Adriaan J. C. van den Brule

Sexually Transmitted Infection as a Cause of Anal Cancer

Interviews were carried out with 423 women and 93 men with invasive or in situ anal cancer in Denmark and Sweden in a search for clues to the aetiology of this neoplasm. Patients with rectal adenocarcinoma (n = 534) and persons drawn from the background population (n = 554) served as controls. Multivariate logistic regression analyses confirmed previous observations of a strong association between either male homosexual experience or a history of anogenital warts and the risk for anal cancer. Moreover, hitherto unknown, but strong and consistent associations were observed between measures of high heterosexual activity and the risk for anal cancer among both sexes. Polymerase chain reaction analysis revealed human papilloma-virus DNA in the majority (88%) of anal cancer specimens but in none of 20 examined rectal adenocarcinomas. It is concluded that most anal cancers appear to be caused by sexually transmitted types of human papillomaviruses and, consequently, that anal cancer is a potentially preventable neoplasm.

GP5+/6+ PCR followed by Reverse Line Blot Analysis Enables Rapid and High-Throughput Identification of Human Papillomavirus Genotypes

ABSTRACT In this study, we developed a simple and fast typing procedure for 37 mucosotropic human papillomavirus (HPV) types using a nonradioactive reverse line blotting (RLB) procedure for general primer (GP5+/6+) PCR products. This system has the advantages not only that in a simple format, up to 42 PCR products can be simultaneously typed per membrane per day, but also that after stripping, the membranes can be easily rehybridized at least 15 times without a loss of signal. RLB appeared highly specific, and its sensitivity was identical to that of conventional typing performed with type-specific oligonucleotide probes in an enzyme immunoassay (EIA). The performance of RLB typing was evaluated with samples of HPV-positive cervical scrapings (n = 196) and biopsies of cervical premalignant lesions (n = 100). The distribution of HPV genotypes detected in these samples was in line with the distribution expected on the basis of literature data. In addition, RLB and EIA typing procedures were compared for the typing of high-risk HPV types in GP5+/6+ PCR products of 210 cervical scrapings from high-risk HPV-positive women who participated in a population-based screening program. The typing procedures had an excellent overall agreement rate of 96.5% (kappa value, 0.77). RLB was successful in detecting multiple HPV infections as well as single infections. In conclusion, the GP5+/6+ PCR-RLB procedure appeared to be a reliable and simple approach that may be of great value for large epidemiological studies, population-based cervical cancer screening programs, and vaccination trials that require high-throughput HPV typing.

Type specific persistence of high risk human papillomavirus (HPV) as indicator of high grade cervical squamous intraepithelial lesions in young women: population based prospective follow up study

Abstract Objectives: To investigate the role of human papillomavirus (HPV) in the development of cervical neoplasia in women with no previous cervical cytological abnormalities; whether the presence of virus DNA predicts development of squamous intraepithelial lesion; and whether the risk of incident squamous intraepithelial lesions differs with repeated detection of the same HPV type versus repeated detection of different types. Design: Population based prospective cohort study. Setting: General population in Copenhagen, Denmark. Participants: 10 758 women aged 20-29 years followed up for development of cervical cytological abnormalities; 370 incident cases were detected (40 with atypical squamous cells of undetermined significance, 165 with low grade squamous intraepithelial lesions, 165 with high grade squamous intraepithelial lesions). Main outcome measures: Results of cervical smear tests and cervical swabs at enrolment and at the second examination about two years later. Results: Compared with women who were negative for human papillomavirus at enrolment, those with positive results had a significantly increased risk at follow up of having atypical cells (odds ratio 3.2, 95% confidence interval 1.3 to 7.9), low grade lesions (7.5, 4.8 to 11.7), or high grade lesions (25.8,15.3 to 43.6). Similarly, women who were positive for HPV at the second examination had a strongly increased risk of low (34.3,17.6 to 67.0) and high grade lesions (60.7, 25.5 to 144.0). For high grade lesions the risk was strongly increased if the same virus type was present at both examinations (813.0, 168.2 to 3229.2). Conclusions: Infection with human papillomavirus precedes the development of low and high grade squamous intraepithelial lesions. For high grade lesions the risk is greatest in women positive for the same type of HPV on repeated testing.

Human papillomavirus 16 load in normal and abnormal cervical scrapes: an indicator of CIN II/III and viral clearance.

The relation between human papillomavirus type 16 (HPV 16) viral load in cervical scrapes and development of high‐grade cervical intraepithelial neoplasia (CIN II or III) was studied in a nested case‐control study of women with normal cytology (group A) and in a cohort of women with abnormal cytology (group B). HPV 16 DNA load was determined using a quantitative real‐time PCR assay. In group A, case women (women with CIN II/III, n = 12) had a significantly higher viral load than control women (women with CIN ≤ I, n = 47). This resulted in an increased relative risk of women with the 50% highest viral load for development of CIN II/III (OR 7.7; CI 1.6–33). In group B, women with CIN II/III (n = 38) had a significantly higher viral load than women with CIN ≤ I (n = 25). Women with the 50% highest viral load had an increased relative risk of CIN II/III (OR 3.2; CI 1.1–9.3) and a decreased chance of both viral clearance and cytologic regression. Our data suggest that in women with normal cytology an increased HPV 16 load confers an increased risk of developing a CIN lesion. A sustained high viral load is subsequently informative for progression to a high‐grade CIN lesion.

Chlamydia trachomatis and invasive cervical cancer: A pooled analysis of the IARC multicentric case‐control study

To determine whether Chlamydia trachomatis infection is consistently associated with an increased risk of invasive cervical carcinoma (ICC) after accounting for the strong effect of human papillomavirus (HPV) infection, a case‐control study of 1,238 cases of ICC and 1,100 control women from 7 countries was carried out (hospital‐based studies in Thailand, the Philippines, Morocco, Peru, Brazil and population‐based studies in Colombia and Spain, all coordinated by the International Agency for Research on Cancer, Lyon, France). C. trachomatis serum antibody detection was made by means of a microfluorescence assay. Among HPV DNA‐positive cases and controls, the risk of squamous cell ICC was elevated in C. trachomatis seropositive women (OR = 1.8; 95% CI = 1.2–2.7) after adjustment for age, center, oral contraceptive use, history of Pap smears, number of full‐term pregnancies and herpes simplex virus 2 seropositivity. The effect of C. trachomatis seropositivity on squamous cell ICC risk increased with increasing C. trachomatis antibody titers and was higher in women under 55 years of age. C. trachomatis antibodies were not associated with adeno‐ or adenosquamous cell carcinoma (OR = 1.0; 95% CI = 0.53–1.9) in HPV DNA‐positive women. An association of C. trachomatis with squamous cell ICC was found among all cases and control women with or without adjustment for HPV.

Human papillomavirus—the most significant risk determinant of cervical intraepithelial neoplasia

Sexual behavior has been consistently identified as a major risk factor for cervical cancer. Population‐based studies have demonstrated that risk related to sexual activity is mediated by human papillomavirus (HPV) infection. We conducted a case‐control study of 199 cases with low‐grade squamous intraepithelial lesions or high‐grade squamous intraepithelial lesions as defined by cytology and 1000 control women selected from an ongoing prospective cohort study in Copenhagen, Denmark. Furthermore, 131 women with equivocal smears (atypical squamous cells of undetermined significance) were examined as a separate borderline case group. At enrollment, all women had a personal interview and a gynecological examination including cervical swabs for HPV testing and a Pap smear. HPV testing was performed using a combination of general primer 5/6‐mediated and type‐specific polymerase‐chain‐reaction‐based methods. Cervical HPV infection was by far the most significant risk factor for cervical squamous intraepithelial lesions. The relationship with HPV was observed for all grades, while strength of association was greater for more severe lesions. The importance of the previously identified epidemiological risk factors for cervical neoplasia was also demonstrated. However, most of the effect of these factors could be explained by taking HPV infection into account, except for schooling and smoking. Non‐use of barrier contraceptives and smoking were the only significant risk factors in HPV‐positive women. In HPV‐negative women, a residual effect existed for different measures of sexual activity, and use of oral contraceptives and smoking constituted significant risk determinants. Overall, 66% of cases could be attributed to HPV; however, if the results were restricted to histologically confirmed high‐grade lesions, the proportion of cases that could be attributed to HPV infection increased to 80%.

Cytological regression and clearance of high-risk human papillomavirus in women with an abnormal cervical smear.

We studied the natural course of high-risk human papillomavirus (HPV) infection and cytological regression in women referred for colposcopy because of abnormal cervical smears. We found that high-risk HPV clearance preceded regression of cervical lesions by an average of 3 months. The cumulative 1-year rate of cytological regression was similar in women with mild and moderate dyskaryotic cervical smears. Thus, retesting of high-risk HPV after 6 months in women with mild to moderate dyskaryosis predicts cytological regression.

The Natural Course of Chlamydia trachomatis Infection in Asymptomatic Colombian Women: A 5-Year Follow-Up Study

The natural course of Chlamydia trachomatis infection and its risk factors were studied in Colombian women with normal cytological results, during a 5-year period. Eighty-two women who were found to be positive for C. trachomatis at the start of the study were studied at 6-month intervals. At each visit, a cervical scrape sample was obtained for detection of C. trachomatis by use of C. trachomatis endogenous-plasmid polymerase chain reaction (PCR)-enzyme immunoassay and VD2-PCR-reverse line blot assay. Of the women studied, 67% had a single-serovar infection, 10% had a mixed-serovar infection, and 23% had an infection with an unidentified type. An inversed rate of clearance of C. trachomatis infection was observed with oral contraceptive use (hazard ratio [HR], 1.7 [95% confidence interval {CI}, 1.1-2.7]) and first sexual intercourse at >/=20 years of age (HR, 4.3 [95% CI, 2.3-8.0]). Serovars of group B (B, D, and E) and C (H, I, J, and K) had a decreased rate of clearance (rate ratio, 0.4 [95% CI, 0.1-0.9]), compared with that for serovars of the intermediate group (F and G). At 4 years of follow-up, 94% of the women had cleared their infections.

The natural course of asymptomatic Chlamydia trachomatis infections: 45% clearance and no development of clinical PID after one-year follow-up

The natural course of asymptomatic Chlamydia trachomatis infections in women was studied during one year in a cohort based nested case-control study. Healthy women (n = 744, from four company health services in Amsterdam) with a medical check-up prior to job engagement were included. C. trachomatis-positive women (n = 30, cases) and a randomly selected control group of C. trachomatis-negative women (n = 186, controls) were followed for one year. Urine specimens (at one, six and 12 months) were analysed for the presence of C. trachomatis-DNA and the C. trachomatis-serovars, and questionnaires were filled in. The C trachomatis prevalence and natural course in relation to demographic and sexual characteristics after one, six and 12 months were studied. The main outcome measures were 1) the prevalence of C. trachomatis using urine specimens; 2) self-reported complaints; 3) clinical symptoms reported to the coordinating physicians. The prevalence of asymptomatic C. trachomatis infections was 4% and there was no correlation with demographic and sexual characteristics. The person/year clearance rate was 44.7% per year. None of the C. trachomatis-positive women developed clinical symptoms or used C. trachomatis specific antibiotic treatment. Women with or without an asymptomatic infection had the same number of self-reported urogenital complaints during follow-up. In persisting infections twice as many C. trachomatis-serovar E infections were detected as compared to clearing infections. Our findings showed that almost half of the asymptomatic C. trachomatis infections in women cleared during one year of follow-up and none developed clinical pelvic inflammatory disease (PID), which is a much lower figure than previously suggested. Therefore these data are important for cost effectiveness calculations in screening programmes for asymptomatic C. trachomatis infections.

The Absolute Risk of Cervical Abnormalities in High-risk Human Papillomavirus–Positive, Cytologically Normal Women Over a 10-Year Period

In spite of the success of cervical cytology as a cancer-screening tool, it has important limitations, and human papillomavirus (HPV) testing may be valuable in future screening. The majority of women in screened populations, who test HPV positive, will have a concurrent normal smear, and we need more information about the risk for subsequent high-grade cervical lesions in these women. We examined 8,656 younger women (22-32 years old) and 1,578 older women (40-50 years old) who were followed for development of cervical neoplasia (cytology and/or histology) through the Danish Pathology Data Bank. We estimated the proportion of women developing cervical lesions of different types before a given time point as a function of time. Among women with normal cytology and positive high-risk Hybrid Capture 2 (HC2) test, 17.7% and 24.5% of younger and older women, respectively, had a subsequent abnormal Pap smear within 5 years. The risk of CIN3 or cancer within 10 years among younger women with positive HC2 test was 13.6% (10.9-16.2) and 21.2% (2.7-36.1) among older women. An analysis among younger women also being HC2-positive 2 years before baseline showed a subsequent 10-year risk of > or =CIN3 of 18% (14.6-21.5). Among older women where HPV may be added to general screening, the estimated absolute risk of > or =CIN3 in HC2-positive women was more than 20% within 10 years. These results indicate that even a single positive HPV test in cytologically negative women is substantially predictive of high-grade CIN and suggest that HC2 testing can help stratify women into different risk categories.