Human papillomavirus infection in sexually active adolescent females: prevalence and risk factors

Managing sexually transmitted diseases in adolescents

Control of sexually transmitted diseases (STDs) in adolescents is a primary responsibility of health care providers. Using the tools of history and physical examination, and drawing on the awareness of different stages of adolescent development, health care providers can define at-risk for STDs. This article discusses screening practices, disease control through reporting and preventive counseling, and treatment guidelines for common STD syndromes.

Natural history of cervicovaginal papillomavirus infection in young women

BACKGROUND

Genital human papillomavirus (HPV) infection is highly prevalent in sexually active young women. However, precise risk factors for HPV infection and its incidence and duration are not well known.

METHODS

We followed 608 college women at six-month intervals for three years. At each visit, we collected information about lifestyle and sexual behavior and obtained cervicovaginal-lavage samples for the detection of HPV DNA by polymerase chain reaction and Southern blot hybridization. Pap smears were obtained annually.

RESULTS

The cumulative 36-month incidence of HPV infection was 43 percent (95 percent confidence interval, 36 to 49 percent). An increased risk of HPV infection was significantly associated with younger age, Hispanic ethnicity, black race, an increased number of vaginal-sex partners, high frequencies of vaginal sex and alcohol consumption, anal sex, and certain characteristics of partners (regular partners having an increased number of lifetime partners and not being in school). The median duration of new infections was 8 months (95 percent confidence interval, 7 to 10 months). The persistence of HPV for > or =6 months was related to older age, types of HPV associated with cervical cancer, and infection with multiple types of HPV but not with smoking. The risk of an abnormal Pap smear increased with persistent HPV infection, particularly with high-risk types (relative risk, 37.2; 95 percent confidence interval, 14.6 to 94.8).

CONCLUSIONS

The incidence of HPV infection in sexually active young college women is high. The short duration of most HPV infections in these women suggests that the associated cervical dysplasia should be managed conservatively.

The natural history of human papillomavirus infection as measured by repeated DNA testing in adolescent and young women

OBJECTIVES

The objectives of this study were to describe the early natural history of human papillomavirus (HPV) infection by examining a cohort of young women positive for an HPV test and to define within this cohort (1) the probability of HPV regression, (2) the risk of having a squamous intraepithelial lesion, and (3) factors that were associated with HPV regression.

STUDY DESIGN

The study was a cohort analytic design. An inception cohort of 618 women positive for HPV participated. HPV testing, cytologic evaluation, and colposcopic evaluation were performed at 4-month intervals. HPV testing was characterized for two groups: low risk (five types rarely associated with cancers) and high risk (nine types most commonly associated with cancers).

RESULTS

Estimates provided by Kaplan-Meier curves showed that approximately 70% of women were found to have HPV regression by 24 months. Women with low-risk HPV type infections were more likely to show HPV regression than were women with high-risk HPV type infections (log rank test p = 0.002). The relative risk for the development of high-grade squamous intraepithelial lesion (HSIL) was 14.1 (95% confidence interval: 2.3, 84.5) for women with at least three positive tests for high-risk HPV preceding the development of the HSIL compared with that for women with negative tests for high-risk HPV. However, 88% of women with persistent positive HPV tests have not had HSIL to date. No factors associated with high-risk HPV type regression were identified except for a negative association with an incident history of vulvar condyloma (relative risk = 0.5 [95% confidence interval: 0.3 to 0.8]).

CONCLUSION

Most young women with a positive HPV test will become negative within a 24-month period. Persistent positive tests with oncogenic HPV types represented a significant risk for the development of HSIL. However, we found that most young women with persistent positive HPV tests did not have cytologically perceptible HSIL over a 2-year period. Factors thought to be associated with the development of HSIL were found not to be important in HPV regression.

Infectious causes of chronic inflammatory diseases and cancer

Powerful diagnostic technology, plus the realization that organisms of otherwise unimpressive virulence can produce slowly progressive chronic disease with a wide spectrum of clinical manifestations and disease outcomes, has resulted in the discovery of new infectious agents and new concepts of infectious diseases. The demonstration that final outcome of infection is as much determined by the genetic background of the patient as by the genetic makeup of the infecting agent is indicating that a number of chronic diseases of unknown etiology are caused by one or more infectious agents. One well-known example is the discovery that stomach ulcers are due to Helicobacter pylori. Mycoplasmas may cause chronic lung disease in newborns and chronic asthma in adults, and Chlamydia pneumoniae, a recently identified common cause of acute respiratory infection, has been associated with atherosclerosis. A number of infectious agents that cause or contribute to neoplastic diseases in humans have been documented in the past 6 years. The association and causal role of infectious agents in chronic inflammatory diseases and cancer have major implications for public health, treatment, and prevention.

The pediatrician and the sexually active adolescent. A primer for sexually transmitted diseases

Sexual activity is a common practice among young adolescents, placing them at high risk for STDs, many of which have long-term consequences. Early diagnosis and treatment are essential to limit both the consequences and the spread of these infections. The clinician has a responsibility to the adolescent patient to recognize and treat these diseases. Using history and physical examination, the clinician should be able to determine an adolescent's risk for an STD, and, based on this risk, undertake the appropriate evaluations. Patient treatment, follow-up, and management of sex partners are then guided by the results of either presumptive or definitive diagnostic tests.

Adolescent girls' understanding of Papanicolaou smear results

STUDY OBJECTIVE

Human papillomavirus (HPV) urogenital infections are common in sexually active adolescents. Previous research has indicated that adolescent girls do not reliably report histories of HPV infection. This study examined whether asking an adolescent girl if she had ever had an abnormal Papanicolaou (PAP) smear was a good screening question for evidence of HPV urogenital infection.

DESIGN

The responses to the question about abnormal PAP smears, were compared with their charts for documented abnormal PAP smear, HPV infection, and sexually transmitted infection.

SETTING

An urban, hospital-based adolescent clinic.

PARTICIPANTS

Fifty adolescent girls (mean age, 14.8 years).

MAIN OUTCOME MEASURES

Degree of agreement (kappa statistic).

RESULTS

Using a kappa statistic, reported history of an abnormal PAP smear had "fair" agreement with documented dysplasia on PAP smear and "moderate" agreement with documented HPV infection (i.e., either condyloma on PAP smear or genital warts noted on examination). This reported history of an abnormal PAP smear agreed better with documented HPV infection than with documented dysplasia on PAP smear.

CONCLUSIONS

There appears to be considerable confusion among adolescent girls regarding their PAP smear results. Care providers need to be sensitive to this when they are collecting historical information and when they are diagnosing HPV infection or an abnormal PAP smear.

Follow-up of abnormal Papanicolaou smears in a hospital-based adolescent clinic

STUDY OBJECTIVE

To present data on the spectrum of abnormal Papanicolaou (PAP) smears in adolescents and to determine factors that influence compliance with recommendations to return for repeat PAP smears or for colposcopic examination.

DESIGN

Retrospective chart review with follow-up telephone calls to patients who did not follow recommendations for colposcopy.

SETTING

Adolescents receiving health care in a hospital-based adolescent clinic.

PARTICIPANTS

Patients with abnormal PAP smears between July 1, 1994 and June 30, 1995.

MAIN OUTCOME MEASURES

Compliance with follow-up for abnormal PAP smears including referral to the colposcopy clinic, and the results of repeat PAP smears and colposcopy.

RESULTS

Of 888 adolescents undergoing PAP smear evaluation 119 (13.4%) had an abnormal PAP smear during the study year (index PAP). The results of the index PAP were 97 (81.5%) atypia and 22 (18.5%) squamous intraepithelial lesion low grade (SIL LG). The index PAP was the first abnormal PAP smear for 92 of the patients (77%); 27 had one or more previous abnormal PAP smears (18 atypia, 7 SIL LG, 2 SIL high grade [HG]), and 13 had been referred for colposcopy in the past. For 76 of 92 patients with atypia on index PAP (84%), the index PAP was the first abnormal PAP smear. Of these 76 patients, 51 had a second PAP smear: 27 (53%) were normal, 13 (25%) atypia, and 11 (22%) SIL LG. Sixty patients were referred to the colposcopy clinic, but only 37 actually kept the colposcopy appointment despite outreach. The only significant factor for obtaining colposcopy was a visit to the Adolescent Clinic after notification of the abnormal PAP smear result and before the colposcopy appointment; 79% of those who had a visit obtained colposcopy compared with 45% of those who did not have such a visit (p = 0.007). There were no significant differences by race, insurance status, age, PAP smear result, previous referral for colposcopy, or number of reminders with compliance with recommendations for repeat PAP smears or colposcopy.

CONCLUSIONS

Although a sizable proportion of adolescents with abnormal PAP smears have significant pathology on repeat PAP smears, adolescents with abnormal PAP smears have a high failure rate in keeping appointments for follow-up PAP smears and colposcopy. Interventions that target all adolescents with abnormal PAP smears need to be designed and tested to aid follow-up.

Factors associated with human papillomavirus infection detected by polymerase chain reaction among urban Canadian aboriginal and non-aboriginal women

OBJECTIVES

To determine the prevalence and correlates of human papillomavirus (HPV) infection among women attending an ethnically mixed, predominantly low-income, inner-city primary care clinic.

STUDY DESIGN

Cross-sectional survey (N = 1,477). Demographic, behavioral, and reproductive history data were collected by questionnaire. Cervical swabs were analyzed for gonorrhea and chlamydial infections, abnormal cytology, and HPV infection assessed by PCR followed by hybridization for types 6, 11, 16, 18, 31, 33, and 35.

RESULTS

Human papillomavirus was detected in 33% of specimens, with no significant difference between Aboriginal (AB) and non-Aboriginal women. Adjusting for AB status, HPV infection was associated with marital status, condom use, number of sexual partners (last year and lifetime), age at first sexual intercourse, a history of sexual abuse, and current abnormal Papanicolaou (Pap) smear. In multivariate analyses excluding abnormal Pap smear as an independent variable, marital status and the number of lifetime sexual partners were found to be significant independent predictors of HPV infection. Comparing individuals with 20+ lifetime sexual partners and those with 1 or fewer partners, the odds ratio (OR) for HPV infection was 1.90 (95% confidence interval [CI] 1.66-2.17) among AB women and 1.54 among non-AB women (95% CI 1.36-1.73). The OR for infection with HPV types 6 and 11 was 1.39 (95% CI 1.22-1.58), whereas for the high oncogenic risk types of 16, 18, 31, 33, and 35, the OR was 1.82 (95% CI 1.65-2.01).

CONCLUSIONS

No differences were found between AB and non-AB women in the detection of HPV DNA, despite the higher risk for cervical cancer and the prevalence of recognized behavioral and reproductive risk factors among AB women. This study also indicates that the association of sexual activity with HPV infection holds true for both high- and low-oncogenic HPV types.

Seropositivity against HPV 16 capsids: a better marker of past sexual behaviour than presence of HPV DNA

OBJECTIVES

To assess if seropositivity to human papillomavirus type 16 capsids is a better marker of sexual history than the presence of HPV DNA.

STUDY DESIGN

A population based age stratified random sample of 234 Norwegian women (mean age 32.8 years, range 20-44) was examined for HPV serum antibodies, cervical HPV DNA, cytology and age in relation to sexual behaviour.

RESULTS

Neither age nor age at first sexual intercourse was associated with HPV 16 antibodies. Adjusted ORs for 4-5; 6-10 and > 10 versus 0-1 lifetime sexual partners, were 13.1 (95% CI 1.5-110.8), 8.2 (1.0-69.6) and 10.5 (1.2-94.0) for HPV 16 seropositivity, respectively; and 2.6 (0.2-27.8), 3.4 (0.4-31.7) and 4.1 (0.4-42.8) for HPV 16 DNA positivity, respectively.

CONCLUSION

Seropositivity to HPV 16 capsids is positively associated with the number of sexual partners, suggesting that HPV 16 is predominantly sexually transmitted. The fact that serology had a stronger association with number of sexual partners than viral DNA suggests that seroreactivity is a better measure of lifetime history of HPV infection.

Genital human papillomavirus infections: knowledge, perception of risk, and actual risk in a nonclinic population of young women

The purpose of this study was to assess knowledge, beliefs, and attitudes about genital human papillomavirus (HPV) infections in a group of young women in a nonclinic setting and to examine the association between perception of risk and actual risk. One hundred ten women attending a state university participated in the study and were asked to complete a self-administered questionnaire about knowledge and perceptions of risk. They were then offered testing for the virus using a self-administered vaginal method. The mean age was 20 +/- 1.2 years. Ninety (82%) were sexually experienced (SE), with a mean number of lifetime partners of 5.1 +/- 4.3. The mean knowledge score was less than the 68th percentile, reflecting low levels of knowledge about genital HPV infections. The SE group had a higher knowledge score than the sexually inexperienced (p < .02), but there were no differences in knowledge between those who chose to be tested and those who refused testing. The majority of women attributed negative emotion to being hypothetically tested positive for HPV. Emotions selected by > 50% of the group included feeling scared, angry, guilty, anxious, confused, dirty, regretful, and panicky. A greater negative emotion score was associated with refusing HPV testing (p < .002). Of the SE women, 58% (51) perceived themselves at risk, and, of this group, 71% (36) agreed to be tested. Of the women who agreed to HPV testing, 36% who perceived themselves at risk and 35% who did not perceive themselves at risk were, in fact, positive for HPV (p = ns). The majority of women have little knowledge of HPV infections and have attributed many negative emotions associated with infectivity. These negative attributes appear to influence women's decision making concerning HPV testing. The risk of HPV infection in this nonclinic group was substantial, suggesting that even in a nonclinic group, the prevalence of HPV is quite high. Perception of risk was unrelated to actual risk (HPV positive test), reflecting the lack of self-identified risk.

Clinical role of HPV testing

The subjectivity of morphologic methods contributes to a "swamping" of colposcopic services, excessive costs, overdiagnosis, and overtreatment. HPV DNA testing provides the objectivity required to clarify difficult patient management issues, including follow-up, for low-grade cytologic abnormalities (ASCUS and LSIL), noncorrelating (nonconfirmed) Pap smears, evaluation of nondiagnostic lower genital tract lesions, and cytology and histology laboratory quality assurance. Additionally, favorable preliminary data on HPV testing as a primary screen raise the exciting prospect of potentially lowering costs of cervical cancer-screening programs, while further decreasing the incidence of cervical cancer.

Risk factors for HPV DNA detection in middle-aged women

BACKGROUND AND OBJECTIVES

Strong epidemiologic evidence indicates that human papillomavirus (HPV) is the main etiologic factor of cervical cancer. A few cohort studies suggest that most HPV infections are transient in young women and that persistent HPV infections are more common in older women. Little is known about the determinants of persistent HPV infections. The present study was aimed at increasing our knowledge about these determinants.

GOALS

To identify risk factors for genital HPV DNA detection among cytologically normal middle-aged women.

STUDY DESIGN

Eight hundred ten women who participated as control subjects in three case-control studies on cervical cancer in Spain, Colombia, and Brazil were included in this study. After an interview, women underwent a gynecologic examination with collection of exfoliated cells for a Papanicolaou smear and HPV DNA detection. Human papilloma virus DNA was detected by polymerase chain reaction (PCR)-based hybridization techniques.

RESULTS

The HPV positivity rate was 10.5% in the whole population, but was higher in the areas with high incidence of cervical cancer (17% in Brazil and 13% in Colombia) than in Spain (4.9%), which is a low-risk area for cervical cancer. Age was related to the prevalence of HPV DNA in Brazil, but not in Spain and Colombia. In univariate analyses in all three countries, the prevalence of HPV DNA was positively associated with the number of lifetime sexual partners and inversely associated with the levels of family income and with age at first sexual intercourse. There was four times increase in the odds ratio (OR) of HPV infection in women who had six or more lifetime sexual partners compared with those with one or less. The use of any kind of contraceptive tended to decrease the OR for HPV detection. Their ORs ranged from 0.44 (barrier methods) to 0.48 (oral contraceptives). In Spain and Colombia, antibodies against Chlamydia trachomatis were positively associated with the prevalence of HPV DNA. In a final multivariate model, the positive associations with lifetime number of sexual partners, socioeconomic status, and C. trachomatis persisted.

CONCLUSIONS

These results support the sexual transmission of HPV and suggest that socioeconomic status and antibodies to C. trachomatis are independent predictors of HPV detection in middle-aged cytologically normal women.

Papillomavirus infections--a major cause of human cancers

The papillomavirus family represents a remarkably heterogeneous group of viruses. At present, 77 distinct genotypes have been identified in humans and partial sequences have been obtained from more than 30 putative novel genotypes. Geographic differences in base composition of individual genotypes are generally small and suggest a low mutation rate and thus an ancient origin of today's prototypes. The relatively small size of the genome permitted an analysis of individual gene functions and of interactions of viral proteins with host cell components. Proliferating cells contain the viral genome in a latent form, large scale viral DNA replication, as well as translation and functional activity of late viral proteins, and viral particle assembly are restricted to differentiating layers of skin and mucosa. In humans papillomavirus infections cause a variety of benign proliferations: warts, epithelial cysts, intraepithelial neoplasias, anogenital, oro-laryngeal and -pharyngeal papillomas, keratoacanthomas and other types of hyperkeratoses. Their involvement in the etiology of some major human cancers is of particular interest: specific types (HPV 16, 18 and several others) have been identified as causative agents of at least 90% of cancers of the cervix and are also linked to more than 50% of other anogenital cancers. These HPV types are considered as 'high risk' infections. Their E6/E7 oncoproteins stimulate cell proliferation by activating cyclins E and A, and interfere with the functions of the cellular proteins RB and p53. The latter interaction appears to be responsible for their mutagenic and aneuploidizing activity as an underlying principle for the progression of these HPV-containing lesions and the role of high risk HPV types as solitary carcinogens. In non-transformed human keratinocytes transcription and function of viral oncoproteins is controlled by intercellular and intracellular signalling cascades, their interruption emerges as a precondition for immortalization and malignant growth. Recently, novel and known HPV types have also been identified in a high percentage of non-melanoma skin cancers (basal and squamous cell carcinomas). Similar to observations in patients with a rare hereditary condition, epidermodysplasia verruciformis, characterized by an extensive verrucosis and development of skin cancer, basal and squamous cell carcinomas develop preferentially in light-exposed sites. This could suggest an interaction between a physical carcinogen (UV-part of the sunlight) and a 'low risk' (non-mutagenic) papillomavirus infection. Reports on the presence of HPV infections in cancers of the oral cavity, the larynx, and the esophagus further emphasize the importance of this virus group as proven and suspected human carcinogens.

Sexual risk behavior in women with cervical human papillomavirus infection

In a study of 972 women, sexual characteristics of 66 women with a cervical human papillomavirus infection (CHPI) were compared to the remaining study population. Among a number of sexual variables that were significantly correlated with CHPI were number of lifetime sexual partners, short partnerships, many recent partners, infidelity, casual travel sex, sexual début abroad, oral and anal sex, and sexual abuse. In multifactorial analyses four variables remained significantly correlated with CHPI, i.e., number of lifetime sexual partners, casual travel sex, sexual début abroad, and infidelity. It is concluded that CHPI shows most of the epidemiological characteristics of a sexually transmitted disease.

Human papillomavirus expression in oral mucosa, premalignant conditions, and squamous cell carcinoma: a retrospective review of the literature

OBJECTIVES

The literature of human papillomavirus detection in normal oral mucosa and oral lesions associated with the dysplastic progression of epithelium was reviewed to help define the role of this virus in the development of oral squamous cell carcinoma.

STUDY DESIGN

All available data from published studies were analyzed by chi-square test for association between the human papillomavirus and age, gender, race, DNA type, location, lesional dysplastic progression, method of detection, tissue preservation, and use of tobacco and alcohol.

RESULTS

Human papillomavirus was identified with increasing frequency in normal oral mucosa (13.5%), benign leukoplakia (14.8%), intraepithelial neoplasia (18.5%), squamous carcinoma (26.2%), and verrucous carcinoma (27%). It was detected in oral squamous cell carcinoma significantly (p < 0.005) more often (37.1%; 122 of 329) in studies that used a high sensitivity assay (polymerase chain reaction) than studies that used moderate sensitivity assays (25.2%; 84 of 334) (e.g., Southern blot hybridization) and low sensitivity assays (16.9%; 61 of 362) (e.g., immunohistochemistry, in situ hybridization). Human papillomavirus DNA was detected significantly more often (p < 0.001) in frozen oral squamous cell carcinoma (51.6%; 115 of 223) than paraffin-embedded tissue (21.7%; 136 of 628). High-risk human papillomaviruses (2, 16, 18) were detected in 81.4% of OSCCs that contained the virus compared with low-risk human papillomavirus genotypes (6, 11) in 17.9% of oral squamous cell carcinoma that contained the human papillomavirus (p < 0.001). In studies that analyzed the use of chemical cofactors, the use of tobacco and alcohol (87.3%) was associated more often with oral squamous cell carcinoma than the presence of human papillomavirus (51.3%), however, the difference was not significant.

CONCLUSION

High-risk human papillomavirus genotypes have a significant association with oral squamous cell carcinoma. However, the presence of this virus in a high proportion of oral normal mucosa makes the virus alone a poor prognosticator of progression to malignancy.

Declining prevalence of cervicovaginal human papillomavirus infection with age is independent of other risk factors

BACKGROUND AND OBJECTIVES

Human papillomavirus (HPV) infection of the female genital tract is the most common sexually transmitted disease. Although the prevalence of HPV in women without detectable cervical disease has been shown to decline with increasing age, the relationship to sexual behavior has not been investigated.

GOAL

To identify risk factors for, and associated with the age-dependent decline in, genital HPV infection in women.

STUDY DESIGN

The prevalence of HPV was determined in a cohort of 439 sexually active inner-city women between the ages of 18 and 50 years recruited in Brooklyn, New York. Cervicovaginal cells were collected by lavage, and HPV was detected by low-stringent Southern blot hybridization.

RESULTS

The prevalence of HPV infection ranged from 36% in women younger than 25 years of age to 2.8% in women 45 years or older. Logistic regression analysis identified an increased risk for cervical HPV infection to be independently associated with number of sex partners in the past year (odds ratio [OR], 1.04 per yearly increase in age; 95% confidence interval [CI], 1.00 to 1.08), younger age (OR, 0.92 per year increase in age; 95% CI, 0.88 to 0.95), and not living with partner (OR, 2.28; 95% CI, 1.40 to 4.22).

CONCLUSIONS

The lower prevalence of HPV infection in older women compared to younger women was found to be independent of sexual behavior. These results suggest that a biologic effect, such as HPV immunity acquired over time and with multiple exposures, may mediate the inverse relationship between age and HPV prevalence.

Comparison of development of serum antibodies to HPV16 and HPV33 and acquisition of cervical HPV DNA among sexually experienced and virginal young girls. A longitudinal cohort study

OBJECTIVES

To study the importance of sexual activity and early coitus debut on the risk for acquiring infection with human papillomavirus (HPV) type 16 or 33.

STUDY DESIGN

Ninety-eight healthy adolescent girls were followed up with consecutive interviews and donations of serum and cervical brush samples during 2 years.

RESULTS

Fourteen percent of sexually experienced girls had serum immunoglobulin G to HPV16 and/or HPV33 capsids, and 14% also had cervical HPV16 or HPV33 DNA. Seropositivity for HPV correlated with detection of cervical HPV DNA. None of the 36 girls without coital experience was seropositive or harbored cervical HPV DNA. Seropositivity for HPV was correlated strongly with the number of sexual partners: Odds ratio for > 1 sexual partner was 16.3 (P < 0.001), and for early coitus debut (younger than 17 years of age), it was 14.3 (P < 0.002).

CONCLUSIONS

Both HPV serology and HPV DNA testing indicated that the number of sexual partners and earliness of coitus debut determined the risk for acquiring HPV infection and that nonsexually transmitted infections are rare or nonexistent among adolescent girls.

Contraceptive use and reproductive history in women with cervical human papillomavirus infection

The study was conducted to investigate whether cervical human papillomavirus infections (CHPI) are associated with contraceptive use and reproductive history. The contraceptive and reproductive histories in 972 women seeking contraceptive advice were noted and screening conducted for human papillomavirus infection. The interview included number of pregnancies and childbirths, legal and spontaneous abortions, and menstrual pattern. Information about current use of contraceptive methods, about casual sex, and history of combined oral contraceptive pill (OC) use was obtained. Women with a history of spontaneous abortion showed a significant correlation with CHPI, as did women who used high-dose OCs when compared with the remaining study population (odds ratio 3.0). There was no association between use of low-dose OCs and CHPI. In multifactorial analyses with adjustment for age, number of lifetime sexual partners, number of partners during the preceding six months and age at first intercourse, the significant correlation between use of high-dose OCs and CHPI remained (adjusted odds ratio 2.8). The results indicate a relationship between female steroid hormones and the occurrence of CHPI. An association with high-dose OCs could not be excluded.

The epidemiology of cervical carcinogenesis

Epidemiologic and laboratory data suggest that cervical cancer typically arises from a series of causal steps. Each step can be studied separately in the hope of better etiologic understanding and improved cancer prevention. The earliest identified etiologic step is infection of young women with specific types of venereally transmissible human papillomaviruses (HPVs). Cervical HPV infections often lead to low grade squamous intraepithelial lesions (mildly abnormal Pap smears). Human papillomavirus infections and their associated lesions are extremely common among young, sexually active women. The infections typically resolve spontaneously even at the molecular level within months to a few years. Uncommonly, HPV infections and/or low grade lesions persist and progress to high grade lesions. The risk factors for progression are mainly unknown but include HPV type and intensity, cell-mediated immunity, and reproductive factors. Nutritional factors or co-infection with other pathogens may also be involved at this apparently critical etiologic step between common low grade and uncommon high grade intraepithelial lesions. Except for advancing age, no epidemiologic risk factors have been found for the next step between high grade intraepithelial lesions and invasive cancer. At the molecular level, invasion is associated with integration of viral DNA. Based on worldwide research, the steps in cervical carcinogenesis appear to be fundamentally the same everywhere, with a central role for HPV infection. The importance of etiologic cofactors like smoking, however, may vary by region.

Smoking, alcohol, sexual behaviour and drug use in women with cervical human papillomavirus infection

OBJECTIVE

The aim of the study was to determine if smoking is associated with cervical human papillomavirus infection (CHPI) independent of sexual risk factors.

SETTING

Two family planning clinics and one youth clinic in Sweden.

SUBJECTS

Human papillomavirus (HPV) DNA was found in cervical samples of 66 (6.8%) of 972 women attending for contraceptive advice, using Southern blot tests.

RESULTS

Among women with cervical human papillomavirus infection (CHPI), 33 (50%) were smokers, as compared to 307 (33.9%) among a comparison group of HPV-negative women (odds ratio = 2.0, 95% CI = 1.2-3.2). After stepwise adjustment for number of lifetime partners, number of partners last six months, age at first intercourse, alcohol use, drug abuse and history of or current sexually transmitted disease other than CHPI, the odds ratio decreased to 1.4 (95% CI = 0.8-2.4). Recent use of alcohol and ever use of narcotics were also significantly correlated to CHPI in crude analyses, but vanished in multifactorial analyses after adjustment for the mentioned sexual risk behavioral factors.

CONCLUSIONS

The results of this study indicate that smoking, alcohol and drug abuse are risk markers, but not causal factors, for CHPI.

Sexually-transmitted disease in female adolescents: effects of psychosocial factors and high risk behaviors

BACKGROUND

Although previous studies have reported behavioral correlates of sexually-transmitted diseases (STDs) and psychosocial correlates of risky behavior, research has not examined the linkages between psychosocial attributes, behavioral patterns, and actual STD acquisition within the same adolescent sample. We examined the effects of five psychosocial factors on risky sexual behavior and substance use, and their direct and indirect effects on STD acquisition.

METHODS

A multiethnic sample of 571 sexually-active female adolescents (ages 13-19 years) was recruited from family planning clinics. Subjects completed questionnaires prior to their gynecologic examination and STD testing.

RESULTS

A multiethnic sample of 571 sexually-active female adolescents (ages 13-19 years) was recruited from family planning clinics. Subjects completed questionnaires prior to their gynecologic examination and STD testing.

RESULTS

Female adolescents who were heavy substance users, who felt little control over their sexual behavior, and had a greater number of friends who engaged in risky sexual behavior were themselves more likely to engage in risky sexual behavior. Risky sexual behavior was associated with positive STD status. Subjects who used psychoactive substances during sex reported higher numbers of sexual partners and were more likely to have an STD.

CONCLUSIONS

This research has identified possible causal paths by which psychosocial factors may influence specific behaviors that are predictive of STDs in adolescent females.

Infection by the human papillomavirus in teenagers sexually active: clinic and subclinic manifestations

This research studies the association of the cervical condyloma with the intraepithelial neoplasia, during sex activity, pregnancy, diagnose methods, cytology and colposcopy in teenagers. The objective of this research is to study the propaedeutics for the uterine coli condyloma diagnose in a group of teenagers. For this purpose, we have studied 131 teenagers sexually active with ages between 14 and 19 years and presenting histologically confirmed uterine coli condyloma. Association with intraepithelial neoplasia, sexual activity duration, method of diagnose, pregnancy analysis, cytology and colposcopy results and association with vulva and vagina injuries were evaluated. The high association rate with condyloma and intraepithelial neoplasia after a short time of sexual activity and the none presence of macroscopic warts in the genital organs in 80% of cases presenting cervical condyloma, demonstrate that: a more careful investigation with colposcopy and biopsy of the inferior genitals of the women-teenagers sexually active is needed, when presenting modified cervical cytology.

Epidemiology of cervical intraepithelial neoplasia: the role of human papillomavirus

The evidence implicating specific HPV types in the aetiology of cervical cancer is now strong enough to establish a causative role. HPV infection of the cervix affects the developing immature metaplastic cells of the transformation zone. Cervical neoplasia can be viewed as the interaction of high risk papillomavirus and immature metaplastic epithelium. Once maturity is reached, there is minimal risk of subsequent development of cervical squamous neoplasia. Exposure to HPV is an extremely common event, especially in young sexually active women. Yet, despite frequent HPV exposure at that phase of life in which the cervical transformation zone is at its most vulnerable, established expressed disease is relatively uncommon. Most studies in which the natural history of CIN is not altered by cervical biopsy reveal a progression rate from low to high grade CIN of less than one third. Where viral type is taken into account, however, the progression rate from normal but high risk HPV-infected cervical epithelium to CIN 2 or 3 is higher. Despite this, most cervical abnormalities will not transform into invasive cancer, even if left untreated. The variance between the high rate of HPV infection, the intermediate rate of CIN and the relatively low rate of cervical cancer establishes a stepwise gradient of disease of increasing severity with decreasing prevalence. In an immunocompetent host, HPV infection alone does not appear to be sufficient to induce the step from high grade CIN to invasion. Epidemiological studies indicating that HPV infection with oncogenic viral types is far more common than cervical neoplasia suggest the necessity of cofactors in cervical carcinogenesis. The long time-lag between initial infection and eventual malignant conversion suggests that random events may be necessary for such conversion, and the spontaneous regression of many primary lesions suggests that most patients are not exposed to these random events. Potential cofactors include cigarette smoking, hormonal effects of oral contraceptives and pregnancy, dietary deficiencies, immunosuppression and chronic inflammation. In those women who develop cervical cancer, malignant progression is rarely rapid, more commonly taking many years or decades. Malignant progression has been documented in patients who presented initially with only low grade HPV-induced atypia. On the other hand, progression may be a misnomer, as 'apparent' progression may really represent adjacent 'de novo' development of higher grade CIN. Although most cervical cancers contain high risk HPV types, up to 15% of such cancers test negative for HPV, raising the possibility that a few, usually more aggressive, cervical cancers may arise from from a non-viral source.(ABSTRACT TRUNCATED AT 400 WORDS)

Impact of sexual habits on the clinical evaluation of male HPV infection

A series of 199 male regular sexual partners of women attending an STD clinic for the examination and treatment of HPV-associated diseases was examined by peniscopy, surgical biopsy and nucleic acid hybridization for the presence of clinical, histological and molecular markers pathognomic of HPV infection. There was a 100% correlation between condylomata acuminata and detection of HPV type 6 or 11 DNA. Papillary lesions displayed neither histological signs of HPV infection, nor did they harbor HPV DNA (viral types 6, 11, 16, 18, 33) while 44.9% (22/49) of acetowhite epithelia showed HPV-suggestive histological changes. Of the 19 analysed for HPV DNA, 15.8% (3/19) harbored HPV 6/11 and 16 DNA. Regular male and female sexual partners did not always harbor the same HPV types, showing that latent or occult infection and the sexual habits of each individual play an important role in the clinical manifestations of HPV infection observed in sexual couples. The present data show that: i) the likelihood of developing a clinical HPV lesion was affected, to a large extent, by the previous sexual history and habits in the partners of women with flat condylomata, while partners of women with condylomata acuminata or CINs displayed a higher correlation with the current state of infection in their regular partner; ii) despite the assessed infective state of their consorts, men with a low lifetime number of sexual partners seldom displayed HPV-associated acetowhitening.(ABSTRACT TRUNCATED AT 250 WORDS)

Prevalence of HPV 16 and 18 DNA sequences in CIN III lesions of adults and adolescents

Adolescents may be more susceptible to cervical human papillomavirus (HPV) infections and may have more rapid progression of cervical intraepithelial neoplastic (CIN) lesions than adults. We evaluated Papanicolaou (Pap) smears and cervical tissue specimens from a consecutive series of 25 adolescent (age 15-20 yr) and 17 adult (age 35-40 yr) patients with a histologic diagnosis of CIN III. The study patients were all Detroit residents enrolled in a health maintenance organization (HMO) affiliated with Henry Ford Hospital. The cervical tissue specimens were evaluated for HPV 6b/11, HPV 16, and HPV 18 using agarose gel electrophoresis and Southern hybridization following polymerase chain reaction (PCR) DNA amplification. While the small sample size precluded testing for statistical significance, HPV 16 and/or HPV 18 DNA was detected in specimens from 21/25 (84%) adolescents compared to 12/17 (71%) adults (odds ratio [OR] = 2.2; 95% confidence interval [CI] = 0.49-9.74). The relationship between adolescence and HPV infections appears to be stronger for HPV 18 and mixed HPV 16/18 infections (OR = 5.6; 95% CI = 0.7-42.4) than for HPV 16 infections (OR = 1.93; 95% CI = 0.4-8.8). None of the cervical specimens contained HPV 6b/11 DNA. Oral contraceptive (OC) use was associated with HPV infection in patients with CIN III, but there was no association between cigarette smoking and HPV infection. The effect of OC use on the relationship of age and HPV could not be evaluated due to small sample size. The effects of previous sexually transmitted disease (STD) on the relationship of age and HPV were assessed.(ABSTRACT TRUNCATED AT 250 WORDS)

Female adolescents at high, moderate, and low risk of exposure to HIV: differences in knowledge, beliefs, and behavior

PURPOSE

To examine differences in the beliefs and behaviors of female adolescents at varying degrees of probable risk for HIV transmission.

METHODS

A clinically-based, ethnically diverse sample of 696 sexually active female adolescents was recruited from urban and suburban general adolescent, family planning, and public health clinics. Subjects were categorized into four risk status groups on the basis of their history of IV drug use, sexually transmitted disease (STD), and probable risk of contact with an infected individual (living in a high-risk geographic location, sexual promiscuity, sex with male homo/bisexuals).

RESULTS

Females in the highest risk group showed high rates of substance use, anal intercourse, and intentions to have future risky sexual partners. A second high-risk group reported high rates of STDs, inconsistent condom use, and less AIDS knowledge.

CONCLUSION

Different subsets of higher risk adolescents may require different intervention strategies.

Low-grade squamous intraepithelial lesions: cytologic predictors of biopsy confirmation

One hundred and seven smears demonstrating a low-grade squamous intraepithelial lesion (LSIL) were analyzed for features predicting subsequent biopsy confirmation. Twelve (29%) of 41 smears showing few LSIL cells were biopsy confirmed compared to 33 (60%) of 55 containing an intermediate number of LSIL cells and 9 (82%) of 11 displaying many LSIL cells (P < 0.002). Thirty-seven (47%) of 78 smears showing mainly condylomatous atypia (CA), 7 (54%) of 13 revealing predominantly cervical intraepithelial neoplasia 1 (CIN 1), and 10 (63%) of 16 displaying both CA and CIN 1 were histologically confirmed (N.S.). Biopsy confirmation was obtained in 35 (65%) of 54 women whose repeat smears obtained at colposcopy demonstrated SIL compared to four (15%) of 26 patients whose repeat smears were normal or contained atypical squamous cells of undetermined significance (P < 0.001). These results suggest that the number of diagnostic cells in an LSIL smear predicts biopsy confirmation and affirm the validity of combining CA and CIN 1 under the category of LSIL in the Bethesda System.

Cervico-vaginal Chlamydia trachomatis infection in pregnant adolescent and adult women. A morphologic and immunofluorescent study

We studied the incidence of cervical Chlamydia trachomatis (CT) in 65 adolescents aged between 14 and 19 years and 65 adults aged 20 years or more. All subject were more than three months advanced in a normal pregnancy. Two samples for cytology were obtained from each patient, one ecto- and endocervical, with Ayre's spatula and cytobrush, and one only endocervical with cytobrush. The first one was examined after Papanicolaou staining and the second one was examined with the easily performed immunofluorescence reaction to CT (IF)--Microtrak, SYVA. Twenty seven adolescent patients (41.5%) and fourteen adults (21.5%) had a positive IF test for CT; the rate in adolescents was significantly higher (P < 0.01) than in adults. The Papanicolaou (Pap) stained slides, examined blind for evidence of CT infection showed a sensitivity of 70.7%, a specificity of 95.5% and positive and negative predictive values of 87.8% and 87.6% respectively. Seven adolescents showed cytological signs of Papillomavirus (HPV) infection, and six of them were also CT positive; five had signs of HPV infection and 4 of them were CT positive.

Pap smear screening for adolescents: rationale, technique, and follow-up

Cervical cytologic abnormalities are increasingly prevalent in teenagers. Adolescents are at greater risk for cervical neoplasia than adult women because of the biologic changes occurring in the cervix during puberty, the prevalence of human papillomavirus, and the behavioral risk factors in this age group. Two behavioral risk factors are early age at first coitus and multiple sex partners. Human papillomavirus is widely believed to be the etiologic agent associated with the spectrum of cervical neoplasias. Papanicolaou smear technique, reporting, and management of abnormal smears in teens is explained.

Pathogenesis of genital HPV infection

Clinical, subclinical, and latent human papillomavirus (HPV) infections are distinguished from HPV-associated neoplasia. Besides HPV additional cofactors are necessary to transform HPV infected tissue to intraepithelial or invasive neoplasia. Risk factors for the presence of HPV are high number of sexual partners, early cohabitarche, young age at first delivery, suppression and alteration of immune status, young age and hormonal influences. While the fact of a high number of sexual partners exclusively increases the risk of HPV infection, it is not known whether the other factors lead to either an increased risk for HPV infection and/or to HPV-associated neoplasia. Subclinical and latent genital HPV infections are highly prevalent. The prevalence rate depends on the sensitivity of the HPV detection system used, on age and sexual activity of the population screened, and on the number of subsequent examinations performed for each subject. Sexual transmission is the main pathway for genital HPV's, however, vertical, peripartal, and oral transmission are also possible. Seroreactivity against genital HPV may be due to an active infection or the result of contact with HPV earlier in life. Antibodies against the HPV 16 E7 protein indicate an increased risk for cervical cancer. Compared with humoral response cellular immune response is probably more important for regression of genital HPV infection: impaired cellular response is characterized by depletion of T helper/inducer cells and/or Langerhans cells and impaired function of natural killer cells and/or the infected keratinocyte. In condylomata replication and transcription of viral nucleic acids and antigen production coincide with cellular differentiation. However, the interaction between HPV and the keratinocyte on a molecular level in subclinical and latent disease is not well understood. Regression or persistence of subclinical and latent genital HPV infections as observed in longitudinal investigations show a constant come-and-go of HPV presence. Subclinical or latent cervical infections with high-risk HPV types (such as HPV 16 and 18) have an increased risk for the development of HPV-associated neoplasia.

Prevalence of HPV in a Melbourne female STD population: comparison of RNA and DNA probes in detecting HPV by dot blot hybridization

A total of 377 women, consecutively selected as first attenders to a sexually transmitted diseases clinic in Melbourne, Australia, were examined for overt Condylomata acuminata and were screened for genital HPV DNA types 6, 11, 16, 18, 31, 33 and (35) using 2 dot blot hybridization methods. Overall, there was a 90% positivity correlation between the 2 methods with HPV DNA being detected in 12% of ectocervical samples. Overt warts were found in 15% of the women and HPV DNA was detected at the cervix in 35% with cytology predicting HPV with or without dysplasia in 27%. Thirteen percent had a past history of warts but none on examination and HPV DNA was evident in 16% while 18% had cytological features of HPV. Those with no warts evident and no past history of warts had both HPV DNA and cytological features of HPV in 7%.

Papillomavirus infection and its pathologic correlate in sexually active adolescents

We investigated the prevalence of human papillomavirus (HPV) and its pathologic correlation in an adolescent clinic population (13-20 years, mean 16 years) over a 2-year period. 413 cervical specimens were obtained and analyzed cytologically and by a Southern Blot (SB) method for HPV DNA. 277 specimens from 210 patients could be fully analyzed. 23 patients (10.9%) were positive for HPV DNA by SB. Cytologic findings in these 23 patients demonstrated changes compatible with low-grade squamous intraepithelial lesions (LGSIL) and HPV-associated changes in 4 cases (17%). Cervical biopsies obtained in 3 cases with abnormal cytology demonstrated LGSIL in all cases. 6 patients were retested for HPV 2 to 6 months after the initial positive, two showed persistence of the initial virus, one was positive for a different HPV type and three were negative for HPV DNA.

Comparison between colposcopic, cytologic, and histologic findings in women positive and negative for human papillomavirus DNA

Little is known about the role of detection of human papillomavirus (HPV) DNA in exfoliated cells of the cervix in aiding the colposcopic diagnosis of cervical lesions. The purpose of our study was to compare the colposcopic findings of young women who were positive and negative for HPV DNA. Eighty-four women aged 13-22 years attending family planning clinics were examined colposcopically with the aide of acetic acid and Lugol's solution and without knowledge of HPV DNA status. Lesions identified were given scores based on the severity of observed colposcopic changes. Samples for cytology and HPV DNA testing, which included types 6, 11, 16, 18, 31, 33, and 35, were obtained at the time of the examination. Biopsies were performed on women with significant lesions identified on examination or with cytology suggestive of neoplasia. Students t-test and chi 2 analysis were performed to compare colposcopic variables and HPV DNA type. Of the 84 women examined, 17 were positive for HPV DNA; 9 had type 16/18. The average length of sexual activity was 2.7 years. Women with HPV 16/18 had a mean of 1.7 lesions visible at colposcopy compared to 0.7 lesions visible in those negative for HPV 16/18 (this included HPV DNA negative women and women positive for HPV types 6, 11, 31, 33, and 35) (p < 0.001). Women who were positive for HPV 16/18 also had higher lesional scores than the HPV 16/18-negative group (3.4 versus 1.0, respectively, p < 0.001). All four women who had dysplasia either on cytology or histology were positive for type 16/18.(ABSTRACT TRUNCATED AT 250 WORDS)

Demographic predictors of mammography and Pap smear screening in US women

OBJECTIVES

Proven screening technologies exist for both breast and cervical cancer, but they are underused by many women. We sought to evaluate the effect of demographic characteristics on the underuse of mammography and Pap smear screening.

METHODS

We analyzed responses from 12,252 women who participated in the 1987 National Health Interview Survey Cancer Control Supplement. Demographic profiles were produced to target severely underserved groups of women.

RESULTS

Low income was a strong predictor of mammography underuse, as was Hispanic ethnicity and other race, low educational attainment, age greater than 65, and residence in a rural area. A strong predictor of never having had a Pap smear was never having been married; however, the importance of this characteristic is difficult to interpret in the absence of data on sexual activity. Hispanic women and women of other races of all ages and all income levels underused Pap smear screening, as did older women, particularly older Black women.

CONCLUSIONS

The tendency of women to underuse screening technologies varies greatly across levels of basic demographic characteristics. The importance of these characteristics differs for mammography screening versus Pap smear screening.

Abnormal cervical cytology in adolescents: a literature review

This article reviews the literature on the subject of cervical cytological abnormalities in teenagers, defined as a Papanicolaou (Pap) smear result more severe than inflammation. There is discussion of the increasing prevalence of this problem in adolescents. Behavioral and biologic risk factors are examined. The role of the human papillomavirus, widely believed to be the etiologic agent, is addressed. Atypia, its relationship to cervical malignancies, and its management are reviewed. The possible role of the human immunodeficiency virus in the increasing prevalence of cytological abnormalities in teens is considered.

PCR-detected genital papillomavirus infection: prevalence and association with risk factors for cervical cancer

In an investigation conducted in student health clinic patients, the polymerase chain reaction was used to detect human papillomavirus (HPV) DNA, thereby allowing measurement of the prevalence of HPV infection and study of the association between HPV infection and risk factors for cervical cancer. Of 159 women eligible to participate, 105 (66%) provided a specimen of cervical cells for HPV typing, and also answered an interviewer-administered questionnaire which sought information on risk factors for cervical cancer. Nucleic acid extracted from cervical cells was screened with primers for HPV types 6, 11, 16, 18, 33 and with an HPV Consensus primer. Overall, the prevalence of HPV infection was 18.1%, while for HPV-6/11 it was 2.9% and for HPV-16/18 it was 10.5%. There were statistically significant increases in risk of HPV infection with a history of ever having smoked cigarettes (overall, and for HPV-16 alone) and with a history of usually having sexual intercourse during menstrual periods (overall, but not for HPV-16), and these associations were independent of the effects of age at first sexual intercourse and number of sexual partners. The latter 2 variables, as well as the total number of occasions of sexual intercourse, a history of anal intercourse, and a history of ever having used oral contraceptives, were not associated with statistically significant alterations in risk of HPV infection.

Cervicovaginal human papillomavirus infection in suburban adolescents and young adults

To investigate the prevalence rates of and risk factors for genital human papillomavirus (HPV) infection in white, middle-class adolescents, we obtained specimens for HPV from 107 patients undergoing pelvic examination at a suburban adolescent health service. Specimens were obtained by means of cervicovaginal lavage and were analyzed for HPV DNA by Southern blot analysis. The subjects' mean age was 18.5 (+/- 2.0 SD) years; 47% of the subjects were seen for contraception, 36% for possible pregnancy, 12% for a gynecologic complaint, and 5% for a general examination. We detected HPV in 32% of patients; HPV types included 6/11 (6%), 16 (3%), 18 (15%), 31 (3%), 42 (6%), 45 (18%), and 56 (6%). The DNA type was classified as uncharacterized in 47%, and 3% had more than one type. Univariate analysis revealed that patients found to have HPV were more likely to have more than two sexual partners, to have been sexually active for more than 2 years, to have had menarche before 12 years of age, and to have a history of sexually transmitted disease; logistic regression multivariate analysis demonstrated that number of partners and age at menarche were independent risk factors for HPV. These data indicate that HPV is common among sexually active teenagers regardless of ethnicity or socioeconomic status. The association of cervicovaginal HPV infection with sexual activity further supports the notion of the sexual transmission of this agent.

The association between human papillomavirus deoxyribonucleic acid status and the results of cytologic rescreening tests in young, sexually active women

We examined the utility of cytologic rescreening tests in women who had positive test results for human papillomavirus deoxyribonucleic acid but who were diagnosed as having benign conditions at cytologic testing. One hundred twenty-five Papanicolaou smears from women who were screened for human papillomavirus deoxyribonucleic acid were sent routinely to a private laboratory for diagnoses. These slides were then reviewed independently by two pathologists who were blinded to the human papillomavirus deoxyribonucleic acid results. The effects of cytologic rescreening in cases of both positive and negative human papillomavirus deoxyribonucleic acid were assessed by calculating z scores. Cervical intraepithelial neoplasia was diagnosed in 40% by pathologist A and in 20% by pathologist B of the human papillomavirus-positive subjects compared with none diagnosed by the private cytology laboratory (z = 3.09, p less than 0.005 and z = 1.98, p less than 0.05, respectively). No significant differences were found in the human papillomavirus-negative group. We conclude that cytologic rescreening in human papillomavirus deoxyribonucleic acid-positive women who were initially diagnosed as having benign cytologic results will yield a significant proportion of cases of cervical intraepithelial neoplasia.