Oncogenic transformation by human papillomavirus type 16 deoxyribonucleic acid in the presence of progesterone or progestins from oral contraceptives

Hormonal Therapy for Gynecological Cancers: How Far Has Science Progressed toward Clinical Applications?

Simple Summary

The most common therapies for severe and recurrent gynecological cancers are hormone therapy and chemotherapy, and responsiveness to therapy is a key component in prognosis and survivability. Hormone therapy has recently been demonstrated to be an excellent cancer treatment approach. Hormone treatment for gynecological cancers is taking drugs that decrease hormone levels or impede their biological activity, halting or slowing cancer progression. Hormone therapy works by suppressing the multiplication of cancer cells triggered by hormones. Hormonal therapy, such as progestogens or tamoxifen, is frequently recommended for patients with hormone-sensitive recurrent or metastatic gynecological cancers, but response rates and therapeutic effects are inconsistent. Therefore, we discuss the pathogenesis of gynecological malignancies from the hormonal landscape and the use of hormonal therapies toward clinical applications.

Abstract

In recent years, hormone therapy has been shown to be a remarkable treatment option for cancer. Hormone treatment for gynecological cancers involves the use of medications that reduce the level of hormones or inhibit their biological activity, thereby stopping or slowing cancer growth. Hormone treatment works by preventing hormones from causing cancer cells to multiply. Aromatase inhibitors, anti-estrogens, progestin, estrogen receptor (ER) antagonists, GnRH agonists, and progestogen are effectively used as therapeutics for vulvar cancer, cervical cancer, vaginal cancer, uterine cancer, and ovarian cancer. Hormone replacement therapy has a high success rate. In particular, progestogen and estrogen replacement are associated with a decreased incidence of gynecological cancers in women infected with human papillomavirus (HPV). The activation of estrogen via the transcriptional functionality of ERα may either be promoted or decreased by gene products of HPV. Hormonal treatment is frequently administered to patients with hormone-sensitive recurring or metastatic gynecologic malignancies, although response rates and therapeutic outcomes are inconsistent. Therefore, this review outlines the use of hormonal therapy for gynecological cancers and identifies the current knowledge gaps.

Hormone-Related Cancer and Autoimmune Diseases: A Complex Interplay to be Discovered

Neoplasic transformation is a continuous process that occurs in the body. Even before clinical signs, the immune system is capable of recognizing these aberrant cells and reacting to suppress them. However, transformed cells acquire the ability to evade innate and adaptive immune defenses through the secretion of molecules that inhibit immune effector functions, resulting in tumor progression. Hormones have the ability to modulate the immune system and are involved in the pathogenesis of autoimmune diseases, and cancer. Hormones can control both the innate and adaptive immune systems in men and women. For example androgens reduce immunity through modulating the production of pro-inflammatory and anti-inflammatory mediators. Women are more prone than men to suffer from autoimmune diseases such as systemic lupus erythematosus, psoriasis and others. This is linked to female hormones modulating the immune system. Patients with autoimmune diseases consistently have an increased risk of cancer, either as a result of underlying immune system dysregulation or as a side effect of pharmaceutical treatments. Epidemiological data on cancer incidence emphasize the link between the immune system and cancer. We outline and illustrate the occurrence of hormone-related cancer and its relationship to the immune system or autoimmune diseases in this review. It is obvious that some observations are contentious and require explanation of molecular mechanisms and validation. As a result, future research should clarify the molecular pathways involved, including any causal relationships, in order to eventually allocate information that will aid in the treatment of hormone-sensitive cancer and autoimmune illness.

Hormone replacement therapy and cervical cancer: a systematic review of the literature

Gynecological tumor treatment, including cervical cancer (CC) treatment, often leads to iatrogenic premature menopause. This highlights the critical importance of investigating indications for hormone replacement therapy (HRT), as most patients, thanks to the improvement in diagnosis and treatment, have to deal with the sequelae of their cancer treatments for many years. This systematic review aims to provide an overview of the current knowledge regarding the risks of HRT and CC. In particular, we aim to investigate whether the use of HRT can increase CC incidence, and evaluate its risk in CC survivors. A systematic review, in agreement with PRISMA guidelines, of the English literature present in PubMed and SCOPUS has been performed. A total of 2805 articles have been screened, of which 10 were considered eligible. Several studies reported a significantly reduced risk of developing cervical squamous cell carcinoma in postmenopausal women treated with HRT, while a weak increase in the incidence of adenocarcinoma has been shown. No evidence reports a harmful effect of HRT on CC oncological outcome, while several benefits, in terms of reduced metabolic risk and increased quality of life, have been described, thus concluding that HRT should be offered to young CC survivors for the management of early menopause.

Role of nuclear progesterone receptor isoforms in uterine pathophysiology

BACKGROUND

Progesterone is a key hormonal regulator of the female reproductive system. It plays a major role to prepare the uterus for implantation and in the establishment and maintenance of pregnancy. Actions of progesterone on the uterine tissues (endometrium, myometrium and cervix) are mediated by the combined effects of two progesterone receptor (PR) isoforms, designated PR-A and PR-B. Both receptors function primarily as ligand-activated transcription factors. Progesterone action on the uterine tissues is qualitatively and quantitatively determined by the relative levels and transcriptional activities of PR-A and PR-B. The transcriptional activity of the PR isoforms is affected by specific transcriptional coregulators and by PR post-translational modifications that affect gene promoter targeting. In this context, appropriate temporal and cell-specific expression and function of PR-A and PR-B are critical for normal uterine function.

METHODS

Relevant studies describing the role of PRs in uterine physiology and pathology (endometriosis, uterine leiomyoma, endometrial cancer, cervical cancer and recurrent pregnancy loss) were comprehensively searched using PubMed, Cochrane Library, Web of Science, and Google Scholar and critically reviewed.

RESULTS

Progesterone, acting through PR-A and PR-B, regulates the development and function of the endometrium and induces changes in cells essential for implantation and the establishment and maintenance of pregnancy. During pregnancy, progesterone via the PRs promotes myometrial relaxation and cervical closure. Withdrawal of PR-mediated progesterone signaling triggers menstruation and parturition. PR-mediated progesterone signaling is anti-mitogenic in endometrial epithelial cells, and as such, mitigates the tropic effects of estrogen on eutopic normal endometrium, and on ectopic implants in endometriosis. Similarly, ligand-activated PRs function as tumor suppressors in endometrial cancer cells through inhibition of key cellular signaling pathways required for growth. In contrast, progesterone via PR activation appears to increase leiomyoma growth. The exact role of PRs in cervical cancer is unclear. PRs regulate implantation and therefore aberrant PR function may be implicated in recurrent pregnancy loss (RPL). PRs likely regulate key immunogenic factors involved in RPL. However, the exact role of PRs in the pathophysiology of RPL and the use of progesterone for therapeutic benefit remains uncertain.

CONCLUSIONS

PRs are key mediators of progesterone action in uterine tissues and are essential for normal uterine function. Aberrant PR function (due to abnormal expression and/or function) is a major cause of uterine pathophysiology. Further investigation of the underlying mechanisms of PR isoform action in the uterus is required, as this knowledge will afford the opportunity to create progestin/PR-based therapeutics to treat various uterine pathologies.

A retrospective study on cervical intraepithelial lesions of low-grade and undetermined significance: evolution, associated factors and cytohistological correlation

CONTEXT AND OBJECTIVES

Cervical cancer is an important cause of morbidity and mortality throughout the world. There is some controversy about the factors that may be associated with infection by the human papillomavirus (HPV) that may favor or protect against evolution from a low-grade intraepithelial lesion to a high-grade intraepithelial lesion or invasive neoplasia. The objective here was to evaluate the evolution of low-grade intraepithelial lesions and squamous or glandular lesions of undetermined significance, the associated factors and cytohistological correlations.

DESIGN AND SETTING

Retrospective study conducted in a public tertiary-level university hospital.

METHODS

Information was obtained by reviewing patient records and/or colposcopy reports. A statistical analysis was performed using logistic regression, calculating the odds ratio and applying chi-square tests.

RESULTS

Of the 3390 patients, 409 evolved to high-grade intraepithelial lesions, of which 354 had an initial diagnosis of HPV infection, 27 of squamous atypia of undetermined significance, 22 of low-grade intraepithelial lesions with or without cytological diagnosis of infection by associated HPV and six of glandular cell atypia of undetermined significance.

CONCLUSIONS

Lactobacillus sp and bacterial vaginosis on the smears, smoking and immunodepression were factors associated with evolution. A single partner, use of hormonal contraceptives, lower parity, age and a cytological diagnosis of cytolytic vaginosis, T. vaginalis, Candida sp or cocci were factors associated with protection. With regard to cytohistological correlation, there was a 74.08% agreement among patients with high-grade lesions and a biopsy obtained during the same period.

Depot-medroxyprogesterone acetate and combined oral contraceptive use and cervical neoplasia among women with oncogenic human papillomavirus infection

OBJECTIVE

The objective of the study was to examine the relationship of depot-medroxyprogesterone acetate (DMPA) and combined oral contraceptive (COC) use with cervical intraepithelial neoplasia (CIN).

STUDY DESIGN

Two case-control studies of women who presented for gynecologic care and underwent cytologic and human papillomavirus (HPV) testing were performed. The first included oncogenic HPV-positive women grouped based on histology: negative (n = 152), CIN1 (n = 133), and CIN2-3 or greater (n = 173). For the second, 2 groups were identified: negative HPV/negative histology (n = 107) and positive oncogenic HPV/negative histology (n = 152).

RESULTS

Among oncogenic HPV-positive women, DMPA use was inversely associated with CIN2-3 or greater (adjusted odds ratio [OR(adj)], 0.4; 95% confidence interval [CI], 0.2-1.1) and CIN1 (OR(adj), 0.1; 95% CI, 0.01-0.6); COC use was not associated with either. Among histologically negative women, DMPA use was associated with oncogenic HPV (OR(adj), 4.7; 95% CI, 1.4-15.8).

CONCLUSION

Among women with oncogenic HPV, hormonal contraceptive use was not associated with an increased risk of CIN2-3 or greater. Longer-term DMPA use may attenuate the colposcopic and histologic features of CIN because women reporting such use were more likely than others to have cervical oncogenic HPV without evidence of CIN.

[Is early first intercourse a risk factor for cervical cancer?]

Sexual behavior has long been known to be a risk factor for cervical carcinoma. Certain sexual risk factors are related to an increased risk of chronic infection of the cervical transformation zone with high-risk human papilloma viruses (HPVs). Numerous retrospective analyses consider early first intercourse a probable risk factor for later development of cervical carcinoma. Since risk factors are associated, it is unclear whether early first intercourse is an independent risk factor for cervical neoplasia. Few comprehensive retrospective studies are available. It is possible that the cervical transformation zone is particularly vulnerable to infection between menarche and the age of sixteen. During this phase there are a large number of undifferentiated cells at the periphery of the metaplasia, practically at the surface of the cervix. It seems that this area is particularly susceptible to HPV infection. There are also indications that there is no secondary immune response to HPV at the time of early first intercourse, making the immune response to HPV less efficient. Other possible risk factors for cervical cancer include genetic predisposition, nutrition, smoking, Chlamydia or HSV-2 infections, drug abuse, oral contraception, immune suppression and early first pregnancy. Education appears important to encourage responsible sexual behaviour in young people.

HPV prevalence and concordance in the cervix and oral cavity of pregnant women

OBJECTIVES

This investigation examined human papillomavirus (HPV) in pregnant women in order to characterize viral prevalence, types and concordance between infection in the cervix and in the oral cavity.

METHODS

A total of 577 pregnant women seeking routine obstetric care were evaluated for HPV infection in their cervix during gestation and immediately before delivery, and in the oral cavity during gestation. Male partners present during the gestational clinic visit also provided a specimen from their oral cavity. HPV assessment was performed by PCR, dot blot hybridization and DNA sequencing. A sexual and health questionnaire was completed by the pregnant women.

RESULTS

HPV prevalence in women was 29% in the cervix and 2.4% in the oral cavity. Among those with both gestational and delivery specimens, 35% were infected at least once and 20% had infection at both intervals. At delivery, 68% of infected women had an oncogenic HPV type in the cervix. There was no type-specific HPV concordance between the two cervical specimens, nor cervical and oral results in women, nor with cervical and oral findings between partners.

CONCLUSION

The lack of association in HPV positivity and types between the cervix and oral cavity in these women suggests that self-inoculation is uncommon. This source of infection does not appear to be from oral contact with a current male partner, since there also was no concordance between partners. These results suggest either other modes of HPV transmission or differences in susceptibility to HPV infection or its clearance in the oral cavity and genital mucosa.

Natural History of Human Papillomavirus Type 16 Virus-Like Particle Antibodies in Young Women

Immunization with a vaccine of human papillomavirus (HPV) type 16 virus-like particles (VLPs) can reduce incidence of HPV-16 infection and its related cervical intraepithelial neoplasia. However, development of detectable antibodies to VLPs does not always occur after natural HPV infection. This study examined prospectively for seroconversion and duration of antibodies to HPV-16 VLPs and their associated host and viral factors. Six-hundred eight subjects were tested for HPV DNA biannually and for IgG and IgA antibodies to HPV-16 VLPs annually for 3 years. Both IgG and IgA antibodies to HPV-16 VLPs were predominantly type specific. Women with cervicovaginal HPV-16 infection were 8-10 times more likely to seroconvert than those with infection of HPV-16-related types. Among subjects who had an incident infection with HPV-16, a maximum of 56.7% became seropositive for IgG within 8.3 months and 37.0% had IgA within 14 months. Detectable seroconversion was a slow process that required sufficient antigenic exposure associated with either a high viral load (relative risk = 5.7 for IgG) or persistent infection of HPV-16 (relative risk = 3.4 for IgA). The median duration for both types of antibodies was approximately 36 months. Antibodies could persist for a long period of time if the initial antibody levels were high or if there was continued antigenic exposure.

The interaction between steroid hormones, human papillomavirus type 16, E6 oncogene expression, and cervical cancer

Various risk factors have been implicated in the causation of cervical cancer including human papillomavirus (HPV), the early genes (E6 and E7 ) of which encode the main transforming proteins. Studies have suggested that steroid hormones may enhance the expression of these genes leading to loss of p53 gene-mediated cell apoptosis. A total of 120 cervical tissue samples were obtained from patients with proven cervical cancer. Patients who used depo-medroxyprogesterone acetate steroid contraception were recruited as part of the steroid arm. Only HPV DNA type 16 samples were used for the study. Controls included three cell lines (CaSki, SiHa, & C33A) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was used as an internal housekeeping gene. Of 120 patients, there were 111 patients with HPV type 16 identified. Of this number, RNA was present in 63 samples. There were 30 women (30/63) who used steroid contraception. In relation to patients who used contraception, HPV 16 E6 gene expression was present in 79% (n = 23) and 88% (n = 30) of steroid users compared to nonusers, respectively. In total there were 25 patients (40%) with expression of the HPV 16 E6*I gene and 30 patients with expression of the E6*II gene. There were 57% of steroid users (n = 17) who had expression of the E6*I/E6*II gene, compared to 52% (n = 17) of nonusers (P = 0.800). From a molecular level, this study does not confirm the role of injectable progesterones in cervical carcinogenesis.

Relationship between steroid hormone contraceptives and HPV, cervical intraepithelial neoplasia and cervical carcinoma

Available data demonstrate an increase in the transcription of high-risk papillomaviruses by the 16alpha-hydroxylation of estrogens, which is in line with the epidemiologic data showing an increased cervical carcinogenesis risk for long-term contraceptive-using, HPV-infected women. No evidence exists for an increase in HPV-negative contraceptive users.

Prevalence and persistence of human papillomavirus in postmenopausal age women

Little is known about the prevalence and persistence of human papillomavirus (HPV) in older women, or about the association between hormone replacement therapy (HRT) use and HPV detection. Like oral contraceptives, HRT hormones may upregulate viral expression and subsequent risk of genital cancer. Postmenopausal women seeking routine gynecologic care were evaluated for HPV infection, testing cervical/vaginal cytology by PCR/DNA sequencing. The prevalence of HPV was 14%; 6% had oncogenic types and 5.8% had persistent infection. Although risk of HPV detection was non-significantly elevated after adjustment for age and HPV-related risk factors among current (adjusted odds ratio (OR)=2.3) and past (adjusted OR=3.2) hormone users compared to never users, past users had a significantly higher risk using combination HRT regimens with increasing duration (adjusted OR=1.8 per year; 95% confidence interval (CI)=1.1-3.1). These findings suggest that a significant percentage of older women are infected with HPV. This may put them at increased risk of genital cancers with longer use of HRTs. Additional studies are needed.

Is use of hormone replacement therapy associated with increased detection of human papillomavirus and potential risk of HPV-related genital cancers?

Oral contraceptives (OC) are a risk factor for female genital cancers and in vivo studies have shown that progestins stimulate human papillomavirus (HPV) gene expression. A similar role for hormone replacement therapy (HRT) has received little evaluation. Cervical/vaginal specimens were obtained to detect HPV from postmenopausal women (n = 429) seeking annual gynaecologic care. HPV was detected in 14% of women and 4.4% had high-risk, oncogenic types. HPV prevalence was similar across current, past and never HRT users. After adjustment for HPV-related risk factors, current and past user status showed no increased viral detection compared with never users. HRT duration also did not elevate risk among current users. However, longer duration (adj. OR 1.5/year, 95% CI 1.0-2.3) and longer latency (adj. OR 1.2/year, 95% CI 0.9-1.7) among past users of oestrogen/progestin regimens were associated with greater risk. Overall use of HRTs was not associated with HPV detection or disease. However, past users of combination HRTs had significantly greater risk of HPV detection with longer HRT duration and latency, similar to OC-HPV findings. The recommendation that postmenopausal women continue HRTs long term may lead to an increased development of HPV-related diseases, of particular concern among those who discontinue HRTs and subsequent gynaecologic care for early cancer detection.

The role of human papillomavirus in cervical adenocarcinoma carcinogenesis

Human papillomavirus (HPV) is considered the single most important co-factor in the development of cervical squamous cell carcinomas. Adenocarcinomas of the cervix are also related to HPV, but the correlation is reported to be less pronounced. In the present study, 131 cervical adenocarcinomas were identified through the Swedish Cancer Registry, examined morphologically and then analysed with sensitive polymerase chain reaction (PCR)-based HPV methods for a study of age-related prevalence of HPV. HPV was identified in 64% of the tumours after PCR amplification of the HPV L1 gene only and in 71% following PCR amplification of both the L1 and E6 genes of HPV. HPV 18 was the most prevalent (52%), followed by HPV 16 (33%) and other types of HPV (15%). The prevalence of HPV was shown to be age-dependent. In women younger than 40 years, HPV was present in 89%, whereas in women 60 years and older, HPV was observed in only 43%. The difference was statistically significant, P<0.005. The HPV-positive adenocarcinomas were represented by an age distribution similar to that of cervical squamous carcinomas with a maximum age, in the 40-49 year old group, whereas the frequency of HPV-negative adenocarcinomas increased with age, typical of most carcinomas occurring in elderly women.

Oestrogen and progesterone increase the levels of apoptosis induced by the human papillomavirus type 16 E2 and E7 proteins

Human papillomavirus (HPV) type 16 infects the genital tract and is generally acknowledged to be a causative agent of cervical cancer. HPV infection alone is not sufficient to induce cervical cancer and other factors such as steroid hormones are thought to play a role in the establishment and/or progression of this disease. The HPV-16 E2 protein is required for virus replication and modulates viral gene expression whereas the HPV-16 E7 protein is required for cell transformation. We and others have shown that both the E2 and E7 proteins can induce apoptotic cell death in HPV-transformed and non-HPV transformed cell lines. Here we show that the steroid hormones oestrogen and progesterone can both increase the levels of E2- and E7-induced apoptosis. The oestrogen metabolite 16 alpha-hydroxyoestrone also increases E2- and E7-induced cell death and the dietary component indole-3-carbinol, which reduces the formation of 16alpha-hydroxyoestrone from oestrogen, blocks the effects of oestrogen. Thus the metabolism of oestrogen to 16 alpha-hydroxyoestrone appears to be required for the effects of this hormone on E2- and E7-induced cell death. We also show that the oestrogen receptor antagonist 3-hydroxytamoxifen blocks the effects of oestrogen on E2- and E7-induced cell death, whereas the anti-progesterone RU486 blocks the effects of both progesterone and oestrogen. We discuss these results in terms of the origin and progression of cervical cancer.

Contraceptive and reproductive risk factors for cervical intraepithelial neoplasia in American Indian women

OBJECTIVES

To evaluate contraceptive and reproductive risk factors for cervical intraepithelial neoplasia (CIN) in southwestern American Indian women.

METHODS

We conducted a clinic-based case-control study. Cases were American Indian women with biopsy-proven CIN I, CIN II or CIN III. Controls were from the same clinics and had normal cervical epithelium. All subjects underwent structured interviews focused on contraceptive and reproductive factors. Laboratory assays included polymerase chain reaction (PCR)-based tests for cervical human papillomavirus (HPV) infection.

RESULTS

We enrolled 628 women in the study. The strongest risk factors for CIN II/III included HPV infection (adjusted odds ratio [OR] = 7.9, 95% CI : 4.7-13.2), and low income (OR = 3.1, 95% CI : 1.7-5.7). The use of an intrauterine device (IUD) ever (OR = 3.0, 95% CI : 1.4-6.1) and currently (OR = 4.1, 95% CI : 1.1-14.6), and > or = 3 vaginal deliveries (OR = 5.2, 95% CI : 2.4-11.1) were associated with CIN II/III. History of infertility was also associated with CIN II/III (OR = 2.1, 95% CI : 1.0-4.2).

CONCLUSIONS

The data suggest that history of infertility, IUD use and vaginal deliveries were associated with CIN among American Indian women.

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.

Influence of ovarian stimulation on the detection of human papillomavirus DNA in cervical scrapes obtained from patients undergoing assisted reproductive techniques

OBJECTIVE

To determine whether gonadotropin stimulation influences the detection of human papillomavirus (HPV) DNA in cervical scrapes.

DESIGN

Prospective, controlled study.

SETTING

Tertiary care infertility clinic.

PATIENT(S)

Two hundred ninety-four patients enrolled in an IVF or IUI program. Two thousand two hundred sixty-two women from an ongoing screening study who were of similar age served as a control group.

INTERVENTION(S)

Cervical scrapes were obtained with a cytobrush before and after ovarian stimulation with gonadotropins.

MAIN OUTCOME MEASURE(S)

Human papillomavirus status was assessed with a general primer (GP) polymerase chain reaction (PCR) using the GP5+/GP6+ system. In GP-PCR-positive samples, high-risk HPV types were identified with a cocktail of digoxigenin-labeled oligonucleotides. Viral load was evaluated by semiquantitative analysis of the PCR products.

RESULT(S)

The prevalence of high-risk HPVs was 7.8% before stimulation and 6.8% after stimulation and, thus, was similar to the prevalence in controls (8.4%). Twenty-nine patients were positive for high-risk HPVs: 14 were positive before and after stimulation, 6 were negative before and positive after stimulation, and 9 were positive before and negative after stimulation. Positivity for high-risk HPVs and viral load did not correlate directly with serum estrogen levels.

CONCLUSION(S)

Ovarian stimulation has no significant effect on the prevalence of HPV DNA in cervical scrapes obtained from patients undergoing assisted reproductive techniques.

Human papillomavirus 16 in breast cancer of women treated for high grade cervical intraepithelial neoplasia (CIN III)

Women with both a history of high grade cervical intraepithelial neoplasia (CIN III) and breast carcinoma as second primary cancer were selected for studying the presence of HPV in breast carcinomas. Paraffin embedded material from 38 patients with 41 breast carcinoma cases after CIN III were examined by polymerase chain reaction (PCR) and in situ hybridization. By PCR we detected HPV 16 DNA in 19 out of 41 cases (46%) of the breast carcinomas. One case proved to be HPV 16 positive also by in situ hybridization. HPV 16 was also detected in 32 out of the 38 patients with CIN III (84%). All HPV 16 positive breast carcinomas were HPV 16 positive in their corresponding CIN III lesions. Eight patients with diagnosed breast cancer before the CIN III lesions were used as controls. None of these had HPV positive breast carcinomas. No cases were positive for HPV 11, 18, or 33. HPV 16 was detected in the primary tumours, in local metastases from HPV 16 positive tumours, in a distant HPV 16 positive breast carcinoma metastasis to the colon, and in other primary cancers in patients with HPV 16 positive breast carcinomas and HPV 16 positive CIN III. Estrogen and progesterone receptors were quantified in the HPV positive and HPV negative breast carcinomas, and there was no significant difference in the fraction positive in the two groups. Oncogenic HPV DNA might be transported from an original site of infection to other organs by blood or lymph, and possibly be a factor in the development of cancer in different organs.

Time since last use of oral contraceptives and risk of invasive cervical cancer

The time-risk relationship for the association between cervical cancer and oral contraceptives (OC) was examined using data on 592 cases of invasive cervical cancer aged 60 years or less and 616 controls with acute, non-gynaecological, non-hormone-related, non-neoplastic diseases. A total of 125 cases and 114 controls reported ever using OC and the multivariate odds ratio (OR) for ever versus never users was 1.21 (95% confidence interval (CI) 0.82-1.74). The risk of invasive cervical cancer was above unity in current users (OR 1.23) and in women who had stopped OC use less than 10 years before diagnosis, but not in those who had stopped their OC use > or = 10 years before (OR 0.85). Similarly, the OR was less for women who had started OC use 15 years or more previously than for more recent users. These data suggest that OCs may have a late stage (promoter) effect on cervical carcinogenesis and thus have public health implications, since the incidence of invasive cervical cancers is low at young ages, when OC use is more common and increases during middle age. The absence of a persisting risk is therefore of interest both for assessing individual risk and for its public health implications.

Influence of ovarian hormones on urogenital infection

Numerous studies have examined the influence of hormones on infectious diseases and there is now a wealth of data relating to the more specific effect of the sex hormones, oestrogen and progesterone, on urogenital infections. The interaction between these hormones and the immune system is complex and the variation of hormonal effect between species further complicates the true picture as related to humans. Although it is difficult therefore to draw general conclusions regarding predominant effects of specific hormones, there is the suggestion that oestrogen enhances the pathogenicity of many urogenital micro-organisms. Our understanding of the influential role played by sex hormones in disease pathogenesis is at an early stage and illustrates well the importance of drawing together and interpreting as a whole both epidemiological and molecular studies.

Is breast cancer caused by late exposure to a common virus?

Although there are recognized risk factors for breast cancer, its cause is still unknown. It is hypothesized here that breast cancer results from late exposure to a common virus. This hypothesis is investigated by relating the epidemiology of breast cancer to the seroepidemiology of cytomegalovirus, as a surrogate for a breast cancer virus. The hypothesis is consistent with the geographical distribution of breast cancer; a correlation between breast cancer incidence and the percentage of adults who are cytomegalovirus seropositive in various countries was found (Pearson correlation coefficient -0.79). The hypothesis is also consistent with other risk factors for breast cancer, such as age at onset, family history, hormonal factors and migration.

The frequency of human papillomavirus detection in postmenopausal women on hormone replacement therapy

Postmenopausal women enrolled in the Iowa portion of the postmenopausal estrogen/progestin interventions randomized clinical trial (n = 105) during 1989-1991 were studied for (i) the prevalence of human papillomavirus (HPV) in this older age population (ages 45-64), and (ii) the association between hormone replacement therapies (HRTs) and changes in detection of HPV over a 2-year time period. HPV is causative in most cervical and some other genital cancers and in the presence of steroid hormones has been shown to increase neoplastic transformation by HPV in vitro. Using PCR to detect HPV DNA, the overall frequency of the virus regardless of time period was 50.3% (n = 53) with a baseline (BL) frequency of 38.1% and the second year follow-up (FU) of 22.9%. The oncogenic types HPV-16 (75.5%) and HPV-31 (20.8%) were the most commonly reported. All those with persistently detected infection (10.5%), defined as HPV+ at both BL and FU, were identified with HPV-16 or -18. Between these two time periods there were no significant differences in HPV frequency between the placebo and combined HRT groups (BL-/FU+, 21% vs 18%; BL+/FU-, 71% vs 80%). While the study is based on a small sample, the findings suggest that short-term use of HRTs is not associated with an increased risk of HPV detection, but assessment of effects from long-term use is needed. The data also indicate that the frequency of HPV found in older women is higher than previously suspected but that short-term changes in HPV detected in this age group are unrelated to the development of precancerous cervical lesions.

Effect of glucocorticoid hormones on viral gene expression, growth, and dysplastic differentiation in HPV16-immortalized ectocervical cells

Steroid hormones are proposed to act as cofactors with human papillomaviruses (HPVs) in the etiology of cervical cancer. We and others reported that progesterone and glucocorticoid hormones induce the expression of HPV16 via three glucocorticoid response elements (GREs) in the viral regulatory region. Consensus GREs (GREcs) are useful in other systems for examining the effect of hormones after enhancing the response with mutated GREc constructs. Therefore, this study used human ectocervical cells (HEC) and HPV type 16 containing three GREcs to establish immortalized cells (HEC-16GREc). Northern blot assays showed that the level of viral E6-E7 oncogene RNA was increased by hormones substantially more in HEC-16GREc than in wild-type HPV16-immortalized human ectocervical cells (HEC-16). The saturation density and the hormone response of the growth rate were significantly higher for HEC-16GREc and the doubling was faster in the presence of hormone than for HEC-16. Although both were nontumorigenic, only HEC-16GREc showed anchorage-independent growth, which was dependent on hormone. Also, HEC-16GREc were more abnormal in their epithelium differentiation pattern in organotypic (raft) cultures. Furthermore, hormone-treated HEC-16GREc rafts showed more dysplastic features than hormone-treated HEC-16 rafts. These results suggest new features of the role of hormones: that enhanced expression of viral oncogenes in response to hormones apparently confers a greater risk for cervical cells containing HPV16. Further, HEC-16GREc could be ideal for studying hormone-dependent and -independent malignant transformation.

Human papillomaviruses and cervical cancer

Molecular and epidemiological studies conducted over the last 20 years led to the recognition of certain types of human papillomavirus (HPV) as the etiological agents of cervical cancer, a very common neoplasia, particularly in developing countries. More than 70 HPVs have been described, including both cutaneous and mucosal types. About half of the known HPVs, and an even higher number of variants, have been isolated from genital mucosas. The association of certain types primarily with normal tissues and benign lesions, as opposed to cancer-associated types, has led to the concept of low and high oncogenic risk HPVs, respectively. The latter express oncogenic proteins that interfere with cell growth control functions. As a consequence of the continuous expression of these viral genomes, chromosome instability may occur, leading to fully transformed cells. Studies indicate that persistence of high-risk HPVs may determine progression to more severe stages of cervical disease, while the majority of HPV infections are transient and do not seem to be important in cervical carcinogenesis. The risk for disease progression seems also to be associated with viral burden. Prospective epidemiological studies will contribute to the knowledge of the natural history of HPV infections and provide information on the determinants of viral persistence. Data derived from these studies may define the clinical utility of HPV testing and its use in cervical cancer prevention programs.

The genetic program of genital human papillomaviruses in infection and cancer

Human papillomavirus (HPV) infection has been recognized as the major cause of cervical cancer. This article summarizes the functions of HPV gene products that cause abnormal cell growth--E6 and E7--and reviews how cellular and viral factors influence their synthesis. E6 and E7 inactivate two cellular tumor-suppressor gene products, p53 and RB. In cervical cancer, E6-E7 gene control is deranged by mutations in viral control sequences and in integrated HPV fragments by the disruption of the viral repressor E2. Elimination of this sequence makes E6-E7 mRNAs unstable, and deranges cellular regulation at the integration site. It is apparent that an intricate interplay of cellular and viral factors determines whether the outcome is active papillomavirus infection, viral latency, or ultimately, genital cancer.

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

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

The epidemiology of cervical carcinogenesis

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

Human papillomaviruses, cervical cancer and the developing world

Carcinoma of the uterine cervix is the commonest cancer of women in the majority of developing countries; in developed countries it is much less common, as well as being less frequent than some other cancers, such as those of breast, lung and colon. The discovery of human papillomavirus (HPV) as an aetiological agent of cervical cancer (and of other anogenital malignancies) has prompted a great deal of interest in the biology and oncogenicity of this virus, including large-scale epidemiological surveys comparing the prevalence of HPV and other possible causative agents between areas of high and low incidence of cervical carcinoma. These studies have thrown up tantalizing clues concerning the virus' pathogenesis and disease associations. Sexual practices, parity, diet, smoking, other diseases (including sexually transmissible diseases) and immunogenetic characteristics may all play a contributory role in the development of cervical carcinoma. These factors may be independent of each other and of association with HPV infection. Immunization to prevent papillomavirus infection and thus cervical cancer is an attractive prospect. Although the potential in using such an approach has been demonstrated in several animal models, there are several major theoretical problems to solve before HPV vaccination becomes a practicality. Intervention to prevent exposure to other aetiological factors and to improve screening may be a more practicable strategy for reducing the burden of cervical cancer.

Human papillomaviruses (HPV) in gynaecological cytology: from molecular biology to clinical testing

Molecular epidemiological and pathological studies show that different HPV types are associated with different cervical lesions allowing classification of the viruses into types associated with 'high', 'intermediate' and 'low' risk of cervical neoplasia. However, HPV infection often regresses and, where it is associated with neoplasia, is an early event. This suggests that other factors are involved in the carcinogenic process, and there is some mechanistic basis for the interaction of epidemiologically defined factors with HPV infection in the process of cervical carcinogenesis. With the refinement of techniques for HPV detection in clinical material, HPV testing is now a realistic possibility, but how this should be performed and in what clinical situation(s) is still uncertain. Particular areas of interest are: (i) the assessment of patients with borderline cytological changes or mild dyskaryosis; and (ii) the definition of those patients at greater risk of invasive disease. Clinical trials are needed before the utility of HPV testing can be properly assessed.

Epidemiology of cervical intraepithelial neoplasia: the role of human papillomavirus

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

Efficacy trial of topically administered interferon gamma-1 beta gel in comparison to laser treatment in cervical intraepithelial neoplasia

OBJECTIVE

Dose dependent response of cervical intraepithelial neoplasia (CIN) to topically administered interferon (IFN) gamma was assessed and compared with conventional laser therapy.

PATIENT AND METHODS

33 women were included in a randomized phase II trial which was double blinded for IFN dosages. Twenty-four patients received IFN gamma-1 beta gel and a control group of nine patients was treated with laser surgery. 18 patients had smears suggesting CIN II and 15 patients had smears suggesting CIN III. The response was assessed 6 months after starting of IFN gamma-1 beta treatment or having laser surgery.

RESULTS

Topical IFN gamma-1 beta treatment gave a cure rate of 42% independent of IFN dosage as compared to an 89% cure rate with laser therapy (P = 0.02). Patients with CIN II responded better compared with patients with CIN III. Current smokers showed a significantly lower cure rate whereas use of oral contraceptives (OC) did not influence response. High viral load with high risk types of human papillomaviruses (HPV) was associated with a better response.

The detection of HPV DNA, the size of tampon specimens and the menstrual cycle

OBJECTIVE

To determine if HPV detection or the size of a tampon specimen is affected by the menstrual cycle.

MATERIALS

Two hundred and eighty women between 18-35 years of age attending a gynaecology clinic at The Royal Women's Hospital were enrolled. Each woman completed a questionnaire on the risk factors of HPV infection and provided a tampon specimen. Specimens were analysed for the presence of HPV DNA (polymerase chain reaction with the L1 consensus primers) after the pellet volume and number of cells was assessed.

RESULTS

The mean age of the 298 women enrolled in this study was 27.0 years (SD 4.5, range 18-35). Ninety two (30.9%) of the tampon specimens were positive for HPV using the L1 consensus primer. The detection of HPV DNA was not associated with the quartiles of the menstrual cycle (p = 0.32). Both the pellet volume and the number of cells from a tampon specimen were greater during the mid cycle, although this was significant for the pellet volume only (p = 0.002 and 0.1 respectively). The pellet volume was not significantly associated with other variables assessed by the questionnaire. The number of cells from a tampon specimen increased with the numbers of life time sexual partners (p = 0.02) and was higher for a single marital status (p = 0.0008).

CONCLUSION

The timing of the menstrual cycle effects the size of tampon specimens but not the probability of detecting HPV DNA.

Quantification of HPV-16 E6-E7 transcription in cervical intraepithelial neoplasia by reverse transcriptase polymerase chain reaction

Human papillomavirus type 16 (HPV-16) is associated with neoplastic lesions of the uterine cervix. Viral transforming functions have been localized to the E6-E7 open reading frame (ORF) and this ORF is conserved consistently in cervical intraepithelial neoplasia (CIN). Two mRNAs, generated by alternative splicing, are expressed from the E6-E7 ORF. These are known as E6*I and E6*II, and potentially encode the viral E7 and E6 proteins, respectively. It is believed that the HPV-16 transforming ability is mediated by the E6 and E7 proteins. A quantitative RT-PCR assay, developed by us to characterize the relative expression of E6-E7 spliced transcripts, was applied to exfoliated cervical cells obtained from patients in varying stages of clinically defined CIN and who were infected with HPV-16. The relationship between viral expression, disease stage, oral contraceptive use and age was studied. No association was observed between age or oral contraceptive use and HPV-16 E6-E7 expression. However, when both E6*I and E6*II were detected, a direct correlation was observed between relative proportions of E6*I/E6*II mRNAs greater than 95%/5% and increased disease severity. This study underscores the importance of the relationship between quantities of viral transforming gene transcript and the course of cervical disease. It also suggests that quantification of HPV-16 E6-E7 transcription may be useful as a prognostic tool to identify women who are at increased risk of developing cervical cancer.

Multiple human papillomavirus type 16 glucocorticoid response elements functional for transformation, transient expression, and DNA-protein interactions

We have previously shown that human papillomavirus type 16 (HPV-16) can efficiently transform primary baby rat kidney cells in the presence of the steroid hormones progesterone and the glucocorticoid dexamethasone. To study this effect of hormone, different combinations of the previously identified glucocorticoid response element (GRE) at nucleotide 7640 of HPV-16 and the other two GREs that we have recently identified, at nucleotides 7385 and 7474, were mutated. The previously described GRE and the other two GREs were shown to be functional for the induction of transformation by dexamethasone. In addition, transient assays in cervical HeLa cells demonstrated the functional importance of the three individual GREs. Assays for in vitro interaction demonstrated the specific binding of a 97-kDa protein, the glucocorticoid receptor, to both recently identified HPV-16 GREs.

Pathogenesis of genital HPV infection

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

Risk factors for cervical cancer in Colombia and Spain

A population-based case-control study of cervical cancer was conducted in Spain and Colombia to assess the relationship between cervical cancer and exposure to human papillomavirus (HPV), selected aspects of sexual and reproductive behaviour, use of oral contraceptives, screening practices and smoking. The study included 436 cases of histologically confirmed squamous-cell carcinoma and 387 age-stratified controls randomly selected from the general population that generated the cases. The presence of HPV DNA in cervical scrapes was assessed by PCR-based methods and was the strongest risk factor (OR = 23.8; 13.4-42.0). Risk estimates for any other factor were only slightly modified after adjusting for HPV status. Among women found positive for HPV DNA, only the use of oral contraceptives was a risk factor for cervical cancer (OR = 6.5; 1.3-31.4 for ever vs. never use). Patients with cervical cancer who were HPV DNA-negative retained most of the established epidemiological features of this disease. This suggests that some instances of HPV infection went undetected or that other sexually transmitted factor(s) contribute to the causation of cervical cancer. Early age at first intercourse (OR = 4.3; 2.1-9.0 for age < 16 vs. 24+) and early age at first birth (OR = 5.0; 1.8-14.2 for age < 16 vs. 24+) were associated with increased risk of cervical cancer; these effects were independent of one another. Low educational level was a risk factor (OR = 2.5; 1.6-3.9). Number of sexual partners was in our study a surrogate for HPV infection. Smoking and parity after age 24 were weakly and inconsistently associated with the risk of cervical cancer. Previous screening (OR = 0.7; 0.5-1.0) and ever having undergone a Caesarean section (OR = 0.4; 0.2-0.8) were protective factors.

Noncontraceptive benefits of modern low-dose oral contraceptives

Most oral contraceptive formulations in current use contain 50 micrograms or less of ethinyl estradiol and 1 mg or less of the various progestins: norethindrone (0.5-1 mg), norgestrel (0.3-0.5 mg), or levonorgestrel (0.05-0.25 mg) [1]. The new generation of progestins--norgestimate, desogestrel and gestodene--are derived from levonorgestrel, the biologically active enantiomer of norgestrel. These steroids have specific metabolic and pharmacologic activity that allow oral contraception at lower doses than previous progestins. Desogestrel and norgestimate are both prodrugs and must undergo hepatic and gastrointestinal metabolism to become biologically active compounds. Gestodene is immediately and completely bioavailable [2]. For the new formulations containing less than 50 micrograms of ethinyl estradiol, the incidence of complications has decreased. With most of the early medical problems identified, current research can now focus on other aspects of oral contraception such as compliance and OC use failure. Prominent noncontraceptive health benefits have been observed in OC users and represent new directions for future research. When the risk-benefit ratio of OC use is evaluated in healthy women today, it clearly favors the benefits. However, these will not be fully realized without an increase in method compliance.

Oral contraceptives and human papillomavirus infection in cervical intraepithelial neoplasia

We report about 142 patients from whom colposcopically directed cervical punch biopsies were taken which showed condylomatous lesions with or without cervical intraepithelial neoplasia (CIN). Fifty-six (39.4%) of these women used oral contraceptives (OC) for at least two years before examination. We used DNA in situ hybridization on all biopsies for detection of human papillomavirus (HPV)-DNA. Among OC users a significant trend towards higher HPV infection rates in high grade CIN (odds ratio 2.9, P less than 0.05) was found, whereas non-users of oral contraceptives had the highest HPV infection rate in condylomatous lesions without CIN (odds ratio 0.5, P less than 0.05). Thus in OC users HPV infection was about 24 times more likely in CIN III as in condyloma, while among non-users the trend was the other way round (7-fold likelihood of HPV positivity in condyloma compared to CIN III). Other known risk factors for cervical carcinoma did not influence HPV infection rates in either group.

Mutations in the ras protooncogenes are rare events in renal cell cancer

Mutations in codon 12, 13 or 61 of one of the three ras genes, Ha-ras, Ki-ras, and N-ras, convert these genes into active oncogenes. To determine the role mutated ras genes play in the carcinogenesis of renal cell carcinoma, we analysed tumour DNA and unaffected renal tissue derived from 55 patients. The polymerase chain reaction technique was used to amplify DNA fragments containing Ki-, Ha-, and N-ras codons 12, 13, and 61. The amplified fragments were then probed on slot-blots with labeled mutation-specific oligomers. A single Ki-ras mutation (codon 12, gly- greater than val) was detected in a patient with a pT2N2M1 tumour. We concluded that ras oncogene mutations do not play an important role in the initiation of renal cell carcinoma.

The interaction between HPV infection and estrogen metabolism in cervical carcinogenesis

Cancer of the genital tract is the final outcome of some infections with human papillomavirus (HPVs), and the most estrogen-sensitive cells are at greatest risk for the HPV-related cancers. Therefore we investigated relationships between HPVs and estrogen metabolism in cells of the genital tract. Increased conversion of estradiol to 16 alpha-hydroxyestrone, known to be a risk factor for cancer in some other estrogen-sensitive cells, was investigated in keratinocytes from the genital tract. Primary cells, particularly those explants from the transformation zone of the cervix, are able to 16 alpha-hydroxylate estradiol. Both cervical and foreskin cells immortalized with HPV-16 are greatly enhanced in the 16 alpha-hydroxylation of estradiol as compared with normal cells. We suggest a model whereby the combined action of 16 alpha-hydroxylation of estrogen and HPV work together to promote cell proliferation.

Immunohistochemical analysis of estrogen receptors, progesterone receptors, Ki-67 antigen, and human papillomavirus DNA in normal and neoplastic epithelium of the uterine cervix

To investigate the relationship between the sex steroid receptor (estrogen receptor [ER] and progesterone receptor [PR]) status and the cell proliferation kinetics during the menstrual cycle in normal and neoplastic epithelium of the uterine cervix, immunohistochemical localization of ER, PR, and cell proliferation-associated antigen, Ki-67, was investigated in 35 normal cervical specimens, 3 condylomas, 26 cervical intraepithelial neoplasia (CIN) samples, and 22 invasive squamous carcinoma samples. The presence of human papillomavirus (HPV) DNA was also studied. In the normal cervix, basal cells were usually ER positive, PR negative, and Ki-67 negative throughout the menstrual cycle. Parabasal cells were ER positive and PR negative in the follicular phase, but ER negative and PR positive, and Ki-67 positive in the luteal phase, and Ki-67-positive cells increased in number in the luteal phase. In contrast, PR positivity was observed in the cells of condyloma (2 of 2 cases), CIN (19 of 26 cases), and invasive squamous carcinoma (13 of 22 cases) irrespective of the menstrual phase. Moreover, most neoplastic cells containing HPV DNA type 16/18 were ER negative, whereas several lesions containing HPV DNA type 31/33/35 were weakly ER positive. Many Ki-67-labeled cells were observed in the neoplastic lesions. These results suggest that reduced ER expression and increased PR expression are associated with the proliferation of normal cervical squamous epithelium, and this proliferation-related receptor status, which is probably induced by HPV infection, is usually expressed in neoplastic cervical squamous cells.