The Swedish National Cervical Screening Registry evaluates and provides data to optimize cervical cancer prevention in Sweden. All cervical cancers diagnosed in Sweden during 10 years, 2002-2011, were identified. 4272 confirmed cancer cases were subjected to a national audit including HPV genotyping.
Formalin-fixed paraffin-embedded (FFPE) samples were used for HPV genotyping. In between each case-block, a blank-block was sectioned, as a control for contamination. The sections were extracted with a heating method and HPV genotyped using modified general primer (MGP)-PCR and Luminex. “HPV negative” cases are being sequenced.
For a valid result the blank-block had to be negative in all tests and the case-block positive for beta-globin. 1560 cases were analysed until February 2016. The most common type was HPV 16 (47%), followed by HPV18 (15%), HPV 45 (7%), HPV 31 (3%), HPV 33 (2%), HPV 52 (1%), HPV 6 (1%), HPV 56 (1%), HPV 39 (1%), HPV 70 (1%), HPV 58 (1%), HPV 59 (1%) and HPV 35 (1%). Single infection was detected in 78% of cases.
Systematic HPV genotyping of all cases of invasive cervical cancer in a country is readily doable as part of monitoring the effectiveness of prevention and continued monitoring of the HPV-type specific disease burden.