Human papillomavirus testing in primary cervical cancer screening

Findings by SBU Alert

Version: 1

Method and target group

Approximately 800 000 cell tests are done annually in Sweden for the detection of potentially invasive cervical cancer in their preinvasive stages. These tests are performed both within and outside of the framework of organized screening programs and are referred to as primary screening. Furthermore, a large number of tests are performed in the further investigation of cervical intraepithelial neoplasias (CIN). Certain types of human papillomavirus (HPV), ie, high risk or oncogenic HPV, are considered to be underlying cause for the most common form of cervical cancer (squamous cell carcinoma). A test has been developed to identify the presence of HPV. This test can be used to supplement cytological testing or replace it as a screening method.

Patient benefits, complications, and side effects

Several studies have investigated the characteristics (sensitivity and specificity) of the HPV test. The long latency period from the onset of HPV infection until the appearance of preinvasive and invasive cancer makes it difficult to assess the benefits to patients from the HPV test. Several assessments of the method are underway in Sweden and other countries, but it will take several years before the results of these studies become available.

Scientific evidence

Currently, there is poor* scientific documentation to show the effects of introducing HPV testing as a primary screening method aimed at reducing morbidity and mortality. There is poor* documentation concerning cost effectiveness. Hence, there is no* scientific evidence to show how screening programs that include HPV testing can be conducted in an optimum way - at what ages and at what intervals. Further assessments of model studies and randomized controlled trials, with the ultimate goal of reducing cancer incidence and increasing patient survival, are needed before the method can be routinely applied in primary screening programs.

Until further evidence becomes available, HPV testing should be used only within the framework of scientific trials. These studies should also examine the psychological and economic consequences of testing. It is essential to adequately inform trial subjects about the deficient evidence concerning the benefits and other consequences of the method.

*This assessment by SBU Alert uses a 4-point scale to grade the quality and evidence of the scientific documentation. The grades indicate: (1) good, (2) moderate, (3) poor, or (4) no scientific evidence on the subject.

This summary is based on a report prepared at SBU in collaboration with Assoc. Prof. Elisabeth Persson, Karolinska Hospital, Stockholm and has been reviewed by Björn Strander, MD, Västra Götalandsregionen.

The complete report is available in Swedish only.

Alert is a joint effort by the Swedish Council on Technology Assessment in Health Care (SBU), the Medical Products Agency, the National Board of Health and Welfare, and the Federation of Swedish County Councils.

References

1. Gynekologisk cellprovskontroll. Förslag till screeningprogram. SoS-rapport, 1998:15, Socialstyrelsen
2. Cuzik J, Sasieni P, Davies P, Adams J, Normand C. Frater A et al. A systemic review of the role of human papillomavirus testing within a cervical screening programme. Health Technol Assess 1999; 3(14).