Understanding Lung Cancer: Symptoms, Risks, Prevention, and Treatment

04 March,2024

Lung cancer is one of the most widely diagnosed cancers among women and men. In 2023 alone, over 2.3 million people developed lung cancer. Around 80% of the cases are linked to cigarette smoking, making it a significant risk factor for the disease.

Early diagnosis is the critical element for curing lung cancer. However, if you have been diagnosed in later stages, keep hope. With the advancements in medical sciences, various new therapies that can benefit you are now available. Targeted therapy and immunotherapy, such as CAR T-cell therapy, have shown promising results and are now used to treat lung cancer. 

However, prevention is better than cure. Hence, this blog aims at spreading awareness and knowledge about this fatal disease. It will answer all your questions regarding lung cancer, its types, symptoms, diagnosis, risks, prevention, and treatment.

What is Lung Cancer?

Lung cancer is a complex respiratory disease that develops when the cells in the organ start diving uncontrolled. When the normal functioning of cell division gets hampered due to mutations, the cells keep dividing, ultimately forming a mass or tumor. The two prominent types of lung cancer are –

• Non-Small Cell Lung Cancer (NSCLC): Non-small cell lung cancer is the primary type that accounts for nearly 80-85% of all lung cancer cases. Subtypes of NSCLC are adenocarcinoma, squamous cell cancer, and large cell carcinoma. These cancers are more common in smokers, women, and young patients.
• Small Cell Lung Cancer (SCLC): Small cell lung cancer accounts, or SCLC, for 10 to 15% of all lung cancer cases. SCLC is uncommon in non-smokers. It is a more aggressive form of cancer as compared to NSCLC, as it grows more quickly and is more challenging to treat. In most of the people being diagnosed with SCLC, the cancer has already metastasized and spread to other body parts.

Complications of lung cancer include chest pain, shortness of breath, coughing up blood, and fluid in the chest (pleural effusion).

How is Lung Cancer Diagnosed?

Lung cancer screening is one of the best ways to diagnose cancer in an early stage. It is done mainly by using low-dose CT scans for people who have been chronic smokers or have other associated risks. 

For diagnosing cancer, the oncologist will start by asking about symptoms you are experiencing, taking a past medical & family history, and performing a physical examination. The next step involves running tests like a blood test and chest X-ray. If the physician suspects lung cancer, they will further investigate for an accurate diagnosis. It will include – 

• CT Scan: A computed tomography scan (CT scan) is better than a chest X-ray for detecting lung cancer. It can show tumors that were not visible in the X-ray. It helps in finding the tumor's size, location, position, and shape.
• MRI Scan: Just like a CT scan, an MRI scan also shows images of the soft tissue. However, MRI scans use magnetic rays instead of X-rays, and a more detailed picture is clicked. 
• PET Scan: A PET Scan works by injecting radioactive substances (fluorodeoxyglucose) into the blood. It gets accumulated in the cancerous tissue, making it visible during scans.
• Biopsy: Biopsy involves extracting a sample of the suspected tissue and sending it to the laboratory for examination under the microscope. Biopsy for diagnosing lung cancer can be done in multiple ways, such as: 
  • Needle Biopsy: As the name suggests, tissue is extracted using a needle in this type of biopsy. Two main types of needle biopsy are core needle biopsy (CNB) and fine needle aspiration (FNA) biopsy.
  • Thoracentesis is used to check if the fluid build-up in the chest (pleural effusion) is due to cancer or some other disease. 
  • Bronchoscopy: During bronchoscopy, a thin tube with light is sent through the throat into the lungs to examine and collect tissue samples.
  • Mediastinoscopy and mediastinotomy: Both mediastinoscopy and mediastinotomy are done to take samples from the area between the lungs (mediastinum). In mediastinoscopy, a lighted tube collects samples from the major bronchial tube and lymph nodes near the windpipe. If the area cannot be accessed using a tube, the doctor makes a 2-inch incision near the breastbone and directly removes the sample.
• Molecular Tests: In genomic or molecular testing, the doctor will look for specific gene changes (mutations) in the cancer cells. It helps decide targeted drugs according to the tumor's genetic profile.

What are the Risk Factors for Developing Lung Cancer?

Lung cancer is associated with various risk factors. While you can control the most common risk factors, others can't be changed, such as family history. Risk factors for cancer of the lungs are – 

• Smoking: Smoking is by far the major risk factor for developing lung cancer. Cigarettes, cigars, and pipes increase the chances of lung cancer by 15 to 30 times. Tobacco smoke contains 70+ known carcinogens. 
• Passive Smoking: Secondhand smoke is also a risk factor for lung cancer. Even if you do not smoke, being exposed to passive smoke can lead to cancer.
• Exposure to Radon: Radon is another critical risk factor for lung cancer. Radon gas accumulates in the buildings and living spaces. People residing in such spaces are more prone to develop cancer of the lungs.
• Radiation Therapy in the Past: If you have been through radiation therapy of the chest in the past, your chances of getting lung cancer are higher.
• Family History: If your parents, siblings, and even children have had lung cancer, you are more likely to get it. Apart from genetic reasons, other causes of getting lung cancer are that you are also exposed to smoke, radon, and other carcinogens, as you might share the same space.
• Exposure to Cancer-Causing Agents and Asbestos: Working at places where the amount of asbestos and other carcinogens like arsenic, chromium, nickel, uranium, etc is high also increases the chances of lung cancer.

What Signs and Symptoms Does Lung Cancer Show?

Lung cancer is responsible for approximately 18% of all cancer deaths. The primary reason for it being so fatal is the late diagnosis of the disease. No apparent differentiating symptoms are visible when lung cancer begins and is in its early stages. Therefore, it is advisable to have regular screening tests and check-ups if you are at risk for developing lung cancer.

Some of the notable signs of lung cancer are –

• Persistent Cough: A dry or wet cough with mucus for over two weeks can be a sign of lung cancer.
• Blood in Cough: Another prominent symptom of lung cancer is coughing up blood.  
• Wheezing and Breathlessness: Along with cough, patients experience whistling sounds (wheezing) and shortness of breath.
• Chronic Chest Pain: Chronic chest pain is observed when there is enlargement in the lymph nodes in the lungs. The pain can also radiate to the back and the shoulders.
• Hoarseness and Rough Voice: Lung cancer also affects the voice. It would be best if you do not ignore hoarseness in a voice that lasts over two weeks.

Apart from these, lung cancer can also depict symptoms like bone pain, unexpected weight loss, headaches, fatigue, weakness, etc.

Can Lung Cancer Be Prevented?

No one can guarantee an immunity against lung cancer. However, you can significantly reduce the odds of developing lung cancer by following these preventive measures – 

• Avoid Smoking: Tobacco smoking and consumption is the primary risk factor. If you want to live healthy and cancer-free, it is advisable not to smoke. Even if you have been smoking for quite some time now, quitting can still reduce your chances of developing the disease in the future.
• Avoid Secondhand Smoke: Passive smoking is the phenomenon of inhaling secondhand smoke of other smokers. Ask your relatives and coworkers to quit smoking, and if they don't, the least you can do is ask them to smoke outside. Staying in a smoke-free zone is best for non-smokers to prevent lung cancer.
• Get Radon Level Checked: Radon is a radioactive gas that is colorless and odorless. High levels of radon in homes and places of work are the second most common cause of lung cancer cases. Getting the area where you spend most of your time checked for radon levels is highly recommended for people to prevent lung cancer.
• Healthy Diet and Exercise: Eating a diet rich in fresh fruits and vegetables helps prevent lung cancer and other fatal diseases. A healthy diet and exercise help improve the body's immunity and make it better at fighting cancer cells.

How is Lung Cancer Treated?

Your treating oncologist will make a tailored treatment plan based on your general health, possible side effects, type & stage of lung cancer, and your personal preference. The treatment plan is most likely to be a combination of – 

• Chemotherapy: Chemotherapy involves using medicinal products and drugs to destroy cancer cells. A chemotherapy regimen consists of several sessions/cycles in which the medical oncologist will administer single or multiple drugs. Common drugs used during chemotherapy are docetaxel, gemcitabine, carboplatin, cisplatin, paclitaxel, etc.
• Radiation Therapy: Radiotherapy is a type of lung cancer treatment in which high-energy beams of X-rays or protons kill cancer cells. The radiation oncologist can give therapy before or after the surgery, along with chemotherapy. CyberKnife is the latest advancement in stereotactic radiosurgery, which is now used to deliver precise radiation beams to the lung tumor. 
• Immunotherapy: Increasing the body's immunity to fight cancer cells is one of the best treatment methods as it has the least side effects. Immunotherapy helps the body's immune system identify cancer cells and attack them. CAR T-cell therapy is the latest addition to the non-small cell lung cancer treatment and small cell lung cancer treatment. 
• Targeted Therapy: Targeted therapy works according to the specific genetic profile of the cancerous cells. It involves using drugs that target the genes and proteins responsible for the growth of cancer cells. With more and more clinical trials running in different parts of the world, various new drugs are being developed for NSCLC and SCLC.
• Surgery: The oncosurgeon removes the lung tumor along with some margin healthy tissues. The surgeon might also remove the surrounding lymph node. Different types of surgeries for removing lung tumors are: 
  • Lobectomy: It is the gold standard treatment for lung cancer. In lobectomy, the surgeon removes an entire lobe in which the tumor is present.
  • Wedge Resection: When removing an entire lobe is not possible, the surgeon excises only the tumor along with some healthy tissue. This technique is known as wedge resection.
  • Segmentectomy: It is another way of treating lung cancer when removing an entire lobe is not an option. Segmentectomy is similar to wedge resection. The difference is in the amount of tissue and lymph nodes the surgeon removes.
  • Pneumonectomy: When the tumor is too big and close to the center of the chest, the surgeon might recommend a pneumonectomy (complete removal of an entire lung).

Conclusion

Developing lung cancer is a daunting experience that not only affects you physically but also mentally. Getting timely diagnosis and treatment is crucial to battle the fatal disease. With the availability of personalized medicines and therapies, the lung cancer death rate has declined to some extent. Going for regular screening and following preventive measures is still considered the best way to win over lung cancer.