Small-Cell Lung Cancer: Types, Staging, Causes, Risk Factors, Symptoms, Diagnosis, Treatment, Recovery

Medically Reviewed by Dr. K on 30 March 2021

Small Cell Lung Cancer

Lung cancer is a disease that occurs when the cells in the lungs begin to grow rapidly and uncontrollably. Cancer can damage any portion of the lungs, and is one of the leading cause of cancer mortality of both men and women.

Lung cancer is divided into two groups. SCLC, also known as small-cell carcinoma, accounts for 10% to 15% in all lung cancer cases. The remainder is caused by NSCLC, or non-small cell lung cancer.


2 Types of SCLC

There are 2 main types:

  • Small-cell carcinoma (oat cell cancer)
  • Combined small-cell carcinoma

Both contain a diverse range of cells that grow and spread in a variety of ways. They're given names based on how the cells appear under a microscope.

The following characteristics differentiate small-cell lung cancer from non-small-cell lung cancer:

  • Small-cell lung cancer grows rapidly.
  • Small-cell lung cancer spreads quickly.
  • Chemotherapy (the usage of medications to destroy cancer cells) and radiation therapy are important therapies for small-cell lung cancer (using high-dose X-rays or other high-energy rays to kill cancer cells).
  • Small-cell lung cancer is often linked to distinct paraneoplastic syndromes (a collection of symptoms that result from substances produced by the tumor).

Small-Cell Lung Cancer Causes

  • Tobacco smoke is the leading source of both small-cell lung cancer and non-small-cell lung cancer. Small-cell lung cancer, on the other hand, is more directly related to smoking than non-small cell lung cancer.
  • Lung cancer is induced by secondhand cigarette smoke. As opposed to those who are not subjected to secondhand smoke, many who live with a smoker have a 30% increased risk of developing non-small cell lung cancer and a 60% increased risk of developing small cell lung cancer.
  • People who mine uranium are more likely to develop lung cancer of any form, but small-cell lung cancer is the most frequent. Uranium miners who smoke have a higher prevalence of developing lung cancer.
  • Small-cell lung cancer has been related to radon exposure (an inert gas created by the decay of uranium).
  • Asbestos exposure significantly raises the likelihood of lung cancer. Asbestos contamination along with tobacco smoking raises the risk even further.


Small-Cell Lung Cancer Symptoms

Before seeing a doctor, people with small-cell lung cancer usually have symptoms for 8 to 12 weeks.

Local tumour development, spread to surrounding regions, distant spread, paraneoplastic syndromes, or a combination of these factors may cause symptoms.

  • The below are some of the symptoms that may occur as a result of the tumor's local growth:
    • Cough
    • Coughing up blood
    • Shortness of breath or difficulty breathing
    • Chest pain worsened by deep breathing
  • The below are signs and symptoms of cancer spreading to surrounding areas:
    • Compression of the nerve that feeds the vocal cords causes a hoarse voice.
    • Shortness of breath triggered by compression of the nerve supplying the diaphragm muscles, or stridor caused by the lungs filling with blood (sound produced by turbulent flow of air through a narrowed part of the respiratory tract) resulting from trachea (windpipe) or greater bronchi compression (airways of the lung)
    • Compression of the oesophagus causes difficulty swallowing (food pipe)
    • Compression of the superior vena cava causes swelling of the face and hands (vein that returns deoxygenated blood from the upper body)
  • The following symptoms can occur as a result of distant cancer spread, depending on the location of spread:
    • Headaches, distorted vision, fatigue, vomiting, weakening of any limb, neurological changes, and seizures are all signs of spread to the brain.
    • Back pain may arise if the infection extends to the vertebral column.
    • Paralysis and lack of bowel or bladder control may occur if the cancer spreads to the spinal cord.
    • Bone pain will occur if the disease spreads to the bone.
    • The spread of cancer to the liver will cause pain in the right upper abdomen and jaundice (yellowing of the skin or eyes).
  • The following are symptoms of paraneoplastic syndromes:
    • Symptoms may or may not be specific to a particular organ structure.
    • Fatigue, lack of appetite, and weight gain or loss are nonspecific symptoms.
    • Severe muscle weakness.
    • Problems with walking or balance.
    • Changes in mental status.
    • Skin colour, texture, and facial features changes


When to Seek Medical Care

  • If you have any of the following signs, you should see a doctor:
    • Shortness of breath
    • Coughing up blood
    • Unintentional weight loss
    • Changes in your voice
    • New cough or change in the consistency of a cough
    • Unexplained persistent fatigue
    • Unexplained deep aches or pains
  • Seek emergency care if you experience any of the following symptoms:
    • Coughing up large amounts of blood
    • Chest pain
    • Sudden shortness of breath
    • Sudden or severe weakness of any limb
    • Sudden vision problems
    • Seizures

Exams and Tests for Lung Cancer

  • The below are examples of initial examinations and tests for suspected lung cancer:
    • Medical, surgical, occupational, and smoking history
    • Physical examination
    • Chest X-ray
    • CT scan of the chest: An X-ray scanner connected to a monitor takes a sequence of detailed pictures from various angles of the interior of the chest. Computed tomography, computerised tomography, and computerised axial tomography are all terminology used to describe this test.
    • Thoracentesis: The lungs are enclosed inside a sac. Fluid may build up in this sac as a result of lung cancer. Pleural effusion is the medical term for this. This fluid may contain cancer cells in cancer patients. A needle is used to remove the fluid and is then checked for cancer cells.
    • Bronchoscopy: This is a procedure that looks for irregular areas within the trachea (windpipe) and large airways in the lungs. A bronchoscope (a thin, flexible, lighted tube with a tiny camera on the end) is placed down the windpipe via the nose or mouth. The device should then be inserted into the lungs' airways (bronchi). During bronchoscopy, the doctor checks the airways for cancers and performs a biopsy (a collection of cells removed for analysis under a microscope).
    • Lung biopsy: Bronchoscopy might not be able to detect a tumour on the lung's periphery. Instead, a biopsy sample must be obtained by inserting a needle into the chest wall into the tumour. A transthoracic needle biopsy is the name for this procedure.
    • Mediastinoscopy: The aim of this treatment is to see how much the tumour has spread through the mediastinum (the area of the chest between the lungs). A tube is inserted behind the breastbone via a narrow cut in the lower part of the neck during mediastinoscopy. This area's lymph nodes (small bean-shaped structures located in the body) are sampled to inspect for cancer cells.
  • Exams and examinations are conducted after a patient is diagnosed with lung cancer to see whether the cancer has progressed (metastasized) to other organs. These measures assist in determining the cancer's stage. Since lung cancer treatment is determined by the stage of the cancer, staging is crucial. The following tests can be used to diagnose the spread of cancer:
    • Blood tests: Full blood count provides information about the type and count of different types of blood cells, serum electrolytes, kidney function, and liver function.  These measurements may be able to identify the location of metastasis in some cases. These tests are often necessary to evaluate organ functions prior to beginning treatment.
    • CT scan of the chest and abdomen: An X-ray scanner attached to a monitor takes a collection of detailed pictures from various angles of areas inside the body. A dye can be injected into a vein by the doctor. The organs or tissues can be given a contrast agent to absorb such that they may be seen more distinctly on the scan.
    • MRI: MRI is a form of imaging that produces high-resolution images of the inside of the body. From various perspectives, a collection of informative pictures of locations within the body are taken. The distinction between an MRI and a CT scan is that an MRI utilises magnetic waves for the operation, while a CT scan uses X-rays.
    • Radionuclide bone scan: This test helps the doctor to assess whether the lung cancer has spread to the bones. A tiny dose of radioactive material is injected into the vein, then it passes into the bloodstream. If the disease has progressed to the bones, radioactive material accumulates in the bones and can be observed by a detector.
    • PET scan: To see how the cancer has advanced, a small dose of radioactive material is injected into the bloodstream and the metabolism of the organs is assessed.
    • Video-assisted thoracoscopy (VATS): Through small openings in the chest, a doctor can insert a lighted tube with a video camera. It's a technique for studying the lungs and other tissues. It's even possible to do a biopsy.
    • Endobronchial ultrasound (EBUS): Through your mouth, a doctor inserts a flexible tube with a film camera and an ultrasound into your windpipe and lungs. They will examine the lungs and lymph nodes in the region, as well as take a tissue biopsy.



  • The cancer staging offers valuable details regarding the patient's prognosis and aids the doctor in planning the best treatment. Small-cell lung cancer is divided into two types, unlike most tumours, which are graded from stage I to stage IV.
    • Limited stage: The tumour is only on one side of the chest, the tissues between the lungs, and nearby lymph nodes at this time.
    • Extensive stage: Cancer has spread from the lung to other areas of the body at this point.


Small-Cell Lung Cancer Treatment

  • Common medications include cisplatin (Platinol- AQ), cyclophosphamide (Cytoxan), docetaxel (Taxotere), doxorubicin (Adriamycin, Rubex), etoposide (Vepesid), irinotecan (Camptosar), lurbinectedin (Zepzelca), paclitaxel (Onxol, Taxol), topotecan ( Hycamtin), and vincristine (Oncovin).
  • Combination chemotherapy with a cisplatin-containing regimen is the standard treatment for small-cell lung cancer. Treatment cycles are generally repeated every three weeks.  Four to six cycles of medication are provided to patients.
  • Radiotherapy for the chest should be started as soon as possible or given later in the treatment process. This is determined by factors such as the cancer's stage and the person's overall wellbeing.
  • Radiation and chemotherapy: Sequential radiation therapy, accompanied by chemotherapy, can be used. The earlier radiation is initiated simultaneously with chemotherapy (as early as the first step of chemotherapy), the better the outcome in comparative trials.
  • Radiation treatment to the patient's brain can be given if the patient has limited disease and has had a successful response to chemotherapy. This would minimise the chance of small-cell lung cancer progressing to the brain. Prophylactic cranial irradiation is the term for this (PCI). It's normally offered when the patient has finished both of their chemotherapy and radiotherapy treatments (to the thorax). Since the radiation doses are low and the care period is limited, the therapy's side effects are negligible.


Treatment for small-cell lung cancer in its advanced stages (small-cell lung cancer that remains incurable with current treatment options)

  • Combination chemotherapy is used to treat those with advanced-stage small-cell lung cancer. Currently, the most often employed regimen is cisplatin or carboplatin plus etoposide (PE).
  • The following symptoms can be controlled with radiation therapy:
    • Bone pain
    • Compression of the oesophagus, windpipe, spinal cord, or superior vena cava caused by tumors
    • Obstructive pneumonia caused by the tumor
  • The addition of atezolizumab or durvalumab to platinum (cisplatin or carboplatin) immunotherapy is indicated for patients with newly diagnosed extensive small-cell lung cancer.

Treatment of relapse of small-cell lung cancer

  • Relapsed small-cell lung cancer patients face an extremely poor prognosis.
  • Additional medication can help alleviate symptoms and prolong overall survival if the disease does not respond to treatment or persists after initial treatment (referred to as “refractory disease"). Immunotherapy may be considered. If immunotherapy is not an alternative, topotecan (Hycamtin)-based chemotherapy is usually used.
  • Additional chemotherapy, like re-treatment of their initial chemotherapy protocol, can be offered to people whose cancer has not progressed after more than three months.
  • Drug trials are available for those with relapsed or refractory small-cell lung cancer. Visit the National Cancer Institute's Clinical Research website for more details on current clinical trials.

Other medications can be used to manage and avoid side effects from radiation, chemotherapy, or the cancer itself, such as nausea and vomiting. Pain killers are often essential to alleviate the pain caused by cancer or its care.



Since nearly all tumours have advanced by the time they are detected, surgery has little, if any, part in the treatment of small-cell lung cancer.

The exceptions are the comparatively few patients (less than 15%) whose cancer is detected at an early stage of the illness, as it is limited to the lung and has not spread to the lymph nodes. Chemotherapy is offered in addition to surgery since surgery itself is not deemed curative. If the cancer has spread to the surrounding lymph nodes, radiation treatment might be needed.


Other Therapy

Radiation therapy

The application of high-dose X-rays or other high-energy rays to destroy cancer cells is regarded as radiation therapy. Radiation may be delivered by a machine from outside the body (external radiation therapy) or by the use of radiation-producing materials inserted within the body (internal radiation therapy) (brachytherapy).

Radiation treatment may be curative (kills all cancer cells), prophylactic (reduces the risk of cancer spreading to the region where it is given), or palliative (helps reduce suffering).


Next Steps

  • Chemotherapy patients must be closely monitored for adverse effects and reactions to the medication.
  • Prior to each cycle of chemotherapy, a blood examination, including an FBC (full blood count), is required to ensure that the bone marrow has recovered before the next dose of chemotherapy is administered.
  • The patient's kidney function is monitored, particularly whether he or she is taking cisplatin, which may harm the kidneys. Furthermore, carboplatin dose is determined by kidney function.
  • A CT scan will be performed on the patient to measure their response to therapy.
  • Due to the symptoms of the cancer and its treatment, other studies are conducted to monitor liver function and electrolytes, especially sodium and magnesium levels.


Palliative and terminal care

Since most patients are diagnosed with small-cell lung cancer when it is untreatable, palliative treatment becomes essential. Palliative and terminal treatment aim to relieve pain and anxiety while also improving quality of life.

Palliative care is concerned not only with the patient's comfort but also with the needs of the patient's families and loved ones. In addition to doctors, nurses, and other health care staff, caregivers can involve family and friends.

Palliative and end-of-life treatment is often offered in a hospital, hospice, or nursing home, although it may often be provided at home.


Lung Cancer Prevention

Unlike several other types of cancer, lung cancer has well-established risk factors. Since cigarette smoke is the main cause of lung cancer, stopping smoking is the most successful way to prevent lung cancer.

Nicotine gum, medicated nicotine sprays or inhalers, nicotine patches, and oral medications are also used to help you stop smoking. Furthermore, group therapy and behavioural training increase the likelihood of quitting.

Visit the following websites for guidance about how to stop smoking:

  • American Lung Association, Freedom From Smoking
  • Quitnet

Asbestos, radon, and plutonium toxicity are all contributing factors to lung cancer. Take steps to minimise or minimise the exposure to potentially dangerous compounds.


Small-Cell Lung Cancer Prognosis

Treatment progress is determined by the stage of small-cell lung cancer.

Unfortunately, by the time small-cell lung cancer is diagnosed, it has spread to other parts in the body in the majority of people. Life expectancy is shortened as a result of this. The five-year survival rate varies between 2% and 31%.

While patients with advanced small-cell lung cancer cannot be cured, medications are available to enhance the quality of life and treat the complications associated with the cancer or its treatment.


Support Groups and Counseling

Support groups and therapy will leave you feeling less alone and help you cope with the uncertainties and struggles that cancer presents.

Cancer support groups provide a platform for cancer patients, survivors, and both to share the problems that come with the diagnosis, as well as provide advice about how to cope with your questions.

Support groups enable people to discuss information about the illness, offer and receive guidance about how to manage side effects, and share emotions with those who are going through the same thing.

Family and friends can also benefit from support services that help them cope with the burden of cancer.

Many organisations have community groups for cancer patients and their families. Your doctor, nurse, or hospital social worker can provide you with information about such groups.


Referenced on 30.3.2021

  1. American Cancer Society.
  2. American College of Chest Physicians.
  3. University of Pittsburgh Medical Center.

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