Lung cancer occurs when diseased cells grow out of control and form tumors in the lungs.

About 8 in 10 lung cancers are non-small cell lung cancer (NSCLC). The different NSCLC subtypes include:

• Lung adenocarcinoma: Cancer starts in epithelial cells. These cells on the outside of the lungs make mucus. Lung adenocarcinoma is the most common type of lung cancer.
• Large cell carcinoma: These large cancer cells form anywhere in the lungs and quickly spread.
• Squamous cell carcinoma: Cancer starts in flat squamous cells that line the inside of the lung airways.
• Undifferentiated NSCLC: An undifferentiated or “not otherwise specified” (NOS) diagnosis means physicians can’t determine the precise cancer type.

Small cell lung cancer (sometimes called oat cell cancer) accounts for up to 15% of lung cancer diagnoses. This cancer type grows and spreads faster than NSCLC.

Less commonly, carcinoid tumors, lymphomas and sarcomas can also appear as types of lung cancer.

Lung cancer doesn’t always cause symptoms, especially during the early stage.

Common Symptoms

Lung cancer signs and symptoms include:

• Lung cancer signs and symptoms include:
• Chest pain that worsens when you cough, laugh or take a deep breath
• Chronic cough that gets worse
• Chronic or recurrent respiratory infections, such as bronchitis or pneumonia
• Coughing up blood
• Fatigue
• Hoarseness, wheezing or shortness of breath
• Loss of appetite and unexplained weight loss

Smoking is a known cause of lung cancer. But the condition affects nonsmokers, too. Up to 40,000 Americans who never smoked or who smoked very little receive a lung cancer diagnosis every year.

Additional common risk factors for lung cancer include:

Physicians often start with imaging tests, such as chest X-rays and CT scans, to check for lung tumors. You may also get an MRI or a combination positron emission tomography (PET) and CT scan to see if cancer has spread outside your lungs (metastatic lung cancer).

Physicians use the following tests to definitively diagnose lung cancer and determine the type:

• Sputum cytology: A lab specialist checks samples of sputum (mucus that you cough up) for cancer cells.
• Bronchoscopy: A physician threads a bronchoscope (flexible tube with a light on the end) through your mouth or nose to examine your lungs. Tiny tools inside the scope help the physician remove tissue or fluid samples to check for cancer cells.
• Needle aspiration/core biopsy: A physician removes tissue from the lung tumor using a hollow needle inserted through your skin. A lab specialist checks the tissue for cancer.
• Robot-assisted bronchoscopy: UC Davis is unique in that we can use complex robotic platforms to diagnose and remove lung cancer in a single surgery. The procedure begins with a CT scan to create a 3D map of your lungs. A software program then generates the safest and most efficient route through the lung to reach nodules or masses.
• Thoracentesis: A physician inserts a needle through your skin to remove fluid between your lungs and chest wall. A lab specialist checks the fluid for cancer.
• Thoracoscopy: A physician inserts a thoracoscope (flexible tube with a light and video camera on the end) through a small chest incision. The camera enables the physician to view your lungs and chest.

After getting a sample, experts in our Department of Pathology and Laboratory Medicine examine it to determine if you have cancer.

Lung cancer treatments vary depending on the cancer stage, type and tumor location. Other deciding factors include your lung function and overall health.

Surgical removal of the cancerous lung tumor is often an option. Our surgeons commonly remove the tumor through small incisions. High-definition cameras and complex robotic platforms aid the procedure.

Medications used in chemotherapy and immunotherapy treat higher-staged lung cancer. These drugs are called systemic therapy because they flow through your circulatory system.

Some people get systemic therapy before surgery to shrink a tumor (neoadjuvant therapy). You may also get systemic therapy after surgery to lower the risk of cancer coming back (adjuvant therapy).

Radiation therapy uses radioactive materials to destroy cancer cells. Physicians may use radiation therapy as a main treatment for NSCLC (with or without chemotherapy) if surgery isn’t possible. It also treats SCLC and lowers the risk of cancer spread.

When you come to our cancer center’s Thoracic Oncology Program, you gain access to a nationally recognized team of experts and the latest lung cancer treatments and services. Our experts in chest, lung and cancer care work together to customize a treatment plan that offers you the best outcomes.

The UC Davis Comprehensive Lung Cancer Screening Program (CLCSP), part of our Lung Cancer – Lung Nodule Early Detection (Lung-LEAD) Clinic, provides yearly screenings for people at the highest risk for lung cancer. We use low-dose chest CT scans (LDCT) to detect lung cancers when they are at an early stage and before symptoms appear, when treatment is most effective and has the best chance for cure.

You may benefit from this program if you: 

• Are a current or former smoker between the ages of 50 and 77 (sometimes up to age 80, depending on insurance) 
• Smoked one or more packs of cigarettes a day for 20 years or longer 
• Stopped smoking within the past 15 years

In addition to lung cancer screening, the best way to prevent lung cancer is to not use tobacco products and to avoid exposure to secondhand smoke.

If you smoke or use other tobacco products, it’s never too late to quit. Your lungs get healthier, and your risk for different cancers decreases, with each smoke-free day. Experts in our Stop Tobacco Program (SToP) offer the resources, support and tools you need to succeed.

To schedule a lung cancer screening:

• Ask your provider to fax the required referral to 916-703-2254.  
• Call 916-734-0655 to make an appointment.