Lung Cancer

Lung cancer is a type of cancer that originates in the lungs. Most lung cancers start in the cells lining the bronchi, air passageways that lead from the windpipe to the lungs. Cancer can also begin in the bronchioles, which are tiny air tubes, or the alveoli, which is where the lungs and blood exchange oxygen.

Like other cancers, lung cancer happens when cells with damaged DNA grow and multiply. A cell’s DNA can be damaged by environmental factors like ultraviolet rays from the sun or chemicals in tobacco. These genetic abnormalities can be inherited as well.

Fortunately, our body typically detects and destroys damaged cells before they divide. But with age, the immune system becomes less adept at distinguishing between normal and abnormal cells.

But what makes a cancer cell abnormal? Chiefly, cancer cells ignore signals to stop dividing and die (a process called apoptosis). Instead, they grow uncontrollably and hide from the immune system, tricking immune cells into protecting malignant tumors. Cancer cells can even tell blood vessels to feed nutrients and oxygen to cancerous growth. When cancer cells invade other parts of the body, this is called metastatic cancer.

An analysis of the cancer cells collected during a biopsy will reveal what type of lung cancer you have. There are two general types of lung cancer: small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC).

SCLC is the least common form of lung cancer, accounting for just 10 to 15% of all cases5.

Unfortunately, this can spread very quickly. About 70% of patients with SCLC have metastatic cancer by the time they are diagnosed5.

Almost all cases of SCLC are caused by smoking or exposure to secondhand smoke. Individuals who have been exposed to radon, asbestos, and certain workplace chemicals are also at risk.

• Small Cell Carcinoma – a highly malignant form of SCLC that typically starts in the bronchi
• Combined Small Cell Carcinoma – a rare subtype that is less responsive to chemotherapy

NSCLC is the most common form of lung cancer, accounting for about 80 to 85% of all cases⁵. Relative to SCLC, this type of lung cancer is less responsive to treatment.

• Adenocarcinoma – a subtype that starts in the lung cells that secrete mucus
• Squamous Cell Carcinoma – a less common subtype that tends to stay in the lungs
• Large Cell (Undifferentiated) Carcinoma – a fast-growing cancer that is difficult to treat

Cigarette smoking is the leading cause of lung cancer. According to the CDC, 80 to 90% of lung cancer deaths in the U.S. are linked to smoking².

But even non-smokers can develop lung cancer. Though the exact cause may be unknown in these cases, there are certain risk factors strongly linked to the disease.

Lung cancer risk factors include:

• Radon Exposure – Radon is the second leading cause of lung cancer in the United States. This naturally-occurring gas forms in rocks, soil, and water. It can leak into homes and buildings through cracks in foundations. As the gas decays, it emits tiny radioactive particles. When inhaled, these particles damage the cells lining the lungs.
• Occupational Exposure – Some workplace environments like mills, mines, textile plants, and shipyards expose workers to carcinogenic substances on a daily basis. These substances include asbestos, arsenic, diesel exhaust, and some forms of silica and chromium.
• Personal or Family History – If you are a lung cancer survivor, you are at an increased risk of developing second cancer. You are also at an increased risk of developing lung cancer if your parents, siblings, or children have had lung cancer.
• Previous Radiation Therapy – Cancer survivors who had radiation therapy to the chest have a higher risk of developing lung cancer.
• Secondhand Smoke Exposure – Secondhand smoke is tobacco smoke emitted by another person’s cigarette, pipe, or cigar. Prolonged exposure to secondhand smoke at work or home can increase your chances of developing lung cancer by 20 to 30%3.
• Vaping and Marijuana – The long-term effects of vaping, or using e-cigarettes, and smoking marijuana are still being researched. However, experts agree that the toxic chemicals in vape products can cause lung damage. Experts also agree that marijuana smoke contains many of the harmful substances found in cigarette smoke.

There is no sure way to prevent lung cancer. However, you can reduce your risk of developing lung cancer by:

• Not smoking/quitting smoking
• Avoiding secondhand smoke
• Testing your home for radon
• Avoiding carcinogenic chemicals at work
• Eating a balanced diet
• Limiting stress
• Exercising regularly

Some cases of lung cancer are detected during annual screenings. However, lung cancer is more commonly found after the onset of symptoms like chest pain and fatigue. If you have recently experienced a sudden decline in your health, schedule an appointment with your general practitioner. If cancer is suspected, he or she will likely refer you to an oncologist. From there, the oncologist will pursue various avenues for diagnosis.

Common diagnostic imaging tests include:

• Chest X-ray
• CT scan
• MRI scan
• PET scan
• Bone scan
• Blood samples

Diagnosis of lung cancer is typically confirmed with a lung biopsy. During a biopsy, a small tissue sample is collected for lab testing.

Lung cancer staging involves evaluating the size of the tumor in the lung and whether the cancer has been spread to lymph nodes or elsewhere in the body.  Staging is an important aspect of lung cancer treatment and prognosis. Exactly how your lung cancer is staged depends on your cancer type. 

SCLC is typically categorized as either limited stage or extensive stage. In limited stage SCLC, the lung cancer is confined to one side of the chest. In extensive stage SCLC, the cancer has spread widely throughout the lung, to the other lung or chest tissues, or throughout the body.

The most widely used method for staging NSCLC is the TNM classification system. With this system, doctors describe the cancer’s severity using three different categories:

• T describes the primary tumor.
• N indicates if the cancer has spread to nearby lymph nodes.
• M stands for metastasis.

Each letter is then assigned a number, usually 0 to 4, to indicate its severity.

Doctors may also use the stage grouping method to describe NSCLC.

There are five general stages of NSCLC:

• Stage 0 indicates precancerous cells that have not spread into the deeper lung tissue.
• Stage I lung cancer is limited to the lungs and has not spread to the lymph nodes.
• Stage II lung cancer may have spread to the nearby lymph nodes.
• Stage III lung cancer has spread to the lymph nodes and other nearby tissues.
• Stage IV lung cancer has spread from the lungs to other parts of the body.

Lung cancer staging helps your cancer care team develop an appropriate cancer treatment plan. Staging also offers insight into survival rates.

Survival rates indicate the percentage of people with a specific type and stage of cancer who survived for a specific period of time.

Since these percentages are based on samplings of patients, they cannot predict the exact outcome for a single individual. However, they do provide patients with insight into how effective their treatment may be.

SCLC is aggressive, spreading throughout the body quickly. Because of this, the overall five-year survival rate for both limited and extensive stage SCLC is typically <10%⁶.

The five-year survival rates for patients with NSCLC are:

• Stage I, 54%
• Stage II, 35%
• Stage IIIA, 10 to 15%
• Stage IIIB, less than 5%
• Stage IV, less than 2%⁷  

Lung cancer treatment depends on the type and stage of the disease, but may include:

• Surgery
• Radiation
• Chemotherapy
• A combination of these treatments

When the disease is in the early stages and has not spread to the lymph nodes, surgery or focused radiation are the primary treatment options.

However, when the cancer has spread to the lymph nodes or the middle of the chest (mediastinum), treatment typically involves radiation therapy and chemotherapy.

At SERO, our radiation oncologists are dedicated to improving patient outcomes by providing state-of-the-art treatment options for lung cancer care.

Our board-certified physicians are well-versed in advanced radiotherapy technologies such as intensity modulated radiation therapy and image-guided radiation therapy. Many have also been involved in national research specific to lung cancer. This experience allows us to provide a superior patient experience.

To learn more about SERO and our radiation services, call us at 704-333-7376.

Can lung cancer be cured?

If lung cancer is caught in its early stages, there is a chance of complete remission (the disappearance of all signs of cancer). However, remission becomes less likely the later the cancer is diagnosed.

Does vaping cause lung cancer?

Maybe. Research is currently being conducted to examine the link between vaping, or smoking e-cigarettes, and lung cancer. Though no studies currently verify the link between vaping and cancer, experts agree that the chemicals in vaping products damage the lungs.

What are the signs of lung cancer?

The signs of lung cancer include symptoms like coughing, rust-colored phlegm, chest pain, recurring respiratory infections, shortness of breath, wheezing, hoarseness, fatigue, weight loss, and swelling.

What does lung cancer feel like?

In its early stages, lung cancer is asymptomatic. That means patients may not feel anything at all. However, as the disease progresses, most patients begin to feel tired and unwell.

How do you get lung cancer?

Cigarette smoking is the number one cause of lung cancer. But lung cancer can also be caused by exposure to carcinogenic substances, previous radiation therapy, or genetics.