Non-Small Cell Lung Cancer

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What is non-small cell lung cancer?

Lung cancer accounts for about 14% of all new cancer cases each year. This makes it the third most common cancer, after skin cancer and prostate cancer in men and breast cancer in women. Non-small cell lung cancer (NSCLC) is the most common form. About 85% of lung cancers are NSCLC. The other main form is small cell lung cancer. The two cancers differ in the way they grow, their staging, and their treatment. You may also hear the term ‘non-small cell carcinoma’ when referring to NSCLC.

There are three subtypes of NSCLC:

  • Adenocarcinoma is the most common form of NSCLC. It begins in the cells that secrete mucus within the airways. This form is the most common one affecting nonsmokers, but doctors also see it in people who smoke.

  • Large cell carcinoma accounts for 10 to 15% of NSCLC cases. It can grow in any part of the lung and tends to grow and spread more rapidly than other forms. This can make it harder to treat.

  • Squamous cell lung carcinoma, or squamous cell lung cancer is the second most common form of NSCLC. It starts in the cells lining the airways, usually near a main airway (bronchus). These cells are chronically exposed to the carcinogens in tobacco smoke.

Non-small cell lung cancer tends to grow and spread slowly without symptoms in the beginning. When symptoms, such as cough develop, people often mistake it for something else. This makes it very hard to find in the early stages, which contributes to it being the leading cause of cancer-related deaths. However, it is also one of the most preventable cancers because 90% of cases are linked to smoking. Quitting smoking—or never starting—is the single most important thing a person can do to prevent NSCLC.

Finding lung cancer as early as possible offers the best chance of successfully treating it. Seek prompt medical care if you have a cough that persists for more than a few days or worsens with time. You should also see a doctor soon if you have a chronic cough that changes in any way. Seek immediate medical care (call 911) if you cough up blood or bloody or rust-colored mucus.

What are the symptoms of non-small cell lung cancer?

Non-small cell lung cancer can grow in the lungs without causing pain or discomfort. In most cases, it does not cause any symptoms early in the disease. By the time symptoms become noticeable, NSCLC is usually too advanced to be cured.

Common symptoms of non-small cell lung cancer

Once symptoms develop, the most common ones include:

Serious symptoms that might indicate a life-threatening condition

Serious symptoms of lung cancer can also mimic other life-threatening conditions. Seek immediate medical care (call 911) if you, or someone you are with, have any of these life-threatening symptoms including:

Don’t ignore symptoms, even if you think they are probably due to something else like an infection. Seeing your doctor is the only way to know for sure. And getting a timely diagnosis often leads to better outcomes, regardless of the cause of your symptoms.

What causes non-small cell lung cancer?

Normally, cell growth, division and death are highly regulated events and most cells only make new cells at certain times. Cancer begins when normal cells lose that regulation start to grow out of control and make a tumor. However, it is not completely clear what causes these cells to go haywire. Experts believe a combination of genetic and environmental factors like cigarette smoke trigger many cancers. The presence of specific gene mutations, either inherited or that you acquire during your lifetime, can increase the risk of a lung cell becoming a cancer cell and eventually forming a tumor.

What are the risk factors for non-small cell lung cancer?

Most cancers, including non-small cell lung cancer, can affect anyone. However, many cancers also have certain risk factors that make the disease more likely to occur. For non-small cell lung cancer, the main risk factor is smoking in any form. This includes cigarettes, cigars and pipes. About 90% of NSCLC cases occur in current or former smokers. Your risk of developing it goes up the longer you smoke and the more cigarettes per day you smoke. Fortunately, quitting will decrease your risk, regardless of your age.

Other less common risk factors include:

  • Exposure to asbestos

  • Exposure to hazardous chemicals and materials, especially in the workplace

  • Exposure to radon

  • Family history of lung cancer

  • Previous radiation therapy to the chest

Is non-small cell lung cancer genetic?

Lung cancer can run in families, which supports an inherited genetic factor, but it is unclear whether family history relates to inherited gene mutations or to common household exposures, such as secondhand smoke or radon. In fact, most cases of lung cancer are not related to inherited mutations, but to gene mutations a person acquires during their lifetime. The exposures listed above increase the risk of acquiring gene mutations that can lead to lung cancer.

Reducing your risk of non-small cell lung cancer

Cancer prevention and risk reduction focuses on changing risk factors you can control. The strong association between smoking and NSCLC offers an effective way to reduce your risk—stop smoking or never start. Ten years after quitting, your risk will be half that of people who smoke.

If you currently smoke, 10 years can sound impossible. But every journey starts with a first step. Talk with your doctor about strategies and treatments for quitting. Find one that fits your needs and then get started. Decide ahead of time to never quit trying to quit. It may be you need to try a different approach.

You may also be able to lower your risk of NSCLC by:

  • Avoiding or limiting exposure to cancer-causing materials and chemicals—collectively known as carcinogens—by following all safety precautions if you work with potentially hazardous substances

  • Avoiding radon exposure by testing your home and installing a mitigation system if necessary

  • Avoiding secondhand smoke by supporting smokers in your life to stop or working out arrangements to keep smoke away from you and loved ones

  • Eating a healthy diet with plenty of whole grains and fresh fruits and vegetables as part of an overall healthy living strategy

How is non-small cell lung cancer treated?

The stage of the cancer will guide non-small cell lung cancer treatment options. NSCLC stages are occult (hidden), and five more stages using Roman numerals 0, I, II, III and IV. The stage depends on the tumor size, how deeply it has grown into the lung, and whether it has spread to lymph nodes or other organs. Higher numbers indicate more advanced disease. Non-small cell lung cancer stage 4, or IV is quite widespread, affecting distant body sites. Your doctor will order complete diagnostic testing to stage the cancer and plan treatment.

Lung resection is the main treatment for most stages of NSCLC. It involves surgically removing the tumor and some healthy lung tissue around it. In early stages, surgery offers the best chance to eliminate the cancer. Surgery can’t rid your body of the cancer at late stages because it is so widespread. However, it can help relieve symptoms and help you live more comfortably and longer in advanced stages.

Chemotherapy is also a main treatment for all stages of NSCLC. It can help shrink a tumor before surgery and kill any remaining cancer cells after surgery. In late stages, it can be the primary treatment if surgery isn’t possible. Other treatments include radiation therapy, immunotherapy, and targeted therapy. Targeted therapy is medicine that uses specific characteristics or markers on cancer cells to find and kill them. Testing can tell your doctor if targeted therapy is likely to work or not. Doctors most often use immunotherapy and targeted therapy for advanced stages.

It is difficult to cure or eliminate NSCLC with current treatments. Discuss your treatment options with your doctor, including the pros and cons of each. Ask your doctor about clinical trials to find out if you could benefit. Participating in a clinical trial can offer you access to experimental treatments that are not available otherwise.

Is non-small cell lung cancer fatal?

Lung cancer is the leading cause of cancer-related deaths. The stage plays a role in non-small cell lung cancer prognosis or outlook. Survival is highest for people with early stage NSCLC—occult, stage 0, stage I, and stage II. More advanced stages have lower survival rates. However, other factors can influence your prognosis. This includes your age, your overall health, gene changes in the cancer cells, and how well the cancer responds to treatment. Your doctor is the best resource for information about your prognosis.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2020 Aug 27
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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