What is Small Cell Lung Cancer?
Small Cell Lung Cancer (SCLC) is one of the major types of lung cancer and accounts for about 10 to 15% percent of all lung cancers. Small cell lung cancer is also referred to as oat cell carcinoma, oat cell cancer and small cell undifferentiated carcinoma.
Small cell lung cancer is an extremely aggressive type of lung cancer where the growth of the cancer cells is very fast and metastasizes easily to other parts of the body. Due to this, small cell lung cancer often gets diagnosed after the cancer has metastasized all over the body, which results in a poor prognosis. In patients where small cell lung cancer is detected early, treatment can also be started early before the cancer has reached the advanced stage which increases the chances of a better outcome.
What are the Causes of Small Cell Lung Cancer?
The exact cause of lung cancer or any other cancer is not known. It is thought that precancerous changes in the lungs affect the DNA of the lung cells leading to rapid growth of the lung cells and eventually resulting in lung cancer. Drastic changes in the cells can make them cancerous. The cancer cells are also fed by blood vessels, which cause them to grow rapidly and form tumors. As the time passes, the cancer cells can break away from the primary tumor and metastasize to other parts of the body.
What are the Risk Factors of Small Cell Lung Cancer?
- Smokers are at the highest risk for developing Small Cell Lung Cancer. Nonsmokers rarely develop Small Cell Lung Cancer. The risk for developing Small Cell Lung Cancer is directly proportionate to the number of cigarettes and the years of smoking done by the patient.
- Smoking pipes and cigars is equally dangerous and increases the risk for lung cancer.
- It's a myth that smoking "light" or low-tar cigarettes lowers the risk for developing lung cancer. In fact, menthol cigarettes can further increase the risk of lung cancer, because with menthol, there is deeper inhalation of the cigarette smoke.
- Exposure to secondhand smoke also increases the risk for lung cancer.
- There are certain substances in the environment, which if in regular contact with a person, increases the risk for lung cancer. These carcinogens include: asbestos, radon, uranium, inhaled chemicals (silica, arsenic, coal products), drinking water contaminated with arsenic, outdoor air pollution, diesel exhaust and some dietary supplements, such as beta carotene.
- Studies are going on to find out if the use of talcum powder and marijuana increases the risk of developing lung cancer.
What are the Symptoms of Small Cell Lung Cancer?
Small Cell Lung Cancer usually doesn't cause symptoms and is often asymptomatic. After the symptoms have appeared, it usually is an indication that the cancer has infiltrated to other parts of the body. As there is increase in the growth and spread of the cancer, the severity of symptoms also increases. Common symptoms of Small Cell Lung Cancer include:
- Shortness of breath.
- Production of bloody mucus from the lungs.
- Pain or discomfort in the chest.
- Hoarseness of voice or persistent cough.
- Loss of appetite.
- Weight loss.
- Facial swelling.
How is Small Cell Lung Cancer Diagnosed?
Patient's medical history and physical examination is done. Patient should inform the doctor whether he/she is a smoker. Different types of tests are done to diagnose Small Cell Lung Cancer and after the diagnosis is confirmed the staging of the lung cancer is done.
As mentioned before, the symptoms of Small Cell Lung Cancer are not apparent until it's too late. That is, the cancer has already reached an advanced stage by the time the symptoms surface. However, in some patients, Small Cell Lung Cancer is detected early during diagnostic testing which is done for a different medical condition. Some of the tests done for diagnosis of Small Cell Lung Cancer are: Chest x-ray, CT scan, MRI scan, bronchoscopy, sputum culture, complete blood count (CBC), lung needle biopsy and a bone scan to look for bone cancer.
How is the Staging of Small Cell Lung Cancer Done?
Staging of lung cancer or any other cancer helps in describing the extent or severity of the cancer and is also very helpful in determining the treatment options for the patient and in predicting the prognosis of Small Cell Lung Cancer.
The staging of Small Cell Lung Cancer is done in two stages:
Limited Stage of Small Cell Lung Cancer: In this stage, the cancer is limited to only one side of the chest. There may or may not be involvement of the lymph nodes.
Extensive Stage of Small Cell Lung Cancer: In this stage, the cancer spreads to the other side of the chest and involves the other lung also. The lymph nodes are also involved and the cancer has also spread to other parts of the patient's body.
If there are cancer cells present in the fluid surrounding the lungs, then also the stage of Small Cell Lung Cancer is considered to be Extensive. The prognosis of extensive stage of Small Cell Lung Cancer is not good as the cancer is not curable at this stage.
How is Small Cell Lung Cancer Treated?
It is important that appropriate treatment is started immediately after the diagnosis of Small Cell Lung Cancer has been confirmed. Immediate treatment is paramount for favorable outcome. However, if the Small Cell Lung Cancer is at an advanced stage, then treatment is not effective and the aim of treatment at this point is to manage and relieve the patient's symptoms and to make the patient's life as comfortable as possible. Treatment options for Small Cell Lung Cancer are:
Surgery: Surgery is done in Small Cell Lung Cancer only if there is one tumor present and if the cancer cells haven't spread to other parts of the body. However, this occurs rarely as majority of the times Small Cell Lung Cancer is diagnosed when it is at an advanced stage, so surgery is not usually beneficial. If surgery is an option for the patient, then the following surgeries are done for Small Cell Lung Cancer:
Lobectomy: This is a surgical procedure where the entire section or lobe of the lung is removed.
Segmentectomy: This is a surgical procedure where a segment of a lung lobe is removed.
Pneumectomy: In this surgical procedure, the entire lung is removed.
Sleeve Resection: In this surgical procedure, a section of the airway is removed and the lung is reattached.
All the above surgeries for Small Cell Lung Cancer are performed under general anesthesia. Lobectomy is the surgery of choice for Small Cell Lung Cancer as it is more effective in removing all the cancer when compared to other types of surgery.
Outcome & Recovery Period of Surgery for Small Cell Lung Cancer
The outcome of surgery for Small Cell Lung Cancer depends on the patient's general health before the surgery. The risks of surgery include infection, heavy bleeding and pneumonia.
If the surgery for Small Cell Lung Cancer is successful, then the recovery period can take anywhere from several weeks to several months. The patient will need complete rest for at least a month.
Chemotherapy: Chemotherapy is an aggressive type of drug therapy where special medications are given orally or intravenously to kill the cancer cells. Chemotherapy is effective in killing the cancer cells; however, it has serious side effects which affect the patient's quality of life. Some of the side effects of chemotherapy are: nausea, vomiting, diarrhea, fatigue, loss of appetite, extensive hair loss, mouth sores, dry mouth and pain due to nerve damage.
Radiation Therapy: Radiation therapy is a cancer treatment where concentrated radiation beams are used to kill cancer cells. External beam radiation is the most common type of radiation therapy. A machine is used which directs high-energy radiation beams at cancer cells to destroy them. The radiation can be targeted at specific sites. Radiation therapy can also be used in combination with chemotherapy to alleviate pain and symptoms of Small Cell Lung Cancer. Radiation therapy also carries side effects; however, most of them subside in a couple of months after the treatment.
What is the Prognosis & Survival Rate for Patients with Small Cell Lung Cancer?
Small Cell Lung Cancer is an extremely aggressive type of lung cancer which tends to remain undiagnosed until it has reached an advanced stage. Because of this, the survival rate is on the low side and the prognosis is poor. However, if Small Cell Lung Cancer is detected in its early stages, then the chances of recovery are higher which makes the survival rate and prognosis better.
Brief Summary About Small Cell Lung Cancer
- Small Cell Lung Cancer (SCLC) is one of the two types of lung cancers. The other type is non-small cell lung cancer (NSCLC).
- Small cell lung cancer is very aggressive and accounts for about 10 to 15 % of all cases of lung cancers.
- Smoking is the biggest risk factor for developing Small Cell Lung Cancer.
- Small cell lung cancer is often asymptomatic due to which it is often diagnosed when it is at its advanced stage.
- The treatment of small cell lung cancer consists of surgery, chemotherapy and radiation therapy.
- Early diagnosis and treatment of small cell lung cancer increases the likelihood of a good prognosis; otherwise the survival rate for small cell lung cancer tends to be low.