Epithelial ovarian cancer risk among women with polycystic ovary syndrome

Identification of common mechanisms between endometriosis and ovarian cancer

PURPOSE

To determine common molecular markers between endometriosis and ovarian cancer.

METHODS

Patients included women who underwent laparoscopic excision of ovarian endometriotic lesions (n = 7), healthy non-pregnant women with normal pelvises, who underwent excision of normal peritoneum (n = 7). Two epithelial ovarian cancer (EOC) cell lines were also utilized. Expression of transforming growth factor (TGF)-β1, cyclooxygenase (COX)-2, vascular endothelial growth factor (VEGF), estrogen receptor (ER)-1α, progesterone receptor (PR), androgen receptor (AR), and aromatase was evaluated by real-time RT-PCR.

RESULTS

Endometriosis and EOC cells manifested significantly higher mRNA levels of TGF-β1, COX-2, VEGF, ER-1α, AR, and aromatase, while they expressed significantly lower mRNA levels of PR.

CONCLUSIONS

Increased TGF-β1, COX-2, VEGF, ER-1α, AR, and aromatase and decreased PR in endometriotic as well as EOC cells suggests a potential association between these two disease processes. This association is important, as it may reveal common mechanisms for both diseases.

Modulation of inflammatory signaling pathways by phytochemicals in ovarian cancer

Inflammation has been suggested to be involved in cancer development and progression. Many clinical and experimental studies have shown that inflammation could contribute to ovarian carcinogenesis through activation of the NF-κB and AP-1 pathways by chronic inflammatory mediators. Phytochemicals, which are natural compounds derived from fruits and vegetables, have shown anti-inflammatory and anti-cancer effects. Due to their relatively low toxicity and easy accessibility, phytochemicals have been investigated for their chemopreventive potential against various cancers. In this review, we discuss the role of phytochemicals in preventing ovarian cancer through anti-inflammatory mechanisms.

Androgens stimulate telomerase expression, activity and phosphorylation in ovarian adenocarcinoma cells

Androgens have been implicated in increasing ovarian cancer risk. Most ovarian cancer cells have high telomerase activity which is effective in inducing ovarian carcinogenesis. The purpose of this study was to investigate the effects of testosterone and androstenedione on the viability of an ovarian adenocarcinoma cell line, the activity and expression of telomerase, and the phosphorylation status of its catalytic subunit in these cells. Results showed that androgens significantly increased the viability of ovarian cancer cells and that these hormones induced the expression, activity and phosphorylation of telomerase. This upregulation was blocked by phosphatidylinositol 3-kinase pathway inhibitors. These findings might have implications for understanding the role of androgens in ovarian carcinogenesis.

Microenvironment and pathogenesis of epithelial ovarian cancer

Multiple genetic alterations play a role in the pathogenesis of ovarian cancer. Although many key proteins and pathways involved in ovarian carcinogenesis and metastasis have been discovered, knowledge of the early steps leading to malignancy remains poorly understood. This poor understanding stems from lack of data from early-stage cancers and absence of a well-established premalignant state universal to all ovarian cancer subtypes. Existing evidence suggests that ovarian cancers develop either through a stepwise mutation process (low-grade pathway), through genetic instability resulting in hastened metastasis (high-grade pathway), or more recently through what has been described as the "'fimbrial-ovarian' serous neoplasia theory." In this latter model, ovarian serous cancers evolve from premalignant lesions in the distal fallopian tube called tubal intraepithelial carcinoma. In this manuscript, we review key genetic and molecular changes that occur in cancer cell progression and suggest a model of ovarian cancer pathogenesis involving both tumor cell mutations and microenvironmental factors.

Are gonadotrophins tumorigenic--a critical review of clinical and experimental data

The growth of many gonadal and extragonadal tumors is stimulated by gonadal sex hormones. Because gonadal hormone production is regulated by pituitary gonadotrophins, the latter hormones can be considered as indirect tumor promoters. In addition, there is a growing body of evidence that both gonadal (e.g. ovarian cancer) and extragonadal (e.g. breast, uterus, prostate and adrenal) tumors express gonadotrophin receptors, indicating the possibility of a direct tumorigenic role for FSH and LH. The purpose of this brief review is to present a critical evaluation of the current information, both clinical and experimental, about the direct involvement of gonadotrophins in the induction and growth of gonadal and extragonadal tumors.

Oncological repercussions of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a highly prevalent endocrine disorder that has been associated with insulin resistance and metabolic syndrome. Evidence has suggested that PCOS may be associated with the appearance of certain types of cancer, particularly endometrial, ovarian and breast cancer. The objective of this review was to collect further evidence of these correlations and to identify their possible mechanisms.

Polycystic ovary syndrome and the risk of gynaecological cancer: a systematic review

The objective of this study was to perform a systematic review of the literature to determine whether there is an association between polycystic ovary syndrome (PCOS) and gynaecological malignancy. Medline and Embase databases (1968-2008) were searched to identify publications on the association between PCOS and gynaecological cancers including breast cancer. Studies were selected that examined the association between PCOS and all types of gynaecological malignancies. A total of 19 studies exploring the association between PCOS and breast, endometrial and ovarian cancer were identified. Of these, only eight could be included after review. The data showed variability in the definition of PCOS. A meta-analysis of the data suggests that women with PCOS are more likely to develop cancer of the endometrium (OR 2.70, 95% CI 1.00-7.29) and ovarian cancer (OR 2.52, 95% CI 1.08-5.89) but not breast cancer (OR 0.88, 95% CI 0.44-1.77). Women with PCOS appear to be three times more likely to develop endometrial cancer but are not at increased risk of breast cancer. There is insufficient evidence to implicate PCOS in the development of vaginal, vulval, cervical or ovarian cancers. The paucity of studies investigating the association between PCOS and gynaecological cancers is likely to affect the reliability of the conclusions.

Molecular pathogenesis of endometrial and ovarian cancer

Pregnancy, breastfeeding, and oral contraceptive pill use interrupt menstrual cycles and reduce endometrial and ovarian cancer risk. This suggests the importance of turnover within Mullerian tissues, where the accumulation of mutations in p53 and PTEN has been correlated with number of cycles. The most common type of endometrial cancer (Type I) is endometrioid and molecular abnormalities include mutations in PTEN, KRAS and β-catenin. The Type I precursor is Endometrial Intraepithelial Neoplasia which displays PTEN defects. Type II endometrial cancer (whose precursors are less clear) includes serous and clear cell tumors and the most common alteration is p53 mutation. For ovarian cancer, histopathologic types parallel endometrial cancer and include serous, mucinous, endometrioid, and clear cell; some molecular features are also shared. The most frequent type of ovarian cancer is high grade serous that often displays p53 mutation and its precursor lesions may originate from normal-appearing fallopian tube epithelium that contains a p53 "signature". Mutations in KRAS, BRAF and PTEN are described in mucinous, endometrioid and low grade serous cancers and these may originate from ovarian cortical inclusion cysts. A consideration of molecular and other pathogenetic features, like epidemiology and histopathology, may provide a better understanding of endometrial and ovarian cancer.

Cancer risk among infertile women with androgen excess or menstrual disorders (including polycystic ovary syndrome)

OBJECTIVE

To define relationships of androgen excesses to cancer risk.

DESIGN

Retrospective cohort study.

SETTING

Five large infertility practices.

PATIENT(S)

Among 12,193 women evaluated for infertility during 1965-1988 and traced for cancer incidence through 1999, 2,560 had androgen excess or menstrual disorders; among these, 412 met established criteria for polycystic ovary syndrome.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Cancer incidence. Derivation of standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) for cancer risk comparisons with the general population and rate ratios (RRs) for comparisons with other infertility patients.

RESULT(S)

Androgen excess/menstrual disorder patients showed significant SIRs for breast (1.31; 95% CI, 1.05-1.62) and uterine (2.02; 95% CI, 1.13-3.34) cancers and melanoma (1.96; 95% CI, 1.12-3.18). Significant associations for breast and uterine cancers were restricted to primary infertility patients (respective SIRs of 1.53 and 3.48). After adjustment for other cancer predictors, the only excess risk was for uterine cancer among primary infertility patients. Compared with women with secondary infertility and no androgen excess/menstrual disorder, those with primary infertility and a disorder had an RR of 1.88 (95% CI, 0.82-4.32). Cancer risks among the women with polycystic ovary syndrome or androgen excess disorders appeared to be similar to those in the more comprehensive group.

CONCLUSION(S)

Previous findings linking androgen excess disorders to elevated uterine cancer risks might largely reflect underlying risk profiles.

PRK1 distribution in normal tissues and carcinomas: overexpression and activation in ovarian serous carcinoma

Protein kinase C-related kinases are regulated by phosphatidylinositol-3-kinase and Rho family GTPases. The isoform PRK1 has been characterized in detail in prostate cancer, but not in other carcinomas. We analyzed our prior microarray data for PRK1 gene expression in 175 carcinomas and evaluated tissue microarrays for protein expression in 251 carcinomas and a comprehensive group of normal tissues. We also used immunoblotting to determine the levels and phosphoactivation status of PRK1, PRK2, and PDK1 in 12 ovarian serous carcinomas, SKOV3 cells, and 3 samples of normal ovarian surface epithelium (OSE). The highest average level of PRK1 messenger RNA was observed in ovarian serous carcinomas compared with all other carcinomas, including those of the prostate, bladder/ureter, breast, colon, stomach/esophagus, kidney, liver, pancreas, and lung (P = .05). By immunohistochemistry, PRK1 was observed in selected normal cells, including epithelium from the gynecologic tract and hematolymphoid elements. All serous ovarian and endometrial endometrioid adenocarcinomas and mesotheliomas were immunoreactive for PRK1. The findings in nonserous ovarian and most carcinomas from the prostate, breast, and pancreas were also positive but less consistently so. In comparison with OSE, the serous carcinomas typically had greater pPRK1/total PRK1 (P = .02) as well as greater pPDK/total PDK (P = .01). The relative phosphorylation status of these 2 kinases correlated within each sample. In summary, PRK1 is present in various malignancies, but especially in serous carcinomas, where the increased activation status of PRK1 and its upstream regulator, PDK, as compared with normal OSE suggests a role in ovarian cancer development or progression.

C-reactive protein and ovarian cancer: a prospective study nested in three cohorts (Sweden, USA, Italy)

OBJECTIVES

Inflammatory processes may influence the risk of epithelial ovarian cancer, but available epidemiological evidence is limited and indirect. Circulating C-reactive protein (CRP), a sensitive marker of inflammation, may serve as a direct biological marker of an underlying association.

METHODS

The association between ovarian cancer risk and pre-diagnostic circulating CRP was tested in a case-control study nested within three prospective cohorts from Sweden, USA, and Italy. The study included 237 cases and 427 individually matched controls. CRP was measured in stored blood samples by high-sensitivity immunoturbidimetric assay. Odds ratios (OR) and 95% confidence intervals (CI) were calculated by conditional logistic regression.

RESULTS

Overall, CRP was not related to risk of ovarian cancer. However, a marked increase in risk was observed for CRP concentrations >10 mg/l: OR (95% CI) 4.4 (1.8-10.9), which remained significant after limiting analyses to cases diagnosed more than two or five years after blood donation (OR 3.0 (1.2-8.0) and 3.6 (1.0-13.2), respectively). Risk of mucinous tumors increased with high CRP, but the number of cases in this analysis was small.

CONCLUSION

Study results offer additional support to the concept that chronic inflammation plays a role in epithelial ovarian cancer.

Prediagnostic circulating follicle stimulating hormone concentrations and ovarian cancer risk

Gonadotropins have been indicted in ovarian carcinogenesis but direct evidence has been limited and inconsistent. The aim of this study was to determine the association between prediagnostic levels of follicle stimulating hormone (FSH) and subsequent development of invasive epithelial ovarian cancer. A nested case-control study was conducted using cases and controls drawn from three cohorts: CLUE I and CLUE II of Washington County, MD, and the Island of Guernsey Study, United Kingdom. In total, 67 incident invasive epithelial ovarian cancer cases were each matched to 1 to 2 controls on age, menopausal status, time since last menstrual period, current hormone use and other relevant factors. FSH concentrations were classified into ranked thirds of low, medium or high based on the distribution among controls. Conditional logistic regression was used to estimate the odds ratio (OR) across increasing thirds of FSH concentrations. Results of the analysis showed that ovarian cancer risk decreased with higher FSH concentrations (p-trend = 0.005). Compared with the lowest third of FSH concentrations, the OR among those in the middle and highest thirds were 0.45 [95% Confidence Interval (CI): 0.20-1.00] and 0.26 (95% CI: 0.10-0.70), respectively. Associations persisted after excluding cases diagnosed within 5 years of follow-up. In conclusion, a reduction in subsequent risk of invasive epithelial ovarian cancer was observed among women with higher circulating FSH concentrations. These findings contradict the hypothesized role of FSH as a risk factor in ovarian carcinogenesis.

Androgen-related expression of G-proteins in ovarian cancer

BACKGROUND

Epidemiological and in vitro data implicate androgens in the aetiology of ovarian cancer, but the mechanisms by which this is mediated are unclear. In this study, we wished to examine the effects of androgens on gene expression in ovarian cancer.

METHODS

The expression of androgen receptor (AR) in OVCAR3 and OSEC2 cells was confirmed using immunoblotting and response to androgens was measured using flow cytometric assessment of S-phase fraction. The differential gene expression between androgen stimulated and unstimulated OVCAR3 ovarian cancer cells was examined with a cDNA microarray. The upregulation of a subset of these genes was then confirmed with reverse transcriptase PCR in both OVCAR3 and OSEC2, an ovarian epithelial cell line. Finally, the clinical significance of this upregulation was investigated by examining the expression of Rab25 and Rab35, two G-protein-related molecules in an ovarian cancer tissue microarray (TMA).

RESULTS

OVCAR3 and OSEC2 cells were shown to express the AR and showed an increase in S-phase fraction in response to androgen treatment. Treatment of OVCAR3 cells with androgen resulted in a significant upregulation of 121 genes. These findings were confirmed for a subset of seven monomeric G-protein-related genes in both OVCAR3 and OSEC2 cells. After staining for Rab25 and Rab35, the majority of TMA sections examined showed expression for Rab25 (92%) and Rab35 (95%). The expression of Rab25 correlated with histological grade, and expression was higher in endometrioid (median histoscore 10.5) than serous (7.5) or mucinous (5.3) tumours. The expression of Rab25 correlated positively with AR expression supporting its role as an androgen responsive gene in ovarian cancer.

CONCLUSIONS

These results suggest that androgens can effect expression of the oncogenic GTPases in ovarian cancer. We propose that the androgen responsive Rab35 may have clinical importance as a biomarker of AR function.

Current understanding of risk factors for ovarian cancer

OPINION STATEMENT

Ovarian cancer is the deadliest gynecologic cancer. Unlike many cancers such as breast, cervical and colon cancers, there is no easily clinically identifiable pre-malignant phase of this malignancy making early identification difficult. Similarly, unlike lung, head and neck, and skin cancers, there is not easily identifiable risk factor making prevention short of oophorectomy difficult. Even so, theories as to the causative factors of ovarian cancer continue to evolve making our understanding of the genesis of ovarian cancer more clear. Genetics, parity, environment, hormonal factors, and inflammation all play an important and pivotal role in the development of ovarian cancer. The most current understanding of these elements and their respective contribution to the development of this cancer are presented in this chapter.

Role of genetic polymorphisms and ovarian cancer susceptibility

The value of identifying women with an inherited predisposition to epithelial ovarian cancer has become readily apparent with the identification of the BRCA1, and BRCA2 genes. Women who inherit a deleterious mutation in either of these genes have a very high lifetime risk of ovarian cancer (10-60%) and to some extent, increased risks of fallopian tube and peritoneal cancer. These highly lethal cancers are almost completely prevented by prophylactic salpingoophorectomy. BRCA1/2 mutation testing has become the accepted standard of care in families with a strong history of breast and/or ovarian cancer. This approach has the potential to reduce ovarian cancer mortality by about 10%. Although the ability to perform genetic testing for BRCA1 and 2 represents a significant clinical advance, the frequency of mutations in these high penetrance ovarian cancer susceptibility genes is low in most populations. There is evidence to suggest that ovarian cancer susceptibility might be affected by common low penetrance genetic polymorphisms like it was shown for several common disorders like diabetes or breast cancer. Although such polymorphisms would increase risk to a lesser degree, they could contribute to the development of a greater proportion of ovarian cancers by virtue of their higher frequencies in the population. It has been shown that the most powerful approach to studying low penetrance genes is an association study rather than a linkage study design. This review describes the efforts that have been made in this field by individual case-control studies and through multi-center collaborations as part of international consortia such as the Ovarian Cancer Association Consortium (OCAC).

Use of fertility drugs and risk of ovarian cancer: Danish Population Based Cohort Study

OBJECTIVE

To examine the effects of fertility drugs on overall risk of ovarian cancer using data from a large cohort of infertile women.

DESIGN

Population based cohort study.

SETTING

Danish hospitals and private fertility clinics.

PARTICIPANTS

54,362 women with infertility problems referred to all Danish fertility clinics during 1963-98. The median age at first evaluation of infertility was 30 years (range 16-55 years), and the median age at the end of follow-up was 47 (range 18-81) years. Included in the analysis were 156 women with invasive epithelial ovarian cancer (cases) and 1241 subcohort members identified in the cohort during follow-up in 2006.

MAIN OUTCOME MEASURE

Effect of four groups of fertility drugs (gonadotrophins, clomifene citrate, human chorionic gonadotrophin, and gonadotrophin releasing hormone) on overall risk of ovarian cancer after adjustment for potential confounding factors.

RESULTS

Analyses within cohort showed no overall increased risk of ovarian cancer after any use of gonadotrophins (rate ratio 0.83, 95% confidence interval 0.50 to 1.37), clomifene (1.14, 0.79 to 1.64), human chorionic gonadotrophin (0.89, 0.62 to 1.29), or gonadotrophin releasing hormone (0.80, 0.42 to 1.51). Furthermore, no associations were found between all four groups of fertility drugs and number of cycles of use, length of follow-up, or parity.

CONCLUSION

No convincing association was found between use of fertility drugs and risk of ovarian cancer.

The haplotype of two FSHR polymorphisms in ovarian cancer--a potential role of ethnology in risk modification

OBJECTIVES

The precise role of gonadotropins in the carcinogenesis of epithelial ovarian cancer remains uncertain. Recently, the haplotype of two single nucleotide polymorphisms, Thr307Ala (rs6165) and Asn680Ser (rs6166), has been described as a risk factor for ovarian cancer in Chinese women. In this study we investigated the impact of this haplotype regarding the risk to develop ovarian cancer as well as possible effects upon the clinical course in a Caucasian patient sample.

SUBJECTS AND METHODS

Determination of genotypes in 115 patients with primary epithelial ovarian cancer and 115 age-matched controls was performed by Pyrosequencing for Thr307Ala and by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique for Asn680Ser.

RESULTS

Analysis of the genotypes revealed almost complete linkage disequilibrium of both SNPs. The distribution of genotypes was not statistically significant different between ovarian cancer patients and age-matched controls. Clinical parameters such as overall survival, CA12-5 elevation at primary diagnosis, age at diagnosis, FIGO stage, grading, and platinum resistance were not statistically significantly different regarding genotypes.

CONCLUSIONS

We could not confirm the FSHR Ala307-Ser680 haplotype as a risk factor for epithelial ovarian cancer in Caucasian women. Hence, the modification of tumor risk may be affected by the ethnology of the patient collective. We could not find any associations of clinical parameters or course of the disease with the different genotypes.

Epidemiology of ovarian cancer

Ovarian cancer represents the sixth most commonly diagnosed cancer among women in the world, and causes more deaths per year than any other cancer of the female reproductive system. Despite the high incidence and mortality rates, the etiology of this disease is poorly understood. Established risk factors for ovarian cancer include age and having a family history of the disease, while protective factors include increasing parity, oral contraceptive use, and oophorectomy. Lactation, incomplete pregnancies, and surgeries such as hysterectomy and tubal ligation may confer a weak protective effect against ovarian cancer. Infertility may contribute to ovarian cancer risk among nulliparous women. Other possible risk factors for ovarian cancer include postmenopausal hormone-replacement therapy and lifestyle factors such as cigarette smoking and alcohol consumption. Many of the causes of ovarian cancer are yet to be identified. Additional research is needed to better understand the etiology of this deadly disease.

Infertility as a cancer risk factor - a review

Ovarian, endometrial and breast cancers are associated with several risk factors, such as low parity, infertility, early age at menarche, and late age at menopause. Frequently most of these risk factors coexist in infertile patients and some studies suggested that the different infertility causes can be involved in cancer risk development. In particular case-control and cohort studies investigated the possible role of ovulatory disorders, endometriosis and unexplained infertility in increasing the risk of this disease. Most studies have shown no overall increased risk in invasive ovarian cancer in subfertile patients, although nulliparity has been consistently associated with increased rates of ovarian tumor, in particular with borderline and endometrioid cancers in patients with a history of endometriosis. Different studies reported that infertile women are not at risk for breast cancer. However, women affected by infertility may be more at risk for endometrial cancer, particularly if affected by ovulatory disorders. Moreover, infertility is now often treated with medical devices that could by themselves modify the hormonal environment and be cofactors in the cellular changes towards cancer development. However, although early studies suggested that infertility medications were associated to increased risk in ovarian cancer, subsequent studies have been mainly reassuring, although suggesting that type and duration of medical treatment can increase the malignancy risk. An increased risk of endometrial cancer in patients undergoing infertility treatment has been reported, as expected by the similar structure shared by clomiphene and tamoxiphene. Since breast cancer is widely recognized as having a hormonal etiology, a possible role of fertility medications to promote cancer has been hypothesized. However, many large studies were not able to find an associated risk of breast cancer. In conclusion, nowadays, firm answers about the precise effects of infertility and its treatment on cancer risk are not available but findings are generally reassuring. Further studies about fertility drug treatments on larger populations may offer in the future longer follow-up and more precise data with better adjustments for confounding factors.

Body size in early life and risk of epithelial ovarian cancer: results from the Nurses' Health Studies

Adult body mass index (BMI) has been associated with ovarian cancer risk, but few studies have examined body size earlier in life. We prospectively examined associations of body fatness at ages 5 and 10, BMI at age 18, height, and birthweight with risk of epithelial ovarian cancer in the Nurses' Health Study (NHS: 110 311 women, 735 cases) and Nurses' Health Study II (NHSII: 113 059 women, 137 cases). Cox proportional hazards regression was used to estimate relative risks (RRs) and 95% confidence intervals (CIs). There was a weak inverse association between average body fatness at ages 5 and 10 and risk in the NHS (RR for heaviest vs most lean=0.81, 95% CI: 0.53-1.24, P for trend=0.04) and a nonsignificant positive association in the NHSII (RR=2.09, 95% CI: 0.98-4.48, P for trend=0.10), possibly due to differences in age and menopausal status. Height was positively associated with risk in both cohorts (RR for >or=1.75 vs <1.6 m=1.43, 95% CI: 1.05-1.96, P for trend=0.001). Body mass index at the age of 18 years and birthweight were not associated with risk. Further research should examine the biological mechanisms underlying the observed associations.

Birth spacing and maternal risk of invasive epithelial ovarian cancer in a Swedish nationwide cohort

OBJECTIVE

Pregnancies reduce the risk of ovarian cancer, and among multiparous women, levels of circulating progesterone might be higher during pregnancies with wider birth spacing. We hypothesized that childbirth with wider birth spacing might reduce maternal risk of invasive epithelial ovarian cancer more than births with narrower spacing.

METHODS

We conducted a case-control study nested in a nationwide cohort of Swedish women from 1961 to 2001. We selected five individually age-matched controls for each case of invasive epithelial ovarian cancer, and analysis for the effect of birth spacing was performed for 5,341 cases and 29,047 controls. We applied unconditional logistic regression analyses adjusting for age, ages at childbirth, educational level, area of residence, and gender of offspring.

RESULTS

Relative risk of invasive epithelial ovarian cancer associated with each one-year increase in average birth spacing is 1.00 (95% CI = 0.98-1.01) among all women and 0.99 (0.98-1.01) among those born before 1935 and less likely to have used oral contraceptives. Further analyses on the biparous and triparous women did not find a consistent association between birth spacing and the risk of ovarian cancer.

CONCLUSIONS

Birth spacing is unlikely to be a major determinant underlying the protective effects of childbirth on ovarian cancer risk.

Fertility drugs and risk of ovarian cancer: dispelling the myth

PURPOSE OF REVIEW

Worldwide 50-80 million people suffer from infertility. Assisted reproductive technology has provided a way of overcoming infertility and childlessness. The current article will focus on data linking infertility and its treatment to ovarian cancer.

RECENT FINDINGS

Ovarian cancer risks associated with fertility drug treatment are encouraging, but not decisive. In view of the limited ability to evaluate drug effects on borderline tumors, given their rare occurrence, studies involving patient reports of prior drug exposures have noted an elevated risk of borderline tumors associated with fertility drugs. Nevertheless, the risk of invasive ovarian cancer appears to be restricted to those women who remain childless despite the infertility treatment.

SUMMARY

As long as doubt persists, it might be advisable to reflect on a few clinical recommendations: identify high-risk infertile patients for ovarian cancer, investigate preexisting cancer before fertility treatment, inform patients regarding potential risks, obtain an informed consent, avoid exposure to long periods of ovulation induction cycles that are given before patients are referred for in-vitro fertilization and embryo transfer for women at greater risk and monitor women who have been treated with these drugs, especially those who failed to conceive, regularly and thoroughly.

New insights into the pathogenesis of serous ovarian cancer and its clinical impact

There are only a handful of concepts concerning cancer and carcinogenesis that are currently beyond dispute. One such dogma is the adenoma-carcinoma sequence and that a multistep accumulation of genetic alterations is required for transformation from a benign to a neoplastic tissue. The inevitable derivative of this dogma is that every invasive carcinoma is in fact a missed intraepithelial tumor, and furthermore, a late evolutionary stage in the sequence of development from a precursor lesion. Until fairly recently, high-grade serous ovarian carcinoma seemed to be one of the only known deviants of these concepts. In this article, we discuss the emergence of the fallopian tube fimbria as a field of origin for high-grade serous carcinomas and present a binary model of ovarian cancer pathogenesis that takes into consideration prior epidemiologic, morphologic, and genetic data. With the rise of the fallopian tube secretory epithelial cell as a cell of origin for high-grade pelvic serous carcinomas, the need to develop tools and model systems to characterize the biology and physiology of this cell is recognized.

Genetic polymorphisms in the Paraoxonase 1 gene and risk of ovarian epithelial carcinoma

Oxidative stress during successive ovulations increases the opportunity for DNA damage to ovarian epithelial cells and the potential for malignant transformation. Paraoxonase 1 (PON1) is an endogenous free radical scavenger that reduces oxidative stress. The association of two common functional single nucleotide polymorphisms (SNP), rs854560 T>A and rs662 A>G, with the risk of epithelial ovarian cancer was examined in a population-based case-control study in Hawaii. A personal interview and blood specimens were collected from 274 women with histologically confirmed, primary ovarian cancer and 452 controls frequency matched on age and ethnicity. Odds ratios (OR) and 95% confidence intervals (95% CI) were estimated by unconditional logistic regression. Both PON1 SNPs were significantly associated with ovarian cancer risk. The ORs were 0.53 (95% CI, 0.35-0.79; P for allele-dose effect = 0.01) for women carrying the rs854560 T allele compared with women with the AA genotype and 0.65 (95% CI, 0.44-0.95; P for allele-dose effect = 0.03) for women carrying the rs662 A allele compared with women with the GG genotype. The association of the rs854560 T genotype with risk was stronger among smokers (OR, 0.33; 95% CI, 0.17-0.64; P for allele-dose effect = 0.0007) than among nonsmokers (OR, 0.68; 95% CI, 0.40-1.18; P for allele-dose effect = 0.53). The decreased risk associated with the rs854560 T allele was also stronger among obese women (OR, 0.19; 95% CI, 0.06-0.55; P for allele-dose effect = 0.007) than among nonobese women (OR, 0.62; 95% CI, 0.40-0.98; P for allele-dose effect = 0.16). Our study provides evidence for an association of two PON1 SNPs with the risk of epithelial ovarian cancer. Possible effect modification of these associations by tobacco smoking and obesity needs confirmation in other studies.

Consortium analysis of 7 candidate SNPs for ovarian cancer

The Ovarian Cancer Association Consortium selected 7 candidate single nucleotide polymorphisms (SNPs), for which there is evidence from previous studies of an association with variation in ovarian cancer or breast cancer risks. The SNPs selected for analysis were F31I (rs2273535) in AURKA, N372H (rs144848) in BRCA2, rs2854344 in intron 17 of RB1, rs2811712 5' flanking CDKN2A, rs523349 in the 3' UTR of SRD5A2, D302H (rs1045485) in CASP8 and L10P (rs1982073) in TGFB1. Fourteen studies genotyped 4,624 invasive epithelial ovarian cancer cases and 8,113 controls of white non-Hispanic origin. A marginally significant association was found for RB1 when all studies were included [ordinal odds ratio (OR) 0.88 (95% confidence interval (CI) 0.79-1.00) p = 0.041 and dominant OR 0.87 (95% CI 0.76-0.98) p = 0.025]; when the studies that originally suggested an association were excluded, the result was suggestive although no longer statistically significant (ordinal OR 0.92, 95% CI 0.79-1.06). This SNP has also been shown to have an association with decreased risk in breast cancer. There was a suggestion of an association for AURKA, when one study that caused significant study heterogeneity was excluded [ordinal OR 1.10 (95% CI 1.01-1.20) p = 0.027; dominant OR 1.12 (95% CI 1.01-1.24) p = 0.03]. The other 5 SNPs in BRCA2, CDKN2A, SRD5A2, CASP8 and TGFB1 showed no association with ovarian cancer risk; given the large sample size, these results can also be considered to be informative. These null results for SNPs identified from relatively large initial studies shows the importance of replicating associations by a consortium approach.

Proliferation of the superficial epithelium of ovaries in senile female rats following oral administration of conjugated equine estrogens

OBJECTIVE

To evaluate the effect of different concentrations of estrogen on the ovarian superficial epithelium in senile female rats.

DESIGN

Fifty female rats at 15 months of age and with irregular estrous cycles were selected and randomly divided into five experimental groups containing equal numbers of animals in each: GPROP, control group receiving vehicle only; GE0.05mg, group receiving conjugated equine estrogens (CEE) at a dose of 50 microg/kg; GE0.5mg, group receiving CEE at 500 microg/kg; GE1mg, group receiving CEE at 1 mg/kg; and GE2mg, receiving CEE at 2 mg/kg. The length of treatment was 21 days. After this period, the animals were anesthetized and the ovaries were fixed in 10% formaldehyde and processed for routine histology. Histomorphology was analyzed by light microscopy, and histomorphometrics were evaluated using the Imagelab program.

RESULTS

In the GPROP and GE0.05mg groups, the superficial epithelium of the ovary had a simple cuboidal shape, and as the estrogen dose increased, the epithelium thickened, with pseudo-stratified or stratified epithelium appearing in the GE2mg group. The animals in the group given the highest estrogen dose (GE2mg) showed the thickest ovarian epithelium and the largest perimeter and surface area of the surface ovarian epithelium (P < 0.01). However, the difference in epithelium thickness between the GE0.5mg and GE1mg groups was only slight.

CONCLUSION

Our data suggest that CEE at a dose of 2 mg/kg may induce marked proliferation of rat ovarian epithelium.

Height, body mass index, and ovarian cancer: a pooled analysis of 12 cohort studies

BACKGROUND

Although many studies have investigated the association between anthropometry and ovarian cancer risk, results have been inconsistent.

METHODS

The associations of height, body mass index (BMI), and ovarian cancer risk were examined in a pooled analysis of primary data from 12 prospective cohort studies from North America and Europe. The study population consisted of 531,583 women among whom 2,036 epithelial ovarian cancer cases were identified. To summarize associations, study-specific relative risks (RR) were estimated using the Cox proportional hazards model and then combined using a random-effects model.

RESULTS

Women with height > or =1.70 m had a pooled multivariate RR of 1.38 [95% confidence interval (95% CI), 1.16-1.65] compared with those with height <1.60 m. For the same comparison, multivariate RRs were 1.79 (95% CI, 1.07-3.00) for premenopausal and 1.25 (95% CI, 1.04-1.49) for postmenopausal ovarian cancer (P(interaction) = 0.14). The multivariate RR for women with a BMI > or =30 kg/m(2) was 1.03 (95% CI, 0.86-1.22) compared with women with a BMI from 18.5 to 23 kg/m(2). For the same comparison, multivariate RRs were 1.72 (95% CI, 1.02-2.89) for premenopausal and 1.07 (95% CI, 0.87-1.33) for postmenopausal women (P(interaction) = 0.07). There was no statistically significant heterogeneity between studies with respect to height or BMI. BMI in early adulthood was not associated with ovarian cancer risk.

CONCLUSION

Height was associated with an increased ovarian cancer risk, especially in premenopausal women. BMI was not associated with ovarian cancer risk in postmenopausal women but was positively associated with risk in premenopausal women.

Risk factors for ovarian cancer: an overview with emphasis on hormonal factors

Ovarian cancer is the fifth most frequently occurring cancer among women and leading cause of gynecological cancer deaths in North America. Although the etiology of ovarian cancer is not clear, certain factors are implicated in the etiology of this disease, such as ovulation, gonadotropic and steroid hormones, germ cell depletion, oncogenes and tumor suppressor genes, growth factors, cytokines, and environmental agents. Family history of breast or ovarian cancer is a prominent risk factor for ovarian cancer, with 5-10% of ovarian cancers due to heritable risk. Reproductive factors such as age at menopause and infertility contribute to greater risk of ovarian cancer, whereas pregnancy, tubal ligation, and hysterectomy reduce risk. Oral contraceptive (OC) use has clearly been shown to be protective against ovarian cancer. In contrast, large epidemiologic studies found hormone replacement therapy (HRT) to be a greater risk factor for ovarian cancer. The marked influence of hormones and reproductive factors on ovarian cancer suggests that endocrine disrupters may impact risk; however, there is a notable lack of research in this area. Lifestyle factors such as cigarette smoking, obesity, and diet may affect ovarian cancer risk. Exposure to certain environmental agents such as talc, pesticides, and herbicides may increase risk of ovarian cancer; however, these studies are limited. Further research is needed to strengthen the database of information from which an assessment of environmental and toxicological risk factors for ovarian cancer can be made.

Early Events in the Pathogenesis of Epithelial Ovarian Cancer

Ovarian carcinogenesis, as in most cancers, involves multiple genetic alterations. A great deal has been learned about proteins and pathways important in the early stages of malignant transformation and metastasis, as derived from studies of individual tumors, microarray data, animal models, and inherited disorders that confer susceptibility. However, a full understanding of the earliest recognizable events in epithelial ovarian carcinogenesis is limited by the lack of a well-defined premalignant state common to all ovarian subtypes and by the paucity of data from early-stage cancers. Evidence suggests that ovarian cancers can progress both through a stepwise mutation process (low-grade pathway) and through greater genetic instability that leads to rapid metastasis without an identifiable precursor lesion (high-grade pathway). In this review, we discuss many of the genetic and molecular disorders in each key process that is altered in cancer cells, and we present a model of ovarian pathogenesis that incorporates the role of tumor cell mutations and factors in the host microenvironment important to tumor initiation and progression.

Polycystic ovary syndrome: a follow-up study on diabetes mellitus, cardiovascular disease and malignancy 15-25 years after ovarian wedge resection

The aim of the present study was to examine the occurrence of possibly associated diseases in 149 women with polycystic ovary syndrome (PCOS) 15-25 years after ovarian wedge resection. Diabetes mellitus was the only associated disease which showed a significantly increased occurrence. No significant change in cancers specific for the female gender was seen. Likewise, the relative risk of cardiovascular disease was not affected. However, the power of the statistical test was low. This long-term study indicates increased risk of diabetes mellitus in PCOS patients. The study group is too small to give any conclusions about other possibly associated diseases. Family histories, however, revealed that associated diseases are related to genetic disposition rather than to PCOS per se.

Association between single-nucleotide polymorphisms in hormone metabolism and DNA repair genes and epithelial ovarian cancer: results from two Australian studies and an additional validation set

Although some high-risk ovarian cancer genes have been identified, it is likely that common low penetrance alleles exist that confer some increase in ovarian cancer risk. We have genotyped nine putative functional single-nucleotide polymorphisms (SNP) in genes involved in steroid hormone synthesis (SRD5A2, CYP19A1, HSB17B1, and HSD17B4) and DNA repair (XRCC2, XRCC3, BRCA2, and RAD52) using two Australian ovarian cancer case-control studies, comprising a total of 1,466 cases and 1,821 controls of Caucasian origin. Genotype frequencies in cases and controls were compared using logistic regression. The only SNP we found to be associated with ovarian cancer risk in both of these two studies was SRD5A2 V89L (rs523349), which showed a significant trend of increasing risk per rare allele (P = 0.00002). We then genotyped another SNP in this gene (rs632148; r(2) = 0.945 with V89L) in an attempt to validate this finding in an independent set of 1,479 cases and 2,452 controls from United Kingdom, United States, and Denmark. There was no association between rs632148 and ovarian cancer risk in the validation samples, and overall, there was no significant heterogeneity between the results of the five studies. Further analyses of SNPs in this gene are therefore warranted to determine whether SRD5A2 plays a role in ovarian cancer predisposition.

Gestational age and fetal growth in relation to maternal ovarian cancer risk in a Swedish cohort

BACKGROUND

Pregnancy influences subsequent maternal ovarian cancer risk. To date, there is limited evidence whether two characteristics of pregnancy, gestational age and birth weight, could modify risk.

MATERIALS AND METHODS

We studied 1.1 million Swedish women who delivered singleton births between 1973 and 2001. Information on infant gestational age and birth weight was abstracted from the nationwide Swedish Birth Register. Women were followed prospectively through linkage with other population-based registers for occurrence of ovarian cancer, death, or emigration through 2001. Hazard ratios [relative risk (RR), 95% confidence interval (95% CI)] from Cox models were used to estimate associations between gestational age, birth weight, and epithelial ovarian cancer risk.

RESULTS

During 12.6 million person-years, 1,017 epithelial ovarian cancers occurred. Mean age at diagnosis was 43 years. Compared with women with term deliveries (>/=40 weeks), women with moderately (35-36 weeks) or very (<35 weeks) preterm deliveries had increased risks of epithelial ovarian cancer (RR 1.4, 95% CI 1.0-2.0 and RR 2.3, 95% CI 1.3-3.8, respectively). In contrast, women giving birth to small-for-gestational-age babies had a reduced risk (RR 0.7, 95% CI 0.4-1.0). Stratifying on birth weight and gestational age, there was a strong protective effect of low birth weight on maternal risk of epithelial ovarian cancer among term deliveries, whereas birth weight seemed to have little effect among preterm births (P(interaction) = 0.022).

CONCLUSIONS

Our results lend further support that the hormonal milieu of a pregnancy may modify long-term risk of developing ovarian cancer. 32).

Gonadotropins and ovarian cancer

Ovarian epithelial cancer (OEC) accounts for 90% of all ovarian cancers and is the leading cause of death from gynecological cancers in North America and Europe. Despite its clinical significance, the factors that regulate the development and progression of ovarian cancer are among the least understood of all major human malignancies. The two gonadotropins, FSH and LH, are key regulators of ovarian cell functions, and the potential role of gonadotropins in the pathogenesis of ovarian cancer is suggested. Ovarian carcinomas have been found to express specific receptors for gonadotropins. The presence of gonadotropins in ovarian tumor fluid suggests the importance of these factors in the transformation and progression of ovarian cancers as well as being prognostic indicators. Functionally, there is evidence showing a direct action of gonadotropins on ovarian tumor cell growth. This review summarizes the key findings and recent advances in our understanding of these peptide hormones in ovarian cancer development and progression and their role in potential future cancer therapy. We will first discuss the supporting evidence and controversies in the "gonadotropin theory" and the use of animal models for exploring the involvement of gonadotropins in the etiology of ovarian cancer. The role of gonadotropins in regulating the proliferation, survival, and metastasis of OEC is next summarized. Relevant data from ovarian surface epithelium, which is widely believed to be the precursor of OEC, are also described. Finally, we will discuss the clinical applications of gonadotropins in ovarian cancer and the recent progress in drug development.

Trinucleotide repeat polymorphisms in the androgen receptor gene and risk of ovarian cancer

INTRODUCTION

Androgens may play a role in the development of ovarian cancers. Two trinucleotide repeat polymorphisms have been described in exon 1 of the androgen receptor (AR) gene that may affect its function. Previous studies of ovarian cancer and AR repeat polymorphisms have been inconsistent.

METHODS

We analyzed CAG and GGC repeat length polymorphisms in the AR gene using data from a population-based case-control study of ovarian cancer that included 594 cases and 681 controls. Repeat lengths were determined by fluorescent DNA fragment analysis using ABI GeneScan software. Change point models were used to determine appropriate repeat length cutoff points by race (African American versus Caucasian) for both the shorter and longer CAG and GGC repeats.

RESULTS

No relationship was observed between CAG repeat length and ovarian cancer among Caucasians. Among African Americans, having a short repeat length on either allele was associated with a 2-fold increase in ovarian cancer risk (age-adjusted odds ratio, 2.2; 95% confidence interval, 1.1-4.1). Having short CAG repeat lengths for both alleles was associated with a 5-fold increased risk for developing ovarian cancer (age-adjusted odds ratio, 5.4; 95% confidence interval, 1.4-1.7). No relationship with the GGC repeat length polymorphisms was observed.

CONCLUSION

These results suggest that having a short CAG repeat length in AR increases ovarian cancer risk in African Americans. The failure to observe this relationship in Caucasians may be due to the rarity of such short CAG alleles in this population or could reflect racial differences in disease etiology.

C-reactive protein concentrations and subsequent ovarian cancer risk

OBJECTIVE

To estimate the association between prediagnostic levels of C-reactive protein (CRP), a marker of chronic systemic inflammation, and subsequent development of ovarian cancer.

METHODS

A multicenter, nested, case-control study was conducted, including women who developed ovarian cancer (case patients) and women who were cancer-free (controls) from the following cohorts: CLUE ("Give us a CLUE to cancer and heart disease") cohorts of Washington County, Maryland, the Columbia, Missouri Serum Bank, and the Island of Guernsey Prospective Study, United Kingdom. A total of 167 incident invasive epithelial ovarian cancer cases were identified and each matched to an average of two controls on cohort, age, race, menopausal status, time since last menstrual period, current hormone use, date of recruitment, and time of day of blood draw. Baseline serum samples were assayed for CRP concentrations, and estimates of risk associated with CRP levels were assessed using conditional logistic regression.

RESULTS

Ovarian cancer risk was positively associated with increasing CRP concentrations. The risk of developing ovarian cancer among women in the highest third of the distribution of CRP compared with those in the lowest third was 1.72 (95% confidence interval 1.06-2.77), with evidence of an increasing risk with increasing concentration of CRP (P trend=0.02). Similar associations were observed using established clinical CRP cutpoints for heart disease risk (odds ratio 2.03, 95% confidence interval 1.20-3.47 for 3-10 mg/L compared with less than 1 mg/L, P trend=.008). If this association is causal, roughly 23% of ovarian cancer cases are attributed to chronic inflammation as indicated by elevated CRP concentrations.

CONCLUSION

Higher circulating CRP concentrations in women who subsequently developed ovarian cancer support the hypothesized role of chronic inflammation in ovarian carcinogenesis.

LEVEL OF EVIDENCE

II.

LH/hCG action and development of ovarian cancer--a short review on biological and clinical/epidemiological aspects

A link between infertility therapy, especially ovulation induction therapy using gonadotropins, and the development of ovarian cancer has long been an issue of debate since an epidemiological report supporting the possibility appeared in 1992. A number of clinical/epidemiological and biological studies, including a few that we conducted, have revealed various facts regarding this issue. The aim of this short review was to summarize the last 10 years findings and to address the implications of the debates on this issue.

Hormonal therapy in ovarian cancer

Ovarian carcinoma continues to be the leading cause of death due to gynecological malignancy. Epidemiologic studies indicate that steroid hormones play roles in ovarian carcinogenesis. Gonadotropins, estrogen, and androgen may be causative factors, while gonadotropin-releasing hormone and progesterone may be protective factors in ovarian cancer pathogenesis. Experimental studies have shown that hormonal receptors are expressed in ovarian cancer cells and mediate the growth-stimulatory or growth-inhibitory effects of the hormones on these cells. Hormonal therapeutic agents have been evaluated in several clinical trials. Most of these trials were conducted in patients with recurrent or refractory ovarian cancer, with modest efficacy and few side effects. Better understanding of the mechanisms through which hormones affect cell growth may improve the efficacy of hormonal therapy. Molecular markers that can reliably predict major clinical outcomes should be investigated further in well-designed trials.

Obesity and the risk of epithelial ovarian cancer: a systematic review and meta-analysis

Obesity is a risk factor for several hormone-related cancers but evidence for an effect on risk of epithelial ovarian cancer remains inconclusive. Many studies evaluating this association have had insufficient statistical power to detect modest effects, particularly for histological subtypes of ovarian cancer. We have therefore assembled the published evidence on obesity and ovarian cancer in a systematic literature review and meta-analysis. We identified eligible studies using Medline and manual review of retrieved references, and included all population-based studies that assessed the association between overweight, body mass index (BMI25-29.9) and obesity (BMI30) and histologically confirmed ovarian cancer. Meta-analysis was restricted to those studies that expressed effect as an odds ratio (OR), risk ratio, or standardised incidence ratio and 95% confidence interval (CI). We identified 28 eligible studies, of which 16 on adult obesity and 9 on obesity in early adulthood were suitable for meta-analysis. Overall, 24 of 28 studies reported a positive association between obesity and ovarian cancer, and in 10 this reached statistical significance. The pooled effect estimate for adult obesity was 1.3 (95%CI1.1-1.5) with a smaller increased risk for overweight (OR1.2;95%CI1.0-1.3). The pooled OR was stronger among case-control studies (OR=1.5) than cohort studies (OR=1.1). Overweight/obesity in early adulthood was also associated with an increased risk of ovarian cancer. There was no evidence that the association varied for the different histological subtypes of ovarian cancer. Ovarian cancer should be added to the list of cancers likely to be related to obesity.

Endocrine signaling in ovarian surface epithelium and cancer

Ovarian cancer is the sixth most common cancer and the fifth leading cause of cancer-related death among women in developed countries. Greater than 85% of human ovarian cancer arises within the ovarian surface epithelium (OSE), with the remainder derived from granulosa cells or, rarely, stroma or germ cells. The pathophysiology of ovarian cancer is the least understood among all major human malignancies because of a poor understanding of the aetiological factors and mechanisms of ovarian cancer progression. There is increasing evidence suggesting that several key reproductive hormones, such as GnRH, gonadotrophins and sex steroids, regulate the growth of normal OSE and ovarian cancer cells. The objective of this review was to highlight the effects of these endocrine factors on ovarian cancer cell growth and to summarize the signalling mechanisms involved in normal human OSE and its neoplastic counterparts.

Differentially androgen-modulated genes in ovarian epithelial cells from BRCA mutation carriers and control patients predict ovarian cancer survival and disease progression

Epidemiological studies have implicated androgens in the etiology and progression of epithelial ovarian cancer. We previously reported that some androgen responses were dysregulated in malignant ovarian epithelial cells relative to control, non-malignant ovarian surface epithelial (OSE) cells. Moreover, dysregulated androgen responses were observed in OSE cells derived from patients with germline BRCA-1 or -2 mutations (OSEb), which account for the majority of familial ovarian cancer predisposition, and such altered responses may be involved in ovarian carcinogenesis or progression. In the present study, gene expression profiling using cDNA microarrays identified 17 genes differentially expressed in response to continuous androgen exposure in OSEb cells and ovarian cancer cells as compared to OSE cells derived from control patients. A subset of these differentially affected genes was selected and verified by quantitative real-time reverse transcription-polymerase chain reaction. Six of the gene products mapped to the OPHID protein-protein interaction database, and five were networked within two interacting partners. Basic leucine zipper transcription factor 2 (BACH2) and acetylcholinesterase (ACHE), which were upregulated by androgen in OSEb cells relative to OSE cells, were further investigated using an ovarian cancer tissue microarray from a separate set of 149 clinical samples. Both cytoplasmic ACHE and BACH2 immunostaining were significantly increased in ovarian cancer relative to benign cases. High levels of cytoplasmic ACHE staining correlated with decreased survival, whereas nuclear BACH2 staining correlated with decreased time to disease recurrence. The finding that products of genes differentially responsive to androgen in OSEb cells may predict survival and disease progression supports a role for altered androgen effects in ovarian cancer. In addition to BACH2 and ACHE, this study highlights a set of potentially functionally related genes for further investigation in ovarian cancer.

Gonadotropins and ovarian carcinogenesis: a new era of basic research and its clinical implications

The possible relationship between gonadotropins and ovarian carcinoma development has received much attention, and in recent years, great progress has been made in basic and epidemiologic research about this issue. Gonadotropins sensitivity in the ovarian surface epithelium (OSE) and in a subset of ovarian carcinomas has been established in vivo and in vitro. Gonadotropins have been shown to induce various biologic actions in the OSE and ovarian carcinoma cells, such as changes in cell proliferation, apoptosis, cell adhesion, and chemosensitivity. These basic studies strongly suggest that gonadotropins are involved in the development and progression of ovarian carcinoma. In contrast, although earlier studies showed a significant risk of infertility therapy for ovarian carcinoma development, subsequent studies reported only slightly increased or no significant increased risk of gonadotropin stimulation and/or assisted reproductive technologies for ovarian carcinoma development. Therefore, the association between ovarian stimulation and ovarian carcinoma remains controversial. Nevertheless, since development of ovarian carcinoma in infertile women during infertility treatment is a serious concern for gynecologists, this review also covers important points for clinical practice, especially the issue of early detection of ovarian carcinoma.

Relation of Anthropometric Measurements to Ovarian Cancer Risk in a Population-based Case–control Study (United States)

OBJECTIVE

To examine the relationship between anthropometric measures and ovarian cancer by menopausal status.

METHODS

We analyzed data from a population-based case-control study comprised of 700 incident cases of epithelial ovarian cancer and 5,943 population controls from Massachusetts and Wisconsin enrolled between 1993 and 2001. In a telephone interview, information was gathered on established ovarian cancer risk factors, as well as adult height and age-specific body weight. Logistic regression was used to estimate multivariate-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for body mass index (BMI) throughout life.

RESULTS

Recent BMI had no significant association with ovarian cancer risk (P-trend 0.14 for continuous BMI), after adjustment for age and other ovarian cancer risk factors. However, a non-significant positive association (overall P-trend 0.08) was observed for BMI at age 20; the risk estimate comparing a body mass of >25 kg/m2 to the lowest quintile (<or=18.88 kg/m2) was moderately but non-significantly elevated (OR 1.46; 95% CI 0.92, 2.31).

CONCLUSION

Results of this study suggest that maintenance of a lean body mass, particularly in early adult life, may decrease ovarian cancer risk.