Association of oral contraceptive use and human papillomaviruses in invasive cervical cancers

Association between oral contraceptives and cervical cancer: A retrospective case-control study based on the National Health and Nutrition Examination Survey

Background: Cervical cancer is the fourth most common cancer among females globally, with a high incidence and high mortality among females in developing countries. This retrospective case-control study aimed to investigate the association between oral contraceptives and cervical cancer, on which insufficient evidence still exists. Material and Methods: To examine the association between oral contraceptives and cervical cancer based on 7,496 females aged over 20 years from the National Health and Nutrition Examination Survey, multivariable logistic regression conducted from 1999 to 2016 was used. Results: Contraceptive use was positively associated with cervical cancer risk. In model 1 (unadjusted), a 195% increased risk of cervical cancer was observed among those who used oral contraceptives (odds ratio [OR] = 2.27, 95% confidence interval [CI] = 1.39-3.98, p = 0.002) compared to those who did not. In addition, the ORs for the exposed population were 1.74 (95% CI = 1.05-3.08, p = 0.041) and 1.93 (95% CI = 1.16-3.44, p = 0.017) in model 2 (adjusted for age, race, and body mass index [BMI]) and model 3 (adjusted for education level, ratio of family income to poverty, drinking status, smoking status, number of pregnancies, age at first sex, number of sexual partners, and whether to receive the human papillomavirus (HPV) vaccine in addition to model 2), respectively. Furthermore, subgroup analyses stratified by age, smoking status, BMI, age at first sex, number of sexual partners, and whether to receive the HPV vaccine also revealed that oral contraceptives were significantly associated with cervical cancer. Conclusion: This study demonstrated that oral contraceptive use increased the risk of cervical cancer. In addition, the higher risk, including individuals older than 45 years, having a high BMI (≥30 kg/m2), being current smokers, and having more than five sexual partners, may contribute to the development of cervical cancer.

Combined Oral Contraceptive Use and the Risk of Cervical Cancer: Literature Review

Cervical cancer (CC) is caused by persistent infection of human papillomavirus of high oncogenic risk (hr-HPV); however, several cofactors are important in its carcinogenesis, such as smoking, multiparity, and prolonged use of oral hormonal contraceptives (COCs). Worldwide, 16% of women use COCs, whereas in Brazil this rate is of ∼ 30%. The safety and adverse effects of COCs are widely discussed in the literature, including the increase in carcinogenic risk. Due to the existence of several drugs, combinations, and dosages of COCs, it is hard to have uniform information in epidemiological studies. Our objective was to perform a narrative review on the role of COCs use in the carcinogenesis of cervical cancer. Several populational studies have suggested an increase in the incidence of cervical cancer for those who have used COCs for > 5 years, but other available studies reach controversial and contradictory results regarding the action of COCs in the development of CC.

Persistent HPV infection in postmenopausal age women

OBJECTIVE

Persistence of human papillomavirus (HPV) is associated with an increased risk of developing cervical SIL and cancer in young women. Because this association in older, postmenopausal age women has received little attention, we evaluated persistence of HPV among women in this age group.

METHODS

Women (n=105) ages 45-64 were examined annually for 7 years to evaluate HPV in cervical cytologic specimens. PCR, dot blot hybridization and DNA sequencing were used to detect HPV types.

RESULTS

The cumulative prevalence of HPV was 34%, and 24% had HPV high-risk oncogenic types which are associated with genital cancers. The most common oncogenic types were HPV-16 (72%) and HPV-31 (16%). The persistence rate of HPV infection was 16%. No specific risk factors were associated with repeat viral positivity.

CONCLUSION

Postmenopausal women are infected with persistent oncogenic HPV at a substantial rate, supporting the need for continued screening in postmenopausal women to detect preneoplastic genital lesions.

An interleukin-10 gene polymorphism associated with the development of cervical lesions in women infected with Human Papillomavirus and using oral contraceptives

Human Papillomavirus (HPV) infection plays a crucial role in the development of cervical lesions and tumors, however most lesions containing high-risk HPVs do not progress to cervical tumors. Some studies suggest that the use of oral contraceptives may increase the risk of cervical carcinogenesis, but this has not been confirmed by all the studies. Cytokines are important molecules that act in the defense of an organism against viral infections. Several genetic studies have attempted to correlate cytokine polymorphisms with human diseases, including cancer. The significance of IL10 polymorphisms for cancer is that they have both immunosuppressive and antiangiogenic properties. We aimed to investigate the role of promoter polymorphisms in the IL10 gene in women with cervical lesions associated with HPV infection, in the presence of the use of oral contraceptives. Using High Resolution Melt analysis (HRM), we analyzed an SNP -1082A/G and -819C/T in interleukin-10 promoter region in 364 Brazilian women: 171 with cervical lesions and HPV infection, and 193 with normal cytological results and HPV-negative. We observed no significant differences in genotype and allele frequencies in the two loci between patients and healthy controls. Furthermore, in the haplotype analysis of IL10, we found that CA haplotype was significantly more frequent in patients infected with HPV than in the control group (p = 0.0188). We did not find any genotype and allelic association of the IL10 gene polymorphisms between cases and controls. However, in this study, when the HPV-positive patients were stratified according to their use of contraceptives, we found a significant association between the -1082G allele (p = 0.0162) and -1082GG genotype (p = 0.0332) among HPV-infected patients who used oral contraceptives. Our findings suggest that -1082A/G gene polymorphism represents a greater susceptibility to progressive cervical lesions in HPV- infected women who use oral contraceptives.

Human papillomavirus genotype distribution and risk factors for infection in women from a small municipality in north east Brazil

In order to assess the prevalence of human papillomavirus (HPV) infection, the HPV genotypes and factors associated with infection, we conducted a population-based survey in a small municipality in north east Brazil among women aged between 12 and 49 years. A questionnaire regarding socioeconomic variables, reproductive life and sexual behaviour was used, and women were examined gynaecologically, followed by collection of vaginal lavage with saline solution for HPV DNA determination. HPV DNA was detected by the Digene® SHARP SignalTM-System, and further genotyped by INNO-LiPA Genotyping System®. Of 579 women, HPV infection was present in 68 (prevalence: 11.7%; 95% CI: 9.3–14.7). The most common HPV types were 16, 31 and 74, each accounting for 14.7% of infections. Of all HPV-positive women, 35.3% showed multiple HPV genotypes. Variables independently associated with HPV infection were: ≥3 partners in life (adjusted OR [aOR]: 3.06; 95% CI: 1.68–5.60) and the use of oral contraception in the last 12 months (aOR: 2.39; 95% CI: 1.33–4.30). Previous participation in a cervical cancer screening programme was protective (aOR: 0.28; 95% CI: 0.13–0.60). HPV infection is common among women from rural Brazil, and HPV genotypes identified indicate that immunization could be an important preventive measure in this population.

Incidence, mortality, and prognostic factors of small cell carcinoma of the cervix

OBJECTIVE

To compare the incidence, mortality, and presentation of small cell carcinoma of the cervix with other histologies.

METHODS

From 1977 to 2003, 290 women with small cell carcinoma of the cervix uteri were identified from the Surveillance, Epidemiology, and End Results database. Also, 27,527 patients with squamous cell carcinoma of the cervix and 5,231 patients with adenocarcinoma of the cervix were identified for comparison. The annual incidence was calculated and examined for trend. Patient and disease characteristics were compared among histologies. Univariable analyses were conducted using the log-rank test. Multivariable analysis was performed using Cox regression.

RESULTS

The mean annual incidence for small cell carcinoma was 0.06 per 100,000 women, compared with 6.6 and 1.2 for squamous cell carcinoma and adenocarcinoma, respectively. There were significant differences at presentation between small cell carcinoma compared with squamous cell carcinoma and adenocarcinoma for race, treatment, International Federation of Gynecology and Obstetrics stage, and lymph node involvement (P<.05). A trend for improved survival was identified for adenocarcinoma (P=.036) and squamous cell carcinoma (P<.001) but not for small cell carcinoma (P=.672). Five-year survival for small cell carcinoma (35.7%) was worse compared with squamous cell carcinoma (60.5%, hazard ratio 0.55; 95% confidence interval (CI) 0.43-0.69) and adenocarcinoma (69.7%, hazard ratio 0.48; 95% CI 0.37-0.61). On multivariable analysis, age, stage, and race were prognostic for survival in women with small cell carcinoma (P<.05).

CONCLUSION

Small cell carcinoma is a rare histology of cervical cancer associated with a worse prognosis and a predilection for nodal and distant metastasis. The decrease in survival was marked in early-stage and node-negative patients. Because of the high rates of nodal involvement even with early-stage disease, multimodality treatment with radiotherapy and chemotherapy should be considered.

LEVEL OF EVIDENCE

II.

Relationship of cytopathology and cervical infection to outcome of in-vitro fertilization and embryo transfer

OBJECTIVE

To determine whether a relationship exists between in-vitro fertilization and embryo transfer (IVF-ET) outcome and cervical infection or presence of human papillomavirus (HPV).

METHOD

Cervical scrapes, digital colposcopies, and cervical biopsies were performed in 1044 Chinese women undergoing IVF for tubal infertility or, in their partners, abnormal semen. The pregnant (n=415) and nonpregnant (n=629) groups differed neither in clinical signs of cervical inflammation nor in rate of HPV detection.

RESULTS

There were no associations between IVF-ET outcome and infection rate, degree of cytopathologic abnormality, detection of HPV, or results of digital colposcopy and cervical biopsy. Cytologic results did not correlate with any of the clinical parameters of IVF-ET.

CONCLUSIONS

No association was found between IVF-ET outcome and cervical infection, cytopathologic result, HPV detection, or result from the colposcopy or biopsy. Extensive testing and treatment for cervical infection do not appear necessary in IVF-ET candidates.

Upregulation of CD44 expression by interleukins 1, 4, and 13, transforming growth factor-β1, estrogen, and progestogen in human cervical adenocarcinoma cell lines

Although cervical adenocarcinoma constitutes approximately 10-20% of primary malignant tumors of the uterine cervix, its pathogenesis is less well understood than that of the corresponding squamous cancer. CD44 is a cell surface glycoprotein postulated to play a role in many biologic processes including tumor growth and metastasis. We have previously reported from immunohistochemical studies that a particular CD44 variant (CD44v5) is consistently overexpressed in endocervical neoplasia. It thus has potential as a diagnostic marker and even as a target for therapeutic approaches directed against specific epitopes. The aim of this study was to investigate which cytokines and hormones are capable of modulating CD44v5 expression, using a cell culture model. The effects of interleukin (IL)-1alpha, IL-1beta, IL-4, IL-13, transforming growth factor (TGF)-beta1, estrogen, and progestogen on CD44v5 expression were examined in cultures of three human cervical adenocarcinoma cell lines (HeLa, HeLa229, and HS588T). Expression was assessed using dual fluorescence-labeled flow cytometry and western blotting techniques. It was found that incubation of cultures for 72 h with IL-1alpha, IL-1beta, IL-4, IL-13, TGF-beta1 (all at 0.1-10 ng/mL), estrogen (5-10 ng/mL), or progestogen (5-20 ng/mL) induced significant upregulation of CD44v5. These factors are likely to exert a similar stimulatory influence in vivo and may contribute to the process of carcinogenesis.

Evaluation of tamoxifen in persistent or recurrent nonsquamous cell carcinoma of the cervix: a Gynecologic Oncology Group study

This study was undertaken to estimate the antitumor activity of tamoxifen in patients with persistent or recurrent nonsquamous cell carcinoma of the cervix. Furthermore, the nature and degree of adverse effects from tamoxifen in this cohort of individuals was examined. Tamoxifen citrate was to be administered at a dose of 10 mg per orally twice a day until disease progression or unacceptable side effects prevented further therapy. A total of 34 patients (median age: 49 years) were registered to this trial; two were declared ineligible. Thirty-two patients were evaluable for adverse effects and 27 were evaluable for response. There were only six grades 3 and 4 adverse effects reported: leukopenia (in one patient), anemia (in two), emesis (in one), gastrointestinal distress (in one), and neuropathy (in one). The objective response rate was 11.1%, with one complete and two partial responses. In conclusion, tamoxifen appears to have minimal activity in nonsquamous cell carcinoma of the cervix.

Human papillomavirus infection of the cervix uteri in women attending a Health Examination Center of the French social security

Since human papillomavirus (HPV) is the central causal factor in cervical cancer, understanding the epidemiology of this infection constitutes an important step towards development of strategies for prevention. Six hundred and fifty seven cervical samples were tested for HPV using PCR with consensus primers (MY09/MY11), by genotyping (restriction and sequencing analyses) and by cervical cytology, from women who attended a Health Examination Center of the French social security. Women with no cervical smear as well as women with cytological abnormalities within the last 3 years were recruited. HPV DNA was detected in 7.3% of the women (5.3% for high-risk, 2.4% for low-risk, and 0.5% for unknown risk types) including 6 (0.9%) mixed infections. Fifteen different genotypes were detected, of which genotypes 16 (22.2%), 58 (13.0%), 18 (11.1%), 30 (9.2%), and 33 (9.2%) were the most prevalent. In age group 17-25 years, we found the highest frequencies for both any (22.1%) and high-risk (14.7%) HPV, and prevalences gradually decreased with age. 5.2% of low-grade squamous intraepithelial lesion, 0.3% of high-grade squamous intraepithelial lesion, and 1.2% of atypical squamous cells of undetermined significance were found. The frequencies of high risk and all HPV types were significantly higher in squamous intraepithelial lesions than in those with normal and reactive/reparative changes (P < 0.0001). The prevalence of high-risk HPV in the atypical squamous cells of undetermined significance/low-grade squamous intraepithelial lesion group (28.6%) was significantly higher than in the normal and reactive/reparative changes groups (3.4%) (P < 0.0001). HPV detection was associated with younger age, single marital and non-pregnant status (P < 0.0001), premenopausal status (P = 0.0004), and contraception (P = 0.0008). Marital status (OR 4.5; 95% CI = 2.3-9.0) and tobacco consumption (OR 3.0; 95% CI = 1.6-5.7) were predictive independent factors of HPV infection. The French system of Health Examination Centers might be of interest for following women regularly, especially those with a low socioeconomic status.

The role of steroid contraceptive hormones in the pathogenesis of invasive cervical cancer: a review

Invasive cervical cancer remains a leading cause of morbidity and mortality, especially among women in the developing world where screening is either deficient or absent. Of all agents linked to the causation of this disease, high-risk human papillomavirus (HPV) appears to be the strongest factor. However, not all women with HPV develop cervical cancer. Steroid contraception has been postulated to be one mechanism whereby HPV exerts its tumorigenic effect on cervical tissue. Steroids are thought to bind to specific DNA sequences within transcriptional regulatory regions on the HPV DNA to either increase or suppress transcription of various genes. Although some earlier studies were reassuring as no increased incidence of cervical cancer was observed, subsequent research has shown a causative association, especially among long-term users. The role of steroids was further enhanced by the discovery of hormone receptors in cervical tissue. Some earlier studies of oral contraceptive steroids found no increased risk, even after controlling for other risk factors, including smoking and number of partners. However, prospective studies have shown a greater progression of dysplasia to carcinoma-in-situ with more than 6 years of oral steroid contraceptive use. Similar findings were also evident from other work, including the Royal College of General Practitioners Oral Contraception Study. The WHO Collaborative Study of Neoplasia and Steroid Contraceptives showed a relative risk of 1.2 for invasive cancer in users of the long-acting progestational contraceptive, depo-medroxyprogesterone acetate. However, in users of more than 5 years duration, an estimate of 2.4 was reported. The upstream regulatory region (URR) of the HPV type 16 viral genome, mediates transcriptional control of the HPV genome and is thought to contain enhancer elements that are activated by steroid hormones. It has been shown that steroid hormones bind to specific glucorticoid-response elements within HPV-DNA. Experimental evidence has revealed that high-risk type HPV 16 are able to stimulate the development of vaginal and cervical squamous cell carcinomas in transgenic mice exposed to slow-release pellets of 17 beta-estradiol in the presence of human keratin-14 promoter. Squamous cell carcinomas developed in a multi-stage pathway only in transgenic mice and not in nontransgenic mice. The E6 oncoprotein of HPV 16 has been shown to bind to the p53 tumor suppressor gene and stimulate its degradation by a ubiquitin-dependent protease system. Steroid hormones are thought to increase the expression of the E6 and E7 HPV 16 oncogenes, which in turn bind to and degrade the p53 gene product, leading to apoptotic failure and carcinogenesis. However, the molecular basis of this remains to be proven.

Comparison of the basal and glucocorticoid-inducible activities of the upstream regulatory regions of HPV18 and HPV31 in multiple epithelial cell lines

Steroid hormone receptors have been shown to bind to response elements in the upstream regulatory region (URR) of human papillomavirus (HPV) in a ligand-dependent manner to affect viral promoter activity. To better understand how the enhancer activity of the URR differs between high risk HPV types, we chose to compare the basal and glucocorticoid-dependent activities of the URRs of HPV18 and HPV31. We found that the URR of HPV18 is a stronger enhancer than the URR of HPV31 in six different cell lines of epithelial origin. Furthermore, the activity of the URR of HPV31 was not inducible by the synthetic glucocorticoid dexamethasone (dex) in any cell line tested, while the URR of HPV18 was dex-inducible in the majority of these lines. These studies indicate significant differences between the URRs of high risk HPV types.

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.

In vivo tissue-specific regulation of the human papillomavirus type 18 early promoter by estrogen, progesterone, and their antagonists

Human papillomavirus type 18 is a causative agent of epithelial cancers in the uterine cervix. We show here that estrogen and progesterone activate beta-galactosidase expression from the early promoter of this virus in the genital epithelia of transgenic mice. Ovariectomy caused suppression of transgene expression exclusively in vagina and cervix epithelia. Beta-galactosidase expression could be restored in ovariectomized females by administration of estrogen, alone or in combination with progesterone. Further, rescue of transgene expression was inhibited by the estrogen antagonist tamoxifen and the anti-progesterone RU486, suggesting that this was a specific effect.

Prevalence and epidemiologic correlates of atypical squamous cells of undetermined significance in women at low risk for cervical cancer

Our aim was to determine the prevalence and epidemiologic correlates of atypical squamous cells of undetermined significance (ASCUS) in a population at low risk for cervical cancer in Porto Alegre, Brazil. Sociodemographic data and gynecological and obstetrical history from 977 women screened at an outpatient clinic were recorded. Specimens were collected for Papanicolaou cervical cytology, colposcopy, and biopsy (if indicated). Sixty-two (6.3%) patients presented ASCUS, 21 (2.1%) presented low-grade squamous intraepithelial lesions, and 6 (0.6%) presented high-grade lesions. Presence of human papillomavirus (HPV) DNA in cervical cells (odds ratio (OR) = 1.57; confidence interval (CI) 95% = 1.11-2.23), history of HPV infection (OR = 3.12; CI 95% = 1.22-7.96), and becoming sexually active at 18 yr or younger (OR = 1.70; CI 95% = 1.15-2.51) were independently associated with ASCUS. ASCUS patients reported HPV infections and presented HPV DNA in cervical cells more often than did patients with normal cytology; therefore, they should be carefully monitored to ensure early detection of cancer precursor lesions and prevention of cervical cancer.

Chien-Tien Hsu Memorial Lecture. Fertility and gynaecologic malignancies

Fertility and gynaecological malignancies have an important relationship. A clear inverse relationship exists between family size and the incidence of ovarian and endometrial cancer. Current methods of fertility control have an influence on subsequent development of various gynaecological malignancies. A slightly increased risk of breast cancer has been reported in current users and those who had used hormonal contraceptives (OCs) within 10 years; this risk declined with time and disappeared after 10 years. Women who started OC before age 20 had a higher relative risk; the disease did not spread beyond the breast in the majority. Most studies found OC to reduce the risk of ovarian and endometrial cancer. The relative risks of squamous cell carcinoma and adenomatous carcinoma of the cervix have been reported to be 1.3 and 1.5, respectively in ever-users of OCs; however, the aetiology of cervical cancer is multifactoral. Several reports suggest the beneficial effect of tubal ligation and breast feeding in reducing the risk of ovarian cancer. Therapy of gynaecological malignancies may have an influence on subsequent fertility. Amenorrhoea developing after treatment of hydatidiform mole may be due to choriocarcinoma, recurrent mole or a normal pregnancy. Choriocarcinoma can also develop after a partial mole. The risk of fetal teratogenicity from chemotherapy is present only if conception occurs during or immediately following the treatment cycles. Fertility is not impaired following chemotherapy. Successful pregnancies have occurred in women who have had widespread GTD including cerebral metastases. In the young patient with gynaecological malignancy preservation of fertility is possible. Fertility-sparing surgery may be safe in early ovarian epithelial cancers and even in advanced germ cell tumours. Recently, the fertility-sparing surgery of radical trachelectomy and pelvic lymphadenectomy has been carried out for early invasive cervical cancer in young women. Gynaecological cancer occurring in pregnancy is uncommon; it presents the clinician with a difficult situation to manage. In most instances the cancer is treated as though the patient is not pregnant; the timing and mode of delivery needs individualization. The overall prognosis for breast cancer complicating pregnancy is poor. Survival in cervical cancers diagnosed antepartum is similar to the non-pregnant patient. Ovarian cancer in pregnancy has a good prognosis because of the early stage at diagnosis.

Smoking, diet, pregnancy and oral contraceptive use as risk factors for cervical intra-epithelial neoplasia in relation to human papillomavirus infection

Smoking, nutrition, parity and oral contraceptive use have been reported as major environmental risk factors for cervical cancer. After the discovery of the very strong link between human papillomavirus (HPV) infection and cervical cancer, it is unclear whether the association of these environmental factors with cervical cancer reflect secondary associations attributable to confounding by HPV, if they are independent risk factors or whether they may act as cofactors to HPV infection in cervical carcinogenesis. To investigate this issue, we performed a population-based case-control study in the Vasterbotten county of Northern Sweden of 137 women with high-grade cervical intra-epithelial neoplasia (CIN 2-3) and 253 healthy age-matched women. The women answered a 94-item questionnaire on diet, smoking, oral contraceptive use and sexual history and donated specimens for diagnosis of present HPV infection (nested polymerase chain reaction on cervical brush samples) and for past or present HPV infections (HPV seropositivity). The previously described protective effects of dietary micronutrients were not detected. Pregnancy appeared to be a risk factor in the multivariate analysis (P < 0.0001). Prolonged oral contraceptive use and sexual history were associated with CIN 2-3 in univariate analysis, but these associations lost significance after taking HPV into account. Smoking was associated with CIN 2-3 (odds ratio (OR) 2.6, 95% confidence interval (CI) 1.7-4.0), the effect was dose-dependent (P = 0.002) and the smoking-associated risk was not affected by adjusting for HPV, neither when adjusting for HPV DNA (OR 2.5, CI 1.3-4.9) nor when adjusting for HPV seropositivity (OR 3.0, CI 1.9-4.7). In conclusion, after taking HPV into account, smoking appeared to be the most significant environmental risk factor for cervical neoplasia.

Regulation of cell growth and HPV genes by exogenous estrogen in cervical cancer cells

Human papillomavirus (HPV) infection is known as the major cause of the development of cervical cancer. The E6 and E7 proteins of oncogenic HPV can play critical roles in immortalization and malignant transformation of cervical epithelial cells. From the previous epidemiologic data, it has been determined that long-term use of oral contraceptives may be a risk factor for cervical cancer. Investigation of the estrogenic and antiestrogenic effects on the proliferation of cervical cancer cells and the gene expression of HPV would help to explain the role of estrogen in the HPV-associated pathogenesis of cervical cancer. In this study, cervical cancer cells (HeLa, CaSki, and C33A) were cultured in vitro in the presence of 17beta-estradiol or tamoxifen to observe their regulatory growth effect and HPV E6/E7 gene expression. The estrogenic effect on the promoter activity of HPV URR was further confirmed by transient transfection assay, which was conducted in C33A cells using the HPV-18 URR-CAT reporter plasmid. The supplemental effect of estrogen receptors on URR promoter activity was also evaluated. The proliferation of HeLa and CaSki cells was stimulated by estradiol at physiologic concentration levels (</=1 x 10-6 M). At a low concentration (0.1 x 10-6 M), tamoxifen also stimulated the proliferation of HeLa and CaSki cells. In contrast to HPV-positive cervical cells, the proliferation of C33A was not influenced by exogenous estradiol or tamoxifen, indicating that HPV might play a role in the hormonal stimulation of cell growth. Interestingly, the proliferation of HeLa was markedly suppressed at high concentrations of estradiol and tamoxifen (5 and 10 x 10-6 M). The levels of HPV-18 E6 and E7 mRNA were significantly increased by estradiol at a concentration of 0.5 x 10-6 M. Transient transfection experiments using the HPV URR-CAT reporter plasmid in C33A cells indicated that the expression of HPV E6/E7 genes was increased by the treatment of estradiol and tamoxifen. Co-transfection of estrogen receptors (ER) and URR-CAT leads to a fourfold increase in CAT activity by estradiol or tamoxifen at physiologic concentrations. When estradiol or tamoxifen was administered at high concentrations (5 x 10-6 M), a DNA ladder, typically indicative of apoptosis, was observed in HeLa cells. In conclusion, estradiol stimulated the growth of HPV-positive cervical cancer cells, as did tamoxifen at low concentrations (0.1 x 10-6 M). The growth stimulation of HPV-positive cervical cancer cells by estrogen appeared to be related to the increased expression of HPV E6/E7. Growth suppression observed at high concentrations of estradiol and tamoxifen in HeLa cells might be a result of apoptosis. Taken together, these data suggested that exogenous estradiol might be a risk factor in HPV-mediated cervical carcinogenesis.

Risk factors for pre-cancerous lesions of the cervix

Studies on risk factors for pre-cancerous lesions of the uterine cervix have shown strong association with sexual practice. Women with multiple sexual partners and intercourse at early age are at high risk. A role of male partners in further enhancing the risk has been identified. All these support the hypothesis relating to a sexually transmissible aetiological agent. An extensive review of the literature on the risk factors for pre-cancerous lesions of cervix has been carried out. The risk factors were grouped into genital, sexual, chemical, dietary and life factors. Human papilloma virus (HPV) is the major infectious aetiological agent associated with the development of pre-cancerous lesions of cervix. Other co-factors such as multiple sexual partners of the male as well as the female and early age of first intercourse are also involved at the critical aetiological step of progression from low-grade to high-grade lesions. The role of other infectious agents in terms of supportive or interactive effects is not clear. No independent effect for herpes simplex virus 2 on risk is observed. Other risk factors include cigarette smoking, oral contraceptive usage, certain nutritional deficiencies and poor personal hygiene. However, it is not clear whether these factors operate independently from HPV. There is no consistency in the independent effect of these factors on the development of low- to high-grade lesions of cervix. There is a similarity in the patterns of risk between pre-cancerous lesions of the cervix and cervical cancer. Monogamy, late commencement of sexual activity, personal hygiene and use of barrier contraceptive methods help towards primary prevention. In the long-term, primary prevention of cervical neoplasia through HPV immunization of population may be a possibility.

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.

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.

Regulation of human papillomavirus type 18 in vivo: effects of estrogen and progesterone in transgenic mice

We examined the in vivo effect of estrogen, progesterone, RU 486, and pregnancy on the upstream regulatory region (URR) of human papillomavirus (HPV) 18 transgenic mice. The mice contain the bacterial reporter beta-galactosidase gene under control of the HPV 18 URR. Pregnant transgenic mice were sacrificed on various days of gestation and the level of URR activation was determined. Another group of female transgenic mice was ovariectomized at 4 to 6 weeks of age. Pellets of estradiol, progesterone, progesterone + RU 486, or placebo were implanted 1 to 2 weeks after ovariectomy. Mice were sacrificed after pellet implantation to examine acute and chronic effects. Marked increases in URR activation during pregnancy were observed. Progesterone was found to activate the URR acutely. Significantly higher activation was demonstrated at 24 hr in the progesterone group compared to placebo (P < 0.01). Activation with progesterone at 24 hr was significantly higher than at any other time point (P < 0.001). A trend toward decreasing activation over time was demonstrated in the progesterone group (r = -0.87, P = 0.0001). RU 486 does not block the activation of progesterone in our model. Estradiol activates the URR acutely compared to placebo (P = 0.034). This in vivo model demonstrates activation of the URR in response to exogenous estrogen, progesterone, and pregnancy. These data may have clinical implications for women who harbor high-risk HPV.

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.

Papillomavirus infections--a major cause of human cancers

The papillomavirus family represents a remarkably heterogeneous group of viruses. At present, 77 distinct genotypes have been identified in humans and partial sequences have been obtained from more than 30 putative novel genotypes. Geographic differences in base composition of individual genotypes are generally small and suggest a low mutation rate and thus an ancient origin of today's prototypes. The relatively small size of the genome permitted an analysis of individual gene functions and of interactions of viral proteins with host cell components. Proliferating cells contain the viral genome in a latent form, large scale viral DNA replication, as well as translation and functional activity of late viral proteins, and viral particle assembly are restricted to differentiating layers of skin and mucosa. In humans papillomavirus infections cause a variety of benign proliferations: warts, epithelial cysts, intraepithelial neoplasias, anogenital, oro-laryngeal and -pharyngeal papillomas, keratoacanthomas and other types of hyperkeratoses. Their involvement in the etiology of some major human cancers is of particular interest: specific types (HPV 16, 18 and several others) have been identified as causative agents of at least 90% of cancers of the cervix and are also linked to more than 50% of other anogenital cancers. These HPV types are considered as 'high risk' infections. Their E6/E7 oncoproteins stimulate cell proliferation by activating cyclins E and A, and interfere with the functions of the cellular proteins RB and p53. The latter interaction appears to be responsible for their mutagenic and aneuploidizing activity as an underlying principle for the progression of these HPV-containing lesions and the role of high risk HPV types as solitary carcinogens. In non-transformed human keratinocytes transcription and function of viral oncoproteins is controlled by intercellular and intracellular signalling cascades, their interruption emerges as a precondition for immortalization and malignant growth. Recently, novel and known HPV types have also been identified in a high percentage of non-melanoma skin cancers (basal and squamous cell carcinomas). Similar to observations in patients with a rare hereditary condition, epidermodysplasia verruciformis, characterized by an extensive verrucosis and development of skin cancer, basal and squamous cell carcinomas develop preferentially in light-exposed sites. This could suggest an interaction between a physical carcinogen (UV-part of the sunlight) and a 'low risk' (non-mutagenic) papillomavirus infection. Reports on the presence of HPV infections in cancers of the oral cavity, the larynx, and the esophagus further emphasize the importance of this virus group as proven and suspected human carcinogens.

Spontaneous genomic fragility and cell cycle progression in lymphocytes of patients with cervical carcinoma

Thirty patients with invasive carcinoma of the cervix, along with 15 age-matched healthy females as controls, were studied to examine the frequency of spontaneous SCEs, chromosomal aberrations (CAs), and cell cycle progression in lymphocytes. The frequency of SCEs and TCAs was statistically significant in the patients over the control group. The correlation of SCEs and TCAs with the stage of cancer, age, and number of pregnancies was also made. The cell cycle of lymphocytes showed its prolongation in the patients, as is evident from the higher proportion of cells at M1 (metaphase of first cell division after 72 hours).

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.

Risk of dysplasia in anal condyloma

BACKGROUND

Recent studies suggest an alarming incidence of dysplasia in homosexuals with anal condyloma. The purpose of our study was to determine the incidence of dysplasia in anal condyloma in our male patients and to determine risk factors for premalignant or malignant change.

METHODS

Between 1986 and 1994, 103 male patients were referred to our colorectal clinic for evaluation of anal condyloma. Ninety-one patients had biopsy for pathology and form the basis of this report. All charts were reviewed and results analyzed using the chi-squared test with the Yates correction factor.

RESULTS

Mean patient age was 31 +/- 11 years (range, 13 to 78 years) and mean duration of disease was 20 +/- 26 months (range, 2 to 120 months). There were 59 heterosexuals and 32 homosexuals/bisexuals. Two heterosexuals (3%) had invasive squamous cell carcinoma and four (6%) had dysplasia. One homosexual/bisexual (3%) had squamous cell carcinoma in situ and nine (28%) had dysplasia (p < 0.05). Statistical analysis revealed that HIV seropositive status and disease location above the dentate line also predicted increased risk of dysplasia, whereas duration of disease, previous topical therapy, substance abuse, and other sexually transmitted diseases were not significant risk factors.

CONCLUSIONS

Homosexual orientation, disease above the dentate line and HIV seropositivity increase the risk of dysplasia in perianal condyloma. The incidence of dysplasia in perianal condyloma is significant enough to warrant consideration of biopsy in all patients.

Smoking, alcohol, sexual behaviour and drug use in women with cervical human papillomavirus infection

OBJECTIVE

The aim of the study was to determine if smoking is associated with cervical human papillomavirus infection (CHPI) independent of sexual risk factors.

SETTING

Two family planning clinics and one youth clinic in Sweden.

SUBJECTS

Human papillomavirus (HPV) DNA was found in cervical samples of 66 (6.8%) of 972 women attending for contraceptive advice, using Southern blot tests.

RESULTS

Among women with cervical human papillomavirus infection (CHPI), 33 (50%) were smokers, as compared to 307 (33.9%) among a comparison group of HPV-negative women (odds ratio = 2.0, 95% CI = 1.2-3.2). After stepwise adjustment for number of lifetime partners, number of partners last six months, age at first intercourse, alcohol use, drug abuse and history of or current sexually transmitted disease other than CHPI, the odds ratio decreased to 1.4 (95% CI = 0.8-2.4). Recent use of alcohol and ever use of narcotics were also significantly correlated to CHPI in crude analyses, but vanished in multifactorial analyses after adjustment for the mentioned sexual risk behavioral factors.

CONCLUSIONS

The results of this study indicate that smoking, alcohol and drug abuse are risk markers, but not causal factors, for CHPI.

Primary prevention of gynecologic cancers

A shift from treatment to prevention of the three major gynecologic cancers is overdue. The traditional approach to cervical, endometrial, and ovarian cancers has been secondary or tertiary prevention--early detection and treatment or mitigation of damage, respectively. We reviewed the literature on these cancers to identify strategies for primary prevention. Cervical cancer behaves as a sexually transmitted disease. As with other such diseases, barrier and spermicidal contraceptives lower the risk of cervical cancer; the risk reduction approximates 50%. Combination oral contraceptives help prevent both endometrial and epithelial ovarian cancers. The risk of endometrial cancer among former oral contraceptive users is reduced by about 50% and that of ovarian cancer by about 30% to 60%. Weight control confers strong protection against endometrial cancer. Breast-feeding and tubal sterilization also appear to protect against ovarian cancer. Although women have a range of practical, effective measures available to reduce their risk of these cancers, few are aware of them. Without this information, women cannot make fully informed decisions about their health.

Cervical carcinoma in situ and use of depot-medroxyprogesterone acetate (DMPA). WHO Collaborative Study of Neoplasia and Steroid Contraceptives

The relationship of depot-medroxyprogesterone acetate (D-MPA) use to risk of cervical carcinoma in situ was investigated using data from a large multi-national, hospital-based case-control study. To avoid possible detection bias from Pap smear screening, final analyses were restricted to a subset of cases with symptoms at the time of their diagnosis of cervical carcinoma in situ. Relative to nonusers, the risk was elevated in women who had ever used DMPA and increased with duration of use. Decreasing trends in relative risk with times since first and last uses were observed in long-term users. Results from another portion of this same study did not show a relationship of invasive cervical cancer to DMPA use. These findings suggested that if DMPA increases the risk of cervical carcinoma in situ then either this is a reversible effect, or the cervical lesions induced by DMPA tend not to progress to invasive disease.

Detection of human papillomavirus by nonradioactive hybridization

The presence of the human papillomavirus (HPV) DNA sequence in cervical smears of women with cervical intraepithelial neoplasia (CIN) was investigated through dot blot using a nonradioactive method based on the principle of enhanced chemiluminiscence. From 154 samples examined, 59 (38.3%) had HPV-related sequences determined by dot-blot hybridization; among these, 18 samples (11.68%) reacted either to HPV 6/11 or to HPV 16/18 probes, 20 (12.98%) reacted to only HPV 16/18, and 21 (13.63%) reacted exclusively to HPV 6/11. The relative sensitivity of the method was controlled comparing the results of both tests with those obtained by Southern blot in 32 samples. The risk of HPV positivity was increased in women who first had intercourse at an early age and in patients with CIN II or III. Both associations were significant at the 95% confidence interval (CI). An increased risk of HPV positivity was also associated with patient's age at diagnosis, education levels, number of sexual partners, and use of oral contraceptives, but none of these factors were significant at 95% CI. Other risk factors for cervical cancer, such as the number of pregnancies or cigarette smoking, were not found to be associated with HPV infection and indicate that the association of these factors with cervical cancer probably is independent of HPV infection. Even if HPV is the major risk factor for CIN, this also supports a multifactorial model of cervical cancer etiology with an increased risk of HPV infection.

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.

Invasive squamous-cell cervical carcinoma and combined oral contraceptives: results from a multinational study. WHO Collaborative Study of Neoplasia and Steroid Contraceptives

Data from a hospital-based case-control study collected in 11 participating centers in 9 countries were analyzed to determine whether use of combined oral contraceptives alters risk of invasive squamous-cell cervical cancer. Information on prior use of oral contraceptives, screening for cervical cancer, and suspected risk factors for this disease were ascertained from interviews of 2361 cases and 13,644 controls. A history of smoking and anal and genital warts was obtained, and blood specimens were collected for measurement of antibodies against herpes simplex and cytomegaloviruses, from selected sub-sets of these women, as was a sexual history from interviews of husbands. The relative risk of invasive squamous-cell cervical carcinoma was estimated to be 1.31, with a 95% confidence interval that excluded one, in women who ever used combined oral contraceptives. Risk of this disease increased significantly with duration of use after 4 to 5 years from first exposure, and declined with the passage of time after cessation of use to that of non-users in about 8 years. No sources of bias or confounding were identified that offered plausible explanations for these findings. The strength of these results, and their consistency with those from other studies, suggest that a causal relationship may exist between use of combined oral contraceptives and squamous-cell cervical carcinoma. Women who have used these products for 4 or more years, and who most recently used them within the past 8 years, should receive high priority for cervical cytologic screening.

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.

The detachment cascade during metastasis

The cause of detachment of tumour cells during metastasis is still one of the most intriguing questions of tumour propagation. A hypothesis is suggested herein for lysis of extracellular matrix that could ultimately lead to the detachment and spreading of malignant cells. According to this theory a certain optimal estrogen level initiates a series of enzymatic activations that culminate in detachment and spreading of tumour cells.

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.

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.

Oral contraceptive use and human papillomavirus infection in women without abnormal cytological results

Both experimental and epidemiological data support the idea that oral contraceptive (OC) use may have a stimulating effect to a certain point on cervical carcinogenesis. The current investigation tries to answer the question whether OC use might have an influence on early human papillomavirus (HPV) infections. A total of 425 women without abnormal cytological results were examined colposcopically, and filter in situ hybridisation (FISH) was used to determine the presence of human papillomavirus (HPV) types 6, 11, 16 and 18. Eighty-one cervical specimens (19.1%) were found to be positive for one or more of the HPV types in FISH. HPV positivity was found to correlate with age and parity, being the highest among women under 25 and with less than two births. The use of OCs was inversely correlated with the presence of ectopy or dysplasia in this group of women. On the other hand, HPV positivity was not significantly higher among OC users than among non-users in any colposcopic group. Neither the type of pill used, nor the duration of use had any significant effect on HPV positivity. Further investigations are needed to evaluate the effects of OC use on more severe HPV-induced cervical lesions.

Prevalence of genital human papillomavirus infection in Wellington women

OBJECTIVES

To determine prevalence of human papillomavirus (HPV) in Wellington women, to identify risk factors for HPV infection, to correlate presence of HPV with cervical cytology, and to identify characteristics of women infected with HPV but with normal cytology.

DESIGN

Demographic, social, personal and clinical data were collected by a confidential self-administered coded questionnaire. The presence of DNA from HPV types 6/11, 16 + 18 and 31 + 33 in cervical scrapes was determined by dot-blot DNA hybridisation. All data were correlated with cervical cytology results.

SETTING AND SUBJECTS

Two thousand and twenty one women attending family planning clinics in the Wellington region participated in the study. The mean age of participants was 26 years, 33.3% currently smoked, 72.3% used hormonal contraceptives, 31.4% were married, and 91.4% were of European origin.

RESULTS

We found 10.9% of the study group infected with HPV. HPV types 16 and/or 18 predominated, being detected in 71.5% of HPV-positive women either alone or with other types. Of those infected 26.2% had multiple infections. Dysplasia (n = 87) or atypia (n = 84) were observed in 26.7% of infected women (n = 221) and 6.25% of uninfected women (n = 1792). Over 8% of women with normal smears were HPV positive, and types 16/18 were most common in these women.

CONCLUSIONS

Women with cervical dysplasia or atypia were six times more likely to have HPV infection than other women. The main risk factor for HPV infection, particularly with types 16 and/or 18, was multiple (> 5) sexual partners in the last year independent of other variables. Multivariate analysis of data showed no independent association between HPV infection and ethnicity, educational background, smoking history, marital status, contraceptive use, age at first sexual intercourse, or number of lifetime sexual partners.

Genital papillomavirus infection and cervical dysplasia--opportunistic complications of HIV infection

Certain human genital papillomaviruses (HPV) are strongly associated with cervical dysplasia and cancer. Evidence is accumulating that HPV infection and ano-genital cancers are more common in patients with the acquired immunodeficiency syndrome. The objective of our study was to evaluate the extent to which HPV infection and associated cervical disease constitute opportunistic complications of human immunodeficiency virus (HIV) infection in a population of sexually promiscuous, HIV-infected women in Kinshasa, Zaire. In 1989 we obtained Pap smears and cervicovaginal lavage specimens for HPV DNA testing from 47 HIV-seropositive and 48 HIV-seronegative prostitutes who were part of a cohort under observation since 1988. Thirty-eight percent of the HIV-seropositive and 8% of the seronegative women (odds ratio = 6.8; p = 0.001) had HPV DNA detected by either ViraType, a dot-blot assay which detects specific genital HPV types, or low-stringency Southern blot, which detects all HPV types. Eighty-two women (86%) had an interpretable Pap smear; 11 of 41 (27%) HIV-seropositive women and one of 41 (3%) seronegative women had cervical intra-epithelial neoplasia (CIN) (odds ratio = 14.7; p = 0.002). HIV seropositivity, HPV infection and CIN were highly associated. Eight (73%) of 11 seropositive women with CIN had HPV detected. Both HPV infection and cervical cancer may emerge as opportunistic complications of HIV infection in populations in which HIV, HPV and cervical cancer are common.

RU486 inhibits glucocorticoid hormone-dependent oncogenesis by human papillomavirus type 16 DNA

We have previously reported (Pater et al., Nature 335, 832-835, 1988) the glucocorticoid hormone-dependent oncogenic transformation of primary baby rat kidney (BRK) cells by a combination of human papillomavirus (HPV) type 16 DNA and the activated form of the human Ha-ras-1 (ras) oncogene. In this study we provide evidence for the inhibition of such hormone-dependent transformation by the hormone antagonist, RU486. The level of inhibition was dependent on the ratio of hormone to antagonist and severe inhibition was observed at a 1:5 ratio. The effect of RU486 on the growth of HPV16-transformed cells was also studied. Severe growth inhibition and cell death occurred when cells transformed in the absence of RU486 were subsequently grown in the presence of either a 1:2.5 or 1:5 ratio of hormone to hormone antagonist. RU486 did not alter the level or electrophoretic mobility pattern of HPV16 mRNA expressed in transformed cells, when antihormone was applied either continuously or subsequent to transformation by HPV. These results indicate the importance of continuous viral gene expression for initiation and maintenance of the transformed phenotype.

Pathobiology of papillomavirus-related cervical diseases: prospects for immunodiagnosis

In recent years, the relationship between human papillomaviruses (HPV) and genital neoplasia has been explored intensively, and a molecular basis for the role of HPV in the genesis of these diseases has been convincingly demonstrated. These findings have provided justification for efforts to apply this molecular information to the early detection and possible prevention of HPV-related neoplasia. The technology of detecting viral nucleic acids in genital fluids brought with it initial hopes that it would serve to identify women at risk for having or developing precancers or cancers of the cervix. Subsequent studies, however, have demonstrated limitations of the technology for predicting future disease. Recently, molecular immunology has complemented these prior efforts, with the intent to identify serological indices of exposure to HPV and perhaps delineate individuals at risk. The molecular basis for this approach, its limitations, and future prospects for immunodiagnosis are the subject of this review.

Oral contraceptives and cervical neoplasia

Although initial studies examining the relationship of oral contraceptives to risk of cervical neoplasia were reassuring, more recent studies provide some evidence of a positive relationship, particularly for long-term usage. Results, however, are difficult to interpret, because of a variety of methodologic complexities, including potential sources of confounding and bias. Sexual behavior and Pap smear screening have been identified as important confounders, but in several well-controlled studies residual excess risks of nearly 2-fold persist for users of 5 or more years. A possible promotional effect of oral contraceptives is suggested by higher risks associated with recent usage. There also is some suggestion of a stronger effect for adenocarcinomas than for squamous cell tumors. A relationship is biologically possible, given findings of hormone receptors in cervical tissue and the fact that oral contraceptives have been found to induce cervical hyperplasia. In addition, oral contraceptives may induce proliferation of the human papillomaviruses, the leading suspect agent for cervical cancer. Although a number of lines of evidence support a relationship of oral contraceptives to cervical cancer risk, firm conclusions await the results of additional studies that specifically address some of the methodologic shortcomings of previous investigations. In particular, additional follow-up studies are needed to define the effect of oral contraceptives on the natural history of cervical lesions.

Biology of female sex hormone action in relation to contraceptive agents and neoplasia

This article will present an overview of estrogen and progestin action at a cellular level, with emphasis on points that are relevant to neoplasia. In breast, endometrium and ovary, these two classes of hormone are clearly implicated in carcinogenesis, but their involvement with cancers of the liver, cervix and other tissues is more problematic. In the latter situations, I will highlight the major points to be considered if the hormones are involved without wishing to judge whether there actually is a causal involvement.