Cancer Advances: Test Shows Promise In Detecting Early Lung Cancer
Lung cancer is rarely caught early, which is a big reason it kills more Americans than any other form of the disease; indeed, five-year survival rates hover around 15 percent. A study in this week's New England Journal of Medicine suggests that spiral computed tomography, or CT, which takes X-rays from many different angles and combines them into high-resolution images, is able to pick up small tumors early enough to cure patients. The test is controversial; the American Cancer Society, for example, doesn't yet endorse it, saying there aren't enough data to show that on the whole, CT screening actually saves lives.
Researchers led by Claudia Henschke, a radiologist at New York Presbyterian Hospital-Weill Medical College of Cornell University, report that most of the cancers they found by screening people without symptoms–but at high risk for the disease–were stage one, and in those patients, the estimated 10-year survival rate was 88 percent. That's about the same as the survival rate among early-stage breast cancer patients whose tumors were detected by mammography and then removed, they write. While previous research showed that the test could pick up smaller tumors, it wasn't clear that it would make a difference. "Now we have some information about that, and it's good," says Robert Young, president of Fox Chase Cancer Center in Philadelphia and chairman of the National Cancer Institute's Board of Scientific Advisors. "This is encouraging."
But this study isn't likely to alter current screening recommendations, says Young, since several issues remain. First, it's important to figure out how many people will undergo unnecessary lung biopsies or be treated for cancers that never would have progressed into serious disease. It's also crucial to define the group of people who will get the most benefit from screening, whether it be current or former heavy smokers, those with a family history of lung cancer, or people exposed to secondhand smoke. And researchers need to figure out the best way to follow up findings of the tiniest tumors: Watch and wait, or operate immediately?
Minds and recommendations aren't likely to change until the results of a large National Cancer Institute study come out toward the end of the decade. That study, unlike this one, is following two groups of people–those who are screened and those who aren't–and will look at how many in each group are alive at the end of the study. The bottom line, says Edward Patz, a radiologist at Duke University and a co-investigator in the NCI study, is "whether screening brings more benefit than harm." For that, he says, "we need more data." He says he's seen too many other tests and procedures, such as bone marrow transplants for breast cancer patients, adopted before there was evidence showing they, on balance, helped patients.
Some groups say the data so far are enough. The Lung Cancer Alliance, a patient advocacy group, recommends that certain groups of people (current or former heavy smokers over age 50 and adults who were both exposed to cigarette smoke and had a close relative diagnosed with lung cancer before age 50) should talk to their doctors about a CT scan. Henschke says the enormous number of deaths from lung cancer every year–more than 160,000, far more than other cancers that are already being screened for–means this test should be offered now. "There's considerable evidence that you can prevent deaths from lung cancer," she says. For now, until the results of the large NCI study come out, people will have to talk to their doctors and "make their own decisions on the basis of this information," says Young.
advertisement
