Selected class I and class II HLA alleles and haplotypes and risk of high-grade cervical intraepithelial neoplasia.

Human leukocyte antigens (HLAs) present foreign antigens to the immune system and may be important determinants of cervical neoplasia. Previously published associations between HLA and cervical neoplasia exhibit considerable variation in findings. The biomarkers of cervical cancer risk (BCCR) case-control study addressed the role of specific HLA alleles as cofactors in the development of high-grade cervical intraepithelial neoplasia (HG-CIN) based on the most consistent evidence from published literature. Cases (N = 381) were women with histologically-confirmed HG-CIN attending colposcopy clinics and controls (N = 884) were women from outpatient clinics with normal cytological screening smears. Subjects were mainly of French-Canadian descent. Cervical specimens were tested for human papillomavirus (HPV) DNA and HLA genotypes by PGMY L1 consensus primer PCR and a PCR sequence-specific primer method, respectively. Unlike other studies, the DQB1*03 and DRB1*13 allele groups were not associated with risk of HG-CIN. The B7-DRB1*1501-DQB1*0602 haplotype was associated with a 41% overall reduction in HG-CIN risk (odds ratio [OR] = 0.59; 95% confidence interval [CI]: 0.36-0.96), and an 83% reduction in risk of HG-CIN among HPV 16 or HPV 18-positive subjects (OR = 0.17; 95%CI: 0.05-0.54). Paradoxically, however, the same haplotype was associated with HPV 16/18 infection risk among controls (OR = 8.44, 95%CI: 1.12-63.73). In conclusion, the B7-DRB1*1501-DQB1*0602 haplotype was protective against HG-CIN, especially in individuals infected with oncogenic HPV, but the mechanism of the association seems to involve multiple steps in the natural history of HPV and CIN.

Human papillomavirus infection: epidemiology and pathophysiology.

More than 120 different types of the human papillomavirus (HPV) have been isolated; >40 of these types infect the epithelial lining of the anogenital tract and other mucosal areas. In the majority of individuals, HPV infections are transient and asymptomatic with most new infections resolving within 2 years. Epidemiological data from the U.S. National Health and Nutrition Examination Survey determined that the prevalence of HPV infection in a representative sample of women was highest in those aged 20-24 years (44.8%). HPV infection has been firmly established as the primary cause of cervical cancer. It is not clearly understood why HPV infections resolve in certain individuals and result in cervical intraepithelial neoplasias in others, but several factors are thought to play a role; including individual susceptibility, immune status and nutrition, endogenous and exogenous hormones, tobacco smoking, parity, co-infection with other sexually transmitted agents such as HIV, herpes simplex virus type 2 and Chlamydia trachomatis as well as viral characteristics such as HPV type, concomitant infection with other types, viral load, HPV variant and viral integration. Worldwide, pooled data from case-control studies indicated that HPV DNA could be detected in 99.7% of women with histologically confirmed squamous cell cervical cancer compared with 13.4% of control women. Both HPV infection and cervical cancer are associated with a substantial economic burden. Pharmacoeconomic data from the United States indicate that HPV infection and HIV were associated with similar total direct medical costs, and HPV infection was more costly than genital herpes and hepatitis B combined in the 15-25 age group. Furthermore, false-negative pap smears from women with precancerous lesions are among the most frequent reasons for medical malpractice litigation in the United States.

Human papillomavirus DNA versus Papanicolaou screening tests for cervical cancer.

BACKGROUND: To determine whether testing for DNA of oncogenic human papillomaviruses (HPV) is superior to the Papanicolaou (Pap) test for cervical-cancer screening, we conducted a randomized trial comparing the two methods. METHODS: We compared HPV testing, using an assay approved by the Food and Drug Administration, with conventional Pap testing as a screening method to identify high-grade cervical intraepithelial neoplasia in women ages 30 to 69 years in Montreal and St. John's, Canada. Women with abnormal Pap test results or a positive HPV test (at least 1 pg of high-risk HPV DNA per milliliter) underwent colposcopy and biopsy, as did a random sample of women with negative tests. Sensitivity and specificity estimates were corrected for verification bias. RESULTS: A total of 10,154 women were randomly assigned to testing. Both tests were performed on all women in a randomly assigned sequence at the same session. The sensitivity of HPV testing for cervical intraepithelial neoplasia of grade 2 or 3 was 94.6% (95% confidence interval [CI], 84.2 to 100), whereas the sensitivity of Pap testing was 55.4% (95% CI, 33.6 to 77.2; P=0.01). The specificity was 94.1% (95% CI, 93.4 to 94.8) for HPV testing and 96.8% (95% CI, 96.3 to 97.3; P<0.001) for Pap testing. Performance was unaffected by the sequence of the tests. The sensitivity of both tests used together was 100%, and the specificity was 92.5%. Triage procedures for Pap or HPV testing resulted in fewer referrals for colposcopy than did either test alone but were less sensitive. No adverse events were reported. CONCLUSIONS: As compared with Pap testing, HPV testing has greater sensitivity for the detection of cervical intraepithelial neoplasia. (Current Controlled Trials number, ISRCTN57612064 [controlled-trials.com].).

Haptoglobin phenotype and risk of cervical neoplasia: a case-control study.

BACKGROUND: Haptoglobin is an acute-phase glycoprotein that influences host response to infections and tumours. The haptoglobin locus is polymorphic with 2 classes of alleles (Hp(1) and Hp(2)) yielding 3 phenotypes: Hp1-1, Hp2-2, and Hp2-1 with structurally and functionally distinct protein products, suggesting that haptoglobin polymorphism may influence susceptibility to infections and cancers. METHODS: We examined the relation between haptoglobin phenotype and high-grade cervical intraepithelial neoplasia (CIN) in a hospital-based case-control study. Cases (n = 307) were women with biopsy-confirmed CIN-2 or CIN-3. Controls (n = 358) were a random sample of women with normal cytology. The PGMY polymerase chain reaction and reverse line blot methods were used for HPV detection and genotyping. Haptoglobin phenotype was determined by polyacrylamide gel electrophoresis. RESULTS: Among controls, phenotype distribution corresponded to allele frequencies of 0.39 for Hp(1) and 0.61 for Hp(2) with no significant deviation from the Hardy-Weinberg equilibrium (p=0.66). With all women included in the analysis, the Hp1-1 phenotype was associated with increased risk of CIN (OR contrasting Hp1-1 vs. Hp2-2 = 1.0; 95% CI: 0.6-1.5). However, in analyses restricted to HPV-positive participants, the Hp1-1 phenotype was associated with 2.7-fold (95% CI: 1.0-7.2) higher risk of CIN. CONCLUSIONS: If confirmed, these findings indicate an increased risk of CIN among women with the Hp1-1 phenotype.

Insulin-like growth factor-I and risk of high-grade cervical intraepithelial neoplasia.

Insulin-like growth factors (IGF) and their binding proteins (IGFBP) have been implicated in the risk of several epithelial or glandular tumors, including prostate cancer, breast cancer, and colon cancer. Cervical cancer, which is also of epithelial origin, has been shown to overexpress receptors for IGF-I, and plasma levels of IGF-I have been positively associated with cervical cancer precursors in one epidemiologic study. In this case-control study, we investigated plasma levels of IGF-I and IGFBP-3 in relation to the risk of histologically confirmed high-grade cervical intraepithelial neoplasia (HGCIN) and the risk of human papillomavirus (HPV) infection. Included in this analysis were 329 cases and 621 controls recruited from clinics affiliated with two Montréal-area hospital centers. We observed a reduced risk of HGCIN for increasing levels of IGF-I, with an adjusted odds ratio (OR) of 0.40 (95% confidence interval, 0.19-0.87) for the highest quartile relative to the lowest quartile of IGF-I. No association was observed between IGFBP-3 levels and HGCIN. Among controls, IGF-I was associated with a decreased risk of being positive for HPV-16 or HPV-18, with an adjusted odds ratio of 0.20 (95% confidence interval, 0.05-0.87) for the highest quartile relative to the lowest quartile of IGF-I. There was no association observed between IGFBP-3 levels and HPV infection status. IGF-I-mediated effects seemed to predominate among women <30 years of age. In contrast to the previously reported study, our results suggest that levels of IGF-I in young women may be inversely associated with HGCIN, a precursor to cervical cancer.

High grade cervical lesions are caused preferentially by non-European variants of HPVs 16 and 18.

The intratypic variability of HPVs 16 and 18 has been extensively studied and has been used as an important tool in epidemiological studies of viral transmission, persistence and progression to clinically relevant cervical lesions. Infections by non-European variants of HPVs 16 and 18 are associated with an increased risk for the development of high grade squamous intraepithelial lesions (HSIL). Our aim was to correlate the intratypic molecular variability of both HPV types and risk of persistent infection and lesion outcome in a cohort study conducted in Brazil. We characterized molecular variants of HPV types 16 and 18 by sequencing a fragment of the LCR, and of the E6 and L1 genes, for HPV-16 variants only. For both types, European variants composed the most prevalent and diverse group. Persistent infections with HPV-18 were associated with continuous detection of European variants. However, risk for simultaneous detection of HSIL and HPV DNA was higher in women harboring non-European variants of HPV-16. The same trend was observed with HSIL detected during follow-up. Our study confirms the association between non-European variants and risk of cervical neoplasia, and highlights the importance of their geographic distribution for cervical cancer risk assessment.

Associations between serum carotenoids and tocopherols and type-specific HPV persistence: the Ludwig-McGill cohort study.

Although oncogenic HPV infections have been established as the necessary cause of cervical cancer, most HPV infections are transient and rarely progress to cervical lesions. Current research is focused on identifying factors associated with viral persistence and clearance, such as nutritional status. We evaluated the association between serum antioxidant nutrients (retinol, 10 carotenoids and 3 tocopherols) and type-specific HPV persistence over 4 visits among 405 women participating in the Ludwig-McGill cohort study. We measured circulating carotenoids and tocopherol at 4 different clinical visits for each woman. We report the results from different analytic approaches (a case-control approach at both the woman and viral level, and a prospective approach based on persistent events) that examined the association between these micronutrients and type-specific oncogenic and nononcogenic HPV persistence. In the case-control analysis at the viral level, midcirculating levels of alpha-tocopherol were inversely associated with nononcogenic HPV persistent infection (adjusted odds ratio (AOR) = 0.28, 95% CI 0.14-0.57), while high levels were marginally associated (AOR = 0.59, 95% CI 0.28-1.19). Similarly, utilizing generalized estimating equation models, circulating levels of alpha- and delta-tocopherol in the middle or upper tertiles were inversely associated with type-specific nononcogenic HPV persistence (AOR = 0.44, 95% CI 0.19-0.97 and AOR = 0.46, 95% CI 0.19-1.11, respectively). Our study among Brazilian women suggests that serum levels of tocopherols may be protective against nononcogenic HPV persistence. However, we did not find a strong protective effect (as hypothesized) of other serum antioxidant nutrients and type-specific oncogenic HPV persistence measured over 4 clinical visits.

Lack of agreement between cervicography and cytology and the effect of human papillomavirus infection and viral load.

OBJECTIVE: Cohort studies of the natural history of human papillomavirus (HPV) infection and cervical squamous intraepithelial lesions with repeated screening allow the comparison of different macroscopic and microscopic diagnostic methods. MATERIALS AND METHODS: Concurrent visual inspection using cervicography and conventional Pap cytology tests were performed during multiple visits in a cohort of women attending a maternal and child health clinic in São Paulo, Brazil. HPV infection status at the same visits was determined by polymerase chain reaction followed by typing with specific oligonucleotide probing and viral load quantification. Information on reproductive health and hygiene habits was also collected at each visit. RESULTS: Overall agreement between cervicography and cytology was low (kappa = 0.046), which increased only slightly when high oncogenic-risk HPV types (kappa = 0.120) or high viral burden (>100 copies/cell) (kappa = 0.170) was present. Analysis of reproductive health and hygiene habits revealed somewhat different risk factors for cervical lesions detected by these tests. However, presence of oncogenic HPV DNA (odds ratio = 36.0, 95% CI = 16.6-77.8) and high viral burden (odds ratio = 67.34; 95% CI = 27.1-167.0) were strongly associated with lesions detected by cytology but not by cervicography. CONCLUSIONS: Although changes in the cervix (because of age, gravidity, or hormonal effects) may influence the performance of morphology-based screening tests, the lack of agreement and the different degrees of association with HPV infection measures indicate that a visual inspection method such as cervicography may detect different cervical abnormalities relative to cytology.

Human papillomavirus infections with multiple types and risk of cervical neoplasia.

BACKGROUND: Besides an established role for certain human papillomavirus (HPV) genotypes in the etiology of cervical cancer, little is known about the influence of multiple-type HPV infections on cervical lesion risk. We studied the association between multiple HPV types and cervical lesions among 2,462 Brazilian women participating in the Ludwig-McGill study group investigation of the natural history of HPVs and cervical neoplasia. METHODS: Cervical specimens were typed by a PCR protocol. The cohort's repeated-measurement design permitted the assessment of the relation between the cumulative and concurrent number of HPV types and any-grade squamous intraepithelial lesions (SIL) and high-grade SIL (HSIL). RESULT: At individual visits, 1.9% to 3.2% of the women were infected with multiple HPVs. Cumulatively during the first year and the first 4 years of follow-up, 12.3% and 22.3% were infected with multiple types, respectively. HSIL risk markedly increased with the number of types [odds ratio (OR), 41.5; 95% confidence interval (95% CI), 5.3-323.2 for single-type infections; OR, 91.7; 95% CI, 11.6-728.1 for two to three types; and OR, 424.0; 95% CI, 31.8-5651.8 for four to six types, relative to women consistently HPV-negative during the first year of follow-up]. The excess risks for multiple-type infections remained after exclusion of women infected with HPV-16, with high-risk HPV types, or persistent infections, particularly for any-grade SIL. Coinfections involving HPV-16 and HPV-58 seemed particularly prone to increase risk. CONCLUSION: Infections with multiple HPV types seem to act synergistically in cervical carcinogenesis. These findings have implications for the management of cervical lesions and prediction of the outcome of HPV infections.

Randomized controlled trial of human papillomavirus testing versus Pap cytology in the primary screening for cervical cancer precursors: design, methods and preliminary accrual results of the Canadian cervical cancer screening trial (CCCaST).

Since infection with oncogenic human papillomavirus (HPV) has been considered a necessary cause of cervical cancer, tests for oncogenic HPV types have been proposed as adjuncts or replacements to Pap cytology. We designed the Canadian Cervical Cancer Screening Trial (CCCaST) to compare the relative efficacy of HPV DNA testing and Pap cytology in primary screening for cervical cancer and its high-grade precursors. CCCaST randomized women aged 30-69 years in Montreal (Quebec) and in St. John's (Newfoundland) to 1 of 2 screening groups: focus on Pap (conventional) or focus on HPV testing (Hybrid Capture 2). Women in both arms received both tests, but were randomized as to their order, the first test being the index test. Women with an abnormal Pap test or a positive HPV test underwent colposcopy and biopsy, as did a random sample of women with a negative index test. CCCaST enrolled 9,667 women between October 2002 and October 2004. At enrolment, 2.8% had an abnormal Pap test, 6.1% had a positive HPV test and 1.1% were abnormal in both tests. ASC-US was the most frequent cytological abnormality, representing 64% of abnormal Pap results. The frequency of abnormal Pap and HPV results decreased with increasing age and the proportion of HPV-positive results increased with the severity of Pap abnormality. Efficacy analysis will determine if the extra referrals with HPV DNA testing will translate into a relevant increase in high-grade cervical cancer precursor detection. Because of its design, CCCaST will provide sound evidence for formulating cervical cancer screening strategies.

The p53 codon 72 polymorphism and risk of high-grade cervical intraepithelial neoplasia.

BACKGROUND: The Arg/Arg genotype versus Arg/Pro or Pro/Pro at codon 72 of the p53 gene has been implicated in increasing susceptibility of the cervix to human papillomavirus (HPV) infection and thus altering cancer risk. However, research on this topic has been contentious, which prompted us to carry out a case-control study in the Montreal area. METHODS: Cases were women with histologically-confirmed high-grade cervical intraepithelial neoplasia (HGCIN). Controls were women without a history of cervical abnormalities. From each woman, we obtained a cervical specimen for HPV testing and p53 genotyping, and a questionnaire was completed. DNA sequencing was used to minimize genotype misclassification. A subsample of specimens was also genotyped using the TaqMan assay. RESULTS: There were 357 cases and 760 controls recruited between February 2001 and December 2003. The distribution of Arg/Arg, Arg/Pro and Pro/Pro was 55.2, 36.4 and 8.4%, respectively, among cases, and 52.1, 38.7 and 9.2%, among controls, corresponding to an odds ratio (OR) adjusted for ancestral origin of 1.16 (95% confidence interval (CI): 0.9-1.5) for Arg/Arg versus other genotypes. When restricted to high-risk HPV-positive women, the adjusted ORs were 1.40 (CI: 0.9-2.1) and 2.12 (CI: 1.1-4.2), for Arg/Arg versus other genotypes and versus Pro/Pro, respectively. The findings were comparable with analyses of genotype results that agreed between DNA sequencing and TaqMan. CONCLUSIONS: In this study, we attempted to minimize selection bias, population stratification and genotype misclassification. The results suggest that the role of the p53 codon 72 polymorphism on HGCIN is weak at best. Further research may reveal if the polymorphism has a stronger influence on the risk of invasive cervical cancer.

Temporal variation and identification of factors associated with endogenous retinoic acid isomers in serum from Brazilian women.

OBJECTIVE: Retinoids (natural and synthetic derivatives of vitamin A) have cancer chemotherapeutic and chemopreventive activities. Retinoic acid (RA) treatment has been associated with significant regression of preneoplastic lesions. However, serious toxicity associated with some therapies has made long-term chemoprevention in healthy populations unfeasible. Recently, serum RA has been shown to increase in response to oral retinol (vitamin A) supplementation. Here, we assess the variability of circulating RA levels and the lifestyle, demographic, and nutritional factors that explain such variability. METHOD: Total RA concentration and the concentrations of RA isomers (all-trans-RA, 13-cis-RA, and 9-cis-RA) were measured by high-pressure liquid chromatography in serum samples obtained 4 months apart from 502 women participating in the Ludwig-McGill Cohort (Sao Paulo, Brazil). RESULTS: The relative abundance of the three RA isomers was similar for each visit (baseline and month 4), with 13-cis-RA having the highest concentrations followed by 9-cis-RA and all-trans-RA. The within-person variability of total RA and individual isomers was low. Using multivariate logistic regression models (upper tertile versus low/middle tertile of serum RA), we found that age, race, oral contraceptive use, total number of pregnancies, and season of initial blood draw were significantly associated with at least one endogenous RA isomer level. All endogenous RA isomers were positively associated with serum retinol, beta-carotene, and beta-cryptoxanthin levels. CONCLUSION: These results have implications for the design of future epidemiologic studies focused on assessing RA-disease association and intervention studies aimed at modulating RA levels.

Other Gynecologic Cancers: endometrial, ovarian, vulvar and vaginal cancers.

HEALTH ISSUE: In Canada, cancers of the endometrium, ovaries, vulva, vagina, placenta and adnexa account for 11% of all malignant neoplasms in women and 81% of all genital cancers. Although the incidence and mortality from vulvar and vaginal cancers are very low, endometrium and ovarian cancer are important public health problems. KEY FINDINGS: In Canada, there has been no appreciable improvement in survival for women with advanced endometrial (EC) or ovarian cancer (OC) over the past 30 years. The prognosis of EC is good for most patients because diagnosis is made at early stages. However, survival of OC is poor; more than 70% of cases are diagnosed at late stages. Up to 10% of OCs is linked to familial aggregation. Cancers of the vulva and of the vagina are very rare. The survival experience for women with the latter is worse than for those with the former. Both share many risk factors with cervical cancer and the recent developments in the study of HPV infection should be applicable to these diseases as well. Of particular interest will be the advent of vaccines for the primary prevention of HPV infection. DATA GAPS AND RECOMMENDATIONS: At present, the best available means to diagnose gynecologic malignancies is a detailed clinical examination, considering the totality of information on potential and proven risk factors, such as age, reproductive health, sexual practices, use unopposed estrogens or of oral contraceptives or tubal ligation, obesity, diet, smoking, and the familial clustering of some of these cancers.

Cancer of the Uterine Cervix.

HEALTH ISSUE: Cervical cancer is one of the most common malignant diseases of women; it is diagnosed in almost half a million women every year and half as many die from it annually. In Canada and other industrialized countries, its incidence has decreased due to cytology screening. However, invasive cases still occur, particularly among immigrant groups and native Canadian women. Although incidence of squamous cell carcinomas has decreased, the proportion of adenocarcinomas has increased because Pap cytology is ineffective to detect these lesions. KEY FINDINGS: In Canada, cervical cancer will cause an estimated 11,000 person-years of life lost. In most Canadian provinces, early detection is dependent on opportunistic screening. Primary prevention can be achieved through health education (sexual behavior modification) and vaccination to prevent infection from Human Papillomavirus (HPV). The initial results from vaccination trials are encouraging but wide scale use is more than a decade away. DATA GAPS AND RECOMMENDATIONS: Most cases of cervical cancer occur because the Pap smear was either false negative, was not done or not done often enough. Appropriate recommendations and guidelines exist on implementation of cytology-based programs. However, most Canadian women do not have access to organized screening. Further research is needed to 1) evaluate automated cytology systems; 2) define appropriate management of precursor lesions and 3) deliver definitive evidence of HPV testing efficacy in long-term follow-up studies with invasive cancer as an outcome and 4) provide Canadian data to justify augmenting or modifying current programs to use HPV testing in secondary triage of equivocal Pap smears.

Dietary intake and risk of persistent human papillomavirus (HPV) infection: the Ludwig-McGill HPV Natural History Study.

The association between dietary intake and persistence of type-specific human papillomavirus (HPV) infection, during a 12-month period, among 433 women participating in the Ludwig-McGill HPV Natural History Study was evaluated by use of a nested case-control design. Dietary intake was assessed by a food-frequency questionnaire at the month-4 visit. HPV status was assessed at months 0, 4, 8, and 12 by polymerase chain reaction (MY09/11). Only women who ever tested positive for HPV were included in the present study: 248 had transient HPV infections (1 of 4 positive tests or nonconsecutively positive), and 185 had persistent HPV infections (> or =2 consecutive tests positive for the same HPV type). Risk of type-specific, persistent HPV infection was lower among women reporting intake values of beta-cryptoxanthin and lutein/zeaxanthin in the upper 2 quartiles and intake values of vitamin C in the upper quartile, compared with those reporting intake in the lowest quartile. Consumption of papaya > or =1 time/week was inversely associated with persistent HPV infection.