Lung Cancer

What is lungcancer?

Lung cancer is a disease caused by uncontrolled cell division in your lungs. Your cells divide and make more copies of themselves as a part of their normal function. But sometimes, they get changes (mutations) that cause them to keep making more of themselves when they shouldn’t. Damaged cells dividing uncontrollably create masses, or tumors, of tissue that eventually keep your organs from working properly.

Lung cancer is the name for cancers that start in your lungs — usually in the airways (bronchi or bronchioles) or small air sacs (alveoli). Cancers that start in other places and move to your lungs are usually named for where they start (your healthcare provider may refer to this as cancer that’s metastatic to your lungs).

Types

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. It accounts for over 80% of lung cancer cases. Common types include adenocarcinoma and squamous cell carcinoma. Adenosquamous carcinoma and sarcomatoid carcinoma are two less common types of NSCLC.
Small cell lung cancer (SCLC) grows more quickly and is harder to treat than NSCLC. It’s often found as a relatively small lung tumor that’s already spread to other parts of your body. Specific types of SCLC include small cell carcinoma (also called oat cell carcinoma) and combined small cell carcinoma.
Other types of cancer can start in or around your lungs, including lymphomas (cancer in your lymph nodes), sarcomas (cancer in your bones or soft tissue) and pleural mesothelioma (cancer in the lining of your lungs). These are treated differently and usually aren’t referred to as lung cancer.

Symptoms

A new cough that doesn’t go away.
Chest pain.
Coughing up blood, even a small amount.
Hoarseness.
Shortness of breath.
Wheezing.

Lung Cancer Risk Factors and Prevention

Smoking is the leading cause of lung cancer, responsible for about 90% of cases. Quitting smoking is the best step for lung health. Secondhand smoke also increases risk, even for non-smokers and former smokers. Prevention: Don’t start smoking, quit if you do, and avoid secondhand smoke.

Radon, a naturally occurring, odorless gas, is the second-leading cause of lung cancer. It enters homes through cracks in the foundation. Prevention: Test your home for radon using inexpensive kits.

Hazardous Chemicals like asbestos, uranium, and certain metals used in workplaces can increase lung cancer risk. Prevention: Use proper safety measures at work and consult health and safety advisors.

Particle Pollution from air pollution, including exhaust fumes, also contributes to lung cancer. Prevention: Support and participate in community efforts to reduce air pollution.

Genetics may also influence lung cancer risk. A family history of the disease should be discussed with your doctor.

Staging

Stage 0 (in-situ): Cancer is in the top lining of the lung or bronchus. It hasn’t spread to other parts of the lung or outside of the lung.

Stage I: Cancer hasn’t spread outside the lung.

Stage II: Cancer is larger than Stage I, has spread to lymph nodes inside the lung, or there’s more than one tumor in the same lobe of the lung.

Stage III: Cancer is larger than Stage II, has spread to nearby lymph nodes or structures or there’s more than one tumor in a different lobe of the same lung.

Stage IV: Cancer has spread to the other lung, the fluid around the lung, the fluid around the heart or distant organs.

Staging

Stage 0 (in-situ): Cancer is in the top lining of the lung or bronchus. It hasn’t spread to other parts of the lung or outside of the lung.

Stage I: Cancer hasn’t spread outside the lung.

Stage II: Cancer is larger than Stage I, has spread to lymph nodes inside the lung, or there’s more than one tumor in the same lobe of the lung.

Stage III: Cancer is larger than Stage II, has spread to nearby lymph nodes or structures or there’s more than one tumor in a different lobe of the same lung.

Stage IV: Cancer has spread to the other lung, the fluid around the lung, the fluid around the heart or distant organs.

Grades

Grade 1. The cells look very like normal cells. They tend to be slow growing and are less likely to spread than higher grade cancer cells. They are called low grade.
Grade 2. The cells look more abnormal and are more likely to spread. This grade is also called moderately well differentiated or moderate grade.
Grades 3 and 4. The cells look very abnormal and not like normal cells. They tend to grow quickly and are more likely to spread. They are called poorly differentiated or high grade.

5-Year Survival Rate

At a glance:

Estimated new cases in 2024	226,650
% of all new cancer cases	11.1%
Estimated deaths in 2024	124,730
% of all cancer deaths	20.2%
5-year relative survival (2014–2020)	28.1%