LUNG CANCER

LUNG CANCER

More than 90,000 men and 79,000 women are diagnosed each year with cancer of the lungs and bronchi (the air tubes leading to the lungs). Among men, the incidence of lung cancer has been declining, but it continues to increase among women. The number of lung cancer deaths among women surpasses those from breast cancer.

Recent studies indicate that female smokers may be more likely to develop lung cancer than male smokers.

TYPES OF CANCERS

There are two major types of primary lung cancer: non-small cell and small cell. Each affects different types of cells in the lung and grow and spread in different ways, so doctors treat them differently. A diagnosis will include not only the type of lung cancer but the stage, which describes the extent and spread of the disease at diagnosis.

• Non-Small Cell Lung Cancer

Non-small cell lung cancer, the most common type of lung cancer, is usually associated with a history of smoking. The three main types of non-small cell lung cancer are named for the type of cell found in the tumor: squamous cell carcinoma (also called epidermoid carcinoma); adenocarcinoma; and large cell carcinoma. Non-small cell lung cancer is described using four stages: in stage I, the cancer is confined to the lung; in stages II and III, the cancer is confined to the chest; and in stage IV, the cancer has spread from the chest.

• Small Cell Lung Cancer

Small cell lung cancer (sometimes called oat cell lung cancer) accounts for approximately 20 percent of all lung cancer cases and is also associated with a history of smoking. The extent of the disease is described using a two-stage system. A case can either be limited, meaning the cancer is confined to a portion of the chest where it originated, or extensive, meaning the cancer has spread throughout or from the chest.

Mesothelioma, a rare cancer of the chest and abdominal lining, primarily affects persons who have had occupational exposure to asbestos particles.

Tumors found in the lungs sometimes originate from cancers elsewhere in the body. These tumors are called lung metastases.

RISK & PREVENTION

Smoking tobacco in any form is the major risk factor for lung cancer. Nonsmokers who breathe the smoke of others, often called secondhand smoke, are also at increased risk for lung cancer. Stopping exposure to tobacco smoke at any age lowers the risk of lung cancer.

Risk factors for lung cancer besides smoking include the following:

• Radon

An odourless radioactive gas produced naturally in rocks and soil, radon is found in homes and mines in some areas. Exposure to high indoor radon levels can cause damage to the lungs that may lead to cancer.

• Asbestos

If inhaled, asbestos particles can cause lung damage that may lead to lung cancer and mesothelioma (a rare cancer of the chest and abdominal lining).

Smoking Cessation

Not everyone who gets lung cancer has a history of smoking. If you do smoke, however, you can reduce your risk for lung cancer -- and the risk of those around you -- by stopping now.

DIAGNOSIS

Lung cancer is difficult to detect early because symptoms usually do not appear until the disease is advanced. Symptoms depend on the location of the tumor and can include persistent cough, hoarseness or wheezing, shortness of breath, sputum streaked with blood, recurring bronchitis or pneumonia, weight loss and loss of appetite, and chest pain.

Physicians use several techniques to diagnose lung cancer, including the following:

Imaging Tests

Chest x-rays, computed tomography (CT) scans, and magnetic resonance imaging (MRI) help locate abnormal areas in the lung.

Low-Dose Helical CT

A technique called low-dose helical (or spiral) CT may offer a novel approach for diagnosing lung cancer by exposing the patient to less radiation than a conventional chest CT scan while allowing the doctor to see areas of the chest normally obscured in a standard x-ray.

Bronchoscopy & Biopsies

A sputum sample can be analyzed for the presence of cancerous cells. Doctors may perform a bronchoscopy, which allows them to examine the bronchial passages using an instrument called a bronchoscope. This is a small tube that is inserted through the nose or mouth, down the throat and into the bronchi. During the procedure physicians may remove some tissue for analysis.

A modified form of bronchoscopy called autofluorescence bronchoscopy, which can detect early invasive cancers not seen with standard x-rays or white-light bronchoscopy, is being used to detect very early lung cancer.

To examine areas of the lungs that are not accessible during a bronchoscopy, physicians may perform a needle biopsy ("fine needle aspiration" or FNA) to remove a small sample of tissue for analysis.

TREATMENT

Depending on the type and stage of the disease, lung cancer can be treated with surgery, chemotherapy, radiation therapy, or a combination of these treatments.

Surgery

For non-small cell lung cancers that have not spread beyond the lung, surgery is most often used. Over the past several years, surgical techniques for treating lung cancer have improved greatly.

There are three surgical procedures commonly used to treat lung cancer:

wedge resection, or segmentectomy (in which a small section of the lung is removed)

lobectomy (in which an entire section is removed)

pneumonectomy (which involves the removal of an entire lung)

Minimally Invasive Surgery

Where appropriate, we offer minimally invasive surgical procedures, including video-assisted thoracic surgery (VATS), or thoracoscopy. VATS allows the surgeon to operate with roboting assistance by inserting an illuminated tube through a small incision into the lung through the ribs. Because the incisions are much smaller than with an open operation, post-operative healing time and pain are reduced.

Chemotherapy

For patients whose tumors are somewhat more advanced, a program of chemotherapy before surgery increases the cure rate. In some cases, the cancer is completely eliminated with chemotherapy before the patient has even had surgery.

Even if the surgeon removes the entire tumor that can be seen, adjuvant chemotherapy may be offered to kill cancer cells that may still be present in nearby tissues or elsewhere in the body. For small cell lung cancer in particular, chemotherapy, often combined with radiation therapy, is now the most common treatment.

Radiation Therapy

When surgery is not the best option, our radiation therapy system permits the delivery of the highest possible radiation dose targeted precisely to the tumor. This method spares normal tissues and lessens damage to other organs in the chest. Radiation therapy is also sometimes used to relieve pain and bleeding and alleviate problems with swallowing.

Both 3-D conformal radiation therapy and intensity modulated radiation therapy (IMRT) allow doctors to change the shape and intensity of radiation beams so they are focused more effectively on cancer cells and away from the surrounding tissue and organs.

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