Optimal Interval for Routine Cytologic Screening in the United States

Despite the success of cytology-based (Papanicolaou) screening in the United States, over 12 000 women develop and 4000 women die from cervical cancer each year,¹ signaling important flaws in current practice. Paradoxically, a large proportion of women are overscreened,² while at least 50% of cases occur among women who are infrequently or never screened.³ Guidelines have historically recommended screening early and frequently (eg, annually) to offset the poor sensitivity of a single Papanicolaou test. However, a better understanding of the slow natural course of disease, the availability of highly sensitive tests to detect oncogenic human papillomavirus, the causal agent of cervical cancer, and evidence of adverse pregnancy outcomes associated with precancer treatment have triggered momentum toward less aggressive screening in the general population. Consensus guidelines issued this year now recommend screening no earlier than age 21 years and no more frequently than every 3 years for routine cytologic screening to minimize overuse and patient harms while maintaining high levels of cancer prevention.^4- 5 Because the impact of changing guidelines on cervical cancer will not be observed for several years, we used a mathematical simulation model to project the cost-effectiveness of routine cytologic screening at different intervals.