High risk Human Papilloma Virus (HPV) testing is currently implemented in a randomized controlled fashion as the primary test in the Norwegian cervical screening programme. We present detailed evaluation of the cancer cases identified.
The implementation involves women in the age-group 34-69 years in four Norwegian counties, counting approximately 285.000 women. The follow-up algorithm after abnormal HPV-test is more aggressive than for abnormal cytology, and more women are referred to immediate biopsy, and thereby potentially earlier detection of cancers. To compare symptomatic and screening detected cancer cases among those allocated to HPV test or cytology, we included women with at least 15 months follow-up since screening. Description of screening results (cytology/HPV status/genotype), screening history, symptoms, FIGO-stadium and age of the cancer-diagnosed women are presented.
By March 2016, approximately 140.0000 women have been screened, half with HPV test and half with cytology. Around 32.000 women have had adequate follow-up time. A total of 25 cancer cases were identified; 14 cases among HPV-screened (12 squamous cell carcinoma, 2 adenocarcinoma) and 11 among cytology-screened (9 squamous cell carcinoma, 1 adenocarcinoma, 1 other cervical cancer type). 86% of the cancer cases was diagnosed in women below 50 years after primary HPV test compared to 46% in the cytology group. More than 50% of the women diagnosed with cancer were screened sub-optimally. Around 80% of the cancers were related to HPV16 and HPV18, and the majority of the cancers were FIGO stadium I. Updated results will be presented at the conference.
As we expected, observed number of cancer cases were comparable in HPV-screening and cytology screening, suggesting high performance of HPV-testing in routine screening.