Human papillomavirus and long-term oral contraceptive use increase the risk of adenocarcinoma in situ of the cervix.

We examined United States Surveillance, Epidemiology, and End Results incidence data and conducted a population-based case-control study to examine the role of human papillomavirus (HPV) and oral contraceptive (OC) use in the etiology of adenocarcinoma in situ of the cervix (ACIS). One hundred and fifty women diagnosed with ACIS and 651 randomly selected control women completed in-person interviews. The presence of HPV DNA in archival ACIS specimens was determined by E6 and L1 consensus PCR. Serum samples from case and control subjects were collected at interview, and antibodies to HPV-16 L1 and HPV-18 L1 were detected by virus-like particle capture assays. The overall prevalence of HPV DNA was 86.6%, with 39.0% positive for HPV-16 DNA, 52.4% positive for HPV-18 DNA, and 13.4% positive for more than one HPV type. The age-adjusted relative risk of ACIS associated with HPV-18 seropositivity was 3.3 (95% confidence interval 2.2-4.9). No increased risk was associated with antibodies to HPV-16 L1. Among women born after 1945, the relative risk increased with duration of OC use, with the highest risk for 12 or more years of use (odds ratio, 5.5; 95% confidence interval, 2.1-14.6) relative to nonusers. The detection of HPV DNA in 86.6% of ACIS and the strong association of ACIS with HPV-18 L1 seropositivity underscore the importance of HPV, particularly HPV-18, in the etiology of ACIS. In addition, long-term OC use may contribute to the pathogenesis of these tumors in some women.

Human papillomavirus 16 and 18 L1 serology compared across anogenital cancer sites.

Human papillomavirus (HPV) DNA has been detected in the great majority of cancers of the uterine cervix and anus, whereas the association of HPV DNA with cancer at other anogenital sites has produced less consistent results. This study was designed to compare HPV exposure among anogenital cancer cases and matched controls. Cases (1782) of anogenital cancer diagnosed in the Seattle area from 1978 to 1998 were identified and interviewed. Their responses were compared with those of 2383 age- and sex-matched controls. Blood was drawn at interview from both cases and controls and tested for antibodies to HPV-16 and HPV-18. Tissue blocks were tested for HPV DNA for 649 cases. Serum antibodies to HPV-16 were associated with in situ and invasive cancer at all sites among men and women with the exception of in situ penile cancer. Anti-HPV-18 antibodies were associated with cancers at all sites among women. The increased risk of cancer associated with HPV-16 seropositivity ranged from odds ratio = 1.8 (95% confidence interval, 1.4-2.5) for adenocarcinoma of the cervix to odds ratio = 5.9 (95% confidence interval, 3.4-10.3) for anal cancer in men. Associations between seroprevalence and cancers were stronger when analyses were restricted to HPV-16- or HPV-18 DNA-positive cases. HPV DNA was detected in >80% of cancers from all sites tested. HPV-16 DNA was the type most frequently detected at all sites (range, 40.9-82.2%). HPV-18 DNA was detected in 44.7% of adenocarcinomas of the cervix but detected much less often (2.6-18.1%) at other sites. These findings support an important role for HPV infection in anogenital cancer at all sites. Differences in the proportion of seropositives among HPV-16 DNA-positive cases by site suggest either that the immune response varies by site or that cancer development may lead to changes in antibody responses in a site-specific fashion.

The p53 Arg72Pro polymorphism, human papillomavirus, and invasive squamous cell cervical cancer.

A. Storey et al. [Nature (Lond.), 393: 229-234, 1998)] reported a 7-fold increased risk of cervical cancer associated with having an Arg/Arg polymorphism at codon 72 of p53 compared with the Pro/Arg heterozygotes (odds ratio, 7.4; 95% confidence interval, 2.1-29.4). Complementary in vitro studies suggested that the HPV E6 oncoprotein more readily targets the arginine form, as opposed to the proline form, of p53 for degradation. We investigated the impact of this polymorphism in a population-based case-control study of invasive cervical cancer. Using a PCR assay to detect the p53 codon 72 polymorphism, we tested blood samples from 111 women with invasive squamous cell cancer of the cervix identified by a population-based registry and 164 random-digit telephone-dialed controls. The distribution of the genotype among control women was 38% heterozygous, 7% proline homozygous, and 55% arginine homozygous, and among the cases was 38%, 6%, and 56%, respectively. There was no increased risk of squamous cell invasive cervical cancer associated with homozygosity for the arginine allele (odds ratio, 1.0; 95% confidence interval, 0.6-1.7). Furthermore, there was no modification of this result by human papillomavirus (HPV) DNA status of the tumor, age, or smoking status. Among controls, there was no association between the polymorphism and HPV-16 L1 seropositivity. However, among case subjects, the codon 72 polymorphism may be related to HPV 16L1 seropositivity status.

Oral cancer risk in relation to sexual history and evidence of human papillomavirus infection.

BACKGROUND: Experimental models and analyses of human tumors suggest that oncogenic, sexually transmittable human papillomaviruses (HPVs) are etiologic factors in the development of oral squamous cell carcinoma (SCC). We conducted a population-based, case-control study to determine whether the risk of this cancer is related to HPV infection and sexual history factors. METHODS: Case subjects (n = 284) were 18-65-year-old residents of three counties in western Washington State who were newly diagnosed with oral SCC from 1990 through 1995. Control subjects (n = 477) similar in age and sex were selected from the general population. Serum samples were tested for HPV type 16 capsid antibodies. Exfoliated oral tissue collected from case and control subjects and tumor tissue from case subjects were tested for HPV DNA. Odds ratios (ORs) were calculated after adjusting for age, sex, cigarette smoking, and alcohol consumption. RESULTS: Among males only, oral SCC risk increased with self-reported decreasing age at first intercourse, increasing number of sex partners, and a history of genital warts. Approximately 26% of the tumors in case subjects contained HPV DNA; 16.5% of the tumors contained HPV type 16 DNA. The prevalence of oncogenic HPV types in exfoliated oral tissue was similar in case and control subjects. The ORs for HPV type 16 capsid seropositivity were 2.3 (95% confidence interval [CI] = 1.6-3.3) for all oral SCCs and 6.8 (95% CI = 3.0-15.2) for oral SCCs containing HPV type 16 DNA. The joint association of cigarette smoking and HPV type 16 capsid seropositivity with oral SCC (OR = 8.5; 95% CI = 5.1-14.4) was stronger than predicted from the sum of individual associations with current smoking (OR = 3.2; 95% CI = 2.0-5.2) and seropositivity (OR = 1.7; 95% CI = 1.1-2.6). CONCLUSIONS: HPV type 16 infection may contribute to the development of a small proportion of oral SCCs in this population, most likely in combination with cigarette smoking.

Cofactors with human papillomavirus in a population-based study of vulvar cancer.

BACKGROUND: Human papillomavirus (HPV) has been previously associated with vulvar cancer. In a population-based study, we examined whether exposure to HPV, cigarette smoking, or herpes simplex virus 2 (HSV2) increases the risk of this cancer. METHODS: Incident cases of in situ (n = 400) and invasive (n = 110) squamous cell vulvar cancer diagnosed among women living in the Seattle area from 1980 through 1994 were identified. Serum samples were analyzed for antibodies against specific HPV types and HSV2. HPV DNA in tumor tissue was detected by means of the polymerase chain reaction. In most analyses, case subjects were compared with population-based control subjects (n = 1403). Relative risks of developing vulvar cancer were estimated by use of adjusted odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Increased risks of in situ or invasive vulvar cancer were associated with HPV16 seropositivity (ORs = 3.6 [95% CI = 2.6-4.8] and 2.8 [95% CI = 1.7-4.7], respectively), current cigarette smoking (ORs = 6.4 [95% CI = 4.4-9.3] and 3.0 [95% CI = 1.7-5.3], respectively), and HSV2 seropositivity (ORs = 1.9 [95% CI = 1.4-2.6] and 1.5 [95% CI = 0.9-2.6], respectively). When the analysis was restricted to HPV16 DNA-positive tumors (in situ or invasive), the OR associated with HPV16 seropositivity was 4.5 (95% CI = 3.0-6.8). The OR for vulvar cancer was 18.8 (95% CI = 11.9-29.8) among current smokers who were HPV16 seropositive in comparison with never smokers who were HPV16 seronegative. CONCLUSIONS: Current smoking, infection with HPV16, and infection with HSV2 are risk factors for vulvar cancer. Risk appears particularly strong among women who are both current smokers and HPV16 seropositive.

The natural history of human papillomavirus type 16 capsid antibodies among a cohort of university women.

To study the temporal relationship between serum antibody response and human papillomavirus type 16 (HPV-16) infection, a cohort of 325 university women were scheduled for examinations at 4-month intervals. At every examination, interviews were completed, cells were obtained for polymerase chain reaction-based testing and for Pap screening, and serum was obtained for testing with a HPV-16 capsid-capture ELISA. Seroreactivity was associated with detection of HPV-16 DNA and with increased numbers of sex partners. The median time to seroconversion was 8.3 months among women with incident HPV-16 infections. Within 16 months following HPV-16 DNA detection, 93.7% of women with prevalent and 67.1% of women with incident infections seroconverted. After seroconversion, antibody responses were maintained during follow-up among HPV-16 DNA-positive women. Women who seroconverted were 5.7 times (95% confidence interval = 2.4-13.4) more likely to have squamous intraepithelial lesions associated with the detection of HPV-16 DNA than were women who did not seroconvert.

Surface conformational and linear epitopes on HPV-16 and HPV-18 L1 virus-like particles as defined by monoclonal antibodies.

A panel of 24 monoclonal antibodies (MAbs) was generated against human papillomavirus (HPV) types 16 and 18 L1 virus-like particles (VLPs). The MAbs were screened for reactivity to a variety of VLPs prepared from HPV-6, -11, -16, -18, -31, -33, -35, and -45, cottontail rabbit papillomavirus, bovine papillomavirus type 1, and a set of 35 overlapping 20-amino-acid peptides spanning the entire HPV-16 L1 gene. Type-specific linear and conformational surface epitopes were detected as well as several cross-reactive linear epitopes that showed various levels of cross-reactivity between different genital HPV and animal papillomavirus L1s. Most of the linear epitopes were mapped using synthetic peptides, and the epitopes were identified as being either surface or buried within the VLP as defined by the pattern of reactivity in ELISA using intact and disrupted VLP antigen. These MAbs may be useful reagents to help define neutralizing epitopes of HPV-16 and -18 when infectivity assays become available, and to define the regions of L1 that are exposed on the surface or buried within the assembled capsid.

The relationship of human papillomavirus-related cervical tumors to cigarette smoking, oral contraceptive use, and prior herpes simplex virus type 2 infection.

It has now been established that infection with human papillomavirus (HPV) is necessary for the development of most cervical cancers. HPV is not sufficient for the development of cancer. Other exposures or host factors are necessary for cancer to occur. As part of an ongoing, population-based case-control study of invasive cervical cancer, we investigated the role of cigarette smoking, oral contraceptive (OC) use, and herpes simplex virus type 2 (HSV-2) as potential cofactors with HPV in the development of cervical cancer. Residents of three counties in western Washington State who were diagnosed with invasive squamous cell cervical cancer (n = 314) from January 1986 through December 1992 were interviewed about their sexual, reproductive, contraceptive, and cigarette smoking histories. Similar information was obtained from control women identified through random digit dialing (n = 672). The sera from 206 cases and 522 controls were tested for both HPV 16 capsid antibodies and HSV-2 antibodies. PCR was used to test paraffin-embedded tumor tissues for the presence of HPV DNA types 6, 16, 18, 31, 33, 35, and 39. Women with cervical cancer were more likely to be current smokers at diagnosis than population controls [relative risk (RR), 2.5; 95% confidence interval (CI), 1.8-3.4]. The risk associated with smoking was present to a similar extent among women positive and negative for HPV as measured by HPV 16 capsid antibodies and HPV DNA in the tumor tissue (cases). OC use was only important if first use was at an early age, particularly ages < or = 17 years (RR, 2.3; 95% CI, 1.4-3.8). There was only a slight risk for cervical cancer associated with antibodies to HSV-2 (RR, 1.2; 95% CI, 0.9-1.7). However, when we stratified by markers of HPV exposure, we found a significant increase in risk associated with HSV-2 among women negative for HPV 16 antibodies (RR, 2.0; 95% CI, 1.3-3.0), which was strengthened when we confined our analysis to cases whose tumors were HPV DNA negative (RR, 3.6; 95% CI, 1.6-8.0). There was no indication that cigarette smoking, OC use, or HSV-2 infection influence the ability of HPV infection to cause invasive cervical cancer. OC use may only be important in the etiology of invasive squamous cell cervical tumors if the use occurs at a critical time in the development of a woman's reproductive tract, at ages < or = 17 years. The majority of risk associated with HSV-2 was confined to HPV-negative tumors, indicating a possible separate pathway to disease that may account for 5-10% of invasive cervical cancers.

Use of human papillomavirus type 6 capsids to detect antibodies in people with genital warts.

Human papillomavirus (HPV) type 6 capsids were produced by recombinant vaccinia viruses and used in a capture ELISA to screen 901 human sera from three studies of genital HPVs. The highest seroprevalence was observed among subjects with recurrent genital warts. In a population-based case-control study of genital warts, 26 (58%) of 45 women with recurrent genital warts were seropositive compared with 19 (19%) of 101 control women with no history of genital warts (odds ratio, 6.5; 95% confidence interval, 3.0, 14.1). Among a cohort of pregnant women, 7 (88%) of 8 with recurrent warts were seropositive compared with 24 (30%) of 79 pregnant women with no such history. A significant association between seropositivity to HPV-6 capsids and the detection of HPV-6/11 DNA from genital specimens by polymerase chain reaction was also observed. Men with genital warts were less likely to be seropositive than were women with genital warts, and a positive association between the number of sex partners and seropositivity was observed among only the female university students.

Immunization of mice with HPV vaccinia virus recombinants generates serum IgG, IgM, and mucosal IgA antibodies.

To assess the utility of vaccinia virus recombinants in the development of an immune response against HPV capsid antigens, 5-week-old C57B16 female mice were administered either purified HPV 1 capsids produced by a vaccinia virus recombinant or the recombinant vaccinia virus itself. Animals were boosted at Week 4 with either agent. Mice developed a serum IgG antibody response in all the administration protocols that was directed mainly against native L1 epitopes. Mice injected initially with the vaccinia virus recombinant and boosted with purified capsids had a higher titer antibody response (P = 0.024) with more mice responding to a greater extent. All mice produced a serum IgM response that preceded the IgG response by approximately 2 weeks and lasted 1-3 weeks. The IgM response was directed against native L1 epitopes. Although no serum IgA was detected, IgA could be detected in vaginal secretions of mice that were immunized or boosted with the vaccinia virus vector. These results indicate that an extensive humoral immune response to HPV can be elicited using vaccinia virus recombinants.