What is Lung Cancer?

The lungs are two large sponge-like organs in our chest that enable us to breathe. We take in oxygen-rich air through our nose, via the windpipe (trachea) into air sacs where gaseous exchange takes place. Oxygen is taken into the body and carbon dioxide is discharged into the air. Toxic substances in cigarette smoke damage both the windpipe and lungs. When these cells become abnormal, cancer can be developed. As the cancer cells grow, they invade into neighboring organs such as the heart and chest wall. It also spreads to lymph glands around the airway and to other parts of the body.
What are the signs and symptoms of lung cancer?
The main symptoms are:
- General weakness, tiredness and unexplained weight loss
- A cough that doesn’t go away and gets worse over time
- Blood in sputum (Haemoptysis)
- Shortness of breath, wheezing, or hoarseness
- Recurrent chest infection and fever
- Constant chest pain
- Loss of appetite
- Symptoms from metastases of lung cancer — swollen liver, pallor, lymph gland enlargemen
How is Lung Cancer diagnosed?

The diagnosis is made using one or more of these tests:
- History and Physical Examination
- Chest X-ray
- Sputum cytology Examination of the sputum under the microscope may reveal cancer cells.
- Bronchoscopy A fibro-optic tube with a light source at its tip is passed through the nose into the airways. Suspicious lumps can be biopsied – a small piece of the lump is taken for microscopic examination.
- Transthoracic needle biopsyUnder CT scan guidance, a needle is inserted into the chest to biopsy suspicious lumps in the lungs.
- Mediasternoscopy or thoracoscopic surgery These are invasive procedures which require general anaesthesia and hospitalization. They are necessary if earlier tests are negative.
- Imaging studies CT (Computerized tomography), MRI (Magnetic resonance imaging) and PET (Positron emission tomography) scans are performed to determine the extent of the cancer.
The severity of the Lung Cancer is measured by:
A. Stage
Stage | Extent of Spread | 5 year Survival Rate (%) |
---|---|---|
0 | Cancer is localized and only in the first few layers of cells. | 70 - 80 |
I | Cancer is confined to the lungs and surrounded by normal tissue. | 50 |
II | Cancer has spread to nearby lymph nodes. | 30 |
III | Cancer has spread to the chest wall, diaphragm, nearby organs, blood vessels, lymph nodes in the mediastinum or the other side of the chest or neck. | 5 - 15 |
IV | Cancer has spread to more distant sites in the body. | Less than 2% |
B. Histologic Type
There are two main types:
- Non-small cell lung cancer (NSCLC)
- Small cell lung cancer (SCLC)
How is Lung Cancer treated?
Stage | Treatment |
---|---|
I & II |
The common treatments are open surgery, chemotherapy and radiotherapy. However, for those who can’t tolerate or do not want to take common sugery, the preferred treatment is minimally invasive treatment, including cryotherapy, interventional therapy, microwave ablation, combined therapy of chinese medicine and western medicine, etc for lung cancer stage 1 or stage 2. |
III |
In LUNG CANCER STAGE 3, it is safe to take minimally invasive treatment to remove the cancer cells because it only brings 2mm trauma, lesser side effects than chemotherapy and radiotherapy. Comprehensive treatment is better than the single treatment because cancer has spread to lymph nodes in middle of chest. Single treatment might not well meet patient’s need to kill the cancer cells to the greatest extent. Taking cryotherapy or microwave destroys the localized tumor in lung and interventional therapy helps kills the residual cancer cells spread to other lymph nodes or organs. |
IV |
In LUNG CANCER STAGE 4 , the tumor has spread to the other lung, or elsewhere outside the chest (metastasis). Open surgery is not effective as a form of treatment. Rather, minimally invasive treatment becomes a good option in lung cancer stage 4. Cryotherapy, microwave, interventional therapy, nanoknife therapy is applicable to treat lung cancer stage 4 and doctor team will first discuss patient’s condition and give a recommended treatment plan according to their physical condition, willing and other factors. |
- Non-small cell lung cancer (NSCLC)This is not as aggressive as SCLC. It tends to grow and spread more slowly. If discovered early, surgery or radiotherapy may offer a chance of cure.
- Small cell lung cancer (SCLC)This is an aggressive cancer, which spreads to the blood stream early. Hence it is usually treated with chemotherapy and not surgery. It is often an advanced disease when diagnosed. The main treatments are radiation and chemotherapy. Results are poor. The average survival rate is less than 2 years.
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If you still have questions about Lung Cancer treatment, please click the following links or have online consultation with our experts to get detailed answers.
What are the treatment options for Lung Cancer patients?
Which kind of treatment has fewer side effects?
Different treatment options for different stages of Lung Cancer
Prevention and treatment for metastatic Lung Cancer.
How to improve the survival time and living quality of Lung Cancer patients?