Oral contraceptives and cervical neoplasia

Contraceptive strategies for reducing the risk of reproductive cancers

Reproductive cancers, encompassing various malignancies like endometrial, ovarian, cervical cancer, and gestational trophoblastic neoplasia, pose a significant global health burden. Understanding their patterns is vital for effective prevention and management. Contraceptives show a protective effect against some of these cancers. This clinical guidance document aims to elucidate the disease burden of reproductive cancers and the evidence supporting contraceptive methods in prevention and management. Regional disparities in incidence and mortality highlight the urgent need for targeted interventions, particularly in low-resource settings. Healthcare providers must weigh individual risk profiles and medical eligibility criteria when discussing contraceptive options. Enhanced health literacy through direct patient education is essential for leveraging low-cost behavioral interventions to mitigate reproductive cancer risks.

Pharmacodynamics of combined estrogen-progestin oral contraceptives: 4. Effects on uterine and cervical epithelia

Introduction: Steroid hormones are responsible for specific changes in the endometrium during the menstrual cycle, when they are sequentially secreted and, because of this, in the early days sequential combined oral contraceptive regimens were utilized. The same basic concept has been utilized with multi-phasic regimens, in order to produce endometrial pictures mimicking the normal cycle.Areas covered: The Endometrial effects of progestins and estrogens; combined monophasic high- (50 μg), medium- (30 μg), low- (20 μg), ultralow- (15 μg) estrogen content; sequential regimens; multiphasic combinations; treatment schedules.Cervical effects of combined high-dose and sequential combinations, including evidence for an increase in malignant lesions.Expert opinion: Overall, combined oral contraceptives (COCs) inhibit normal proliferative changes and the endometrium becomes thin, narrow, with widely spaced glands and pre-decidual changes in the stroma. During the first few cycles the progestin induces a coexistence of proliferative and secretory features; with time, the picture changes because the progestin induces a down-regulation of estrogen receptors, resulting in tortuous glands similar to those in the secretory phase, but characterized by a quiescent, atrophic glandular epithelium.In the cervical epithelium, under the influence of high-dose COCs, endocervical glands became hypersecretory and in some instances, distinctive type of atypical polypoid endocervical hyperplasia is found.

Risk factors associated with precancerous cervical lesion among women screened at Marie Stops Ethiopia, Adama town, Ethiopia 2017: a case control study

OBJECTIVE

Although cervical cancer is a preventable disease, it remains a leading cause of death among women in developing countries. In this unmatched case control design, 55 cases and 109 controls were included. The main objective of this study was to assess the risk factors of precancerous cervical lesion in Adama town.

RESULTS

A total of 164 participants were recruited in this study. Of the 109 controls, 64 (61%) and 41 (39%) of cases were using oral contraception. Women who were using oral contraception were two times at risk for developing precancerous cervical lesion than who were not using (COR = 2.059 95% CI 1.006, 4.216; AOR = 2.342). Out of 55 cases, 21 (38.2%) cases had a history STI and out of 109 controls, 24 (22.2%) controls had a history of STI. It was revealed that STI has a significant association for developing of precancerous lesion. Women who had a history of STI were two times at risk of developing precancerous cervical lesion than who had no (COR = 2.187; AOR = 2.485). It was found that initiation of sexual intercourse before the age of 15 years has 5.6 risks to develop precancerous cervical lesion (COR = 5.625 AOR = 6.703).

MDM2 polymorphism associated with the development of cervical lesions in women infected with Human papillomavirus and using of oral contraceptives

Background

The MDM2 gene is the major negative regulator of p53, a tumor suppressor protein. Single nucleotide polymorphism in promoter region of MDM2 gene leads to increased expression resulting in higher levels of MDM2 protein. This event increases the attenuation of the p53 pathway. Polymorphisms in this gene can interfere in the regulation of cellular proliferation. We evaluated whether MDM2 SNP309 (rs2278744) associated or not with the use of oral contraceptive can heighten susceptibility to development of cervical lesions in women HPV infected.

Methods

MDM2 SNP309 (rs2278744) was genotyped in a total of 287 patients using the PCR-RFLP technique. The results were analyzed by UNPHASED v.3.121 and SNPStats programs.

Results

The three groups (SIL, LSIL and HSIL) showed no significant differences in either genotype or allelic frequencies for MDM2 polymorphisms, except when HSIL was compared with LSIL (p = 0.037; OR = 1.81). Furthermore, in the analysis of contraceptives, a significant association was found between the use of contraceptives and the MDM2 variant in the development of high-grade cervical lesions for the TG genotype (p = 0.019; OR = 2.21) when HSIL was compared with control. When HSIL was compared with LSIL (p = 0.006; OR = 2.27).

Conclusion

The results of this study suggest that MDM2 SNP309 might be a good marker for assessing the progression of LSIL to HSIL. In addition, they also show that oral contraceptives alone, did not have any effect on the progression or development of cervical lesions. However, they may act synergistically with MDM2 SNP309 (rs2278744) and HPV infection in the development of cervical lesions.

Physical and functional interactions of human papillomavirus E2 protein with nuclear receptor coactivators

In addition to the human papillomavirus (HPV)-induced immortalization of epithelial cells, which usually requires integration of the viral DNA into the host cell genome, steroid hormone-activated nuclear receptors (NRs) are thought to bind to specific DNA sequences within transcriptional regulatory regions on the long control region to either increase or suppress transcription of dependent genes. In this study, our data suggest that the NR coactivator function of HPV E2 proteins might be mediated through physical and functional interactions with not only NRs but also the NR coactivators GRIP1 (glucocorticoid receptor-interacting protein 1) and Zac1 (zinc-finger protein which regulates apoptosis and cell cycle arrest 1), reciprocally regulating their transactivation activities. GRIP1 and Zac1 both were able to act synergistically with HPV E2 proteins on the E2-, androgen receptor-, and estrogen receptor-dependent transcriptional activation systems. GRIP1 and Zac1 might selectively function with HPV E2 proteins on thyroid receptor- and p53-dependent transcriptional activation, respectively. Hence, the transcriptional function of E2 might be mediated through NRs and NR coactivators to regulate E2-, NR-, and p53-dependent transcriptional activations.

Human papillomavirus E2 protein associates with nuclear receptors to stimulate nuclear receptor- and E2-dependent transcriptional activations in human cervical carcinoma cells

Steroid hormones are proposed to act with human papillomaviruses (HPVs) as cofactors in the etiology of cervical cancer. Steroid hormone-activated nuclear receptors (NRs) are thought to bind to specific DNA sequences within transcriptional regulatory regions on the HPV DNA to either increase or suppress transcription of dependent genes. HPV-induced immortalization of epithelial cells usually requires integration of the viral DNA into the host cell genome. The integration event causes disruption of the E2 gene: the E2 protein is a transcription factor that regulates expression of the E6 and E7 oncoproteins by binding to four sites within the viral long control region (LCR). Our previous study suggested that E6 and E7 oncoproteins both directly bind to some NRs and serve as their cofactors. Here, we provide several lines of evidence demonstrating that the E2 protein is an NR coactivator through its physical interaction with NRs. In our study, the NR coactivator function of HPV E2 protein in human cervical carcinoma cells was independent of the type of E2, HPV transformation and the p53 status. Our observations also provide evidence suggesting regulatory mechanisms for the LCR involving interaction between the E2 protein and NRs in HeLa cells.

Hormonal contraception in adolescents: special considerations

With the rates of unintended pregnancies in teenagers remaining high, it is crucial to present adolescents with all of the contraceptive options available to them. While barrier methods, for example, male condoms, are easily accessible and do not have adverse effects, their use must be consistent and correct with each act of intercourse. Hormonal contraception affords much better efficacy in preventing pregnancy when used with full compliance. Oral contraceptives are a popular method of contraception among adolescents and offer many non-contraceptive benefits along with the prevention of pregnancy. They have very few significant adverse effects, which are outweighed by the significant morbidity associated with teenage pregnancies, and can be used by most adolescent females. However, their minor bothersome effects do contribute to the high discontinuation rates seen. In addition, many girls find it difficult to remember to take a pill every day, leading to higher failure rates in teenagers than in adult women. The advent of long-acting, progestogen (progestin)-only methods, such as injectables and implantables, has been generally accepted by adolescents and these methods have proven to be more efficacious by avoiding the need for daily compliance. However, progestogen-only methods cause irregular bleeding and amenorrhea, which is not acceptable to many teenagers. In addition, the most widely used implant was taken off the market a few years ago and newer forms are not yet widely accessible. Other novel methods are currently available, including the transdermal patch and the vaginal ring. Both are combinations of estrogen and progestogen and have similar efficacy and adverse effect profiles to oral contraceptives. Their use may be associated with greater compliance by adolescents because they also do not require adherence to a daily regimen. However, there may be some drawbacks with these newer methods, for example, visibility of the patch and difficulty with insertion of the vaginal ring. When regular contraceptive modalities fail, emergency contraception is available. Choices include combination oral contraceptives, progestogen-only pills, mifepristone, or placement of a copper-releasing intrauterine device. These methods can be very useful for preventing pregnancy in adolescents as long as adolescents are aware of their existence and have easy access to them.

NRIP, a Novel Nuclear Receptor Interaction Protein, Enhances the Transcriptional Activity of Nuclear Receptors

Transcriptional regulation by members of the nuclear hormone receptor superfamily is a modular process requiring the mediation of distinct subclasses of coregulators. In this study, we isolated a novel WD40 repeat-containing gene, human nuclear receptor interaction protein (NRIP). We found NRIP interacts with either androgen or glucocorticoid receptors from in vitro and in vivo pulldown assays. Subsequently, transient transfection and luciferase activity assays suggested that NRIP was a ligand-dependent coactivator of steroid receptors (androgen and glucocorticoid) in distinct promoters. To further clarify the function of NRIP, we found an RNA interference-3-targeted NRIP gene sequence (5'-GATGATACAGCACGAGAAC-3') that could efficiently and specifically knock down endogenous and exogenous NRIP gene expression and that significantly diminished cell proliferation in prostate (LNCaP) and cervical (C33A) cells. Therefore, NRIP may play a role in enhancing the transcriptional activity of nuclear receptors and may be a critical target for developing therapeutic agents against nuclear receptor-mediated progression of prostate and cervical cancers.

Aberrant p16 methylation is a biomarker for tobacco exposure in cervical squamous cell carcinogenesis

OBJECTIVE

The purpose of this study was to determine the association between active tobacco exposure and aberrant p16 promoter methylation in primary cervical squamous cell cancer and high-grade squamous cervical dysplasia.

STUDY DESIGN

p16 methylation-specific polymerase chain reaction was performed on DNA that was extracted from 60 cervical cancers, 30 high-grade dysplasia specimens, and 78 normal cervical cytologic specimens. Patient data were obtained by medical record review or were collected prospectively.

RESULTS

Aberrant p16 methylation was significantly higher in squamous cell cervical cancers (61%) than in squamous high-grade dysplasia (20%) or normal cytologic specimens (7.5%). Approximately one half the women with squamous cancer and one half of the women with high-grade dysplasia were active smokers. Aberrant p16 methylation was associated with active tobacco use in patients with squamous carcinoma (odds ratio, 20.6; 95% CI, 3.6-118; P<.001) and high-grade dysplasia (odds ratio, 4.57; 95% CI, 1.63-12.78; P=.002).

CONCLUSION

Aberrant p16 methylation is associated strongly with active tobacco use in squamous cell cervical cancers and high-grade dysplasia.

Replication and interaction of herpes simplex virus and human papillomavirus in differentiating host epithelial tissue

We have investigated the interactions and consequences of superinfecting and coreplication of human papillomavirus (HPV) and herpes simplex virus (HSV) in human epithelial organotypic (raft) culture tissues. In HPV-positive tissues, HSV infection and replication induced significant cytopathic effects (CPE), but the tissues were able to recover and maintain a certain degree of tissue integrity and architecture. HPV31b not only maintained the episomal state of its genomic DNA but also maintained its genomic copy number even during times of extensive HSV-induced CPE. E2 transcripts encoded by HPV31b were undetectable even though HPV31b replication was maintained in HSV- infected raft tissues. Expression of HPV31b oncogenes (E6 and E7) was also repressed but to a lesser degree than was E2 expression. The extent of CPE induced by HSV is dependent on the magnitude of HPV replication and gene expression at the time of HSV infection. During active HSV infection, HPV maintains its genomic copy number even though genes required for its replication were repressed. These studies provide new insight into the complex interaction between two common human sexually transmitted viruses in an in vitro system, modeling their natural host tissue in vivo.

Depot-medroxyprogesterone acetate injection (Depo-Provera): a highly effective contraceptive option with proven long-term safety

Depot-medroxyprogesterone acetate (Depo-Provera(R)) is a highly effective, nondaily hormonal contraceptive option that has been available in the United States for a decade, and worldwide for 40 years. Benefits and risks of hormonal therapy are often under scrutiny; however, long-term clinical experience has established the safety of this long-acting contraceptive. This article reviews the contraceptive efficacy, potential noncontraceptive health benefits and long-term safety of with regard to risk of cardiovascular events, breast and gynecologic malignancy and osteopenia. Comparisons with other hormonal contraceptives are made as clinically appropriate. Common patient management issues, including effects on menstrual cycle, body weight and mood, are also addressed. Finally, this review provides recommendations for appropriate patient selection.

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.

Risk factors related to the development and mortality from invasive cervical cancer clinical utility and impact on prevention

The focus of this article is to explore the various risk factors related to cervical cancer and the practical context in which they can be applied. The ability to link dinical outcomes (disease presence, persistence, progression, and recurrence) with antecedent risk factors is strengthened by a new understanding of the molecular mechanisms that are responsible for malignant transformation.

Management of precursor lesions of cervical carcinoma: history, host defense, and a survey of modalities

Before the initiation of screening and treatment for cervical cancer precursors, approximately 3% to 4% of women were destined to eventually develop cervical cancer. During the last 50 years the rate of cervical cancer incidence and mortality has decreased by more than 75% primarily because of the widespread availability of cervical cytologic screening and of treatment for documented cervical precancer. Successful screening of the entire population and appropriate treatment of lesions could theoretically reduce this risk to one tenth of the risk of an unscreened population [7,28]. The relatively recent understanding of the etiology of cervical cancer precursor lesions and of the immune response to them has given new direction to management options that incorporate healthy habits and dietary measures as part of traditional ablative or excisional treatment options. As we look to the future we can expect that new markers that more specifically identify individuals at-risk for cervical precancer and cancer will be developed and take precedence in cervical screening. At the same time, treating the cause of these lesions, rather than the result, should provide less traumatic and more successful therapies. To this end, harnessing the immune system through immune response modifiers and HPV vaccines seems to be on the horizon, as do new chemopreventative approaches. Of all human cancers, only cervical cancer, once the second most common cancer among women, stands on the threshold of being virtually eliminated.

The upstream regulatory region of human papillomavirus type 31 is insensitive to glucocorticoid induction

The upstream regulatory region (URR) of various types of human papillomaviruses (HPVs) has been shown to contain functional glucocorticoid response elements (GREs), including HPV type 11 (HPV11), HPV16, and HPV18. Glucocorticoids have been demonstrated to induce the transcriptional activity of the early promoters of these HPV types. Although it has been assumed that the URR of HPV31 contains at least one GRE, no functionality has been demonstrated. We attempt to show here inducibility of the URR of HPV31 by the synthetic glucocorticoid dexamethasone (dex). By sequence analysis we identified three potential GREs in the URR of HPV31. Gel shift analysis indicated that each of these three sites has the potential to be a functional GRE. However, constructs containing the full-length URR, 5' deletions of the URR, and an internal fragment of the URR containing all three putative GREs were only weakly inducible by dex. Linker scanning mutants, whereby each potential GRE was replaced individually, in double combination, or in triple combination by a unique polylinker, had no effect on dex inducibility. Replacement of each of the three HPV31 GREs with the GRE of HPV18 failed to induce a response to dex. Placement of the HPV18 GRE into the URR of HPV31 in a region similar to its location in the HPV18 URR was also unable to result in a strong dex induction of the HPV31 URR. These data suggest that the lack of dex inducibility is due to the overall context of the HPV31 URR and may be dependent on the requirements of the major early promoter for transcriptional activation. Finally, replacement of the HPV18 GRE with each of the HPV31 GREs in HPV18 only showed weak inducibility, indicating that the three GREs of HPV31 are in fact only weak inducers of dex. Overall, these data suggest that dex responsiveness, along with oncogenic potential, may provide a possible explanation for the classification of HPV31 as an intermediate-risk virus and demonstrate the complexity of transcriptional regulation of the URR of HPV.

Does contraceptive method change the Pap smear finding?

The aim of the present study was to investigate the effect of various types of contraceptives on morphological finding of Pap smear results. Pap smear results of 7,753 fertile women who presented to 15 different family planning services in Fars Province (south of Iran) were analyzed according to their methods of contraception. The population consisted of 2241 women who used intrauterine device (IUD) as a contraceptive method (Group 1), 2521 women who were oral contraceptive (OCP) users (Group 2), and the control group, which consisted of women who used other methods of contraceptive. Comparison between the Pap smear results showed a higher number of benign cellular changes among Group 1 (22.4%) than Group 2 (19.3%), and the differences were statistically significant (p = 0.009). In addition, 80.6% women who used oral contraceptive pill (OCP) as contraceptive showed cellular changes within normal limits, while it were 77.6% for intrauterine device (IUD) users. Compared with Group 2, Group 1 had a significantly higher percentage of metaplastic cells in their Pap smear results (G1 7.4%, G2 5.8%, p < 0.05). No epithelial abnormalities were reported in Pap smears. Trichomonas vaginalis was higher in G1 than the other groups (p < 0.005), but the difference was not statistically significant for candidiasis. It may be concluded that in this population, IUD and OCP had no effect on morphological pattern of the Pap smears, but there was a significant increased rate of trichomonas infection in IUD users.

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.

Clinical breast and pelvic examination requirements for hormonal contraception: Current practice vs evidence

Clinical breast and pelvic examinations are commonly accepted practices prior to provision of hormonal contraception. Such examinations, however, may reduce access to highly effective contraceptive methods, and may therefore increase women's overall health risks. These unnecessary requirements also involve ethical considerations and unwittingly reinforce the widely held but incorrect perception that hormonal contraceptive methods are dangerous. This article reviews and summarizes the relevant medical literature and policy statements from major organizations active in the field of contraception. Consensus developed during the last decade supports a change in practice: hormonal contraception can safely be provided based on careful review of medical history and blood pressure measurement. For most women, no further evaluation is necessary. Pelvic and breast examinations and screening for cervical neoplasia and sexually transmitted infection, while important in their own right, do not provide information necessary for identifying women who should avoid hormonal contraceptives or who need further evaluation before making a decision about their use.

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.

Women's health

Symptoms reliably attributable to menopause are vasomotor symptoms and vaginal dryness. Other symptoms are not directly related to the menopause. HRT or ERT are effective in providing symptom relief and preventing disease prevalent in postmenopausal women. HRT or ERT is beneficial in women with RA. Little data concerns safety in SLE patients, but there are theoretical advantages to using HRT or ERT in women with SLE and two studies that indicate it is safe. Other forms of treatment are available to women who cannot or will not use HRT or ERT.

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.

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.

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)

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.

Risk of cervical dysplasia in users of oral contraceptives, intrauterine devices or depot-medroxyprogesterone acetate. The New Zealand Contraception and Health Study Group

Three cohorts of women aged 20-39 attending medical practitioners or family planning clinics in New Zealand for contraceptive advice were followed prospectively for five years. The three cohorts were defined by use (or at least prescription) of one of three study contraceptive methods at the time of beginning of follow-up--oral contraceptives (OC), intrauterine devices (IUD) or depot-medroxyprogesterone acetate (MPA)--and numbered 2469, 2072 and 1721 women, respectively. Follow-up was intended to be annual and included cervical smear as well as interim contraceptive and medical histories. A positive outcome (referred to here as 'dysplasia') was any degree of definite dysplasia or carcinoma of the cervix diagnosed cytologically by a central study laboratory, and confirmed by histology or analysis of DNA ploidy. In the three cohorts (OC, IUD and MPA, respectively), 12,839, 10,774 and 8,984 person-years of follow-up were accumulated and 125, 92 and 101 cases of dysplasia were confirmed. Crude annual rates of dysplasia per 1,000 person-years were approximately the same in the OC (9.6) and IUD (8.4) cohorts. Crude rates were higher in the MPA cohort (11.3 per 1,000 person-years). However, important confounding factors, principally smoking and sexual behavior, were identified with rate ratios ranging between 1 and 3 over the range of the potentially confounding variables, and multivariate analyses revealed no evidence of increased risk for the MPA cohort when these factors were taken into account. At least over the short term, there appears to be no difference in risk of cervical dysplasia between women using these three methods of contraception if differences between groups in respect to known confounding factors are taken into account.

Monthly combined injectable contraceptives and neoplasia

Monthly injectable contraceptives, containing a combination of a long-acting progestogen and an estrogen, have been used in Latin America and China for many years. While knowledge about the effects of other hormonal contraceptives on cancer risk is relevant, close analogies with monthly injectables cannot be made. The relation between use of these preparations and cancers of the breast and cervix has been examined in case-control studies, but no firm conclusions can be drawn because of limitations in sample size. Adequate studies of the influence of monthly injectable contraceptives on risk of neoplasia need to be carried out.

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.

Impact of contraception on gynecologic cancers

In considering the appropriate contraceptive method for a particular woman, the potential effect of that method on her risk of developing cancer of the breast, cervix, endometrium, or ovary is crucial. Among the most closely studied of the risk factors for gynecologic neoplasm has been the potential role of contraceptives, especially oral contraceptives, intrauterine devices, and injectable progestins. Physicians need to consider the potential impact of these agents on the disease process, therapy for the disease, future fertility, and the health of the fetus. Although much of the epidemiologic data is inconsistent and difficult to interpret, most studies find no association between oral contraceptive use and increased risk of breast cancer, except possibly in younger women (< 45 years of age) with prolonged use. Oral contraceptive use may also protect against benign breast disease. Data concerning oral contraceptive use and cervical neoplasm are confounded by several interacting variables, the most important of which is that oral contraceptive users tend to have more Papanicolaou smears than nonusers. Some studies have indicated an increased risk of two- to fourfold after 10 years of use. Oral contraceptive use provides clear protection against endometrial and ovarian cancer, an effect that persists for years after discontinuation. Less data have been collected regarding the relationship between intrauterine devices and injectable hormonal preparations and various types of cancer. No evidence suggests that the intrauterine device predisposes to the development of preneoplastic conditions of the cervix, nor to endometrial or ovarian cancer. A reliable form of contraception is indicated in women with cancer of any kind that may require chemotherapy or radiation, because these treatments can have adverse effects on the fetus, especially if given during the first trimester.

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 contraceptive use and the incidence of cervical intraepithelial neoplasia

OBJECTIVE

Our objective was to examine the relationship between oral contraceptive use and the incidence of cervical intraepithelial neoplasia.

STUDY DESIGN

In a prospective follow-up study of 6622 women participating in the Second Tromsö Study conducted in 1979 and 1980 in Tromsö, Norway, women aged 20 to 49 years answered a questionnaire regarding their smoking history, dietary habits, alcohol consumption, and oral contraceptive use. They were then followed for 10 years with data from the Pathology Registry of the University Hospital.

RESULTS

The age-adjusted incidence rate of cervical intraepithelial neoplasia was 897 per 100,000 person years among noncurrent and 1295 per 100,000 person years among current oral contraceptive users as of 1979. After adjusting for age, marital status, smoking, and frequency of alcohol intoxication the relative rate for current users was 1.5 (95% confidence interval 1.1 to 2.1), and the relative rate for past users was 1.4 (95% confidence interval 1.0 to 1.8), as compared with those who had never used oral contraceptives before 1979.

CONCLUSION

These findings support the hypothesis that the occurrence of cervical intraepithelial neoplasia is increased by oral contraceptive use.

Contraceptive steroids and the mammary gland: is there a hazard?--Insights from animal studies

The safety of synthetic steroid hormones to be used for contraception in the human female is tested in rats, beagle dogs, and (once marketing starts) in monkeys. Because early studies did not show a mammary tumor stimulating effect in the human, in contrast to findings in the dog, many objections have been raised to the use of the dog for these toxicity studies. It has been claimed that the dog is unique in its sensitivity to the mammary tumor promoting effect of progestins and that this tumorigenic effect results from progestin-induced growth hormone (GH) induction. A thorough review of the literature does not support these claims. Tumor stimulatory effects of progesterone or synthetic progestins can be observed under some conditions in rodents as well as in cats and monkeys. In addition, recent evidence suggests a role for progesterone in mammary tumorigenesis in the human, and contraceptive steroids may also not be completely without risk. While the suggested role for GH in dog mammary tumorigenesis is far from proven, such a role cannot be excluded in the other species. Whether tumor stimulatory effects of sex steroids are based upon induction of proliferation in target cells or upon genotoxic effects or both is not yet certain.