Body mass index effects on risk of ovarian cancer: a meta- analysis

Racial differences in the association of body mass index and ovarian cancer risk in the OCWAA Consortium

BACKGROUND

Obesity disproportionately affects African American (AA) women and has been shown to increase ovarian cancer risk, with some suggestions that the association may differ by race.

METHODS

We evaluated body mass index (BMI) and invasive epithelial ovarian cancer (EOC) risk in a pooled study of case-control and nested case-control studies including AA and White women. We evaluated both young adult and recent BMI (within the last 5 years). Associations were estimated using multi-level and multinomial logistic regression models.

RESULTS

The sample included 1078 AA cases, 2582 AA controls, 3240 White cases and 9851 White controls. We observed a higher risk for the non-high-grade serous (NHGS) histotypes for AA women with obesity (ORBMI 30+= 1.62, 95% CI: 1.16, 2.26) and White women with obesity (ORBMI 30+= 1.20, 95% CI: 1.02, 2.42) compared to non-obese. Obesity was associated with higher NHGS risk in White women who never used HT (ORBMI 30+= 1.40, 95% CI: 1.08, 1.82). Higher NHGS ovarian cancer risk was observed for AA women who ever used HT (ORBMI 30+= 2.66, 95% CI: 1.15, 6.13), while in White women, there was an inverse association between recent BMI and risk of EOC and HGS in ever-HT users (EOC ORBMI 30+= 0.81, 95% CI: 0.69, 0.95, HGS ORBMI 30+= 0.73, 95% CI: 0.61, 0.88).

CONCLUSION

Obesity contributes to NHGS EOC risk in AA and White women, but risk across racial groups studied differs by HT use and histotype.

Risk Factors for Ovarian Cancer: An Umbrella Review of the Literature

Several non-genetic factors have been associated with ovarian cancer incidence or mortality. To evaluate the strength and validity of the evidence we conducted an umbrella review of the literature that included systematic reviews/meta-analyses that evaluated the link between non-genetic risk factors and ovarian cancer incidence and mortality. We searched PubMed, EMBASE, Cochrane Database of Systematic Reviews and performed a manual screening of references. Evidence was graded into strong, highly suggestive, suggestive or weak based on statistical significance of the random effects summary estimate and the largest study in a meta-analysis, the number of cases, between-study heterogeneity, 95% prediction intervals, small study effects, and presence of excess significance bias. We identified 212 meta-analyses, investigating 55 non-genetic risk factors for ovarian cancer. Risk factors were grouped in eight broad categories: anthropometric indices, dietary intake, physical activity, pre-existing medical conditions, past drug history, biochemical markers, past gynaecological history and smoking. Of the 174 meta-analyses of cohort studies assessing 44 factors, six associations were graded with strong evidence. Greater height (RR per 10 cm 1.16, 95% confidence interval (CI) 1.11-1.20), body mass index (BMI) (RR ≥ 30 kg/m2 versus normal 1.27, 95% CI 1.17-1.38) and three exposures of varying preparations and usage related to hormone replacement therapy (HRT) use increased the risk of developing ovarian cancer. Use of oral contraceptive pill reduced the risk (RR 0.74, 95% CI 0.69-0.80). Refining the significance of genuine risk factors for the development of ovarian cancer may potentially increase awareness in women at risk, aid prevention and early detection.

Metabolic risk factors of ovarian cancer: a review

Ovarian cancer continues to be the leading cause of death from gynecological cancers. Despite inconsistent results, patients with metabolic abnormalities, including obesity and diabetes mellitus (DM), have poorer outcomes, showing a correlation with ovarian cancer incidence and ovarian cancer survival. Since ovarian cancer is the most common cancer in women, and considering the increasing prevalence of obesity and DM, this paper reviews the literature regarding the relationship between the aforementioned metabolic derangements and ovarian cancer, with a focus on ovarian cancer incidence, mortality, and likely mechanisms behind them. Several systematic reviews and meta-analyses have shown that obesity is associated with a higher incidence and poorer survival in ovarian cancer. Although more studies are required to investigate the etiological relation of DM and ovarian cancer, sufficient biological evidence indicates poorer outcomes and shorter survival in DM women with ovarian cancer. A variety of pathologic factors may contribute to ovarian cancer risk, development, and survival, including altered adipokine expression, increased levels of circulating growth factors, altered levels of sex hormones, insulin resistance, hyperinsulinemia, and chronic inflammation. Thus, obesity and DM, as changeable risk factors, can be targeted for intervention to prevent ovarian cancer and improve its outcomes.

Risk of primary lung cancer after breast cancer radiotherapy: a systematic review and meta-analysis

BACKGROUND

Epidemiological studies have shown that the risk of secondary malignancies may increase by radiotherapy. Lung cancer is the most important long-term complication of breast cancer radiotherapy.

METHODS

Major electronic databases including Scopus, Web of Science, and MEDLINE were searched. All cohort studies that investigated the association between radiotherapy for breast cancer and risk of primary lung, bronchus, and trachea cancers conducted until March 2021 were included. The study participants were evaluated regardless of their age and ethnicity. The Newcastle-Ottawa Scale was used to assess the quality of the studies. The designated effects were risk ratio (RR). The random-effects model was used to estimate the average effects.

RESULTS

Fifteen studies including 1,640,247 women with primary breast cancer were identified of which 937,151 had not received radiotherapy and 703,096 subjects had received radiotherapy. In general, there was no significant association between breast cancer radiotherapy and lung cancer based on 10 studies (RR = 0.95, 95% CI 0.87-1.02, P = 0.15), There was no association between breast cancer radiotherapy and lung, bronchus, and trachea cancers either based on 5 studies (RR = 0.98, 95% CI 0.93-1.02, P = 0.32).

CONCLUSION

Radiotherapy for breast cancer is not associated with an excess risk of lung cancer. Due to the limited number of studies, lack of data regarding smoking status, and substantial variation in exposure of the lungs in breast cancer radiotherapy worldwide, further investigations based on randomized controlled trials are suggested to address the potential risk of lung cancer after breast cancer radiotherapy.

Factors for the Primary Prevention of Breast Cancer: A Meta-Analysis of Prospective Cohort Studies

Background: This report provided the effect of 15 preventable factors on the risk of breast cancer incidence.

Study design: A systematic review and meta-analysis.

Methods: A detailed research was conducted on PubMed, Web of Science, and Scopus databases in January 2020. Reference lists were also screened. Prospective cohort studies addressing the associations between breast cancer and 15 factors were analyzed. Between-study heterogeneity was investigated using the χ², τ², and I² statistics. The probability of publication bias was explored using the Begg and Egger tests and trim-and-fill analysis. Effect sizes were expressed as risk ratios (RRs) with 95% confidence intervals (CIs) using a random-effects model.

Results: Based on the results, out of 147,083 identified studies, 197 were eligible, including 19,413,702 participants. The RRs (95% CI) of factors associated with breast cancer were as follows: cigarette smoking 1.07 (1.05, 1.09); alcohol drinking 1.10 (1.07, 1.12); sufficient physical activity 0.90 (0.86, 0.95); overweight/obesity in premenopausal 0.92 (0.82, 1.03) and postmenopausal 1.18 (1.13, 1.24); nulliparity 1.16 (1.03, 1.31); late pregnancy 1.37 (1.25, 1.50); breastfeeding 0.87 (0.81, 0.93); ever using oral contraceptive 1.00 (0.96, 1.05); ever using estrogen 1.13 (1.04, 1.23); ever using progesterone 1.02 (0.84, 1.24); ever using estrogen/progesterone 1.60 (1.42, 1.80); ever taking hormone replacement therapy 1.26 (1.20, 1.32); red meat consumption 1.05 (1.00, 1.11); fruit/vegetable consumption 0.87 (0.83, 0.90); and history of radiation therapy, based on single study 1.31 (0.87, 1.98).

Conclusions: This meta-analysis provided a clear picture of several factors associated with the development of breast cancer. Moreover, the useful information in this study may be utilized for ranking and prioritizing preventable risk factors to implement effective prevention programs.

Worldwide incidence and mortality of ovarian cancer and Human Development Index (HDI): GLOBOCAN sources and methods 2018

Objective

Ovarian cancer is known as the seventh most common cancer among women, accounting for about 4% of all cancers associated with the females.

Method

This is a descriptive cross-sectional study based on cancer incidence data and cancer mortality rates from the Global Cancer Data in 2018. The incidence and mortality rates were estimated and ovarian cancer distribution maps for world countries were drawn. To analyze data, correlation and regression tests were used to evaluate association between its incidence and mortality with human development index (HDI)

Results

Results revealed a direct and significant correlation between ovarian cancer incidence (R = 0.409, P < 0.0001) and mortality (R = 0.193, P < 0.05) with HDI. It also projected a direct and significant correlation between incidence with Gross National Income per 1,000 capita (GNI), mean years of schooling (MYS), life expectancy at birth (LEB) and expected years of schooling (EYS) (P < 0.0001). The findings also demonstrated a direct and significant correlation between mortality and GNI, MYS, LEB as well as EYS (P < 0.05). The linear regression model showed that a higher MYS [B = 0.2, CI 95%: (-0.03, 0.5)] can significantly augment the incidence of ovarian cancer while an increased MYS [B = 0.2, CI 95% (0.03, 0.4)] can induce mortality.

Conclusions

Given the direct and significant correlation between ovarian cancer incidence and mortality with HDI, attention to risk factors in these countries can be effective in curbing its incidence and mortality.

Pre-pregnancy obesity and childhood malignancies: A population-based cohort study

OBJECTIVE

Exploring the effect of maternal obesity during pregnancy on the long-term health of offspring is of great importance. The aim of this study was to evaluate the association between maternal pre-pregnancy obesity and future risk of childhood malignancies.

STUDY DESIGN

A population-based cohort analysis comparing the risk for long-term childhood malignancies (up to the age of 18 years) in children born (1991-2014) to mothers with and without pre-pregnancy obesity (body mass index > 30) was conducted in July 2017. Childhood malignancies were predefined based on ICD-9 codes, as recorded in the hospital medical files. Children with congenital malformations and multiple gestations were excluded from the analysis. The Kaplan-Meier survival curve was constructed to compare cumulative oncological morbidity in both groups over time. The Cox proportional hazards model was used to control for confounders.

RESULTS

During the study period, 241 273 infants met the inclusion criteria; 3268 were born to mothers with pre-pregnancy obesity. Children of obese women had significantly increased risk for several childhood malignancies (including brain tumors) as well as increased risk for total hospitalizations with malignancy diagnoses, even after controlling for several confounders (adjusted HR 1.90, 95% CI 1.07-3.37, P = 0.028). Cumulative incidence of oncological morbidity was also significantly increased over time in the studied group (log-rank P = 0.023).

CONCLUSION

Maternal pre-pregnancy obesity is significantly associated with an increased long-term risk for general childhood malignancies, and specifically brain tumors in the offspring. These results are important when counseling mothers regarding potential future risks and recommended lifestyle modifications.

Weight Loss and Changes in Adipose Tissue and Skeletal Muscle Volume after Laparoscopic Sleeve Gastrectomy and Roux-en-Y Gastric Bypass: a Prospective Study with 12-Month Follow-Up

BACKGROUND

This study aimed to evaluate changes in body tissue composition with obesity surgery regarding visceral fat, subcutaneous fat, and skeletal muscle.

DESIGN

Prospective non-randomized single-center cohort study METHODS: Whole-body magnetic resonance imaging (MRI) measured volumes of subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), and skeletal muscle (SM) in 31 patients with laparoscopic sleeve gastrectomy (LSG, 20) or Roux-en-Y gastric bypass (RYGB, 11) preoperatively, at three- and 12-months follow-up.

RESULTS

Body mass index (BMI) went down from 45.2 ± 6.5 preoperatively to 37.2 ± 5.6 (p < 0.001) at three months and 32.2 ± 5.3 kg/m² (p < 0.001) at 12 months. SAT went down from 55.0 ± 14.0 L (liter) to 42.2 ± 13.3 L (p < 0.001) at three months and 31.7 ± 10.5 L (p < 0.001) at 12 months (- 42.3%). VAT went down from 6.5 ± 2.3 to 4.5 ± 1.7 (p < 0.001) at three months and 3.1 ± 1.7 L (p < 0.001) at 12 months (- 52.3%). SM went down from 22.7 ± 4.8 to 20.4 ± 3.6 (p = 0.008) at three months and remained 20.2 ± 4.6 L at 12 months (p = 0.17 relative three-month; p = 0.04 relative preop, - 11.1%). Relative loss was higher for VAT than that for SAT (52.3 ± 18.2% vs. 42.3 ± 13.8%; p = 0.03). At 12 months, there was no difference between LSG and RYGB for relative changes in BMI or body tissue composition.

CONCLUSION

Postoperatively, there was higher net loss of SAT but higher relative loss of VAT with weight loss. SM was lost only during the first three months. MRI provides accurate evaluation of surgeries' effect on individual patients' tissue composition. This can benefit risk assessment for related cardiovascular and metabolic health but cost-related factors will likely reserve the used methods for research.

Obesity-Induced Peritoneal Dissemination of Ovarian Cancer and Dominant Recruitment of Macrophages in Ascites

One-fifth of cancer deaths are associated with obesity. Because the molecular mechanisms by which obesity affects the progression of ovarian cancer (OC) are poorly understood, we investigated if obesity could promote the progression of OC cells using the postmenopausal ob/ob mouse model and peritoneal dissemination of mouse ID8 OC cells. Compared to lean mice, obese mice had earlier OC occurrence, greater metastasis throughout the peritoneal cavity, a trend toward shorter survival, and higher circulating glucose and proinflammatory chemokine CXCL1 levels. Ascites in obese mice had higher levels of macrophages (Mφ) and chemokines including CCL2, CXCL12, CXCL13, G-CSF and M-CSF. Omental tumor tissues in obese mice had more adipocytes than lean mice. Our data suggest that obesity may accelerate the peritoneal dissemination of OC through higher production of pro-inflammatory chemokines and Mφ recruitment.

An Overview on the Anticancer Activity of Azadirachta indica (Neem) in Gynecological Cancers

In recent years, a wide range of studies have pointed out the importance of nutraceuticals as reservoirs of therapeutic compounds for several diseases, including cancer. This study is centered on the role of some nutraceuticals as anticancer agents and on their efficiency in the oncological gynecological field. Gynecological cancers include cervical, ovarian, and breast neoplasia and these are the major causes of morbidity and mortality in the female population. Cervical neoplasia affects sexually active women aged between 30 and 40 years and is considered the second leading cause of death for women worldwide. Epidemiological studies have shown a strong association of this cancer with human papilloma virus (HPV) infection, independent of any others risk factors. Ovarian cancer represents about 4% of all women’s cancers and breast neoplasia registers 52.8 new cases per 100,000 women annually. Since ancient times, herbal therapies have shown a wide range of beneficial effects and a high potential for safeguarding human health. Azadirachta indica (Neem) is a medicinal plant of Indian origin, a tree with more of 140 isolated compounds and at least 35 biologically active principles that have shown an important influence as tumor suppressors by interfering with the carcinogenesis process. Used for centuries in Asia as a natural remedy for cancer, neem compounds present in bark, leaves, flowers, and seed oil have been shown to possess properties such as chemopreventive capacity, apoptotic activities, immunomodulatory effects, and induction of p53-independent apoptosis. The current study is a systematic literature review based on the anticarcinogenic potential of neem compounds in gynecological cancers.

Cancers Due to Excess Weight, Low Physical Activity, and Unhealthy Diet

BACKGROUND

Excess weight, low physical activity, low intakes of dietary fiber, fruits, and vegetables, and high meat and salt intake increase cancer risk.

METHODS

Numbers and proportions (population-attributable fractions, PAF) of incident cancer cases in Germany in 2018 attributable to these factors were estimated by sex and age groups for ages 35 to 84 years using population projections, national cancer incidence and exposure data, and published risk estimates.

RESULTS

Estimated numbers (percentages) of attributable cancers were 30 567 (7%) for excess weight, 27 081 (6%) for low physical activity, 14 474 (3%) for low dietary fiber intake, 9447 (2%) for low fruit and vegetable consumption, 9454 (2%) and 1687 (0.4%) for processed meat and high red meat consumption, respectively, and 1204 (0.3%) for high salt intake. Excess weight substantially contributed to endometrial, renal, and liver cancer (PAF = 24 to 35%). Low physical activity contributed to endometrial, renal, and lung cancer (PAF = 15 to 19%), and dietary factors mainly contributed to colorectal, breast, and lung cancer (PAF = 9 to 16%).

CONCLUSION

A considerable proportion of cancer cases are attributable to excess weight, physical inactivity, and unhealthy dietary habits. Major prevention efforts are needed to reduce the cancer incidence attributable to these avoidable factors.

Breast cancer screening (BCS) chart: a basic and preliminary model for making screening mammography more productive and efficient

BACKGROUND

The breast cancer screening (BCS) chart is suggested as a basic and preliminary tool to improve efficiency of screening mammography.

METHODS

We conducted this case-control study in 2016 and enrolled 1422 women aged 30-75 years, including 506 women with breast cancer (cases) and 916 women without breast cancer (controls). We developed the BCS chart using a multiple logistic regression analysis. We combined the risks of breast cancer to predict the individual risk of breast cancer. Then, we stratified and colored the predicted risk probabilities as follows: <05% (green), 05-09% (yellow), 10-14% (orange), 15-19% (red), 20-24% (brown) and ≥25% (black).

RESULTS

The BCS chart provides the risk probability of breast cancer, based on age, body mass index, late menopause, having a benign breast disease and a positive family history of breast cancer among the first-degree or the second/third-degree relatives. According to this chart, an individual can be classified in a category of low risk (green), medium risk (yellow and orange), high risk (red and brown) and very high risk (black) for breast cancer.

CONCLUSIONS

This chart is a flexible and easy to use tool that can detect high-risk subjects and make the screening program more efficient and productive.

Prepregnancy obesity: a risk factor for future development of ovarian and breast cancer

The aim of this study was to investigate the association between a history of prepregnancy obesity and a woman's future long-term risk for the development of female malignancies. A population-based study compared the incidence of long-term female malignancies in a cohort of consecutive women with and without a diagnosis of prepregnancy obesity. Deliveries occurred between the years 1988 and 2013, with a mean follow-up duration of 11.6 years. Women with known malignancies before the index pregnancy and known genetic predisposition for malignancy were excluded from the study. Female malignancies were divided according to specific type (ovary, uterine, breast, and uterine cervix). A Kaplan-Meier survival curve was used to estimate the cumulative incidence of malignancies. A Cox proportional hazards model was used to estimate the adjusted hazard ratios for female malignancy. During the study period, 106 251 deliveries fulfilled the inclusion criteria; 2.2% (n=2360) occurred in patients with a history of prepregnancy obesity. During the follow-up period, patients with prepregnancy obesity had a significantly increased risk for hospitalization because of female malignancies as a group and specifically ovarian and breast cancer. Using a Kaplan-Meier survival curve, patients with a previous diagnosis of prepregnancy obesity had a significantly higher cumulative incidence of female malignancies. Using a Cox proportional hazards model, adjusted for confounders such as gestational diabetes mellitus and maternal age, prepregnancy obesity remained independently associated with long-term risk for female malignancies (adjusted hazard ratio: 1.4; 95% confidence interval: 1.1-1.9; P=0.045). Prepregnancy obesity is an independent risk factor for long-term female malignancies such as ovarian and breast cancer.

Obesity and gynaecological and obstetric conditions: umbrella review of the literature

Objective To study the strength and validity of associations between adiposity and risk of any type of obstetric or gynaecological conditions.Design An umbrella review of meta-analyses.Data sources PubMed, Cochrane database of systematic reviews, manual screening of references for systematic reviews or meta-analyses of observational and interventional studies evaluating the association between adiposity and risk of any obstetrical or gynaecological outcome.Main outcomes Meta-analyses of cohort studies on associations between indices of adiposity and obstetric and gynaecological outcomes.Data synthesis Evidence from observational studies was graded into strong, highly suggestive, suggestive, or weak based on the significance of the random effects summary estimate and the largest study in the included meta-analysis, the number of cases, heterogeneity between studies, 95% prediction intervals, small study effects, excess significance bias, and sensitivity analysis with credibility ceilings. Interventional meta-analyses were assessed separately.Results 156 meta-analyses of observational studies were included, investigating associations between adiposity and risk of 84 obstetric or gynaecological outcomes. Of the 144 meta-analyses that included cohort studies, only 11 (8%) had strong evidence for eight outcomes: adiposity was associated with a higher risk of endometrial cancer, ovarian cancer, antenatal depression, total and emergency caesarean section, pre-eclampsia, fetal macrosomia, and low Apgar score. The summary effect estimates ranged from 1.21 (95% confidence interval 1.13 to 1.29) for an association between a 0.1 unit increase in waist to hip ratio and risk endometrial cancer up to 4.14 (3.61 to 4.75) for risk of pre-eclampsia for BMI >35 compared with <25. Only three out of these eight outcomes were also assessed in meta-analyses of trials evaluating weight loss interventions. These interventions significantly reduced the risk of caesarean section and pre-eclampsia, whereas there was no evidence of association with fetal macrosomia.Conclusions Although the associations between adiposity and obstetric and gynaecological outcomes have been extensively studied, only a minority were considered strong and without hints of bias.

Novel biomolecule lycopene-reduced graphene oxide-silver nanoparticle enhances apoptotic potential of trichostatin A in human ovarian cancer cells (SKOV3)

Background

Recently, there has been much interest in the field of nanomedicine to improve prevention, diagnosis, and treatment. Combination therapy seems to be most effective when two different molecules that work by different mechanisms are combined at low dose, thereby decreasing the possibility of drug resistance and occurrence of unbearable side effects. Based on this consideration, the study was designed to investigate the combination effect of reduced graphene oxide-silver nanoparticles (rGO-AgNPs) and trichostatin A (TSA) in human ovarian cancer cells (SKOV3).

Methods

The rGO-AgNPs were synthesized using a biomolecule called lycopene, and the resultant product was characterized by various analytical techniques. The combination effect of rGO-Ag and TSA was investigated in SKOV3 cells using various cellular assays such as cell viability, cytotoxicity, and immunofluorescence analysis.

Results

AgNPs were uniformly distributed on the surface of graphene sheet with an average size between 10 and 50 nm. rGO-Ag and TSA were found to inhibit cell viability in a dose-dependent manner. The combination of rGO-Ag and TSA at low concentration showed a significant effect on cell viability, and increased cytotoxicity by increasing the level of malondialdehyde and decreasing the level of glutathione, and also causing mitochondrial dysfunction. Furthermore, the combination of rGO-Ag and TSA had a more pronounced effect on DNA fragmentation and double-strand breaks, and eventually induced apoptosis.

Conclusion

This study is the first to report that the combination of rGO-Ag and TSA can cause potential cytotoxicity and also induce significantly greater cell death compared to either rGO-Ag alone or TSA alone in SKOV3 cells by various mechanisms including reactive oxygen species generation, mitochondrial dysfunction, and DNA damage. Therefore, this combination chemotherapy could be possibly used in advanced cancers that are not suitable for radiation therapy or surgical treatment and facilitate overcoming tumor resistance and disease progression.

Impact of body mass index on ovarian cancer survival varies by stage

BACKGROUND

Research on the effect of body mass index (BMI) on ovarian cancer survival is inconsistent, but previous studies did not consider the possible impact of ascites, bowel obstruction, or cachexia, which commonly occur in late-stage disease.

METHODS

We evaluated the association of BMI, before and around the time of diagnosis, with overall and disease-specific survival in a cohort study of primary invasive epithelial ovarian cancers diagnosed from 2000 to 2013 in Kaiser Permanente Northern California (KPNC) (n=1184). Deaths were identified through December 2014, with a median follow-up of 37 months. Proportional hazards regression was used to estimate overall and ovarian cancer-specific mortality, accounting for prognostic variables including age at diagnosis, race, stage, grade, histology, comorbidities, treatment, post-treatment CA125 levels, ascites, and bowel obstruction.

RESULTS

There was no evidence of an association between BMI and overall or ovarian cancer-specific survival. However, we found strong effect modification by stage (Pinteraction<0.01). Compared with normal prediagnosis BMI (18.5-24.9 kg m-2), for women who were obese before diagnosis (BMI⩾35 kg m-2) ovarian cancer-specific survival was lower among those diagnosed at stages I/II (hazard ratio (HR): 3.40; 95% confidence interval (CI): 1.16-9.99), but increased among those diagnosed with stage IV disease (HR: 0.58; 95% CI: 0.35-0.96). Associations were attenuated after excluding those diagnosed with cachexia (n=82) and further adjustment for ascites and bowel obstruction, with no evidence of effect modification by these factors.

CONCLUSIONS

Associations of obesity with ovarian cancer survival may differ by stage, with decreased survival among those with localised disease and increased survival among those with late-stage disease. Stage-specific effects of obesity on survival suggest a tailored approach to improve prognosis may be appropriate.

Proportion of cancer in a Middle eastern country attributable to established risk factors

Background

Providing an estimate of the percentage of cancer in Lebanon by 2018 that is due to the exposure to risk factors in 2008. Factors include: smoking, body mass index (BMI), physical inactivity, dietary factors, alcohol consumption, infections, and air pollution in adults.

Method

Population Attributable Fraction (PAF) was calculated using the proportion of the population exposed and relative risks for each risk factor from meta-analyses. The PAF estimates the proportion of cases in which exposure may have played a causal role.

Results

Smoking caused most cancer cases, and it will further add a total of 1800 new cases by 2018. Among many other cancers, lung cancer had the largest proportion attributable of around 75%. BMI is expected to increase colorectal, liver and gastric cardia carcinoma specifically in males. High physical activity has a an average of 15% protection rate on cancer on colorectal cancer. Minimal adherence to Mediterranean diet will affect gastric cancer incidence by 7%. Cases of oropharyngeal and esophageal cancer will be the result of alcohol consumption mainly in males. H.Pylori infection is expected to result in half of the gastric cases by 2018. The high exposure to air pollution is expected to contribute by 13% to lung cancer cases in 2018.

Conclusion

The highest benefits can be achieved by controlling tobacco smoking. Interrelated and small changes in weight, physical activity and healthy diet with limited alcohol consumption can protect against several GI cancers in the long run. These results can be used to determine public health interventions that target important risk factors in the general population.

Adiposity and cancer at major anatomical sites: umbrella review of the literature

Objective To evaluate the strength and validity of the evidence for the association between adiposity and risk of developing or dying from cancer.Design Umbrella review of systematic reviews and meta-analyses.Data sources PubMed, Embase, Cochrane Database of Systematic Reviews, and manual screening of retrieved references.Eligibility criteria Systematic reviews or meta-analyses of observational studies that evaluated the association between indices of adiposity and risk of developing or dying from cancer.Data synthesis Primary analysis focused on cohort studies exploring associations for continuous measures of adiposity. The evidence was graded into strong, highly suggestive, suggestive, or weak after applying criteria that included the statistical significance of the random effects summary estimate and of the largest study in a meta-analysis, the number of cancer cases, heterogeneity between studies, 95% prediction intervals, small study effects, excess significance bias, and sensitivity analysis with credibility ceilings.Results 204 meta-analyses investigated associations between seven indices of adiposity and developing or dying from 36 primary cancers and their subtypes. Of the 95 meta-analyses that included cohort studies and used a continuous scale to measure adiposity, only 12 (13%) associations for nine cancers were supported by strong evidence. An increase in body mass index was associated with a higher risk of developing oesophageal adenocarcinoma; colon and rectal cancer in men; biliary tract system and pancreatic cancer; endometrial cancer in premenopausal women; kidney cancer; and multiple myeloma. Weight gain and waist to hip circumference ratio were associated with higher risks of postmenopausal breast cancer in women who have never used hormone replacement therapy and endometrial cancer, respectively. The increase in the risk of developing cancer for every 5 kg/m2 increase in body mass index ranged from 9% (relative risk 1.09, 95% confidence interval 1.06 to 1.13) for rectal cancer among men to 56% (1.56, 1.34 to 1.81) for biliary tract system cancer. The risk of postmenopausal breast cancer among women who have never used HRT increased by 11% for each 5 kg of weight gain in adulthood (1.11, 1.09 to 1.13), and the risk of endometrial cancer increased by 21% for each 0.1 increase in waist to hip ratio (1.21, 1.13 to 1.29). Five additional associations were supported by strong evidence when categorical measures of adiposity were included: weight gain with colorectal cancer; body mass index with gallbladder, gastric cardia, and ovarian cancer; and multiple myeloma mortality.Conclusions Although the association of adiposity with cancer risk has been extensively studied, associations for only 11 cancers (oesophageal adenocarcinoma, multiple myeloma, and cancers of the gastric cardia, colon, rectum, biliary tract system, pancreas, breast, endometrium, ovary, and kidney) were supported by strong evidence. Other associations could be genuine, but substantial uncertainty remains. Obesity is becoming one of the biggest problems in public health; evidence on the strength of the associated risks may allow finer selection of those at higher risk of cancer, who could be targeted for personalised prevention strategies.

The association between polycystic ovary syndrome and breast cancer: a meta-analysis

Objective

The results of epidemiological studies investigated the association between polycystic ovary syndrome (PCOS) and the breast cancer are inconsistent. This meta-analysis was conducted to estimate the association between PCOS and the breast cancer risk. We searched PubMed, Web of Science, and Scopus for observational studies until June 2015. Data were independently extracted and analyzed using 95% odds ratio, and confidence intervals (CIs) based on the random-effects models.

Methods

We identified 970 references and conducted eight studies with 45,470 participants and 243,064 person- year.

Results

The association between PCOS and the breast cancer risk in case-control studies 0.87 (95% CI, 0.44 to 1.31) and that of cohort studies was estimated 1.18 (95% CI, 0.93 to 1.43).

Conclusion

This meta-analysis demonstrated that PCOS no does increase the risk of breast cancer. Further prospective cohort studies are needed to provide convincing evidence in order to PCOS can increase or not effect on the risk of the breast cancer.

SKP2/P27Kip1 pathway is associated with Advanced Ovarian Cancer in Saudi Patients

BACKGROUND

Ovarian cancer is the most common gynecological malignancy and constitutes the fifth leading cause of female cancer death. Some biological parameters have prognostic roles in patients with advanced ovarian cancer and their expression may contribute to tumor progression. The aim of this study was to investigate the potential prognostic value of SKP2, genes P27Kip1, K-ras, c-Myc, COX2 and HER2 genes expression in ovarian cancer.

MATERIALS AND METHODS

This study was performed on two hundred formalin fixed paraffin embedded ovarian cancer and normal adjacent tissues (NAT). Gene expression levels were assessed using real time PCR and Western blotting.

RESULTS

Elevated expression levels of SKP2, K-ras, c-Myc, HER2 and COX2 genes were observed in 61.5% (123/200), 92.5% (185/200), 74% (148/200), 96 % (192/200), 90% (180/200) and 78.5% (157/200) of cancer tissues, respectively. High expression of SKP2 and down-regulation of P27 was associated with advanced stages of cancer.

CONCLUSIONS

The association between high expression of c-Myc and SKP2 with low expression of P27 suggested that the Skp2-P27 pathway may play an important role in ovarian carcinogenesis. Reduced expression of P27 is associated with advanced stage of cancer and can be used as a biological marker in clinical routine assessment and management of women with advanced ovarian cancer.

Obesity, weight gain, and ovarian cancer risk in African American women

Although there is growing evidence that higher adiposity increases ovarian cancer risk, little is known about its impact in African American (AA) women, the racial/ethnic group with the highest prevalence of obesity. We evaluated the impact of body mass index (BMI) 1 year before diagnosis and weight gain since age 18 years on ovarian cancer risk in a population-based case-control study in AA women in 11 geographical areas in the US. Cases (n = 492) and age and site matched controls (n = 696) were identified through rapid case ascertainment and random-digit-dialing, respectively. Information was collected on demographic and lifestyle factors, including self-reported height, weight at age 18 and weight 1 year before diagnosis/interview. Multivariable logistic regression was used to compute odds ratios (OR) and 95% confidence intervals (CI), adjusting for potential covariates. Obese women had elevated ovarian cancer risk, particularly for BMI ≥ 40 kg/m(2) compared to BMI <25 (OR = 1.72, 95% CI: 1.12-2.66; p for trend: 0.03). There was also a strong association with weight gain since age 18 (OR: 1.52; 95% CI: 1.07-2.16; p for trend: 0.02) comparing the highest to lowest quartile. In stratified analyses by menopausal status, the association with BMI and weight gain was limited to postmenopausal women, with a 15% (95% CI: 1.05-1.23) increase in risk per 5 kg/m(2) of BMI and 6% (95% CI: 1.01-1.10) increase in risk per 5 kg of weight gain. Excluding hormone therapy users essentially did not change results. Obesity and excessive adult weight gain may increase ovarian cancer risk in post-menopausal AA women.

The incidence and mortality of ovarian cancer and their relationship with the Human Development Index in Asia

Background

The incidence and mortality estimates of ovarian cancer based on human development are essential for planning by policy makers. This study is aimed at investigating the standardised incidence rates (SIR) and standardised mortality rates (SMR) of ovarian cancer and their relationship with the Human Development Index (HDI) in Asian countries.

Methods

This study was an ecologic study in Asia for assessment of the correlation between SIR, age standardised rates (ASR), and HDI and their details, including life expectancy at birth, mean years of schooling, and gross national income (GNI) per capita. We used the correlation bivariate method for assessment of the correlation between ASR and HDI, and its details. Statistical significance was assumed if P < 0.05. All reported P-values were two-sided. Statistical analyses were performed using SPSS (Version 15.0, SPSS Inc.).

Results

The highest SIR of ovarian cancer was observed in Singapore, Kazakhstan, and Brunei respectively. Indonesia, Brunei, and Afghanistan had the highest SMR. There was a positive correlation between the HDI and SIR (r = 0.143, p = 0.006). Correlation between SMR of ovarian cancer and HDI was not significant (r = 0.005, p = 052.0).

Conclusion

According to the findings of this study, between the HDI and SIR, there was a positive correlation, but there was no correlation between the SMR and HDI.

The association between body mass index and preeclampsia: a meta-analysis

BACKGROUND

Several observational studies have reported a positive association between elevated body mass index (BMI) and preeclampsia, but no meta-analysis has been conducted yet. This meta-analysis was conducted to estimate the overall association between overweight or obesity and preeclampsia.

METHODS

Major electronic databases, including PubMed, Web of Science, and Scopus were searched until August 2015. The reference lists of included studies were screened as well. Epidemiological studies addressing the association between BMI and preeclampsia were enrolled. The heterogeneity across studies was explored by Q-test and I(2) statistic. The possibility of publication bias was assessed using Begg's and Egger's tests. The results were reported using odds ratio (OR) estimate with its 95% confidence intervals (CI) using a random-effects model.

RESULTS

We identified a total of 1298 references and included 23 studies with 1 387 599 participants. Preeclampsia was associated with overweight (OR = 1.73; 95% CI: 1.59, 1.87; 21 studies; I(2 )=( )62.3%) and obesity (OR = 3.15; 95% CI: 2.96, 3.35; 22 studies; I(2 )=( )36.0%). There was no evidence of publication bias.

CONCLUSIONS

There is sufficient evidence that excess body mass index is significantly associated with an increased risk of preeclampsia. Therefore, overweight and obesity can be considered as a predictor of preeclampsia.

Substance use disorder and risk of suicidal ideation, suicide attempt and suicide death: a meta-analysis

BACKGROUND

This meta-analysis addressed the association between substance use disorder (SUD) and suicide outcomes based on current evidence.

METHODS

We searched PubMed, Web of Science and Scopus until May 2015. We also searched the reference lists of included studies and Psycinfo website. We included observational (cohort, case-control, cross-sectional) studies addressing the association between SUD and suicide. Our outcomes of interest were suicide ideation, suicide attempt and suicide death. For each outcome, we calculated the odds ratio (OR) or risk ratio (RR) with 95% confidence intervals (CI) based on the random-effects model.

RESULTS

We identified a total of 12 413 references and included 43 studies with 870 967 participants. There was a significant association between SUD and suicidal ideation: OR 2.04 (95% CI: 1.59, 2.50; I² = 88.8%, 16 studies); suicide attempt OR 2.49 (95% CI: 2.00, 2.98; I² = 94.3%, 24 studies) and suicide death OR 1.49 (95% CI: 0.97, 2.00; I² = 82.7%, 7 studies).

CONCLUSIONS

Based on current evidence, there is a strong association between SUD and suicide outcomes. However, evidence based on long-term prospective cohort studies is limited and needs further investigation. Moreover, further evidence is required to assess and compare the association between suicide outcomes and different types of illicit drugs, dose-response relationship and the way they are used.

The association between overweight, obesity and ovarian cancer: a meta-analysis

OBJECTIVE

Epidemiological studies have reported an inconsistent association between obesity and ovarian cancer. To update the current knowledge of and further qualify the association between overweight, obesity and ovarian cancer risk, we conducted a meta-analysis of published observational studies.

METHODS

Using the PubMed, MEDLINE and EMBASE databases, we performed a literature search of all of the case-control and cohort studies published as original articles in English before March 2015. We included 26 observational studies, of which 13 were case-control studies (7782 cases and 21 854 controls) and 13 were cohort studies (5181 cases). Fixed- and random-effects models were used to compute summary estimates and the corresponding 95% confidence intervals. Subgroup analyses were also performed.

RESULTS

The pooled relative risk for overweight and obesity compared with normal weight (body mass index = 18.5-24.9 kg/m(2)) was 1.07 (95% confidence interval: 1.02-1.12) and 1.28 (95% confidence interval: 1.16-1.41), respectively. In subgroup analyses, we found that overweight/obesity increased the risk of ovarian cancer in most groups, except for the postmenopausal group (overweight: pooled relative risk = 0.97, 95% confidence interval: 0.76-1.24; obesity: pooled relative risk = 0.93, 95% confidence interval: 0.61-1.42). There was no evidence of publication bias.

CONCLUSIONS

Increased body weight was associated with an increased risk of ovarian cancer; in particular, severe obesity demonstrated a stronger risk effect. No statistically significant association was observed in the postmenopausal period, but was in the premenopausal period.

Reproductive factors, adiposity, breastfeeding and their associations with ovarian cancer in an Asian cohort

PURPOSE

The aim of this study was to assess associations of breastfeeding, adiposity and reproductive risk factors with ovarian cancer risk in a Singaporean population. In addition to the main analysis, interaction effects of parity on other risk factors were examined.

METHODS

A retrospective cohort consisting of 28,201 women with 107 incident ovarian cancers in up to 17 years of follow-up from the Singapore Breast Cancer Screening Project (1994-1997) was studied. Hazard ratios (HRs) for risk factors were estimated using Cox proportional hazards models.

RESULTS

Body mass index and breastfeeding were found to have no statistical significant association with ovarian cancer risk. Gravidity was inversely associated with ovarian cancer risk [each pregnancy, adjusted HR 0.89, 95% confidence interval (CI) 0.81, 0.97], while results for parity were very similar (per delivery, HR 0.89, 95% CI 0.81, 0.98). Each additional year of ovulatory period was found to increase ovarian cancer risk by 2% (HR 1.02, 95% CI 1.00, 1.04). Each year increase in total duration of oral contraceptive use reduced ovarian cancer risk by 6% (HR 0.94, 95% CI 0.85, 1.02).

CONCLUSIONS

Parity, gravidity and shorter ovulatory period were associated with lower ovarian cancer risk. Breastfeeding and body mass index were not associated with ovarian cancer risk, while increased duration of oral contraceptive use resulted in borderline risk reduction. No significant evidence was found to suggest that parity had an interaction effect on any risk factor.