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An Overview Of The Types Of Lung Cancer

The two main types of lung cancer are small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). However, there are various other subtypes and rarer types.

Lung cancer starts in the lungs or the main airways and leads to uncontrolled cell growth. This can cause tumors to form. While anyone can get lung cancer, the risk is much higher for smokers and those experiencing exposure to secondhand smoke, certain chemicals, or toxins.

In the United States, lung cancer is a leading cause of cancer deaths.

This article explores the main types of lung cancer, including their definitions, prevalence, causes, subtypes, and treatments.

Approximately 15% of all lung cancers are SCLC. This type forms part of a group of cancers that originate from neuroendocrine cells, including neuroendocrine tumors (NETs). These are rare tumors that develop in cells of the neuroendocrine system, which is responsible for hormone production.

SCLC is known for its aggressive nature and rapid growth. It tends to spread quite early on.

Causes

The main cause of SCLC is smoking. It is rare among non-smokers. Other contributing factors may include exposure to carcinogens and a family history of cancer.

While smoking is the largest known risk factor, there are people with an SCLC diagnosis who have never smoked. There are a few known risk factors for non-smokers, though women who are non-smokers are much more likely than male non-smokers to have an SCLC diagnosis.

Carcinogens are substances capable of causing cancer.

SCLC begins in the bronchi, one of the main air passages in the lungs.

Subtypes

There are two subtypes of SCLC: oat cell carcinoma and combined SCLC.

Treatment

Treatment largely depends on the stage of SCLC. Due to its aggressive nature, doctors often treat it with:

NSCLC is a term describing a group of several subtypes of lung cancer. It is the most common type, accounting for approximately 80 to 85% of all lung cancer cases.

Symptoms of NSCLC include a persistent cough and shortness of breath.

Causes

The primary causes of NSCLC include exposure to carcinogens such as:

Genetic factors and a history of lung diseases can also increase the risk.

Subtypes

NSCLC includes several subtypes that originate from different types of lung cells, including:

Adenocarcinoma: The most common subtype of NSCLC, it is prevalent in 40% of all cases of lung cancer. It often occurs in the outer area of the lung and develops in the cells of epithelial tissues.

Squamous cell carcinoma: This subtype often occurs in the central part of the lung or the main air passages, such as the left or right bronchus.

Large cell carcinoma: This subtype can appear in any part of the lung and tends to grow and spread rapidly.

Treatment

Treatment options for NSCLC include:

The choice of treatment depends on the stage of cancer and a person's overall health.

Pancoast tumors, also known as superior sulcus tumors, are a rare form of lung cancer, accounting for approximately 5% of lung cancer cases. They start developing at the top of the lungs.

The tumor invades nearby areas, such as the ribs and spine. The majority of Pancoast tumors are a type of NSCLC.

Causes

The primary risk factors include smoking and exposure to industrial chemicals or asbestos. Pancoast tumors may also occur from other diseases, such as lymphoma or tuberculosis.

Treatment

Treatment for Pancoast tumors usually involves a combination of radiation therapy and surgery. Doctors may also recommend chemotherapy if the cancer has spread.

Carcinoid tumors of the lung are very rare, accounting for less than 2% of all lung cancers. They tend to grow slowly and are more common in younger people.

Approximately 80% of these tumors occur centrally in the lung, while 20% are in other parts of the body.

Causes

The exact cause of carcinoid tumors is unclear, though research suggests a potential link to smoking. Genetic factors and family history can also play a role.

Subtypes

Carcinoid tumors divide into two subcategories: typical and atypical.

Typical carcinoids tend to grow slowly and rarely spread beyond the lungs. Atypical carcinoids tend to grow faster and are more likely to spread.

Treatment

Surgical removal is the primary treatment for carcinoid tumors. Depending on the case, doctors may also consider radiation therapy and chemotherapy.

To determine the type of lung cancer a person has, doctors use several diagnostic tests, including:

These tests can identify the specific cause, type, and subtype of cancer, which helps doctors recommend the best treatment options.

In this section, we answer some frequently asked questions about lung cancer.

What is the most aggressive form of lung cancer?

Healthcare professionals consider SCLC to be the most aggressive form due to its rapid growth and tendency to spread early.

What is slow-growing lung cancer called?

Carcinoid tumors are known for their slow growth, so doctors consider them a type of slow-growing lung cancer.

What are the three main types of lung cancer?

The three main types of lung cancer:

NSCLC

SCLC

carcinoid tumors

What is the life expectancy of a person with lung cancer?

Life expectancy varies greatly depending on the type and stage of lung cancer at diagnosis, the patient's overall health, and response to treatment. Early stage lung cancers have a more positive outlook, while lung cancers at an advanced stage usually have a lower survival rate.

Gene changes in the cancer cells can also affect life expectancy.

Lung cancer has various types and subtypes, each with distinct characteristics, risk factors, and treatment options.

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer, followed by small cell lung cancer (SCLC), which is more aggressive.

Pancoast tumors and carcinoid tumors represent rarer forms with specific treatment strategies. Early detection and accurate diagnosis are crucial in managing lung cancer effectively.

What Are The Signs And Symptoms Of Lung Cancer In Women?

Females and males may experience similar symptoms of lung cancer. Symptoms of lung cancer in females can include shortness of breath, wheezing, hoarseness, and more.

According to the American Cancer Society (ACS), lung cancer is the second most common type in males and females, not counting skin cancer. For both sexes, it is the leading cause of cancer-related death.

In this article, we look at the effects of lung cancer in females, risk factors, treatments, and the outlook.

Males and females experience very similar symptoms of lung cancer, which can include:

Anyone who experiences these symptoms should see a doctor.

Learn more about lung cancer.

The risk factors for lung cancer are similar among males and females. They include:

Smoking and exposure to secondhand smoke remain the most significant risk factors for lung cancer.

An older 2014 review, published in Seminars in Thoracic and Cardiovascular Surgery, proposes that certain genes and hormones contribute to an increased lung cancer mortality rate in females.

Genetics

The researchers have identified several genes that may explain the differing lung cancer rates among females and males. A person can inherit some of these genes, while tobacco exposure activates others.

KRAS

KRAS is a gene; any mutation may make cancerous tumors grow more quickly. A mutation may also make the tumors more likely to spread.

The review suggests that KRAS mutations may make lung cancer growth more aggressive after exposure to estrogen, a female sex hormone, as well as other hormones.

GRPR

The review associates gastric-releasing peptide receptor (GRPR) activity with cancer cell growth.

This receptor is more active in females, and exposure to estrogen may increase its effects.

EGFR

Epidermal growth factor (EGFR) is a protein often present in people with lung cancer. Mutations in the EGFR gene are significantly more common in females than males.

HER2 is a part of the EGFR group of genes present in many adenocarcinoma cases. HER2 has links to poorer survival rates among females with lung cancer.

Estrogen

Researchers have found estrogen receptors in lung cancer cells in males and females.

The same 2014 review on genes and hormones in lung cancer development suggested that estrogen encourages the growth of tumor cells. It has also demonstrated the cancer-suppressing effects of treatments that block estrogen.

Long-term exposure to estrogen may affect lung cancer risk. Factors that may affect estrogen levels include:

the number of pregnancies, if any

the age at first menstruation

the age at which menopause began

The right treatments for lung cancer depend on the cancer's stage at diagnosis.

A surgeon can often remove small tumors that have not spread. Some doctors may recommend chemotherapy or radiation therapy to support surgery and make sure that no cancerous cells remain.

If the lung cancer has spread significantly, surgery is usually not an option. At this stage, a doctor may still recommend radiation therapy to help control complications and reduce pain and discomfort.

Traditionally, there was no difference in how doctors treated lung cancer in males and females.

However, research exploring hormonal and genetic aspects of lung cancer has led to new therapies that may be more effective in females than males.

Learn more about breast cancer that has spread to the lungs.

What are the three warning signs of lung cancer?

Three warning signs of lung cancer include a persistent worsening cough, shortness of breath, and chest infections.

Do you cough up a lot of phlegm with lung cancer?

Lung cancer symptoms can involve coughing up phlegm that may contain blood.

What is life expectancy for lung cancer?

According to the American Cancer Society (ACS), the 5-year relative survival rate for non-small cell lung cancer is:

65% for localized

37% for regional

9% for distant

28% for overall

While the symptoms are similar, the rates of cancer and cancer-related death are different among males and females. More research is necessary to reduce the risk of the disease.

Lung cancer has a poor prognosis.

The ACS use 5-year survival rates to estimate a person's life expectancy after diagnosis. This figure conveys the likelihood that a person with a certain type and stage of cancer will live for at least 5 years after the diagnosis.

For people with non-small cell lung cancer, the overall 5-year survival rate is 28%. For people with small cell lung cancer, the overall survival rate is 7%.

Maintaining a healthful lifestyle and avoiding exposure to smoke can help everyone reduce their risk of developing lung cancer.

Signs and symptoms of lung cancer in females can include shortness of breath, wheezing, fatigue, and more. Males and females tend to experience similar symptoms.

Treatment for lung cancer includes chemotherapy, radiation therapy, depending on the diagnosis and stage. Having a healthful lifestyle, avoiding exposure to smoke, and quitting overall smoking, can help everyone reduce their risk of developing lung cancer.

Stage 4 Lung Cancer

Lung cancer is a type of cancer that grows in your lung tissue. Stages of cancer span from 0-4, with stage 4 being the most advanced stage of lung cancer. Lung cancer is often diagnosed in the later stages because symptoms may be difficult to detect before stage 3 or 4. There are two main types of lung cancer—small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC).

Small cell lung cancer (SCLC) makes up about 10-15% of all lung cancer cases, and non-small cell lung cancer (NSCLC) makes up about 80-85% of lung cancer cases. SCLC tends to spread more rapidly beyond the lungs to other parts of the body. 

Lung cancer is the leading cause of cancer-related death in the United States. However, more research is being done every day to advance treatment and detect lung cancer sooner. Your healthcare team will create a treatment plan based on how advanced your cancer is. Treatment options for stage 4 lung cancer include chemotherapy, radiation therapy, and immunotherapy. 

An oncologist (a doctor who specializes in the diagnosis and treatment of cancer) will perform several tests to determine what stage, or how advanced, your cancer is. Knowing the stage of cancer helps them develop an effective treatment plan. The American Joint Committee on Cancer (AJCC) developed the TNM staging system to determine how advanced cancer is. The system is broken down into three factors: T for tumor: Measures the size and location of a cancerous tumor N for nodes: Determines if cancer cells have spread to the lymph nodes (a group of glands part of the immune system) M for metastasis: Assesses if cancer cells have spread (metastasized) beyond the lungs to other areas of the body The less advanced stages of lung cancer are stages 0-3. Stage 4 lung cancer means the cancer has spread to other parts of the body. There are two types of stage 4 lung cancer: stage 4A and stage 4B. Stage 4A usually means the cancer has spread to the chest, both lungs, the lining around your lungs (pleura), and the lining around your heart (pericardium). Stage 4B means the cancer has spread to one or more tumors outside of your chest or to other lymph nodes and organs. Both non-small cell lung cancer and small-cell lung cancer use the same staging system, though the system is generally not as important in SCLC. Instead, the cancer might be considered to be in a limited stage (cancer is only on one side of your chest) or an extensive stage (cancer has spread to other parts of your body). Stage 4 lung cancer develops when cancer cells from the lung spread to other parts of the body. The cancer cells can move in several ways, including growing into nearby tissue and passing through lymph node or blood vessel walls. Lung cancer is most commonly caused by smoking tobacco. Smoking is linked to 80% of lung cancer deaths in the U.S. Smoking cigars or menthol cigarettes and using chewing tobacco can also cause lung cancer. It is rare to be diagnosed with lung cancer if you have never smoked, but it's possible. Exposure to secondhand smoke, air pollution, and diesel exhaust can also cause lung cancer. Risk Factors There are several environmental and lifestyle risk factors for lung cancer. Depending on the environment you live or work in, you may be able to alter some of the following risk factors: Secondhand smoke: Being physically close to someone who is smoking increases your risk of lung cancer over time. Radon exposure: Radon is a radioactive gas found in soil and rocks. Consider conducting a radon test in your home to check for exposure. Asbestos exposure: People who work in mines, textile plants, and shipyards are at increased risk for asbestos exposure. Asbestos is a chemical commonly used to create commercial and industrial products.  Exposure to chemicals: Inhaling chemicals such as arsenic, beryllium, or diesel exhaust in work environments increases your risk of lung cancer. Beta-carotene supplements: People with a history of heavy smoking may have an increased risk of lung cancer if they take beta-carotene (a compound that gives plants their color) supplements. Radiation therapy: If you have received radiation therapy for another type of cancer, it may raise your risk of lung cancer.  Air pollution: People who live in cities with more air pollution with more exposure to things like diesel exhaust from cars are more likely to develop lung cancer.  Family history: If one of your family members has been diagnosed with lung cancer, your risk is higher.  With stage 4 lung cancer, you can experience the symptoms of lung cancer that people with less advanced stages might experience, as well as symptoms in other parts of your body based on where the cancer has spread. Common symptoms of lung cancer include: A bad cough Hoarse voice Chest pain The presence of blood when you cough Loss of appetite Unintended weight loss Shortness of breath Wheezing  Tiredness or weakness Chronic (long-term or repeated) respiratory infections like bronchitis and pneumonia Because stage 4 lung cancer affects other parts of the body, you may also experience: Bone pain, such as in your back or hips Yellowing of the skin and eyes (jaundice), if the cancer has spread to the liver Swollen lymph nodes in the neck or above the collarbone Headache, weakness or numbness in your arm or leg, dizziness, balance issues, seizures, and other nervous system changes if the cancer has spread to the brain Lung cancer can also cause syndromes as it spreads. For instance, cancer that spreads to nerves in the face can lead to Horner syndrome, which causes eyelid drooping. Other conditions that may occur include superior vena cava syndrome (cancerous tumors that grow in the upper right lung) and paraneoplastic syndrome (a group of syndromes that can affect organs that lung cancer cells have not yet spread to). Several tests help diagnose stage 4 lung cancer. When you develop symptoms of lung cancer, your healthcare provider will likely start by performing a physical exam and asking about your medical history. They will ask questions about the symptoms you are experiencing and any risk factors, such as smoking history. Diagnostic tests for lung cancer include: Blood tests: A complete blood count (CBC) can measure blood cells and tumor markers. Sputum markers: A test of saliva and phlegm can detect tumor markers. Lung biopsy: A small sample of lung tissue is taken and sent to a lab to be tested for cancer cells. Bronchoscopy: A healthcare provider inserts a tubed camera into the lungs to look for signs of cancer. Chest X-ray: Images of the lungs and chest cavity can identify abnormalities like tumors. Magnetic resonance imaging (MRI) scan: This test uses strong magnets to take X-ray pictures of the lungs at several angles. Computed tomography (CT) scan: This radiation test can locate the lung tumor and determine its size. People with a history of heavy smoking may benefit from regular lung cancer screenings with a low-dose CT scan. Positron emission tomography (PET) scan: This nuclear scan locates cancer cells throughout your body and determines how far lung cancer has spread. Several treatment options are available, but stage 4 lung cancer can be hard to cure. Your healthcare provider will discuss the ultimate goal of treatment, which may be to help prolong your life or to let you live more comfortably in the time you have left. The treatment plan will depend on how much your cancer has spread and which areas of the body are affected. Stage 4 NSCLC: Treatment may include a combination of surgery, chemotherapy, radiation therapy, targeted therapy, immunotherapy, photodynamic therapy, and laser therapy. Stage 4A: If the cancer has spread to just one other location, you might have surgery and radiation on the secondary location before treating the cancer in the lung. Stage 4B: If the cancer is more widespread, your treatment may begin with genetic testing. Tumors that test positive for certain gene mutations may have to receive targeted therapy (treatment that uses drugs to target specific molecules). Stage 4B NSCLC: If you have high levels of the PD-L1 protein, your healthcare provider may recommend immunotherapy. Immunotherapy drugs boost the immune response to cancer cells, which can attack the PD-L1 protein in cancerous tumors. Targeted therapy and immunotherapy may be given with chemotherapy (cancer cell-killing drugs are injected into your vein). Treatment for stage 4 SCLC typically does not include surgery or radiation, as they are usually ineffective. Chemotherapy and immunotherapy may improve your symptoms and prolong your life. If your symptoms are breathing-related, radiation may help improve your symptoms. Palliative Care With stage 4 lung cancer, it is not uncommon for the cancer to return even after a period of remission (symptoms of your cancer go away). Palliative care is a type of treatment that focuses on extending and improving your quality of life. The goal of palliative care is not to cure cancer but to ease the burden of symptoms from treatment. Palliative care is different from hospice or end-of-life care. This is supportive care that aims to improve symptoms and reduce pain or discomfort. Palliative care varies from person to person, depending on the toll the cancer takes on your body. Your healthcare provider may prescribe pain medications and anti-nausea medications to reduce symptoms related to the cancer and cancer treatments. If one of your symptoms is difficulty breathing, you may be given airway support and oxygen to open your airways and improve breathing. Experiencing cancer often affects your mental health. A solid support system is important throughout the treatment process. For this reason, your healthcare team may add emotional support and counseling to your palliative care. Most cases of stage 4 lung cancer are not curable. Your prognosis (how the cancer will behave in your body over time) depends on several factors: The type of lung cancer you are living with How the cancer is spreading Your age Your overall health before being diagnosed How your body responds to treatment When predicting outcomes, your healthcare team will consider the five-year survival rate. This estimates the percentage of people who will survive five years after diagnosis. The five-year survival rate is 9% for NSCLC and 3% for SCLC. Preventing all lung cancer cases may not be possible, but you can take steps to lower your risk. Although it can be challenging, quitting smoking can reduce your chances of developing lung cancer later in life. The risk of lung cancer can decrease 30-60% after 10 years of quitting smoking. For long-term smokers, it is also important to not take beta-carotene supplements. Check with your healthcare provider right away if you are experiencing common symptoms of lung cancer. Being diagnosed with stage 4 lung cancer can be a scary experience. A big part of living with stage 4 lung cancer is the palliative care you receive as you go through the treatment process. This can vary depending on multiple factors, including the type of lung cancer you are living with, your age, and how your cancer is progressing. Treatment for stage 4 lung cancer can be mentally taxing. Reach out to your healthcare provider or a loved one for emotional and mental health support if it is not already a part of your treatment plan. Although not many people with stage 4 lung cancer live for long, there are treatments available to extend your life.

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