A cancerous tumor that develops in lungs cells is known as lung cancer. This condition causes the cells to divide in the lungs uncontrollably. This leads to the growth of tumors that reduce a person's ability to breathe.
Sometimes, cells in lung change and no longer behave or grow normally. These changes may lead to benign (non-cancerous) tumours such as papilloma and hamartoma. However, in some cases, these changes in the lungs cells can cause cancer.
Lung Cancer Types
Lung cancer is categorised into small cell lung cancer and non–small cell lung cancer based on the type of cell in which cancer occurred.
Non–small Cell Lung Cancer
- Non–small cell lung cancer starts typically in glandular cells on the outer part of the lung. This type of cancer is called adenocarcinoma.
- It can also start in thin, flat cells called squamous cells. These cells line the bronchi, which are the large airways branching off from the trachea (windpipe) into the lungs. This cancer is called squamous cell carcinoma of the lung.
- Large cell carcinoma is also a type of non–small cell lung cancer, but it is less common.
- There are some rare types of non-small cell lung cancer, including sarcomatoid carcinoma and sarcoma.
Small Cell Lung Cancer
- This type of cancer usually starts in the cells lining the bronchi in the centre of the lungs. The main types of small cell lung cancers are combined small cell carcinoma (mixed tumors with squamous or glandular cells) and small cell carcinoma.
- Other types of cancer can also spread to the lungs, but this is not treated as primary lung cancer. Cancer that starts in some other part of the body and spreads to the lung is called lung metastasis.
Lung Cancer Symptoms
Generally, it is not easy to recognise the symptoms of lung cancer as they are somewhat similar to other diseases. Some of the symptoms are:
- Swelling of the face or neck
- Chest pain
- Coughing up blood
- Shortness of breath
- Chest pain
- Loss of appetite and weight loss
- Difficulty swallowing
- Fatigue and weakness
- Pain in the bones and joints
- appetite loss
Lung Cancer Causes
Some common causes of lung cancer are:
- Tobacco use
- Active smoking or passive smoking
- Exposure to some chemicals such as silica, arsenic, asbestos, etc. used in specific industries
- Exposure to the radioactive gas, radon
Lung Cancer Stages
The staging of cancer indicates how far it has spread and its severity. This staging helps clinicians to decide the treatment for the best results.
Staging definitions may vary, but doctors typically stage non-small cell lung cancer (NSCLC) using the tumor size and the spread.
Hidden or occult: Cancer does not show on scans, but cancerous cells might appear in the mucus or phlegm and may have reached other parts of the body.
Stage 0: Abnormal cells are identified only in the top layers of cells lining the airways.
Stage I: At this stage, a tumor had developed in the lung, but its size is under 5 cm and has not spread to other parts of the body.
Stage II: The tumor is still smaller than 5 cm but might have spread to lymph nodes, or the tumor is smaller than 7 cm and spread to nearby tissues, but the lymph nodes are still not infected.
Stage III: At this stage, the Cancer has already spread to the lymph nodes and also reached other parts of the lung and its surrounding area.
Stage IV: At this stage, the Cancer has spread to distant body parts, such as the brain or bones.
Small cell lung cancer has its own categories, extensive and limited, referring to whether cancer has spread within or outside the lungs.
Test and Diagnosis
If a person is experiencing symptoms that could indicate lung cancer or the doctor identifies a suspicious lesion during a lung cancer screening, then the doctor recommends several diagnostic tests to confirm the next steps.
Imaging studies: Positron emission tomography (PET) and Computed tomography (CT) scans might reveal areas of lung tissue that have cancerous cells. Bone scans are recommended to analyse cancer growth. Doctors may use these scans to track the progress of treatment or to ensure cancer has not returned after treatment.
Tissue sampling: If a doctor found a suspicious lesion during an imaging study, they may take a sample of tissue to test for potentially cancerous cells.
Different ways are available to take a tissue sample, and the method generally depends on the location of the lesion.
Lab testing: A doctor may ask for blood testing sputum testing to check the presence of lung cancer.
A doctor uses this information to determine the type of lung cancer and how advanced it has become.
The importance of early diagnosis
Early diagnosis of lung cancer can be lifesaving for the patient. It is essential to identify cancer before it becomes advanced and spread to the other parts of the body. If this spread or metastasis has taken place, then the treatment of lung cancer will become more difficult.
Sometimes, doctors recommend a high-risk person to have lung cancer screenings. These screenings are performed using a low-dose CT scanner. It is not necessary that all these persons are diagnosed with lung cancer, but this can help doctors identify lung cancer earlier.
Lung Cancer Treatment
Lung Cancer must be treated as soon as possible. Through Lung Cancer treatment, the doctor aims to remove the hazardous cancerous cells and stop their growth. Sometimes, doctors recommend a combination of medicines and treatments.
Chemotherapy: During Chemotherapy, the medications are injected in the vein to kill cancerous tumors. Low medication doses may be combined with radiation while higher doses are generally used for advanced cancer stage. This treatment is preferred when cancer has spread throughout the body. Chemotherapy is also used as a follow up after the surgery.
Radiation: High powered energy beams like protons or X-Ray are used to kill the tumors. These beams can be directed from outside your body, or you could put them in seeds, needles, and place them inside your body at the site of cancer. This can be used to kill off cancer cells that remain after surgery.
Radiation therapy may be used with Chemotherapy or alone. Undergoing radiation therapy can leave the patient with early menopause. The patient may ask the doctor about the methods to preserve the eggs before treatment.
Surgery: Surgery aims to remove all the cancerous cells within the body. Some of the surgery procedures, that doctor can follow are given below:
- Lobectomy: In this surgery, the entire affected lung lobe is removed.
- Segmental Resection: In lung cancer surgery, segmental resection refers to removing a section of a lobe of the lung. It is also called Segmentectomy.
- Wedge Resection: In Wedge Resection, a Part of the lung lobe containing cancer and a small amount of healthy tissue around is removed.
- Pneumonectomy: In Pneumonectomy, an entire lung is removed.
Targeted Drug Therapy: This is an advanced treatment option. The used drugs target the abnormalities in the cells to do their work. The targeted therapy drugs can be used along with regular chemotherapy drugs.