It is not consistent to stop screening women after age 50 because the risk of cervical cancer - even after several negative smear results - is similar to that at younger ages, concludes a study published on bmj.com today.
Ever since the first organised cervical screening programmes started in Europe more than 40 years ago, discussion about the upper age limit for effective screening has been ongoing.
Evidence suggests that repeating smear tests in women aged 60-65 whose previous tests have been normal has little, if any, benefit, and some researchers have proposed that the age limit should be lowered to 50.
So researchers at the Erasmus Medical Center in The Netherlands and the University of Copenhagen in Denmark compared levels of cervical cancer after several negative smears at different ages.
Using data from a national cervical cancer register in The Netherlands (PALGA), they identified 219,000 women aged 45-54 years and 445,000 women aged 30-44 years after their third consecutive negative smear test. The women were then tracked for 10 years, during which time cases of cervical cancer were recorded.
During follow-up, both age groups had similar levels of screening. After 10 years, the incidence of cervical cancer was similar in both groups (41 per 100,000 in the younger group and 36 per 100,000 in the older group), suggesting that among well-screened women without previous abnormalities the risk of developing cervical cancer is independent of age.
Based on these results, it is reasonable to assume that after several consecutive negative results the screening efficiency in terms of detection and prevention of cervical cancer is at the same level around age 50 as it is at younger ages, say the authors.
Whether the observed incidence rates warrant continued screening should be determined by subsequent analysis, but the study suggests that it would not be consistent to stop screening these women while not also relaxing the screening policy for younger women with similar screening histories.
In this respect, our study lends support to the current cervical cancer screening guidelines in England and other developed countries, which do not discriminate women by age up to 65 years, they conclude.
In an accompanying editorial, Björn Strander, Director of cervical screening at Sahlgren's University Hospital in Sweden, suggests we have to pay close attention to developments in invasive cancer in age groups above the cut-off point for screening and be prepared to adjust the screening ages as we learn more.
With modern computer technology we could tailor screening invitations to the individual, he says. Resources could then be allocated away from women who would not benefit from additional smears within a certain number of years to those who would, and the question of whether to screen above the age of 60 could then be answered - yes, for those who benefit the most from it.