Local Cost-Effectiveness of Nasopharyngeal Carcinoma Screening Strategies in Southern China: Secondary Analysis of the PRO-NPC-001 Cluster-Randomized Trial

PURPOSE/OBJECTIVE(S)

Population-based screening for endemic nasopharyngeal carcinoma (NPC) detects most cases at an early stage. In a cluster-randomized trial conducted in Guangdong, a combination of Epstein-Barr Virus (EBV) anti-VCA/EBNA1 IgA serology and endoscopy reduced NPC mortality. We conducted a secondary analysis of this trial in conjunction with local incidence and cost data, hypothesizing that screening would be cost-effective in this region.

MATERIALS/METHODS

We estimated population-level NPC mortality reduction, resource utilization, and cost-effectiveness of 12 unique screening strategies in six populations in Guangdong/Guangxi using a previously-validated time-inhomogeneous decision-analytic cohort model. These 12 strategies evaluated combinations of serology, nasopharyngeal swab PCR (NP PCR), endoscopy, and head/neck MRI. Incidence data, screening costs, and healthcare costs were obtained from local cancer registries, laboratories conducting ELISA/PCR, and the Guangdong provincial healthcare system. We evaluated variable screening ages, sexes, intervals, and durations to identify optimal screening approaches from the perspective of the healthcare system in southern China. An incremental cost-effectiveness ratio (ICER) willingness-to-pay threshold of 1.50 times the per-capita GDP was considered cost-effective in southern China.

RESULTS

For the base strategy screening 50-year-old men and women using only serology and endoscopy, the average cost per screened subject for a single round of screening over a five-year cycle was ¥175.69. The addition of MRI improved sensitivity (76% vs. 62%) and approximately doubled screening costs. Triage with NP PCR was cost-neutral when used in conjunction with MRI and reduced endoscopy/MRI utilization by 37% with a 3-4% reduction in screening sensitivity. Among 50-year-old men and women, screening was cost-effective in all populations provided that medium-risk subjects were not referred for endoscopy/MRI (ICER/GDP 0.62-0.83). The use of NP PCR without MRI (ICER/GDP 0.83) was dominated by the base strategy (ICER/GDP 0.62) due to higher costs and NPC mortality. After a single five-year screening cycle, screening reduced population NPC mortality by 14% with serology + endoscopy and 21% with serology + endoscopy + MRI. Introduction of MRI with or without NP PCR could be cost-effective in all populations. For MRI-based strategies, the most efficient use of resources was deferral of endoscopy unless MRI was abnormal (ICER/GDP 0.67). Overall, the best-performing strategies balanced NPC mortality, screening costs, and MRI utilization.

CONCLUSION

EBV serology-based screening for endemic NPC is likely to be cost-effective among adult men and women in Guangdong and Guangxi. Referring medium-risk subjects for endoscopy/MRI should be avoided, and NP PCR should be used to triage individuals for MRI rather than endoscopy. These data may aid the design of population-based screening programs in this region.

[Germany-wide, Web-based ParaReg Registry for Lifelong Monitoring of People with Spinal Cord Injury: Data Model, Ethico-legal Prerequisites and Technical Implementation]

OBJECTIVE

In Germany, treatment paths for patients with acute spinal cord injury (SCI) differ considerably depending on intrinsic, disease-specific and extrinsic factors. Which of these factors are associated with improved outcome with fewer subsequent complications and inpatient re-admissions is not clear. The German-wide, patient-centered, web-based ParaReg registry will be implemented to improve the long-term quality of patient care and the planning of treatment paths with increased cost-effectiveness.

METHODS

In the 2017-18 conceptualization phase, the data model of the registry was developed in an iterative process of the ParaReg steering committee together with the extended DMGP board and patient representatives. In ParaReg, routine social and medical data as well as internationally established neurological, functional and participation scores will be documented. The assignment of a unique patient ID allows a lifelong, cross-center documentation of inpatient stays in one of the 27 SCI centers organized in the German-speaking Medical Society for SCI (DMGP). The ParaReg data protection concept and patient information/consent are based on the Open Source Registry for Rare Diseases (OSSE) which were extended by GDPR-relevant aspects.

RESULTS

In the realization phase, which started in 2019, the information technology infrastructure was implemented according to the clinical ID management module of the Technology and Methods Platform for Networked Medical Research (TMF). In parallel, the legal and ethical prerequisites for registry operation under the patronage of the DMGP were created. Recommendations of the working group data protection of the TMF were integrated into ParaReg's data protection concept. Based on the feedback from the alpha test phase with documentation of the hospitalization data of 40 patients, the ergonomics of the electronic case report forms were improved in particular for data entry on mobile devices.

CONCLUSION

After completion of the monocentric alpha test phase, the multicenter data acquisition was started in 5 DMGP-SCI centers. The sustainability of ParaReg is ensured by the structural and financial support of the DMGP after expiry of the funding by the German Federal Ministry of Education and Research (BMBF).

Timing of HPV16-E6 antibody seroconversion before OPSCC: findings from the HPVC3 consortium

BACKGROUND

Human papillomavirus type 16 (HPV16)-E6 antibodies are detectable in peripheral blood before diagnosis in the majority of HPV16-driven oropharyngeal squamous cell carcinoma (OPSCC), but the timing of seroconversion is unknown.

PATIENTS AND METHODS

We formed the HPV Cancer Cohort Consortium which comprises nine population cohorts from Europe, North America and Australia. In total, 743 incident OPSCC cases and 5814 controls provided at least one pre-diagnostic blood sample, including 111 cases with multiple samples. Median time between first blood collection and OPSCC diagnosis was 11.4 years (IQR = 6-11 years, range = 0-40 years). Antibodies against HPV16-E6 were measured by multiplex serology (GST fusion protein based Luminex assay).

RESULTS

HPV16-E6 seropositivity was present in 0.4% of controls (22/5814; 95% CI 0.2% to 0.6%) and 26.2% (195/743; 95% CI 23.1% to 29.6%) of OPSCC cases. HPV16-E6 seropositivity increased the odds of OPSCC 98.2-fold (95% CI 62.1-155.4) in whites and 17.2-fold (95% CI 1.7-170.5) in blacks. Seropositivity in cases was more frequent in recent calendar periods, ranging from 21.9% pre-1996 to 68.4% in 2005 onwards, in those with blood collection near diagnosis (lead time <5 years). HPV16-E6 seropositivity increased with lead time: 0.0%, 13.5%, 23.7%, and 38.9% with lead times of >30 years (N = 24), 20-30 years (N = 148), 10-20 years (N = 228), and <10 years (N = 301 cases) (p-trend < 0.001). Of the 47 HPV16-E6 seropositive cases with serially-collected blood samples, 17 cases seroconverted during follow-up, with timing ranging from 6 to 28 years before diagnosis. For the remaining 30 cases, robust seropositivity was observed up to 25 years before diagnosis.

CONCLUSIONS

The immune response to HPV16-driven tumorigenesis is most often detectable several decades before OPSCC diagnosis. HPV16-E6 seropositive individuals face increased risk of OPSCC over several decades.

Circulating levels of immune and inflammatory markers and long versus short survival in early-stage lung cancer

BACKGROUND

Some patients diagnosed with early-stage lung cancer and treated according to standard care survive for only a short period of time, while others survive for years for reasons that are not well understood. Associations between markers of inflammation and survival from lung cancer have been observed.

MATERIALS AND METHODS

Here, we investigate whether circulating levels of 77 inflammatory markers are associated with long versus short survival in stage I and II lung cancer. Patients who had survived either <79 weeks (~1.5 years) (short survivors, SS) or >156 weeks (3 years) (long survivors, LS) were selected from a retrospective population-based study. Logistic regression was used to calculate adjusted odds ratios (ORs) and corresponding 95% confidence intervals (CIs). The false discovery rate was calculated to adjust for multiple testing.

RESULTS

A total of 157 LS and 84 SS were included in this analysis. Thirteen markers had adjusted OR on the order of 2- to 5-fold when comparing the upper and lower quartiles with regard to the odds of short survival versus long. Chemokine CCL15 [chemokine (C-C motif) ligand 15] was the most significant marker associated with increased odds of short survival (ORs = 4.93; 95% CI 1.90-12.8; q-value: 0.042). Smoking and chronic obstructive pulmonary disease were not associated with marker levels.

CONCLUSIONS

Our results provide some evidence that deregulation of inflammatory responses may play a role in the survival of early-stage lung cancer. These findings will require confirmation in future studies.

Correlates of anti-EBV EBNA1 IgA positivity among unaffected relatives from nasopharyngeal carcinoma multiplex families

Background:

To determine whether non-viral nasopharyngeal carcinoma (NPC) risk factors might be associated with (and mediated through) Epstein–Barr virus (EBV) serological responses linked to NPC risk, we evaluated predictors of risk of anti-EBNA1 IgA seropositivity and other markers among unaffected relatives from a large NPC family study in Taiwan.

Methods:

Multivariate logistic regression conditioned on family was used to examine the associations between sociodemographic, dietary, lifestyle, and occupational variables and risk of anti-EBV EBNA1 IgA positivity, anti-VCA IgA, and anti-DNase positivity.

Results:

Among 2393 unaffected relatives from 319 multiplex families, 1180 (49.3%) were anti-EBV EBNA1 IgA seropositive. None of the associations with anti-EBNA1 IgA were statistically significant, except for being 31–50 years of age (vs <30, adjusted ORs 0.51–0.57). For one or more EBV serological markers, there were suggestive associations for older age, GuangDong firm salted fish, betel use, current alcohol use, and male gender.

Conclusion:

Overall, we found little evidence to suggest that non-viral NPC risk factors significantly alter EBV serological patterns, suggesting that non-viral NPC risk factors act through pathways independent of EBV serological responses.

A first report on Hb Q-Iran in association with alpha-thalassemia in a case of spinal ischemia

BACKGROUND

Hemoglobin Q-Iran is a rare variant which has not been described in association with alpha-thalassemia to date. We present the case of a Turkish patient who developed spinal ischemia.

METHODS

Spinal ischemia was diagnosed clinically, via magnetic resonance imaging and angiographically. Blood samples were analyzed by high performance liquid chromatography, electrophoresis, gene sequencing, hematological and biochemical analysis.

RESULTS

We detected hemoglobin Q-Iran in association with alpha-thalassemia. The same hemoglobinopathy was detected in two members of the patient's family.

CONCLUSIONS

As various differential diagnosis approaches failed to reveal the cause of spinal ischemia, the combined hemoglobinopathy was eventually postulated.

Human leukocyte antigen class I and II haplotypes and risk of cervical cancer

Human leukocyte antigen (HLA) variations may affect immune response to human papillomavirus infection and subsequent cervical neoplasia risk. We investigated the frequency and relationship between HLA-A-B and HLA-A-B-DR haplotypes among women with cervical cancer/high-grade lesions (n=365) and cytologically normal population controls (n=681) within three cervical neoplasia studies in the US and Costa Rica. Notable differences in haplotype frequencies were observed; the HLA-A*01-B*08 haplotype occurred in >5% of US Caucasians but in <1% of Costa Ricans. The most prevalent HLA-A*24-B*40-DR*04 haplotype in Costa Rica (5%) was found in <1% of US Caucasians. No HLA haplotype was significantly associated with cervical neoplasia, suggesting that individual allele associations reported to date (e.g. HLA-DR*13) are not likely explained by underlying haplotypes.

Determinants of human papillomavirus 16 serological conversion and persistence in a population-based cohort of 10 000 women in Costa Rica

Determinants of human papillomavirus (HPV)-16 serological conversion and persistence were assessed in a population-based cohort of 10 049 women in Guanacaste, Costa Rica. Serologic responses to HPV-16 were measured in 7986 women by VLP-based enzyme-linked immunosorbent assay at both study enrolment (1993/94) and at 5–7 years of follow-up. Seropositive women were defined as ⩾5 standard deviations above the mean optical density obtained for studied virgins at enrolment (n=573). Seroconnversion (n=409), persistence (n=675), and clearance (n=541) were defined based on enrolment and follow-up serology measurements. Age-specific distributions revealed that HPV-16 seroconversion was highest among 18- to 24-year-old women, steadily declining with age; HPV-16 seropersistence was lowest in women 65+ years. In age-adjusted multivariate logistic regression models, a 10-fold risk increase for HPV-16 seroconversion was associated with HPV-16 DNA detection at enrolment and follow-up; two-fold risk of seroconversion to HPV-16 was associated with increased numbers of lifetime and recent sexual partners and smoking status. Determinants of HPV-16 seropersistence included a 1.5-fold risk increase associated with having one sexual partner during follow-up, former oral contraceptive use, and a 3-fold risk increase associated with HPV-16 DNA detection at both enrolment and follow-up. Higher HPV-16 viral load at enrolment was associated with seroconversion, and higher antibody titres at enrolment were associated with seropersistence.

A case-control study of endogenous hormones and cervical cancer

Both parity and oral contraceptive use are associated with elevated circulating levels of sex hormones, at least transiently, and with increased risk of cervical cancer in human papillomavirus (HPV)-infected women. We directly evaluated whether elevations in the physiologic levels of these hormones predispose to the development of cervical neoplasia. We identified 67 premenopausal and 43 postmenopausal women with cervical intraepithelial neoplasia 2, 3, or cervical cancer (>/=CIN2) diagnosed during enrollment of a population-based cohort of 10 077 women. Four controls, two chosen randomly and two chosen from women testing positive for cancer-associated HPV, were matched to each case on menopausal status, age, days since last menses (pre), or years since menopause (post). Sex hormone-binding globulin, oestradiol, oestrone, oestrone-sulphate, dehydroepiandrosterone sulphate, and progesterone were measured in enrollment plasma. There was no consistent association between the sex hormones and risk of >/=CIN2. Excluding cases with invasive disease had a minimal impact on results. Though this case-control study was based on a well-defined population, it was limited by reliance on a single measure of hormone levels taken at the time of diagnosis. Nonetheless, our results do not support the hypothesis that plasma levels of sex hormones have an important bearing on the risk of cervical neoplasia in HPV-infected women.

A population based study of herpes simplex virus 2 seroprevalence in rural Costa Rica

OBJECTIVES

To determine seroprevalence and determinants of herpes simplex virus 2 (HSV-2) seropositivity, in a random sample of a population based cohort of 10 049 women of Guanacaste, Costa Rica, using a highly sensitive and specific serological assay.

METHODS

Seroprevalence was determined by a type specific HSV-2 ELISA assay in an age stratified random sample of 1100 women. Univariate and multivariate logistic regression was used to calculate odds ratios and 95% confidence intervals for risk factors of seropositivity.

RESULTS

Overall age adjusted HSV-2 seroprevalence was 38.5% (95% CI, 37.5 to 39.5), and it was strongly associated with increasing age (p(Trend<0.0001)), both among monogamous women and women with multiple sexual partners. A greater number of lifetime sexual partners increased the risk of seropositivity, with a 28.2% (95% CI, 24.4 to 32.2) seroprevalence among monogamous women and 75% (95% CI, 65.6 to 83.0) seroprevalence for those with four or more partners (OR = 7.6 95% CI, 4.7 to 12.4 p(Trend<0.0001)). Barrier contraceptive use was negatively associated with HSV-2 seropositivity (OR 0.54, 95% CI, 0.31 to 0.94). Women with antibodies against HPV 16, 18, or 31 were 1.6 times more likely to be HSV-2 seropositive (OR 1.6, 95% CI, 1.2 to 2.1).

CONCLUSIONS

HSV-2 infection is highly endemic in Guanacaste, even among lifetime monogamous women, suggesting a role of male behaviour in the transmission of the infection. Until vaccination against HSV-2 is available, education to prevent high risk sexual behaviour and the use of condoms appear as preventive measures against HSV-2.

Seroprevalence of human papillomavirus-16, -18, -31, and -45 in a population-based cohort of 10000 women in Costa Rica

Human papillomavirus (HPV) seroprevalence and determinants of seropositivity were assessed in a 10049-woman population-based cohort in Guanacaste, Costa Rica. Serologic responses based on VLP-based ELISA were obtained from the plasma collected at study enrollment in 1993/1994 for HPV-16 (n=9949), HPV-18 (n=9928), HPV-31 (n=9932), and HPV-45 (n=3019). Seropositivity was defined as five standard deviations above the mean optical density obtained for studied virgins (n=573). HPV-16, -18, -31, and -45 seroprevalence was 15, 15, 16, and 11%, respectively. Of women DNA-positive for HPV-16, -18, -31, or -45, seropositivity was 45, 34, 51, and 28%, respectively. Peak HPV seroprevalence occurred a decade after DNA prevalence; lifetime number of sexual partners was the key determinant of seropositivity independent of DNA status and age. DNA- and sero-positive women showed the highest risk for concurrent CIN3/cancer, followed by DNA-positive, sero-negative women.

Metabolic gene polymorphism frequencies in control populations

Using the International Project on Genetic Susceptibility to Environmental Carcinogens (GSEC) database containing information on over 15,000 control (noncancer) subjects, the allele and genotype frequencies for many of the more commonly studied metabolic genes (CYP1A1, CYP2E1, CYP2D6, GSTM1, GSTT1, NAT2, GSTP, and EPHX) in the human population were determined. Major and significant differences in these frequencies were observed between Caucasians (n = 12,525), Asians (n = 2,136), and Africans and African Americans (n = 996), and some, but much less, heterogeneity was observed within Caucasian populations from different countries. No differences in allele frequencies were seen by age, sex, or type of controls (hospital patients versus population controls). No examples of linkage disequilibrium between the different loci were detected based on comparison of observed and expected frequencies for combinations of specific alleles.

Human leukocyte antigen class I and II alleles and risk of cervical neoplasia: results from a population-based study in Costa Rica

To examine human leukocyte antigen (HLA) involvement in the development of all grades of cervical neoplasia, a nested case-control study of 10,077 women in Guanacaste, Costa Rica, was conducted. Participants had invasive cervical cancer, high-grade squamous intraepithelial lesions (HSILs; n=166), or low-grade squamous intraepithelial lesions (LSILs); were positive for human papillomavirus (HPV) with no evidence of cervical neoplasia (n=320); or were HPV negative with no evidence of cervical neoplasia but with a history of high-risk sexual behavior (n=173). Compared with women who were HPV negative, women with HLA-DRB1*1301 were associated with decreased risk for cancer/HSILs (odds ratio [OR], 0.4; 95% confidence interval [CI], 0.2-0.7) and for LSILs/HPV (OR, 0.6; 95% CI, 0.3-0.9). Women with both HLA-B*07 and HLA-DQB1*0302 had an 8.2-fold increased risk for cancer/HSILs (95% CI, 1.8-37.2) and a 5.3-fold increased risk for LSILs/HPV (95% CI, 1.2-23.7). These results support the hypothesis that multiple risk alleles are needed in order to increase risk for cervical neoplasia, but a single protective allele may be sufficient for protection.

Occupational exposure to wood, formaldehyde, and solvents and risk of nasopharyngeal carcinoma

Our objective was to evaluate the link between occupational exposures to wood dust, formaldehyde, and solvents and the development of nasopharyngeal carcinoma (NPC). A case-control study was conducted among 375 newly diagnosed cases of NPC in Taipei, Taiwan, and 325 community controls matched to cases on sex, age, and geographical residence (99 and 87% response rates, respectively). Most cases (>90%) were diagnosed with WHO Types 2 or 3 (nonkeratinizing and undifferentiated carcinomas), whereas the remaining cases were diagnosed with WHO Type 1 (squamous cell carcinomas). A complete occupational history was obtained via a personal interview and blindly assessed by an industrial hygienist for intensity and probability of exposure to wood dust, formaldehyde, and solvents. Information on socio-demographic characteristics, cigarette smoking, dietary consumption of nitrosamines, and other potential confounding factors was obtained via a personal interview. Blood specimens were tested for human leukocyte antigen class I/II genotypes, polymorphisms in cytochrome P450 2E1 genotype, and various anti-EBV antibodies known to be associated with NPC. Analysis was performed using logistic regression; relative risk (RR) estimates and 95% confidence intervals (CI) were calculated. Individuals exposed to wood dust had an adjusted RR of 1.7 (95% CI = 1.0-3.0). Those exposed to wood dust for >10 years had an adjusted RR of 2.4 (95% CI = 1.1-5.0; p(trend) = 0.02). Risk was strongest for those first exposed before the age of 25 years and those seropositive to EBV. Individuals exposed to formaldehyde were at a more modest and nonsignificant increased risk of NPC (RR = 1.4; 95% CI = 0.93-2.2). Those exposed to formaldehyde for >10 years had an adjusted RR of 1.6 (95% CI = 0.91-2.9). The association between formaldehyde and NPC was stronger in analyses restricted to EBV seropositive individuals (RR = 2.7; 95% CI = 1.2-5.9). However, no dose response was observed with increasing duration or cumulative use. No association was observed between solvent exposure and NPC (RR = 1.2; 95% CI = 0.86-1.7). Occupational exposure to wood dust is likely to be involved in the development of NPC, a finding that is consistent with the known link between wood exposure and nasal adenocarcinomas. Formaldehyde exposure is less clearly linked to NPC, whereas exposure to solvents is unlikely to be involved in NPC pathogenesis.

An association of cervical inflammation with high-grade cervical neoplasia in women infected with oncogenic human papillomavirus (HPV)

Previous reports of genital conditions, such as nonspecific genital infection/sore or vaginal discharge associated with cervical cancer (L. A. Brinton et al., J. Natl. Cancer Inst. (Bethesda), 79: 23-30, 1987; C. J. Jones et al., Cancer Res., 50: 3657-3662, 1990), suggest a possible link between either genital tract inflammation or changes in bacteria flora consistent with bacterial vaginosis (BV) and cervical cancer. To test whether changes in vaginal bacterial flora or the degree of cervical inflammation are associated with women having a human papillomavirus (HPV) infection or with women infected with oncogenic HPV having high-grade cervical lesions (high-grade squamous intraepithelial lesions or cancer), we conducted a case-control study of women <50 years old enrolled in the Costa Rican natural history study of HPV and cervical neoplasia. To test whether BV and inflammation were associated with HPV DNA positivity, Analysis 1 was restricted to women with no or mild (low-grade or equivocal) cytological abnormalities, and the degree of inflammation and Nugent score (a measure of BV) were compared between women infected (n = 220) and not infected (n = 130) with HPV. To test whether BV and inflammation were associated with high-grade lesions, Analysis 2 was restricted to women infected with oncogenic HPV, and the degree of inflammation and Nugent score were compared between women with (n = 95) and without (n = 158) high-grade cervical lesions. In Analysis 1, BV and cervical inflammation were not associated with HPV infection. In Analysis 2, BV was not associated with high-grade lesions. However, we found a marginally significant positive trend of increasing cervical inflammation associated with high-grade lesions in oncogenic HPV-infected women, (P(trend) = 0.05). Overt cervicitis was associated with a 1.9-fold increase in risk of high-grade lesions (95% confidence interval, 0.90-4.1). The results of this study suggest that cervical inflammation may be associated with high-grade lesions and may be a cofactor for high-grade cervical lesions in women infected with oncogenic HPV.

HPV co-factors related to the development of cervical cancer: results from a population-based study in Costa Rica

We examined factors associated with high-grade squamous intraepithelial lesions (HSIL) and cervical cancer among human papillomavirus (HPV)-infected women in a prevalent case-control study conducted within a population-based cohort of 10 077 women in Costa Rica. We compared 146 women with HPV-positive HSIL or cancer (HSIL/CA) against 843 HPV-positive women without evidence of HSIL/CA. Subjects completed a risk factor questionnaire. We evaluated the associations between exposures and HSIL/CA among women positive for any HPV and restricted to those positive for high-risk HPV types. Risk of HSIL/CA increased with increasing number of live births (P(trend)= 0.04). Women who smoked 6+ cigarettes/day had a RR for HSIL/CA of 2.7 (95% CI = 1.1-6.7) compared to non-smokers. Current use of barrier contraceptives was associated with a reduction in risk of HSIL/CA (RR = 0.39; 95% CI = 0.16-0.96). Sexual behaviour and a self-reported history of sexually transmitted diseases (STDs) other than HPV were not associated with HSIL/CA. Oral contraceptive use was associated with HSIL/CA among women with <3 pregnancies. Effects were similar in analysis restricted to women positive for high-risk HPV types. Among women positive for high-risk HPV types, 44% of HSIL/CA could be attributed to multiparity (>/=3 pregnancies) and/or smoking. Among HPV-positive women, multiparity and smoking are risk factors for HSIL/CA. Oral contraceptive use may be associated with HSIL/CA in subgroups of women.

Clinical trial designs for the early clinical development of therapeutic cancer vaccines

There are major differences between therapeutic tumor vaccines and chemotherapeutic agents that have important implications for the design of early clinical trials. Many vaccines are inherently safe and do not require phase I dose finding trials. Patients with advanced cancers and compromised immune systems are not good candidates for assessing either the toxicity or efficacy of therapeutic cancer vaccines. The rapid pace of development of new vaccine candidates and the variety of possible adjuvants and modifications in method of administration makes it important to use efficient designs for clinical screening and evaluation of vaccine regimens. We review the potential advantages of a wide range of clinical trial designs for the development of tumor vaccines. We address the role of immunological endpoints in early clinical trials of tumor vaccines, investigate the design implications of attempting to use disease stabilization as an end point and discuss the difficulties of reliably utilizing historical control data. Several conclusions for expediting the clinical development of effective cancer vaccines are proposed.

Safety and immunogenicity trial in adult volunteers of a human papillomavirus 16 L1 virus-like particle vaccine

BACKGROUND

Studies in animal models have shown that systemic immunization with a papillomavirus virus-like particle (VLP) vaccine composed of L1, a major structural viral protein, can confer protection against subsequent experimental challenge with the homologous virus. Here we report results of a double-blind, placebo-controlled, dose-escalation trial to evaluate the safety and immunogenicity of a human papillomavirus (HPV) type 16 (HPV16) L1 VLP vaccine in healthy adults.

METHODS

Volunteers were given intramuscular injections with placebo or with 10- or 50-microg doses of HPV16 L1 VLP vaccine given without adjuvant or with alum or MF59 as adjuvants at 0, 1, and 4 months. All vaccine recipients were monitored for clinical signs and symptoms for 7 days after each inoculation. Immune responses were measured by an HPV16 L1 VLP-based enzyme-linked immunosorbent assay (ELISA) and by an HPV16 pseudovirion neutralization assay. The antibody titers were given as the reciprocals of the highest dilution showing positive reactivity in each assay. All statistical tests were two-sided.

RESULTS

The prevaccination geometric mean ELISA titer for six seropositive individuals was 202 (range, 40--640). All vaccine formulations were well tolerated, and all subjects receiving vaccine seroconverted. Serum antibody responses at 1 month after the third injection were dose dependent in recipients of vaccine without adjuvant or with MF59 but were similar at both doses when alum was the adjuvant. With the higher dose, the geometric means of serum ELISA antibody titers (95% confidence intervals) to purified VLP 1 month after the third injection were as follows: 10,240 (1499 to 69 938) without adjuvant, 10,240 (1114 to 94 145) with MF59, and 2190 (838 to 5723) with alum. Responses of subjects within each group were similar. Neutralizing and ELISA antibody titers were highly correlated (Spearman correlation =.85), confirming that ELISA titers are valid proxies for neutralizing antibodies.

CONCLUSIONS

The HPV16 L1 VLP vaccine is well tolerated and is highly immunogenic even without adjuvant, with the majority of the recipients achieving serum antibody titers that were approximately 40-fold higher than what is observed in natural infection.

Associations between smoking and adenocarcinomas and squamous cell carcinomas of the uterine cervix (United States)

OBJECTIVES

Few studies of smoking and cervical carcinoma have addressed the rare cervical adenocarcinomas or used DNA-based tests to control for human papillomavirus (HPV) infection.

METHODS

This multicenter case-control study included 124 adenocarcinoma cases, 307 community controls (matched on age, race, and residence to adenocarcinoma cases), and 139 squamous carcinoma cases (matched on age, diagnosis date, clinic, and disease stage to adenocarcinoma cases). Participants completed risk-factor interviews and volunteered cervical samples for PCR-based HPV testing. Polychotomous logistic regression generated adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for both histologic types.

RESULTS

Eighteen percent of adenocarcinoma cases, 43% of squamous carcinoma cases, and 22% of controls were current smokers. After control for HPV and other questionnaire data, adenocarcinomas were consistently inversely associated with smoking (e.g. current: OR = 0.6, 95% CI 0.3-1.1; > or = 1 pack per day: OR = 0.7, 95% CI 0.4-1.3), while squamous carcinomas were positively associated with smoking (e.g. current: OR = 1.6, 95% CI 0.9-2.9; > or = 1 pack per day: OR = 1.8, 95% CI 1.0-3.3). Results in analyses restricted to HPV-positive controls were similar.

CONCLUSION

Smoking has opposite associations with cervical adenocarcinomas and squamous carcinomas. Although both histologic types are caused by HPV and arise in the cervix, etiologic co-factors for these tumors may differ.

Evaluation of self-collected cervicovaginal cell samples for human papillomavirus testing by polymerase chain reaction

As human papillomavirus (HPV) becomes accepted as the central cause of cervical cancer, longitudinal studies are shifting focus away from causality to a more detailed investigation of the natural history of HPV infections. These studies commonly require repeated samples for HPV testing over several years, usually collected during a pelvic exam, which is inconvenient to the participants and costly to the study. To alleviate the inconvenience and cost of repeated clinic visits, it has been proposed that women collect cervicovaginal cells themselves, hopefully increasing participation in the natural history studies. We evaluated the technical feasibility of self-collection of cervicovaginal cells using a Dacron swab for HPV DNA detection. We compared the self-collected swab sample and two clinician-administered swab samples (one from the endocervix and another from the ectocervix) from a total of 268 women participating in a case-control study of adenocarcinoma and squamous cell carcinomas of the uterine cervix (111 cases and 157 controls). HPV DNA was detected and genotyped using an L1 consensus PCR assay. The overall agreement between the clinician- and self-collected swabs was excellent [88.1%; kappa = 0.73 (95% confidence interval (CI), 0.61-0.85)]. The correlation was highest between the two clinician-administered swabs [kappa = 0.81 (95% CI, 0.69-0.93)] but was still excellent when comparing either clinician-administered swab to the self-administered sample [kappa = 0.75 (95% CI, 0.63-0.87) and 0.67 (95% CI, 0.55-0.79) for ectocervix and endocervix, respectively]. The type-specific agreement between samples was higher for high-risk, or cancer-associated, HPV genotypes than for low risk, noncancer-associated HPV genotypes when comparing the self-administered swab sample to the clinician-administered swab sample (kappa = 0.78 for high-risk versus 0.66 for low-risk HPV infections, t = -1.45, P = 0.15). The decrease in agreement for low risk types was largely attributable to an increased detection of these types in the self-administered sample (McNemar's chi2 = 6.25, P = 0.01 for clinician- versus self-administered swab comparisons). The agreement did not vary significantly by age, menopausal status, case status, or clinic center. We have demonstrated that a self-collected Dacron swab sample of cervicovaginal cells is a technically feasible alternative to clinician-administered cervical cell collection in natural history studies of HPV and cervical cancer.

A prospective study of human papillomavirus (HPV) type 16 DNA detection by polymerase chain reaction and its association with acquisition and persistence of other HPV types

Human papillomavirus (HPV)-16 causes about half the cases of cervical cancer worldwide and is the focus of HPV vaccine development efforts. Systematic data are lacking as to whether the prevention of HPV-16 could affect the equilibrium of infection with other HPV types and thus alter the predicted impact of vaccination on the occurrence of cervical neoplasia. Therefore, the associations of HPV-16 detection with subsequent acquisition of other HPV types and with the persistence of concomitantly detected HPV types were examined prospectively among 1124 initially cytologically normal women. Preexisting HPV-16 was generally associated with an increased risk for subsequent acquisition of other types. HPV-16 did not affect the persistence of concomitant infections, regardless of type. These findings suggest that the prevention or removal of HPV-16 is not likely to promote the risk of infection with other types, a theoretical concern with current vaccination efforts.

Dietary exposure to nitrite and nitrosamines and risk of nasopharyngeal carcinoma in Taiwan

Previous studies of nasopharyngeal carcinoma (NPC) have found elevated risks with higher consumption of salted fish and preserved foods, particularly during childhood. These foods can contain high levels of nitrosamines; however, most studies have not estimated exposure to nitrosamines directly. We conducted a case-control study in Taiwan to evaluate dietary intakes and NPC risk. A total of 375 cases (99% response rate) and 327 controls (88% response rate) were interviewed about their diet as an adult and at age 10 using a food-frequency questionnaire. We interviewed mothers of participants about their child's diet at age 10, age 3 and during weaning and the mother's diet while she was breast-feeding. Mothers of 96 cases and 120 controls were interviewed. Nitrosamine and nitrite levels were assigned to 66 foods based on published values. Intake of nitrosamines and nitrite as an adult was not associated with risk of NPC. High intakes of nitrosamines and nitrite during childhood and weaning were associated with increased risks of NPC for foods other than soy products. Adjusted odds ratios for the highest quartile were 2.2 [95% confidence interval (CI) 0.8-5.6] for age 10, 2.6 (95% CI 1.0-7.0) for age 3 and 3.9 (95% CI 1.4-10.4) for weaning diet. Intakes of nitrite and nitrosamines from soybean products during childhood and weaning were inversely associated with risk. Soybeans contain known inhibitors of nitrosation, and thus may explain the inverse association we observed. Our results suggest that nitrosamine and nitrite intake during childhood may play a role in the development of NPC.

Use of hormone replacement therapy and adenocarcinomas and squamous cell carcinomas of the uterine cervix

INTRODUCTION

Exogenous hormones may influence the development of cervical adenocarcinomas. Incidence rates of adenocarcinomas and use of noncontraceptive hormones have increased since the 1970s, but few studies have investigated this potential relationship.

METHODS

We conducted a multicenter case-control study of 124 women with adenocarcinomas, 139 women with squamous cell carcinomas matched on age, diagnosis date, clinic, and stage of disease (in situ or invasive) to adenocarcinoma cases, and 307 healthy community controls who were also matched on age, ethnicity, and residence to adenocarcinoma cases. Participants completed in-person interviews regarding exogenous hormone use before diagnosis and other risk factors and volunteered cervical samples for human papillomavirus (HPV) testing via a PCR-based method. Odds ratios (ORs) with 95% confidence intervals (CIs) estimated relative risks.

RESULTS

Only 13 adenocarcinoma cases (10.5%), 7 squamous carcinoma cases (5%), and 20 controls (6.5%) had used noncontraceptive hormones for menopausal symptoms, irregular periods, or disease prevention; most use was short-term, former use. Ever-use was associated with adenocarcinomas (OR = 2.1, 95% CI 0.95-4.6) but not squamous carcinomas (OR = 0.85, 95% CI 0.34-2.1). No trends were seen with duration of use or ages at first use, but unopposed estrogens were positively associated with adenocarcinomas (OR = 2.7). Unopposed estrogens remained associated with adenocarcinomas (OR = 2.0) when analyses were restricted to the HPV-positive controls. Menopausal status was not associated with adenocarcinomas or squamous carcinomas and did not modify the other associations.

CONCLUSION

Although small numbers warrant tentative conclusions, exogenous estrogens, especially unopposed estrogens, were positively associated with adenocarcinomas. Noncontraceptive hormones were negatively but weakly associated with squamous carcinomas.

Population-based study of human papillomavirus infection and cervical neoplasia in rural Costa Rica

BACKGROUND

Human papillomavirus (HPV) is the main cause of cervical neoplasia. Because few population-based studies have investigated the prevalence of type-specific infection in relation to cervical disease, we studied a high-risk population, estimating the prevalence of HPV infection and the risk associated with various HPV types.

METHODS

We screened 9175 women in Guanacaste, Costa Rica, to obtain a referent standard final diagnosis, and tested 3024 women for more than 40 types of HPV with a polymerase chain reaction-based system.

RESULTS

Among women with normal cytology, HPV infections peaked first in women younger than 25 years, and they peaked again at age 55 years or older with predominantly non-cancer-associated types of HPV and uncharacterized HPV types. Low-grade squamous intraepithelial lesions (LSILs) (n = 189) decreased consistently with age. The prevalence of high-grade squamous intraepithelial lesions (HSILs) (n = 128) peaked first around age 30 years and again at age 65 years or older. Seventy-three percent of LSILs were HPV positive, with HPV16 being the predominant type (16% of positive subjects). HPV was found in 89% of HSILs and 88% of cancers, with HPV16 being strongly predominant (51% and 53% of positive subjects). Virtually all HSILs and cancers had cancer-associated HPV types, with high odds ratios (ORs) and attributable fractions around 80%. Risk for HPV16 was particularly high (OR for HSILs = 320, 95% confidence interval [CI] = 97-1000; OR for cancer = 710, 95% CI = 110-4500).

CONCLUSIONS

We confirm the early decline of HPV infection with age but note increased prevalence after menopause, which could be related to a second peak of HSILs, an observation that warrants further investigation. At least 80% of HPVs involved in cervical carcinogenesis in this population have been characterized. Polyvalent vaccines including the main cancer-associated HPV types may be able to prevent most cases of cervical disease in this region.

HPV DNA testing in cervical cancer screening: results from women in a high-risk province of Costa Rica

CONTEXT

Human papillomaviruses (HPVs) are known to cause most cervical cancer worldwide, but the utility of HPV DNA testing in cervical cancer prevention has not been determined.

OBJECTIVE

To provide comprehensive data on the screening performance of HPV testing for the most common carcinogenic types, at different levels of analytic sensitivity.

DESIGN

Laboratory analysis conducted during 1993-1995, using 3 cytologic techniques and cervicography, followed by colposcopic examination of women with any abnormal cervical finding, to detect all high-grade intraepithelial lesions and cancer (reference standard of clinically significant disease). The HPV testing was performed subsequently with masking regarding clinical findings.

SETTING

Guanacaste Province, Costa Rica, a region with a high age-adjusted incidence of cervical cancer.

PARTICIPANTS

Of 11742 randomly selected women, 8554 nonpregnant, sexually active women without hysterectomies underwent initial HPV DNA testing using the original Hybrid Capture Tube test; a stratified subsample of 1119 specimens was retested using the more analytically sensitive second generation assay, the Hybrid Capture II test.

MAIN OUTCOME MEASURES

Receiver operating characteristic analysis of detection of cervical high-grade intraepithelial lesions and cancer by HPV DNA testing based on different cut points of positivity.

RESULTS

An analytic sensitivity of 1.0 pg/mL using the second generation assay would have permitted detection of 88.4% of 138 high-grade lesions and cancers (all 12 cancers were HPV-positive), with colposcopic referral of 12.3% of women. Papanicolaou testing using atypical squamous cells of undetermined significance as a cut point for referral resulted in 77.7% sensitivity and 94.2% specificity, with 6.9% referred. Specificity of the second generation assay for positivity for high-grade lesions and cancer was 89.0%, with 33.8% of remaining HPV DNA-positive subjects having low-grade or equivocal microscopically evident lesions. The higher detection threshold of 10 pg/mL used with the original assay had a sensitivity of 74.8% and a specificity of 93.4%. Lower levels of detection with the second generation assay (<1 pg/mL) proved clinically nonspecific without gains in diagnostic sensitivity.

CONCLUSIONS

In this study population, a cut point of 1.0 pg/mL using the second generation assay permitted sensitive detection of cervical high-grade lesions and cancer, yielding an apparently optimal trade-off between high sensitivity and reasonable specificity for this test. The test will perform best in settings in which sensitive detection of high-grade lesions and cancer is paramount. Because HPV prevalence varies by population, HPV testing positive predictive value for detection of high-grade lesions and cancer will vary accordingly, with implications for utility relative to other cervical cancer screening methods.

Improved amplification of genital human papillomaviruses

Genital human papillomaviruses (HPVs) are commonly detected from clinical samples by consensus PCR methods. Two commonly used primer systems, the MY09-MY11 (MY09/11) primers and the GP5+-GP6+ (GP5+/6+) primers, amplify a broad spectrum of HPV genotypes, but with various levels of sensitivity among the HPV types. Analysis of the primer-target sequence homology for the MY09/11 primers showed an association between inefficient amplification of HPV types and the number and position of mismatches, despite accommodation of sequence variation by inclusion of degenerate base sites. The MY09/11 primers were redesigned to increase the sensitivity of amplification across the type spectrum by using the same primer binding regions in the L1 open reading frame. Sequence heterogeneity was accommodated by designing multiple primer sequences that were combined into an upstream pool of 5 oligonucleotides (PGMY11) and a downstream pool of 13 oligonucleotides (PGMY09), thereby avoiding use of degenerate bases that yield irreproducible primer syntheses. The performance of the PGMY09-PGMY11 (PGMY09/11) primer system relative to that of the standard MY09/11 system was evaluated with a set of 262 cervicovaginal lavage specimens. There was a 91.5% overall agreement between the two systems (kappa = 0.83; P < 0.001). The PGMY09/11 system appeared to be significantly more sensitive than the MY09/11 system, detecting an additional 20 HPV-positive specimens, for a prevalence of 62.8% versus a prevalence of 55.1% with the MY09/11 system (McNemar's chi(2) = 17.2; P < 0.001). The proportion of multiple infections detected increased with the PGMY09/11 system (40. 0 versus 33.8% of positive infections). HPV types 26, 35, 42, 45, 52, 54, 55, 59, 66, 73, and MM7 were detected at least 25% more often with the PGMY09/11 system. The PGMY09/11 primer system affords an increase in type-specific amplification sensitivity over that of the standard MY09/11 primer system. This new primer system will be useful in assessing the natural history of HPV infections, particularly when the analysis requires HPV typing.

Oral contraceptives as risk factors for cervical adenocarcinomas and squamous cell carcinomas

To assess the hypothesis that oral contraceptives (OCs) increase the risk of cervical adenocarcinomas, we conducted a six-center case-control study of 124 patients with adenocarcinomas, 139 with squamous cell carcinomas, and 307 population controls. Women between the ages of 18 and 69 who were newly diagnosed with cervical adenocarcinomas between 1992 and 1996 were eligible. Healthy female controls and a second case group of incident cervical squamous cell carcinomas were matched to the adenocarcinoma cases. All participants were interviewed regarding OCs, other risk factors for cervical carcinoma, and utilization of cytological screening, and a PCR-based test determined HPV genotype of cervical samples for both case groups and controls. Use of OCs was positively and significantly associated with adenocarcinomas and positively but weakly associated with squamous cell carcinomas. Associations between OCs and invasive adenocarcinomas (n = 91), squamous cell carcinoma in situ (n = 48), and invasive squamous cell carcinomas (n = 91) disappeared after accounting for HPV infection, sexual history, and cytological screening, but a positive association remained between current use of OCs and cervical adenocarcinoma in situ (n = 33). This association persisted after stratification by screening and sexual history and after restriction according to HPV status, but small numbers made it difficult to exclude detection bias, selection bias, or residual confounding by HPV as potential explanations Current OC use was associated with cervical adenocarcinomas in situ, but we saw no other evidence that OCs independently increase the risk of cervical carcinomas.

Structural alterations of transforming growth factor-beta receptor genes in human cervical carcinoma

The development and progression of invasive uterine cervical carcinomas appear to be associated with the progressive loss of sensitivity to transforming growth factor-beta (TGFbeta)-mediated cell cycle arrest. In order to identify possible molecular mechanisms responsible for TGFbeta resistance, we screened the 7 exons of the type II (TbetaR-II) TGFbeta receptor and the 9 exons of the type I (TbetaR-I) TGFbeta receptor genes for mutations in 16 paraffin-embedded primary invasive cervical carcinoma specimens. In one of these carcinomas, we found a novel G-->T transversion in exon 3 of TbetaR-II that introduces a premature stop codon (E142Stop) and presumably results in the synthesis of a truncated soluble exoreceptor. In one tumor, a silent A-->C transversion mutation that may affect mRNA splicing was present in exon 6 of TbetaR-I. In addition, 7 of 16 cases were heterozygous for a G-->A polymorphism in intron 7 of TbetaR-I. Finally, we identified a 9 base pair in-frame germline deletion in exon 1 of TbetaR-I resulting in loss of 3 of 9 sequential alanine residues at the N-terminus in 6 of 16 cases. Analysis of specimens from case-control studies indicated that carriers of this del(GGC)3 TbetaR-I variant allele may be at a increased risk for the development of cervical carcinoma (p=0.22). Furthermore, the response of cells expressing the variant receptor to TGFbeta was diminished. Our results support the notion that diverse alterations in the TGFbeta signaling pathway may play a role in the development of cervical cancer.

Collection devices for human papillomavirus

BACKGROUND

Human papillomavirus (HPV) testing has relied to date on samples collected by experienced health professionals. Self-administered testing devices could allow HPV testing to occur in large-scale epidemiologic studies of primary care screening populations. The purpose of this study is to determine whether a self-collection device for cervicovaginal HPV infection could be developed.

METHODS

A prospective randomized trial of a consecutive sampling of 93 women, 18 years or older, receiving routine cervical cancer screening and colposcopy in the urban gynecologic clinics in Philadelphia, Pennsylvania, were randomized into 2 arms. Women in arm 1 used a self-administered tampon before the physician-directed swabs of the cervix; in arm 2, women underwent the physician-directed swab testing before using the self-administered tampon. The concordance of HPV DNA positivity between sampling methods detected by a Hybrid Capture HPV tube test for both low- and high-risk types of HPV was the main outcome measure.

RESULTS

The concordance rate (ie, women whose cultures were classified as negative on both tests or positive on both tests) for arms 1 and 2 were similar: 78.3% and 80.9%, respectively.

CONCLUSIONS

The tampon was equivalent to the physician-directed swab in HPV detection and suggests its feasibility in long-term primary care studies of screening populations.

Cigarette smoking, alcohol consumption and risk of nasopharyngeal carcinoma in Taiwan

OBJECTIVES

Nasopharyngeal carcinoma (NPC) is rare in most countries but occurs with relatively high frequency among southern Chinese populations throughout the world. A case-control study of NPC was conducted in Taiwan to investigate the importance of active and passive cigarette exposure and alcohol consumption as risk factors for this disease.

METHODS

375 histologically confirmed incident NPC cases (99% response rate) were prospectively identified from two hospitals in Taipei between July 1991 and December 1994 and administered a detailed questionnaire. 327 healthy community controls individually matched to cases on sex, age and residence were selected (88% response rate).

RESULTS

After multivariate adjustment, the odds ratio (OR) and 95% confidence interval (CI) was 1.7 (1.1-2.9 with p = 0.03 for increasing dose-response) for those who smoked for > or = 25 years compared with non-smokers. Passive smoking during childhood or adult life was not associated with an increased risk of disease. Alcohol consumption was not associated with NPC risk. The OR for subjects with > or = 15 grams of ethanol per day compared to non-drinkers was 1.1 (95% CI = 0.7-1.7).

CONCLUSIONS

Our results suggest that long term cigarette smoking is associated with NPC but that low level exposure to cigarette smoke via passive exposure and alcohol consumption are not associated with disease risk.

Cytokine and immunoglobulin concentrations in cervical secretions: reproducibility of the Weck-cel collection instrument and correlates of immune measures

Elucidation of local immune response at the cervix is important for understanding and evaluating STD vaccine approaches currently being proposed. However, no well-validated method exists for the collection of cervical secretions for evaluation of cervical immune response. The purpose of this study was to determine the reproducibility of the Weck-cel sponge used to collect cervical secretions for immunological assessment. Additionally, it was possible to examine correlates of immunity as part of our investigation. Two cervical secretion specimens were collected sequentially from each of 120 women using Weck-cel sponges. Cervical secretions were collected prior to Pap smear sampling to avoid blood contamination. At the laboratory, the duplicate specimens were weighed and tested in replicate wells to determine the concentration of two cytokines (IL-10 and IL-12) and two immunoglobulin isotypes (IgG and IgA). IL-12, total IgG, and total IgA showed a strong correlation between samples from the same woman ranging from 0.78 to 0.84. Kappa coefficients obtained after categorizing assay results ranged from 0.62 to 0.67. Variance components analysis suggested that 69% to 85% of the variance observed was accounted for by between-women variance, with the remaining variability attributed to variation between samples collected from the same woman. IL-10 results were less reproducible than those obtained from the other assays examined, suggesting problems with the assay used to measure this cytokine rather than with the Weck-cel sampling instrument. Various factors were found to significantly correlate with cytokine and immunoglobulin measures at the cervix. Age and reproductive status were associated with all four immune measures; women over 50 years of age and those who were postmenopausal had increased concentrations of IL-10, IL-12, IgG, and IgA. Hemoglobin concentrations were positively correlated with IgG and IL-10 concentrations, but not with IgA or IL-12 concentrations, suggesting local production of IgA and IL-12. The concentration of all immune measures decreased with increasing volume of collection. No significant association was observed between time from collection to freezing of specimens and concentrations of cytokines or immunoglobulins. Overall, our data suggest that measurement of immunological parameters in cervical secretions collected using Weck-cel sponges are reproducible. In addition, various correlates of cytokine and immunoglobulin concentrations were identified.

Epidemiologic determinants of vaginal pH

OBJECTIVES

This study was undertaken to evaluate the relationship between vaginal pH and factors related to cervical cancer.

STUDY DESIGN

In a population-based sample of 9161 women from Guanacaste Province in Costa Rica women were categorized into 2 groups, those with vaginal pH in the reference range (4.0-4.5) and those with elevated vaginal pH (5.0-5.5). Odds ratios were used to estimate the relationship between elevated pH and its potential determinants.

RESULTS

Aging was strongly associated with increasing vaginal pH, starting at around 45 years of age and continuing into old age. Menopause was responsible for an additional 1.7-fold increase in the odds of having an elevated pH (odds ratio 1.7, 95% confidence interval 1.4-2.0). Human papillomavirus infection and cervical intraepithelial neoplasia were not associated with changes in pH.

CONCLUSIONS

Our data indicate that vaginal pH is strongly related to age and to menopausal status and thus could be a marker of age-related hormonal changes. Elevated pH does not appear to be associated with risk of high-grade intraepithelial neoplasia among women infected with human papillomavirus.

Utility of liquid-based cytology for cervical carcinoma screening: results of a population-based study conducted in a region of Costa Rica with a high incidence of cervical carcinoma

BACKGROUND

In a study using a split-sample design, liquid-based cytology (ThinPrep Processor, Cytyc Corporation, Boxborough, MA) was compared with the conventional Papanicolaou (Pap) smear in Guanacaste, Costa Rica. The study provides the first population-based comparison of the ThinPrep screening technology and includes "gold standard" measures of diagnostic accuracy.

METHODS

The population-based study was performed among over 8000 women residing in a Costa Rican province with a high incidence of cervical carcinoma. Conventional smears were prepared and diagnosed in Costa Rica, while the residual material on the sampling device was collected into a liquid preservative and shipped to the U.S., where ThinPrep cytologic slides were prepared and diagnosed. Cytologic diagnoses based on the two techniques, categorized according to the Bethesda System, were compared with a "gold standard" final case diagnosis for each patient, also based on Bethesda terminology, that reflected an integrated interpretation of all available data, including cytology, histology, and cervicography. Results were also compared with the results of HPV DNA detection (Hybrid Capture, Digene Corporation, Silver Spring, MD).

RESULTS

ASCUS was the threshold for colposcopy referral. There were significantly more women referred according to this threshold with the ThinPrep slide (12.7%) than with the conventional smear (6.7%, P<0.001). Compared with the final case diagnosis, referral by ThinPrep slides detected 92.9% of cases with high grade squamous intraepithelial lesions (HSIL) and 100% of carcinoma cases. Smears detected 77.8% of HSIL and 90.9% of carcinomas. Thus, ThinPrep cytology was significantly more sensitive in the detection of HSIL and cancer (McNemar test, P<0.001). Adjudication of cases in which the ThinPrep and smear diagnoses disagreed, using the final case diagnoses and the HPV DNA test results as reference standards, suggested that the ThinPrep method was detecting additional true SIL as opposed to false-positives.

CONCLUSIONS

In a population-based study of high risk women, ThinPrep cytology demonstrated significantly increased sensitivity for detecting HSIL and carcinoma, with a concurrent significant increase in colposcopy referrals.

Soluble interleukin 2 receptor levels and cervical neoplasia: results from a population-based case-control study in Costa Rica

Progression from infection with human papillomavirus (HPV) to cervical cancer in some women is thought to involve a permissive host environment, one in which immune response is mobilized in an inappropriate manner. In a previous study (A. Hildesheim et al., Cancer Epidemiol. Biomark. Prev., 6: 807-813, 1997), increasing levels of soluble interleukin 2 receptor (sIL-2R), a known proxy for general immune activation, was found to be positively associated with increasing levels of cervical neoplasia. We attempted to confirm this finding by conducting a nested case-control study of 478 women within a 10,000-woman population-based cohort in Costa Rica. We selected for the study all of the women diagnosed (at enrollment into the cohort) with: (a) low-grade squamous intraepithelial lesions (LSIL, n = 191); (b) high-grade squamous intraepithelial lesions (HSIL, n = 130); or (c) cancer (n = 37). Controls were 120 cytologically normal, HPV-negative women selected from a random sample of the entire cohort. A questionnaire was administered to participants to elicit information on cervical cancer risk factors. All of the women received a pelvic examination during which cervical cells were collected and used for HPV DNA testing by PCR. Blood samples were also collected. Plasma obtained from the blood samples was tested for sIL-2R levels by ELISA. Results indicated that sIL-2R levels increased with age. Among controls, we observed that 44.3% of women over the age of 50 had high levels of sIL-2R (defined as >735 units/ml) compared with 15.8% of women <30 years of age (P = 0.008). When women with cervical disease (LSIL+) were compared with controls, women in the upper quartile of the sIL-2R distribution had an age-adjusted odds ratio (OR) of 2.1 [95% confidence interval (CI), 1.1-4.1]. Comparing each advancing state of neoplasia with its precursor, we found that women with LSIL had higher sIL-2R levels than controls (OR for upper quartile of sIL-2R, 2.3; 95% CI, 1.1-5.2; comparing LSIL cases with controls); women diagnosed with HSIL were similar to the LSIL group (OR for upper quartile of sIL-2R, 1.1; 95% CI, 0.5-2.4; comparing HSIL cases with LSIL cases); and those with cancer had higher sIL-2R levels than subjects with an HSIL diagnosis (OR for upper quartile of sIL-2R = 1.8; 95% CI, 0.5-7.1; comparing cancer cases with HSIL cases). These data suggest that among our study subjects, sIL-2R levels most likely rise as a response to the events of infection and cancerous invasion, but that sIL-2R levels are unlikely to be predictive of disease progression among women with LSIL.

Risk factors for rapid-onset cervical cancer

OBJECTIVES

The current study was designed to elucidate risk factors associated with the development of cervical cancer during the course of routine Papanicolaou smear screening (rapid-onset cervical cancer).

STUDY DESIGN

Four hundred eighty-three women diagnosed with invasive cervical cancer, representing 73% of all such tumors diagnosed in Connecticut between 1985 and 1990, were studied. Papanicolaou smear screening and risk factor information was obtained by questionnaire and physician record review. Results from human papillomavirus deoxyribonucleic acid testing by polymerase chain reaction of tumor samples were available for 278 study participants. Prediagnostic Papanicolaou smear slides were reviewed for 67% of cases with a screening history. Screening history information, slide review, and questionnaire data were used to classify women as having rapid-onset cervical cancer (n = 43), possible rapid-onset cervical cancer (n = 111), or normal-onset cervical cancer (n = 329).

RESULTS

Compared with normal-onset cases, rapid-onset cases tended to be younger (P =.001) and were more likely to be white (P =.002), diagnosed with adenocarcinomas or adenosquamous carcinomas (P =.001), and diagnosed with early-stage disease (P =.001). Cases diagnosed as possible rapid-onset disease tended to have a profile that was intermediate to that observed for rapid-onset and normal-onset cases. Human papillomavirus deoxyribonucleic acid was detected in 75.2% of cases tested. Compared with women who tested positive for human papillomavirus type 16 or other, those positive for human papillomavirus type 18 had a relative risk for rapid-onset disease of 1.6 (95% confidence interval 0.52-4.9). No significant association was observed between type 18 and possible rapid-onset disease when possible rapid-onset cases were compared with women diagnosed with normal-onset cervical cancer (relative risk 0.67, 95% confidence interval 0.29-1.6). Oral contraceptive use, cigarette smoking, number of pregnancies, and a maternal history of cervical cancer were not significantly associated with rapid-onset disease.

CONCLUSIONS

Results from this study suggest that the risk factors associated with the development of rapid-onset cervical cancer are similar to those for normal-onset disease.

Cervicography screening for cervical cancer among 8460 women in a high-risk population

OBJECTIVE

Cervicography was evaluated as a primary screening method for cervical cancer.

STUDY DESIGN

Cervigrams of 8460 women were taken on enrollment into a population-based study of cervical neoplasia. Cervicography results were compared with a referent diagnosis determined by histologic analysis and 3 cytologic tests, and with the performance of conventional cytologic evaluation.

RESULTS

Cervicography identified all 11 cancers, whereas cytologic testing missed 1. Cervicography yielded sensitivities for detecting high-grade squamous intraepithelial lesions or cancer of 49.3% overall (specificity, 95.0%), 54.6% in women younger than 50 years of age, and 26.9% in women 50 years of age and older. Cytologic testing yielded sensitivities for detecting high-grade squamous intraepithelial lesions or cancer of 77.2% overall (specificity, 94. 2%), 75.5% in women younger than 50 years of age, and 84.6% in women 50 years of age and older.

CONCLUSIONS

Cytologic testing performed better than cervicography for the detection of high-grade squamous intraepithelial lesions. Cervicography performed marginally better than cytologic testing for the detection of invasive cervical cancer. Cervicography is not recommended for postmenopausal women.

Familial and sporadic cases of nasopharyngeal carcinoma in Taiwan

BACKGROUND

Nasopharyngeal carcinoma (NPC) has a striking geographic/ethnic distribution, with especially high rates among southern Chinese. Previous studies have indicated that a family history of NPC is associated with increased risk and noted familial clustering in low-risk populations.

MATERIALS AND METHODS

We investigated differences between sporadic and familial cases of NPC in a case-control study of 375 histologically confirmed NPC cases (99% response rate) and 328 age-, sex-, and geographically-matched controls (88% response rate). All participants answered a detailed risk factor interview and donated blood for EBV and CYP 2E1 testing.

RESULTS

Subjects with a first degree relative with NPC had on odds ratio (OR) of 7.6 (95% confidence interval (CI) = 2.3-25), while those with a family history of any other cancer had only a slightly elevated risk of disease (OR = 1.4; 95% CI = .93-2.2). Of the cases, 25 (6.7%) were familial--having at least one first degree relative with NPC. No significant difference was seen between familial and sporadic cases with respect to sex, age, ethnicity, histology or stage. There was a nonsignificant (p = 0.16) increase in T1N2 tumors among familial cases, suggesting a more aggressive tumor. Family history of other cancers, EBV serologies, or the distribution of the RsaI c2 form of the allele of cytochrome P450 2E1 were also not significantly different between the two groups.

CONCLUSIONS

In conclusion, while genetic factors are likely to play an important role in NPC pathogenesis, our results provide little evidence that a familial form of NPC exists with characteristics notably distinct from sporadic cases.

Human leukocyte antigen class I/II alleles and development of human papillomavirus-related cervical neoplasia: results from a case-control study conducted in the United States

The host immune response to human papillomaviruses (HPVs) is believed to be an important determinant of progression of HPV-associated cervical neoplasia. Human leukocyte antigens (HLAs) are important in the presentation of foreign antigens to the immune system. Previous studies have suggested a possible association between HLA and cervical neoplasia, but the specific alleles found to be associated with disease have varied between studies. To further evaluate this issue, we conducted a nested case-control study within a 24,000-woman cohort study in the United States. A total of 711 women were selected for the study: 141 women diagnosed with high-grade squamous intraepithelial lesions (HSILs) of the cervix; 202 women diagnosed with low-grade SILs (LSILs); 166 women with no history of cervical neoplasia, but evidence of HPV-16 infection; and 202 women with no history of cervical abnormalities and who were HPV negative during follow-up as part of our cohort. Cervicovaginal lavage samples collected from participants were used for HPV testing by L1 consensus primer PCR and the Hybrid Capture tube test methods. DNA extracted from these same lavage samples were used for PCR-based HLA genotyping. Our results suggest a positive association between HLA B7 and HLA DQB1*0302 and disease. A negative association with disease was observed for HLA DRB1*1501-DQB1*0602 and DRB1*13. Associations were strongest when analyses were restricted to HPV-16-positive cases as follows. Compared with women who were cytologically normal and HPV negative, HLA B7 was associated with a 1.5-fold increased risk of HPV/LSIL [95% confidence interval (CI) = 0.95-2.5] and a 2.5-fold increased risk of HSIL (95% CI = 1.2-5.1). HLA DQB1*0302 was associated with a 1.5-fold increased risk of HPV/LSIL (95% CI = 0.94-2.4) and a 1.7-fold increased risk of HSIL (95% CI = 0.84-3.5). HLA DRB1*1501-DQB1*0602 was associated with a decreased risk of HSIL [relative risk (RR) = 0.21; 95% CI = 0.07-0.62]. HLA DRB1*13 was associated with a decreased risk of HPV/LSIL (RR = 0.78; 95% CI = 0.51-1.2) and HSIL (RR = 0.63; 95% CI = 0.30-1.3). Individuals who were either homozygous for DQB1*0302 or carriers of both B7 and DQB1*0302 were found to be at highest risk of disease (RR = 4.5, 95% CI = 1.5-14 for HPV/LSIL; and RR = 9.0, 95% CI = 2.4-34 for HSIL). No synergistic effect was observed for the alleles found to be associated with reduced risk of cervical neoplasia. Our findings support previous studies that have found HLA B7 and DQB1*0302 to be positively associated with cervical neoplasia and are consistent with those that have suggested that DRB1*13 is negatively associated with disease, but do not confirm previous assertions that DRB1*1501-DQB1*0602 increases the risk of cervical disease.

Comparison of PCR- and hybrid capture-based human papillomavirus detection systems using multiple cervical specimen collection strategies

This study compared the performances of three human papillomavirus (HPV) detection tests with specimens collected by three alternative procedures. The HPV tests included the Hybrid Capture Tube test (HCT), the microplate-based Hybrid Capture II test (HC II), and the MY09-MY11 L1 consensus primer PCR-based assay. Initial cervical specimens were collected from study subjects with a broom device, and after Papanicolaou smears were made, residual specimens were placed into PreservCyt (PC), a liquid cytology medium. A second specimen was collected from each subject and placed into Digene Specimen Transport Medium (STM). The device for collection of the second specimen alternated with consecutive subjects between a conical cytology brush and a Dacron swab. At the 1.0-pg/ml cutoff, the results of the HC II agreed well with those of the PCR. Specifically, when PCR data were restricted to the types found by the HC II (HPV types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, and 68), there was greater than 90% agreement between the HC II and PCR results with both STM and PC. At a lower cutoff (0.2 pg/ml), HC II-positive results increased further, especially when the test was applied to the PC specimens. However, false-positive HC II results were more often observed at the 0.2-pg/ml cutoff. HC II yielded the highest HPV positivity with specimens placed into PC, followed by specimens collected with a conical brush and placed into STM and, last, by those collected with a Dacron swab and placed into STM. Our results demonstrate the utility of both the STM and PC specimen collection methods and show good agreement between the HC II and PCR.

Performance of a semiautomated Papanicolaou smear screening system: results of a population-based study conducted in Guanacaste, Costa Rica

BACKGROUND

Automated cytology devices have utility in quality assurance applications, but the effectiveness of these devices in primary screening is unknown.

METHODS

Enrollment smears obtained from 7323 women participating in a population-based study sponsored by the National Cancer Institute were screened manually in Costa Rica and then evaluated independently in the U.S. with the PAPNET system (Neuromedical Systems, Inc., Suffern, NY), a semiautomated, neural network-based device. Smears with abnormal PAPNET images were microscopically rescreened and then diagnosed by a U.S. cytopathologist. ThinPrep slides (Cytyc Corporation, Boxborough, MA), prepared from rinses of the cytologic sampler, and cervigrams (National Testing Laboratories, Fenton, MO) were also evaluated. Women with any abnormal cytologic diagnosis or a positive cervigram were referred for colposcopy with biopsy and definitive therapy if indicated.

RESULTS

Based on the U.S. cytotechnologist's review of the PAPNET images, 1017 (13.9%) of 7323 smears were selected for manual screening, resulting in the selection of 492 (6.7%) possibly abnormal slides for referral to the U.S. pathologist. Ultimately, 312 smears (4.3% of the total) were diagnosed as containing squamous cells of undetermined significance or a more severe abnormality (> or =ASCUS), resulting, hypothetically, in the referral of 66.5% of women with a final diagnosis of a squamous intraepithelial lesion or a more severe abnormality (> or =SIL) and 86.0% of patients with > or =high grade SIL. Conventional microscopic screening performed in Costa Rica resulted in the hypothetical referral of 6.5% of patients with > or =ASCUS for colposcopy, including 69.5% of patients with > or =SIL and 79.8% of those with > or =high grade SIL.

CONCLUSIONS

In this study, PAPNET-assisted cytologic screening accurately identified smears obtained from women with high grade SIL or carcinoma. Determination of the clinical cost-effectiveness of PAPNET-assisted screening in routine practice awaits future study.