Lung Condition: GP Lung Cancer

Lung cancer occurs when abnormal cells begin to divide uncontrollably which can result in a lung tumour. Lung cancer can begin in either the windpipe, the main airway, or the lungs themselves and will cause issues with breathing and other lung function as the disease progresses.

There are two main types of lung cancer, and they require vastly different methods of treatment. The majority of lung cancer falls into the category of non-small cell lung cancer (NSCLC), which also consists of multiple subtypes. These subtypes include adenocarcinoma, squamous cell carcinoma, and large cell carcinoma. These subtypes all start from different lung cells but are grouped together due to the similarity in their treatment and outlook.

The other type of lung cancer, which contains about 10% to 15% of all lung cancers, is known as small cell lung cancer (SCLC). This disease, sometimes also referred to as oat cell cancer, tends to grow and spread faster than NSCLC which means that it requires a very aggressive form of treatment.

A common cause of lung cancer is due to smoking tobacco, although there can be other contributing factors as well. Adenocarcinoma, a form of NSCLC, occurs mainly within people who currently or formerly smoked tobacco. This form of lung cancer also happens to be the main type of lung cancer seen within people who don’t smoke.

Another subtype of NSCLC known as squamous cell carcinoma is also linked to a history of smoking. Smoking tobacco is the leading cause of developing lung cancer, with about 80% of lung cancer deaths being caused by cigarette smoking, and others by exposure to secondhand tobacco smoke. However, lung cancer can also be caused by exposure to radon or asbestos, and this risk is increased if the exposure is combined with a history of smoking.

Not everyone who develops lung cancer has smoked tobacco, and many people develop lung cancer without ever being exposed to secondhand smoke. In these cases, the disease typically develops because of exposure to asbestos, radon, air pollution, chemical fumes, or diesel exhaust.

Besides outside influences, lung cancer can sometimes also occur due to gene changes. These can be inherited and can affect the body’s ability to break down cancer-causing cells. Gene mutations may also lead to faulty DNA repair enzymes or cells that create too much EGFR protein, both of which can cause lung cancer.

Certain factors can lead to a higher risk of developing lung cancer. While some of these can’t be controlled, such as your age and family history, other factors can be changed to lower your risk of developing the disease. These include tobacco smoke and secondhand smoke, exposure to radon and asbestos, exposure to cancer-causing agents in the workplace, high levels of arsenic in drinking water, and ingesting certain dietary supplements.

The risk of lung cancer may also increase due to previous radiation therapy to the chest for treatment of other cancers. This risk factor cannot really be avoided, and the benefit of treating one cancer may outweigh the risk of developing another.

Typically, lung cancer in its early stages does not cause any symptoms, so it can be difficult to catch before it progresses. Many common symptoms of lung cancer are signs of a variety of other diseases as well, so it can be difficult to know for sure whether the cause of these symptoms is in fact lung cancer.

Common symptoms of lung cancer include a persistent cough that may get worse, coughing up blood or rust-covered mucus, chest pain, loss of appetite, weight loss, shortness of breath, wheezing, fatigue or weakness, and chronic infections such as bronchitis or pneumonia.

If lung cancer spreads to other parts of the body, it may cause other symptoms such as bone pain felt in the back or hips, nervous system changes from cancer spreading to the brain (which can include headache, numbness of extremities, dizziness, balance problems, and seizures), jaundice from cancer spreading to the liver, and swelling of lymph nodes such as those in the neck or above the collarbone.

Some lung cancers can cause syndromes, which are groups of specific symptoms. Cancer that affects the upper part of the lungs is sometimes called a Pancoast tumor, and is usually a form of NSCLC. These tumors can affect certain nerves in the eyes and face, causing a group of symptoms known as Horner syndrome. These symptoms include drooping or weakness of one upper eyelid, a smaller pupil in the same eye, little or no sweating on that side of the face, and severe shoulder pain.

Another syndrome, called Superior vena cava (SVC) syndrome, is caused by tumors that back up the blood flow in the veins. This can lead to symptoms such as headaches, dizziness, a bluish-red skin color, swelling in the face, neck, arms, and upper chest. This syndrome has the possibility of becoming life-threatening, so it is important to get it checked right away.

To determine whether you have lung cancer, your doctor will first ask about your medical history and conduct a physical exam. If they suspect you may have lung cancer, they will order tests such as a chest X-ray, CT scan, MRI scan, PET scan, or bone scan. These tests can help suggest that you have lung cancer, but a formal diagnosis requires your doctor to look at your lung cells in a lab.

Tests involving the inspection of your lung cells include sputum cytology, where the mucus you cough up is inspected or thoracentesis, where the fluid buildup around your lungs is inspected. Your doctor may also perform a needle biopsy where they will use a hollow needle to extract a sample of suspicious tissue.

Treatment for lung cancer will vary based on whether you have NSCLC or SCLC, although both can be treated with surgery, radiation therapy, immunotherapy, and chemotherapy. They can also both be treated with palliative procedures to relieve symptoms and improve the quality of life, but the specific procedures performed may differ.

For NSCLC, treatment can also include radiofrequency ablation and targeted therapy using medications. The type of treatment used is not only affected by which form of lung cancer you have developed, but also by which stage your disease has progressed to.