Screening for cancer quite often produces a false-positive result, and this can lead to costly - and ultimately unnecessary - follow-up testing, according to a new report.

“As new cancer screening tests are developed it is important to consider not only their potential clinical benefits, but also their potential for adverse effects,” lead author Dr. Jennifer Elston Lafata, from Henry Ford Health System in Detroit, said in a statement.

“One such adverse effect is the medical care costs associated with false-positive cancer screening test results.”

Lafata’s group studied data from 1087 subjects who were enrolled in a large managed care organization and participated in the Prostate, Lung, and Colorectal, and Ovarian Cancer Screening Trial.

Forty-three percent of the participants had at least one false-positive screening result, the investigators report in the journal Cancer Epidemiology, Biomarkers, and Prevention. Moreover, 83 percent of these subjects received follow-up care.

The costs of false-positive lung cancer screens were determined through telephone interviews with 98 subjects.

As might be expected, individuals with false-positive results had significantly higher medical expenditures than those without such results, the researchers note. For men and women, the average differences in cost were $1171 and $1024, respectively.

Given the economic, as well as psychological, impact of false-positive screening results, it is imperative that cancer screening is offered in a setting that allows patients to make an informed decision about whether they want to undergo screening or not, the authors conclude.

This is especially true for malignancies such as prostate, lung, and colon cancer, for which the benefits of screening are still uncertain.

SOURCE: Cancer Epidemiology, Biomarkers, and Prevention; December 2004.