The causal role of human papillomavirus infections in cervical cancer has been documented beyond reasonable doubt. The association is present in virtually all cervical cancer cases worldwide. It is the right time for medical societies and public health regulators to consider this evidence and to define its preventive and clinical implications. A comprehensive review of key studies and results is presented.

https://jcp.bmj.com/content/jclinpath/55/4/244.full.pdf

The causal relation between human papillomavirus and cervical cancer

Information on age- and sex-specific prevalence of herpes simplex virus (HSV) types 2 and 1 infections is essential to optimize genital herpes control strategies, which increase in importance because accumulating data indicate that HSV-2 infection may increase acquisition and transmission of human immunodeficiency virus. This review summarizes data from peer-reviewed publications of type-specific HSV seroepidemiologic surveys. HSV-2 prevalence is, in general, highest in Africa and the Americas, lower in western and southern Europe than in northern Europe and North America, and lowest in Asia. HSV-2 and -1 prevalence, overall and by age, varies markedly by country, region within country, and population subgroup. Age-specific HSV-2 prevalence is usually higher in women than men and in populations with higher risk sexual behavior. HSV-2 prevalence has increased in the United States but national data from other countries are unavailable. HSV-1 infection is acquired during childhood and adolescence and is markedly more widespread than HSV-2 infection. Further studies are needed in many geographic areas.

Age-Specific Prevalence of Infection with Herpes Simplex Virus Types 2 and 1: A Global Review

Background Human papillomavirus (HPV) infection is the main cause of invasive cervical cancer, but cofactors may act in conjunction with HPV. We performed a pooled analysis of seven case-control studies to examine the effect of one possible HPV cofactor, herpes simplex virus-2 (HSV-2) infection, in the etiology of invasive cervical cancer. Methods Blood and exfoliated cervical specimens were obtained from 1263 case patients with invasive cervical cancer (1158 with squamous-cell carcinomas and 105 with adeno- or adenosquamous-cell carcinomas) and 1117 age-matched control subjects. Western blot analysis and/or an enzyme-linked immunosorbent assay were used to detect type-specific serum antibodies to HSV-2 and HSV-1, and Chlamydia trachomatis serum antibodies were detected using a micro-immunofluorescence assay. HPV DNA was detected using a polymerase chain reaction assay. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were computed from unconditional logistic regression models. Results Overall, HSV-2 seropositivity was higher among case patients with squamous-cell carcinoma (44.4%, 95% CI = 41.5% to 47.3%) or adeno- or adenosquamous-cell carcinoma (43.8%, 95% CI = 34.2% to 53.5%) than among control subjects (25.6%, 95% CI = 23.0% to 28.2%). Cervical specimens from 1098 (94.8%) squamous-cell carcinoma case patients, 95 (90.5%) adeno- or adenosquamous carcinoma case patients, and 164 (14.7%) control subjects were positive for HPV DNA. Among the HPV DNA-positive women, HSV-2 seropositivity was associated with increased risks of squamous-cell carcinoma (OR = 2.19, 95% CI = 1.41 to 3.40) and adeno- or adenosquamous-cell carcinoma (OR = 3.37, 95% CI = 1.47 to 7.74) after adjustment for potential confounders. A similar association between HSV-2 seropositivity and squamous-cell carcinoma risk was observed after further controlling for markers of sexual behavior (OR = 1.96, 95% CI = 1.24 to 3.09). Among control subjects, HSV-2 seropositivity was associated with markers of sexual behavior, but not with cervical HPV DNA positivity. Conclusion HSV-2 infection may act in conjunction with HPV infection to increase the risk of invasive cervical carcinoma.

Herpes Simplex Virus-2 as a Human Papillomavirus Cofactor in the Etiology of Invasive Cervical Cancer

pReVIously ClAssIfIed by IARC As “CARCInogenIC to humAns (gRoup 1)” And wAs deVeloped by sIx sepARAte woRkIng gRoups: phARmACeutICAls; bIologICAl Agents; ARsenIC, metAls, fIbRes, And dusts; RAdIAtIon; peRsonAl hAbIts And IndooR CombustIons; ChemICAl Agents And RelAted oCCupAtIons. thIs Volume 100f CoVeRs ChemICAl Agents And RelAted oCCupAtIons, speCIfICAlly 4-AmInobIphenyl, benzIdIne, dyes metAbolIzed to benzIdIne, 4,4’-methylenebIs(2-ChloRoAnIlIne), 2-nAphthylAmIne, oRtho-toluIdIne, AuRAmIne And AuRAmIne pRoduCtIon, mAgentA And mAgentA pRoduCtIon, benzo[A]pyRene, CoAl gAsIfICAtIon, oCCupAtIonAl exposuRes duRIng CoAl-tAR dIstIllAtIon, CoAl-tAR pItCh, Coke pRoduCtIon, untReAted oR mIldly tReAted mIneRAl oIls, shAle oIls, soot, As found In oCCupAtIonAl exposuRe of ChImney-sweeps, oCCupAtIonAl exposuRes duRIng AlumInIum pRoduCtIon, AflAtoxIns, benzene, bIs(ChloRomethyl)etheR And ChloRomethyl methyl etheR, 1,3-butAdIene, 2,3,7,8-tetRAChloRodIbenzo-pARA-dIoxIn, 2,3,4,7,8-pentAChloRodIbenzofuRAn, And 3,3’,4,4’,5-pentAChloRobIphenyl, ethylene oxIde, foRmAldehyde, sulfuR mustARd, VInyl ChloRIde, IsopRopyl AlCohol mAnufACtuRe by the stRong-ACId pRoCess, mIsts fRom stRong InoRgAnIC ACIds, oCCupAtIonAl exposuRes duRIng IRon And steel foundIng, oCCupAtIonAl exposuRe As A pAInteR, oCCupAtIonAl exposuRes In the RubbeR mAnufACtuRIng IndustRy. beCAuse the sCope of Volume 100 Is so bRoAd, Its monogRAphs ARe foCused on key InfoRmAtIon. eACh monogRAph pResents A desCRIptIon of A CARCInogenIC Agent And how people ARe exposed, CRItICAl oVeRVIews of the epIdemIologICAl studIes And AnImAl CAnCeR bIoAssAys, And A ConCIse ReVIew of the Agent’s toxICokInetICs, plAusIble meChAnIsms of CARCInogenesIs, And potentIAlly susCeptIble populAtIons, And lIfe-stAges. detAIls of the desIgn And Results of IndIVIduAl epIdemIologICAl studIes And AnImAl CAnCeR bIoAssAys ARe summARIzed In tAbles. shoRt tAbles thAt hIghlIght key Results ARe pRInted In Volume 100, And moRe extensIVe tAbles thAt InClude All studIes AppeAR on the monogRAphs pRogRAmme websIte (http://monogRAphs.IARC.fR). It Is hoped thAt thIs Volume, by CompIlIng the knowledge ACCumulAted thRough seVeRAl deCAdes of CAnCeR ReseARCh, wIll stImulAte CAnCeR pReVentIon ACtIVItIes woRldwIde, And wIll be A VAlued ResouRCe foR futuRe ReseARCh to IdentIfy otheR Agents suspeCted of CAusIng CAnCeR In humAns. D es ig n by A ude la d es m ot s

iArc monogrAphs on the evAluAtion oF cArcinogenic risks to humAns

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

The epidemiology of cervical carcinogenesis.

Case-control studies of cervical intra-epithelial neoplasia grade III (CIN III) and of invasive cervical cancer were carried out in Spain and Colombia to assess the relationship between cervical cancer and 6 common sexually transmitted agents (STAs). The CIN-III studies included 525 cases and 512 controls matched for age and for the place of recruitment; the invasive-cancer studies included 373 histologically confirmed cases of squamous-cell carcinoma and 387 age-stratified controls selected randomly from the populations that generated the cases. Antibodies to Chlamydia trachomatis, Neisseria gonorrhoeae, Treponema pallidum, herpes simplex virus type II (HSV-2) and cytomegalovirus (CMV) were tested in 88% of the women. Cervical scrapes were examined for HPV DNA in 63% of the women using a polymerase-chain-reaction assay (PCR). Among controls, the highest antibody prevalence was to CMV (96.5%), followed by HSV-2 (31.4%) and C. trachomatis (23.3%). For all STAs, the sero-prevalence was markedly higher in Colombia than in Spain both for cases and for controls. After adjustment for the presence of HPV DNA, C. trachomatis was the only STA associated with CIN III in both countries; Spain and Colombia. In both countries, the risk of CIN III increased with increasing of C. trachomatis antibody titers. Among Spanish women, an increase in risk of invasive carcinoma was found for those with antibodies to N. gonorrhoeae; those with antibodies to HSV-2 and those with antibodies to C. trachomatis. These associations were present only in HPV-DNA-negative women. Among HPV-DNA-positive women, none of the STAs considered were associated with cervical neoplasia. Our findings could be interpreted as indicating that past infections with HSV-2, N. gonorrhoeae and C. trachomatis are surrogate markers of HPV, but because HPV DNA may have escaped detection, we cannot exclude that these STAs are also of separate etiological significance.

Sexually transmitted agents and cervical neoplasia in Colombia and Spain.

A case-control study of 525 histologically confirmed cases of cervical intraepithelial neoplasia grade Ill and 51 2 controls was done in Spain and Colombia to assess the role of various risk fadors taking into account the effect of human papillomavirus (HPV). The presence of HPV DNA, assessedby a polymerase chain reaction-based method, was the strongest risk factor identified. In Spain the adjusted odds ratio (OR) and 95% confidence interval (Cl) (numbers in

J. Orfila

Papers

Sexually transmitted agents and cervical neoplasia in Colombia and Spain.

RiskFactorsforCervicallntraepithelial NeoplasiaGrade 111/ Carcinoma in Situ inSpain and Colombia1