The decline in cervical cancer is a success story of cancer research. Although there are reasons to be optimistic about even further decreases in cervical cancer incidence, there still remain some women who are not screened. A meta-analysis by Spence and colleagues published in the August-September 2007 issue of Preventive Medicine shows that undergoing Pap smears irregularly or never was the primary explanation for the development of invasive cervical cancer, followed by false negative tests and poor follow-up of abnormal results.
Papanicolaou and Traut first reported the usefulness of the Papanicolaou smear (''Pap test") for detecting neoplastic cervical cells in 1943. A smear of cells of the uterine cervix indicating the progression of the cancer's growing malignity provided a powerful screening tool that became rapidly used after WWII without its efficacy being evaluated in a randomized control trial. In the United States, the Pap test is credited with having halved the annual cervical cancer incidence rate (from 17.2 to 8.0 per 100,000) and mortality rate (from 6.2 to 2.9) from 1973 to 1999. In 2000, 83% of U.S. women age 18 and older who had not had a hysterectomy reported having had a Pap test within the past 3 years. The recent discovery of a vaccine against human papillomavirus (HPV), the main cause of cervical cancer, opens the way to the primary prevention of the disease.