Lung Cancer

Diagnosing Lung Cancer

At Siteman Cancer Center, we get your diagnosis right the first time. Our expertise in diagnostic testing makes a meaningful difference in the timing and treatments we can use for your cancer.  

Your diagnosis is the starting place for your personalized care plan. We tailor your care specifically for you, your cancer, and your life. 

Learn more about lung cancer, getting a diagnosis, and understanding what it means below.  

What is Lung Cancer?

Lung cancer is a disease that begins in the respiratory system. It’s the second most common kind of cancer in the United States. There are two main types of lung cancer and several sub-types that are rarer. WashU Medicine physicians at Siteman are experts in identifying and treating every kind of lung cancer.  

The two main types of lung cancer are: 

• Adenocarcinoma, or non-small cell lung cancer, is the most common  
• Small-cell lung cancer makes up about 10%-15% of patients 

If your lung screening leads you to need more diagnostic testing, you can come to Siteman for treatment or for a second opinion.  

What Causes Lung Cancer?

WashU Medicine physicians researching the disease were the first in the nation to link a major cause of lung cancer to smoking tobacco. While most understand the disease and smoking are linked, they may not know there are several other factors that can increase risks, too.


Risks aren’t the same as a direct cause of cancer. But they can increase the chances you could get the disease. Many risks of lung cancer have to do with your daily habits, your environment, and exposures to toxic substances like gases, heavy metals, and pollution. 


You can learn more about lung cancer risks and how to reduce it here. 

When Should I See a Doctor?

When you go to your annual checkup, it is a good time to talk to your doctor about lung cancer. If you are at risk, your primary care doctor can refer you for a lung cancer screening. This doesn’t mean you have lung cancer, but it does mean you can be monitored each year to see if anything has changed in your lungs. 

Early lung cancer doesn’t cause symptoms. That makes getting an annual lung cancer screening even more important.  

Lung cancer at later stages does cause symptoms. But some of these symptoms are not specific. If you have one or more of these, make an appointment with your doctor for an exam.   

• Persistent or worsening cough 
• Chest pain 
• Coughing up blood 
• Struggling to breathe 
• Losing weight without trying 
• Fatigue 
• Swollen veins in the neck 
• Facial swelling 
• Difficulty swallowing 

Discover more about getting a lung cancer screening referral from a physician. 

Why Choose Siteman for Your Cancer Diagnosis? 

Siteman sets the standard for lung cancer diagnosis in the region. We use a team approach to determine the exact type of lung cancer our patients have.

Through precision diagnostic testing and pathology, we learn:  

• What type of lung cancer it is, down to the kind of cells  
• Where it is in your body, and if it has spread 
• Genetic information to show which treatments will work best for you

What to Expect During a Diagnosis 

If your screening for lung cancer leads to a referral for more testing, your doctor will use several tests to diagnose lung cancer and determine its type and stage. Based on where the tumor is located, you may have imaging scans, procedures to examine inside the lungs and esophagus, and a biopsy to collect tissue samples.

For an accurate lung cancer diagnosis, we order these tests: 

• Lab work and blood tests 
• Internal tests like biopsies and endoscopy 
• Imaging and scans like CT, MRI, PET-CT, and ultrasound 

Imaging tests 

These tests create precise 2-D and 3-D images inside of the body using sound, radiation, or magnets. Different machines are used depending on what the doctor needs to study.  

• CT scans – Takes detailed X-ray pictures 
• MRI scans – Uses magnets to create detailed images.  
• PET scans – Uses a special sugar solution to find cancer cells 
• PET-CT scans – Combines two types of scans for better pictures 
• Ultrasound – Uses sound waves to see inside your body (often used for tongue tumors) 

Internal tests

Internal diagnostic tests enter your body to learn more about how the cancer is behaving within your systems, organs, and tissues. Some of these tests require you to have light or full sedation so you are comfortable. 

Biopsy: There are different kinds of biopsies. In all biopsies, a surgeon removes a piece of tissue to check for cancer cells. For some of these, you will need to be sedated.  

Bronchoscopy: A bronchoscopy is a kind of biopsy procedure. A physician guides a tube through nose or mouth into the airway and down into the lungs to allow your physician to examine your airways and retrieve a sample of tissue. Experts at Siteman may use an endobronchial ultrasound (EBUS) or robotic bronchoscopy to get more accurate biopsies of the tumor and lymph nodes. You will receive anesthesia for this diagnostic test.  

Mediastinoscopy: A mediastinoscopy is a kind of biopsy. A physician cuts a small incision and guides a mediastinoscope (a small tool) to look inside the chest and collect tissue samples. Patients receive anesthesia for this test so they don’t feel any discomfort. 

Thoracentesis (Fluid Removal from Chest): A thoracentesis procedure removes and studies fluid from the space between the lining of the chest and the lungs. A pathologist studies the fluid and cells it contains under a microscope. This allows physicians to make sure there are no cancer cells in the fluid surrounding the lungs and can provide relief from symptoms. 

Staging Lung Cancer

Staging is an important part of your diagnosis. The stage describes how large the tumor is and whether it has spread. This is crucial because treatment options and outcomes vary significantly based on the lung cancer stage. Cancers caught at earlier stages often have more treatment options and better cure rates. But even at later stages, Siteman can have options for your care, including clinical trials.  

Understanding lung cancer stages

Doctors assign lung cancer a stage from I to IV based on the tumor’s size, location, and whether it has spread beyond the lung. Keep in mind every treatment plan at Siteman is individualized for you. Your team will evaluate if these are the best options for you.

  

Here’s what each stage generally means:

Stage I 

At Stage 1 the cancer is small and confined to your lung. It hasn’t spread to lymph nodes or other parts of your body.

If your cancer is caught at Stage I, it will likely be treated with surgery or stereotactic radiation therapy. Surgery is usually performed using minimally invasive or robotic techniques. Also, radiation therapy has advanced significantly with modern technology.

Stage II 

At Stage 2, the cancer is larger or has spread to nearby lymph nodes but is still contained in the chest.  

WashU physicians at Siteman often treat Stage 2 lung cancer with surgery and chemotherapy, or chemoradiation (a combination of chemotherapy and radiation).

Stage III 

Stage 3 cancers are ones where the tumor is larger or in a location that makes it difficult to remove with surgery right away or at all.

The multidisciplinary teams at Siteman often give these patients chemoradiation to shrink the tumor. They may also receive immunotherapy after the chemoradiation. After these treatments, some patients are eligible for surgery.

Stage IV 

At stage IV, lung cancer has metastasized (spread) to other parts of the body. Patients who have Stage IV lung cancers may:  

• Receive targeted therapy (if they have genomic alterations), 
• Receive immunotherapy or 
• Receive immunotherapy combined with chemotherapy (in those without alterations) 
• Enroll in clinical trials. 

These treatments can improve quality of life and extend it by controlling the cancer.