Cervical intra-epithelial neoplasia and koilocytotic lesions of the lower genitalia in an Icelandic population

Human papillomavirus (HPV) in an Icelandic population: the role of HPV DNA testing based on hybrid capture and PCR assays among women with screen-detected abnormal Pap smears

This study was based on 358 cases with abnormal smears referred for colposcopy and HPV DNA testing. We analysed: 1) the frequency of different grades of cyto- and histopathologic findings; 2) the frequency and relative amount of HPV DNA with the hybrid capture assay (HCA) in swabs, and the frequency of HPV with PCR in swabs (-S) and biopsies (-B); and 3) the frequency of HPV types according to the grade of the cyto- and histopathologic findings. Of all cases, 95% were positive with all HPV tests combined. The HCA (HPV: 16, 18, 31, 33, 35, 45, 51, 52 and 56) and the PCR-S and PCR-B (HPV: 16, 18, 31, 33 and 35) tests for high-risk HPV exhibited sensitivities of 57%, 56% and 48%, respectively. The high-grade smears and the high-risk PCR-S HPV had about 80% sensitivity for histologic high-grade lesions compared with around 70% for HCA and the PCR-B. Combining the high-grade smears and the high-risk HPV increased the sensitivity to 93-96%. Among the cervical intraepithelial neoplasia I (CIN I) and the atypical squamous cells of undetermined significance (ASCUS) smears the sensitivity of high-risk HPV for high-grade histologic lesions was 63% for the HCA and 79% for the PCR-S. No correlation was found between the relative amount of HPV DNA detected by HCA and the grade of cyto- and histological lesions. We conclude that the results strongly indicate that HCA is less sensitive than PCR in the diagnosis of high-risk HPV, that swabs are more sensitive than biopsies as a sampling method, that high-risk HPV and high-grade smears are complementary for the diagnosis of high-grade histologic lesions and that the present role of HPV testing in screening could be limited to identifying women with low-grade smears and koilocytotic or low-grade colposcopic biopsies that are at risk of concealing or developing high-grade histologic lesions.

Quality assurance in cervical cancer screening: the Icelandic experience 1964-1993

Monitoring of the effectiveness of a screening programme is vital to ensure optimal use of public resources. This report correlates the results of the Icelandic cervical cancer screening programme with the results of monitoring the programme since 1964. Screening has significantly decreased both the incidence and mortality rates and greatly affected the stage distribution of squamous cell carcinomas, but not of adeno- and adenosquamous carcinomas. In the 25-64 years age group, 84% were screened, 80% of whom were in the organised screening. Smears taken outside the guidelines amounted to 10%. Sensitivity at 1 year was 93% for all smears. At 3 years it was 81% for squamous cell carcinomas, and 42% for adeno-and adenosquamous carcinomas. The rate of unsatisfactory smears was 1.3% for all smears, and 4.5% of the women had abnormal smears (7.7% in the 20-24 years age group). The specificity of the smears test was 98%. It is concluded that monitoring is vital for optimal screening results and although screening is effective in the targeted age group of 25-64 years it should preferably start sooner after age 20 years with a screening interval of 2-3 years.

Effect of organized screening on the risk of cervical cancer. Evaluation of screening activity in Iceland, 1964-1991

The Icelandic Cancer Society launched a screening programme for cervical cancer in June 1964. The aim was to lower the incidence and mortality rates by screening the age group 25-69 at 2- to 3-year intervals. This report analyses the trends in invasive and pre-invasive disease and the distribution of stage and histology, and also evaluates the attendance, the target age group and the screening interval. Before screening, the incidence and mortality rates were on the increase but both have since fallen significantly. Screening greatly affected the rate of microinvasive and stage > or = II squamous-cell carcinomas but not the rate of adeno- and adenosquamous carcinoma. The mean age at detection of invasive cancer has decreased significantly and cancer has become practically non-existent among correctly screened subjects over the age of 69. Among younger women the rates of moderate and severe pre-invasive lesions at first visit increased significantly after 1980. The rate of these lesions was fairly consistently high only 1 year after the first normal visit. It is concluded that organized screening, co-ordinated with spontaneous activity, is effective in reducing the risk of cervical cancer. Regular high attendance and strict follow-up of abnormal cases is a prerequisite for good screening results. Screening should preferably start at about the age of 20 and extend to 60-69 years of age, depending on the number of negative smears by that age. Screening can safely start with a screening interval of 2 to 3 years, but this interval can probably be extended to 4 or 5 years at older ages.