Is the Pap test dead? Well, no but there is about to be a radical change in how it is used. Last week an FDA advisory panel voted unanimously that the Pap smear should be replaced or at least supplemented by molecular tests for HPV DNA. The story was reported in a recent issue of the New York Times.
Up until now molecular testing was mainly done when the Pap smear was equivocal. The new recommendations reverse the order, however, and advise the use of a molecular test as the front line screen, with Pap smears or biopsies utilized in HPV+ patients. HPV testing has been widely reported to be more sensitive and more objective than a Pap smear. Opponents note that many young women become infected with HPV but clear the infection and have no residual morphologic sequelae. They fear that molecular testing may subject more women, particularly women under 30 years of age, to unnecessary examinations and biopsies. Roche, a maker of one molecular test, notes that they only test for high-risk HPV types 16 and 18.
The Pap smear is not dead; far from it. But its use as THE primary screening technique for cervical dysplasias and carcinomas is going to undergo considerable change in the next few years. The rapidity with which gynecologists switch from doing primary Pap smears to using HPV testing as their primary screen, or offering patients the choice will depend in large part on how soon their professional societies endorse the new FDA recommendations. Ultimately, though, high-volume Pap screening services looking at primarily low-risk patients are going to see a marked reduction in their volumes as molecular testing becomes the front line screen. Institutions such as my own that see a high percentage of high-risk patients will see less dramatic changes in Pap smear utilization.
The Pap smear has been and still is a fantastic tool for diagnosing pre-malignant cervical disease. In countries where it has been utilized routinely, it has resulted in a marked reduction in cervical cancer mortality. In the United States cervical cancer deaths decreased by 70% between 1955 and 1992. Recently, however, the mortality rate, though remaining low, has stabilized with no further reductions. Primary molecular screening, it is argued, is the next step in further lowering cervical cancer-related deaths. Dr. George Papanicolaou would, I think, approve.