UCSF Medical Center Offers Early Screening for Lung Cancer

August 01, 2000
News Office: Leslie Harris (415) 885-7277

UCSF Medical Center is offering a screening for early detection of lung cancer, a disease that claims about 157,000 lives in the United States each year - more than breast, prostate and colon cancer combined.

Using spiral computerized tomography (CT) scanning, physicians are able to detect tiny nodules on the lungs that could be lung cancer in its earliest stages. This technology may help reduce the number of lung cancer deaths by allowing physicians to catch the disease early and surgically remove lesions before they grow and spread through the body, said Dr. Paul Brunetta, a pulmonologist at UCSF Medical Center and a UCSF assistant professor of pulmonary medicine.

Brunetta began offering CT scans, also called CAT scans, to patients two months ago in the Thoracic Oncology program at UCSF Medical Center at Mount Zion.

"I think we need to be as hopeful about this technology as we were about mammography," Brunetta said. "I think we can identify people at risk for lung cancer."

CT scans use X-rays to scan the entire chest in about 15 to 20 seconds during a single breath hold. The patient lies on a table, passing through an X-ray machine shaped like a doughnut with a large hole. The machine rotates around the patient as a computer creates images from the scan.

If the radiologist detects an abnormal looking nodule, he or she recommends a higher resolution scan to see if the small mass has characteristics of cancer. If the nodule is still potentially malignant, the patient either has a repeat scan in three months or a biopsy of the mass is performed (a section of the tissue is removed to determine if it is cancer).

Lung cancer is the leading cause of cancer deaths in the United States, accounting for nearly 28 percent of all cancer deaths, according to the American Cancer Society. Unlike breast, prostate and other cancers, there are no tools to diagnose lung cancer early. Usually, 90 percent of all lung cancers are detected when patients show symptoms of the disease, such as coughing blood or chest pain. By then, the disease may have spread to other parts of the body, making it difficult for physicians to save the patient's life, Brunetta said. More than 80 percent of all lung cancer cases are related to smoking.

Physicians across the country are debating the effectiveness of using CT scans for early detection for lung cancer. CT scans have not been shown to decrease lung cancer mortality rates. Previous studies have estimated that of all nodules detected with this technology, just 15 percent are malignant. What can appear to be the beginnings of a tumor are often harmless marks on the lungs caused by dust or scars left from other illnesses such as pneumonia. This raises concerns about the tests creating false/positive results that can potentially cause patients to undergo unneeded biopsies.

"As long as it hasn't been proven effective, people say why are you doing this?" Brunetta said. "It has a high cost and you run the risk of performing unnecessary biopsies, as would be the case with an abnormal mammogram." But Brunetta believes the tests could be an important tool in fighting lung cancer, which has a five-year survival rate of only 13 percent.

"Lung cancer is a very common and deadly disease. The way we treat it now is dismal," Brunetta said. "If we are finding that in the majority of patients we can't cure the disease, then where does that leave us? The technology is widely available. It only requires that people hold their breath for 20 seconds. And it's not painful or invasive. If we can detect the disease early enough to have a 90 percent resectability rate (surgically removing the tumor), then I think it's worthwhile. We need to study this carefully."

Brunetta is principal investigator of the Early Lung Malignancy Study, which will examine lung cancer detection rates among high risk individuals using CT scanning and sputum tests - when phlegm coughed from the patient's lungs is inspected for signs of cancer. To enroll, participants must be age 60 or older and have a 20-pack-year or greater history of cigarette smoking. A pack year is the number of years someone has smoked multiplied by the number of packs smoked per day. Someone with a 20-pack-year history could have smoked one pack of cigarettes for 20 years or two packs per day for 10 years.

Participants also must have one or more other risk factors, including asbestos exposure, a family history of cancer, prior obstructive lung disease, prior lung or head and neck cancer or significant exposure to radioactivity.

CT scans have been used since the 1970s to provide diagnostic information for many parts of the body, including the brain, blood vessels, heart, liver and skeletal system. For cancer, CT scanning is used to determine how much a tumor has grown after the initial diagnosis, according to the National Cancer Institute. More than half of the hospitals in the United States have a CT machine. Only recently have some hospitals and practices begun offering CT scans to patients for early detection of lung cancer.

"We know anecdotally that this can save lives," said Dr. Ron Arenson, chair of the radiology department at UCSF Medical Center and a UCSF professor of radiology. "The question is can we justify the cost of massive screening. Chasing down all of those false positives can be an enormous expense. But it's not as much when you compare it to the cost of taking care of cancer patients."

Brunetta added: "Early detection of cancer can potentially save lives, as has been proven with breast cancer," he said. "This remains unproven, however, with this promising imaging technique."

For more information regarding the study, please call (415) 885-7387.

For more information about CT scans, please call (415) 885-7282 or call (415) 885-7465 to schedule a screening.