Prevention of cancers of the breast, endometrium and ovary

Fraction of cancers attributable to and prevented by reproductive factors and exogenous hormones use in Italy

OBJECTIVE

Endogenous and exogenous hormonal factors have been associated with female breast, genital, and colorectal cancer risk. The aim of the present study is to conduct an evidence-based evaluation of the fraction of cancers attributable to and prevented by exogenous hormonal (i.e., combined oral contraceptives [COC] and combined estrogen-progestogen menopausal therapy [CEPMT]) and reproductive factors (i.e., parity and breastfeeding) in Italy.

STUDY DESIGN

We calculated the population attributable and prevented fractions combining relative risks and prevalence of exposure in Italian women. Italian cancer incidence and mortality data were extracted from national sources and used to estimate the number of cancer cases and deaths attributable to reproductive factors and exogenous hormones in Italy in 2020. For long-term effects, a 20-year latency period was considered.

RESULTS

COC were responsible for 4.4 % of breast and 10.9 % of cervical cancers in women aged 15-44, but also avoided 6.4 % of endometrial, 5.6 % of ovarian, and 2.9 % of colorectal cancers in women of all ages. Overall, COC use prevented 1174 cancer diagnoses and 577 cancer deaths. CEPMT caused 0.4 % of breast cancers at age 45-69. Low parity accounted for 8.1 %, 11.8 % and 15.5 % of breast, endometrial and ovarian cancers, respectively (6267 cases, 1796 deaths). Breastfeeding avoided 6.4 % of breast cancers (3775 cases, 897 deaths).

CONCLUSIONS

Our analysis quantified the complex effects of hormonal and reproductive factors on cancer burden in Italian women.

Comparison of the effectiveness of the levonorgestrel-intrauterine device and oral progestogens on regression of endometrial hyperplasia without atypia

Endometrial hyperplasia is caused by an excess of estrogen unopposed by progesterone. Oral progestogens are traditionally used for endometrial hyperplasia without atypia. However oral progestogen is not always successful at causing regression of endometrial hyperplasia. In addition, cyclic progestogens are less effective in delivering progestogen to the endometrium. Therefore, the levonorgestrel-intrauterine device (LNG-IUD), as an alternative option of delivery progestogen has been introduced in clinical practice. The effectiveness of LNG-IUD in causing regression of endometrial hyperplasia in the short-term had moderate-quality evidence, but the long-term (13 months to two years) effectiveness had low-quality evidence. In this study with relatively large sample size, we compared the effectiveness in the regression of endometrial hyperplasia without atypia for short-term and long-term between the treatment with LNG-IUD and oral progestogens or no treatment. Data on histology or ultrasound from 466 cases who received either LNG-IUD or oral progestogens or were untreated were collected. The primary treatment with LNG-IUD showed a 93% regression rate of endometrial hyperplasia, which was significantly higher than oral progestogens showing a 66% regression rate. The odds ratio of regression of endometrial hyperplasia in cases with LNG-IUD treatment was 7.128 (95%CI: 2.94, 16.76, p < 0.0001), compared to the cases with oral progestogen treatment. The regression rate in untreated cases was 16%. In addition, cases without regression by oral progestogens who then received the alternative treatment option by LNG-IUD also showed a 93% regression rate. While continuously receiving oral progestogens showed a 55% regression rate of endometrial hyperplasia, which was significantly lower than LNG-IUD treatment as an alternative option. Our data reports a significant response on regression of endometrial hyperplasia after LNG-IUD treatment in comparison with oral progestogen treatment.

Understanding How Pregnancy Protects Against Ovarian and Endometrial Cancer Development: Fetal Antigens May Be Involved

It is well known that many factors, including infertility, obesity, type 2 diabetes, and family history of cancer, increase the risk of developing endometrial and ovarian cancer. However, multiparous women are known to have a lower risk of developing either ovarian or endometrial cancer than nonparous women. The lack of ovulation and shifting of sex hormonal balance, with decreased estrogen levels and increased progesterone levels during pregnancy, has traditionally been thought to be the major contributor to this decreased risk. However, in reality, the mechanisms underlying this phenomenon are relatively unknown. Increasing evidence suggests that endocrine factors are unlikely to completely explain the protective effect of pregnancies, and that multiple other nonendocrine mechanisms including fetal antigens and the newly proposed dormant cells hypothesis may also be involved. In this review, we summarize recent evidence and describe the potential underlying mechanisms that may explain how pregnancy protects against the development of ovarian and endometrial cancers in women's later life.

Obesity, cancer risk, and time-restricted eating

Obesity and the associated metabolic syndrome is considered a pandemic whose prevalence is steadily increasing in many countries worldwide. It is a complex, dynamic, and multifactorial disorder that presages the development of several metabolic, cardiovascular, and neurodegenerative diseases, and increases the risk of cancer. In patients with newly diagnosed cancer, obesity worsens prognosis, increasing the risk of recurrence and decreasing survival. The multiple negative effects of obesity on cancer outcomes are substantial, and of great clinical importance. Strategies for weight control have potential utility for both prevention efforts and enhancing cancer outcomes. Presently, time-restricted eating (TRE) is a popular dietary intervention that involves limiting the consumption of calories to a specific window of time without any proscribed caloric restriction or alteration in dietary composition. As such, TRE is a sustainable long-term behavioral modification, when compared to other dietary interventions, and has shown many health benefits in animals and humans. The preliminary data regarding the effects of time-restricted feeding on cancer development and growth in animal models are promising but studies in humans are lacking. Interestingly, several short-term randomized clinical trials of TRE have shown favorable effects to reduce cancer risk factors; however, long-term trials of TRE have yet to investigate reductions in cancer incidence or outcomes in the general population. Few studies have been conducted in cancer populations, but a number are underway to examine the effect of TRE on cancer biology and recurrence. Given the simplicity, feasibility, and favorable metabolic improvements elicited by TRE in obese men and women, TRE may be useful in obese cancer patients and cancer survivors; however, the clinical implementation of TRE in the cancer setting will require greater in-depth investigation.

Predicting Cohort-Specific Cervical Cancer Incidence From Population-Based Surveys of Human Papilloma Virus Prevalence: A Worldwide Study

Predictions of cervical cancer burden and the impact of measures taken to control this cancer are usually data-demanding and based on complex assumptions. We propose a predictive method (called PANDORA) based on human papillomavirus (HPV) prevalence, measured 1993-2008, and cervical cancer incidence (CCI), measured 1993-2012, in the same birth cohorts from different worldwide locations, informed by data on age at detection of high-risk HPV and sexual debut. The model can predict CCI among high-risk HPV-positive women and predict CCI up to 14 years following high-risk HPV detection. We found CCI to increase during the 14 years following high-risk HPV detection in unscreened women aged <35 years but to remain mainly constant among women ≥35 years. Age at sexual debut was a significant modifier of CCI. Using our model, we accurately reproduced CCI among high-risk HPV-positive women as observed in cohort studies and in the general population of multiple countries. We also predicted the annual number of cervical cancer cases and CCI in locations with HPV prevalence data but no cancer registry. These findings could inform cervical cancer control programs in settings without cancer registries, as they can be used to predict future cervical cancer burden from population-based surveys of HPV prevalence.

Identifying environmental exposure profiles associated with timing of menarche: A two-step machine learning approach to examine multiple environmental exposures

BACKGROUND

Variation in the timing of menarche has been linked with adverse health outcomes in later life. There is evidence that exposure to hormonally active agents (or endocrine disrupting chemicals; EDCs) during childhood may play a role in accelerating or delaying menarche. The goal of this study was to generate hypotheses on the relationship between exposure to multiple EDCs and timing of menarche by applying a two-stage machine learning approach.

METHODS

We used data from the National Health and Nutrition Examination Survey (NHANES) for years 2005-2008. Data were analyzed for 229 female participants 12-16 years of age who had blood and urine biomarker measures of 41 environmental exposures, all with >70% above limit of detection, in seven classes of chemicals. We modeled risk for earlier menarche (<12 years of age vs older) with exposure biomarkers. We applied a two-stage approach consisting of a random forest (RF) to identify important exposure combinations associated with timing of menarche followed by multivariable modified Poisson regression to quantify associations between exposure profiles ("combinations") and timing of menarche.

RESULTS

RF identified urinary concentrations of monoethylhexyl phthalate (MEHP) as the most important feature in partitioning girls into homogenous subgroups followed by bisphenol A (BPA) and 2,4-dichlorophenol (2,4-DCP). In this first stage, we identified 11 distinct exposure biomarker profiles, containing five different classes of EDCs associated with earlier menarche. MEHP appeared in all 11 exposure biomarker profiles and phenols appeared in five. Using these profiles in the second-stage of analysis, we found a relationship between lower MEHP and earlier menarche (MEHP ≤ 2.36 ng/mL vs >2.36 ng/mL: adjusted PR = 1.36, 95% CI: 1.02, 1.80). Combinations of lower MEHP with benzophenone-3, 2,4-DCP, and BPA had similar associations with earlier menarche, though slightly weaker in those smaller subgroups. For girls not having lower MEHP, exposure profiles included other biomarkers (BPA, enterodiol, monobenzyl phthalate, triclosan, and 1-hydroxypyrene); these showed largely null associations in the second-stage analysis. Adjustment for covariates did not materially change the estimates or CIs of these models. We observed weak or null effect estimates for some exposure biomarker profiles and relevant profiles consisted of no more than two EDCs, possibly due to small sample sizes in subgroups.

CONCLUSION

A two-stage approach incorporating machine learning was able to identify interpretable combinations of biomarkers in relation to timing of menarche; these should be further explored in prospective studies. Machine learning methods can serve as a valuable tool to identify patterns within data and generate hypotheses that can be investigated within future, targeted analyses.

Complications of Pregnancy and the Risk of Developing Endometrial or Ovarian Cancer: A Case-Control Study

BACKGROUND

The association of complications of pregnancy and the risk of developing gynecological cancer is controversial with the limited study. In this study, we investigated the association of preeclampsia, or gestational diabetes mellitus (GDM), or large for gestational age (LGA), or intrauterine growth restriction (IUGR) and the risk of endometrial or ovarian cancer.

METHODS

In this case-control study, 189 women with endometrial cancer and 119 women with ovarian cancer were included. 342 women without gynecological cancers were randomly selected as a control group. Data on the history of pregnancy and age at diagnosis of gynecological cancer as well as the use of intrauterine devices (IUDs) were collected.

RESULTS

Women with a history of preeclampsia or IUGR did not have an increased risk of developing endometrial or ovarian cancer. While women with a history of GDM or with the delivery of LGA infant increased the risk of developing endometrial cancer but not ovarian cancer. The odds of women with a history of GDM or with the delivery of LGA infant developing endometrial cancer was 2.691 (95% CI: 1.548, 4.3635, p=0.0003), or 6.383 (95% CI: 2.812, 13.68, p<0.0001) respectively, compared to the controls. The odds ratio of women who did not use IUDs developing ovarian cancer was 1.606 (95% CI: 1.057, 2.434), compared to the controls. There was no association of age at first birth and developing endometrial or ovarian cancer.

CONCLUSION

Our observational data suggested that GDM and delivery of an LGA infant are associated with an increased risk of endometrial cancer.

Breast cancer among Asian Indian and Pakistani Americans: A surveillance, epidemiology and end results-based study

Breast cancer incidence is increasing among Asian Indian and Pakistani women living in the United States. We examined the characteristics of breast cancer in Asian Indian and Pakistani American (AIPA) and non-Hispanic white (NHW) women using data from the surveillance, epidemiology and end results (SEER) program. Breast cancer incidence rates were estimated via segmented Poisson regression using data between 1990 and 2014 from SEER 9 registries, including New Jersey and California. Disease characteristics, treatment and survival information between 2000 and 2016 for 4900 AIPA and 482 250 NHW cases diagnosed after age 18 were obtained from SEER 18 registries and compared using descriptive analyses and multivariable competing risk proportional hazards regression. Breast cancer incidence was lower in AIPA than NHW women, increased with age and the rate of increase declined after age of 46 years. AIPA women were diagnosed at significantly younger age (mean (SD) = 54.5 (13.3) years) than NHW women (mean (SD) = 62 (14) years, P < .0001) and were more likely than NHW cases (P < .0001) to have regional or distant stage, higher grade, estrogen receptor-negative, progesterone receptor-negative, triple-negative or human epidermal growth factor receptor 2-enriched tumors, subcutaneous or total mastectomy, and lower cumulative incidence of death due to breast cancer (hazard ratio = 0.79, 95% CI: 0.72-0.86, P < .0001). AIPA had shorter median follow-up (52 months) than NHW cases (77 months). Breast cancer in AIPA women has unique characteristics that need to be further studied along with a comprehensive evaluation of their follow-up patterns.

Endometrial cancer: mapping the global landscape of research

Background

From a global viewpoint, endometrial cancer belongs to the most common female cancers. Despite the heavy burden of diseases and numerous unanswered questions, no detailed pictures of the global structure of endometrial cancer research are available so far. Therefore, this malignancy was reviewed using the New Quality and Quantity Indices in Science (NewQIS) protocol.

Methods

Using NewQIS, we identified endometrial carcinoma related research published in the Web of Science from 1900–2015 (P1) and from 2016–2020 (P2). Item analysis was performed with regard to research activity. Also, semi-qualitative aspects and socio-economic benchmarks were visualized using density equalizing mapping.

Results

In total, 9,141 from 1900–2015 and 4,593 from 2016–2020 endometrial cancer related studies were identified with the USA having the largest numbers of publications, citations, institutions, as well as the highest country-specific h-Index concerning endometrial cancer research in both periods. In contrast to other fields of cancer research, the two East Asian countries Japan and China followed concerning total research activities until 2015. From 2016 until 2020, China was found in short distance to the USA and was ranked second. In the socio-economic analysis, European countries were in prominent positions. Greece published 579.83 endometrial carcinoma-related articles per billion US-$ GDP, Finland (527.29), Sweden (494.65), Israel (493.75), and Norway (367.85) followed in the ranking. Density equalizing mapping visualized that large parts of Africa, Asia and South America with a high burden of disease played almost no visible role in the endometrial cancer research activities.

Conclusions

Endometrial cancer research activity is continuously increasing from a global viewpoint. However, the majority of original articles is published by authors based in high-income countries. Together with the finding that the research field of public health does only play a minimal role, our study points to the necessity that global health aspects should be introduced to endometrial cancer research.

Age at Menopause and Risk of Developing Endometrial Cancer: A Meta-Analysis

Object

The association of age at menopause with endometrial cancer remains controversial. Therefore, we quantitatively summarized the evidence from observational studies with a meta-analysis.

Methods

We searched PubMed, Web of Science, Embase, Medline, Chinese National Knowledge Infrastructure (CNKI), and Wan Fang Med online up to March 2019, and all eligible case-control and cohort studies were included in the study. Pooled relative risks (RRs) with 95% confidence intervals (CIs) were calculated using the random-effects model. The dose-response relationship was assessed by restricted cubic spline model. The heterogeneity among studies was evaluated by I². Metaregression was used to explore the potential sources of between-study heterogeneity. Egger's test was used to estimate publication bias.

Results

Eighteen articles including 957242 subjects with 4781 cases were included in the meta-analysis. The pooled RR (95%CI) of endometrial cancer for the highest versus the lowest age at menopause was 1.89 (95%CI: 1.58-2.26). For dose-response analysis, a nonlinear relationship was found between age at menopause and endometrial cancer, and the positive association became statistically significant when age at menopause was greater than 46.5 years old.

Conclusions

This meta-analysis suggested that age at menopause was positively associated with endometrial cancer. For women whose menopausal age over 46.5 years old, the risk of endometrial cancer increased with the age at menopause.

Phagocytosis of Extracellular Vesicles Extruded From the Placenta by Ovarian Cancer Cells Inhibits Growth of the Cancer Cells

OBJECTIVE

Ovarian cancer is a common gynecological cancer, and parity is negatively associated with the incidence of this disease. This negative association is hypothesized to be due in part to shifting the balance of estrogen and progesterone toward more progesterone and reduced ovulation during pregnancy. However, studies suggested that parity is also associated with estrogen-independent gynecological cancers suggesting balance of hormones may not be the only protective factor. Extracellular vesicles (EVs) play an important role in cell-to-cell communication in physiological and pathological conditions. During pregnancy, large amounts of EVs are extruded from the placenta, and they seem to be involved in the remarkable adaptation of a woman's body to normal pregnancy. We hypothesized that EVs extruded from the placenta play a role in this protective effect.

METHODS

Placental EVs were collected from first-trimester placentae, and cancer cell EVs were isolated from ovarian cancer cells. The EVs were exposed to ovarian cancer cells for 48 hours. The proliferation of cancer cells and the cell cycle were measured. In addition, phagocytosis of deported placental EVs by cancer cells was also measured.

RESULTS

The proliferation of cancer cells was significantly reduced by treatment with placental EVs (P = 0.001, analysis of variance), but not EVs from monocytes (P = 0.195), compared with untreated cancer cells. Furthermore, placental EVs also prevented the proliferation of cancer cells induced by cancer cell-derived EVs (P = 0.001). This inhibition of proliferation of ovarian cancer cells was partially due to phagocytosis of placental EVs by cancer cells. Phagocytosis of placental EVs delayed progression through the cell cycle. Calreticulin, a phagocytic "eat me" signal carried by placental EVs significantly inhibited ovarian cancer growth (P = 0.001).

CONCLUSIONS

Our data demonstrated that EVs extruded from the placenta prevented ovarian cancer cell growth by a mechanism that involved delaying progression of the cell cycle after phagocytosis of the EVs.

Breast Cancer in Very Young Patients in a Spanish Cohort: Age as an Independent Bad Prognostic Indicator

Purpose:

Breast cancer (BC) in very young women (BCVY) is more aggressive than in older women. The purpose of this study was to evaluate the relevance of a range of clinico-pathological factors in the prognosis of BCVY patients.

Methods:

We retrospectively analyzed 258 patients diagnosed with BCVY at our hospital from 1998 to 2014; the control group comprised 101 older patients with BC. We correlated clinicopathological factors, treatments, relapse and exitus with age and with previously published miRNA expression data.

Results:

We identified some significant differences in risk factors between BCVY and older patients. The age at menarche, number of pregnancies, and age at first pregnancy were lower in the BCVY group and had a greater probability of recurrence and death in all cases. Lymph node-positive patients in the BCVY group are associated with a worse prognosis (P = .02), an immunohistochemical HER2⁺ subtype, and disease relapse (P = .03). Moreover, there was a shorter time between diagnosis and first relapse in BCVY patients compared with controls, and they were more likely to die from the disease (P = .002). Finally, from our panel of miRNAs deregulated in BC, reduced miR-30c expression was associated with more aggressive BC in very young patients, lower overall survival, and with axillary lymph node metastases.

Conclusions:

Patient age and axillary lymph node status post-surgery are independent and significant predictors of distant disease-free survival, local recurrence-free survival, and overall survival. The HER2⁺ subtype and lower miR-30c expression are related to poor prognosis in lymph node-positive young BC patients.

PES1 promotes the occurrence and development of papillary thyroid cancer by upregulating the ERα/ERβ protein ratio

PES1, a BRCT domain-containing protein, has been shown to play a role in modulating the balance and ratio between ERα and ERβ protein, which is involved in the occurrence and development of breast and ovarian cancer. However, its role in connection with the balance and ratio between ERα and ERβ protein in papillary thyroid cancer (PTC) remains unclear. Here, we found that ERα and ERβ were co-expressed in human PTC tissues and cells. ERα promoted and ERβ inhibited the proliferation, invasion and migration of PTC cells. PES1 modulated the balance between ERα and ERβ by elevating the ERα protein level and simultaneously reducing the ERβ protein level, then upregulating the ERα/ERβ protein ratio and promoting the proliferation, invasion and migration of PTC cells. In PTC tissues, PES1 protein level was positively correlated with the ERα protein level and negatively correlated with the ERβ protein level. The PES1 and ERα protein levels were gradually increased and the ERβ protein level was decreased by degree in the occurrence and development of PTC. Increased PES1 and ERα protein levels and decreased ERβ protein level were correlated with the aggressive behaviors of PTC patients such as large tumor size, extrathyroidal extension (ETE), lymph node metastasis (LNM), high BRAFV600E expression and high TNM stage. It is suggested that PES1 promotes the occurrence and development of PTC by elevating the ERα protein level and reducing the ERβ protein level, and then upregulating the ERα/ERβ protein ratio.

A case-control study of breast cancer risk factors in 7,663 women in Malaysia

BACKGROUND

Breast cancer risk factors have been examined extensively in Western setting and more developed Asian cities/countries. However, there are limited data on developing Asian countries. The purpose of this study was to examine breast cancer risk factors and the change of selected risk factors across birth cohorts in Malaysian women.

METHODS

An unmatched hospital based case-control study was conducted from October 2002 to December 2016 in Selangor, Malaysia. A total of 3,683 cases and 3,980 controls were included in this study. Unconditional logistic regressions, adjusted for potential confounding factors, were conducted. The breast cancer risk factors were compared across four birth cohorts by ethnicity.

RESULTS

Ever breastfed, longer breastfeeding duration, a higher soymilk and soy product intake, and a higher level of physical activity were associated with lower risk of breast cancer. Chinese had the lowest breastfeeding rate, shortest breastfeeding duration, lowest parity and highest age of first full term pregnancy.

CONCLUSIONS

Our study shows that breastfeeding, soy intake and physical activity are modifiable risk factors for breast cancer. With the increasing incidence of breast cancer there is an urgent need to educate the women about lifestyle intervention they can take to reduce their breast cancer risk.

Concomitant high expression of ERα36, GRP78 and GRP94 is associated with aggressive papillary thyroid cancer behavior

PURPOSE

Papillary thyroid cancer (PTC) is more common in women than in men. It has been suggested that estrogen may be involved in its development, as has previously been shown for breast, endometrial and ovarian cancer. The purpose of this study was to assess correlations between the expression of the estrogen receptor alpha36 (ERα36) and the glucose regulated proteins GRP78 and GRP94 (chaperones involved in glycoprotein folding) and various PTC clinicopathological features, as well as to evaluate the potential usefulness of these three potential oncogenic proteins in the prediction of aggressive PTC behavior.

METHODS

ERα36, GRP78 and GRP94 protein expression in 218 primary PTC tissues and PTC-derived BCPAP cells was examined using immunohistochemistry, Western blotting and immunocytochemistry. The proliferative, invasive and migrative capacities of BCPAP cells in which the respective genes were either exogenously over-expressed or silenced were assessed using BrdU incorporation and Transwell assays, respectively.

RESULTS

We found that ERα36, GRP78 and GRP94 protein expression was upregulated in the primary PTC tissues tested. We also found that ERα36, GRP78 and GRP94 expression modulation affected the proliferation, invasion and migration of PTC-derived BCPAP cells. A positive correlation and a positive feedback loop were noted between ERα36, GRP78 and GRP94 protein expression in the primary PTC tissues and in BCPAP cells, respectively. High ERα36 expression in combination with a high GRP78/ GRP94 expression was found to have a stronger correlation with extrathyroid extension (ETE), lymph node metastasis (LNM), distant metastasis (DM) and high TNM stage than high ERα36 expression in combination with either high GRP78 or high GRP94 expression (p = 0.028 for ETE, p = 0.002 for DM and p ≤ 0.001 for LNM and high TNM stage) or high ERα36 expression alone (p < 0.001 for ETE, LNM, DM and high TNM stage).

CONCLUSIONS

From our data we conclude that a concomitant high expression of ERα36, GRP78 and GRP94 is strongly associated with aggressive PTC behavior and may be used as a predictor for ETE, LNM, DM and high TNM stage.

Effect of Genistein and 17-β Estradiol on the Viability and Apoptosis of Human Hepatocellular Carcinoma HepG2 cell line

Background:

One of the most lethal cancers is hepatocellular carcinoma (HCC). Genistein (GE) is a choice compound for treatment of certain types of cancer. Phytoestrogens are plant derivatives that bear a structural similarity to 17-β estradiol (E2) and act in a similar manner. They are a group of lipophillic plant compounds with tumorigenic and antitumorigenic effects. E2 has stimulatory and inhibitory effects on cancer cell lines. This study was designed to investigate the antiproliferative and apoptotic effects of GE and E2 on the HCC HepG2 cell line.

Materials and Methods:

HepG2 cells were cultured and treated with various concentrations of GE and E2 and then 3-[4, 5-dimethyl-2-thiazolyl]-2, 5-diphenyl-2H-tetrazolium bromideand flow cytometry assay were performed to determine cell viability and apoptosis.

Results:

GE and E2 induced apoptosis and inhibited cell growth significantly. Reduction of cell viability by 50% required 20 μM E2 for E2-treatment groups and 20 μMGE for GE-treatment groups. The percentage of the GE-treated apoptotic cells was reduced by about 35%, 42%, and 47% (P < 0.001) and that of E2-treated groups 34%, 39%, and 42% (P < 0.001) after 24, 48, and 72 h, respectively.

Conclusions:

Our experimental work clearly demonstrated that GE and E2 exhibited significant antiproliferative and apoptotic effects on human HCC HepG2 cells.

Concomitant high expression of ERα36, EGFR and HER2 is associated with aggressive behaviors of papillary thyroid carcinomas

ERα, ERβ, PR, ERα36, EGFR and HER2 mRNA and protein expression in papillary thyroid carcinoma (PTC) were examined by real time RT-PCR and immunohistochemical staining. The mRNA and protein expression of ERα and PR were gradually increased and those of ERβ were gradually decreased from normal thyroid tissues to nodular hyperplasias (P < 0.05) and to PTCs (P < 0.05). However, the mRNA and protein expression of ERα36, EGFR and HER2 were only significantly increased in PTCs when compared with those in normal thyroid tissues (P < 0.001) and nodular hyperplasias (P < 0.001). There was some correlation between ERα, ERβ and PR, and between ERα36, EGFR and HER2 protein expression in PTCs. As for ERα, ERβ and PR, there was a significant positive correlation between ERα and PR, and a significant negative correlation between ERα and ERβ and between PR and ERβ protein expression. As for ERα36, EGFR and HER2, there was a significant positive correlation between ERα36, EGFR and HER2 protein expression in PTCs. Concomitant high expression of ERα36, EGFR and HER2 was strongly associated with aggressive behaviors including extrathyroidal extension (ETE), lymph node metastasis (LNM) and high TNM stage in PTCs (P < 0.001).

Bisphenol A and estrogen induce proliferation of human thyroid tumor cells via an estrogen-receptor-dependent pathway

OBJECTIVE

To determine the relationship between papillary thyroid carcinoma and environmental exposure to bisphenol A (BPA) or 17-β estrogen (E₂) by assessing the effects of these compounds on estrogen receptor expression and AKT/mTOR signaling.

METHODS

The effects of low levels of BPA (1mM-10nM) and 17β-estradiol (E2, 0.1mM-1nM) on ER expression and cellular proliferation were determined in human thyroid papillary cancer BHP10-3 cells. Protein and mRNA levels of estrogen nuclear receptors (ERα/ERβ) and membrane receptors (GPR30) were determined by immunofluorescence assay, Western blotting, and RT-PCR, respectively, and proliferation was assessed by CCK-8 assay.

RESULTS

The proliferative effects of BPA and E₂ were both concentration- and time-dependent. Expression of ERα/ERβ and GPR30 were enhanced by BPA and E_2. BPA and E₂ could quickly phosphorylate AKT/mTOR. Moreover, ICI suppressed ERα expression and activated GPR30 as did G-1. G-15 reversed the effects of E₂ on GPR30 and AKT/mTOR, but did not alter the effect of BPA.

CONCLUSIONS

BPA influences thyroid cancer proliferation by regulating expression of ERs and GPR30, a mechanism that differs from E₂. In addition, ICI and G-15 may have the potential to be used as anti-thyroid cancer agents.

GPER/ERK&AKT/NF-κB pathway is involved in cadmium-induced proliferation, invasion and migration of GPER-positive thyroid cancer cells

The higher incidence of thyroid cancer in women during reproductive years compared with men and the increased risk associated with the therapeutic use of estrogen have strongly suggested that estrogen may be involved in the occurrence and development of thyroid cancer. Cadmium (Cd) is a potent metalloestrogen that disrupts the endocrine system by mimicking the effects of 17β-estradiol (E2). In the present study, we demonstrate that similar to E2 and G1, a specific agonist for G protein-coupled estrogen receptor (GPER), Cd induces the proliferation, invasion and migration of human WRO and FRO thyroid cancer cells that have endogenous GPER. Moreover, like E2 and G1, Cd leads to a rapid activation of ERK/AKT, and then nuclear translocation of NF-κB, increased expression of cyclin A and D1, and secretion of IL-8, all of which are significantly attenuated by GPER blockage or knock-down in both WRO and FRO cells. Furthermore, the Cd-induced proliferation, invasion and migration are suppressed either by specific inhibitors for GPER, ERK, AKT and NF-κB, or by knock-down of GPER. These results suggest that GPER/ERK&AKT/NF-κB signaling pathway is involved in the Cd-induced proliferation, invasion and migration of GPER-positive thyroid cancer cells.

The levels of the sex hormones are not different between type 1 and type 2 endometrial cancer

The involvement of hormonal factors in developing endometrial cancer is well documented. In particular, excess or unopposed estrogen is a major risk factor. Endometrial cancer is divided into estrogen-dependent and estrogen-independent types. Studies suggested that the subtypes of endometrial cancer share many common risk factors. Whether the levels of sex hormones differ between types 1 and 2 endometrial cancer has not been investigated. In this study, levels of estrogen, progesterone, testosterone, follicle stimulating hormone (FSH) and luteinizing hormone (LH) were investigated between type 1 and type 2 endometrial cancer taking into account menopausal status and parity. The sex hormones levels and estrogen and progesterone receptors were measured in 187 women with endometrial cancer. The levels of estradiol (E2), progesterone, testosterone, FSH and LH were not different between the subtypes of endometrial cancer regardless of menopausal status. In addition, the sex hormones were not different between patients of different party regardless of the menopausal status. The majority of type 1 (96%) and type 2 (82%) endometrial cancers were estrogen and progesterone receptor positive. Our data suggest that type 2 endometrial cancer is not completely estrogen independent, and type 1 and type 2 endometrial cancers may have a similar pathogenesis.

Up-regulation of Hsp27 by ERα/Sp1 facilitates proliferation and confers resistance to apoptosis in human papillary thyroid cancer cells

17β-estradiol (E2) has been suggested to play a role in the development and progression of papillary thyroid cancer. Heat shock protein 27 (Hsp27) is a member of the Hsp family that is responsible for cell survival under stressful conditions. Previous studies have shown that the 5'-promoter region of Hsp27 gene contains a specificity protein-1 (Spl) and estrogen response element half-site (ERE-half), which contributes to Hsp27 induction by E2 in breast cancer cells. However, it is unclear whether Hsp27 can be up-regulated by E2 and which estrogen receptor (ER) isoform and tethered transcription factor are involved in this regulation in papillary thyroid cancer cells. In the present study, we demonstrated that Hsp27 can be effectively up-regulated by E2 at mRNA and protein levels in human K1 and BCPAP papillary thyroid cancer cells which have more than two times higher level of ERα than that of ERβ. The up-regulation of Hsp27 by E2 is mediated by ERα/Sp1 and ERβ has repressive effect on this ERα/Sp1-mediated up-regulation of Hsp27. Moreover, we showed that the up-regulation of Hsp27 by ERα/Sp1 facilitates proliferation and confers resistance to apoptosis through interaction with procaspase-3. Targeting this pathway may be a potential strategy for therapy of papillary thyroid cancer.

The Impact of Diagnostic Changes on the Rise in Thyroid Cancer Incidence: A Population-Based Study in Selected High-Resource Countries

BACKGROUND

Thyroid cancer (TC) incidence is rising in many countries, but the corresponding mortality is constant or declining. Incidence increases appear largely restricted to small papillary TC in young/middle-age individuals. We compared age-specific incidence rates across countries and time periods in order to estimate the fraction of TC possibly attributable to increased surveillance of the thyroid gland (diagnostic changes) following the introduction of neck ultrasonography in the 1980s.

METHODS

We focused on high-resource countries, including four Nordic countries, England and Scotland, France, Italy, the United States, Australia, Japan, and the Republic of Korea. Before the 1970s, TC incidence in Nordic countries increased proportionally to the second power of age, consistent with the multistage model of carcinogenesis. Using this historical observation for reference, we attributed the progressive departure from linearity of the age curves in each country to an increased detection of asymptomatic disease in young/middle-age individuals. The proportion of cases attributable to diagnostic changes was estimated from the difference between observed rates and those expected using the Nordic countries as reference.

RESULTS

Diagnostic changes may account for ≥60% of TC cases diagnosed in 2003-2007 in women aged under 80 years in France, Italy, the United States, Australia, and the Republic of Korea, and approximately 50% in other assessed countries, except Japan (30%). The proportions attributable to diagnostic changes were higher in countries with largest incidence increases and were consistent across sexes, although increases were smaller and delayed in men.

CONCLUSIONS

A large proportion of TC cases diagnosed in high-resource countries in the last two decades are likely to be due to diagnostic changes. This proportion has progressively increased over time, and it is likely to grow further in the future. Since there is evidence of harm but no proof of benefit from the intense scrutiny of the thyroid, the dangers of overdiagnosis and overtreatment of TC should be urgently addressed.

Targeted DNA Methylation Screen in the Mouse Mammary Genome Reveals a Parity-Induced Hypermethylation of Igf1r That Persists Long after Parturition

The most effective natural prevention against breast cancer is an early first full-term pregnancy. Understanding how the protective effect is elicited will inform the development of new prevention strategies. To better understand the role of epigenetics in long-term protection, we investigated parity-induced DNA methylation in the mammary gland. FVB mice were bred or remained nulliparous and mammary glands harvested immediately after involution (early) or 6.5 months following involution (late), allowing identification of both transient and persistent changes. Targeted DNA methylation (109 Mb of Ensemble regulatory features) analysis was performed using the SureSelectXT Mouse Methyl-seq assay and massively parallel sequencing. Two hundred sixty-nine genes were hypermethylated and 128 hypomethylated persistently at both the early and late time points. Pathway analysis of the persistently differentially methylated genes revealed Igf1r to be central to one of the top identified signaling networks, and Igf1r itself was one of the most significantly hypermethylated genes. Hypermethylation of Igf1r in the parous mammary gland was associated with a reduction of Igf1r mRNA expression. These data suggest that the IGF pathway is regulated at multiple levels during pregnancy and that its modification might be critical in the protective role of pregnancy. This supports the approach of lowering IGF action for prevention of breast cancer, a concept that is currently being tested clinically.

Breast and prostate cancer: an analysis of common epidemiological features in mortality trends in Spain

BACKGROUND

Breast cancer in women and prostate cancer are the first and second leading tumour respectively in terms of incidence world-wide. Our objective is to ascertain the similarities and differences between mortality trends in breast cancer among women and prostate cancer in Spain using age-period-cohort models, and analyse the correlation between incidence of breast and prostate cancer at cancer registries locally and world-wide.

METHODS

We analysed the independent effects of age, period of death and birth cohort on mortality rates for breast cancer in women and prostate cancer in Spain across the period 1952-2011. Segmented regression analyses were performed to detect and estimate changes in period and cohort curvatures. Correlation among age-adjusted incidence rates at 246 population cancer registries world-wide was analysed for the period 2003-2007.

RESULTS

The mortality trend displayed common characteristics in terms of the annual number of deaths due to these tumours, their adjusted mortality rates and the change points detected in the cohort and period effects. The trend in incidence was very different to that in mortality, due to early detection and progressive improvement in survival. Correlation between the incidence rates of both tumours recorded by registries around the world proved to be a generalised phenomenon.

CONCLUSIONS

This study shows that breast cancer mortality in women and prostate cancer mortality and their trends in Spain display visible similarities in terms of the number of deaths due to these tumours, their adjusted mortality rates and the changes experienced by mortality over time. The effects of advances in the diagnosis of both tumours correspond to a decline in mortality which becomes evident after a lag of approximately eight years. Correlation between breast and prostate cancer incidence rates is very high in Spain and at registries on all continents.

Is oestrogen an important player in melanoma progression?

The oestrogen-dependent regulation of cell behaviour is realised by stimulation of specific oestrogen receptors. The classical oestrogen receptors ERα and ERβ are transcription factors, and they modulate expression of hormonally regulated genes, while the third one, GPER, is thought to be responsible for the observed rapid, non-genomic cellular response. Oestrogen dependency is attributed to a number of cancers, including breast, ovarian and endometrial cancer; however, there is still growing evidence that melanoma should also be cited as a hormonally dependent tumour. This comes from the observations of gender-related differences in melanoma progression and reports concerning the history of the malignant course of melanomas during pregnancy. Although, the observations of oestrogen regulation of melanoma progression are controversial, the effect of oestrogen should not be neglected, as the skin possesses its own hormonal microenvironment. This aspect of melanoma progression should be taken under careful consideration as it may offer new therapeutic possibilities.

Chromatin composition alterations and the critical role of MeCP2 for epigenetic silencing of progesterone receptor-B gene in endometrial cancers

OBJECTIVE

To understand the epigenetic mechanism underlying the PR-B gene silencing in endometrial cancer (EC) cells, we compared the chromatin composition between transcriptionally active and silenced PR-B genes in EC cell lines and cancer tissues.

METHODS

Chromatin Immunoprecipitation (ChIP) assay was performed to measure MBD occupancy and histone acetylation/methylation in transcriptionally active and silenced PR-B genes. PR-B-positive/-negative, as well as epigenetic inhibitor-treated/-untreated EC cells were used as study models. Real-time polymerase chain reaction (PCR) and Western blot analysis were applied to measure the mRNA and protein levels of PR-B, MBD, and histones.

RESULTS

A close association among PR-B methylation, MBD binding and PR-B gene silencing was observed. Treatment with epigenetic inhibitors led to dynamic changes in the PR-B chromatin composition and gene expression. Increased H3/H4 acetylation and H3-K4 methylation, and decreased H3-K9 methylation were found to be associated with re-activation of silenced PR-B genes. MeCP2 knockdown resulted in a decreased MeCP2 binding to PR-B genes and an increased PR-B expression. ChIP analysis of MeCP2 binding to PR-B genes in the PR-B-positive/-negative EC samples confirmed the significant role of MeCP2 in PR-B silencing.

CONCLUSION

PR-B gene expression is regulated by a concerted action of epigenetic factors including DNA methylation, MBD binding, and histone modifications. MeCP2 occupancy of PR-B genes plays a critical role in PR-B gene silencing. These findings enriched our knowledge of the epigenetic regulation of PR-B expression in EC, and suggested that the epigenetic re-activation of PR-B could be explored as a potential strategy to sensitize the PR-B-negative endometrial cancers to progestational therapy.

Time trends in municipal distribution patterns of cancer mortality in Spain

BACKGROUND

New disease mapping techniques widely used in small-area studies enable disease distribution patterns to be identified and have become extremely popular in the field of public health. This paper reports on trends in the geographical mortality patterns of the most frequent cancers in Spain, over a period of 20 years.

METHODS

We studied the municipal spatial pattern of stomach, colorectal, lung, breast, prostate and urinary bladder cancer mortality in Spain across four quinquennia, spanning the period 1989-2008. Case data were broken down by town (8073 municipalities), period and sex. Expected cases for each town were calculated using reference rates for each five-year period. For map plotting purposes, smoothed municipal relative risks were calculated using the conditional autoregressive model proposed by Besag, York and Mollié, with independent data for each quinquennium. We evaluated the presence of spatial patterns in maps on the basis of models, calculating the variance in relative risk corresponding to the structured spatial component and the unstructured component, as well as the proportion of variance explained by the structured spatial component.

RESULTS

The mortality patterns observed for stomach, colorectal and lung cancer were maintained over the 20 years covered by the study. Prostate cancer and the tumours studied in women showed no defined spatial pattern, with the single exception of stomach cancer. The trend in spatial fractional variance indicated the possibility of a change in the spatial pattern in breast, bladder and colorectal cancer in women during the last five-year period. The paper goes on to discuss ways in which spatio-temporal data are depicted in the case of cancer, and review the risk factors that may possibly influence the respective tumours' spatial patterns.

CONCLUSION

In men, the marked geographical patterns of stomach, colorectal, lung and bladder cancer remained stable over time. Breast, colorectal and bladder cancer in women show signs of the possible appearance of a spatial pattern in Spain and should therefore be monitored.

In situ breast cancer and microchimerism

Microchimeric cells of fetal origin persistent in the maternal circulation post-partum are associated with protection against invasive breast cancer. Here using quantitative genomic methods, we evaluated for the presence of male fetal microchimerism in buffy coat cells from women with a prior history of breast carcinomas in situ (CIS) and in healthy controls. Fetal microchimerism was detected in 75 of 88 controls (85%) and in 57 of 89 CIS patients (64%). The odds ratio for protection against non-invasive breast disease was 0.26 (95% confidence interval 0.12-0.56; p < 0.001 adjusted for age and body mass index). Similar to women with invasive breast cancer, women with CIS who are naturally at high risk for future invasive disease were deficient for fetal microchimerism. In addition to autologous anti-tumor immune responses, the maintenance of haploidentical microchimerism may impart an allogeneic edge in immunosurveillance.

BRCA and Early Events in the Development of Serous Ovarian Cancer

Women who have an inherited mutation in the BRCA1 or BRCA2 genes have a substantial increased lifetime risk of developing epithelial ovarian cancer (EOC), and epidemiological factors related to parity, ovulation, and hormone regulation have a dramatic effect on the risk in both BRCA mutation carriers and non-carriers. The most common and most aggressive histotype of EOC, high-grade serous carcinoma (HGSC), is also the histotype associated with germline BRCA mutations. In recent years, evidence has emerged indicating that the likely tissue of origin of HGSC is the fallopian tube. We have reviewed, what is known about the fallopian tube in BRCA mutation carriers at both the transcriptional and translational aspect of their biology. We propose that changes of the transcriptome in BRCA heterozygotes reflect an altered response to the ovulatory stresses from the microenvironment, which may include the post-ovulation inflammatory response and altered reproductive hormone physiology.

Worldwide trends in cervical cancer incidence: impact of screening against changes in disease risk factors

BACKGROUND

Cervical cancer trends in a given country mainly depend on the existence of effective screening programmes and time changes in disease risk factors, notably exposure to human papillomavirus (HPV). Screening primarily influences variations by period of diagnosis, whereas changes in risk factors chiefly manifest themselves as variations in risk across successive birth cohorts of women.

METHODS

We assessed trends in cervical cancer across 38 countries in five continents, age group 30-74 years, using age-standardised incidence rates (ASRs) and age-period-cohort (APC) models. Non-identifiability in APC models was circumvented by making assumptions based on a consistent relationship between age and cervical cancer incidence (i.e. approximately constant rates after age 45 years).

FINDINGS

ASRs decreased in several countries, except in most of Eastern European populations, Thailand as well as Uganda, although the direction and magnitude of period and birth cohort effects varied substantially. Strong downward trends in cervical cancer risk by period were found in the highest-income countries, whereas no clear changes by period were found in lower-resourced settings. Successive generations of women born after 1940 or 1950 exhibited either an increase in risk of cervical cancer (in most European countries, Japan, China), no substantial changes (North America and Australia) or a decrease (Ecuador and India).

INTERPRETATION

In countries where effective screening has been in place for a long time the consequences of underlying increases in cohort-specific risk were largely avoided. In the absence of screening, cohort-led increases or, stable, cervical cancer ASRs were observed. Our study underscores the importance of strengthening screening efforts and augmenting existing cancer control efforts with HPV vaccination, notably in those countries where unfavourable cohort effects are continuing or emerging.

FUNDING

Bill and Melinda Gates Foundation (BMGF).

Does mammographic density reflect the expression of breast cancer markers?

Mammographic density reflects variation in breast tissue composition as detected on mammogram. It is associated with a number of well-known breast cancer risk factors and itself is considered one of the strongest risk factors for breast cancer. If the expression of several proteins and genes within the breast tissue influences mammographic density in the same way as it influences breast cancer risk, then mammographic density might serve as an intermediate biomarker in future epidemiological studies on breast cancer. This has the potential to provide a quick means for predicting the effect of changes in the breast microenvironment on breast cancer risk without having to wait for an eventual development of breast cancer. In this review, the expression of several proteins and genes (growth factors, enzymes, proteoglycans and pro-inflammatory markers) within the breast tissue is shown to be associated with mammographic density. These proteins and genes are suspected to play a role in breast carcinogenesis. More studies assessing differential expression of proteins and genes in mammary epithelium and stroma and their association with mammographic density among premenopausal and postmenopausal women are required. Identification of proteins and genes influencing mammographic density may provide further insight on the molecular causes of breast cancer.

Cigarette smoking and endometrial cancer risk: the modifying effect of obesity

The objective of this study was to evaluate the association between cigarette smoking and endometrial cancer risk by investigating potential modifying effects of menopausal status, obesity, and exogenous hormones. We pooled data from three case-control studies with the same study design conducted in Italy and Switzerland between 1982 and 2006. Overall, 1446 incident endometrial cancers and 4076 hospital controls were enrolled. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using logistic regression models, conditioned on study and centre, and adjusted for age, period of interview, age at menarche, parity, and body mass index. In comparison with never smokers, current smokers showed reduced endometrial cancer risk (OR: 0.80; 95% CI: 0.66-0.96), with a 28% decrease in risk for smoking ≥ 20 cigarettes/day. The association did not vary according to menopausal status, oral contraceptive use, or hormone replacement therapy. However, heterogeneity emerged according to body mass index among postmenopausal women, with obese women showing the greatest risk reduction for current smoking (OR: 0.47; 95% CI: 0.27-0.81). In postmenopausal women, obesity turned out to be an important modifier of the association between cigarette smoking and the risk of endometrial cancer. This finding calls for caution in interpreting the favorable effects of cigarette smoking, considering the toxic and carcinogenic effects of tobacco.

The epidemiology and molecular mechanisms linking obesity, diabetes, and cancer

The worldwide epidemic of obesity is associated with increasing rates of the metabolic syndrome and type 2 diabetes. Epidemiological studies have reported that these conditions are linked to increased rates of cancer incidence and mortality. Obesity, particularly abdominal obesity, is associated with insulin resistance and the development of dyslipidemia, hyperglycemia, and ultimately type 2 diabetes. Although many metabolic abnormalities occur with obesity and type 2 diabetes, insulin resistance and hyperinsulinemia appear to be central to these conditions and may contribute to dyslipidemia and altered levels of circulating estrogens and androgens. In this review, we will discuss the epidemiological and molecular links between obesity, type 2 diabetes, and cancer, and how hyperinsulinemia and dyslipidemia may contribute to cancer development. We will discuss how these metabolic abnormalities may interact with estrogen signaling in breast cancer growth. Finally, we will discuss the effects of type 2 diabetes medications on cancer risk.

Acting on Hormone Receptors with Minimal Side Effect on Cell Proliferation: A Timely Challenge Illustrated with GLP-1R and GPER

G protein-coupled receptors (GPCRs) constitute a large family of receptors that sense molecules outside the cell and activate inside signal transduction pathways and cellular responses. GPCR are involved in a wide variety of physiological processes, including in the neuroendocrine system. GPCR are also involved in many diseases and are the target of 30% of marketed medicinal drugs. Whereas the majority of the GPCR-targeting drugs have proved their therapeutic benefit, some of them were associated with undesired effects. We develop two examples of used drugs whose therapeutic benefits are tarnished by carcinogenesis risks. The chronic administration of glucagon-like peptide-1 (GLP-1) analogs widely used to treat type-2 diabetes was associated with an increased risk of pancreatic or thyroid cancers. The long-term treatment with the estrogen antagonist tamoxifen, developed to target breast cancer overexpressing estrogen receptors ER, presents agonist activity on the G protein-coupled estrogen receptor which is associated with an increased incidence of endometrial cancer and breast cancer resistance to hormonotherapy. We point out and discuss the need of pharmacological studies to understand and overcome the undesired effects associated with the chronic administration of GPCR ligands. In fact, biological effects triggered by GPCR often result from the activation of multiple intracellular signaling pathways. Deciphering which signaling networks are engaged following GPCR activation appears to be primordial to unveil their contribution in the physiological and physiopathological processes. The development of biased agonists to elucidate the role of the different signaling mechanisms mediated by GPCR activation will allow the generation of new therapeutic agents with improved efficacy and reduced side effects. In this regard, the identification of GLP-1R biased ligands promoting insulin secretion without inducing pro-tumoral effects would offer therapeutic benefit.

Relationships among serum CA15-3 tumor marker, TNM staging, and estrogen and progesterone receptor expression in benign and malignant breast lesions

Serum tumor marker CA15-3 is widely used in follow-up for assessment of breast cancer prognosis. The aim of this study was to evaluate levels among healthy females and patients, to assess differences with tumor stage and grade, and to determine the relationship with estrogen and progesterone receptor expression. One hundred and thirty six Jordanian females were enrolled in this study: Forty-five were healthy females; seventy-two were diagnosed with breast cancer and nineteen diagnosed with benign breast lesions. Elevated serum CA15-3 level was significantly observed among breast cancer patients (37.95±6.65) compared to both healthy (14.97±0.8) and benign females (12.30±1.55), but no significant association was detected between serum CA15-3 level and age of cancer onset, menarche age, menopause age, parity and BMI. Decreased CA15-3 level was significantly associated with hormone therapy and oral contraceptive consumption among breast cancer patients. Significantly elevated CA15-3 serum levels were found among grade II, III and stage II and III breast cancer females compared to normal healthy females. Elevated CA15-3 serum levels were also found among ER+/PR+ (54.242±7.89) and ER+/PR- (37.08±8.22) compared to healthy control females.

Estradiol, tamoxifen, and flaxseed alter IL-1β and IL-1Ra levels in normal human breast tissue in vivo

INTRODUCTION

Sex steroid exposure increases the risk of breast cancer by unclear mechanisms. Diet modifications may be one breast cancer prevention strategy. The proinflammatory cytokine family of IL-1 is implicated in cancer progression. IL-1Ra is an endogenous inhibitor of the proinflammatory IL-1α and IL-1β.

OBJECTIVE

The objective of this study was to elucidate whether estrogen, tamoxifen, and/or diet modification altered IL-1 levels in normal human breast tissue.

DESIGN AND METHODS

Microdialysis was performed in healthy women under various hormone exposures, tamoxifen therapy, and diet modifications and in breast cancers of women before surgery. Breast tissue biopsies from reduction mammoplasties were cultured.

RESULTS

We show a significant positive correlation between estradiol and in vivo levels of IL-1β in breast tissue and abdominal sc fat, whereas IL-1Ra exhibited a significant negative correlation with estradiol in breast tissue. Tamoxifen or a dietary addition of 25 g flaxseed per day resulted in significantly increased levels of IL-1Ra in the breast. These results were confirmed in ex vivo culture of breast biopsies. Immunohistochemistry of the biopsies did not reveal any changes in cellular content of the IL-1s, suggesting that mainly the secreted levels were affected. In breast cancer patients, intratumoral levels of IL-1β were significantly higher compared with normal adjacent breast tissue.

CONCLUSION

IL-1 may be under the control of estrogen in vivo and may be attenuated by antiestrogen therapy and diet modifications. The increased IL-1β in breast cancers of women strongly suggests IL-1 as a potential therapeutic target in breast cancer treatment and prevention.

Polyphenols, isothiocyanates, and carotenoid derivatives enhance estrogenic activity in bone cells but inhibit it in breast cancer cells

While exposure to estrogens is a major risk factor of breast and endometrial cancer, it well established that estrogens are beneficial for bone health. We have previously shown that carotenoids inhibit estrogen signaling in breast and endometrial cancer cells. The aim of this study was to compare the effects of various phytonutrients, (carotenoid derivatives, polyphenols, isothiocyanates) on estrogenic activity in breast cancer cells and osteoblast-like cells. All the tested phytonutrients inhibited estrogen response element (ERE) transactivation in breast cancer cells. In contrast, these compounds either did not affect or enhanced ERE activity and the expression of several bone-forming genes. These results were obtained using two osteoblast-like cell lines, MG-63 human osteosarcoma cells stably transfected with estrogen receptor-α (ERα) and MC3T3-E1 mouse calvaria-derived cells expressing endogenous ER. Phytonutrients-induced ERE inhibition in breast cancer cells, and its potentiation in osteoblast-like cells were associated both with a decrease and a rise in total and nuclear ERα levels, respectively. Phytonutrients activated the electrophile/antioxidant response element (EpRE/ARE) transcription system to various extents in both cancer and bone cell lines. Overexpression of Nrf2, the major EpRE/ARE activating transcription factor, mimicked the effects of phytonutrients, causing inhibition and enhancement of ERE transactivation in breast cancer cells and in osteoblast-like cells, respectively. Moreover, reduction in Nrf2 levels by RNAi led to a decrease in the phytonutrient potentiation of ERE activity transactivation in osteoblast-like cells. These findings suggest that the enhancement and inhibition of estrogen signaling by phytonutrients in bone-derived cells and breast cancer cells, respectively, is partially mediated by the activation of the Nrf2/ARE system.

The role of obesity in cancer survival and recurrence

Obesity and components of energy imbalance, that is, excessive energy intake and suboptimal levels of physical activity, are established risk factors for cancer incidence. Accumulating evidence suggests that these factors also may be important after the diagnosis of cancer and influence the course of disease, as well as overall health, well-being, and survival. Lifestyle and medical interventions that effectively modify these factors could potentially be harnessed as a means of cancer control. However, for such interventions to be maximally effective and sustainable, broad sweeping scientific discoveries ranging from molecular and cellular advances, to developments in delivering interventions on both individual and societal levels are needed. This review summarizes key discussion topics that were addressed in a recent Institute of Medicine Workshop entitled, "The Role of Obesity in Cancer Survival and Recurrence"; discussions included (i) mechanisms associated with obesity and energy balance that influence cancer progression; (ii) complexities of studying and interpreting energy balance in relation to cancer recurrence and survival; (iii) associations between obesity and cancer risk, recurrence, and mortality; (iv) interventions that promote weight loss, increased physical activity, and negative energy balance as a means of cancer control; and (v) future directions.

Insulin-like growth factor-I regulates GPER expression and function in cancer cells

Functional cross talk between insulin-like growth factor-I (IGF-I) system and estrogen signaling has been largely reported, although the underlying molecular mechanisms remain to be fully elucidated. As GPR30/GPER mediates rapid cell responses to estrogens, we evaluated the potential of IGF-I to regulate GPER expression and function in estrogen receptor (ER)α-positive breast (MCF-7) and endometrial (Ishikawa) cancer cells. We found that IGF-I transactivates the GPER promoter sequence and upregulates GPER mRNA and protein levels in both cells types. Similar data were found, at least in part, in carcinoma-associated fibroblasts. The upregulation of GPER expression by IGF-I involved the IGF-IR/PKCδ/ERK/c-fos/AP1 transduction pathway and required ERα, as ascertained by specific pharmacological inhibitors and gene-silencing. In both MCF-7 and Ishikawa cancer cells, the IGF-I-dependent cell migration required GPER and its main target gene CTGF, whereas the IGF-I-induced proliferation required both GPER and cyclin D1. Our data demonstrate that the IGF-I system regulates GPER expression and function, triggering the activation of a signaling network that leads to the migration and proliferation of cancer cells.

Mediterranean climate is associated with early age at menopause and low high-density lipoprotein in postmenopausal women

OBJECTIVE

The aim of this study was to investigate the effect of three different climates on age at menopause and metabolic factors in postmenopausal women.

METHODS

Study population consisted of 232 postmenopausal women with natural menopause who admitted to Dr. Sami Ulus Maternity and Women's Health Teaching and Research Hospital Menopause outpatient clinic for routine check up. Participants were divided into three groups according to climate where they had lived during reproductive span. Black Sea, Mediterranean, and continental climate effects on age at menopause and metabolic factors were investigated.

RESULTS

Postmenopausal women living in three different climates were significantly different according to body mass index, gravidity, age at menopause, menarche, and high-density lipoprotein (HDL) (p < 0.05). The lowest mean age at menopause and HDL levels were observed in women living in Mediterranean climate. Adjusted mean age at menopause remained significant (p < 0.05).

CONCLUSION

Mediterranean climate is associated with early menopause and low HDL levels.

Endogenous sex steroids and risk of cervical carcinoma: results from the EPIC study

BACKGROUND

Epidemiologic data and animal models suggest that, despite the predominant role of human papillomavirus infection, sex steroid hormones are also involved in the etiology of invasive cervical carcinoma (ICC).

METHODS

Ninety-nine ICC cases, 121 cervical intraepithelial neoplasia grade 3 (CIN3) cases and 2 control women matched with each case for center, age, menopausal status and blood collection-related variables, were identified in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Circulating levels of testosterone (T) and estradiol (E(2)); dehydroepiandrosterone sulfate (DHEAS); progesterone (premenopausal women); and sex hormone-binding globulin (SHBG) were measured using immunoassays. Levels of free (f) T and E(2) were calculated from absolute concentrations of T, E(2), and SHBG. Odds ratios (ORs) and 95% confidence intervals (CI) were computed using regularized conditional logistic regression.

RESULTS

Among premenopausal women, associations with ICC were observed for fT (OR for highest vs. lowest tertile = 5.16, 95% CI, 1.50-20.1). SHBG level was associated with a significant downward trend in ICC risk. T, E(2), fE(2), and DHEAS showed nonsignificant positive association with ICC. Progesterone was uninfluential. Among postmenopausal women, associations with ICC were found for T (OR = 3.14; 95% CI, 1.21-9.37), whereas E(2) and fT showed nonsignificant positive association. SHBG level was unrelated to ICC risk in postmenopausal women. No associations between any hormone and CIN3 were detected in either pre- or postmenopausal women.

CONCLUSIONS

Our findings suggest for the first time that T and possibly E(2) may be involved in the etiology of ICC.

IMPACT

The responsiveness of cervical tumors to hormone modulators is worth exploring.

Tamoxifen and flaxseed alter angiogenesis regulators in normal human breast tissue in vivo

The incidence of breast cancer is increasing in the Western world and there is an urgent need for studies of the mechanisms of sex steroids in order to develop novel preventive strategies. Diet modifications may be among the means for breast cancer prevention. Angiogenesis, key in tumor progression, is regulated by the balance between pro- and anti-angiogenic factors, which are controlled in the extracellular space. Sampling of these molecules at their bioactive compartment is therefore needed. The aims of this study were to explore if tamoxifen, one of the most used anti-estrogen treatments for breast cancer affected some of the most important endogenous angiogenesis regulators, vascular endothelial growth factor (VEGF), angiogenin, and endostatin in normal breast tissue in vivo and if a diet supplementation with flaxseed had similar effects as tamoxifen in the breast. Microdialysis was used for in situ sampling of extracellular proteins in normal breast tissue of women before and after six weeks of tamoxifen treatment or before and after addition of 25 g/day of ground flaxseed to the diet or in control women. We show significant correlations between estradiol and levels of VEGF, angiogenin, and endostatin in vivo, which was verified in ex vivo breast tissue culture. Moreover, tamoxifen decreased the levels of VEGF and angiogenin in the breast whereas endostatin increased significantly. Flaxseed did not alter VEGF or angiogenin levels but similar to tamoxifen the levels of endostatin increased significantly. We conclude that one of the mechanisms of tamoxifen in normal breast tissue include tipping of the angiogenic balance into an anti-angiogenic state and that flaxseed has limited effects on the pro-angiogenic factors whereas the anti-angiogenic endostatin may be modified by diet. Further studies of diet modifications for breast cancer prevention are warranted.

Menopausal hormone therapy and risk of gastrointestinal cancer: nested case-control study within a prospective cohort, and meta-analysis

Use of menopausal hormone therapy (HT) has been associated with reduced risk of colorectal cancer; evidence for its effect on other gastrointestinal cancers is limited. We conducted a nested case-control study within a UK cohort, and meta-analyses combining our results with those from published studies. Our study included women aged 50+ in the UK General Practice Research Database (GPRD): 1,054 with oesophageal, 750 with gastric and 4,708 with colorectal cancer, and 5 age- and practice-matched controls per case. Relative risks (RRs) and 95% confidence intervals (CIs) for cancer in relation to prospectively-recorded HT prescriptions were estimated by conditional logistic regression. Women prescribed HT had a reduced risk of oesophageal cancer (adjusted RR for 1+ vs. no HT prescriptions, 0.68, 95% CI 0.53-0.88; p = 0.004), gastric cancer (0.75, 0.54-1.05; p = 0.1) and colorectal cancer (0.81, 0.73-0.90; p < 0.001). There were no significant differences in cancer risk by HT type, estimated duration of HT use or between past and current users. In meta-analyses, risks for ever vs. never use of HT were significantly reduced for all three cancers (summary RR for oesophageal cancer, 0.68, 0.55-0.84, p < 0.001; for gastric cancer, 0.78, 0.65-0.94, p = 0.008; for colorectal cancer, 0.84, 0.81-0.88, p < 0.001). In high-income countries, estimated incidence over 5 years of these three cancers combined in women aged 50-64 was 2.9/1,000 in HT users and 3.6/1,000 in never users. The absolute reduction in risk of these cancers in HT users is small compared to the HT-associated increased risk of breast cancer.

Time since first sexual intercourse and the risk of cervical cancer

Young age at first sexual intercourse (AFI) is an important risk factor for cervical cancer, but no simple statistical model of its influence has been established. We investigated the relationship between risk of cervical carcinoma and time since first intercourse using data on monogamous women (5,074 cases and 16,137 controls) from the International Collaboration of Epidemiological Studies of Cervical Cancer. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated from pooled data on 20 studies using conditional logistic regression. The OR for invasive cervical carcinoma is approximately proportional to the square of time since first intercourse (exponent 1.95, 95% CI: 1.76-2.15) up to age 45. First cervical infection with human papillomavirus (HPV) often occurs soon after first sexual intercourse, so early AFI is a reasonable proxy for early age at first exposure to HPV. In addition, age-specific incidence rates of cervical cancer in unscreened populations remain fairly constant above age 45. Cervical cancer thus resembles other cancers caused by strong early-stage carcinogens, with incidence rates proportional to a power of time since first exposure and also resembles cancers of the breast and other hormone-dependent epithelia, where a similar flattening of age-specific incidence rates is seen at the time menopausal changes start. Taken together, these observations suggest that HPV vaccination may prevent the majority of cervical cancers by delaying HPV infection without necessarily providing lifetime protection against HPV.

Long-term overweight and weight gain in early adulthood in association with risk of endometrial cancer

Long-term overweight and substantial weight gain over adulthood are known risk factors of endometrial cancer, but the timing of weight gain in relation to risk and the effect of weight change on age at diagnosis remain unclear. A population-based case-control study was conducted to evaluate the long-term effect of body weight on endometrial cancer risk. The study enrolled 668 incident cases and 674 population controls. Anthropometric features in each decade of adult life were ascertained through in-person interview and analyzed for their associations with endometrial cancer using unconditional logistic regression. As expected, high body mass index (BMI) was significantly associated with increased risk. Women who were overweight or obese at the time of interview had adjusted odds ratios of 1.54 (95%CI 1.13-2.10) and 4.76 (95%CI 3.50-6.49), respectively, compared to women of normal weight. Similar associations were observed for BMI assessed at each decade of adult life. More importantly, women who were overweight (BMI ≥ 25) in their 20s or 30s and maintained the overweight throughout life had significantly higher risk than those who became overweight at ages 40s or 50s. Women with substantial weight gain (≥35%) in early adulthood (age 20s) developed the disease 10 years earlier than those without such weight change in early life. These observations further confirm the critical link between body weight and development of endometrial cancer.