Cancer Current Topics in Cancer

Can CT Scans Prevent Lung Cancer Deaths?

While survival rates for some of the most common types of cancer have been on the rise, the percentage of lung cancer patients who survive for five years after their diagnosis is still quite low. In fact, lung cancer has been the number one cause of cancer deaths in the United States for many years.

But a new study shows that one tool may have the potential to change these statistics and drastically alter the way lung cancer is diagnosed and treated in the United States.

There will be 173,000 people diagnosed with lung cancer this year, and 164,000 who have lived with the disease will die from it, making the survival rate of lung cancer patients about 5 percent, according to Dr. Claudia Henschke, lead study author and chief of the chest imaging division at New York Presbyterian/Weill Cornell Medical Center.

The difficulty in lung cancer treatment lies in the fact that lung cancer often causes no symptoms until it has developed into a late-stage of the disease. At this point, the cancer has typically grown and spread to other parts of the body, beyond the point where modern treatments can really help.

Other forms of cancer, like breast cancer and colon cancer used to have low survival rates as well, until the development of screening methods, like mammography and colonoscopy, which are used to find cancerous cells at early stages of the disease—when it is most successfully treated.

Henschke believes that lung cancer should be no different. If lung cancer can be detected at its earliest stage, surgery can be used to remove the cancerous cells from the lungs and dramatically increase the patient’s chance of survival.

In the past, however, most scans were not sensitive enough to detect miniscule cancer cells on the surface of the lung before they grew into large masses. But, recently, one scan in particular has evolved into a much more sensitive tool for cancer detection.

The modern computed tomography (CT) scan can produce over 600 cross-sectional images of a patient’s chest in one pass, allowing doctors to get a much more complete view of a patient’s lungs than more primitive versions of the CT scan, which produced only 30 images. With this greater sensitivity, comes the use of CT scans to screen those people at highest risk to detect lung cancer early.

Currently, CT scans are sometimes prescribed by doctors for patients they believe are at risk for lung cancer, but no work has been done to monitor the impact these scans make in lung cancer diagnosis. Moreover, there are no set guidelines as to when CT scans are medically important to detect lung cancer, so some insurance companies do not cover the cost of the test.

So, to test the usefulness of CT scans in early lung cancer diagnosis, researchers from Henschke and colleagues from New York Presbyterian/Weill Cornell Medical Center looked at over 31,000 people who were at high risk for developing lung cancer because of a history of smoking or exposure to second-hand smoke or particular chemicals.

Using the sensitive CT scans, the doctors diagnosed 484 of the participants with lung cancer, 412 of whom had Stage I disease, an early form of lung cancer. Some patients decided not to be treated, but among those who did have surgery to remove the cancerous regions of their lungs 80 percent had survived at least 10 years after their initial diagnosis.

“We believe this study provides compelling evidence that CT screening for lung cancer offers new hope for millions of people at risk for this disease and could dramatically reverse lung cancer death rates,” said Henschke.

Henschke hopes that this study will encourage more people to seek screening for lung cancer. She recommends that anyone over the age of 50 who has smoked a pack a day for 10 years, or more packs a day for fewer years, talk with their doctor about being screened for lung cancer.

“The fact is, we can find lung cancer early,” said Henschke. “And when you take it out earlier you really can be cured.”