Randomized evaluation trial on automation-assisted screening for cervical cancer: results after 777,000 invitations.

OBJECTIVES: New cervical screening methods have been developed. They seem to become accepted in routine use without randomized trials, within existing screening programmes. Our aim was to evaluate, in a randomized setting, the performance of automation-assisted cytological screening in routine use compared with conventional Papanicoalou (Pap) screening. SETTING: This prospective study was based on a 1:2 individually randomized design. Altogether 777,144 women were invited to attend the routine screening programme. RESULTS: Automation-assisted screening found more Pap class III (LSIL+) findings compared with conventional study arm, relative risk (RR) 1.08 (confidence interval 1.01-1.15). Also, detection rates of verified pre-cancers were more common in automation-assisted arm, RR 1.11 (1.02-1.21). CONCLUSIONS: Automation-assisted screening performed well compared with conventional screening. The difference was smaller than reported in non-randomized studies. A new technique may assume several years to reach the ultimate quality and can add costs without improving efficacy. Follow-up of prevented cervical cancers is required.

Significant variation in performance does not reflect the effectiveness of the cervical cancer screening programme in Finland.

AIM: To characterise the variation in performance indicators of the Finnish cervical screening programme by screening laboratory and to assess whether the performance affects cervical cancer incidence. METHODS: Cervical cancer screening data from 1999 to 2003 from six well-established laboratories were used to analyse rates for follow-up recommendations, referrals and histologically confirmed dysplastic lesions. Laboratory-specific cervical cancer incidences for 1954-2003 were assessed using the cancer registry files. RESULTS: Differences in follow-up recommendations were up to 3.1-fold and 2.2-fold in referrals; differences in the rates for CIN1, CIN2 and CIN3+ were up to 4.5-, 4.7-, and 1.5-fold, respectively. Pre-screening incidence rates for cervical cancer varied 1.5-fold by laboratory, with no major differences in the incidence trends since the onset of screening. CONCLUSION: The performance of a cervical screening programme differs by screening laboratory but does not materially affect the overall programme effectiveness. This leads to variation in cost-effectiveness and probably in avoidable adverse effects. In cervical cancer screening studies, the outcome should be selected as closely as possible to the true measure of programme effectiveness, prevented invasive cervical cancers and subsequent deaths.

A randomised public-health trial on automation-assisted screening for cervical cancer in Finland: performance with 470,000 invitations.

Our objective was to evaluate automation-assisted screening, in comparison to the conventional method, in a routine population-based cervical cancer-screening programme. Our study is based on an individually randomised design involving approximately 160,000 invitees and 110,000 attendees every year. From 1999 to 2001, 471,297 women were invited to attend and 330,445 smears were screened (attendance rate 70.1%), of which 220,254 were tested conventionally and 110,191 were tested using the automation-assisted method. Cytologic Papanicolaou group II findings were reported slightly more often (RR = 1.04) in the automation-assisted method than in the conventional screening arm. There were 1,291 cases of histologically confirmed dysplasia or carcinoma (0.4% of the screened), one-third of which were severe dysplasia or a more severe finding (CIN3+). The detection rates of histologically verified findings were similar between the 2 screening arms. In Finland, the screening programme has been effective. As the detection rates, particularly of CIN3+, were similar between the screening arms, we will continue the automation-assisted method in the routine screening programme. Further follow-up for interval cancer incidence is required, however, to measure if the effect of screening is the same between the arms. A similar evaluation design is feasible to any other major or competing modification of the screening test or other element in the programme.