Human papillomavirus types in cervical high-grade lesions or cancer among Nordic women-Potential for prevention.

It is valuable to establish a population-based prevaccination baseline distribution of human papillomavirus (HPV) types among women with high-grade cervical intraepithelial neoplasia (CIN) grade 2 or 3 and cervical cancer in order to assess the potential impact of HPV vaccination. In four countries (Denmark, Norway, Sweden, and Iceland), we collected consecutive series of cervical cancers (n = 639) and high-grade precancerous cervical lesions (n = 1240) during 2004-2006 before implementation of HPV vaccination and subjected the specimens to standardized HPV genotyping. The HPV prevalence was 82.7% (95% confidence interval [CI] 79.0-86.4) in CIN2, 91.6% (95% CI 89.7-93.5) in CIN3, and 86.4% (95% CI 83.7-89.1) in cervical cancer. The most common HPV types in CIN2/3 were HPV16 (CIN2: 35.9%, 95% CI 31.2-40.6; CIN3: 50.2%, 95% CI 46.8-53.6) and HPV31 (CIN2: 10.9%, 95% CI 7.8-13.9; CIN3: 12.1%, 95% CI 9.9-14.3), while HPV16 and HPV18 were the most frequent types in cervical cancer (48.8%, 95% CI 44.9-52.7 and 15.3%, 95% CI 12.5-18.1, respectively). The prevalence of HPV16/18 decreased with increasing age at diagnosis in both CIN2/3 and cervical cancer (P < 0.0001). Elimination of HPV16/18 by vaccination is predicted to prevent 42% (95% CI 37.0-46.7) of CIN2, 57% (95% CI 53.8-60.5) of CIN3 and 64% (95% CI 60.3-67.7) of cervical cancer. Prevention of the five additional HPV types HPV31/33/45/52/58 would increase the protection to 68% (95% CI 63.0-72.2) in CIN2, 85% (95% CI 82.4-87.2) in CIN3 and 80% (95% CI 77.0-83.2) in cervical cancer. This study provides large-scale and representative baselines for assessing and evaluating the population-based preventive impact of HPV vaccination.

Population-based service mammography screening: the Icelandic experience.

OBJECTIVE: This study analyzes the efficacy of the Icelandic population-based service mammography screening. MATERIAL AND METHODS: Women aged 40-69 were invited for screening at 2-year intervals starting in November 1987. The study evaluates: (A) attendance and other screened performance parameters during 1998-2010; (B) trends in age-standardized and age-specific incidence rates during 1969-2010 and mortality rates during 1969-2010; and (C) distribution of risk factors and disease specific death rates according to mode of detection. RESULTS: (A) In the age group of 40-69, the average 2-year attendance was 62%, recall rate was 4.1%, needle biopsy rate was 1.3%, surgery rate was 0.6%, invasive cancer rate was 0.4%, and ductal carcinoma in situ (DCIS) rate was 0.06%. (B) The linear incidence trend after the start of screening decreased significantly in the age group 40-49, increased significantly in the age group 50-69, but decreased non-significantly in the age group 70-79. The decreased age-specific incidence in the 70-79 age group was, however, greater than the increased age-specific incidence at the ages 50-69. The mortality rate decreased 41% for all age groups and the linear mortality trend decreased significantly at ages 40-49, 50-69, and 70-79. In the age group 40-74 years, the age-specific mortality decreased by 6.9 cases per 2000 during a 10-year period. (C) Screen-detected women had significantly smaller tumors, more favorable tumor grade, fewer axillary metastases and, after correction for other risk factors, the likelihood of dying from cancer decreased 54% (hazard ratio: 0.46; 95% confidence interval: 0.31-0.69) for these patients compared to cases of nonparticipators. CONCLUSION: The study results confirm acceptable rates of recalls and referrals for further diagnosis and treatment, and significantly decreased breast cancer mortality rate after starting screening.

The accuracy of colposcopic biopsy: analyses from the placebo arm of the Gardasil clinical trials.

We evaluated the overall agreement between colposcopically directed biopsies and the definitive excisional specimens within the context of three clinical trials. A total of 737 women aged 16-45 who had a cervical biopsy taken within 6 months before their definitive therapy were included. Per-protocol, colposcopists were to also obtain a representative cervical biopsy immediately before definitive therapy. Using adjudicated histological diagnoses, the initial biopsies and the same day biopsies were correlated with the surgically excised specimens. The overall agreement between the biopsies taken within 6 months of definitive therapy, and the definitive therapy diagnoses was 42% (weighted kappa = 0.34) (95% CI: 0.29-0.39). The overall underestimation of cervical intraepithelial neoplasia grade 2/3 or adenocarcinoma in situ (CIN2-3/AIS) and CIN3/AIS was 26 and 42%, respectively. When allowing for one degree of variance in the correlation, the overall agreement was 92% for CIN2-3/AIS. The overall agreement between the same day biopsy and definitive therapy specimen was 56% (weighted kappa = 0.41) (95% CI: 0.36-0.47), and the underestimation of CIN2-3/AIS was 57%. There were significant associations in the agreement between biopsies and excisional specimen diagnoses when patients were stratified by age, number of biopsies, lesion size, presence of human papillomavirus (HPV)16/18 and region. Of 178 diagnostic endocervical curettages performed, 14 (7.9%) found any HPV disease. Colposcopic accuracy improved when CIN2 and CIN3/AIS were grouped as a single predictive measure of high-grade disease. Colposcopy functioned well when allowed a one-degree difference between the biopsy and the surgical histologic interpretations, as done in clinical practice. Taking more than one biopsy improved colposcopic accuracy and could improve patient management.

Four year efficacy of prophylactic human papillomavirus quadrivalent vaccine against low grade cervical, vulvar, and vaginal intraepithelial neoplasia and anogenital warts: randomised controlled trial.

OBJECTIVES: To evaluate the prophylactic efficacy of the human papillomavirus (HPV) quadrivalent vaccine in preventing low grade cervical, vulvar, and vaginal intraepithelial neoplasias and anogenital warts (condyloma acuminata). DESIGN: Data from two international, double blind, placebo controlled, randomised efficacy trials of quadrivalent HPV vaccine (protocol 013 (FUTURE I) and protocol 015 (FUTURE II)). The trials were to be 4 years in length, and the results reported are from final study data of 42 months' follow-up. SETTING: Primary care centres and university or hospital associated health centres in 24 countries and territories around the world. PARTICIPANTS: 17 622 women aged 16-26 years enrolled between December 2001 and May 2003. Major exclusion criteria were lifetime number of sexual partners (>4), history of abnormal cervical smear test results, and pregnancy. INTERVENTION: Three doses of quadrivalent HPV vaccine (for serotypes 6, 11, 16, and 18) or placebo at day 1, month 2, and month 6. MAIN OUTCOME MEASURES: Vaccine efficacy against cervical, vulvar, and vaginal intraepithelial neoplasia grade I and condyloma in a per protocol susceptible population that included subjects who received all three vaccine doses, tested negative for the relevant vaccine HPV types at day 1 and remained negative through month 7, and had no major protocol violations. Intention to treat, generally HPV naive, and unrestricted susceptible populations were also studied. RESULTS: In the per protocol susceptible population, vaccine efficacy against lesions related to the HPV types in the vaccine was 96% for cervical intraepithelial neoplasia grade I (95% confidence interval 91% to 98%), 100% for both vulvar and vaginal intraepithelial neoplasia grade I (95% CIs 74% to 100%, 64% to 100% respectively), and 99% for condyloma (96% to 100%). Vaccine efficacy against any lesion (regardless of HPV type) in the generally naive population was 30% (17% to 41%), 75% (22% to 94%), and 48% (10% to 71%) for cervical, vulvar, and vaginal intraepithelial neoplasia grade I, respectively, and 83% (74% to 89%) for condyloma. CONCLUSIONS: Quadrivalent HPV vaccine provided sustained protection against low grade lesions attributable to vaccine HPV types (6, 11, 16, and 18) and a substantial reduction in the burden of these diseases through 42 months of follow-up. TRIAL REGISTRATIONS: NCT00092521 and NCT00092534.

Impact of human papillomavirus (HPV)-6/11/16/18 vaccine on all HPV-associated genital diseases in young women.

BACKGROUND: The impact of the prophylactic vaccine against human papillomavirus (HPV) types 6, 11, 16, and 18 (HPV6/11/16/18) on all HPV-associated genital disease was investigated in a population that approximates sexually naive women in that they were "negative to 14 HPV types" and in a mixed population of HPV-exposed and -unexposed women (intention-to-treat group). METHODS: This analysis studied 17 622 women aged 15-26 years who were enrolled in one of two randomized, placebo-controlled, efficacy trials for the HPV6/11/16/18 vaccine (first patient on December 28, 2001, and studies completed July 31, 2007). Vaccine or placebo was given at day 1, month 2, and month 6. All women underwent cervicovaginal sampling and Papanicolaou (Pap) testing at day 1 and every 6-12 months thereafter. Outcomes were any cervical intraepithelial neoplasia; any external anogenital and vaginal lesions; Pap test abnormalities; and procedures such as colposcopy and definitive therapy. Absolute rates are expressed as women with endpoint per 100 person-years at risk. RESULTS: The average follow-up was 3.6 years (maximum of 4.9 years). In the population that was negative to 14 HPV types, vaccination was up to 100% effective in reducing the risk of HPV16/18-related high-grade cervical, vulvar, and vaginal lesions and of HPV6/11-related genital warts. In the intention-to-treat group, vaccination also statistically significantly reduced the risk of any high-grade cervical lesions (19.0% reduction; rate vaccine = 1.43, rate placebo = 1.76, difference = 0.33, 95% confidence interval [CI] = 0.13 to 0.54), vulvar and vaginal lesions (50.7% reduction; rate vaccine = 0.10, rate placebo = 0.20, difference = 0.10, 95% CI = 0.04 to 0.16), genital warts (62.0% reduction; rate vaccine = 0.44, rate placebo = 1.17, difference = 0.72, 95% CI = 0.58 to 0.87), Pap abnormalities (11.3% reduction; rate vaccine = 10.36, rate placebo = 11.68, difference = 1.32, 95% CI = 0.74 to 1.90), and cervical definitive therapy (23.0% reduction; rate vaccine = 1.97, rate placebo = 2.56, difference = 0.59, 95% CI = 0.35 to 0.83), irrespective of causal HPV type. CONCLUSIONS: High-coverage HPV vaccination programs among adolescents and young women may result in a rapid reduction of genital warts, cervical cytological abnormalities, and diagnostic and therapeutic procedures. In the longer term, substantial reductions in the rates of cervical, vulvar, and vaginal cancers may follow.

A pooled analysis of continued prophylactic efficacy of quadrivalent human papillomavirus (Types 6/11/16/18) vaccine against high-grade cervical and external genital lesions.

Quadrivalent human papillomavirus (HPV) vaccine has been shown to provide protection from HPV 6/11/16/18-related cervical, vaginal, and vulvar disease through 3 years. We provide an update on the efficacy of the quadrivalent HPV vaccine against high-grade cervical, vaginal, and vulvar lesions based on end-of-study data from three clinical trials. Additionally, we stratify vaccine efficacy by several baseline characteristics, including age, smoking status, and Papanicolaou (Pap) test results. A total of 18,174 females ages 16 to 26 years were randomized and allocated into one of three clinical trials (protocols 007, 013, and 015). Vaccine or placebo was given at baseline, month 2, and month 6. Pap testing was conducted at regular intervals. Cervical and anogenital swabs were collected for HPV DNA testing. Examination for the presence of vulvar and vaginal lesions was also done. Endpoints included high-grade cervical, vulvar, or vaginal lesions (CIN 2/3, VIN 2/3, or VaIN 2/3). Mean follow-up time was 42 months post dose 1. Vaccine efficacy against HPV 6/11/16/18-related high-grade cervical lesions in the per-protocol and intention-to-treat populations was 98.2% [95% confidence interval (95% CI), 93.3-99.8] and 51.5% (95% CI, 40.6-60.6), respectively. Vaccine efficacy against HPV 6/11/16/18-related high-grade vulvar and vaginal lesions in the per-protocol and intention-to-treat populations was 100.0% (95% CI, 82.6-100.0) and 79.0% (95% CI, 56.4-91.0), respectively. Efficacy in the intention-to-treat population tended to be lower in older women, women with more partners, and women with abnormal Pap test results. The efficacy of quadrivalent HPV vaccine against high-grade cervical and external anogenital neoplasia remains high through 42 months post vaccination.

Evaluation of quadrivalent HPV 6/11/16/18 vaccine efficacy against cervical and anogenital disease in subjects with serological evidence of prior vaccine type HPV infection.

OBJECTIVE: In the quadrivalent (types 6/11/16/18) HPV vaccine (GARDASIL/SILGARD) clinical program, 73% of women aged 16-26 were naïve to all vaccine HPV types. In these women, prophylactic administration of the vaccine was highly effective in preventing HPV 6/11/16/18-related cervical disease. Of the remaining women, 15% of had evidence of past infection with one or more vaccine HPV types (seropositive and DNA negative) at the time of enrollment. Here we present an analysis in this group of women to determine the efficacy of the HPV 6/11/16/18 vaccine against new cervical and external anogenital disease related to the same vaccine HPV type which had previously been cleared. Vaccine tolerability in this previously infected population was also assessed. METHODS: 18,174 women were enrolled into 3 clinical studies. The data presented comprise a subset of these subjects (n = 2,617) who were HPV seropositive and DNA negative at enrollment (for >or=1 vaccine type). In each study, subjects were randomized in a 1:1 ratio to receive HPV 6/11/16/18 vaccine or placebo at day 1, month 2 and month 6 (without knowledge of baseline HPV status). Procedures performed for efficacy data evaluation included detailed genital examination, Pap testing, and collection of cervicovaginal and external genital specimens. Analyses of efficacy were carried out in a population stratified by HPV serology and HPV DNA status at enrollment. RESULTS: Subjects were followed for an average of 40 months. Seven subjects in the placebo group developed cervical disease, and eight subjects developed external genital disease related to a vaccine HPV type they had previously encountered. No subject receiving HPV 6/11/16/18 vaccine developed disease to a vaccine HPV type to which they were seropositive and DNA negative at enrolment. CONCLUSIONS: These results suggest that natural HPV infection-elicited antibodies may not provide complete protection over time, however the immune response to the HPV 6/11/16/18 vaccine appears to prevent reinfection or reactivation of disease with vaccine HPV types. Vaccine-related adverse experiences were higher among subjects receiving vaccine, mostly due to increased injection site adverse experiences.

The impact of quadrivalent human papillomavirus (HPV; types 6, 11, 16, and 18) L1 virus-like particle vaccine on infection and disease due to oncogenic nonvaccine HPV types in sexually active women aged 16-26 years.

BACKGROUND: We evaluated the impact of a quadrivalent human papillomavirus (HPV) vaccine on infection and cervical disease related to 10 nonvaccine HPV types (31, 33, 35, 39, 45, 51, 52, 56, 58, and 59) associated with >20% of cervical cancers. The population evaluated included HPV-naive women and women with preexisting HPV infection and/or HPV-related disease at enrollment. METHODS: Phase 3 efficacy studies enrolled 17,622 women aged 16-26 years. Subjects underwent cervicovaginal sampling and Pap testing on day 1 and then at 6-12-month intervals for up to 4 years. HPV typing was performed on samples from enrollment and follow-up visits, including samples obtained for diagnosis or treatment of HPV-related disease. All subjects who received 1 dose and returned for follow-up were included. RESULTS: Vaccination reduced the rate of HPV-31/33/45/52/58 infection by 17.7% (95% confidence interval [CI], 5.1% to 28.7%) and of cervical intraepithelial neoplasia (CIN) 1-3 or adenocarcinoma in situ (AIS) by 18.8% (95% CI, 7.4% to 28.9%). Vaccination also reduced the rate of HPV-31/58/59-related CIN1-3/AIS by 26.0% (95% CI, 6.7% to 41.4%), 28.1% (95% CI, 5.3% to 45.6%), and 37.6% (95% CI, 6.0% to 59.1%), respectively. Although a modest reduction in HPV-31/33/45/52/58-related CIN2 or worse was observed, the estimated reduction was not statistically significant. CONCLUSIONS: These cross-protection results complement the vaccine's prophylactic efficacy against disease associated with HPV-6, -11, -16, and -18. Long-term monitoring of vaccinated populations are needed to fully ascertain the population-based impact and public health significance of these findings. TRIAL REGISTRATION: ClinicalTrials.gov identifiers: NCT00092521 , NCT00092534 , and NCT00092482.

The impact of quadrivalent human papillomavirus (HPV; types 6, 11, 16, and 18) L1 virus-like particle vaccine on infection and disease due to oncogenic nonvaccine HPV types in generally HPV-naive women aged 16-26 years.

BACKGROUND: Human papillomavirus (HPV)-6/11/16/18 vaccine reduces the risk of HPV-6/11/16/18-related cervical intraepithelial neoplasia (CIN) 1-3 or adenocarcinoma in situ (AIS). Here, its impact on CIN1-3/AIS associated with nonvaccine oncogenic HPV types was evaluated. METHODS: We enrolled 17,622 women aged 16-26 years. All underwent cervicovaginal sampling and Pap testing at regular intervals for up to 4 years. HPV genotyping was performed for biopsy samples, and histological diagnoses were determined by a pathology panel. Analyses were conducted among subjects who were negative for 14 HPV types on day 1. Prespecified analyses included infection of 6 months' duration and CIN1-3/AIS due to the 2 and 5 most common HPV types in cervical cancer after HPV types 16 and 18, as well as all tested nonvaccine types. RESULTS: Vaccination reduced the incidence of HPV-31/45 infection by 40.3% (95% confidence interval [CI], 13.9% to 59.0%) and of CIN1-3/AIS by 43.6% (95% CI, 12.9% to 64.1%), respectively. The reduction in HPV-31/33/45/52/58 infection and CIN1-3/AIS was 25.0% (95% CI, 5.0% to 40.9%) and 29.2% (95% CI, 8.3% to 45.5%), respectively. Efficacy for CIN2-3/AIS associated with the 10 nonvaccine HPV types was 32.5% (95% CI, 6.0% to 51.9%). Reductions were most notable for HPV-31. CONCLUSIONS: HPV-6/11/16/18 vaccine reduced the risk of CIN2-3/AIS associated with nonvaccine types responsible for approximately 20% of cervical cancers. The clinical benefit of cross-protection is not expected to be fully additive to the efficacy already observed against HPV-6/11/16/18-related disease, because women may have >1 CIN lesion, each associated with a different HPV type. TRIAL REGISTRATION: ClinicalTrials.gov identifiers: NCT00092521 , NCT00092534 , and NCT00092482.

The efficacy of HPV 16/18 vaccines on sexually active 18-23 year old women and the impact of HPV vaccination on organized cervical cancer screening.

OBJECTIVE: Evaluate the efficacy of catch-up HPV vaccination in sexually active young women and the potential impact of HPV vaccines on the practice of organized screening. SAMPLE: (1) Women enrolled in the Future II study and (2) from a separate population-based study in Iceland. METHODS: (1) Analysis of cytological and histological results and colposcopic examinations among 710 women, aged 18-23, with less than five sexual partners, irrespectively of baseline HPV status at enrolment. (2) The impact on screening practice as determined by evaluating the distribution of 12 oncogenic HPV types in 582 cervical intraepithelial lesions (CIN 2-3) and cancer cases. MAIN OUTCOME MEASURES: (1) Distribution of evaluated parameters according to age at enrolment. (2) Age distribution of four HPV groups, within age classes and HPV groups: mean time to development of lesions, mean time to development of CIN 2-3+, cumulative frequency for CIN 2-3+ lesions after the last normal smear. RESULTS: (1) After an average 52 months of post-enrolment follow-up, significant reductions in all evaluated parameters were observed in women aged 18-19 at enrolment. (2) Among women <25 years, the proportion of cases with only HPV 16/18 was significantly lower and the proportion containing HPV16/18 plus > or =1 out of 10 non-vaccine HPV types (31/33/45/52/58/35/39/51/56/59) was higher than at age 25-49. The proportion of cases containing only the non-vaccine types was the same within all age groups. Cases with HPV 16/18 and some non-vaccine types decreased significantly with age and accumulated more slowly after the last negative smear. CONCLUSIONS: Catch-up vaccination of younger women should be considered in the context of sexual practices and the effects of prevalent disease on observed vaccine efficacy. Current data do not support a change in the lower age limit or screening intervals for women.

HPV antibody levels and clinical efficacy following administration of a prophylactic quadrivalent HPV vaccine.

The efficacy of the quadrivalent Human Papillomavirus (HPV) vaccine is thought to be mediated by humoral immunity. We evaluated the correlation between quadrivalent HPV vaccine-induced serum anti-HPV responses and efficacy. 17,622 women were vaccinated at day 1, and months 2 and 6. At day 1 and at 6-12 months intervals for up to 48 months, subjects underwent Papanicolaou and genital HPV testing. No immune correlate of protection could be found due to low number of cases. Although 40% of vaccine subjects were anti-HPV 18 seronegative at end-of-study, efficacy against HPV 18-related disease remained high (98.4%; 95% CI: 90.5-100.0) despite high attack rates in the placebo group. These results suggest vaccine-induced protection via immune memory, or lower than detectable HPV 18 antibody titers.

HPV genotypes in CIN 2-3 lesions and cervical cancer: a population-based study.

The distribution of human papillomavirus (HPV) varies between countries and continents leading to different effectiveness of upcoming prophylactic HPV vaccines. This study analyses the HPV distribution in CIN 2-3, recurrent CIN 2-3 and cervical cancer in Iceland. About 80% of incident cases with CIN 2-3 lesions in 1990 and 1999, 99% of cancer cases in 1990-1994 and 1999-2003, and cases with recurrent CIN 2-3 after conization in 1990 were tested with PCR analysis for the presence of 12 oncogenic HPV types. About 95% of the CIN 2-3 and 92% of the cancer cases tested positive for the included HPV types. HPV 16 was the most frequent type followed by HPV 33, 31, 52, 35, 18, 58, 56, 39, 45, 59 in CIN 2-3 and by HPV 18, 33 45, 31, 39, 52, 35, 51, 56 in cancer. HPV 16 and 18 were associated with a significantly increased cancer risk and HPV 52 and 31 with decreased cancer risk compared to the risk of CIN 3. The HPV distribution differed between histological cancer types, stages and age groups. The number of HPV types was not a significant predictor of cancer. Oncogenic HPV types were found in all persistent or recurrent CIN 2-3 disease after conization. Vaccination against HPV 16/18 is estimated to achieve a minimum 40% reduced rate of CIN 2-3 and a minimum 60% reduced cancer rate. This rate could, however, be increased to 95% and 92% respectively by including all the 12 HPV types tested for in this study.

Is it rational to start population-based cervical cancer screening at or soon after age 20? Analysis of time trends in preinvasive and invasive diseases.

The effect of starting screening at age 20 in 1988 was assessed by analysing (a) the age-specific incidence and distribution of stage and histology of invasive diseases, and (b) the detection rates of histologic moderate to high-grade intraepithelial neoplasia (CIN 2-3/AIS), and 1st abnormal cytology and repeat low-grade cytology after follow-up observation. Cancer incidence increased significantly at age 25-34 after 1979 due to early stage squamous cell and adenocarcinoma. After an initial increased rate of preinvasive disease, CIN 3 decreased significantly at age 30-34 after 1988, at age 25-29 after 1993, and levelled out after 1998 at age 20-24. The rates of CIN 2 levelled out after 1998. The rates of repeat low-grade smears decreased after observation at age 20-24 by 80%. The study confirms an increasing rate of preinvasive and invasive disease among younger women and indicates the benefit of starting organised screening at 2-3 year intervals soon after age 20.

Effectiveness of cervical cancer screening in Iceland, 1964-2002: a study on trends in incidence and mortality and the effect of risk factors.

BACKGROUND: Data on cervical cancer screening programs that have covered a whole nation over a prolonged time are scarce. The effectiveness of a 40-year established nationwide cervical screening program has been evaluated to define optimal age limits and screening intervals. METHODS: Trends in incidence and mortality by calendar time, age, histology, stage and attendance during 1964-2002 and the predictive power of calendar year, age, stage and histology on the cause-specific mortality rate were analyzed. RESULTS: The rate of squamous cell carcinoma decreased significantly, but the rate of adenocarcinoma increased. The age-specific incidence and cause-specific mortality decreased significantly for all age groups except those women aged 20-29 years. An increased age-specific incidence rate, confined to stage I, was observed in the age group 20-39 years after 1980 and a positive correlation was observed between early attendance and the rate of microinvasive squamous (stage IA) cell carcinoma and adenocarcinoma in this age group. The cumulative incidence of invasive disease started to increase two years after the last negative smear. Stage was the strongest risk factor, followed by age and calendar time, and to a lesser degree histology. CONCLUSIONS: The results confirm the effectiveness of the screening program and support the recommendation that screening should commence below age 25 with a maximum of 3-year initial screening intervals. The interval can then be extended after age 40 and stopped after age 65.

Longitudinal trends in cervical cytological lesions and the effect of risk factors. A 30-year overview.

BACKGROUND: Cytological preinvasive changes are important precursors in cervical cancer, therefore variations in their trends affect screening guidelines. METHODS: Trends in cytological preinvasive changes following the 1st to 5th screening visits in the 20-34 and 35-69 year age groups were analyzed for the period 1979-2002: a) the incidence rate (absolute risk) of higher grade cytology and the relative risk of risk factors on this rate; b) the cumulative incidence of low-grade and higher grade smears after normal and abnormal screening results; c) the cumulative incidence of higher grade cytology at a fixed risk level after normal screening results; and d) the prevalence of higher grade smears at first screening visit in the 20-24/25-29 year age groups during 1971-2002. RESULTS: An increased trend in the prevalence of higher-grade smears was observed at the first screening visit after 1980. The main risk variables for higher-grade smears in both age groups were low-grade changes and inflammation followed in the younger age group by calendar year. However, age correlated with a decreased risk ratio. After normal screening the cumulative incidence rate of low and higher-grade smears increased almost linearly with time. The screening interval before diagnosis of higher-grade smears increased with both age and number of normal visits, but leveled out after the age of 35-40. CONCLUSIONS: Trends in higher-grade smears indicate that screening should preferably start before age 25 with a maximum interval of 3 years. The interval can be extended after age 35-40. Low-grade smears or inflammation need closer follow-up.

Longitudinal trends in cervical histological lesions (CIN 2-3+): a 25-year overview.

BACKGROUND: Trends in CIN 2-3+ lesions affect the choice of target age group and screening interval. METHODS: The following analyses were performed for CIN 2-3+ following 1st to 5th screening visits in the 20-34/35-69 age groups during 1979-2002: a) the relative risk of age and calendar year; b) the cumulative incidence rate after normal or low or higher grade cytology; c) the proper screening interval to detect these lesions at a fixed risk level after normal screening visits; d) the predictive power of these lesions for diagnosis of cancer after first biopsy; e) the prevalence rates in the 20-24/25-29 year age groups at first and at all subsequent screening visits. RESULTS: The cumulative rate decreased with the number of screening visits and advancing age. After normal and low-grade cytology the cumulative rate increased linearly but slowly with time but after higher grade cytology the rate was relatively stable within one year. Age and calendar year are important risk factors in younger women. The prevalence of CIN 2-3+ increased significantly at 1st visit in the 20-24 age group at the same time as the population prevalence in the 25-29 age group decreased significantly. CIN 2 was at lower risk than CIN 3 of being diagnosed with cancer. CONCLUSIONS: The results indicate that screening should preferably start before age 25 with a maximum interval of 3 years, whereas the interval can be extended to 4-5 years at age 35-40. CIN 2 have a different risk profile compared to CIN 3.

HPV subtypes and immunological parameters of cervical cancer in Iceland during two time periods, 1958-1960 and 1995-1996.

OBJECTIVE: Cervical cancer is a disease caused in part by an infection with an oncogenic subtype of human papillomavirus (HPV). In this study we analysed all cervical cancer samples diagnosed in Iceland during two periods, 1958-1960 and 1995-1996, and asked whether significant changes in viral or immunological parameters had occurred over a period that spanned both significant changes in sexual attitude and the implementation of organized screening for cervical cancer. METHODS: Samples from 47 patients (46 squamous cell carcinomas (SCC) and 1 adenosquamous carcinoma (ASC)) in the first period and 30 patients (20 SCC, 4 ASC, and 6 adenocarcinomas (AC)) in the later period were analysed for viral subtype and expression of Fas, FasL, MHC class I, p53 and apoptosis. RESULTS: AC and ASC are proportionately much more common today than 40 years ago (30% vs 2%). The distribution of HPV in cervical cancer is similar in both periods, with HPV16 found in 75% and HPV18 in 13% of cases. Other HPV types found were 31,33,45, and 59. No significant differences were found in the immunological profiles of tumors from the two periods except that a higher fraction of SCC in the later period stained positive for FasL. When SCC are compared with AC/ASC, the latter have less expression of MHC class I, less expression of Fas, and stronger FasL expression. CONCLUSIONS: AC/ASC tumors show some immunological features that suggest that they are more resistant to immune attack than SCC.