Diagnosis

Prevention still offers the greatest opportunity to fight lung cancer.

Although decades have passed since the link between smoking and lung cancers became clear, smoking is still responsible for most lung cancer deaths. Research is continuing on:

Ways to help people quit smoking and stay tobacco-free through counseling, nicotine replacement, and other medicines Ways to convince young people to never start smoking Inherited differences in genes that may make some people much more likely to get lung cancer if they smoke or are exposed to someone else’s smoke.

Researchers also continue to look into some of the other causes of lung cancer, such as exposure to radon and diesel exhaust. Finding new ways to limit these exposures could potentially save many more lives.

Researchers are looking for ways to use vitamins or medicines to help prevent lung cancer in people at high risk, but so far none have been shown clearly to reduce risk.

Some studies have suggested that a diet high in fruits and vegetables may offer some protection, but more research is needed to confirm this. While any protective effect of fruits and vegetables on lung cancer risk is likely to be much smaller than the increased risk from smoking, following the American Cancer Society dietary recommendations (such as staying at a healthy weight and eating a diet high in fruits, vegetables, and whole grains) may still be helpful.

Screening with spiral CT scans in people at high risk of lung cancer (due to smoking history) has been found to lower the risk of death from lung cancer, when compared to chest x-rays.

Another approach now being studied uses newer, sensitive tests to look for cancer cells in sputum samples. Researchers have found several changes often seen in the DNA of lung cancer cells. Studies are looking at tests that can spot these DNA changes to see if they can find lung cancers at an earlier stage.

There are many ways to perform a diagnosis. They include:

• X-rays
• CT scans
• Lab tests
• CT angiogram
• Biopsy
• Lung nodule analysis
• PET/CT scan
• Endobronchial ultrasound
• Lung nodule diagnosis

Two newer technologies are fluorescence bronchoscopy and virtual bronchoscopy.

Also known as autofluorescence bronchoscopy, this technique might help doctors find some lung cancers earlier, when they are likely to be easier to treat. For this test, the doctor inserts a bronchoscope through the mouth or nose and into the lungs. The end of the bronchoscope has a special fluorescent light on it, instead of a normal (white) light.

The fluorescent light causes abnormal areas in the airways to show up in a different color than healthy parts of the airway. Some of these areas might not be visible under white light, so the color difference can help doctors find these areas sooner. Some cancer centers now use this technique to look for early lung cancers, especially if there are no obvious tumors seen with normal bronchoscopy.

This imaging test uses a chest CT scan to create a detailed 3-dimensional picture of the airways in the lungs. The images can be seen as if the doctor were actually using a bronchoscope.

Virtual bronchoscopy has some possible advantages over standard bronchoscopy. First, it is non-invasive and doesn’t require anesthesia. It also helps doctors look at some airways that they might not be able to reach with standard bronchoscopy, such as those being blocked by a tumor. But this test has some drawbacks as well. For example, it doesn’t show color changes in the airways that might indicate a problem. It also doesn’t let a doctor take samples of suspicious areas like bronchoscopy does. Still, it may be a useful tool in some situations, such as in people who might be too sick to get a standard bronchoscopy.

This test will probably become more available as the technology improves.