Squamous cell carcinoma of the lungs is one form of non-small cell lung cancer. Non-small cell lung cancers account for about 80% of lung cancers, and of these, roughly 30% are squamous cell carcinomas.
Squamous Cell Carcinoma of the Lungs – An Overview
Squamous cell carcinoma begins in the tissue that lines the air passages in the lungs. It is also known as epidermoid carcinoma. Most squamous cell carcinomas of the lungs are located centrally, usually in the larger bronchi that join the trachea to the lung. Squamous cell carcinomas are linked more strongly with smoking than other forms of non-small cell lung cancers, and are more common in men than in women. They tend to be slow-growing, and due to their location are often found earlier than other forms of lung cancer.The incidence of squamous cell carcinoma of the lungs has been decreasing in recent years, whereas another form of lung cancer, adenocarcinoma has been increasing. It is thought by some that the addition of filters to cigarettes allows smoke to be inhaled more deeply into the lungs where adenocarcinomas tend to occur.
Squamous Cell Carcinoma of the Lungs - Symptoms
Common symptoms of lung cancer include a persistent cough, coughing up blood, and wheezing. Since squamous cell carcinomas tend to be located near the large airways, they often cause symptoms earlier than other forms of lung cancer. Obstruction of the airway can lead to infections such as pneumonia, or collapse of part of a lung (atelectasis).Squamous cell carcinoma is the most common cause of something known as pancoast syndrome or superior sulcus syndrome. Pancoast syndrome is caused by lung cancers that begin near the top of the lungs and invade structures nearby. Symptoms often include shoulder pain that radiates down the inside of the arm, weakness or prickly sensations in the hands, flushing or sweating on one side of the face, and a droopy eyelid (Horner’s syndrome).
Individuals with squamous cell carcinoma are also more likely to experience an elevated calcium level (hypercalcemia) which can result in muscle weakness and cramps. Hypercalcemia is one of the symptoms of paraneoplastic syndrome, and is caused by a tumor secreting a hormone-like substance that raises the calcium level in the blood.
Squamous Cell Carcinoma of the Lungs - Diagnosis
Squamous cell carcinoma of the lungs is often first suspected when abnormalities are seen on an x-ray. Further evaluation may include:- Chest CT Scan
- Sputum Cytology – Since squamous cell carcinomas often extend into the airway, a sample of sputum can sometimes detect cancer cells
- Bronchoscopy
- PET Scan - a test designed to look for actively growing tumors
- Endobronchial Ultrasound
Depending upon the results, your doctor will usually want to obtain a sample of tissue to confirm the diagnosis, and will order further tests to check to see if your cancer has spread.
Squamous Cell Carcinoma of the Lungs - Staging
Squamous cell carcinoma of the lungs is broken down into 4 stages:- Stage 1 – The cancer is localized within the lung and has not spread to any lymph nodes
- Stage 2 – The cancer has spread to lymph nodes or the lining of the lungs, or is in a certain area of the main bronchus
- Stage 3 – The cancer has spread to tissue near the lungs
- Stage 4 – The cancer has spread (metastasized) to another part of the body
Squamous Cell Carcinoma of the Lungs - Causes
Squamous cell carcinoma of the lung is strongly associated with smoking, but other causes can contribute as well.Squamous Cell Carcinoma of the Lungs - Treatments
Depending upon the stage of squamous cell carcinoma of the lungs, treatment may include surgery, chemotherapy, radiation therapy, or a combination of these. Many clinical trials are in progress looking for new ways to treat this cancer, and to help decide which treatments are most effective.Surgery
When lung cancer is caught in the early stages, surgery may offer a chance to cure the disease.Chemotherapy
Chemotherapy may be used alone, in conjunction with radiation therapy, or following surgery for lung cancer. Squamous cell carcinoma of the lungs responds somewhat differently than other lung cancers such as adenocarcinoma to chemotherapy medications. Common medications used initially with this type of cancer include cisplatin (Platinol) and gemcitabine (Gemzar). For those who respond to treatment, continuous (maintenance treatment) with erlotinib (Tarceva) may be used.Radiation Therapy
Radiation therapy may be used to treat cancer, or to control symptoms related to the spread of cancer. Radiation may be given externally, or internally (brachytherapy) in which radioactive material is delivered to a precise area of the lungs during a bronchoscopy.
Squamous Cell Carcinoma of the Lungs – Prognosis
The overall 5-year survival rate for lung cancer is sadly only about 15%. For early-stage disease, especially when surgery can remove the tumor, the survival rate is much higher.Squamous Cell Carcinoma of the Lungs – Coping
A diagnosis of squamous cell carcinoma of the lungs is frightening and you may feel very alone. Allow your loved ones to support you. Many people have no idea how to react towards someone who is diagnosed with cancer. Letting people know specific things they can do to help may ease their anxiety, as well as fill your need for extra support at this time. Ask questions. Consider joining a lung cancer support group either through your cancer center or online. Talking with others who have “been there” can make the world seem a little smaller.Sources:
College of American Pathologists. Lung: Squamous Cell Carcinoma. Accessed 06/22/10. http://www.cap.org/apps/docs/reference/myBiopsy/lung_squamous_cell_carcinoma.html
Sheth, S. Current and emerging therapies for patients with advanced non-small cell lung cancer. American Journal of Health-System Pharmacy. 2010. 67(1 Suppl 1):S9-14.
Yasufuku, K. Early diagnosis of lung cancer. Clinics in Chest Medicine. 2010. 31(1):39-47.
