Lungs are vital organs – we need our lungs to oxygenate every cell in our body so that they can each function harmoniously together. When our lungs are compromised by disease and poor health, the rest of our body suffers. That’s why lung cancer is such a devastating and deadly disease.
As the name suggests, this kind of cancer starts in the lungs. All cancers are the result of otherwise healthy cells mutating into cancerous ones. When the DNA of healthy cells becomes damaged, the cells no longer respond to normal growth and death signals. Instead, cancerous cells start to grow and divide quickly. Left unchecked, these cells will continue on a course of overgrowth and abnormal activity. Eventually, they no longer maintain healthy tissue function. Because cancer cells proliferate at abnormally fast rates, they can be hard to stop once they start.
As cancer cells grow, they clump together and form masses of cancerous tissue called tumors. As tumors grow bigger and bigger, they prevent whichever organ they’re affecting from functioning properly. Ultimately, the most significant risk with cancer is that individual cells will break loose from the tumor. When cancer cells break away, they risk entering the bloodstream or the lymphatic system—an immune system responsible for filtering harmful substances.
If cancer cells enter the blood or lymphatic systems, they can end up in other distant parts of the body. This process of cancer cells spreading throughout the body is called metastasizing. All end-stages of cancer, including lung cancer, are the result of cancer cells spreading to distant sites.
Lung Cancer Types
Like with most cancers, there are multiple types of lung cancer. The different types of lung cancers are based on how the lung cancer cells appear and behave under a microscope. Different cancer cell types and their subtypes have unique characteristics and behaviors that determine how quickly they spread, and subsequently, how difficult or easy they are to treat. Ultimately, this is what determines a lung cancer patient’s prognosis (disease outlook).
There are two primary types of lung cancer, each with cell subtypes. Here are the different lung cancer types:
- Non-Small Cell Lung Cancer: Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. NSCLS make up approximately 80-85% of all lung cancers diagnosed. Doctors consider NSCLC easier to treat than small cell lung cancer (SCLC) because these types of cells don’t grow or spread as quickly. This allows doctors more time to administer localized cancer treatments.
There are three NSCLC subtypes:
• Adenocarcinoma: Around 40% of lung cancers are diagnosed as adenocarcinoma subtype. These are lung cancer cells that originate in cells that secrete mucus or other substances. The majority of adenocarcinoma cases are attributed to current or former smokers. It’s also the most common type of lung cancer associated with non-smokers. Adenocarcinoma is more common in women than men and can occur more often in younger people than other lung cancers. Adenocarcinoma is more likely to be caught in its earlier stages compared to other lung cancer cell types.
• Squamous Cell Carcinoma: Squamous cell carcinoma is a lung cancer subtype that starts in the squamous cells of the lungs—flat cells that are found on the inside of the lung’s airways. Squamous cell carcinoma makes up 25-30% of lung cancer cases.
• Large Cell Carcinoma: Large cell carcinoma, also called undifferentiated carcinoma, can start anywhere in the lung. About 10-15% of lung cancer cases are large cell carcinoma. It grows more quickly than the other two NSCLC subtypes, which makes it harder to treat.
There are a few other NSCLC subtypes that are much less common. There are also other cancer types that spread to the lungs, which are considered different cancer types.
2. Small Cell Lung Cancer: Small cell lung cancer (SCLC) starts in the person’s breathing tubes (bronchi). It’s far less common than NSCLC. Up to 15% of lung cancer cases are diagnosed as small cell. SCLC spreads more quickly than NSCLC and is the most aggressive form of lung cancer. It creates large tumors and can quickly spread to distant areas, including the brain, bones and liver. Small cell lung cancer is slightly more common in men than in women and extremely rare in people who have never smoked.
The World Health Organization has two classifications for SCLC: pure and combined. Here are the differences between the two SCLC subtypes:
• Small Cell Carcinoma (Oat Cell Cancer): Most SCLC cases are considered pure, or small cell carcinomas. They’re also known as oat cell cancer. Small cell carcinoma forms in the tissue of lungs. These cells look oval shaped under a microscope, which is why they gave it the name “oat cell.”
• Combined Small Cell Carcinoma: There’s debate about whether combined small cell carcinoma should be considered a subtype of SCLC. However, some research shows that up to 28% of SCLC are considered combined small cell carcinomas. Combined small cell carcinoma means that a tumor contains both small cell carcinomas and at least 10% non-small cells such as adenocarcinoma cell, squamous cells or large cell carcinomas.
15 Lung Cancer Facts
In men and women, lunch cancer is the most deadly. Because of its prevalence, it’s important that all lung cancer patients and anyone at-risk of developing lung cancer be aware of the facts about lung cancer. Follow this lung cancer fact sheet to better understand how lung cancer affects lives.
- Lung cancer is the second most common cancer in men and women, after skin cancer.
- If you combine the number of deaths from colon, breast and prostate cancers, it still won’t surpass the number of deaths from lung cancer.
- 1 in 4 cancer deaths is from lung cancer.
- Lung cancer comprises 14% of new cancer cases.
- The American Cancer Society estimates that there will be 222,500 new cancer cases and 155,870 lung cancer deaths in 2017.
- 2 out of 3 lung cancer cases are in people 65 years or older.
- Less than 2% of lung cancer cases involve people under the age of 45.
- The average age of lung cancer patients at diagnosis is 70 years old.
- 90% of lung cancer cases are attributed to smoking.
- The lifetime risk of developing lung cancer is 1 in 14 in men and 1 in 17 in women (including smokers and non-smokers).
- The overall lung cancer survival rate is 17%.
- The survival rate for advanced cases of lung cancer is only 3.5%.
- 15% of lung cancer cases are diagnosed in the early stages.
- The one-year lung cancer survival rate is 50%.
- There are over 430,000 Americans who have been diagnosed with lung cancer and who are still alive today.
Lung Cancer Causes
It’s common knowledge that smoking cigarettes is the leading cause of lung cancer in both men and women. However, many people may not be aware that there are other risks associated with developing lung cancer. In some cases, people develop lung cancer with no known history of tobacco use or other possible risk factors.
Risk factors are anything that may increase an individual’s risk of developing a disease. These can include certain behaviors, pre-existing conditions or substances. Having a risk factor does not mean that a person will develop the condition.
Here are the known causes and risk factors associated with developing lung cancer:
Smoking Tobacco: Cigarette smoke is full of carcinogens—substances that cause cancer. When a person inhales cigarette smoke, it causes immediate irritation and damage to the lining of the lungs. In many cases, the body can naturally repair this damage.
However, with consistent and prolonged exposure to cigarette smoke, it becomes more and more difficult for the cells in the lungs to repair themselves. Cells can become so severely damaged that they mutate and start to behave abnormally, triggering the development of lung cancer.
Smoking combined with other environmental and genetic risk factors further increase a person’s chance of developing lung cancer.
Secondhand Smoke Exposure: Individuals who live with a smoker such as children, spouses or parents are also at a high risk of developing lung cancer. Breathing in cigarette smoke from a nearby person causes irritation and damage to the lungs. Over time and with consistent exposure, the chances of developing lung cancer by secondhand smoke exposure increase.
Radon Exposure: Radon is a radioactive gas that naturally occurs due to small amounts of uranium in the soil. In some homes and buildings, radon gas can accumulate making occupants susceptible to inhaling this substance. Unsafe levels of radon gas inhaled over an extended period can increase a person’s risk of developing lung cancer.
Chemical Exposure: Many people, largely men, have an increased danger of developing lung cancer due to the nature of their work. In industrial workplaces, employees are potentially exposed to several different types of chemical and toxic substances. Some of the substances that increase the risk of lung cancer include asbestos, silica, arsenic, chromium, nickel and diesel exhaust. The continued exposure to these carcinogens over an entire career span can significantly put people at risk of developing lung cancer.
Air Pollution: Air pollution is another well-known cause of lung cancer. Continued exposure to contaminated air can damage the lungs and make it difficult for them to heal. This risk is much higher in high-density urban areas with high levels of exhaust or industrialized areas that emit coal or other smoke into the air. These pollutants cause tiny, carcinogenic particles to remain in the air increasing the susceptibility of inhalation by people in the area.
Family History and Genetics: Researchers feel that people with a family history of lung cancer (such as a parent or sibling) have a higher risk of developing it themselves. Inherited DNA mutations from parents can make a person pre-disposed to developing lung cancer when combined with other risk factors, such as smoking.
Lung Cancer Symptoms
Lung cancer may be initially difficult to identify because its symptoms often mimic other common conditions like bronchitis or asthma. Additionally, symptoms typically don’t present themselves until the disease has advanced. Many people assume that all lung cancer symptoms are related to breathing and coughing. However, it’s important to know that there are other symptoms apart from respiratory symptoms that can help potentially identify lung cancer.
Here are the common respiratory-related symptoms of lung cancer:
• Persistent cough
• Painful cough
• Coughing up blood or colored mucus
• Shortness of breath
• Chest pain
• Hoarse throat
• Chronic chest infections
In addition to breathing difficulties and coughing, other symptoms of lung cancer may include:
• Back pain
• Shoulder pain
• Unintentional weight loss
• Loss of appetite
When lung cancer has spread to distant sites, it may produce symptoms like:
• Numbness in arms or legs
• Balance problems
• Jaundice (yellow skin) and liver problems
• Lumps near the skin’s surface, especially around neck and collarbones
While most of these symptoms are often associated with much more common and less severe conditions, it’s important to consider the whole picture of symptoms. If you experience any of these symptoms, you should make an appointment with your doctor so lung cancer can be ruled out or acted upon right away.
Lung Cancer Diagnosis
If your doctor suspects you may have lung cancer based on your symptoms, he or she will order a series of tests to look for signs of lung cancer and test for cancer cells. These tests also help doctors rule out lung cancer. Standard lung cancer diagnostic tests include:
• Imaging Tests: X-rays and CT scans help doctors look for abnormal tissue masses or lesions in the lungs.
• Sputum Cytology: Doctors will take samples of sputum produced by a productive cough and examine it under a microscope. In lung cancer patients, sputum may contain lung cancer cells.
• Biopsy: During a biopsy, doctors take a sample of tissue from the lungs to test for the presence of lung cancer cells. Doctors can use different methods to obtain a sample. A bronchoscopy passes a lighted tube through your throat and into your lungs. A mediastinoscopy is a surgical procedure whereby doctors make an incision in the neck and remove samples from the lymph nodes. A needle biopsy uses imaging techniques to guide a needle into your lungs through the chest wall to collect cells.
If diagnostic tests return positive, your doctor will then stage your lung cancer diagnosis based on the test results. Staging is a way for physicians to categorize how advanced your case of lung cancer is. There are four stages of lung cancer:
• Stage 1: Cancer is localized within the lung and has not yet spread to the lymph nodes. The tumor is less than two inches in size.
• Stage 2: The tumor is now larger than two inches. Or the tumor has spread to other structures such as the chest wall, the lung lining (pleura) or the diaphragm.
• Stage 3: Cancer has now spread to other nearby organs or into the lymph nodes away from the lungs.
• Stage 4: Cancer has spread from the affected lung to the other lung or distant parts of the body such as the liver or brain.
Lung Cancer Treatments
After diagnosis and staging, your doctor will determine a prognosis (disease outlook). Based on your prognosis, your doctor will put together a treatment plan that gives you the best chance of survival or quality of life. Your treatment plan may include a multimodal approach, meaning more than one type of treatment is used.
Here are possible lung cancer treatments:
Surgery: Doctors may recommend surgery to remove as much of the tumor as possible from the lungs. Depending on how advanced your cancer is, doctors may remove part of the lung, an entire lobe of the lung and they may remove the affected lung completely.
• Chemotherapy: Chemotherapy is a cytotoxic (anti-cancer) drug that kills cancer cells. Chemotherapy may be administered intravenously or in pill form. Chemotherapy usually requires multiple rounds over a several week period. It’s often used after surgery (adjuvant therapy) to kill any remaining cells that the surgeon couldn’t remove.
• Radiation Therapy: Using high-energy beams, radiologists target the affected lung from outside the body. The radiation destroys the DNA of lung cancer cells, which prohibits them from multiplying. Like chemotherapy, radiation therapy is often used after surgery to prevent lung cancer from recurring (coming back).
With ongoing research and clinical trials, there are emerging technologies and drug treatments that can help give lung cancer patients more options for survival. Talk to your oncologist about emerging and targeted drug therapies.
Oncology at Gettysburg Cancer Center
If you’ve been diagnosed with lung cancer, it’s important to seek out the best cancer care possible. Gettysburg Cancer Center is a leading cancer treatment center that’s dedicated to patient care. Our experienced team of physicians and professional staff can provide a range of services to diagnose and treat lung cancer. From radiation therapy to pharmaceutical technology, Gettysburg Cancer Center is here to support you through to your follow-up care. Call Gettysburg Cancer Center today at 717-334-4033 to schedule an appointment.