Small cell lung cancer accounts for about a 20% of all lung cancer cases. Also called oat cell carcinoma of the lung, it has the most rapid clinical course of any type of lung cancer, with average survival time of only several months without treatment. Compared with other types of lung cancer, small cell carcinoma has a greater tendency to have spread widely by the time of diagnosis and the majority of diagnosed patients also have metastases (spread of tumor to other organs/sites).
Because of its rapid growth, it tends to be more responsive to treatment with chemotherapy and radiation than are the other types of lung cancer.
Types There are several types of small cell lung cancer, defined by the tumor's appearance under the microscope. These include small cell, mixed small cell/large cell and combined small cell. It is unclear whether these types of tumor have different prognoses.
This tumor arises from neuroendocrine cells which produce hormones; under the electron microscope, hormone producing granules can be seen. These tumors, therefore, can produce an abnormal abundance of hormones which leads to their respective adverse effects.
How It Spreads Small cell lung cancer can spread via lymphatic vessels to the lymph nodes in the center of the lung, the center of the chest, in the neck and above the collarbone, and in the abdominal cavity. It is likely to spread through the bloodstream to the liver, lungs, brain and bone. Classically, small cell lung cancer presents with small primary tumors in the lung and enlarged lymph nodes.
- Cigarette smokers.
- Exposure to industrial substances such as asbestos, nickel, chromium, cadmium, uranium, radon compounds and chloromethyl ether, and/or air pollutants.
Staging The detailed staging techniques and classifications used for non-small cell lung cancer are not commonly used for small cell lung cancer. Instead, the staging system focuses on whether disease is limited or extensive. The stage of the tumor (limited versus extensive) will determine the prognosis and may affect the choice of treatment.
|Stage||Signs and Symptoms||Diagnostic Tests||Treatments||Survival|
Tumor is small and confined to the chest including mediastinum and supraclavicular lymph nodes. There is no pleural effusion (fluid around the lung).
New or changing cough, sometimes with blood
Lung cancer is difficult to diagnose at an early stage; only 1/3 of patients with small cell are identified early on
Blood tests: chemistry profile; examination of sputum or fluid from chest for presence of malignant cells
Imaging: chest x-ray; CT scan, MRI; spiral CT scanning has been developed to identify early stage lung cancer in at risk populations
Biopsy: of mediastimum, lymph nodes, chest lining
Microscopy: once cells are collected, pathologists can use this to accurately diagnose small cell lung cancer
Combination chemotherapy: multiple drugs are much more effective than single-agent
Radiation therapy: given at the same time as chemotherapy, this may improve survival rate Surgery: A small % of patients with very early stage disease may benefit
2 year: 20%
Tumor is wide-spread and cannot be confined to the chest
The above signs and symptoms. If tumor has metastasized, these can include:
The above exams plus those to evaluate presence of metastases
Scans: CT of abdomen; MRI or CT of brain; PET scans of mediastinum; bone scan
Endoscopy/biopsy: fiber-optic bronchoscopy with brushings or biopsy; biopsy of bone, lymph nodes or liver
Combination chemotherapy: Different combinations may be more effective than others
Radiation therapy: this may help relieve symptoms or with metastatic disease (brain, bone) but it is not necessary to the chest
2 year: 5%
If small cell lung cancer recurs, the prognosis is very poor regardless of stage or treatment
Any of the above plus others
Palliative therapy: pain relief and orthopedic aids
Investigational drugs/ clinical trials
- Supportive Therapy The importance of supportive therapy in the treatment of lung cancer cannot be overemphasized.
- Quite clearly, malnutrition results in a bad outcome in patients with lung cancer. Patients must be served a palatable meal and attempts must be made to work with patients to determine food likes and dislikes.
Pain control is of critical importance, and the tools to achieve control are available even for the most advanced cases. These include the use of pain-relieving (analgesic) drugs such as non-steroidal anti-inflammatory agents, mild narcotics, strong narcotics, continuous narcotics and narcotics delivered into the spinal canal (epidural). Pain control can generally be achieved without interfering with mental competence. Nausea can be controlled with a variety of drugs
Physical therapy will help maintain muscle strength to keep life as normal as possible.