What is the Right Age for Cervical Cancer Screening?

ISSN 1745-5057 Women's Health (2010) 6(1), 1–4 10.2217/WHE.09.69 © 2010 Future Medicine Ltd 3‐yearly with 5‐yearly screening, one might say that 3‐yearly screening halves the risk of cervical cancer. The added benefit, however, is ten cancers prevented, and, compared with no screening, this is an a dditional r eduction of 10%. When considering the benefits of cervi‐ cal screening it is useful to consider the ideal screening test. The ideal test would be one that could be applied infrequently and would iden‐ tify all women who, without intervention, would develop cervical cancer (prior to the next screen) and would not identify any women who would not develop cancer. Thus the ultimate goal for cervical screening is not the identification of high‐grade cervical intraepithelial neoplasia (CIN), but a reduction in cancer. It is clear that the majority of such diseases would never pro‐ gress to cancer [2], and recent research demon‐ strates that very little high‐grade CIN in women aged in their early 20s would progress to cancer within 5 years if untreated [3]. We could iden‐ tify women at (relatively) high risk of developing cervical cancer at some time in the future by screening teenagers for human papillomavirus (HPV) DNA, but since there is no simple treat‐ ment for HPV infection, few people favor such an approach. Rather, it is better to wait for the majority of infections that are transitory to clear and then screen older women to identify those who are more likely to have a persistent infection and who are therefore more likely to benefit from intervention. Similarly, there is no advantage to treating a case of high‐grade CIN at 21 rather than 27 years of age if there is little or no chance of it progressing to cancer by 27 years of age, and if the same disease could be treated with no more side‐effects and equal likelihood of success in the older woman. Indeed, if by 27 years of age many of the cases that were present at 21 years of age will have spontaneously cleared, then there may be considerable advantage to waiting. The goal of cervical screening is to prevent cervical cancer. This is achieved by identifying and treating precancer. A secondary benefit of The question as to what the right age is for beginning cervical screening has received much attention in recent months following the tragic death of Jade Goody from cervical cancer at the age of 28 years, and the consequential cam‐ paigning by national newspapers for the age at which women are first invited to screening in England to be lowered from 25 to 20 years. Far less attention has been given to the age at which cervical screening could reasonably stop, although it is an equally important question. Decisions regarding when to screen are complex and require a careful balancing of the benefits and harms of screening, as well as the costs. Such balancing is inherently diffi‐ cult because it is impossible to say how many anxious women or how many premature births balance out one cancer. There is no completely correct answer to the question ‘what is the right age for cervical screening?’, but there are some clearly wrong answers. The precise ages at which women are invited for screening is not fully evidence‐based. Nevertheless, the reason behind such policy decisions should be rational and transparent.