Non-Small Cell Lung Cancer vs. Small Cell: Types, Stages, Symptoms, and Treatment
What Is Lung Cancer?
Lung cancers develop in cells that line the bronchi, and in a part of the lung called the alveoli. Changes to DNA cause cells to grow more rapidly. At first, pre-cancerous cells don’t cause symptoms or form tumors, but they can be identified under a microscope. As the DNA undergoes further change, new blood vessels form to supply the cells, which continue to grow, eventually forming a tumor mass. At that point, a tumor can be seen on imaging tests.
There are two main types of lung cancer: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC).
How Does Lung Cancer Spread?
There are three ways cancer may spread from the original tumor to other parts of the body (metastasis).
- Cancer can invade nearby tissue.
- Cancer cells can travel from the primary tumor to nearby lymph nodes. Then, they can travel through the lymph system to reach other parts of the body.
- Once cancer cells enter the bloodstream, they can travel anywhere in the body.
A metastatic tumor that forms somewhere else is the same type of cancer as the original tumor.
What Is Non-Small Cell Lung Cancer?
According to the American Cancer Society, approximately 85-90 percent of lung cancer cases are NSCLC. There are three types of NSCLC.
Adenocarcinoma is a slow growing lung cancer usually discovered in an outer area of the lung, often before it has a chance to spread. It occurs mostly in smokers, but is the most common form of lung cancer in non-smokers as well.
Squamous cell carcinoma generally occurs in the center of the lung. It tends to develop in smokers.
Large cell carcinoma occurs anywhere in the lung, and usually grows and spreads at a rapid rate.
What Is Small Cell Lung Cancer?
SCLC is so called because of the size of the cells when viewed with a microscope. SCLC usually starts near the center of the chest in the bronchi. It is a fast-growing form of cancer that tends to spread in its early stages. SCLC is rare in non-smokers, and tends to grow and spread much faster than NSCLC.
What Are the Stages of Lung Cancer?
The stages describe how far the cancer has progressed and are used to determine treatment. Earlier stage cancers have a better prognosis than later stage cancers. These are the stages in broad terms:
- Stage 0: Carcinoma in situ is non-invasive and may be cured with surgery alone.
- Stages I, II, III: These stages indicate the size of the primary tumor and/or the extent to which the cancer has spread from its original location.
- Stave IV: The cancer has metastasized to distant organs or tissues, making it more difficult to treat.
What Are the Symptoms of Lung Cancer?
Early stage lung cancer doesn’t always have symptoms. As the cancer progresses, there may be shortness of breath, coughing, coughing up blood, and chest pain. Other symptoms may include:
- fatigue and weakness
- loss of appetite and weight loss
- difficulty swallowing
- pain in the bones and joints
- swelling of the face or neck
How Is Lung Cancer Treated?
Treatment depends on many factors, including stage at diagnosis. If the cancer hasn’t spread, removing a part of the lungs may be a first step. Surgery, chemotherapy, and radiation may be used alone or in some combination. Other treatment options include laser therapy and photodynamic therapy. Other medications may be used to alleviate individual symptoms and side effects of treatment. Treatment is tailored to individual circumstances and may change accordingly.
What Is the Prognosis for Lung Cancer?
The prognosis varies according to the cancer type, stage at diagnosis, and treatment. Survival rates are higher for stage I and stage II lung cancers.
According to the American Cancer Society, patients diagnosed with stage I or stage II NSCLC have a 30-49 percent five-year survival rate.
SCLC is far more aggressive. If not treated, the median survival rate is two to four months, according to The National Cancer Institute. With treatment, ten percent of patients are cancer-free in two years. The overall five-year survival rate of SCLC is between five and ten percent.
Other Types of Lung Cancer
Combined small cell/non-small cell cancer has features of both types, but this is rare. Carcinoid tumors of the lung represent less than five percent of lung tumors, according to the American Cancer Society. These tumors are usually slow-growing and have a better prognosis than NSCLC and SCLC. Carcinoid tumors can often be cured through surgery. Other types of rare lung tumors include sarcomas, carcinomas, lymphomas, and hamartomas.
Other types of cancer may metastasize to the lungs, but this is not lung cancer. Those tumors are the same as the primary cancer.
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