On the epidemiology of oral contraceptives and disease

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.

Reevaluating the Role of Progesterone in Ovarian Cancer: Is Progesterone Always Protective?

Ovarian cancer (OC) represents a collection of rare but lethal gynecologic cancers where the difficulty of early detection due to an often-subtle range of abdominal symptoms contributes to high fatality rates. With the exception of BRCA1/2 mutation carriers, OC most often manifests as a post-menopausal disease, a time in which the ovaries regress and circulating reproductive hormones diminish. Progesterone is thought to be a "protective" hormone that counters the proliferative actions of estrogen, as can be observed in the uterus or breast. Like other steroid hormone receptor family members, the transcriptional activity of the nuclear progesterone receptor (nPR) may be ligand dependent or independent and is fully integrated with other ubiquitous cell signaling pathways often altered in cancers. Emerging evidence in OC models challenges the singular protective role of progesterone/nPR. Herein, we integrate the historical perspective of progesterone on OC development and progression with exciting new research findings and critical interpretations to help paint a broader picture of the role of progesterone and nPR signaling in OC. We hope to alleviate some of the controversy around the role of progesterone and give insight into the importance of nPR actions in disease progression. A new perspective on the role of progesterone and nPR signaling integration will raise awareness to the complexity of nPRs and nPR-driven gene regulation in OC, help to reveal novel biomarkers, and lend critical knowledge for the development of better therapeutic strategies.

Some Further Consideration on the Role of Oral Contraceptives in Breast Carcinogenesis

Available evidence concerning oral contraceptives and their potential interaction with reproductive history on breast cancer risk Is reviewed. The relative risks in 15 out of 15 studies were above unity among younger women (i.e., below age 35 and perhaps up to 45) for long-term oral contraceptive use, although apparent heterogeneities emerged in the risk estimates. The overall evidence is reassuring in subsequent age groups, whereas the modifying effects or interactions between oral contraceptives, reproductive factors and breast cancer risk are still largely undefined. Thus we suggest that, besides chance and bias, the apparent discrepancies between various studies should be considered within the framework of the complex time- and age-effects of hormone-related risk factors on breast carcinogenesis.

The Influence of Female Hormones on Malignant Melanoma

Several lines of biological evidence have suggested a relationship between the behaviour of melanocytes and cutaneous malignant melanoma (CMM) and the action of female hormones. The present overview, however, indicates that the effect of reproductive, menstrual and hormonal factors, including oral contraceptives, on onset and outcome of CMM must be very weak, if any. The only consistent findings which may suggest a role of female hormones on CMM seem to be: 1) a different distribution by anatomic site in men and women, and 2) a more favorable outcome of CMM in women as compared to men. Neither of them, however, necessarily implies a direct effect of female hormones on CMM.

Impact and mechanistic role of oral contraceptive pills on the number and epithelial type of ovarian cortical inclusion cysts; a clinicopathology and immunohistochemical study

Background

Ovarian epithelial cancers are among the most lethal women's cancers. There is no doubt about the preventive role of oral contraceptive pills (OCPs) in development of ovarian cancers. But, there are limited numbers of studies to address the effect of these agents on the number of cortical inclusion cysts (CICs), their epithelial type and suppression of the metaplastic phenomenon by these pills. The aim of this study was to clarify the role of these agents in the prevention of these cyst formation and tubal metaplasia and also examine the mesenchymal-epithelial transition theory in this context by immunohistochemical methods.

Methods

The representative section(s) of ovarian cortex from a total number of 201 consecutive total abdominal hysterectomy with bilateral or unilateral salpingo-oophorectomy specimens were examined for mean number of CICs and their epithelial type between two groups of the patients. Group A included the patients who were on oral contraceptive pills for more than 5 years. All of the subjects with other contraceptive methods or a history of less than 5 years contraceptive pills usage were stratified in group B. Sections from 20 cases in which more than five inclusion cysts were found, were selected for IHC staining with calretinine and PAX8 as markers for mesothelium and mullerian epithelium respectively.

Results

The mean age of the patients was 51.67 years with no significant differences between two groups. The mean number of cysts were 1.27 and 3.23 in group A and B respectively (P =0.0001). Similarly the mean number of CICs, lined by tubal epithelium, was significantly different between two groups (0.65 vs 2.65, P =0.0001). In IHC staining 123 out of 150 CICs (82 %) were PAX+ while only 7 CICs (4.8 %) showed positive reaction for calretinin irrespective of type of epithelium.

Conclusion

Our findings showed that the use of OCP for more than five years in women, significantly prevents development of cortical inclusion cysts in the ovaries which lined by tubal (PAX8 positive) type epithelium. These findings may explain the alternative mechanism of oral contraceptive pills or long time use of progesterone in suppression of tubal type overgrowth and subsequently prevention of ovarian epithelial cancers.

Sensitivity and specificity of the Streptococcus pneumoniae urinary antigen test for unconcentrated urine from adult patients with pneumonia: a meta-analysis

Studies on the sensitivity and specificity of the Binax Now Streptococcus pneumonia urinary antigen test (index test) show considerable variance of results. Those written in English provided sufficient original data to evaluate the sensitivity and specificity of the index test using unconcentrated urine to identify S. pneumoniae infection in adults with pneumonia. Reference tests were conducted with at least one culture and/or smear. We estimated sensitivity and two specificities. One was the specificity evaluated using only patients with pneumonia of identified other aetiologies ('specificity (other)'). The other was the specificity evaluated based on both patients with pneumonia of unknown aetiology and those with pneumonia of other aetiologies ('specificity (unknown and other)') using a fixed model for meta-analysis. We found 10 articles involving 2315 patients. The analysis of 10 studies involving 399 patients yielded a pooled sensitivity of 0.75 (95% confidence interval: 0.71-0.79) without heterogeneity or publication bias. The analysis of six studies involving 258 patients yielded a pooled specificity (other) of 0.95 (95% confidence interval: 0.92-0.98) without no heterogeneity or publication bias. We attempted to conduct a meta-analysis with the 10 studies involving 1916 patients to estimate specificity (unknown and other), but it remained unclear due to moderate heterogeneity and possible publication bias. In our meta-analysis, sensitivity of the index test was moderate and specificity (other) was high; however, the specificity (unknown and other) remained unclear.

The versatility of multi-state models for the analysis of longitudinal data with unobservable features

Multi-state models provide a convenient statistical framework for a wide variety of medical applications characterized by multiple events and longitudinal data. We illustrate this through four examples. The potential value of the incorporation of unobserved or partially observed states is highlighted. In addition, joint modelling of multiple processes is illustrated with application to potentially informative loss to follow-up, mis-measured or missclassified data and causal inference.

50 years of "The Pill": celebrating a golden anniversary

The past 50 years have seen great advances in combined oral contraceptives (COCs) that have resulted in reduced risks of adverse events and improved cycle control. The most important changes in COCs over time include repeated lowering of the estrogen dose, development of new progestogens, and the reduction or elimination of the pill-free interval. Most recently, formulations that deliver estradiol in lieu of ethinylestradiol have been introduced. The advantages of COCs generally far outweigh the disadvantages. Current options in oral contraception include a wide spectrum of products that enable clinicians to choose the most appropriate formulation for individual women. This article summarises the advances in oral contraceptives over time and describes the most current clinical data regarding the use of COCs.

Meta-analysis of clinical studies of the purported deleterious effects of "old" (versus "fresh") red blood cells: are we at equipoise?

BACKGROUND

A meta-analysis examined whether the available data support an adequate suspicion that transfusion of old red blood cells (RBCs) is associated with increased mortality, organ failure, infection, prolonged mechanical ventilation, and prolonged stay in the hospital or the intensive care unit. Such suspicion is required for intentionally exposing patients enrolled in randomized controlled trials (RCTs) to the known or probable--but rare--risks of old RBCs, to document (and prevent) purported common adverse effects of old RBCs.

STUDY DESIGN AND METHODS

Observational studies presenting adjusted results were eligible for analysis if the adequacy of the adjustment for confounding factors could be assessed. Three RCTs and 24 observational studies were retrieved. Medically and statistically homogeneous studies were integrated by fixed-effects methods. Otherwise homogeneous studies conducted in different clinical settings were integrated by random-effects methods.

RESULTS

Based on "as-treated" analysis, transfusion of old RBCs was associated with a significant reduction in mortality (summary odds ratio, 0.38; 95% confidence interval, 0.14-0.99; p < 0.05) across two small RCTs. Integration of adjusted findings on the same outcome, from observational studies conducted in the same setting, produced summary results that were either negative (in six analyses) or impossible to evaluate owing to uncontrolled confounding by the number of transfused RBCs (in two analyses).

CONCLUSION

The available data do not support an adequate suspicion that old RBCs may be associated with common adverse morbidity and/or mortality outcomes, so as to justify exposing experimental subjects to the other known or probable--but rare--risks of old RBCs.

Prognostic significance of FTO genotype in the development of obesity in Japanese: the J-SHIPP study

OBJECTIVE

Susceptibility of fat mass and obesity-associated (FTO) gene polymorphisms to obesity has been reported in various populations. Polymorphisms in the melanocortin 4 receptor (MC4R) gene were recently explored as another susceptible locus. However, prognostic significance of these genetic variations has not been fully elucidated. Here, we investigated the involvement of FTO rs9939609 and MC4R rs17782313 polymorphisms in the development of obesity. Association with type 2 diabetes mellitus (T2DM) was also investigated.

SUBJECTS

We analyzed 2806 community-dwelling middle-aged to elderly subjects (61+/-14 years). Clinical parameters were obtained from the subjects' personal health records, evaluated at their annual medical check-up.

RESULTS

FTO genotype was significantly associated with current body mass index (BMI; TT 23.2+/-3.2, TA 23.7+/-3.2, AA 24.4+/-3.2 kg m(-2), P=2.5 x 10(-6)) and frequency of obesity (26.6, 32.0, 43.0% respectively, P=2.0 x 10(-4)). Age- and sex-adjusted odds ratio for obesity was 1.30 (P=0.004) in TA and 2.07 (P=0.002) in AA genotype. During the 9.4 years comprising the follow-up period, 214 new cases of obesity were diagnosed among 1718 subjects whose retrospective data were available. A allele frequency of the FTO genotype was significantly higher in subjects who developed obesity (22.2, 15.8%, P=0.001), Age-, sex- and initial BMI-adjusted odds ratio for the development of obesity was 1.46 (95% confidence interval, 1.04-2.04) (P=0.031). However, association studies and meta-analysis of T2DM did not actively support the involvement of FTO genotype. No significant differences were observed between the MC4R genotype and BMI (P=0.015), and the frequency of obesity (P=0.284).

CONCLUSION

FTO genotype is an independent risk factor for future development of obesity.

Non-contraceptive benefits of oral contraceptives

BACKGROUND

There is increasing awareness of the opportunity that many contraceptive interventions may provide for additional health benefits. However, treatment of medical problems with oral contraceptives (OCs) is often an 'off-label' practice.

OBJECTIVE

The aim of this review is to summarize available data on non-contraceptive benefits of OCs.

METHODS

Review of the literature.

RESULTS

OCs have been shown to reduce the risk of ovarian, endometrial, and colorectal cancer. It has been suggested that OCs may be used in treatment of endometriosis, menorrhagia, and uterine leiomyomas. Pelvic inflammatory disease, dysmenorrhea, premenstrual syndrome, and acne have been shown to improve under OCs.

CONCLUSION

OCs are important for global and female health. Besides contraception, non-contraceptive effects of OCs are evidence based, well established, and commonly used in clinical practice.

Physical activity and endometrial cancer risk, a systematic review of current evidence

OBJECTIVE

To assess the epidemiologic evidence for the association between physical activity and endometrial cancer risk, taking into account the methodologic quality of each study.

DESIGN

Systematic review, best evidence synthesis.

DATA SOURCES

Studies were identified through a systematic review of literature available on PubMed through December 2006.

REVIEW METHODS

We included cohort and case-control studies that assessed total and/or leisure time and/or occupational activities in relation to the incidence of endometrial cancer. The methodologic quality of the studies was assessed with a comprehensive scoring system.

RESULTS

The included cohort (n = 7) and case-control (n = 13) studies consistently show that physical activity is associated with a decreased risk of endometrial cancer. The best evidence synthesis showed that the majority (80%) of 10 high-quality studies found risk reductions of >20%. Pooling of seven high-quality cohort studies that measured total, leisure time, or occupational activity showed a significantly decreased risk of endometrial cancer (summary estimate: OR, 0.77; 95% CI, 0.70-0.85) for the most active women. Case control studies with relatively unfavorable quality scores reported divergent risk estimates, between 2-fold decreased and 2-fold increased risk. Effect modification by body mass index or menopausal status was not consistently observed. Evidence for an effect of physical activity during childhood or adolescence was limited.

CONCLUSIONS

Physical activity seems to be associated with a reduction in the risk of endometrial cancer, which is independent of body weight. Further studies, preferably prospective cohort studies, are needed to determine the magnitude of the risk reduction and to assess which aspects of physical activity contribute most strongly to the reduced risk and in which period of life physical activity is most effective.

Pharmacokinetics of chlormadinone acetate following single and multiple oral dosing of chlormadinone acetate (2 mg) and ethinylestradiol (0.03 mg) and elimination and clearance of a single dose of radiolabeled chlormadinone acetate

BACKGROUND

Published data on pharmacokinetic parameters for chlormadinone acetate (CMA) are in part contradictory, especially with regard to terminal half-life (t(1/2,z)).

MATERIALS AND METHODS

Single and multiple doses of CMA (2 mg) and ethinylestradiol (EE; 0.03 mg) were administered to healthy female volunteers for six menstrual cycles. Plasma concentrations of CMA and EE were determined by gas chromatography-mass spectrometry. Single-dose and steady-state pharmacokinetic parameters were calculated. In a separate study, healthy female volunteers were given a single 2-mg dose of radiolabeled CMA. Concentrations of radioactivity in fecal and urine samples were determined via liquid scintillation. Excretion of total radioactivity was calculated as percentage of administered dose.

RESULTS

Eighteen women completed the repeated-dose study. Peak plasma concentrations for CMA and EE were reached within 1 and 2 h after taking the study drug. Peak plasma concentrations of CMA were approximately 1600 pg/mL after single-dose administration and 2000 pg/mL after multiple dosing. CMA and EE showed linear pharmacokinetics throughout six cycles, with constant trough values of approximately 400-500 pg/mL for CMA and 20-40 pg/mL for EE. Mass balance factors were 1.2-1.4 for CMA and 1.6-1.7 for EE, and accumulation factors were 1.7-2 for CMA and 1.7-1.8 for EE. Mean t(1/2,z) of CMA was approximately 25 h after single dosing and 36-39 h at steady state. In the excretion balance study, mean dose of CMA recovered was 87.3+/-6.4%, with urinary and fecal excretion accounting for 45% and 42%, respectively.

CONCLUSIONS

The pharmacokinetics of CMA and EE is linear after multiple dosing and remains stable during long-term administration, once steady state is reached. The t(1/2,z) of CMA was 36-39 h after multiple dosing, which is considerably shorter than the 80 h often quoted in the literature.

Screening for familial ovarian cancer-management and outcome of women with moderate to high risk of developing ovarian cancer

Five percent to ten percent of ovarian cancers are hereditary. Individual genetic risk of developing ovarian malignancy is discussed in women. Currently, prophylactic surgery is advised to women with a moderate to high risk of developing ovarian cancer. Workload and outcome of the multidisciplinary familial ovarian screening clinic in South Wales were assessed. This was an observational study of 145 women registered with the Familial Ovarian Screening Clinic between January 1998 and December 2003. The data were retrieved from the medical notes. Yearly follow-ups were investigated with a transvaginal scan and CA125 level. Post-surgery women were followed up with yearly CA125 estimations: 46.9% fell into moderate-risk and 50.3% into high-risk category. The median age was 42 (SD 10.4), 71.7% were pre menopausal, and 10.3% had a personal history of breast cancer and 1.4% colon cancer. Whereas 36.5% opted for surgery, the remaining women (but two) opted for annual follow-up. Histology of the women who had surgery showed three cases of malignancies (fallopian tube carcinoma, atypical ovarian epithelial cells, and metastatic breast cancer). Seven women developed breast cancer during the observation period. The follow-up period is too short to come to a final conclusion as to the benefits of yearly screening in this group of women. In our series, a significant number of patients developed malignancies, despite prophylactic surgery.

Malignant Melanoma in Pregnancy

This article provides a concise overview of issues relating to melanoma and pregnancy, including pregnancy-associated risk and prognosis, and briefly summarizes results from relevant reports that have been published in recent years. The bulk of evidence amassed over the past half century suggests that pregnancy does not significantly affect the risk of developing malignant melanoma. Further, pregnancy does not seem adversely to influence overall survival from the disease. Most studies found no difference in overall survival between pregnant and nonpregnant women with melanoma. Recent reports from large-scale, population-based studies support these conclusions.

Ovarian neoplasms in patients with colorectal cancer: understanding the role of prophylactic oophorectomy

Although the role of prophylactic oophorectomy is currently under debate and not well defined, it is of increasing and considerable relevance, especially in premenopausal women, particularly those with identifiable hereditary cancer syndromes. Patients with colorectal cancer with ovarian metastases are often symptomatic, require surgery, and have poor survival. Prophylactic oophorectomy abolishes the increased risk of primary ovarian cancer in these patients, resects synchronous metastases, and prevents development of metachronous ovarian metastases. Prophylactic oophorectomy trials, mostly conducted in postmenopausal women, have not shown survival advantage. In patients with ovarian metastases of colorectal cancer, maximal cytoreductive surgery followed by adjuvant therapy employing newer chemotherapeutic agents, whole abdominal irradiation with chemosensitization, or hyperthermic intraperitoneal chemotherapy may improve outcomes in selected patients.

White blood cell-containing allogeneic blood transfusion, postoperative infection and mortality: a meta-analysis of observational 'before-and-after' studies

BACKGROUND AND OBJECTIVES

An association of white blood cell (WBC) reduction with decreased mortality was reported by one observational, before-and-after study. A meta-analysis was undertaken to examine whether this finding is supported by all the evidence currently available from before-and-after studies, and whether these studies support an association of WBC reduction with a decreased risk of postoperative infection.

MATERIALS AND METHODS

Observational, before-and-after studies were retrieved that reported on postoperative infection and/or mortality between January 1997 and June 2003. Six studies met the criteria for meta-analysis. Unadjusted summary odds ratios (ORs) of postoperative infection or mortality in patients transfused after (compared with before) WBC reduction were calculated across the studies if the hypothesis of homogeneity was not rejected. Adjusted summary ORs were calculated across three studies that had reported multivariate analyses.

RESULTS

There was an unadjusted association of WBC reduction with a decreased risk of postoperative infection [summary OR = 0.93; 95% confidence interval (95% CI), 0.88-0.99; P < 0.01] that did not persist following adjustment for confounding factors (summary OR = 0.94; 95% CI, 0.85-1.04; P > 0.05). There was neither an unadjusted nor an adjusted association of WBC reduction with decreased mortality (summary OR = 0.94; 95% CI, 0.71-1.23; P > 0.05; and OR = 0.92; 95% CI, 0.80-1.05; P > 0.05, respectively).

CONCLUSIONS

An association of WBC reduction with decreased mortality was not detected across the results available from all before-and-after studies. An unadjusted association of WBC reduction with a decreased risk of postoperative infection exists, but this was not detected across the three studies that reported multivariate analyses.

IGF-I and breast cancer: A meta-analysis

IGFs are peptide hormones involved in the regulation of cell proliferation, differentiation and apoptosis. IGFs are regulated by endocrine and paracrine mechanisms; however, their action in tissue is determined by circulating levels and local production of IGFs and IGF-binding proteins (IGFBPs). Some, but not all, epidemiologic studies have associated high circulating levels of IGF-I with increased risk of breast cancer among premenopausal women. To evaluate the overall association of IGF-I and IGFBP-3 levels with breast cancer risk, we performed a meta-analysis on 16 publications of epidemiologic and clinical studies. Analyses were performed for all women as well as for pre- and postmenopausal women separately. Hedges' standardized mean differences (HSMDs) and odds ratios (ORs) were used to estimate the effect of IGF-I and IGFBP-3. Data analysis showed that circulating levels of IGF-I were not significantly higher in breast cancer patients than in controls for all women and for the postmenopausal group (HSMD = 0.024 and 0.035, respectively; p > 0.40) but were significantly higher (HSMD = 0.170, p < 0.001) for the premenopausal group. ORs for breast cancer risk were 1.05 (95% CI 0.94-1.17), 0.93 (95% CI 0.80-1.10) and 1.39 (95% CI 1.16-1.66). The HSMD of IGFBP-3 was 0.18 (p < 0.001), and the OR for breast cancer was 1.42 (95% CI 1.15-1.74) for premenopausal women. Our results support the suggested association between high IGF-I and IGFBP-3 levels and increased risk of breast cancer in premenopausal women.

A pooled analysis of 10 case-control studies of melanoma and oral contraceptive use

Data regarding the effects of oral contraceptive use on women's risk of melanoma have been difficult to resolve. We undertook a pooled analysis of all case-control studies of melanoma in women completed as of July 1994 for which electronic data were available on oral contraceptive use along with other melanoma risk factors such as hair colour, sun sensitivity, family history of melanoma and sun exposure. Using the original data from each investigation (a total of 2391 cases and 3199 controls), we combined the study-specific odds ratios and standard errors to obtain a pooled estimate that incorporates inter-study heterogeneity. Overall, we observed no excess risk associated with oral contraceptive use for 1 year or longer compared to never use or use for less than 1 year (pooled odds ratio (pOR)=0.86; 95% CI=0.74-1.01), and there was no evidence of heterogeneity between studies. We found no relation between melanoma incidence and duration of oral contraceptive use, age began, year of use, years since first use or last use, or specifically current oral contraceptive use. In aggregate, our findings do not suggest a major role of oral contraceptive use on women's risk of melanoma.

Insulin-like growth factor-I and prostate cancer: a meta-analysis

Some, but not all, epidemiological found have shown that high circulating levels of insulin-like growth factor-I (IGF-I) are associated with an increased risk of prostate cancer. We performed a meta-analysis on all the studies reported so far to evaluate this association. In our Medline search, 14 case-control studies were identified. A standard protocol abstracted information for each study. Hedges' standardized mean difference (HSMD) and odds ratio (OR) were used to estimate the effect of IGF-I and IGF-binding proteins (IGFBP-3). The combined data showed that circulating levels of IGF-I were significantly higher in prostate cancer patients (HSMD = 0.194). The OR for prostate cancer was 1.47 (95% confidence interval (CI) 1.23-1.77) among men with high IGF-I compared to those with low IGF-I. The OR was 1.26 (95% CI 1.03-1.54) for IGFBP-3. Circulating levels of IGF-I and IGFBP-3 are likely to be higher in prostate cancer patients than in the controls. These findings support the suggestion that high IGF-I and IGFBP-3 are associated with an increased risk of prostate 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.

Occlusive vascular diseases in oral contraceptive users. Epidemiology, pathology and mechanisms

Despite being an unprecedented departure from normal physiology, the combined oral contraceptive is not only highly effective, but it also has a remarkably good safety record. Concerns over safety persist, though, particularly with regard to venous thromboembolism (VTE), stroke and myocardial infarction (MI). Epidemiological studies consistently show an increase in risk of VTE, but the results are more contentious with regard to arterial diseases. Despite 40 years of research, the mechanisms behind these adverse effects are not understood. In this review, we integrate information from published studies of the epidemiology and pathology of the occlusive vascular diseases and their risk factors to identify likely explanations for pathogenesis in oral contraceptive users. Oral contraceptives induce both prothrombotic and fibrinolytic changes in haemostatic factors and an imbalance in haemostasis is likely to be important in oral contraceptive-induced VTE. The complexity of the changes involved and the difficulty of ascribing clinical significance has meant that uncertainty persists. A seriously under-researched area concerns vascular changes in oral contraceptive users. Histologically, endothelial and intimal proliferation have been identified in women exposed to high plasma estrogen concentrations and these lesions are associated with thrombotic occlusion. Other structural changes may result in increased vascular permeability, loss of vascular tone and venous stasis. With regard to arterial disease risk, epidemiological information relating to dose effects and joint effects with other risk factors, and studies of pathology and changes in risk factors, suggests that oral contraceptive use per se does not cause arterial disease. It can, nevertheless, synergise very powerfully with subclinical endothelial damage to promote arterial occlusion. Accordingly, the prothrombotic effects of the oral contraceptive estrogen intervene in a cycle of endothelial damage and repair which would otherwise remain clinically silent or would ultimately progress - in, for example, the presence of cigarette smoking or hypertension - to atherosclerosis. Future work in this area should focus on modification of the effects of established risk factors by oral contraceptive use rather than modification of the supposed risk of oral contraceptive use by established risk factors. Attempts to understand vascular occlusion in oral contraceptive users in terms of the general features of VTE or with reference to atherosclerosis may be limiting, and future work needs to acknowledge that such occlusions may have unique features. Unequivocal identification of the mechanisms involved would contribute considerably to the alleviation of fears over vascular disease and to the development of even safer formulations.

Update on cancer control in women

The global cancer burden in women appears to have stabilized according to the most recent estimates available although the distribution of cancer types appears to be changing with a sharp contrast between the increase in the absolute numbers of breast cancers and a decline in cervix cancers. Prospects for cancer control in women appear to be good within our current knowledge and deserve close attention. Rates of lung cancer in women are increasing substantially in many countries and seem set to overtake breast cancer as the commonest form of cancer death in women in many parts of the world. These changes are due to the effects of cigarette smoking, a habit which women widely embraced during the second half of the last century. The high levels of smoking currently in young women, which have yet to have their full impact on death rates, constitute an important hazard not only for future cancer risks but for several other important causes of death. There is strong and consistent evidence that increased consumption levels of fruit and vegetables is associated with reduced risks of many common forms of cancer including breast cancer. Although the breast is the commonest form of cancer in women in most western countries, the etiology of this disease remains elusive and preventable causes remain to be identified. Endogenous hormones also appear to have a role in cancer risk in women: oral contraceptives seem to increase slightly the risk of breast cancer in users in the use and in the immediate post-use period, but 10 years after cessation the risk again returns to that of never users. Oral contraceptive usage also appears to be protective against ovarian and endometrial cancer. The use of hormonal replacement therapy (HRT) appears to increase the risk of endometrial cancer and a positive association with breast cancer risk appears to exist. Within our current knowledge of the epidemiology of cancer in women, the most important preventive strategies would appear to be the prevention of cigarette smoking and increased dietary intake of vegetables and fruits. Screening has also shown to be effective in reducing incidence and mortality of cervix cancer and mortality from breast cancer. Although more work is needed, it is becoming clear that there could be an important role of HPV testing to further enhance cervix cancer screening. There are important variations in survival from a variety of cancers which are due to factors unrelated to the tumor behavior and that there are significant variations in survival from cancer. Reduction of these gaps could lead to a reduction in cancer mortality and contribute towards increased prospects for cancer control in women.

The pill and cancer

The relation between oral contraceptives (OC) and cancer risk has been investigated extensively, mainly with reference to breast, female genital tract, liver cancer and cutaneous malignant melanoma, and will be summarized below. There is also some suggestion that OC use is related to other neoplasms, including a reduced risk of colorectal cancer among OC users, but the issue is still controversial and too preliminary to provide indications for informed contraception choice.

Progress in gynecologic cancer detection and treatment

Slow but steady progress has been made in the earlier diagnosis and better treatment of gynecological cancers, particularly over the last 50 years. Cervical cytology screening programs, where implemented, have led to a remarkable reduction in both the incidence and mortality from clinically invasive cervical cancer. This relatively simple technology has been truly one of the major success stories of modern medicine, but unfortunately this technique has not been uniformly applied to all women in the world, particularly to women in developing countries. New research into cervical cancer etiology, the role of HPV, and the development of vaccines against this virus offer a great hope particularly for developing countries. In addition, the combination of radiotherapy and chemotherapy has resulted in a marked improvement in outcome results for women with advanced cervical cancer. Ovarian cancer has seen the development of effective chemotherapy strategies for this disease. Currently this disease remains one of the major scourges in industrialized countries but the continued evolution of knowledge with regard to optimum sequencing of chemotherapeutic agents and surgery offers the prospect for better outcomes, less morbidity and a better quality of life. Ongoing research into the development of newer chemotherapeutic agents and a better understanding of the actual mechanisms regarding the efficacy of chemotherapy and drug resistance offers great promise for the future. Endoscopic surgery for staging and also for therapy shows promise for improved quality of life as well as outcomes for patients in the future and offers the challenge of trying to make this technology readily available to all women in the world. As we gain a better understanding of the molecular basis of disease and health we will truly be able to intervene in a preventive mode in the new millennium.

Endometrial histology during use of a low-dose estrogen-desogestrel oral contraceptive with a reduced hormone-free interval

The object of the study was to determine the effect of a new low-dose ethinyl estradiol-desogestrel oral contraceptive on endometrial histology. The oral contraceptive regimen contained fixed doses of ethinyl estradiol (20 micrograms) and desogestrel (150 micrograms) for days 1-21, placebo on days 22 and 23, and ethinyl estradiol alone (10 micrograms) on days 24-28. Endometrial histology was assessed in tissue samples obtained during treatment cycles 13 and 14. All endometrial samples were sent to a central laboratory for processing and evaluation. No endometrial hyperplasia or metaplasia was found in the endometrial biopsy specimens obtained during cycles 13 and 14 in a subset of 12 women participating in a multicenter efficacy and safety study. These results suggest that this oral contraceptive regimen, which includes 5 days of unopposed ethinyl estradiol, is not associated with endometrial hyperplasia or metaplasia. The endometrial histologic findings observed in this study were similar to those observed during the use of 21-day combination oral contraceptive regimens.

Prophylactic oophorectomy: a continuing controversy

Prophylactic oophorectomy remains a controversial issue among gynecological surgeons. A woman's history of hereditary ovarian cancer syndrome is currently considered the most important indication for prophylactic oophorectomy. This is because of the high risk of ovarian cancer developing in these women and the poor prognosis that is generally associated with ovarian cancer. The purpose of prophylactic oophorectomy in women with no family history of hereditary ovarian cancer syndrome who present for hysterectomy because of other gynecological indications is, however, less clear. The attitude of the patients toward removal of normal ovaries deserves special consideration when counseling for prophylactic oophorectomy in this group of women. Knowledge about the risk of ovarian cancer in the conserved ovaries, cancer phobia, possible psychological effects of prophylactic oophorectomy, and the need for long-term hormone replacement therapy if prophylactic oophorectomy is carried out, are all important considerations in the counseling process.

Oral contraceptive use and benign gynecologic conditions. A review

The following review considers the main epidemiologic data on oral contraceptives (OC) and the risk of major benign gynecologic diseases. Earlier studies investigating the relationship between OC use and functional ovarian cysts indicated that the use of high-dose combination OC have a protective effect, whereas low-dose monophasic or multiphasic pills have little or no effect. With regard to seromucinous cysts, the scanty data available are consistent with the notion of some protection of OC in current but not in former users, although possible effects of diagnostic and selection bias should be considered. Published data on the relationship between fibroids and OC appear too scattered to allow a precise quantification of risk. In any case, any relationship is moderate and, hence, of limited clinical and public health relevance. The data on OC and benign gynecologic conditions are reassuring in their absence of any consistent excess risk.

Tobacco smoking and gastric cancer: review and meta-analysis

Although declining, gastric cancer (GC) is estimated to be second in frequency worldwide. Major causes appear to be environmental rather than genetic. A relationship has been suggested between tobacco smoking and GC. A number of epidemiological studies have been performed dealing with this question. All the cohort studies showed a significantly increased risk of GC of the order of 1.5-2.5 for cigarette smokers. Evidence from case-control studies is less consistent. We have carried out a meta-analysis on the 40 studies providing a quantitative estimate of the association between GC risk and tobacco smoking. Results suggest a risk of stomach cancer among smokers of the order of 1.5-1.6 as compared to non-smokers. The summary relative risk was higher in men (1.59) than in women (1.11). Several studies examined the dose-response relationship which existed in 4 cohort studies and 6 case-control studies. We estimated the number of GC cases attributable to tobacco smoking occurring worldwide: in total, over 80,000 cases of GC (11% of all estimated cases) may be attributed to tobacco smoking each year. This figure is larger than that estimated for other cancers for which association with tobacco smoking is clearly established, such as pancreatic and renal cancers.

Risk of spontaneous abortion in women occupationally exposed to anaesthetic gases: a meta-analysis

OBJECTIVES

To determine the association between maternal occupational exposure to anaesthetic gases and risk of spontaneous abortion.

METHODS

A meta-analysis was performed of published epidemiological studies identified from literature reviews, unsystematic perusal of reference lists of relevant publications, and two Medline searches (1984-92, keywords: anaesthetic gases; anaesthetics; anaesthetics, local; operating rooms; operating room nursing; pregnancy; abortion; 1985-92, keywords: anaesthetics; adverse effects; occupational exposure; anaesthesia, inhalation; operating room nursing; pregnancy; abortion). All peer reviewed studies were retained. Student theses were excluded, as were conference abstracts, unpublished material, and two studies in which data on paternal and maternal occupational exposures were pooled. The relative risk of spontaneous abortion was estimated.

RESULTS

One study found no increase in risk of abortion when gases were scavenged or when the exposure to unscavenged gases was low. None of the studies included ambient gas sampling. 24 comparisons between exposed and unexposed women, obtained from 19 reports, were included. The overall relative risk was 1.48 (95% confidence interval (95% CI), 1.4 to 1.58). To test whether this result was influenced by the quality of the studies, the validity of the reviewed papers was rated on the basis of three criteria: appropriateness of the unexposed comparison group, control for non-occupational confounding variables, and response rate. The estimate of risk increased to 1.9 (95% CI, 1.72 to 2.09) when analysis was restricted to the six comparisons which were rated the most rigorous.

CONCLUSIONS

Epidemiological studies based on data obtained in the prescavenging era indicate an increased risk of spontaneous abortion. The estimated increased risk was not diminished but rather increased by exclusion of the more methodologically flawed studies.

Oral contraceptives and cancer. A review of the evidence

The following review considers epidemiological data published from 1990 onwards on oral contraceptives (OCs) and the risk of cancers of the breast, cervix uteri, endometrium, ovary, liver and skin. In several studies, breast cancer risk was seen to be elevated among women who were current users of an OC, or had recently stopped using an OC, whereas there was no residual risk 5 or more years after stopping OC use. No interaction was observed between type of OC, or with any recognised risk factor for breast cancer, or time-factor, except for some potential excess risk for women who started OC use at a young age. Most studies have confirmed that OCs moderately increase the risk of cervical cancer, particularly in human papilloma virus (HPV)-positive women, thus suggesting that OCs may act as a promoter for HPV-induced carcinogenesis. Recent epidemiological studies have confirmed that combined OCs provide substantial protection against endometrial and ovarian cancers, and results suggest that such protection is long-lasting, and may persist for 15 years or more after stopping OC use. Most case-control studies have shown a relationship between OC use and hepatocellular carcinoma. However, data from cohort studies or analysis of vital statistics indicate that the public health impact of such an association is modest, if not negligible. No association was observed between combined OC use and the incidence of skin melanoma, or any other common skin neoplasm. In terms of clinical and public health implications, the most relevant points regarding OC use are: (i) recent data confirm that OCs confer presistent protection against ovarian cancer; and (ii) any increased risk of breast cancer in OC users is moderate and is restricted to current/recent users. This is reassuring for younger women, whose baseline risk of this disease is extremely low.

Recent trends in incidence of and mortality from breast, ovarian and endometrial cancers in England and Wales and their relation to changing fertility and oral contraceptive use

Reproductive-related factors play a major role in the aetiology of cancers of the breast, ovary and endometrium. Pregnancy history influences the risk of each of these cancers, and oral contraceptive use modifies the risks of ovarian and endometrial cancers, although its effect on breast cancer risk is less certain. We analysed recent time trends in the incidence and mortality of these cancers in England and Wales and assessed whether they can be explained by changes in fertility and oral contraceptive use. During 1962-87, there were significant increases in the overall incidence of breast cancer (0.95% increase per annum) and ovarian cancer (0.76% per annum) but little increase in endometrial cancer (0.13% per annum). At young ages incidence of each of the cancers has declined in recent years, whereas at older ages there have been substantial increases. Mortality data show similar time trends. In analyses by birth cohort, incidence of each of the cancers increased steeply for successive cohorts born before the turn of the century, and more slowly for cohorts thereafter, reaching a maximum for those born in the 1920s, and decreased for those born subsequently. The increases in incidence for women born before the turn of the century paralleled marked declines in their fertility. The fall in risk for women born after the 1920s was not accompanied by significant increases in their fertility, but coincided with the introduction and increase in use of oral contraceptives. For ovarian and endometrial cancers this accords with strong evidence from person-based studies of the protective effect of oral contraceptives. For breast cancer, the reasons for the recent decline are not clear. It would accord with recent suggestions of a long-term protective effect of oral contraceptives, on which further studies are needed. It is also possible, however, that changes in other risk factors such as dietary fat intake and menarcheal age might have contributed to the recent declines in the risk of these cancers.

The epidemiology of ovarian cancer

Ovarian cancer is the second most common cancer of the female reproductive system and the leading cause of death from gynecologic malignancies. In 1995, 26,600 women will be diagnosed with ovarian cancer in the U.S., and 14,500 women will die from the disease. Between 1986-1900, the overall age-adjusted incidence was 14.3/100,000 women; mortality was 7.8/100,000 women. Ovarian cancer, rare before age 40, increases steeply thereafter and peaks at ages 65-75. Incidence and mortality rates are higher among white women than among African-American women. Over the last three decades, ovarian cancer incidence has remained stable in high-risk countries, while an increasing trend has been reported in low-risk countries. Despite recent advancements in treatment, the overall five-year survival rates continues to be low (39%). Over 70% of ovarian tumors are diagnosed when regional or distant involvement has already occurred, causing survival rates to remain stable. The etiology of ovarian cancer is poorly understood. Most studies have focused on the epidemiology of invasive epithelial ovarian tumors, while few have explored the epidemiology of epithelial tumors of low malignant potential and nonepithelial tumors. Factors associated with an increased risk for invasive epithelial ovarian cancer include age, race, nulliparity, family history of ovarian cancer, and history of endometrial or breast cancer. Factors associated with a reduced risk are history of one or more full-term pregnancies, use of oral contraceptives, history of breast feeding, tubal ligation, and hysterectomy. Other factors such as infertility drugs, hormone replacement therapy, age at menarche, age at menopause, dietary factors, lactose intolerance, talc use, coffee and alcohol consumption have been suggested, but their role is still inconclusive.

Large increase in plasmatic 11-dehydro-TxB2 levels due to oral contraceptives

Coagulation factors, 11-dehydro-TxB2 (metabolite of TxA2) and 6-keto-PGF1 alpha (metabolite of PGI2) levels in 87 women who were treated for 9 months with oral contraceptives (OC) containing low doses of oestrogens and progestogens (Triquilar, Trinovum or Cilest) were investigated. In plasma, increases in F I, II, VII, VIII-c and 11-dehydro-TxB2 levels, but no modification of 6-keto-PGF1 alpha were observed. In urine, FPA concentration rose, but no change occurred in 11-dehydro-TxB2 and 6-keto-PGF1 alpha levels. No marked difference between the 3 OC preparations were noted. These data, and particularly the large increase of 11-dehydro-TxB2 (p < 0.01) suggest that a hypercoagulable state persists in low dosage OC users.

Depot-medroxyprogesterone acetate, other injectable contraceptives, and cervical neoplasia

The relationship between depot-medroxyprogesterone acetate (DMPA), and other injectable contraceptives and cervical neoplasia was reviewed mainly on the basis of three studies: the WHO Collaborative Study of Neoplasia and Steroid Hormone Contraceptives (2,009 cases and 9,583 controls collected in several, mainly developing, countries); a study of 369 cases of carcinoma in situ, 133 of invasive cancer and 646 controls collected by the National Tumor Registry of Costa Rica; and a cooperative study of 759 cases of invasive cervical cancer and 1,430 controls from four countries in Latin America (Costa Rica, Peru, Mexico and Colombia). There was no evidence of an appreciably elevated risk since most relative risks for ever users ranged from between 0.8 and 1.4, nor of consistent duration-risk relationship which was observed only in one study. The relative risk estimates for longest duration of use ranged from between 0.9 and 2.4. The data are still compatible with the absence of a causal association and with a moderately increased risk (up to a factor 1.5), which finds some biological plausibility as it is in agreement with the overall evidence of the relation between oral contraceptives and cervical neoplasia.