Introduction:
Small cell lung cancer is one rare but fast-growing lung cancer that arises from the lung tissues. It is also referred to sometimes as oat cell cancer due to the appearance of small, oval-shaped cells similar to oat grains under the microscope. Small cell lung cancer constitutes approximately 15 % of all lung cancers.
What Are Some of the Different Types of Small Cell Lung Cancer?
Small cell lung cancer is classified into two main types such as,
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Small cell carcinoma (the lung cancer that arises from the tissues of the lungs only, and the lesions resemble oat grains).
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Combined small cell carcinoma (cancer arising from the lung tissues combined with one or more components of non-small cell lung carcinoma).
What Are Some of the Major Causes and Risk Factors of Small Cell Lung Cancer?
Various causes are responsible for causing small cell lung cancer. Smoking is a major risk factor. Smokers are at greater risk than nonsmokers. People with a long history of tobacco use are also at higher risk. Several other risk factors include-
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Radiation exposure or exposure to radioactive substances during cancer treatments.
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The individuals whose family members have been diagnosed with lung cancer.
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People who have been exposed to secondhand smoking might develop small cell lung cancer.
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Human immunodeficiency virus (HIV).
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Air pollution.
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Exposure to asbestos, nickel, arsenic, tar, or other chemicals in the working environment.
What Are Some of the Common Signs and Symptoms of Small Cell Lung Cancer?
In the early stages, the disease does not present with any symptoms. However, a patient may present with symptoms as the disease progresses, and these include:
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Hemoptysis (coughing up blood).
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Chronic cough.
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Chest pain.
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Difficulty in breathing.
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Facial swelling.
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Fatigue.
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Loss of appetite.
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Hoarseness of voice.
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Sudden unexplained weight loss.
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Wheezing.
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Swollen neck veins.
Under What Different Stages Can Small Cell Lung Cancer Be Classified?
There are two different stages of small cell lung cancer, and they are as follows:
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Limited Small Cell Lung Cancer- This type of cancer involves one lung and nearby lymph nodes. Other organs are not affected.
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Extensive Small Cell Lung Cancer- In this type, cancer involves both the lung lobes and lymph nodes. It can also include bones, the brain, and other organs.
What Are the Complications of Small Cell Lung Cancer?
The rapid rate of spreading or metastasis increases the risk of complications. It can grow rapidly and spread cancer to other organs involving the liver, brain, bones, and adrenal glands. These cancers are managed by various treatments but cannot be completely cured. Various complications include-
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The lung cancer might recur after the treatment procedure is complete which is harmful for the patient.
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Pain.
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Shortness of breath.
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Pleural effusion (buildup of fluid in the area lining the lungs).
What Are the Various Diagnostic Methods for Small Cell Lung Cancer?
Specific tests are performed to diagnose the presence of small cell lung cancer. It includes-
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Chest X-Ray: Chest X-ray is the initial screening step involved in any type of lung cancer. If the findings reveal any suspicious spots on the lungs, several other investigations are further performed.
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Computed Tomography (CT) and Positron Emission Tomography (PET): Both the tests are performed to detect lung tumors. Computed tomography scans are the primarily recommended scans to diagnose lung cancer. These tests can also help in tracking or recording the spread of cancer.
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Sputum Cytology: Sputum cytology tests help check the presence of cancer cells in sputum; mucus coughed up from the lungs.
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Bronchoscopy: The tube is inserted with a camera at the tip, which provides a detailed picture of the tumor inside the lungs. It also helps to obtain tissue samples for biopsy.
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Biopsy: A technique called needle biopsy (fine-needle aspiration) is used to remove tissue samples from the lungs to rule out the growth of cancer cells. A tissue sample is removed from the lungs using a thin needle and examined under the microscope to check for any presence of cancer cells.
How to Treat Small Cell Lung Cancer?
Various treatment approaches are carried out to treat different stages of cancer. These include:
1) Surgery:
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Surgery is indicated in the case of cancer involved in one lung or both the lungs and lymph nodes.
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During the surgery, lymph nodes are also removed in a few cases.
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The untreated cells left after the surgery are destroyed with radiation therapy or chemotherapy.
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Treatment provided after the surgery is called adjuvant therapy.
2) Chemotherapy:
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In chemotherapy, a series of drugs are used to treat cancer and stop the progression of the disease.
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The chemotherapy is based on the severity and the type of cancer.
3) Radiation Therapy:
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In radiation therapy, high-energy X-rays kill the cancer cells and inhibit their growth.
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External radiation therapy is used to treat small cell lung cancer and is also managed as palliative therapy to relieve symptoms.
Various treatment approaches manage different stages of small cell lung tumors.
1) Limited-Stage Small Cell Lung Cancer:
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In this therapy, initially, a combination of both radiation and chemotherapy to the chest is provided.
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In patients contraindicated to radiation therapy, chemotherapy is given.
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After the completion of chemotherapy, surgery can be done.
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Surgery can be performed, followed by radiotherapy and chemotherapy.
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Later radiation therapy can be performed on the brain after receiving a positive response from the previous chemotherapy treatments.
2) Extensive-Stage Small Cell Lung Cancer:
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Both the immune checkpoint inhibitor and combination chemotherapy are recommended in this therapy.
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Combination chemotherapy.
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Radiation therapy to the chest is provided to patients who have a positive response to chemotherapy.
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Radiation therapy to the brain, bone, spine, or other parts of the body is recommended as palliative therapy to relieve symptoms.
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To prevent the spread of cancer to the brain, radiation therapy to the brain is given to patients received with complete response.
3) Recurrent Small Cell Lung Cancer:
Various treatments are recommended in the case of recurrence of small cell lung cancer, and these include-
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Immunotherapy can be performed with immune checkpoint inhibitors.
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Chemotherapy.
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Radiation therapy is carried out to relieve the symptoms and improve well-being of life.
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Laser therapy, internal radiation therapy, or stent placement are followed to improve the breathing process and improve the quality of life.
Conclusion:
Small cell lung cancer is uncommon but considered a severe life-threatening disease because of the rapidly growing tendency of cancer cells. Therefore, preventive measures such as quitting smoking, eating a nutritious diet, exercising regularly, testing home for radon (natural, odorless radioactive gas), and protecting oneself from cancer-causing chemicals from the environment are recommended.