Small cell and non-small cell are the two main types of lung cancer. There are several key differences, including the outlook.
Smoking is a major risk factor for both types. Of those who receive a diagnosis of small cell lung cancer, 95% have a history of smoking.
Small cell cancers vary, depending on the expression of specific genes.
Some types are more aggressive than others, but generally, small cell cancer is more aggressive than non-small cell lung cancer.
Lung cancer — both small and non-small cell — is the second most common type of cancer among adults in the United States, except for skin cancer. Lung cancer overall accounts for 14% of new cancer diagnoses. Small cell lung cancer accounts for 10–15% of these cases.
Small and non-small cell lung cancers cause similar symptoms. Sometimes, symptoms do not appear until the cancer reaches later stages.
- a hoarse voice
- a persistent cough
- shortness of breath and wheezing
- difficulty swallowing
- a loss of appetite
- chest pain and discomfort
- blood in the mucus brought up by coughing
- swelling in the veins of the face and neck
The symptoms of small and non-small cell cancers are similar, but small cell cancer spreads more rapidly.
A person may be more likely to experience symptoms after lung cancer has reached a later stage.
Does lung cancer affect women differently? Learn more here.
Can shoulder pain be a sign of lung cancer? Find out more.
Causes and risk factors for small and non-small cell cancer tend to be similar.
Smoking is the main risk factor. Smoke and the chemicals that it contains can damage the lungs. This can lead to cellular changes that may result in cancer.
Additional risk factors include:
- exposure to secondhand smoke
- living in an area with significant air pollution
- older age
- past exposure to radiation
- exposure to arsenic and other chemicals
- exposure to asbestos, nickel, chromium, soot, or tar
- having a family history of lung cancer
- having HIV
Smoking is a major risk factor for lung cancer. Find some ideas about how to quit here.
If a person sees a doctor about a persistent cough and other possible symptoms of lung cancer, the doctor will ask questions and take a medical history. They will also perform a physical examination.
They may also request samples of phlegm in order to perform a sputum test. This can help indicate whether cancer is present. The doctor will probably ask the person to provide a sample every morning for 3 days in a row.
They may also perform a biopsy. This involves using a needle to take a sample of cells from the lungs for examination under a microscope. They may do this during surgery.
A biopsy can show:
- whether cells are cancerous
- what type of cancer is present, if any
Sometimes, the doctor requests a bronchoscopy. This procedure involves inserting a tool with an inbuilt camera through the mouth or nose and into the lungs. This helps them see the area and take tissue samples.
They may also carry out other tests to determine whether the cancer has spread beyond the lungs.
What does lung cancer look like? Find out here.
The stage of cancer describes how far it has spread within the body.
There are different ways to describe the stages. One simple way is:
Localized: This means that the cancer is only in one place.
Regional: The cancer has spread to nearby tissues.
Distant: The cancer has spread to other parts of the body, for example, to the liver.
There is also stage 0, or “carcinoma in situ.” At this stage, there may be precancerous cells. These are not yet cancer, but they may become malignant in time.
Stage 0 of lung cancer means that a doctor cannot detect cancerous cells from traditional imaging methods, but tests have revealed precancerous cells in the mucus or elsewhere in the body.
Late stage, or metastatic, lung cancer has spread to other areas of the body. What does this mean, and what is the outlook? Learn more here.
Non-small cell lung cancer
For this type of cancer, doctors usually use a four-stage system.
Stage 1: This signifies that the cancer is only in the lungs.
Stage 2: The cancer has reached nearby lymph nodes.
Stage 3: The cancer has spread to other lymph nodes in the chest, possibly to those in the middle or the other side of the chest.
Stage 4: The cancer has spread to both lungs, to other parts of the body, or both.
Stages of small cell lung cancer
Doctors generally categorize small cell lung cancer with one of two stages:
The limited stage: This means that the cancer is on one side of the chest. It may be in one lung and, possibly, nearby lymph nodes.
The extensive stage: The cancer has spread to other parts of the chest and other organs.
Some doctors use further staging for small cell lung cancer.
Can a person have both types?
Around 5–10% of small cell lung cancer cases are “mixed.” This means that the person has small and non-small cell cancers. Research suggests that it may be easier to treat mixed cancer than small cell lung cancer alone.
After making a diagnosis, the doctor will describe the treatment options and develop a treatment plan.
Factors that affect the plan will include:- the type of cancer
- how far it has spread
- the individual’s age and overall health
- the availability of therapies
- personal preferences
Because each person’s situation is different, treatment will vary accordingly.
Non-small cell lung cancer
Treatment options for non-small cell lung cancer include:
Surgery: A surgeon will remove cancerous cells and any nearby lymph nodes that may be affected. However, if cancer affects a large portion of the lungs, surgery may not be possible.
Chemotherapy: A doctor will administer powerful drugs that can kill cancer cells.
Endoscopic stents: If a tumor has blocked part of the airway, a surgeon may insert a stent.
Radiation therapy: A radiologist will direct a beam of radiation toward malignant cells to destroy them.
Targeted treatments: These drugs target specific genes or other factors that enhance cancer’s ability to grow. Blocking these factors can help stop or delay the growth of some types of cancer.
Immunotherapy: This treatment aims to boost the immune system’s ability to defend the body against cancer. It is an emerging treatment.
Small cell lung cancer
For small cell lung cancer, treatment mainly aims to manage the disease.
- chemotherapy, which is the main treatment
- radiation therapy, which may help boost the effectiveness of chemotherapy or help prevent the cancer from spreading to the brain
- surgery with chemotherapy, when the cancer has not yet reached the lymph nodes, which is rare
Doctors may use a combination of treatments for lung cancer, depending upon an individual’s needs, the stage of the cancer, and the location of the tumor.
Experts use past statistics to estimate the percentage of people who are likely to live for 5 or more years after a diagnosis of cancer. These estimations are called survival rates.
They represent averages and do not take into account factors such as a person’s age or overall health.
Non-small cell lung cancer
For non-small cell lung cancer, the American Cancer Society (ACS) report the following survival rates:
- for localized cancer: 60%
- for regional cancer: 33%
- for distant cancer: 6%
The overall average likelihood of living for at least another 5 years is 23%.
Small cell lung cancer
The ACS estimate the following 5-year survival rates for people with small cell lung cancer:
- for localized cancer: 29%
- for regional cancer: 15%
- for distant cancer: 3%
The overall average likelihood of living for at least another 5 years after a diagnosis of small cell lung cancer is 6%.
Other factors that may affect survival rates include whether the cancer has come back after treatment and a person’s age. Recurring cancer and advanced age can have a negative effect on survival rates.
There are two main types of lung cancer: small cell and non-small cell. Small cell lung cancer is less common and more aggressive.
Quitting smoking — or never smoking — can significantly reduce the risk of developing any type of lung cancer.
If a person has a diagnosis of small cell lung cancer, how long can they usually expect to live?
It depends on the stage of the disease, but overall, the average survival rate is about 1–2 years.
Seunggu Han, MD Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.