JAMA: Hologic's ThinPrep no more effective than Pap smear

October 30, 2009 by MassDevice staff

A multi-year study of nearly 90,000 women in the Netherlands shows that Pap smears are just as effective as ThinPrep liquid cytology tests in detecting signs of cervical cancer, according to the Journal of the American Medical Association.

The results could be a blow to Hologic Inc., the Bedford, Mass.-based women's healthcare company, which has marketed the ThinPrep Pap test since 1996. Company spokesman Jim Culley told MassDevice that the company wouldn't comment on the study at this time.

ThinPrep is a liquid-based test; conventional Pap smears, which have been used since the 1940's, involve a sample being placed on a slide and spray-fixed.

Hologic, which won FDA approval for a ThinPrep integrated imaging device, says its method is "clearer, easier to read, and minimizes obscuring blood, mucus, and non-diagnostic debris, enabling increased accuracy for both manual assessment and computerized assessment of the cells."

There has been a 28 percent reduction in cervical cancers in the United States since the introduction of the ThinPrep, according to Hologic's website. The FDA allows Hologic to label ThinPrep as more effective in revealing early signs of cervical cancer.

But according to the study's authors, there is controversy over claims of the test's diagnostic accuracy, which in part fueled the study. The trial ran from 2003 to 2006 in the Dutch cervical screening program at 246 family practices there.

There was "strong evidence that the performance of liquid-based cytology is not superior to that of the conventional Pap test when applied within a well-organized and quality-controlled cervical screening program," according to the study.

The news may have had a negative effect on Hologic's stock price, which dipped nearly 3.6 percent in trading today.

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