Human Papillomavirus Primary Screening and Collaboration in Quality Assurance Work between Laboratories

Cervical screening is changing to the use of human papillomavirus (HPV) testing as the primary screening test. It is essential that the well-established and critically important systems for quality assurance based on laboratory audits of seemingly negative samples taken before HSIL and cervical cancer are maintained. They provide a means of verifying if the actual screening is effective for the intended purpose. Together with international proficiency panels, audits provide a simple and unambiguous way to evaluate if the screening is adequate. Detailed knowledge of how these systems work and how they are dependent on the genotyping of HPV, biobanking, and screening registries is vital to cytologists and pathologists involved in quality assurance work and follow-up of cervical lesions and cervical cancer. Interpretation and communication of outcome and results are equally important for successful quality assurance work and should ideally be done together with expertise in HPV.

The internationally defined procedures for laboratory audit, similar to those used for cytology, require sensitivities before HSIL of >95% and before invasive cervical cancer of >90%. If also results on blinded proficiency panels and international criteria for analytic sensitivity, specificity, and reproducibility are achieved, the HPV screening test can be said to be adequate.

Performance of HPV screening tests in a cervical screening program includes similar laboratory audits as hitherto used for cytology. Similarly, technical proficiency of a laboratory is established using blinded proficiency panels with defined contents of virus. Detailed knowledge of quality assurance work is necessary for cytologists and pathologists. Communication of outcome and results depends on collaboration between laboratories.