Human papillomavirus infection and other risk factors for cervical intraepithelial neoplasia in Japan

Genotype prevalence and age distribution of human papillomavirus from infection to cervical cancer in Japanese women: A systematic review and meta-analysis

BACKGROUND

National HPV vaccination coverage in Japan is less than one percent of the eligible population and cervical cancer incidence and mortality are increasing. This systematic review and meta-analysis aimed to provide a comprehensive estimate of HPV genotype prevalence for Japan.

METHODS

English and Japanese databases were searched to March 2021 for research reporting HPV genotypes in cytology and histology samples from Japanese women. Summary estimates were calculated by disease stage from cytology only assessment - Normal, ASCUS, LSIL, HSIL and from histological assessment - CIN1, CIN2, CIN3/AIS, ICC (ICC-SCC, and ICC-ADC), and other. A random-effects meta-analysis was used to calculate summary prevalence estimates of any-HPV, high-risk (HR) and low-risk (LR) vaccine types, and vaccine genotypes (bivalent, quadrivalent, or nonavalent). This study was registered with PROSPERO: CRD42018117596.

RESULTS

A total of 57759 women with normal cytology, 1766 ASCUS, 3764 LSIL, 2017 HSIL, 3130 CIN1, 1219 CIN2, 869 CIN3/AIS, and 4306 ICC (which included 1032 ICC-SCC, and 638 ICC-ADC) were tested for HPV. The summary estimate of any-HPV genotype in women with normal cytology was 15·6% (95% CI: 12·3-19·4) and in invasive cervical cancer (ICC) was 85·6% (80·7-89·8). The prevalence of HR-HPV was 86·0% (95% CI: 73·9-94·9) for cytological cases of HSIL, 76·9% (52·1-94·7) for histological cases of CIN3/AIS, and 75·7% (68·0-82·6) for ICC. In women with ICC, the summary prevalence of bivalent vaccine genotypes was 58·5% (95% CI: 52·1-64·9), for quadrivalent genotypes was 58·6% (52·2-64·9) and for nonavalent genotypes was 71·5% (64·9-77·6), and of ICC cases that were HPV positive over 90% of infections are nonavalent vaccine preventable. There was considerable heterogeneity in all HPV summary estimates and for ICC, this heterogeneity was not explained by variability in study design, sample type, HPV assay type, or HPV DNA detection method, although studies published in the 1990s had lower prevalence estimates of any-HPV and HR HPV genotypes.

INTERPRETATIONS

HPV prevalence is high among Japanese women. The nonavalent vaccine is likely to have the greatest impact on reducing cervical cancer incidence and mortality in Japan.

Human Papillomavirus, Smoking, and Cancer

Background:

The effect of smoking on human papillomavirus (HPV) activity and subsequent dysplasia and neoplasia remains controversial

Objective:

To determine any reported effects of smoking on either HPV activity or HPV-related dysplasia/cancer using retrospective analysis of the literature from 1966 through 1998 via Toxline and PubMed to search for “smoking,” “papillomavirus,” and “cancer.”

Conclusion:

Several recent large studies demonstrated that smoking was associated with a greater incidence of cervical, vulvar, penile, anal, oral, and head and neck cancer in a dose-dependent fashion, while other studies did not show any correlation between smoking and cervical dysplasia after multivariate adjustment. Recent studies have also indicated that smoking may be more closely related to high-grade lesions of the cervix and vulva. These data provide evidence of an association between HPV, smoking, and cancer. Progression of dysplasia likewise seems to be associated with smoking. Several groups have attempted to discern whether the connection between smoking and cervical cancer is from local immunosuppression and/or from direct carcinogenic effects.

Human papillomavirus detection in pregnant women: a prospective matched cohort study

OBJECTIVE

To study the prevalence, incidence, and clearance of human papillomavirus (HPV) in pregnant and nonpregnant women.

METHODS

In this prospective matched cohort study, 51 women, became pregnant during follow-up of an HPV epidemiology study (n=2065), and 51 matched nonpregnant women were included. All women provided 3-monthly cervicovaginal self-samples and completed a questionnaire. The PCR SPF(10) LiPA(25) was used for HPV testing. Matching was performed using a propensity score.

RESULTS

The cumulative prevalence of high-risk HPV (hrHPV) was 19.6% (n=10) of the pregnant and 17.6% (n=9) of the matched control women. The time point prevalence of any type HPV and hrHPV was not significantly different for pregnant and matched control women. After baseline, there were 10 newly detected hrHPV types in 6 (11.8%) of the pregnant women, and there were 11 newly detected hrHPV types in 8 (15.7%) of the matched control women. There was no difference in HPV clearance between pregnant and matched control women.

CONCLUSIONS

This study shows that in a low-parity population of young, unscreened women, pregnancy does not seem to influence HPV prevalence, incidence, and clearance.

Genotype distribution of human papillomaviruses in Japanese women with abnormal cervical cytology

We report the prevalence and genotype distribution of human papillomaviruses (HPVs) among Japanese women with abnormal cervical cytology using the PGMY-CHUV assay, one of PGMY-PCR-based lineblot assays that was validated and shown to be suitable for the detection of multiple HPV types in a specimen with minimum bias. Total DNA was extracted from cervical exfoliated cells collected from 326 outpatients with abnormal Pap smears. Overall, 307 specimens (94%) were HPV-positive, 30% of which contained multiple genotypes. The prevalence of HPV DNA was 83% (49/59 samples) in atypical squamous cells of undetermined significance (ASC-US); 91% (20/22 samples) in atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion (ASC-H); 97% (130/134 samples) in low-grade squamous intraepithelial lesion (LSIL); and 99% (85/86 samples) in high-grade squamous intraepithelial lesion (HSIL). Three most frequent HPV types detected in HSIL were HPV16 (36%), HPV52 (24%), and HPV58 (14%). Our results suggest that multiple HPV infections are more prevalent in Japanese women than previously reported, and confirm that HPV52 and 58 are more dominant in their cervical precancerous lesions when compared to those reported in Western countries.

Incidence risk of cervical intraepithelial neoplasia 3 or more severe lesions is a function of human papillomavirus genotypes and severity of cytological and histological abnormalities in adult Japanese women

We examined incidence probabilities of cervical intraepithelial neoplasia 3 (CIN3) or more severe lesions (CIN3+) in 1,467 adult Japanese women with abnormal cytology in relation to seven common human papillomavirus (HPV) infections (16/18/31/33/35/52/58) between April 2000 and March 2008. Sixty-seven patients with multiple HPV infection were excluded from the risk factor analysis. Incidence of CIN3+ in 1,400 patients including 68 with ASCUS, 969 with low grade squamous intraepithelial lesion (LSIL), 132 with HSIL without histology-proven CIN2 (HSIL/CIN2(-)) and 231 with HSIL with histology-proven CIN2 (HSIL/CIN2(+)) was investigated. In both high grade squamous intraepithelial lesion (HSIL)/CIN2(-) and HSIL/CIN2(+), HPV16/18/33 was associated with a significantly earlier and higher incidence of CIN3+ than HPV31/35/52/58 (p = 0.049 and p = 0.0060, respectively). This association was also observed in LSIL (p = 0.0002). The 1-year cumulative incidence rate (CIR) of CIN3+ in HSIL/CIN2(-) and HSIL/CIN2(+) according to HPV genotypes (16/18/33 vs. 31/35/52/58) were 27.1% vs. 7.5% and 46.6% vs. 19.2%, respectively. In contrast, progression of HSIL/CIN2(+) to CIN3+ was infrequent when HPV DNA was undetected: 0% of 1-year CIR and 8.1% of 5-year CIR. All cervical cancer occurred in HSIL cases of seven high-risk HPVs (11/198) but not in cases of other HPV or undetectable/negative-HPV (0/165) (p = 0.0013). In conclusion, incidence of CIN3+ depends on HPV genotypes, severity of cytological abnormalities and histology of CIN2. HSIL/CIN2(+) associated with HPV16/18/33 may justify early therapeutic intervention, while HSIL/CIN2(-) harboring these HPV genotypes needs close observation to detect incidence of CIN3+. A therapeutic intervention is not indicated for CIN2 without HPV DNA.

Factors Affecting the Clearance of High-Risk Human Papillomavirus Infection and the Progression of Cervical Intraepithelial Neoplasia

OBJECTIVE: This study aimed to identify factors that predict clearance of high-risk human papillomavirus (HPV) infection and progression to cervical intraepithelial neoplasia (CIN) 2 or higher, in women with normal cervical histology or CIN 1. METHODS: A retrospective analysis was performed on 817 high-risk HPV-infected women with histologically verified CIN 1 or normal cervical histology. Patients were followed-up for a maximum of 24 months. Cervical HPV DNA tests were performed at every visit. RESULTS: At the end of follow-up, 648/817 (79.3%) patients were free from HPV infection and 66/817 patients (8.1%) progressed to CIN 2 or higher. Age, parity, cytology and viral load at diagnosis were significantly and inversely associated with HPV clearance. Cytology, viral load and presence of CIN 1 lesions were significantly associated with lesion progression. CONCLUSIONS: Cytology and high-risk HPV viral load may be useful markers for the likelihood of high-risk HPV clearance and lesion progression. Histological status, parity and marital status may also be useful factors to consider when predicting progression.

Biased amplification of human papillomavirus DNA in specimens containing multiple human papillomavirus types by PCR with consensus primers

Genotyping human papillomavirus (HPV) in clinical specimens is important because each HPV type has different oncogenic potential. Amplification of HPV DNA by PCR with the consensus primers that are derived from the consensus sequences of the L1 gene has been used widely for the genotyping. As recent studies have shown that the cervical specimens often contain HPV of multiple types, it is necessary to confirm whether the PCR with the consensus primers amplifies multiple types of HPV DNA without bias. We amplified HPV DNA in the test samples by PCR with three commonly used consensus primer pairs (L1C1/L1C2+C2M, MY09/11, and GP5+/6+), and the resultant amplicons were identified by hybridization with type-specific probes on a nylon membrane. L1C1/L1C2+C2M showed a higher sensitivity than the other primers, as defined by the ability to detect HPV DNA, on test samples containing serially diluted one of HPV16, 18, 51, 52, and 58 plasmids. L1C1/L1C2+C2M failed to amplify HPV16 in the mixed test samples containing HPV16, and either 18 or 51. The three consensus primers frequently caused incorrect genotyping in the selected clinical specimens containing HPV16 and one or two of HPV18, 31, 51, 52, and 58. The data indicate that PCR with consensus primers is not suitable for genotyping HPV in specimens containing multiple HPV types, and suggest that the genotyping data obtained by such a method should be carefully interpreted.

Human papillomavirus types 52 and 58 are prevalent in uterine cervical squamous lesions from Japanese women

Objective. To estimate the prevalence and genotypes of high-risk human papillomavirus (HPV) focusing HPV 16, 18, 52, and 58 in Japan. Methods. Liquid-base cytology specimens were collected from Japanese women (n = 11022), aged 14-98. After classifying cytodiagnosis, specimens were analyzed for HPV DNA by the multiplex polymerase chain reaction method, where 1195 specimens were positive for cervical smear, except adenomatous lesions. Result. HPV genotypes were detected in 9.5% of NILM and 72.2% of ASC-US or more cervical lesions. In positive cervical smears, HPV genotypes were HPV 52 at 26.6%, HPV 16 at 25.2%, HPV 58 at 21.8%, and HPV 18 at 7.1%. Most patients infected with HPV 16 were between 20-29 years old, decreasing with age thereafter. As for HPV 52 and 58, although the detection rate was high in 30- to 39-year-olds, it also was significant in the 50s and 60s age groups. Conclusion. In Japan, as a cause of abnormal cervical cytology, HPV52 and 58 are detected frequently in addition to HPV 16. In older age groups, HPV 52 and 58 detection rates were higher than that observed for HPV 16. After widespread current HPV vaccination, we still must be aware of HPV 52 and 58 infections.

Chlamydia trachomatis and risk of prevalent and incident cervical premalignancy in a population-based cohort

BACKGROUND

Cofactors might affect the risk of the rare progression from infection with carcinogenic human papillomavirus (HPV) to cervical premalignancy to invasive cancer. Some studies have observed that Chlamydia trachomatis infection is associated with increased risk for cervical cancer. In a large prospective cohort, we assessed the role of C trachomatis in cervical premalignancy and addressed confounding by HPV.

METHODS

We identified 182 women with prevalent and 132 women with incident histological cervical intraepithelial neoplasia grade 2 (CIN2), grade 3 (CIN3), or cervical cancer (CIN2+) in the Costa Rica HPV Natural History Study. Control subjects were 995 (approximately 10% of the 10 049) subjects who were randomly selected from the same study. Cervical HPV status at enrollment was determined by MY09/MY11 polymerase chain reaction amplification and dot-blot hybridization. The presence of C trachomatis DNA in cervical exfoliated cells at enrollment was determined by a novel serovar-specific polymerase chain reaction-based C trachomatis detection and genotyping assay. Plasma drawn at enrollment from each subject was used to determine C trachomatis immunoglobulin G (IgG) status. Logistic regression was used to examine the association between C trachomatis and CIN2+, taking into account possible confounding by HPV.

RESULTS

C trachomatis positivity at enrollment was associated with CIN2+ and concurrent and subsequent carcinogenic HPV infection. To account for confounding by HPV status, we restricted the analysis to women positive for carcinogenic HPV DNA at enrollment and found no association between C trachomatis status (as assessed by DNA or IgG) at enrollment and combined prevalent and/or incident CIN2+ (for C trachomatis DNA positivity, odds ratio = 0.77, 95% confidence interval = 0.42 to 1.41; for C trachomatis seropositivity, odds ratio = 1.09, 95% confidence interval = 0.85 to 1.41).

CONCLUSIONS

We found no association between C trachomatis status, as assessed by DNA or IgG, and risk of cervical premalignancy, after controlling for carcinogenic HPV-positive status. Previous positive associations between C trachomatis and cervical premalignancy could have been caused, in part, by an increased susceptibility to HPV infection.

Tobacco smoking and regression of low-grade cervical abnormalities

The role of tobacco smoking in the multistage carcinogenesis at the cervix is not fully understood because of a paucity of prospective data. To assess the relationship between smoking and spontaneous regression of cervical precursor lesions, a total of 516 women with low-grade squamous intraepithelial lesion (LSIL) were monitored by cytology and colposcopy every 4 months. Probability of LSIL regression within 2 years was analyzed in relation to smoking behaviors, with regression defined as at least two consecutive negative Pap smears and normal colposcopy. Women's age, initial biopsy results, and human papillomavirus (HPV) genotypes were included in the multivariate models for adjustments. Our study subjects included 258 never-smokers and 258 smokers (179 current and 79 former smokers). During a mean follow-up time of 39.8 months, 320 lesions regressed to normal cytology. Probability of regression within 2 years was significantly lower in smokers than in never-smokers (55.0%vs 68.8%, P = 0.004). The risk of LSIL persistence increased with smoking intensity and duration and with younger age at starting smoking (P = 0.003, P < 0.001, and P = 0.03, respectively). Smokers had twice as high a risk of persistent HPV infection compared to never-smokers (odds ratio, 2.50; 95% confidence interval, 1.30-4.81; P = 0.006). In young women, passive smoking since childhood reduced probability of regression within 2 years (56.7%vs 85.9%, P < 0.001). Further adjustments for a wide range of cervical cancer risk factors did not change the findings. In conclusion, tobacco smoking may interfere with regression of cervical precursor lesions. Childhood exposure to second-hand smoke may increase a risk of persistent cervical abnormalities among young women.

Human papillomavirus infections among Japanese women: age-related prevalence and type-specific risk for cervical cancer

To obtain baseline data for human papillomavirus (HPV) screening and vaccination in Japan, we analyzed HPV DNA data from 2282 Japanese women (1517 normal cytology, 318 cervical intraepithelial neoplasia [CIN] grade 1, 307 CIN2-3, and 140 invasive cervical cancer [ICC]) that visited the University of Tsukuba Hospital or Ibaraki Seinan Medical Center Hospital for screening or treatment of cervical diseases between 1999 and 2007. An L1-based PCR method was used for individual HPV genotyping. The most common HPV types in ICC were, in order of decreasing prevalence, HPV16 (40.5%), HPV18 (24.4%), HPV52 (8.4%), HPV58 (3.1%), and HPV33 (3.1%). Based on the comparison of HPV type distributions between normal cytology and CIN2-3 and ICC, estimated risk of disease progression varied considerably by genotype: HPV16, HPV18, HPV31, HPV33, HPV35, HPV52, and HPV58 (prevalence ratio, 1.92; 95% confidence interval 1.58-2.34); other oncogenic types (0.31, 95% confidence interval 0.19-0.50); and non-oncogenic types (0.09, 95% confidence interval 0.03-0.43). HPV16 and/or HPV18, including coinfections with other types, contributed to 67.1% of ICC and 36.2% of CIN2-3 among Japanese women. More importantly, the overall prevalence of HPV16 and/or HPV18 varied greatly according to the women's age: highest in women aged 20-29 years (ICC, 90.0%; CIN2-3, 53.9%), decreasing with age thereafter, and lowest in women aged 60 years or older (ICC, 56.3%; CIN2-3, 25.0%). In conclusion, type-specific HPV testing may help identify Japanese women at high risk of progression to CIN2-3 and cancer. In Japan, current HPV vaccines are estimated to provide approximately 70% protection against ICC and may be more useful in reducing the incidence of cervical cancer and precancer in young women of reproductive age.

A Joinpoint regression analysis of long-term trends in cancer mortality in Japan (1958-2004)

Cancer is one of the major targets of disease control programs in Japan. A Joinpoint regression model was used to analyze the long-term trends of mortality related to overall cancer and the 15 most common cancers based on published data from the National Vital Statistics of Japan between 1958 and 2004. Since 1996, a decline has been seen in overall cancer for both sexes in Japan. Most of the common sites, including cancers of the stomach, colon, liver, gallbladder and lung and leukemia in both sexes, cancer of esophagus in men and rectal and ovarian cancers in women showed a decreasing trend, and cancers of the rectum, pancreas, prostate and urinary bladder and malignant lymphoma in men and cancers of the esophagus and uterus in women leveled off during the most recent period. However, an increasing trend was confirmed for cancers of the pancreas, breast and urinary bladder and malignant lymphoma in women. An effective cancer control program including prevention, early detection and treatment should be implemented to further reduce the cancer mortality, particularly for cancer sites that show higher mortality rates or increasing trends.

Age-specific prevalence of infection with human papillomavirus in females: a global review

PURPOSE

Global data on age-specific prevalence of human papillomavirus (HPV) infection overall, and for high-risk HPV types 16 and 18, are essential for the future implementation of HPV prophylactic vaccines for cervical cancer prevention.

METHODS

A systematic review of peer-reviewed publications was conducted to summarize worldwide data on genital HPV-DNA prevalence in women. Studies with clear descriptions of polymerase chain reaction or hybrid capture detection assays were included.

RESULTS

A total of 346,160 women were included in 375 studies. Of 134 studies with age-stratified HPV prevalence data (116 low sexual risk populations, 18 high sexual risk populations), over 50% were from Europe and the Middle East (38%) and North America (19%), with smaller proportions from Asia and Australia (21%), Central and South America (11%), and Africa (10%). Across all geographical regions, data on HPV prevalence were generally limited to women over 18 years of age. Consistently across studies, HPV infection prevalence decreased with increasing age from a peak prevalence in younger women (< or =25 years of age). In middle-aged women (35-50 years), maximum HPV prevalence differed across geographical regions: Africa (approximately 20%), Asia/Australia (approximately 15%), Central and South America (approximately 20%), North America (approximately 20%), Southern Europe/Middle East (approximately 15%), and Northern Europe (approximately 15%). Inconsistent trends in HPV prevalence by age were noted in older women, with a decrease or plateau of HPV prevalence in older ages in most studies, whereas others showed an increase of HPV prevalence in older ages. Similar trends of HPV 16 and/or 18 prevalence by age were noted among 12 populations with available data.

DISCUSSION

Genital HPV infection in women is predominantly acquired in adolescence, and peak prevalence in middle-aged women appears to differ across geographical regions. Worldwide variations in HPV prevalence across age appear to largely reflect differences in sexual behavior across geographical regions. Further studies of HPV prevalence in adolescents are needed for all geographic regions.

Human papillomavirus type distribution in women from Asia: a meta-analysis

The aim of this study was to determine human papillomavirus (HPV) type distribution in women with and without cervical neoplasia from Asia and to estimate the potential future impact of an HPV 16/18 prophylactic vaccine in this region. A meta-analysis was conducted including 79 studies using polymerase chain reaction to detect HPV types. A total of 5954, 1653, 958, and 16,803 women with invasive cervical cancer (ICC), high-grade squamous intraepithelial lesions (HSIL), low-grade squamous intraepithelial lesions (LSIL), and normal cytology or histology were included, respectively. Type-specific prevalence of HPV types 6, 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, 68, 70, 73, and 82 were estimated and stratified by cervical lesion grade. Overall HPV prevalence was 85.9%, 81.0%, 72.9%, and 14.4%, respectively, in women with ICC, HSIL, LSIL, and normal cytology/histology. In ICC, HPV 16 was the predominant type (52.4%), followed by HPV 18, 58, 33, 52, 45, 31, and 35. The estimated HPV 16/18-positive fraction was 66.9%, 40.4%, 26.7%, and 3.3% in women with ICC, HSIL, LSIL, and normal cytology or histology, respectively. In ICC, the estimated HPV 16/18-positive fraction was about 70% in all Asian geographic regions, with the exception of Japan (51.3%). HPV 16/18 vaccines are estimated to provide about 67% protection against ICC in Asia. HPV 58 and 52 were among the five most common types in ICC in eastern and southeastern Asia but not in south central Asia. After HPV 16 and 18, the next most six common HPV types were 58, 33, 52, 45, 31, and 35 that accounted for additional 20% of cervical cancer cases in Asia. For optimal population coverage, these HPV carcinogenic types should be considered for second-generation HPV prophylactic vaccines.

Risk factors for the progression or persistence of untreated mild dysplasia of the uterine cervix

To identify the factors that may predict the progression or persistence of untreated mild dysplasia of the uterine cervix, we performed a retrospective review of 118 patients with histologically verified mild dysplasia who underwent colposcopic biopsies between January 1999 and December 2003. Regression to normal occurred in 70.3%, progression to moderate dysplasia or worse occurred in 11.0%, and persistence of mild dysplasia occurred in 18.7%. In regression/progression analysis, progression of untreated mild dysplasia was 34.5% (10/29) in patients with high viral loads (> or =100 relative light units/positive control [RLU/PC]) and 4.5% (3/67) in those with low viral loads (1 to <100 RLU/PC) and negative human papillomavirus (HPV) tests (P < 0.001). Women with high viral loads had a 13-fold greater chance of progression of untreated mild dysplasia than those with low viral loads and negative HPV tests (CI: 2.494-95.297; P = 0.0022). Those associated with both positive smear and positive HPV test (12/45 = 26.7%) were at a greater risk of progression of untreated mild dysplasia as compared with those with positive smear and negative HPV (0/17 = 0.0%) or those with negative smear and positive HPV test (1/18 = 5.6%). Those with high viral loads and both with positive smear and positive HPV test should be followed closely because of their increased risk of progression of untreated mild dysplasia.

IgG antibodies to HPV16, 52, 58 and 6 L1-capsids and spontaneous regression of cervical intraepithelial neoplasia

To identify the predictive markers for spontaneous regression of cervical intraepithelial neoplasia (CIN), we examined whether IgG antibody responses to common human papillomavirus (HPV) L1-capsids correlate with CIN regression. In a cohort study, a total of 116 Japanese women with CIN grade I/II were tested for cervical HPV DNA and serum IgG antibodies to HPV16/52/58/6 L1-capsids. Our data suggest that baseline IgG reactivities to HPV L1-capsids do not serve as a predictive marker of CIN regression, in contrast to histological CIN grades and HPV DNA status.

Dominant human papillomavirus 16 infection in cervical neoplasia in young Japanese women; study of 881 outpatients

OBJECTIVE

Human papillomavirus (HPV) infection is reported to be related to carcinogenesis in the uterine cervix. In Japan, screening for cervical cancer by cytology is performed in women over 30 years old. The purpose of this study was to determine whether there is an association between patient age and cervical neoplasia or HPV infection in Japanese women.

METHODS

Specimens from 881 randomly selected patients who came to our clinic were tested for HPV DNA by using Hybrid Capture II, whereas specimens from a 204-patient randomly selected subset diagnosed with cervical neoplasia were tested for HPV DNA by using polymerase chain reaction (PCR). HPV typing was performed in all the PCR-positive cases.

RESULTS

The HPV-positive rate in the 20- to 29-year-old patients (29.0% in the normal cytology/histology group and 85.5% in the abnormal group) was higher than in the 30- to 59-year-old patients, and the rate declined until age 60 when age increased. While HPV 18, HPV 52, other HPV types, and HPV types as a whole were frequently detected in 30- to 49-year-old patients, HPV 16 was detected more frequently in the younger group than the other HPV types (P = 0.03). Among the HPV 16-positive patients with cervical neoplasia, the proportion of cervical intraepithelial neoplasia (CIN) 3 cases was high (44%) in the 20- to 29-year-old group.

CONCLUSIONS

Screening for cervical neoplasia by cytology should also be performed in women under 30 years old in Japan. The HPV typing could be a tool to strictly follow-up younger women who were diagnosed with CIN.

Prostitution and other cofactors in preinvasive and invasive lesions of the cervix

OBJECTIVE

To examine risk factors for preinvasive and invasive lesions of the cervix in Venezuelan female sex workers (FSW).

METHODS

A total of 438 FSW were analysed. Each FSW had their clinical history recorded, a gynaecological examination, a Pap smear and a colposcopic examination of the cervix. A cervical biopsy was taken under colposcopic guidance when there was an abnormal epithelium. The statistical methods used were Student's t-test, chi(2) test and logistic regression.

RESULTS

The sex workers' mean age was 32.1 +/- 7.9 years old (mean +/- standard deviation). The age of the first sexual intercourse activity for the FSW was 15.9 +/- 2.1 years. Sixty-four of the 84 women (76.2%) who had cervical biopsies had preinvasive and invasive lesions; 41 (9.4%) had cervical intra-epithelial neoplasia (CIN) 1, 12 (2.7%) had CIN 2, eight (1.8%) had CIN 3, two (0.5%) had microinvasive carcinoma, and one (0.2%) had invasive carcinoma. Forty of these 64 women (62.5%) with preinvasive or invasive lesions had a concurrent histological diagnosis of human papilloma virus (HPV) infection (P < 0.0001). The FSW with cervical pathology were younger (P < 0.05) and had their first sexual intercourse earlier (P < 0.02) than FSW with no pathology. Two hundred and seventy-six (63%) of the FSW were current smokers, and 47 of these women (17.6%) had cervical pathology (P < 0.03).

CONCLUSIONS

First sexual experience before 20 years of age, cigarette smoking and HPV infection were high-risk factors for preinvasive and invasive lesions of the cervix in Venezuelan FSW.

Cervical Cytologic Examination During Physical Checkup of Pregnant Women: Cervical Cancer Screening in Women Under the Age of Thirty

Recently, the Ministry of Health, Labor and Welfare proposed that cervical cancer screening should be conducted for women aged 20 to 29 years old in Japan. However, there are insufficient data available in Japan concerning the screening conducted for women under the age of 30. Therefore, we made a survey of the results of cervical cytologic examination for pregnant women. 28,616 pregnant women were examined as subjects of a study group. A group of 108,289 women, subjected to group screening for cervical cancer in Miyagi Prefecture, were studied as a control group. The rate of subjects who required close examination in the pregnant women's group was significantly higher than that in the mass screening group (1.12% vs. 0.84%). The rate of close examination was significantly higher in the women 19 years old or younger compared to those in the age group of 25 to 39 years old. The rate was also significantly higher in women aged 20 to 24 years old than those who are 25 to 34 years old. Of the 321 subjects who required close examination, 34 cases underwent treatment, and 17 cases were under age 30. Moreover, all three cases of microinvasive and/or invasive carcinoma were under the age of 30 years (23, 23, 27 years old, respectively). Our results suggest that screening for cervical cancer in pregnancy is a useful means to find cervical neoplasia in young women and is effective in reducing the cervical cancer morbidity rate.

Are smoking and chlamydial infection risk factors for CIN? Different results after adjustment for HPV DNA and antibodies

To identify the risk factors for cervical intraepithelial neoplasia (CIN), we reanalysed the data from our previous case-control study by adjusting for human papillomavirus (HPV) antibodies. Unlike our previous study based only on HPV DNA, smoking and Chlamydia trachomatis infection were revealed as significant risk factors for CIN after adjustment for HPV antibodies.

Association between high-risk human papillomavirus DNA load and precursor lesions of cervical cancer in Mexican women

OBJECTIVE

Our objective was to determine the association between viral load of high risk human papilloma virus (HPV) using the Hybrid Capture II (HC II) system and cervical intraepithelial neoplasia (CIN) lesion stage.

METHODS

A total of 182 consecutive women with confirmed diagnoses of CIN 1-3 and 182 healthy women with negative Pap were included. All subjects underwent structured interviews focused on socioeconomic and reproductive factors. HC II testing was used to detect human papilloma virus (HPV) DNA. Viral load was measured by light measurements expressed as relative lights unit (RLU) ratio (specimens/control). Log(10)RLU ratios were categorized for analysis into four groups: negative (</=0); low viral load (0.01-1.0), middle viral load (1.01-2.0), and high viral load (2.0-3.6). Frequencies and association measurement odds ratio (OR) adjusted by unconditional multinomial regression (UMR) were used in analysis.

RESULTS

A total of 75 of 80 (93.7%) patients with CIN 2-3, 82 of 101 (79.4%) with CIN 1, and 36 of 182 (19.8%) controls were positive for HPV DNA. The higher the viral load of HPV DNA infection observed, the higher the probability of being associated with stage of CIN (P <0.001). Association between low viral load HPV and CIN 1 was 16.8 (7.2-39) compared with the highest association observed with high viral load and CIN 2-3 (OR(a) = 365.8, 94.7-1412). Both control and cases in the oldest women presented the highest viral load.

CONCLUSIONS

We found high frequencies of HPV DNA in CIN 1 and in CIN 2-3 patients. A clear association between viral load of HPV DNA was determined by HC II assay and CIN stage.

Papanicolaou tests and molecular analyses using new fluid-based specimen collection technology in 3000 Japanese women

A fluid-based Papanicolaou test has been established to improve sample collection and preparation. This study was the first large-scale investigation in Japan to examine the feasibility of using fluid-based Papanicolaou specimens to detect human papillomavirus (HPV) using Hybrid Capture II and polymerase chain reaction (PCR). Three thousand patients who visited Keio University Hospital between October 2000 and February 2001 were enrolled in the study. The results of the fluid-based Papanicolaou tests corresponded well with those of conventional Papanicolaou smears (96.8% concordance). The sensitivities of cervical neoplasia detection using the fluid-based Papanicolaou test (73.9%) and Hybrid Capture II (76.3%, P=0.55) were not significantly different. Among the cervical intraepithelial neoplasia 3 and squamous cell carcinoma specimens, HPV 16 and HPV 52 were predominantly detected using the PCR method. Although some DNA samples extracted from the fluid-based specimens were degradaded, PCR and direct sequencing could be performed without difficulty even after 1 year of specimen storage. We conclude that fluid-based Papanicolaou specimens can be applied to investigate HPV infection.

Prognostic factors associated with the clinical outcome of cervical intraepithelial neoplasia: a cohort study in Japan

One hundred and eighty-five Japanese women with cervical intraepithelial neoplasia (CIN) were enrolled in this follow-up study. On the basis of the prevalence of human papillomavirus (HPV) DNA in Japanese cervical cancer patients, HPV types were categorized into three groups as follows: (1) high risk (types 16, 18, 33, 52, and 58), (2) intermediate risk (types 31, 35, 39, 51, 56, 59, 68, and 70), (3) low risk (type 6, 30, 42, 53, 54, 55, 66 and unclassified types). High-risk HPV infection was a risk factor for progression of the disease. The regression rate in the HPV negative group was higher (83.3%) than those in the HPV positive groups, but the differences in regression were no longer significant after adjustment for age and CIN grade. It is also noted that a lower cytomegalovirus IgG level and a smaller number of past pregnancies might be associated with the regression of CIN lesions.

IgG antibodies to human papillomavirus 16, 52, 58, and 6 L1 capsids: case-control study of cervical intraepithelial neoplasia in Japan

In Japan, human papillomavirus (HPV) 16, 52, and 58 are most commonly associated with cervical intraepithelial neoplasia (CIN). By contrast, HPV6 is primarily associated with genital warts. This study was designed to evaluate the association between IgG antibody responses to common HPVs and the risk of CIN development within a Japanese population. CIN cases (n = 141) and controls (n = 109) were tested for cervical HPV DNA and serum IgG antibodies to L1 capsids of HPV16, 52, 58, and 6. Seropositivity to HPV16, 52, and 58 L1 capsids was significantly higher in CIN cases than in controls: 27%, 21%, and 31% versus 16%, 11%, and 11%, respectively (P < 0.05). HPV6 L1 seropositivity was not significantly associated with CIN lesions (P = 0.11). Presence of viral DNA for either HPV16, 52, or 58 correlated with a significant antibody response against the homologous L1 capsids but not heterologous L1 capsids. Furthermore, seropositivity to multiple types of HPV16, 52, and 58 was more strongly associated with an increased risk of CIN development than seropositivity to a single type (P for trend <0.001). These findings indicate that IgG antibodies to L1 capsids of HPV16, 52, and 58 represent an increased risk of CIN development, with antibodies to multiple types being indicative of a further increase in risk. The presence of CIN lesions in women with seropositivity to multiple types suggests that viral exposure to a given type may not be protective against infections by other types and subsequent CIN development.

Cigarette smoking and cervical cancer: Part I: a meta-analysis

Cancer of the cervix is the third most common cancer among women worldwide and its etiology is not clearly understood. Human papillomavirus can be found in approximately 95% of cervical cancers, but it does not appear to be necessary or sufficient to induce malignancy. In 1977, Winkelstein suggested that cigarette smoking was a causative factor in the development of cervical cancer. We report a meta-analysis of cigarette smoking and cervical disease and conclude that the data support a role for cigarette smoking as a risk factor for cervical cancer. We propose a multifactorial hypothesis involving a virus-tar interaction as the etiology of cervical cancer.

Serum carotenoids and vitamins and risk of cervical dysplasia from a case-control study in Japan

The relationships between risk of cervical dysplasia and dietary and serum carotenoids and vitamins were investigated in a case-control study. Cases were 156 women who attended Papanicolaou test screening in nine institutes affiliated with Japan Study Group of Human Papillomavirus (HPV) and Cervical Cancer and had cervical dysplasia newly histologically confirmed. Age-matched controls were selected from women with normal cervical cytology attending the same clinic. Blood sample and cervical exfoliated cells were obtained for measuring serum retinol, alpha-carotene, beta-carotene, zeaxanthin/lutein, cryptoxanthin, lycopene and alpha-tocopherol and for HPV detection. Higher serum level of alpha-carotene was significantly associated with decreased risk of cervical dysplasia after controlling for HPV infection and smoking status (odds ratio (OR) = 0.16, 95% confidence interval (CI) 0.04-0.62 for the highest as compared with the lowest tertile). Decreased risk for the highest tertile of serum lycopene (OR = 0.28) was marginally significant. Decreased risks observed for the highest tertiles of beta-carotene (OR = 0.65) and zeaxanthin/lutein (OR = 0.53), were not statistically significant.