Understanding Lung Cancer 

Each year, more people die from lung cancer than colon, breast, prostate and liver cancer combined. The American Cancer Society estimates that lung cancer makes up approximately 1/4 of all deaths related to cancer.

What is Lung Cancer?

If cells inside your lungs begin to grow abnormally, they can form a cancerous mass, otherwise known as a tumor. As the tumor grows, it may spread to other parts of your body. This process is known as metastasis. The longer your cancer continues to spread and is untreated, the lower your chances become of surviving the disease. That’s why early detection of lung cancer is the key to successful treatment.

Lung Cancer Types

Non-Small Cell Lung Cancer

  • Non-small cell lung cancer (NSCLC) is the most common kind of lung cancer, making up nearly 85% of all lung cancer diagnoses.
  • NSCLC is named for the kind of cells found in this type of lung cancer and refers to how those cells appear beneath a microscope.
  • Even though NSCLC primarily occurs in current or former smokers, non-small cell lung cancer is also the primary type of lung cancer diagnosed in people who have never smoked. 

Small Cell Lung Cancer

  • Small cell lung cancer (SCLC) affects far fewer people than non-small cell lung cancer and almost always occurs in smokers.
  • It accounts for roughly 15% of all lung cancer diagnoses.
  • Like non-small cell lung cancer, SCLC is named for the kind of cells found in cancer and refers to how those cells appear beneath a microscope.
  • The rate of small cell lung cancer diagnoses has fallen in recent decades, reflecting changes in the number of people who smoke and the reduction of workplace hazards.


  • Mesothelioma is an aggressive form of lung cancer that grows in the tissue surrounding the lungs and mostly affects people who were exposed to a mineral called asbestos.
  • Mesothelioma is rare but often fatal since most people don’t discover they have it until cancer has already reached an advanced stage. 

Lung Cancer Causes & Risk Factors

Lung cancer usually affects current or former smokers. Cigarette smoke contains toxic substances, which damage cells in the lungs. Several factors such as the number of cigarettes you’ve smoked, when you started smoking and the total number of years you’ve smoked will affect your risk of lung cancer. Other lung cancer risk factors, for both smokers and non-smokers alike, include second-hand smoke, age, gender and exposure.

Second-Hand Smoke

Even if you aren’t a smoker, you can still develop lung cancer if you’ve been exposed to a substantial amount of second-hand smoke in your lifetime. To minimize your risk, you can always politely ask others to smoke outside or remove yourself from a potentially harmful environment. 

Age & Gender

The older you are the greater your chances become of developing lung cancer. In fact, a very low percentage of people under the age of 45 are diagnosed with lung cancer. The average age of a lung cancer diagnosis hovers around 70. Additionally, Men are at a slightly greater risk of developing lung cancer than women. The American Cancer Society estimates that the chances of a man developing lung cancer at some point within his lifetime are about 1 in 15 whereas the chances for women are about 1 in 17. It’s important to note that those numbers include both smokers and non-smokers.


Sustained exposure to harmful chemical substances, such as asbestos, radon, nickel, soot, tar, arsenic or chromium in your home or workplace greatly increases your chances of being diagnosed with lung cancer.

You can greatly reduce your odds of getting lung cancer by quitting smoking right now, even if you’ve smoked most of your life. 

Lung Cancer Symptoms

Unfortunately, lung cancer symptoms may not show up until cancer has already reached an advanced stage. Not only that, but symptoms may also be mistaken for other, less life-threatening illnesses, such as bronchitis. The following are among the most common signs and symptoms of lung cancer.

  • Chest pain - advanced stages of lung cancer can bring about excessive pain in the lining of the lungs and even in other areas of the body, specifically the bone, causing unexpected pain to appear in your chest, back or shoulders.
  • Coughing up blood - if lung cancer has spread, it can cause severe bleeding in the major airways of the body, which can cause you to cough up blood. This process is also known as hemoptysis.
  • Shortness of breath - lung cancer can spread, blocking major airways of the body and causing excess fluid to build up around the lungs. This makes it harder for your lungs to expand correctly, causing shortness of breath.
  • Persistent cough - a persistent cough that worsens over time or an unexpected change to a chronic cough is a symptom of lung cancer.
  • Excessive fatigue - unexpected fatigue may be an early indicator that your body has developed lung cancer. If you experience a significant change to your overall energy and disposition, it’s recommended you see a specialist immediately for an exam or lung cancer screening.
  • Unexplained weight loss - another sign of lung cancer is drastic weight fluctuation, without changes to exercise or diet.

While one of these symptoms on its own doesn’t necessarily mean that you’ve developed lung cancer, it’s important to take all of them seriously. If you notice any of these symptoms persist, meet with your Mercy doctor right away to see if you qualify for screening. 

Diagnosis & Treatment for Lung Cancer

If you’re experiencing symptoms of lung cancer, it can be overwhelming. Mercy's expert care teams have the knowledge and advanced technology to diagnose and treat your cancer.

Learn about lung cancer diagnosis & treatment options.

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