Rantalliz

Lung cancer

Overview

Lung cancer is one of the most common cancers in many part of the world. It’s caused by harmful cells in your lungs growing unchecked. Treatments include surgery, chemotherapy, immunotherapy, radiation and targeted drugs. Screening is recommended if you’re at high risk. Advances in treatments have caused a significant decline in lung cancer deaths in recent years.

What is lung cancer?

Lung cancer is a disease caused by uncontrolled cell division in your lungs. Your cells divide and make more copies of themselves as a part of their normal function. But sometimes, they get changes (mutations) that cause them to keep making more of themselves when they shouldn’t. Damaged cells dividing uncontrollably create masses, or tumors of tissue that eventually keep your organs from working properly.

Lung cancer is the name for cancers that start in your lungs — usually in the airways bronchi or  bronchioles) or small air sacs (alveoli). Cancers that start in other places and move to your lungs are usually named for where they start (your healthcare provider may refer to this as cancer that’s metastatic to your lungs).

There are many cancers that affect the lungs, but we usually use the term “lung cancer” for two main kinds: non-small cell lung cancer and small cell lung cancer.

 

Non-small cell lung cancer (NSCLC)

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. It accounts for over 80% of lung cancer cases. Common types include adenocarcinoma and squamous cell carcinoma. Adenosquamous carcinoma and sarcomatoid carcinoma are two less common types of NSCLC.

 

Small cell lung cancer (SCLC)

Small cell lung cancer (SCLC) grows more quickly and is harder to treat than NSCLC. It’s often found as a relatively small lung tumor that’s already spread to other parts of your body. Specific types of SCLC include small cell carcinoma (also called oat cell carcinoma) and combined small cell carcinoma.

 

Other types of cancer in the lungs

Other types of cancer can start in or around your lungs, including lymphomas (cancer in your lymph nodes), sarcomas (cancer in your bones or soft tissue) and pleual mesothelioma (cancer in the lining of your lungs). These are treated differently and usually aren’t referred to as lung cancer.

Cancer is usually staged based on the size of the initial tumor, how far or deep into the surrounding tissue it goes, and whether it’s spread to lymph nodes or other organs. Each type of cancer has its own guidelines for staging.

 

Each stage has several combinations of size and spread that can fall into that category. For instance, the primary tumor in a Stage III cancer could be smaller than in a Stage II cancer, but other factors put it at a more advanced stage. The general staging for lung cancer is:

  • Stage 0 (in-situ):Cancer is in the top lining of the lung or bronchus. It hasn’t spread to other parts of the lung or outside of the lung.
  • Stage I:Cancer hasn’t spread outside the lung.
  • Stage II:Cancer is larger than Stage I, has spread to lymph nodes inside the lung, or there’s more than one tumor in the same lobe of the lung.
  • Stage III:Cancer is larger than Stage II, has spread to nearby lymph nodes or structures or there’s more than one tumor in a different lobe of the same lung.
  • Stage IV:Cancer has spread to the other lung, the fluid around the lung, the fluid around the heart or distant organs.

Limited vs. extensive stage

While providers now use stages I through IV for small cell lung cancer, you might also hear it described as limited or extensive stage. This is based on whether the area can be treated with a single radiation field.

  • Limited stage SCLCis confined to one lung and can sometimes be in the lymph nodes in the middle of the chest or above the collar bone on the same side.
  • Extensive stage SCLCis widespread throughout one lung or has spread to the other lung, lymph nodes on the opposite side of the lung, or to other parts of the body.

Metastatic lung cancer is cancer that starts in one lung but spreads to the other lung or to other organs. Metastatic lung cancer is harder to treat than cancer that hasn’t spread outside of its original location.

Most lung cancer symptoms look similar to other, less serious illnesses. Many people don’t have symptoms until the disease is advanced, but some people have symptoms in the early stages. For those who do experience symptoms, it may only be one or a few of these:

 

  • A cough that doesn’t go away or gets worse over time.
  • Trouble breathing or shorness of breath (dyspnea).
  • Chest pain or discomfort.
  •  
  • Coughing up blood (hemoptysis).
  •  
  • Loss of appetite.
  • Unexpained weight loss.
  • Unexplained fatugue (tiredness).
  • Shoulder pain.
  • Swelling in the face, neck, arms or upper chest (superior vena cava syndrome).
  • Small pupil and drooping eyelid in one eye with little or no sweating on that side of your face (Horner’s syndrome).

A cough or pneumonia that keeps coming back after treatment can sometimes be an early sign of lung cancer (though it can also be a sign of less serious conditions). The most common signs of lung cancer include a persistent or worsening cough, shortness of breath, chest pain, hoarseness or unexplained weight loss.

 

Depending on where in your lungs cancer starts, some of these symptoms can happen early (in stages I or II) but often they don’t happen until cancer has progressed to later stages. That’s why it’s important to get screened for lung cancer if you’re at higher risk.

While there are many factors that can increase your risk of lung cancer, smoking any kind of tobacco products, including cigarettes, cigars or pipes is the biggest single risk factor. Experts estimate that 80% of lung cancer deaths are smoking-related.

Other risk factors include:

 

  • Being exposed to secondhand tobacco smoke.
  • Being exposed to harmful substances, like air pollution, radon, asbestos, uranium, diesel exhaust, silica, coal products and others.
  • Having previous radiation treatments to your chest (for instance, for breast cancer or lymphoma).
  • Having a family history of lung cancer.

Diagnosing lung cancer can be a multi-step process. Your first visit to a healthcare provider will usually involve them listening to your symptoms, asking you about your health history and performing a physical exam (like listening to your heart and lungs). Since lung cancer symptoms are similar to many other, more common illnesses, you provider may start by getting blood tests and a chest X-ray.

 

If your provider suspects you could have lung cancer, your next steps in diagnosis would usually involve more imaging tests, like a CT scan, and then a biopsy. Other tests include using a PET/CT scan to see if cancer has spread, and tests of cancerous tissue from a biopsy to help determine the best kind of treatment.

Lung cancer treatments include surgery, radiofrequency ablation, radiation therapy, chemotherapy, targeted drug therapy and immunotherapy.


Surgery
NSCLC that hasn’t spread and SCLC that’s limited to a single tumor can be eligible for surgery. Your surgeon might remove the tumor and a small amount of healthy tissue around it to make sure they don’t leave any cancer cells behind. Sometimes they have to remove all or part of your lung (resection) for the best chance that the cancer won’t come back.

 

Radiofrequency ablation
NSCLC tumors near the outer edges of your lungs are sometimes treated with radiofrequency ablation (RFA). RFA uses high-energy radio waves to heat and destroy cancer cells.

 

Radiation therapy
Radiation uses high energy beams to kill cancer cells. It can be used by itself or to help make surgery more effective. Radiation can also be used as palliative care, to shrink tumors and relieve pain. It’s used in both NSCLC and SCLC.

 

Chemotherapy
Chemotherapy is often a combination of multiple medications designed to stop cancer cells from growing. It can be given before or after surgery or in combination with other types of medication, like immunotherapy. Chemotherapy for lung cancer is usually given through an IV.

 

Targeted drug therapy
In some people with NSCLC, lung cancer cells have specific changes (mutations) that help the cancer grow. Special drugs target these mutations to try to slow down or destroy cancer cells. Other drugs, called angiogenesis inhibitors, can keep the tumor from creating new blood vessels, which the cancer cells need to grow.

 

Immunotherapy
Our bodies usually recognize cells that are damaged or harmful and destroy them. Cancer has ways to hide from the immune system to keep from being destroyed. Immunotherapy reveals cancer cells to your immune system so your own body can fight cancer.

 

Treatments to ease symptoms (palliative care)
Some lung cancer treatments are used to relieve symptoms, like pain and difficulty breathing. These include therapies to reduce or remove tumors that are blocking airways, and procedures to remove fluid from around your lungs and keep it from coming back.

Since we don’t know what causes most cancers for sure, the only preventative measures are focused on reducing your risk. Some ways to reduce your risk include:

  • Don’t smoke or quit smoking if you do. Your risk of lung cancer starts coming down within five years of quitting.
  • Avoid second hand smoke and other substances that can harm your lungs.
  • Eat a healthy diet and maintain a weight that’s healthy for you. Some studies suggest that eating fruits and vegetables (two to six-and-a-half cups per day) can help reduce your risk of cancer.
  • Get screened for lung cancer if you’re at high risk.

Lung cancer screening

You can increase your chances of catching cancer in its earliest stages with sccreening tests. You’re eligible for lung cancer screening if you meet all of these requirements:

  • You’re between the ages of 50 and 80.
  • You either currently smoke or have quit smoking within the last 15 years.
  • You have a 20 pack-year smoking history (number of packs of cigarettes per day times the number of years you smoked).

Ask your healthcare provider about the benefits and risks of yearly screening.

The survival rate of lung cancer depends greatly on how far cancer has spread when it’s diagnosed, how it responds to treatment, your overall health and other factors. For instance, for small tumors that haven’t spread to the lymph nodes, the survival rates are 90% for tumors that are smaller than 1 cm, 85% for tumors between 1 and 2 cm, and 80% for tumors between 2 and 3 cm.

 

The relative five-year survival rate for lung cancer diagnosed at any stage is 22.9%. The five-year relative survival rates by how much cancer has spread is:

 

  • 2% (64% for NSCLC, 29% for SCLC) for cancer that’s confined to one lung (localized).
  • 5% (37% for NSCLC, 18% for SCLC) for cancer that’s spread to the lymph nodes (regional).
  • 7% (26% for NSCLC, 3% for SCLC) for cancer that’s spread to other organs (distant).

Remember that these numbers don’t take into account the specific details of your diagnosis and treatment. Thanks to improvements in detection and treatment, the rates of lung cancer deaths have been rapidly coming down in recent years.