As radiology prepares to embark on yet another screening endeavor, there is no time like the present to reflect on the land mines inherent in the screening of large segments of the population for the early detection of cancer—particularly in light of the current controversies in mammography. Because the United States Preventive Services Task Force (USPSTF) gave lung-cancer screening with low-dose CT (LDCT) for high-risk patients a grade B recommendation (and coverage by private insurers is virtually ensured), radiology could find itself engaged in three screening initiatives: for breast cancer, lung cancer, and (to a lesser extent) colon cancer.
This would give a specialty with scant patient contact a significant role in the management of population health. As radiology awaits the results of Medicare’s National Coverage Analysis of LDCT lung-cancer screening, however, mammography sits squarely in the crossfire of conflicting studies regarding its usefulness (see article).
The conclusions of these studies have ranged from the extreme (mammography plays an insignificant role in reducing morbidity and mortality from breast cancer) to potentially life threatening. The operative word is potentially: We don’t know how many more women would die of breast cancer if screening starts at age 50 (instead of 40), nor do we know how many more would die if we initiated biennial (rather than annual) screening.
Another question that no one can answer with any degree of certainty is the age at which women should stop getting mammograms. Is breast cancer in older women less virulent? There also are the societal questions: Is an older life worth the protection accorded a younger one? When my 84–year-old mother asks me if she really needs to get a mammogram, I reply as any prudent person who doesn’t know would reply: Yes, get a mammogram (if you can still ride a bicycle).
Because breast-cancer screening casts such a wide net, every time a new study is published, it gets copious ink and airtime. Screening is only as effective as patients are compliant, so the net effect of women thinking that they don’t need to get annual mammograms is a less-effective screening program.
How is radiology to respond? Throughout the firestorm, the specialty has not wavered in its support of mammography, standing firm with the American Cancer Society in recommending annual screening for all women, beginning at age 40. Neither has it stood idly by without working to make screening more effective: In 2005, the results of the Digital Mammographic Imaging Screening Trial1 were published.
Currently, the ACR® Imaging Network lists three open breast-imaging trials, two published closed trials, another for which publication is in process, and two more soon to open. How, then, has the specialty found itself on the defensive when it comes to mammography? Shortly after the USPSTF gave lung-cancer screening with LDCT in high-risk populations a B grade, no less than 40 medical organizations joined the ACR in urging Medicare to approve coverage for the screening procedure. Didn’t mammography once entertain that same level of support? What can the specialty do to retain that support?
Consider one of the same questions that CMS is asking right now: Who should perform the study? The criteria need to be stringent enough to exclude those who are not competent, but inclusive enough to ensure patient access in every community. I would submit that over time, these criteria become more restrictive as more people gain more expertise, and the gap between competence and expertise grows. That has not happened in mammography.
Many of the radiologists with the most experience in screening for lung cancer with LDCT would agree that almost every aspect of the process is a moving target, from whom to screen to what to look for and which lesions to biopsy (see article, page 24). Educating the radiology community about the evolving standard of care will be a big job.
While there is an important and very effective patient-advocacy organization for lung-cancer patients in the Lung Cancer Alliance, it does not have the clout of the breast-cancer lobby (I’m not sure that even the oil industry has that much clout). Engaging and tracking patients so that they return each year are the greatest challenges that radiology will face in implementing a successful screening program, and it can’t do those things alone.
As radiology prepares to assume responsibility for its role in LDCT lung-cancer screening, it should remember that it doesn’t own lung-cancer screening—any more than it owns mammography. All of medicine has a stake. Until cigarette smoking is history, engaging referrers in this endeavor will be key to the successful screening of the high-risk population—and to maintaining the support necessary for success.
- Pisano ED, Gatsonis CA, Yaffe MJ, et al. American College of Radiology Imaging Network Digital Mammographic Imaging Screening Trial: objectives and methodology. Radiology. Accessed April 14, 2014.