(First, please note that this is a version of an original Chicago Tribune story as published by the Houston Chronicle. We were reviewing the Houston paper on this particular day, not the Chicago paper. The original version ran 1,244 words; the Houston version less than half that, at 572 words. This happens often, as we've commented on.)
Lung cancer is responsible for more deaths in the U.S. than any other type of cancer. It would be difficult to underestimate its importance. But the value of early detection remains open to debate. The news article covering the recent study on CT screening for early lung cancer in high-risk individuals highlights the main problem with the study—the absence of a comparison group. It hints that extended survival may be a mirage reflecting only an earlier diagnosis, rather than longer life, and rightly asks, “Does screening, in the end, save lives?” It also notes that better information from a huge randomized trial of nearly 55,000 participants may offer better information in the future. But the story trips up when it attempts to quantify the potential benefits of screening. And it passes up an opportunity to flesh out the debate on over-diagnosis and potential harms. According to the National Cancer Institute, anywhere from 25% to 60% of CT scans of high-risk individuals will detect an abnormality that is later discovered to be benign—causing a lot of trepidation among those undergoing the lung cancer screen. The biopsies prompted by positive scans also pose substantial hazards—partial lung collapse, bleeding, infection, pain, and even death. (See http://www.cancer.gov/cancertopics/factsheet/lung-spiral-CTscan.) With hospitals and others now marketing the scans at prices ranging from $200 to $1000, more education about its limitations would have been helpful.
In addition, the final paragraph of the article overstates the current evidence on the curability of early stage cancer. Whether aggressive treatment of Stage I cancer leads to a cure has yet to be determined, and is at the heart of the current controversy. It will remain theoretical until there is better data from randomized controlled trials.
The article does not mention costs of lung cancer screening with CT scans. According to various estimates, these can range from less than $200 to as much as $1000.
The article attempts to quantify survival rates with and without screening, but seems to trip up along the way. It states that the NEJM study estimated that “at least 88%” of patients diagnosed with early cancer “would survive for 10 years after the tumor was surgically removed.” It follows this by noting that 10-year survival among these patients is “usually about 70%” However, the study’s authors say that among patients with early stage cancer the 10-year survival rate “was 92%.” Ten-year survival was 88% in all patients diagnosed with early lung cancer, regardless of treatment–i.e., including chemotherapy, radiation, etc. (The article later corrects this.) In addition, the article’s statement that 10-year survival among these patients is “usually about 70%” is at odds with data presented in both the study and an editorial accompanying the NEJM study. Editorialist Michael Unger, MD, notes that about 70% of these patients are surviving at five years, not 10. The study’s authors cite higher survival rates in registry-based reports.
In addition, the final paragraph of the article overstates the current evidence on the curability of early stage cancer. Whether aggressive treatment of Stage I cancer leads to a cure has yet to be determined, and is at the heart of the current controversy. A “cure” will remain theoretical until we have better data from randomized controlled trials.
The article does not mention several potential harms of CT screening in high-risk individuals. These range from radiation exposure to needless anxiety after receiving a potentially false positive result to significant medical complications associated with biopsies.
The article points out the major limitation of the NEJM study—that it lacked a comparison group and thus was unable to determine whether screening actually saves lives. It also points out that a randomized trial under way at the National Cancer Institute will contribute more information in the future.
The article refrains from disease mongering. Lung cancer kills more people in the U.S. than any other cancer—some 162,000 in 2006, according to NCI estimates. Almost all who suffer with the disease are smokers or former smokers.
The article cites a single researcher not associated with the study, and provides his credentials. It also cites several organizations who remain skeptical about CT screening, though additional sources would have helped to flesh out the debate.
The story notes that the alternative to early CT screening for high-risk individuals is no screening. But it could have devoted more space to explaining the disadvantages associated with CT screening, including its potential harms. (See "Harms of Treatment" above.)
The article does not describe the availability of CT screening for early lung cancer. According to the National Cancer Institute (NCI), 60% of hospitals have machines capable of performing lung CTs, usually to stage cancer after it has already been diagnosed. But hospitals and private diagnostic centers are now beginning to market CT screening for early disease.
The opening sentence of the article suggests that this is a relatively new use of CT technology. However, researchers have investigated the use of CTs for lung cancer screening for years, and the studies—including this latest one–remain controversial. The article does not attempt to put the new findings into the context of previous scientific studies on this topic.
There was no obvious use of material from a press release, and it used several sources.