Old, New Pap Methods Equally Good, Dutch Study Finds

Oct. 28 -- TUESDAY, Oct. 27 (HealthDay News) -- Traditional Pap tests and the newer liquid-based cytology are equally reliable in screening for cervical cancer, a new study has found.

In the United States, liquid-based cytology testing has all but replaced the traditional Pap test, but in Europe the debate continues over which method is best, according to Dr. Mark Schiffman, a senior investigator at the U.S. National Cancer Institute, co-author of an editorial accompanying the study's publication in the Oct. 28 issue of the Journal of the American Medical Association.

The study's lead researcher, Albertus G. Siebers, from Radboud University Nijmegen Medical Centre in the Netherlands, reflects that debate. "Liquid-based cytology is neither more sensitive nor more specific in detecting cancer," he said. "However, the decision to convert to liquid-based cytology cannot be based on the performance of the method alone, as other arguments also play an important role."

The difference between the two tests is not in the way samples are collected but in how they are treated in the laboratory. In a traditional Pap test, cells are collected and smeared on a slide for evaluation. In liquid-based cytology, the cells are rinsed in a vial of preservation solution.

The advantage of liquid-based cytology is that it also screens for human papillomavirus (HPV), which causes most cervical cancers.

To find out which test was best, the researchers randomly assigned 89,784 women who participated in the Dutch cervical screening program to have either a traditional Pap tests or a liquid-based cytology test.

"The main finding of the study is that we provided strong evidence that a relatively new screening method is not necessarily better than the old way of screening with conventional PAP smears," Siebers said.

The Dutch screening program did not allow use of liquid-based cytology testing until recently, he said, because officials did not have sufficient data comparing it with the conventional method.