Cervical cancer screening

Posted by Alex

Most Pap smears in Canada are performed by family physicians. Despite the tremendous success of the Pap test in reducing the incidence of cancer of the cervix in Canada, 1350 new cases and 390 deaths were predicted to occur in 1996. Incidence rates have dropped from 21.6 per 1000 in 1969 to 10.4 per 1000 in 1990. To further reduce the incidence of invasive carcinoma of the cervix, we need to examine the role of family physicians as the primary providers of screening services.

The success of screening is directly related to the percentage of the target population who are screened and the reliability of the screening test performance. Family physicians have the opportunity and responsibility to influence both of these factors.

Because guidelines for cervical cancer screening conflict, a review of the evidence on which they are based will aid practising family physicians in adopting the most appropriate practice for their patients. In addition, barriers to effective screening will be reviewed with a view to helping family physicians overcome these barriers.

Quality of evidence
The search strategy for this paper included a MEDLINE search using the key words “cancer of cervix,” “Pap test,” and “screening.” In addition, references from all studies and consensus reports were searched for further relevant publications.

This strategy identified limited level I evidence, as defined by The Canadian Task Force on the Periodic Health Examination classification of the levels of scientific evidence. Level I evidence is based on prospective randomized controlled clinical trials. Most of the evidence identified was classified as level II and level III (expert opinion) evidence. Qualitative evidence does not conform to the Canadian Task Force classification but is becoming increasingly accepted within the discipline of family medicine. Evidence from qualitative studies has been included in this paper. The evidence for frequency of screening is perhaps the weakest, despite strong level III recommendations.