The lungs are the air-filled, spongy organs located on either side of the chest. The primary function of the lungs is to get air from the atmosphere and pass the oxygen into the bloodstream.
Cancer that forms in the lung tissues is known as lung cancer. It is the leading cause of death in both men and women.
There are different type of lung cancers:
Non-small cell carcinoma: This type of cancer affects the cells that line the airway passage of the lung (bronchi). There are different types of non-small cell carcinoma:
Adenocarcinoma: It is a type of lung cancer that starts in glandular cells that line the alveoli. They are usually caused by cigarette smoking, although it can often occur in non-smokers, women at younger ages.
Squamous cell carcinoma: It is also known as epidermoid carcinoma. It begins in flat, thin squamous epithelial cells that line the airways of the lungs. Cigarette smoking is the main cause of this type of cancer.
Large cell carcinoma: It isa less common type of non-small cell lung cancer and usually begins from neuroendocrine cells present in the lungs. It multiplies and may spread early.
Small cell carcinoma: This type of cancer spreads early and is usually linked to cigarette smoking. They are aggressive in nature, and surgery is less effective in this type of lung cancer.
Lung carcinoid tumors: These carcinoid tumors affect special cells in the lungs called neuroendocrine cells. When in a healthy state, these neuroendocrine cells get signals from the nervous system to make hormones necessary for lung function. This is a rare type of cancer and is treated differently from small cell and non-small cancers.
Cancers targeting the lymph nodes, supportive tissue, or smooth muscles of the lungs are also rarer and require different treatment.
What are the causes and risk factors of lung cancer?
Exact cause of lung cancer is not known. However, there are certain risk factors associated with lung cancer.
Smoking: Smoking tobacco is the leading risk factor for lung cancer. The risk is more in patients where they smoke and also consume alcohol regularly.
Second-hand smoke: People who don’t smoke but stay with people who smoke around them are equally exposed to the cancer-causing agents, although in smaller amounts.
Family history: People who have someone in blood relation with lung cancer are at higher risk.
Occupational hazards: Exposure to arsenic, asbestos, beryllium, chromium, nickel, soot, or tar in the workplace, increases the risk.
Radiation exposure: Exposure to radiation like radiation therapy to the chest, specific imaging testing like CT scan.
HIV infection: People suffering from HIV infection are prone to develop lung cancer
Air pollution: People living in cities are more exposed to pollution and are at greater risk of developing lung cancer.
What are the symptoms of lung cancer?
Different people may experience different symptoms of lung cancer. In case a person has a primary tumor in the lung, symptoms will be related to the lungs. In case cancer has spread to different body parts, symptoms will be linked to that organ. Some of the common symptoms of lung cancer are:
Coughing that gets worse or doesn’t go away.
Blood in cough.
Pain in the chest.
Shortness of breath.
Feeling very exhausted all the time.
Unintended weight loss.
How is lung cancer diagnosed?
When you visit your doctor with presenting symptoms, he may like to do a physical examination.
Physical examination: The doctor will take your health history, including smoking history, eating habits, past illness, etc. He might perform a physical exam to assess lung function and your overall health. This may listen to your lung sounds and suggest blood tests. Although blood tests cannot diagnose lung cancer, they will help the doctor determine if there is an infection. In case of a productive cough, he may ask you to send the sample of the mucus to the pathology to look for any cancer cells.
After physical examination, if your doctor suspects lung cancer, he may recommend other tests to confirm the diagnosis and know about the extent of the cancer spread. Below are procedures that may be used to confirm the diagnosis:
CT scan: This test uses a special dye medium that helps with a clear image of the body parts from different angles. It can help in seeing the detailed images of soft tissue and blood vessels. CT scan is used to measure the tumor size and helps look for the spread of the tumor to different body organs.
Magnetic resonance imaging (MRI): An MRI uses magnetic fields to produce detailed body images. It helps in measuring the size of the tumor and also to look for the spread of cancer.
Chest X-ray: X-ray uses a small amount of radiation to create a picture of the structures inside of the body. It helps the doctors to find out if the lung has cancer.
After the imaging techniques confirm the presence of cancer. Your doctor will ask you to go for a biopsy to know about the type of lung cancer as this will help the doctor in planning the treatment.The process of obtaining a tissue or fluid sample is called a biopsy. There are various methods of performing biopsies of lung tumors:
Bronchoscopy: In this procedure, a thin, flexible tube with a tiny camera attached is inserted through the mouth/nose and down into the lungs to get a small tissue sample. This technique is usually done under mild sedation.
Needle biopsy: In this procedure, a small sample of cells is taken out from the affected site with the help of a small needle; it is guided by a CT scanner.
Fine needle aspiration (FNA): In this procedure, a small fine needle is placed into the tumor and a small amount of tissue is aspirated and sent to pathology.
Thoracentesis: With the help of the needle, fluid around the lungs is drawn and sent for pathology to look for the presence of cancer cells.
Endobronchial Ultrasound (EBUS): In this procedure, a bronchoscope with an attached ultrasound device is used to look for cancer inside nearby chest lymph nodes. EBUS is usually performed at the same time as bronchoscopy and is done under general anesthesia.
Video-assisted thoracoscopic surgery (VATS): This minimally invasive surgical procedure where a tiny camera is used to get tumor samples that are otherwise difficult to access. It is done under general anesthesia.
Symptoms of lung cancer are often mistaken with different health problems like pneumonia or bronchitis. Due to this, many cases are diagnosed at an advanced stage. It is always advisable to visit the right specialist. The health care specialist will suggest specific tests, and based on the proper diagnosis, he may guide you to the right specialist like an oncologist in case of lung cancer.
What are the next steps after confirmation of cancer?
After confirmation of cancer, your doctor may ask you to go for additional tests like a positron emission tomography (PET) scan to determine the spread of the tumor to the lymph nodes or other areas of your body. These tests also help in determining the grade of cancer.
Positron emission tomography (PET) or PET-CT scan: A PET scan uses a small amount of radioactive sugar material, injected into the patient’s body. This sugar substance is then used by cells, and a scanner then detects this substance to process images of the inside of the body.
What are the stages of lung cancer?
Staging of the lung cancer depends on the type of lung cancer
Non-small cell lung cancer has been divided into 4 main stages:
Stage 1: Cancer begins in the lung, but it has not spread outside the lung.
Stage 2: Cancer begins in the lung and nearby lymph nodes.
Stage 3: Cancer is found in the lung and lymph nodes in the middle of the chest.
Stage 3A: Cancer is present in the lymph nodes, but only on the same side of the chest where cancer initially started growing.
Stage 3B: At this stage, cancer has spread to lymph nodes above the collar bone or present on the opposite side of the chest.
Stage 4: Cancer is found in both lungs, in the area around the lungs, or in other organs.
Small-cell lung cancer (SCLC) has two main stages.
Limited stage: Cancer is present only in one lung or nearby lymph nodes on the same side of the chest.
Extensive stage: Cancer has spread throughout one lung to the opposite lung, lymph nodes on the opposite side, fluid around the lung, bone marrow, and distant organs.
How is lung cancer treated?
There are different treatment options available. Patients are usually given a combination of treatments like radiotherapy, chemotherapy, surgery, etc. The best treatment option depends on various parameters such as stage of cancer, patient body response to treatment, etc. Below are some standard treatments available:
Radiation therapy: This treatment procedure uses high-energy x-rays or other types of radiation to kill the cancer cells and keep them from growing.
External radiotherapy: External machine is used to send radiations to the affected part of the body.
Internal radiotherapy: Certain devices such as seeds, wires, needles, etc., are placed on or near the affected area where they emit radiation.
Chemotherapy: In chemotherapy, drugs are used to prevent cancer cells from growing, either by inhibiting them from multiplying or killing the cancer cells. Some of the commonly used drugs are Carboplatin and Paclitaxel.
Targeted therapy: This treatment uses drugs and other substances that identify and attack the cancer cells. As this treatment focuses on cancer cells, it is less harmful in comparison to radiation and chemotherapy. Some of the common drugs used in the treatment of lung cancer are Tabrecta, etc.
Immunotherapy: In this procedure, the patient’s own immune system is used as a tool to fight against the disease. Substances that boost the immunity of a person are made in the laboratory and then used to enhance the person's immunity to help fight cancer. This treatment is also known as biological therapy or biotherapy.
Patients suffering from non-small cell lung cancer are usually treated with surgery, radiation therapy, chemotherapy, targeted therapy, or a combination of these treatments.
Patients suffering with small cell lung cancer are usually treated with chemotherapy and radiation therapy.
Treatment depending on the stage of the cancer
Treatment for non-small cell lung cancer
Stage 1 NSCLC: At this stage, the following treatment is considered:
Surgery is done.
Chemotherapy is recommended for patients with a high risk of recurrence.
Stage 2 NSCLC: At this stage, the following treatment is considered:
Surgical removal of the affected part of the lung.
Chemotherapy is recommended.
Stage 3 NSCLC: At this stage, the following treatment is considered:
Combination of radiation therapy, chemotherapy, and surgery is recommended.
Stage 4 NSCLC: At this stage, the following treatment is considered:
Combination of radiation therapy, chemotherapy, immunotherapy, target therapy, and surgery are recommended.
What to expect after the surgery?
Your stay in hospital will be around for 6-7 days after the operation. Lung cancer surgery is a big operation, and it might take you approximately six months to fully recover. This is the time where your body is in the recovery phase. The physiotherapist will visit you and teach you exercises that will prevent complications and enhance recovery.
Once you are discharged from the hospital, please follow the below-mentioned guidelines:
Rest: Allow yourself to have extra rest for the first few weeks after the surgery.
Medicine: Take all the medications on time as suggested by the doctor. This will help you to recover well.
Sponge bath: Till all your drains are removed and sutures healed, take a sponge bath. Once your doctor approves a regular bath, you may go for it.
Exercise: Regularly do exercises taught to you by your physiotherapist. In case you experience pain or difficulty doing it, get in touch with a physiotherapist.
What is the survival rate of lung cancer?
The survival rate of the patient depends on the factors like type and stage of cancer.
Non-small cell cancer
5-year survival rate for patients with localized (cancer is limited to one lung) cancer is 60%.
5-year survival rate for patients with regional (cancer has spread outside the lung or to the lymph nodes) cancer is 33%.
5-year survival rate for patients with distant (cancer has moved farther, such as to other lung, brain and bones) cancer is 6%.
Small-cell lung cancer
5-year survival rate for patients with localized (cancer is limited to one lung) cancer is 29%.
5-year survival rate for patients with regional (cancer has spread outside the lung or to the lymph nodes) cancer is 15%.
5-year survival rate for patients with distant (cancer has moved farther, such as to other lung, brain and bones) cancer is 3%.
Treatments for all stages are available. Also, survival rates don’t always predict your future. It is always recommended to discuss with your doctor about the diagnosis and best treatment option available.
How to keep a check on the recurrence?
As lung cancer has a high recurrence rate, to keep a check on it, your doctor will recommend you some tests to monitor the cancer status after treatment. Be vigilant about the follow-ups and take all the medicine and precautions suggested by the doctor. Go for regular screening as any change in the reports may trigger the need to devise a new treatment plan.
Prevention of lung cancer is not possible. However, by making some lifestyle modifications, you can lower the risk.
Smoking: Smoking is linked to a high risk of lung cancer, as well as many other cancers and health problems.It is the most important thing you can do to avoid lung cancer.
Second-hand smoke: Inhaling air when people are smoking around is known as passive smoking or second-hand smoke. It is advisable to avoid this scenario and try to make the home smoke-free.
Screening: If you have a family history of lung cancer, consider going for regular screening tests. Discuss with your doctor about the screening process, and he will recommend the most suitable test for you.
Manage weight: Being obese or overweight increases the risk of cancer. Indulge in some form of physical activity like exercising, yoga, etc., to keep your body fit.
Diet: People eating food that is high in fruits, vegetables, and whole grains, etc., will keep you fit and healthy.
Be careful at work: Ensure your workplace does not have exposure to substances which are known to cause cancer such as chromium, arsenic, and nickel can increase your risk of developing lung cancer, especially if you're a smoker.
You won't be able to identify lung cancer because it typically doesn't cause signs and symptoms in its most initial stages. When it is at advanced stages, you can observe the symptoms.
Signs and symptoms of lung cancer may consist of:
A recent cough that doesn't go away
Coughing up a small or large amount of blood
Shortness of breath
Losing weight without trying
Types of lung cancer
Doctors have divided lung cancer into two major types based on lung cancer cells' appearance under the microscope.
The two common types of lung cancer are:
Small cell lung cancer: This cancer occurs almost exclusively in heavy smokers.
Non-small cell lung cancer: This cancer is more common than small cell lung cancer. It is an umbrella term for several types of lung cancers. Non-small cell lung cancers constitute squamous cell carcinoma, adenocarcinoma, and large cell carcinoma.
After examining you, the doctor will make treatment decisions based on which significant type of lung cancer you have.
Diagnosing lung cancer
After a physical examination, your doctor will inform you how to prepare for specific tests, such as:
Imaging tests: The doctor may recommend an X-ray, MRI, CT, and PET scans for more detailed scans to produce more detail and find smaller lesions.
Sputum cytology: Microscopic examination of a cough can determine if cancer cells are present.
Biopsy: A small tissue is removed from the lung to determine if tumour cells are cancerous.
Bronchoscopy: A lighted tube is passed down your throat and into your lungs while under sedation, consequently allowing more thorough examination.
Mediastinoscopy: The doctor will make an incision at the base of the neck to insert a lighted instrument and surgical tools used to take samples from lymph nodes.
Needle: The doctor may insert a needle through the chest wall and into the suspicious lung tissue with the help of imaging tests as a guide.
The tissue samples will be sent to the lab for analysis to determine the staging of cancer.
The doctor will select a treatment plan for you, depending on your general health and the type and stage of cancer.
Following are the treatments for lung cancer:
Surgery for Lung Cancer:The surgeon will remove all or some cancerous tissue inside the lung and a healthy tissue margin.
Radiation treatments: A powerful beam of energy is used to target and eliminate cancerous cells before and after surgery. It is exerted to kill any cancer cells that may be left after surgery. If cancer has attained an advanced stage or other areas of the body, then radiation therapy may help relieve symptoms, such as pain.
Chemotherapy: Chemotherapy is implemented to kill cancer cells and limit the growth of cancer cells. In the chemo, a combination of drugs is given in a series of treatments over weeks or months, with breaks in between to recover. Chemotherapy provides relief to patients by intake of drugs, which goes into the blood and spread through the body.
Targeted Therapy: These drugs mainly affect cancer cells and not active cells. These drugs block the abnormalities causing cancer cells to die.
Stereotactic body radiotherapy: Stereotactic body radiotherapy, also known as radiosurgery, is used for small lung cancers and people who can't undergo surgery. Radiation is aimed at many angles at cancer to eliminate it.
Immunotherapy: In immunotherapy drugs support your immune system to attack cancer. Immunotherapy works for people with locally advanced lung cancers and cancers that have spread to other parts of the body.
Supportive (palliative) care: To provide relief from pain and other symptoms of a severe illness, palliative care is provided. Palliative care can be used while undergoing surgery and chemotherapy.