Are community physicians being careless or cautious when it comes to referring high-risk patients for low-dose computed tomography (LDCT) lung cancer screening?
A recent study found that community physicians are reluctant to refer patients for LDCT, despite evidence showing that this screening reduces lung cancer mortality by 20 percent when compared to a chest X-ray in patients with a history of heavy smoking and other risk factors.
This finding prompted the study’s author, Jennifer L. Ersek, MSPH, from the University of South Carolina to call this is an example of the “vexing challenge” in the U.S. healthcare system of translating new knowledge into clinical practice, which is where the majority of screening and prevention occurs.
But Dr. Mohsen Davoudi says that community physicians are probably being cautious, rather than careless.
“This is new, and doctors don’t want to subject their patients to a less-than-perfect screening protocol. The development of such guidelines is often an iterative process; they are usually modified and improved over time,” Davoudi says.
“Community physicians don’t want to miss lung cancer in their patients, but they also want to be sure each patient they are referring for screening benefits from this, has imaging and, if necessary, procedures that gives them a survival advantage.”
Another issue, Davoudi explains, is that screening is only the first step. The National Comprehensive Cancer Network recommends that only those centers that provide a comprehensive range of care, which includes minimally invasive sampling procedures, should administer the LDCT scans.
“Lung cancer is often not easy to diagnose, while doing a LDCT is easy. It is very important to emphasize that LDCT screening should only be done at the proper place, which is at a center that offers the state-of-the-art technology, advanced expertise and an established program to screen, diagnose and treat every patient effectively,” Davoudi says.
Lung screening evidence
LDCT screenings received a “B” grade from the U.S. Preventive Services Task Force (USPSTF), and are included in the Centers for Medicare & Medicaid Services preventive screening benefits. However, the American Academy of Family Physicians says there is insufficient evidence to support or discourage LDCT screening in patients at high risk for lung cancer.
The USPSTF is a group of health experts who review published research and make recommendations on preventive healthcare treatments. The “B” grade means that under the Affordable Care Act, private insurance must cover LDCT screening, and is based on results from the largest and best clinical trial, which showed fewer lung cancer deaths and deaths from any cause in adults who:
- Are aged 55 to 80 years.
- Have no lung cancer symptoms.
- Have at least a 30 pack-year history of smoking. Pack years measure the amount a person has smoked over a long period of time. One pack-year equals smoking one pack per day per year, or two packs per day for six months, and so on.
- Have received a counseling and shared-decision making visit before the screening.
Concerns about new technology
Research has demonstrated that early stage detection increases lung cancer treatment options and improves survival rates.
The goal of lung cancer screening is to find the lesion before it’s at the point where it’s not curable. Chest X-rays are not powerful enough to detect early stage lesions, and radiation exposure from repeated high-dose CT scans is not safe. The LDCT is meant to have the high resolution necessary to find tiny, early cancerous lesions, without the high risk of radiation from a standard high-dose CT.
Specific concerns cited by community physicians include:
- Radiation exposure.
- Overdiagnosis — finding and treating cases of cancer that may never have caused a problem for the patient.
- False-positive results — the test finds lesions suspected of being cancerous, which are not.
“Over-diagnosis and false-positive results are especially troubling because they can lead to additional worry, tests and surgery that turn out to be unnecessary,” Davoudi says. “This is probably the most common reason doctors may hesitate to refer their patients for screening. And this is why, I believe, it is crucial to screen the right patient population, those who meet the high-risk criteria.”
Keys to widespread acceptance
The key to more widespread acceptance of LDCT as a standard of care for lung cancer screening is additional data collection and analysis. Davoudi believes this will reduce confusion in interpreting LDCT images, and also help improve the criteria for determining which patients would benefit most.
“The good news is, multiple studies are underway, to improve both the screening criteria, and the interpretation and risk-stratification of the results,” he says.
“As our knowledge grows,” he says, “community physicians will increase LDCT patient referrals to a center that can provide high quality screening, diagnosis, and the most effective treatment options to achieve the best possible outcomes.”