cancer. But certain home remedies can help alleviate some of the symptoms associated with lung cancer and the 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 are safe for you.

Options can 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 professional, acupuncture can help relieve pain, nausea, and vomiting. But it is not safe if you have low blood counts or take blood thinners.
  • Meditation – Relaxation and reflection can reduce stress and improve the overall quality of life in cancer patients.
  • Hypnosis – Helps you relax and can help with nausea, pain, and anxiety.
  • Yoga – By combining breathing, meditation, and stretching techniques, yoga can help you feel better overall and improve your sleep.

Some people with cancer turn to cannabis oil. It can be infused in cooking oil to drip into the mouth or mixed with food. Or the vapors can be inhaled.

This can relieve nausea and vomiting and improve appetite. Human studies are insufficient and laws for the use of cannabis oil vary from state to state.

Diet Recommendations

There is no specific diet for lung cancer. It is important to get all the nutrients your body needs.

If you are deficient in certain vitamins or minerals, your doctor can advise you which foods can provide them. Otherwise, you will need a dietary supplement. But don’t take supplements without consulting your doctor because some can interfere with treatment.

Here are some dietary tips:

  • Eat when you have an appetite. If you don’t have a significant appetite, try eating smaller meals throughout the day.
  • If you need to gain weight, eat foods and drinks that are low in sugar and calories.
  • Use peppermint and ginger tea to calm your digestive system.
  • If your stomach is easily upset or you have mouth sores, avoid spices and stick to bland foods.
  • If constipation is a problem, add more high-fiber foods.

As treatment progresses, your tolerance for certain foods may change. So can its side effects and nutritional needs. It is worth discussing nutrition with your doctor often. You can also request a referral to a nutritionist or dietitian.

There is no known diet to cure cancer, but a well-balanced diet can help you fight side effects and feel better.


Once cancer enters the lymph nodes and bloodstream, it can spread to any part of the body. The outlook is best when treatment begins before cancer has spread outside of the lungs.

Other factors include age, general health, and how well you respond to treatment. Because the early symptoms can be easily missed, lung cancer is usually diagnosed in later stages.

Survival rates and other statistics provide a broad picture of what to expect. However, there are significant individual differences. Your doctor is in the best position to discuss your point of view.

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. Some people survive much longer than previously seen with traditional treatments.

The following are the estimated 5-year survival rates for NSCLC by stage:

  • Stage 1: 45% to 49%
  • Stage 2: 30% to 31%
  • Etapa 3A: 14%
  • Stage 3B: 5%
  • Stage 4: 1%

Small cell lung cancer is very aggressive. The 5-year survival rate is 14%. The median survival is 16 to 24 months. The median survival for this type of long-stage lung cancer is 6 to 12 months.

The five-year relative survival rate for mesothelioma, a type of cancer caused by exposure to asbestos, is 5% to 10%.