CT screening for lung cancer stirs safety, ethics concerns

January 30, 2007

Lung cancer screening using CT is an exciting prospect, but it could expose patients to dangerous levels of radiation and unnecessary follow-up procedures for false-positive findings, health policy researchers warned in the January issue of the American Journal of Roentgenology.

Lung cancer screening using CT is an exciting prospect, but it could expose patients to dangerous levels of radiation and unnecessary follow-up procedures for false-positive findings, health policy researchers warned in the January issue of the American Journal of Roentgenology.

In an AJR editorial, Dr. Howard Forman of Yale University and Dr. Christoph I. Lee of Stanford University expressed serious reservations about CT screening in lung cancer. They reminded radiologists of their social responsibility to use technology safely and wisely.

The commentary came in response to recently published research from the International Early Lung Cancer Action Program. Eighty percent of people whose lung cancer is caught early with CT screening can expect to live for at least another decade, according to the latest I-ELCAP data published in The New England Journal of Medicine.

Radiation exposure from low-dose cancer screening of 2.5 to 9 mGy has been associated with an increase in cancer, according to the authors. Radiation-induced lung cancer is most problematic for patients in their mid-50s, and smokers may be particularly vulnerable. The editorial claimed that repeated CT procedures would significantly increase cancer risk and possibly result in thousands of radiation-induced lung cancers.

Furthermore, many chest CT findings are benign, and it appears likely that screening would result in a high number of unnecessary biopsies.

"Patients' quality of life will suffer during this continuum of ineffective diagnostic and therapeutic intervention with increased anxiety and loss of productivity. Both ethically and legally, this can be construed as inflicting undue harm on the patient ultimately found to have a benign lesion," Forman and Lee wrote.

Finance is also an issue. Screening and follow-up would cost billions, possibly at the expense of other, perhaps more essential, types of healthcare, the authors wrote. Further research into the cost-effectiveness of CT screening is required.

Despite the potential downsides of CT screening for lung cancer, utilization is expected to rise significantly due to patient demand, as the test gets more publicity from the positive I-ELCAP results. Prior to screening, radiologists have a responsibility to inform patients of the risks, including workup of procedures that ultimately turn out to be false positives.

"As radiologists, we are positioned to be central figures in the exciting endeavor of CT screening for lung cancer. We should be optimistic about the possible social benefits this new technology promises; however, radiologists should also continually evaluate the associated risks and then properly relay these findings to patients," the authors wrote.

For more information from the Diagnostic Imaging archives:

Lung CT screening saves at-risk lives

CT-based informed consent lags in U.S. academic centers

Spotty performance aside, lung CAD proves useful

New lung cancer trial tests FDG-PET's ability to foretell chemotherapy response