Body mass index and risk of ovarian cancer

Urinary interleukin-1β levels among gynecological patients

BACKGROUND

Early detection of epithelial ovarian cancer (OC) is necessary to overcome the high mortality rate of late stage diagnosis; and, examining the molecular changes that occur at early disease onset may provide new strategies for OC detection. Since the deregulation of inflammatory mediators can contribute to OC development, the purpose of this pilot study was to determine whether elevated urinary levels of Interleukin-1beta (IL-1 beta) are associated with OC and associated clinical parameters.

METHODS

Urinary and serum levels of IL-1 beta were analyzed by ELISA from a patient cohort consisting of healthy women (N = 10), women with ovarian benign disease (N = 23), women with OC (N = 32), women with other benign gynecological conditions (N = 22), and women with other gynecological cancers (N = 6).

RESULTS

Average urinary IL-1 beta levels tended to be elevated in ovarian benign (1.26 pg/ml) and OC (1.57 pg/ml) patient samples compared to healthy individuals (0.36 pg/ml). Among patients with benign disease, urinary IL-1β levels were statistically higher in patients with benign inflammatory gynecologic disease compared to patients with non-inflammatory benign disease. Interestingly, urinary IL-1 beta levels tended to be 3-6x greater in patients with benign ovarian disease or OC as well as with a concomitant family history of ovarian and/or breast cancer compared to similar patients without a family history of ovarian and/or breast cancer. Lastly, there was a pattern of increased urinary IL-1 beta with increasing body mass index (BMI); patients with a normal BMI averaged urinary IL-1 beta levels of 0.92 pg/ml, overweight BMI averaged urinary IL-1 beta levels of 1.72 pg/ml, and obese BMI averaged urinary IL-1 beta levels of 5.26 pg/ml.

CONCLUSIONS

This pilot study revealed that urinary levels of IL-1 beta are elevated in patients with epithelial OC supporting the thought that inflammation might be associated with cancer progression. Consequently, further studies of urinary IL-1 beta and the identification of an inflammatory profile specific to OC development may be beneficial to reduce the mortality associated with this disease.

Recent Advancements in Prognostic Factors of Epithelial Ovarian Carcinoma

Ovarian cancer remains the most common cause of gynecologic cancer-related death among women in developed countries. Nevertheless, subgroups of ovarian cancer patients experience relatively longer survival. Efforts to identify prognostic factors that characterize such patients are ongoing, with investigational areas including tumor characteristics, surgical management, inheritance patterns, immunologic factors, and genomic patterns. This review discusses various demographic, clinical, and molecular factors implicating longevity and ovarian cancer survival. Continued efforts at identifying these prognosticators may result in invaluable adjuncts to the treatment of ovarian cancer, with the ultimate goal of advancing patient care.

Health issues for menopausal women: the top 11 conditions have common solutions

Multiple health issues affect women throughout the life course differently from men, or do not affect men at all. Although attention to women's health is important in all stages in life, health among middle-aged and elderly women has not received sufficient attention by scientists and policy-makers. Related to the menopausal transition and the experiences accumulated until that age, many diseases occur or further develop in middle-aged and elderly women. To improve women's quality of life and guarantee a long-lasting and active role for middle-aged and elderly women in society, prevention of chronic diseases and disability is a key aspect. In this manuscript we give an overview of the major health issues for peri- and post-menopausal women, we summarize risk factors and interventions to improve menopausal health. Based on the available scientific literature and the global burden of disease endeavor, we have selected and herein describe the following top 11 key health issues, selected in terms of burden exerted in women's mortality, morbidity, disability and quality of life: cardiovascular disease, musculoskeletal disorders, cancer, cognitive decline and dementia, chronic obstructive pulmonary disease, diabetes mellitus, metabolic syndrome, depression, vasomotor symptoms, sleep disturbances and migraine.

Vitamin D suppresses leptin stimulation of cancer growth through microRNA

Obesity is a pandemic and major risk factor for cancers. The reduction of obesity would have been an effective strategy for cancer prevention, but the reality is that worldwide obesity has kept increasing for decades, remaining a major avoidable cancer risk secondary only to smoke. The present studies suggest that vitamin D may be an effective agent to reduce obesity-associated cancer risks in women. Molecular analyses showed that leptin increased human telomerase reverse transcriptase (hTERT) mRNA expression and cell growth through estrogen receptor-α (ERα) activation in ovarian cancer cells, which was suppressed by 1α,25-dihydroxyvitamin D3 [1,25(OH)2D3]. The suppression was compromised when miR-498 induction by the hormone was depleted with microRNA (miRNA) sponges. In mice, high-fat diet (HFD) stimulation of ovarian tumor growth was remarkably suppressed by 1,25(OH)2D3 analogue EB1089, which was also compromised by miR-498 sponges. EB1089 did not alter HFD-induced increase in serum leptin levels but increased miR-498 and decreased the diet-induced hTERT expression in tumors. Quantitative RT-PCR analyses revealed an inverse correlation between hTERT mRNA and miR-498 in response to 1,25(OH)2D3 in estrogen-sensitive ovarian, endometrial, and breast cancers. The studies suggest that miR-498-mediated hTERT downregulation is a key event mediating the anti-leptin activity of 1,25(OH)2D3 in estrogen-sensitive tumors in women.

Anthropometric factors and ovarian cancer risk: a systematic review and nonlinear dose-response meta-analysis of prospective studies

In the World Cancer Research Fund/American Institute for Cancer Research report from 2007 the evidence relating body fatness to ovarian cancer risk was considered inconclusive, while the evidence supported a probably causal relationship between adult attained height and increased risk. Several additional cohort studies have since been published, and therefore we conducted an updated meta-analysis of the evidence as part of the Continuous Update Project. We searched PubMed and several other databases up to 20th of August 2014. Summary relative risks (RRs) were calculated using a random effects model. The summary relative risk for a 5-U increment in BMI was 1.07 (95% CI: 1.03-1.11, I(2) = 54%, n = 28 studies). There was evidence of a nonlinear association, pnonlinearity  < 0.0001, with risk increasing significantly from BMI∼28 and above. The summary RR per 5 U increase in BMI in early adulthood was 1.12 (95% CI: 1.05-1.20, I(2) = 0%, pheterogeneity = 0.54, n = 6), per 5 kg increase in body weight was 1.03 (95% CI: 1.02-1.05, I(2) = 0%, n = 4) and per 10 cm increase in waist circumference was 1.06 (95% CI: 1.00-1.12, I(2) = 0%, n = 6). No association was found for weight gain, hip circumference or waist-to-hip ratio. The summary RR per 10 cm increase in height was 1.16 (95% CI: 1.11-1.21, I(2) = 32%, n = 16). In conclusion, greater body fatness as measured by body mass index and weight are positively associated risk of ovarian cancer, and in addition, greater height is associated with increased risk. Further studies are needed to clarify whether abdominal fatness and weight gain is associated with risk.

Body mass index and cancer incidence: the FINRISK study

The relation between body mass index (BMI) and risk of cancer incidence is controversial. Cancer incidence during 1972-2008 in relation to BMI was investigated in a prospective cohort of 54,725 Finns aged 24-74 years and free of cancer at enrollment. Over a mean follow-up of 20.6 years, 8,429 (15.4%) incident cancers were recorded, 4,208 (49.9%) from men. Both parametric and nonparametric approaches were used to evaluate the shape of the relationship between BMI and incidence of cancer. BMI had a linear positive association with incidence of cancers of the colon, liver, kidney, bladder and all sites combined in men, and of cancers of the stomach, colon, gallbladder and ovary in women, an inverse association with incidence of cancers of the lung in men and the lung and breast in women, a J-shaped association with incidence of all cancers combined in women. High BMI in women was associated with an increased overall cancer risk in never smokers but a reduced risk in smokers. Elevated BMI was associated with an increased risk of incidence of cancers of certain sites.

Genome-wide investigation of regional blood-based DNA methylation adjusted for complete blood counts implicates BNC2 in ovarian cancer

Due to its potential as a biomarker for early cancer detection, blood-based DNA methylation (DNAm) is of interest in cancer research. Specifically, highly predictive mechanisms for early detection of epithelial ovarian cancer (EOC) are desired, so previous studies have compared DNAm between EOC cases and controls. However, case-control studies are confounded by the distribution of white blood cell types through an immune response induced by the cancer. Rather than determining the distribution of the cell types manually or investigating isolated cell types, an alternative approach involves the use of complete blood count (CBC), which is routinely collected. In the analysis of an EOC case-control study of DNAm, we incorporate CBC measures to adjust for this confounding and compare DNAm between 242 EOC cases and 181 age-matched controls (assayed on the Illumina Infinium HumanMethylation27 or HumanMethylation450 Beadchips), at both the individual CpG and CpG island levels. We found that adjustment for leukocyte distribution using CBC measurements dramatically reduced confounding, with 62 single CpG sites found to be associated with EOC status after adjustment (P < 5E-8). Additionally, regional DNAm was assessed by applying principal components analysis to CpG islands. The top associated CpG island (P = 7E-6) was located in the promoter/transcription start site of the human basonuclin 2 gene (BNC2), a known susceptibility gene for EOC risk identified through GWAS. Follow-up studies are necessary to establish the role of BNC2 in blood-based DNA and EOC, including prospective studies to validate this region as a potential biomarker and predictor of EOC susceptibility.

Obesity increases tumor aggressiveness in a genetically engineered mouse model of serous ovarian cancer

OBJECTIVES

Obesity is associated with increased risk and worse outcomes for ovarian cancer. Thus, we examined the effects of obesity on ovarian cancer progression in a genetically engineered mouse model of serous ovarian cancer.

METHODS

We utilized a unique serous ovarian cancer mouse model that specifically deletes the tumor suppressor genes, Brca1 and p53, and inactivates the retinoblastoma (Rb) proteins in adult ovarian surface epithelial cells, via injection of an adenoviral vector expressing Cre (AdCre) into the ovarian bursa cavity of adult female mice (KpB mouse model). KpB mice were subjected to a 60% calories-derived from fat in a high fat diet (HFD) versus 10% calories from fat in a low fat diet (LFD) to mimic diet-induced obesity. Tumors were isolated at 6 months after AdCre injection and evaluated histologically. Untargeted metabolomic and gene expression profiling was performed to assess differences in the ovarian tumors from obese versus non-obese KpB mice.

RESULTS

At sacrifice, mice on the HFD (obese) were twice the weight of mice on the LFD (non-obese) (51g versus 31g, p=0.0003). Ovarian tumors were significantly larger in the obese versus non-obese mice (3.7cm(2) versus 1.2cm(2), p=0.0065). Gene expression and metabolomic profiling indicated statistically significant differences between the ovarian tumors from the obese versus non-obese mice, including metabolically relevant pathways.

What is the optimal treatment for obese patients with advanced ovarian carcinoma?

OBJECTIVE

The purpose of this study was to compare primary debulking surgery (PDS) vs neoadjuvant chemotherapy with interval debulking surgery (NACT-IDS) among obese patients.

STUDY DESIGN

Medical records of patients with a body mass index (BMI) of ≥30 kg/m(2) with ovarian/fallopian tube/primary peritoneal carcinoma between January 2005 and December 2010 were reviewed. Patients were separated by PDS or NACT-IDS. Preoperative characteristics, surgical procedures, and postoperative and oncologic outcomes were compared.

RESULTS

Of 117 patients, 95 women (81.2%) underwent PDS, and 22 women (18.8%) underwent NACT-IDS. Patients who underwent NACT-IDS were more likely to have stage IV disease (63.6% vs 26.3%; P = .001) and a low surgical complexity score (n = 14; 63.6%). There were no other differences between groups with respect to preoperative characteristics or postoperative morbidity. Compared with the NACT-IDS group, the PDS group had an improved progression-free survival (PFS; 15 vs 11 months; P = .006) and overall survival (OS; 53 vs 32 months; P = .036). Seventy-eight patients (66.7%) had a BMI of 30-34.9 kg/m(2). Within this subset of obese patients, the PDS group had an improved PFS (15 vs 10 months; P = .011) and OS (58 vs 32 months; P = .033), compared with the NACT-IDS group. Among patients with a BMI of ≥35 kg/m(2), there was no difference in PFS (14 vs 12 months; P = .316) or OS (38 vs 32 months; P = .640) when the PDS and NACT-IDS groups were compared.

CONCLUSION

Patients with a BMI of 30-34.9 kg/m(2) who undergo PDS have improved oncologic outcomes, compared with those women who undergo NACT-IDS. Patients with a BMI of ≥35 kg/m(2) who undergo PDS have similar oncologic outcomes to those who undergo NACT-IDS. Complication rates were similar at all BMIs, regardless of treatment approach.

HE4 transcription- and splice variants-specific expression in endometrial cancer and correlation with patient survival

We investigated the HE4 variant-specific expression patterns in various normal tissues as well as in normal and malignant endometrial tissues. The relationships between mRNA variants and age, body weight, or survival are analyzed. ICAT-labeled normal and endometrial cancer (EC) tissues were analyzed with multidimensional liquid chromatography followed by tandem mass spectrometry. Levels of HE4 mRNA variants were measured by real-time PCR. Mean mRNA levels were compared among 16 normal endometrial samples, 14 grade 1 and 14 grade 3 endometrioid EC, 15 papillary serous EC, and 14 normal human tissue samples. The relationship between levels of HE4 variants and EC patient characteristics was analyzed with the use of Pearson correlation test. We found that, although all five HE4 mRNA variants are detectable in normal tissue samples, their expression is highly tissue-specific, with epididymis, trachea, breast and endometrium containing the highest levels. HE4-V0, -V1, and -V3 are the most abundant variants in both normal and malignant tissues. All variants are significantly increased in both endometrioid and papillary serous EC, with higher levels observed in grade 3 endometrioid EC. In the EC group, HE4-V1, -V3, and -V4 levels inversely correlate with EC patient survival, whereas HE4-V0 levels positively correlate with age. HE4 variants exhibit tissue-specific expression, suggesting that each variant may exert distinct functions in normal and malignant cells. HE4 levels appear to correlate with EC patient survival in a variant-specific manner. When using HE4 as a biomarker for EC management, the effects of age should be considered.

Overweight, obesity and thyroid cancer risk: a meta-analysis of cohort studies

OBJECTIVE

This meta-analysis examined the relationship between excess body weight or body mass index (BMI) and risk of thyroid cancer.

METHODS

PubMed(®), MEDLINE(®), EMBASE™ and Academic Search™ Premier databases were searched to identify cohort studies examining the effect of being overweight or obese on the risk of thyroid cancer.

RESULTS

The inclusion criteria were met by seven cohort studies (total number of thyroid cancer cases, 5154). The pooled relative risk (RR) of thyroid cancer was 1.13 (95% confidence interval [CI] 1.04, 1.22) for overweight. Obesity was also linked with increased thyroid cancer risk in males and females, the strength of the association increasing with increasing BMI. The combined RR of thyroid cancer was 1.18 (95% CI 1.11, 1.25) for excess body weight (overweight and obesity combined). Being overweight was associated with a significant increase in thyroid cancer risk among non-Asians, but not among Asians. Overweight, obesity and excess body weight were all associated with papillary thyroid carcinoma risk.

CONCLUSIONS

The association between overweight/obesity/excess body weight and thyroid cancer risk was confirmed.

Hormonal risk factors and invasive epithelial ovarian cancer risk by parity

Background:

Recent studies have suggested that several ovarian cancer risk factors differ by parity status, but these findings have not been confirmed. We evaluated whether known risk factors of ovarian cancer differ between nulliparous and parous women using data from two large prospective cohorts.

Methods:

Data from the National Institutes of Health-AARP Diet and Health Study and the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial were combined for this analysis. Cox regression models were used to estimate associations with ovarian cancer risk. Risk heterogeneity by parity status was assessed using likelihood-ratio tests.

Results:

Among the 125 437 women included in the analysis, there were 16 589 (13%) nulliparous women and 108 848 (87%) parous women. Of the 623 women diagnosed with invasive epithelial ovarian cancer, 102 (16%) were nulliparous and 521 (84%) were parous. While parity reduced ovarian cancer risk, no differences were found for other risk factors by parity. Among ever users of hormone therapy, body mass index suggestively increased the risk of ovarian cancer by 1.5-fold in nulliparous but not parous women (P-heterogeneity=0.08).

Conclusion:

While nulliparous women have higher ovarian cancer risk than parous women, our findings suggest that the relative effects of most other risk factors do not differ by parity.

Expression of leptin receptor in endometrial biopsies of endometrial and ovarian cancer patients

The adipokine leptin plays a critical role in the regulation of reproductive function and there has been growing interest in its potential role in the development of cancers in which obesity is an established risk factor. Serum leptin levels were found to be higher in patients diagnosed with endometrial and ovarian cancer compared to those observed in healthy individuals. This study was conducted to determine the expression of the leptin receptor (Ob-R) in endometrial biopsies of patients diagnosed with endometrial and ovarian cancer. In this preliminary study, immunohistochemistry (IHC) and the color deconvolution method were used to assess the expression levels of the Ob-R protein in three groups of endometrial tissue: one from patients diagnosed with endometrioid endometrial carcinoma, one from patients diagnosed with ovarian cancer and one from individuals without any diagnosed gynecologic disease (control group). Our results demonstrated that the highest expression of Ob-R protein in endometrial biopsies was detected in the ovarian cancer group (P=0.000). This finding suggests that changes in Ob-R expression may be assessed through the measurement of the optical density of endometrial biopsies and may become a useful tool in preventive screening, particularly for ovarian cancer.

Why Has the BMI gone up so drastically in the last 35 years?

OBJECTIVES

We attempted to answer the following questions: Why has the body mass index (BMI) increased so dramatically in the last 35 years? Are some food groups or additives more responsible than others?

METHODS

Data for per capita food production available for consumption after spoilage for different food groups and additives from the US Department of Agriculture were used as independent variables to predict BMI increases. The heights and weights were taken from the Centers for Disease Control and the US Census Bureau for the years 1970 to 2004.

RESULTS

The additives of fats and sugars in combination, not separately, best predicted increases in BMI accounting for 97% of the variance in the linear regression analyses. When all food groups were entered into regressions to predict increases in BMI, fats and sugars in combination accounted for 96% of the variance for women and 97% for men, with the other food groups adding very little. Path analyses showed that fat and sweeteners had direct effects on BMI and were also the mediators of increased caloric consumption.

CONCLUSIONS

In line with the major physiological theories emphasizing palatability as the addictive stimulus in models of incentives and addiction, fats and sugars in combination rather than calories per se or particular food groups accounted for the increases in BMI. These empirically based theories and data suggest that one should focus on palatability and addictive models in dealing with the increasing problem of obesity in the United States.

Leptin stimulation of cell cycle and inhibition of apoptosis gene and protein expression in OVCAR-3 ovarian cancer cells

The OVCAR-3 cell line expressing the long (ObRb) and short (ObRt) isoforms of leptin receptor mRNA was used to analyze the effect of leptin on the expression of selected genes and proteins involved in the cell cycle and apoptosis. OVCAR-3 cells were exposed to 2, 20, 40, and 100 ng/ml of leptin. Cell proliferation was determined using the alamarBlue cell viability test and flow cytometry. Apoptosis was measured using a cellular DNA fragmentation ELISA kit. The expression of selected cell cycle and apoptosis genes was evaluated by real-time PCR and confirmed by western blot. The stimulatory action of leptin on cell proliferation was observed as an increase in cells in the S and G2/M phases. Up-regulation of genes responsible for inducing cell proliferation and suppression of genes responsible for inhibition of proliferation were noted. Western blots revealed increased expression of cyclins D and A and inhibition of p21WAF1/CIP1 protein expression by leptin. Inhibition of DNA fragmentation was observed under all leptin doses. Suppression of genes involved in the extrinsic and intrinsic apoptotic pathway was observed. Western blots illustrated decreased Bad, TNFR1, and caspase 6 protein expression in response to leptin treatment. Leptin promotes ovarian cancer cell line growth by up-regulating genes and proteins responsible for inducing cell proliferation as well as down-regulating pro-apoptotic genes and proteins in apoptotic pathways. Results of this study warrant examining the relationship between the risk of ovarian cancer and elevated leptin levels in obese women.

Fertility medications and the risk of cancer

Cancer is among the leading causes of death, and malignant diseases of the female genital tract are among the most common sites. Reproductive factors that are also associated with infertility have been identified as risk factors. Hormones are thought to play a role in the induction and promotion of some type of cancers. Hormonal preparations affect the endocrine milieu and, by acting on the reproductive organs themselves, could even have a direct effect on carcinogenesis. Numerous case-control and cohort studies have tried to determine whether fertility medication use increases cancer risk. Overall, the current data is reassuring but most research groups drew conclusions based on a small number of cases and after a relatively short follow-up. Proper counseling prior to fertility medication use is important and further studies on even larger patient groups with more cancer cases are needed to support widespread use of fertility medications.

Diabetes mellitus and ovarian cancer risk: a systematic review and meta-analysis of observational studies

OBJECTIVE

The objective of this study was to evaluate the epidemiologic association between diabetes and risk of ovarian cancer.

METHODS

We searched PubMed, EMBASE, and The Cochrane Library for observational studies on the association between diabetes and ovarian cancer. Cohort studies that reported relative risks (RRs) and case-control studies that showed odds ratios were included in the analysis. Summary RRs with 95% confidence intervals (CIs) were calculated with a random-effects model.

RESULTS

A total of 19 studies from 18 articles (7 case-control studies and 11 cohort studies) met the inclusion criteria. Combining data from all studies, diabetes was associated with an increased risk of ovarian cancer, compared with no diabetes (summary RR of ovarian cancer incidence, 1.17; 95% CI, 1.02-1.33). In cohort and nested case-control studies, patients with diabetes had statistically significant increased risk of ovarian cancer (RR, 1.16; 95% CI, 1.01-1.33), without significant heterogeneity (I = 27; P = 0.172). Among studies that control for age, body mass index, smoking, and alcohol, a prominent association between diabetes and ovarian cancer was found (RR, 1.55; 95% CI, 1.11-2.19).

CONCLUSIONS

This study suggests that women with diabetes have a moderately increased risk of ovarian cancer.

Leptin stimulates ovarian cancer cell growth and inhibits apoptosis by increasing cyclin D1 and Mcl-1 expression via the activation of the MEK/ERK1/2 and PI3K/Akt signaling pathways

Obesity is known to be an important risk factor for many types of cancer, such as breast, prostate, liver and endometrial cancer. Recently, epidemiological studies have indicated that obesity correlates with an increased risk of developing ovarian cancer, the most lethal gynecological cancer in developed countries. Leptin is predominantly produced by adipocytes and acts as a growth factor and serum leptin levels positively correlate with the amount of body fat. In this study, we investigated the effects of leptin on the growth of ovarian cancer cells and the underlying mechanism(s) of action. Our results showed that leptin stimulated the growth of the OVCAR-3 ovarian cancer cell line using MTT assay and trypan blue exclusion. Using western blot analysis, we found that leptin enhanced the expression of cyclin D1 and Mcl-1, which are important regulators of cell proliferation and the inhibition of apoptosis. To investigate the signaling pathways that mediate the effects of leptin, cells were treated with leptin plus specific inhibitors of JAK2, PI3K/Akt and MEK/ERK1/2 and analysis of the phosphorylation state of proteins was carried out by western blot assays. We showed that the activation of the MEK/ERK1/2 and PI3K/Akt signaling pathways were involved in the growth-stimulating effect of leptin on ovarian cancer cell growth and the specific inhibitors of PI3K/Akt and MEK/ERK1/2 revealed that these two pathways interacted with each other. Our data demonstrate that leptin upregulates the expression of cyclin D1 and Mcl-1 to stimulate cell growth by activating the PI3K/Akt and MEK/ERK1/2 pathways in ovarian cancer.

The upregulation of signal transducer and activator of transcription 5-dependent microRNA-182 and microRNA-96 promotes ovarian cancer cell proliferation by targeting forkhead box O3 upon leptin stimulation

Leptin overexpression contributes to the tumorigenesis of ovarian cancer. However, the functional mechanism and effects remain unclear. The aberrant expression of tumor-related microRNAs may play an important role in the development of cancer. In this report, we demonstrate that crosstalk between leptin and microRNA-182 and microRNA-96 affects the transformation and proliferation of ovarian cancer cells. Our results showed that leptin enhanced the colony formation of ovarian cancer cells in soft agar. A water-soluble tetrazolium salts assay revealed that leptin promoted ovarian cancer cell (SKOV3 and A2780 cells) proliferation in a time- and dose-dependent manner. The growth effects of leptin on ovarian cancer cells were mediated via the reduced expression of forkhead box O3 and its downstream targets p27 and Bim. We demonstrated that leptin upregulated miRNAs that target forkhead box O3 via luciferase reporter assay. Further examination indicated that only the inhibition of microRNA-182 and/or microRNA-96 rescued the expression of forkhead box O3 inhibited by leptin, and their mimics promoted the proliferation of ovarian cancer cells. Moreover, the signal transducer and activator of transcription 5 pathway, but not the signal transducer and activator of transcription 3 pathway, was implicated in the leptin-mediated expression of microRNA-182 and microRNA-96. In conclusion, our findings suggest that the upregulation of microRNA-182 and microRNA-96 targeting forkhead box O3 plays a significant role in the pro-proliferation effect of leptin on ovarian cancer cells, which might provide preliminary experimental clues for the development of new therapies against ovarian cancer.

Ovarian cancer and smoking: individual participant meta-analysis including 28,114 women with ovarian cancer from 51 epidemiological studies

Background

Smoking has been linked to mucinous ovarian cancer, but its effects on other ovarian cancer subtypes and on overall ovarian cancer risk are unclear, and the findings from most studies with relevant data are unpublished. To assess these associations, we review the published and unpublished evidence.

Methods

Eligible epidemiological studies were identified by electronic searches, review articles, and discussions with colleagues. Individual participant data for 28 114 women with and 94 942 without ovarian cancer from 51 epidemiological studies were analysed centrally, yielding adjusted relative risks (RRs) of ovarian cancer in smokers compared with never smokers.

Findings

After exclusion of studies with hospital controls, in which smoking could have affected recruitment, overall ovarian cancer incidence was only slightly increased in current smokers compared with women who had never smoked (RR 1·06, 95% CI 1·01–1·11, p=0·01). Of 17 641 epithelial cancers with specified histology, 2314 (13%) were mucinous, 2360 (13%) endometrioid, 969 (5%) clear-cell, and 9086 (52%) serous. Smoking-related risks varied substantially across these subtypes (p_{heterogeneity}<0·0001). For mucinous cancers, incidence was increased in current versus never smokers (1·79, 95% CI 1·60–2·00, p<0·0001), but the increase was mainly in borderline malignant rather than in fully malignant tumours (2·25, 95% CI 1·91–2·65 vs 1·49, 1·28–1·73; p_{heterogeneity}=0·01; almost half the mucinous tumours were only borderline malignant). Both endometrioid (0·81, 95% CI 0·72–0·92, p=0·001) and clear-cell ovarian cancer risks (0·80, 95% CI 0·65–0·97, p=0·03) were reduced in current smokers, and there was no significant association for serous ovarian cancers (0·99, 95% CI 0·93–1·06, p=0·8). These associations did not vary significantly by 13 sociodemographic and personal characteristics of women including their body-mass index, parity, and use of alcohol, oral contraceptives, and menopausal hormone therapy.

Interpretation

The excess of mucinous ovarian cancers in smokers, which is mainly of tumours of borderline malignancy, is roughly counterbalanced by the deficit of endometrioid and clear-cell ovarian cancers. The substantial variation in smoking-related risks by tumour subtype is important for understanding ovarian carcinogenesis.

Funding

Cancer Research UK and MRC.

Ovarian cancer: etiology, risk factors, and epidemiology

Little is known regarding the early aspects of ovarian carcinogenesis. As a consequence, the identification of women at risk for the disease is based primarily on clinical grounds, with family history being the most important risk factor. In this review, we will discuss the various hypotheses regarding ovarian etiology and pathogenesis. In addition, we will discuss the epidemiology of ovarian cancer, including hereditary, reproductive, hormonal, inflammatory, dietary, surgical, and geographic factors that influence ovarian cancer risk.

Mature breast adipocytes promote breast cancer cell motility

Adipocytes express substances involved in both normal physiology and pathological processes. One such adipocyte protein is the Serpin (serine protease inhibitor) plasminogen activator inhibitor-1 (PAI-1). PAI-1 functions to inhibit urokinase type plasminogen activator (uPA) though PAI-1 itself is also implicated in breast cancer progression. While the role of adipocytes in breast cancer development is not fully understood, obesity is a known risk factor associated with breast cancer. Thus, we characterized adipocytes from breast and omental tissues for PAI-1 and uPA, and the influence of adipocytes on breast cancer cell motility. Using preadipocyte cells from breast and omental adipose tissue, we differentiated each site into mature adipocytes. PAI-1 protein was found in breast adipocytes>omental preadipocytes>omental adipocytes>breast preadipocytes. Interestingly, uPA protein was not detected in any of these cell types. We then incubated breast adipocyte conditioned media (Adip-CM) and preadipocyte conditioned media (PreAdip-CM) on both normal (MCF-10A) and malignant (MCF-10CA1) breast epithelial cell lines. Adip-CM, but not PreAdip-CM, (a) increased cell motility in both MCF-10A and MCF-10CA1 cells; (b) increased cell-associated uPA activity in both cell lines; (c) increased phosphorylated-Akt levels in MCF-10CA1 cells; and (d) gene array profiles show altered expression of several genes associated with cancer adhesion, metastasis and signaling. Our results suggest that mature breast adipocytes are capable of altering the epithelial cell phenotype, producing a more motile cell type and further provide a potential link between obesity and risk of breast cancer.

American Cancer Society Guidelines on nutrition and physical activity for cancer prevention: reducing the risk of cancer with healthy food choices and physical activity

The American Cancer Society (ACS) publishes Nutrition and Physical Activity Guidelines to serve as a foundation for its communication, policy, and community strategies and, ultimately, to affect dietary and physical activity patterns among Americans. These Guidelines, published approximately every 5 years, are developed by a national panel of experts in cancer research, prevention, epidemiology, public health, and policy, and they reflect the most current scientific evidence related to dietary and activity patterns and cancer risk. The ACS Guidelines focus on recommendations for individual choices regarding diet and physical activity patterns, but those choices occur within a community context that either facilitates or creates barriers to healthy behaviors. Therefore, this committee presents recommendations for community action to accompany the 4 recommendations for individual choices to reduce cancer risk. These recommendations for community action recognize that a supportive social and physical environment is indispensable if individuals at all levels of society are to have genuine opportunities to choose healthy behaviors. The ACS Guidelines are consistent with guidelines from the American Heart Association and the American Diabetes Association for the prevention of coronary heart disease and diabetes, as well as for general health promotion, as defined by the 2010 Dietary Guidelines for Americans and the 2008 Physical Activity Guidelines for Americans.

Ovarian cancer and body size: individual participant meta-analysis including 25,157 women with ovarian cancer from 47 epidemiological studies

BACKGROUND

Only about half the studies that have collected information on the relevance of women's height and body mass index to their risk of developing ovarian cancer have published their results, and findings are inconsistent. Here, we bring together the worldwide evidence, published and unpublished, and describe these relationships.

METHODS AND FINDINGS

Individual data on 25,157 women with ovarian cancer and 81,311 women without ovarian cancer from 47 epidemiological studies were collected, checked, and analysed centrally. Adjusted relative risks of ovarian cancer were calculated, by height and by body mass index. Ovarian cancer risk increased significantly with height and with body mass index, except in studies using hospital controls. For other study designs, the relative risk of ovarian cancer per 5 cm increase in height was 1.07 (95% confidence interval [CI], 1.05-1.09; p<0.001); this relationship did not vary significantly by women's age, year of birth, education, age at menarche, parity, menopausal status, smoking, alcohol consumption, having had a hysterectomy, having first degree relatives with ovarian or breast cancer, use of oral contraceptives, or use of menopausal hormone therapy. For body mass index, there was significant heterogeneity (p<0.001) in the findings between ever-users and never-users of menopausal hormone therapy, but not by the 11 other factors listed above. The relative risk for ovarian cancer per 5 kg/m(2) increase in body mass index was 1.10 (95% CI, 1.07-1.13; p<0.001) in never-users and 0.95 (95% CI, 0.92-0.99; p=0.02) in ever-users of hormone therapy.

CONCLUSIONS

Ovarian cancer is associated with height and, among never-users of hormone therapy, with body mass index. In high-income countries, both height and body mass index have been increasing in birth cohorts now developing the disease. If all other relevant factors had remained constant, then these increases in height and weight would be associated with a 3% increase in ovarian cancer incidence per decade. Please see later in the article for the Editors' Summary.

The epidemiology of endometrial and ovarian cancer

This review highlights similarities in the epidemiology of endometrial and ovarian cancer, including highly correlated incidence rates and similar risk factor profiles. Factors that decrease risk for both cancers include a late menarche, early age at first birth, giving birth and breastfeeding, and use of oral contraceptives. Short or irregular cycles and late menopause are associated with increased risk for both. Other risk factors that appear to operate in a similar direction include decreased risk associated with IUD use or a tubal ligation, and increased risk associated with obesity, lack of exercise, and use of talc powders in genital hygiene. Estrogen excess is proposed as the underlying mechanism for most endometrial cancers, whereas incessant ovulation has been suggested as the explanation for ovarian cancer. However, an increased number of estimated ovulatory cycles correlates directly with risk for both endometrial and ovarian cancer, suggesting that reproductive tissue turnover with an accumulation of PTEN or p53 mutations represents a possible common mechanism. An immune-based explanation involving mucin proteins represents another common mechanism that could explain additional risk factors. Maintenance of ideal weight, breastfeeding children, use of oral contraceptives, and avoidance of talc powders in genital hygiene are measures that could lower the risk for both types of cancer. Careful selection of patients for prophylactic oophorectomy for those women who are coming to hysterectomy for benign disease is an additional measure to consider for ovarian cancer.

Interpreting the epidemiological evidence linking obesity and cancer: A framework for population-attributable risk estimations in Europe

Standard approaches to estimating population-attributable risk (PAR) include modelling estimates of exposure prevalence and relative risk. Here, we examine the associations between body mass index (BMI) and cancer risk and how effect modifications of these associations impact on PAR estimates. In 2008, sex- and population-specific risk estimates were determined for associations with BMI in a standardised meta-analysis for 20 cancer types. Since then, refinements of these estimates have emerged: (i) absence of menopausal hormonal therapy (MHT) is associated with elevated BMI associations in post-menopausal breast, endometrial and ovarian cancers; (ii) current smoking attenuates the BMI associations in oesophageal squamous cell carcinoma, lung and pancreatic cancers; (iii) prostate screening attenuates BMI associations when all prostate cancers are considered together; and (iv) BMI is differentially associated with different histological subtypes within the same cancer group. Using secondary analyses of the aforementioned meta-analysis, we show 2-3-fold shifts in PAR estimations for breast and endometrial cancers depending on the MHT usage in European countries. We also critically examine how to best handle exposures (in this example, BMI distributions) and relative risk estimates in PAR models, and argue in favour of a counterfactual approach based around BMI means. From these observations, we develop a research framework in which to optimally evaluate future trends in numbers of new cancers attributable to excess BMI. Overall, this framework gives conservative estimates for PAR - nonetheless, the numbers of avoidable cancers across Europe through avoidance of excess weight are substantial.

Estrogen receptor alpha pathway is involved in leptin-induced ovarian cancer cell growth

Previously, we demonstrated that leptin, a pleiotropic hormone produced by adipocytes, stimulates the growth of BG-1 ovarian cancer cells via the extracellular signal-regulated kinase signaling pathway. In this study, we further investigated the involvement of estrogen receptor (ER) pathway in the mechanism of leptin-induced ovarian cancer cell growth. Treatment with leptin (100 ng/ml) resulted in a significant increase in the cell growth of ERα-transfected OVCAR-3 and A2780 cells, whereas no significant difference was observed in ERβ-transfected cells. Downregulation of ERα using small interfering RNA completely reversed leptin-induced growth of BG-1 cells. Treatment with leptin resulted in ER transcriptional activation, i.e. nuclear localization of ER and increased expression of pS2, an estrogen-dependent gene. Luciferase reporter assay revealed that treatment of BG-1 cells with leptin (100 ng/ml) stimulated the expression of the reporter gene in the absence of estradiol (E2). To examine an involvement of Janus kinase 2/signal transducers and activators of transcription 3 (STAT-3) and phosphatidyl-inositol 3-kinase (PI3K)/Akt in leptin-induced pathway, we demonstrated that leptin increased phosphorylation of STAT-3 and Akt in BG-1 cells in a time- and dose-dependent manner. On the other hand, leptin-induced cell growth and ER transactivation were effectively blocked by specific STAT-3 inhibitor AG490 and, to a lesser extent, by PI3K inhibition. Further study with coimmunoprecipitation assay revealed that stimulation with leptin induced STAT-3 binding to ERα. Taken together, these results indicate that the stimulation of ovarian cancer cell growth by leptin involves, at least in part, ER transcriptional activation via the STAT-3 signaling pathways.

Body size and the risk of ovarian cancer by hormone therapy use in the California Teachers Study cohort

OBJECTIVE

To investigate whether obesity and hormone therapy (HT) are associated with ovarian cancer risk among women in the California Teachers Study cohort.

METHODS

Of 56,091 women age ≥ 45 years, 277 developed epithelial ovarian cancer between 1995 and 2007. Multivariate Cox regression was performed.

RESULTS

Among women who never used HT, greater adult weight gain, waist circumference and waist-to-height ratio, but not adult BMI, increased risk of ovarian cancer. Compared to women who never used HT and had a stable adult weight, risk of ovarian cancer was increased in women who gained ≥ 40 lb (relative risk (RR) 1.8, 95% confidence interval (CI): 1.0-3.0) or used HT for >5 years (RR 2.3 95% CI: 1.3-4.1). Having both exposures (RR 1.9, 95% CI: 0.99-3.5), however, did not increase risk more than having either alone. Results were similar for waist circumference and weight-to-height ratio; however, differences across HT groups were not statistically significant.

CONCLUSIONS

This study suggests that abdominal adiposity and weight gain, but not overall obesity, increase ovarian cancer risk and that there may be a threshold level beyond which additional hormones, whether exogenous or endogenous, do not result in additional elevation in risk. However, large pooled analyses are needed to confirm these findings.

Identifying the Causes of Cancer Health Disparities: Biologic and Non Biologic Determinants

The causes of cancer health disparities amongst Pacific Islanders and other racial groups are complex and multifactorial. Both biologic and non biologic determinants have been identified as causal factors. Racial/ethnic classification can be used as a surrogate for non biologic determinants such as place of geographic origin, socioeconomic status, cultural practices, and diet. Given that non biologic and biologic determinants are not mutually exclusive, using racial/ethnic classification may be hypothesis generating and assist in the identification of biologic determinants such as infections, toxins, and/or environmental exposures that lead to carcinogenesis. This commentary provides several examples of cancer specific biologic determinants that may lead to cancer health disparities. It also discusses specific non biologic determinants of cancer health disparities that must be overcome in order to increase participation of underserved populations in clinical trial research. Taken together, these examples demonstrate the need to further our understanding of the determinants of cancer health disparities that can lead to the enactment of preventive measures and/or targeted therapies.

Pre- and post-diagnosis body mass index, weight change, and ovarian cancer mortality

OBJECTIVE

The purpose of this study was (1) to investigate the association between BMI self-reported at three time points (during their 20s, 5 years before diagnosis, and post-diagnosis) and mortality among 388 women with newly diagnosed epithelial ovarian cancer and (2) weight change between these 3 time points and mortality.

METHODS

Women completed interview-administered questionnaires on average 9 months post-diagnosis. Women were followed 5 years after diagnosis or until death, whichever came first. Cox proportional hazard regression was used to estimate associations between BMI during the 20s, BMI 5 years prior to diagnosis, BMI post-diagnosis (i.e., at the time of interview) and weight changes between these time points and mortality.

RESULTS

The 5-year survival rate was 54% (178 deaths, 146 from ovarian cancer). BMI measured continuously at all three time points was associated with a higher risk of ovarian cancer mortality (P≤0.05). The strongest association was observed with BMI in the 20s and all-cause mortality comparing women with BMI≥25 kg/m(2) to BMI<25 kg/m(2) (HR=1.82; 95% CI, 1.02-3.27; P for trend=0.045). For weight change from the 20s to 5 years prior to diagnosis and ovarian cancer specific mortality, we observed a 68% higher risk of ovarian cancer mortality (HR=1.68; 95% CI, 1.11-2.55; P for trend=0.015, comparing women with <10 lbs weight gain to women with ≥10 lbs weight gain).

CONCLUSION

BMI prior to and after diagnosis and weight gain throughout adulthood is associated with ovarian cancer mortality.

Anthropometric measures and epithelial ovarian cancer risk in the European Prospective Investigation into Cancer and Nutrition

We examined the associations of measured anthropometric factors, including general and central adiposity and height, with ovarian cancer risk. We also investigated these associations by menopausal status and for specific histological subtypes. Among 226,798 women in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, there were 611 incident cases of primary, malignant, epithelial ovarian cancer diagnosed during a mean 8.9 years of follow-up. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs), adjusted for potential confounders. Compared to women with body mass index (BMI) < 25 kg/m2, obesity (BMI > or = 30 kg/m2) was associated with excess ovarian cancer risk for all women combined (HR = 1.33, 95% CI = 1.05-1.68; p(trend) = 0.02) and postmenopausal women (HR = 1.59, 95% CI = 1.20-2.10; p(trend) = 0.001), but the association was weaker for premenopausal women (HR = 1.16, 95% CI = 0.65-2.06; p(trend) = 0.65). Neither height or weight gain, nor BMI-adjusted measures of fat distribution assessed by waist circumference, waist-hip ratio (WHR) or hip circumference were associated with overall risk. WHR was related to increased risk of mucinous tumors (BMI-adjusted HR per 0.05 unit increment = 1.17, 95% CI = 1.00-1.38). For all women combined, no other significant associations with risk were observed for specific histological subtypes. This large, prospective study provides evidence that obesity is an important modifiable risk factor for epithelial ovarian cancer, particularly among postmenopausal women.

Decreased severity of ovarian cancer and increased survival in hens fed a flaxseed-enriched diet for 1 year

OBJECTIVE

With the exception of the laying hen, no other animal model of spontaneous ovarian surface epithelial cancer replicates the human disease. Flaxseed is the richest vegetable source of omega-3 fatty acids, which are chemopreventive in breast cancer and may be important in other cancers. The objective of this study was to determine if a flaxseed-enriched diet had a chemopreventive effect on ovarian cancer in the laying hen.

METHODS

White Leghorn hens were fed with 10% flaxseed-enriched or standard diet for 1 year. The incidence and severity of ovarian cancer were determined by gross pathology and histology in the two groups. General health markers were also measured. Eggs were collected and analyzed by gas chromatography to determine omega-3 fatty acid levels.

RESULTS

A significant reduction in late stage ovarian tumors was detected in the flaxseed-fed hens. Incidence rates of ovarian cancer were not significantly different between the two groups. The results indicate that a flaxseed diet increases overall survival in the laying hen. Flaxseed-fed hens' eggs incorporated significantly more omega-3 fatty acids compared to control hens.

CONCLUSIONS

These findings show that 10% flaxseed supplementation for 1 year in the laying hen results in a significant reduction in the severity of ovarian cancer, but no change in the incidence of the disease. Hens fed flaxseed had overall better health and reduced mortality. These findings may provide the basis for a clinical trial that evaluates the efficacy of flaxseed as a chemosuppressant of ovarian cancer in women.

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.

HE4 as a biomarker for ovarian and endometrial cancer management

Ovarian and endometrial cancer will be diagnosed in over 63,000 women in 2009, resulting in 22,000 deaths in the USA. Histologic screening, such as pap smears for detection of cervical cancer, is not feasible for these diseases given difficulty with access to the tissue. Thus, a serum- screening test using a biomarker or panel of biomarkers would be useful to aid in cancer diagnosis, detection of recurrence and as a means to monitor response to therapy. In this review, we focus on the human epididymis protein (HE)4 gene, which appears to have potential as a biomarker for both of these diseases. The structure and methods of detection of HE4 are discussed. Preliminary data show that HE4 may have more potential than cancer antigen 125 in discriminating benign from cancerous ovarian masses, and has the strongest correlation with endometrial cancer of all markers tested to date. Utilizing risk stratification, a panel of biomarkers including HE4 may ultimately be useful for detecting ovarian and endometrial cancer at an early stage in patients at high risk.

Overexpression of leptin receptor predicts an unfavorable outcome in Middle Eastern ovarian cancer

Background

Recent epidemiological studies have suggested that obesity is associated with ovarian cancer. Obesity hormone leptin and its receptor (Ob-R) contribute to tumor development by enhancing cell growth and survival. This study was design to investigate the prevalence of leptin and Ob-R in Middle Eastern epithelial ovarian cancer (EOC) and to analyze the role of leptin and the mechanisms under its action in EOC tissue sample and cell lines.

Methods

The expression of leptin and Ob-R was examined by immunohistochemistry in a tissue microarray of 156 EOC samples. Proliferation of EOC cells in response to leptin was assessed by MTT assays, and its anti-apoptotic effects were determined by flow cytometry. Effect of leptin on PI3K/AKT signaling pathway was further determined by western blotting.

Results

In clinical samples, Ob-R overexpression was seen in 59.2% EOCs and was significantly associated with poor progression free survival (p = 0.0032). Furthermore, Ob-R expression was associated with anti apoptotic proteins Bcl-XL (p = 0.0035) and XIAP (p = 0.0001). In vitro analysis using EOC cell lines showed that leptin stimulated cell proliferation and inhibits apoptosis via activation of PI3K/AKT signaling pathway. Inhibition of PI3K activity by LY294002, a specific inhibitor of PI3-kinase abrogated leptin mediated PI3K/AKT signaling. Gene silencing of Ob-R with Ob-R siRNA in EOC cells resulted in down regulation of phospho-AKT and its down stream targets.

Conclusion

Our findings have potential clinical implication for EOC development and progression.

Ovarian cancer risk factors in African-American and white women

Ovarian cancer is the most lethal gynecologic malignancy in both African-American and white women. Although prevalences of many ovarian cancer risk factors differ markedly between African Americans and whites, there has been little research on how the relative contributions of risk factors may vary between racial/ethnic groups. Using data from a North Carolina case-control study (1999-2008), the authors conducted unconditional logistic regression analyses to calculate odds ratios and 95% confidence intervals for ovarian cancer risk factors in African-American (143 cases, 189 controls) and white (943 cases, 868 controls) women and to test for interactions by race/ethnicity. They also calculated attributable fractions within each racial/ethnic group for the modifiable factors of pregnancy, oral contraceptive use, tubal ligation, and body mass index. Many risk factors showed similar relations across racial/ethnic groups, but tubal ligation and family history of breast or ovarian cancer showed stronger associations among African Americans. Younger age at menarche was associated with risk only in white women. Attributable fractions associated with tubal ligation, oral contraceptive use, and obesity were markedly higher for African Americans. The relative importance of ovarian cancer risk factors may differ for African-American women, but conclusions were limited by the small sample. There is a clear need for further research on etiologic factors for ovarian cancer in African-American women.

Epidemiologic correlates of ovarian cortical inclusion cysts (CICs) support a dual precursor pathway to pelvic epithelial cancer

OBJECTIVE

Many ovarian carcinomas are presumed to arise within ovarian cortical inclusion cysts (CICs). This study examined the frequency of ovarian CICs in relation to epidemiologic risk factors in women with BRCA1 and BRCA2 (BRCA+) mutations.

METHODS

BRCA+ women who underwent risk-reducing bilateral salpingo-oophorectomy were studied (n=74). Fifteen demographic variables (e.g., age at time of surgery, age at first birth, age at menopause, body mass index (BMI), gravidity) from a review of the medical records and three pathologic variables (cystic and atretic follicles, corpora lutea) were recorded. Statistical associations were made using T-test or Chi Square analysis and logistic regression analysis for p-trend.

RESULTS

Women whose ovaries contained 7 for more CICs were older at first birth (p=0.034), surgery (p=0.059), menopause (p=0.046) and had a higher BMI (p=0.034) than those with <7 CICs. Regression analysis revealed a significant association between CICs and increasing BMI (p=0.01).

CONCLUSIONS

CICs correlate with greater body mass index, similar to low-grade serous and endometrioid tumors and in contrast to high-grade serous carcinoma and its putative precursor in the fallopian tube. A model is presented for ovarian and tubal pathways to pelvic cancer that are linked to different microscopic precursors with distinct epidemiologic correlates.

Overweight, obesity and gastric cancer risk: results from a meta-analysis of cohort studies

The relationship between excess body weight and gastric cancer risk has not been well studied to date. We therefore carried out a systematic review and meta-analysis of published cohort studies to evaluate the association between excess body weight and gastric cancer risk. An electronic search of the MEDLINE, PubMed, EMBASE and Academic Search Premier (EBSCO) databases, which contain articles published from 1950 onwards, was conducted in order to select studies for this meta-analysis. Ten studies with a total number of 9492 gastric cancer cases and a studied population of 3,097,794 were identified. Overall, excess body weight [body mass index (BMI)25] was associated with an increased risk of gastric cancer [odds ratio (OR)=1.22; 95% confidence intervals (CIs)=1.06-1.41]. Specifically, a stratified analysis showed that excess body weight was associated with an increased risk of cardia gastric cancer [overweight and obese (BMI 25), OR=1.55, 95% CIs=1.31-1.84] and gastric cancer among non-Asians (overweight and obese, OR=1.24, 95% CIs=1.14-1.36); however, the stratified analysis also showed that there was no statistically significant link between excess body weight and gastric cancer in the following subgroups: males (overweight and obese, OR=1.22, 95% CIs=0.96-1.55), females (overweight and obese, OR=1.13, 95% CIs=0.65-1.94), non-cardia gastric cancer (overweight and obese, OR=1.18, 95% CIs=0.96-1.45) and Asians (overweight and obese, OR=1.17, 95% CIs=0.88-1.56). The combined results of this meta-analysis, however, do indicate that overweight and obesity are associated with an increased risk of gastric cancer. The strength of the association also increases with increasing BMI.