Once cancer spreads to other parts of the body (metastasis), it is much harder to treat, which means metastatic lung cancer typically has a five-year survival rate of seven percent.
Lung cancer, also called malignant lung carcinoma, is an uncontrolled growth (proliferation) of cells starting in the lungs. It can arise in any part of the lung, but 95 percent of cancers surface from the epithelial cell lining of the bronchi and bronchioles (the network of airways in the lungs). It is one of the most common causes of cancer-related deaths in both men and women throughout the world.
Metastasis occurs when cancer spreads to other parts of the body beyond the primary tumor (the lungs in this case). Metastatic cancer is typically difficult to treat and has a five-year survival rate of only seven percent, which means that people with this type of cancer, on average, have a seven percent chance to live for at least five years after diagnosis compared to people who don’t have that cancer.
Newer therapies, such as targeted treatments and immunotherapies, have increased the survival rates of metastatic lung cancer. However, the survival rates of lung cancer, in general, are still higher when diagnosed and treated early.
Treatment options for lung cancer include:
- Surgery to remove part or all the lungs
- Chemotherapy (refers to a drug treatment that can kill cancer cells and shrink tumors)
- Radiation therapy (uses high-energy rays to kill cancerous cells)
- Radio-frequency ablation (wherein a thin needle is inserted, and an electric current is used to destroy cancer cells)
- Targeted therapy (targets a specific cell behavior to prevent tumor growth)
- Immunotherapy (helps the body fight cancer cells)
- Palliative therapy (includes pain relief, oxygen therapy and other treatments to help manage symptoms and complications)
What are the different types of lung cancer?
Lung cancers are broadly classified into two types based on the microscopic appearance of tumor cells. These two types of cancers grow, spread and are treated in different ways.
- Small cell lung cancers (SCLC): comprises about 10 to 15 percent of lung cancer cases. It is the most aggressive and rapidly growing of all types and is strongly related to cigarette smoking. SCLCs metastasize rapidly to many sites within the body and are mostly discovered after they have spread extensively.
- Non-small cell lung cancer (NSCLC): the most common lung cancer, accounting for about 85 percent of all cases. NSCLC has three main subcategories designated by the type of cells found in the tumor, which include:
- Adenocarcinomas: the most common type and starts in mucus-secreting gland cells in the lining of the airways.
- Squamous cell carcinoma: develops in the flat cells that cover the surface of the airways and tends to grow near the center of the lung.
- Large cell carcinoma: sometimes referred to as undifferentiated carcinomas, this is the least common type of NSCLC, with cancer cells appearing large and round under the microscope.
What are the warning signs of lung cancer?
Symptoms of non-small cell lung cancer and small cell lung cancer are almost the same, and may include:
- Lingering or worsening cough
- Coughing up phlegm or blood
- Chest pain that worsens when breathing deeply, laughing or coughing
- Hoarseness
- Shortness of breath
- Wheezing
- Weakness and fatigue
- Loss of appetite and weight loss
- Recurrent respiratory infections
- Swelling of the face, neck, upper chest and arms
Tumors at the top of the lungs can affect facial nerves, leading to drooping of one eyelid, smaller pupils or lack of perspiration on one side of the face. Together, these symptoms are called Horner syndrome, which may also cause shoulder pain.
How is lung cancer diagnosed?
People with an increased risk of lung cancer may consider annual lung cancer screening using low-dose computed tomography (LDCT) scans. Lung cancer screening is generally recommended for older adults who have smoked heavily (30 pack-years, defined as one pack per day for 30 years or two packs per day for 15 years), currently smoke or have quit smoking within the past 15 years.
For the diagnosis of lung cancer, the doctor will take the detailed medical history and perform a physical examination of the patient. The tests preferred to diagnose lung cancer are:
- X-ray, computed tomography (CT) and magnetic resonance imaging (MRI) scans
- Sputum cytology
- Biopsy using bronchoscopy, fine needle aspiration
- Mediastinoscopy
- Positron emission tomography (PET) and bone scans