The effect of major epidemiologic risk factors for ovarian cancer has been reviewed in the light of several hormonal hypotheses,
including the gonadotropin, androgens, progesterone, estrogens, ...insulin-like growth factor-I, and insulin hypotheses. The
role of inclusion cyst formation and Mullerian epithelium differentiation in the pathology of the disease are also briefly
outlined. Although based on limited data, the observed tendency in current evidence suggests possible etiologic roles for
elevated androgens and estrogens and decreased progesterone in the pathogenesis of ovarian cancer. A direct effect of gonadotropins
cannot be entirely ruled out, but it is plausible that their effect on ovarian cancer risk is mediated by stimulation of ovarian
steroidogenesis. Insulin-like growth factor-I also emerges as a hormone that may be directly involved in the pathogenesis
of the disease, but thus far only one prospective study has examined this association. Hyperinsulinemia is an unlikely risk
factor for ovarian cancer. The observed tendency for an increased risk with androgens from ovarian origin (in premenopausal
women), the lack of association with adrenal androgens, and the relatively weak associations observed with obesity, hormonal
replacement therapy use, and endogenous hormones after menopause suggest that ovarian synthesis of sex steroids rather than
their circulating levels may be etiologically important. More data from prospective studies will be crucial to improve our
understanding of the etiologic role of endogenous hormones in the pathogenesis of ovarian cancer. Such data will ultimately
provide opportunities for research targeted; at early detection and preventive interventions.
DNA methylation is a dynamic and reversible process that governs gene expression during development and disease. Several examples of active DNA demethylation have been documented, involving ...genome-wide and gene-specific DNA demethylation. How demethylating enzymes are targeted to specific genomic loci remains largely unknown. We show that an antisense lncRNA, termed TARID (for TCF21 antisense RNA inducing demethylation), activates TCF21 expression by inducing promoter demethylation. TARID interacts with both the TCF21 promoter and GADD45A (growth arrest and DNA-damage-inducible, alpha), a regulator of DNA demethylation. GADD45A in turn recruits thymine-DNA glycosylase for base excision repair-mediated demethylation involving oxidation of 5-methylcytosine to 5-hydroxymethylcytosine in the TCF21 promoter by ten-eleven translocation methylcytosine dioxygenase proteins. The results reveal a function of lncRNAs, serving as a genomic address label for GADD45A-mediated demethylation of specific target genes.
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•TARID, a TCF21 antisense lncRNA, is downregulated in cancer cells•TARID binds to the TCF21 promoter and mediates transcriptional activation•TARID recruits GADD45A/TDG, thus promoting base excision-mediated demethylation•A lncRNA can serve as an address label for DNA demethylation
The function of most long noncoding RNAs (lncRNAs) is unknown. Arab et al. characterize TARID, a lncRNA that is antisense to the tumor suppressor TCF21, and find that it specifically directs demethylation and activation of TCF21 via GADD45A.
A total of 308,036 women were selected from the European Prospective Investigation into Cancer and Nutrition (EPIC) study to evaluate the association between tobacco smoking and the risk of cervical ...intraepithelial neoplasia of grade 3 (CIN3)/carcinoma in situ (CIS) and invasive cervical cancer (ICC). At baseline, participants completed a questionnaire and provided blood samples. During a mean follow‐up time of 9 years, 261 ICC cases and 804 CIN3/CIS cases were reported. In a nested case–control study, the baseline sera from 609 cases and 1,218 matched controls were tested for L1 antibodies against HPV types 11, 16, 18, 31, 33, 35, 45, 52, 58, and antibodies against Chlamydia trachomatis (CT), and Human Herpes Virus 2 (HHV‐2). Cervical samples were not available for HPV‐DNA analysis in this study. Multivariate analyses were used to estimate associations between smoking and risk of CIN3/CIS and ICC in the cohort and the case–control studies. In the cohort analyses smoking status, duration and intensity showed a two‐fold increased risk of CIN3/CIS and ICC, while time since quitting was associated with a two‐fold reduced risk. In the nested case–control study, consistent associations were observed after adjustment for HPV, CT and HHV‐2 serostatus, in both HPV seronegative and seropositive women. Results from this large prospective study confirm the role of tobacco smoking as an important risk factor for both CIN3/CIS and ICC, even after taking into account HPV exposure as determined by HPV serology. The strong beneficial effect of quitting smoking is an important finding that will further support public health policies for smoking cessation.
What's new?
Tobacco smoking is a cited cause of cervical cancer, but whether it causes cervical malignancy independent of human papillomavirus (HPV) infection is unclear. Here, strong associations were found between most measures of tobacco smoking and the risk of cervical intraepithelial neoplasia of grade 3/carcinoma in situ and invasive cervical cancer, after taking into account past exposure to HPV infection. Quitting smoking was associated with a 2‐fold risk reduction. The findings confirm the role of tobacco smoking in cervical carcinogenesis and show that quitting the habit has important benefits for cancer protection.
Prospective studies have indicated that elevated blood glucose levels may be linked with increased cancer risk, but the strength of the association is unclear. We examined the association between ...blood glucose and cancer risk in a prospective study of six European cohorts.
The Metabolic syndrome and Cancer project (Me-Can) includes cohorts from Norway, Austria, and Sweden; the current study included 274,126 men and 275,818 women. Mean age at baseline was 44.8 years and mean follow-up time was 10.4 years. Excluding the first year of follow-up, 18,621 men and 11,664 women were diagnosed with cancer, and 6,973 men and 3,088 women died of cancer. We used Cox regression models to calculate relative risk (RR) for glucose levels, and included adjustment for body mass index (BMI) and smoking status in the analyses. RRs were corrected for regression dilution ratio of glucose. RR (95% confidence interval) per 1 mmol/l increment of glucose for overall incident cancer was 1.05 (1.01-1.10) in men and 1.11 (1.05-1.16) in women, and corresponding RRs for fatal cancer were 1.15 (1.07-1.22) and 1.21 (1.11-1.33), respectively. Significant increases in risk among men were found for incident and fatal cancer of the liver, gallbladder, and respiratory tract, for incident thyroid cancer and multiple myeloma, and for fatal rectal cancer. In women, significant associations were found for incident and fatal cancer of the pancreas, for incident urinary bladder cancer, and for fatal cancer of the uterine corpus, cervix uteri, and stomach.
Data from our study indicate that abnormal glucose metabolism, independent of BMI, is associated with an increased risk of cancer overall and at several cancer sites. Our data showed stronger associations among women than among men, and for fatal cancer compared to incident cancer. Please see later in the article for the Editors' Summary.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
OBJECTIVE:--To investigate whether hyperglycemia is associated with increased cancer risk. RESEARCH DESIGN AND METHODS--In the Västerbotten Intervention Project of northern Sweden, fasting and ...postload plasma glucose concentrations were available for 33,293 women and 31,304 men and 2,478 incident cases of cancer were identified. Relative risk (RR) of cancer for levels of fasting and postload glucose was calculated with the use of Poisson models, with adjustment for age, year of recruitment, fasting time, and smoking status. Repeated measurements 10 years after baseline in almost 10,000 subjects were used to correct RRs for random error in glucose measurements. RESULTS:--Total cancer risk in women increased with rising plasma levels of fasting and postload glucose, up to an RR for the top versus bottom quartile of 1.26 (95% CI 1.09-1.47) (Ptrend <0.001) and 1.31 (1.12-1.52) (Ptrend = 0.001), respectively. Correction for random error in glucose measurements increased these risks up to 1.75 (1.32-2.36) and 1.63 (1.26-2.18), respectively. For men, corresponding uncorrected RR was 1.08 (0.92-1.27) (Ptrend = 0.25) and 0.98 (0.83-1.16) (Ptrend = 0.99), respectively. Risk of cancer of the pancreas, endometrium, urinary tract, and of malignant melanoma was statistically significantly associated with high fasting glucose with RRs of 2.49 (1.23-5.45) (Ptrend = 0.006), 1.86 (1.09-3.31) (Ptrend = 0.02), 1.69 (0.95-3.16) (Ptrend = 0.049), and 2.16 (1.14-4.35) (Ptrend = 0.01), respectively. Adjustment for BMI had no material effect on risk estimates. CONCLUSIONS:--The association of hyperglycemia with total cancer risk in women and in women and men combined for several cancer sites, independently of obesity, provides further evidence for an association between abnormal glucose metabolism and cancer.
Initial studies have indicated diabetes and obesity to be risk factors for hepatocellular carcinoma; but the association between other metabolic risk factors and primary liver cancer (PLC) has not ...been investigated. The metabolic syndrome and cancer project (Me‐Can) includes cohorts from Norway, Austria and Sweden with data on 578,700 subjects. We used Cox proportional hazard models to calculate relative risks (RRs) of PLC by body mass index (BMI), blood pressure and plasma levels of glucose, cholesterol and triglycerides as continuous standardized variables (z‐score with mean = 0 and standard deviation (SD) = 1) and their standardized sum of metabolic syndrome (MetS) z‐score. RRs were corrected for random error in measurements. During an average follow‐up of 12.0 years (SD = 7.8), 266 PLCs were diagnosed among cohort members. RR of liver cancer per unit increment of z‐score adjusted for age, smoking status and BMI and stratified by birth year, sex and sub‐cohorts, was for BMI 1.39 (95% confidence interval (CI) 1.24–1.58), mid blood pressure 2.08 (0.95–4.73), blood glucose 2.13 (1.55–2.94) cholesterol 0.62 (0.51–0.76) and serum triglycerides 0.85 (0.65–1.10). The RR per one unit increment of the MetS z‐score was 1.35 (1.12–1.61). BMI, glucose and a composite MetS score were positively and cholesterol negatively associated with risk of liver cancer.
A "Western" lifestyle characterized by physical inactivity and excess weight is associated with a number of metabolic and hormonal dysregulations, including increased circulating estrogen levels, ...hyperinsulinemia, hyperglycemia, and chronic inflammation. The same hormonal and metabolic axes might mediate the association between this lifestyle and the development of endometrial cancer. Using data collected within the European Prospective Investigation into Cancer and Nutrition (EPIC), a prospective cohort study carried out in 10 European countries during 1992-2000, we conducted a factor analysis to delineate important components that summarize the variation explained by a set of biomarkers and to examine their association with endometrial cancer risk. Prediagnostic levels of testosterone, androstenedione, dehydroepiandrosterone sulfate, sex hormone-binding globulin, estrone, estradiol, C-peptide, insulin-like growth factor-binding proteins 1 and 2, adiponectin, high- and low-density lipoprotein cholesterol, glucose, triglycerides, tumor necrosis factor (TNF) α, soluble TNF receptors 1 and 2, C-reactive protein, interleukin-6, and interleukin-1 receptor antagonist were measured in 233 incident endometrial cancer cases and 446 matched controls. Factor analysis identified 3 components associated with postmenopausal endometrial cancer risk that could be labeled "insulin resistance/metabolic syndrome," "steroids," and "inflammation" factors. A fourth component, "lipids," was not significantly associated with endometrial cancer. In conclusion, besides the well-known associations of risk with sex hormones and insulin-regulated physiological axes, our data further support the hypothesis that inflammation factors play a role in endometrial carcinogenesis.
Increased levels of thyroglobulin (Tg) and thyroid-stimulating hormone (TSH) are associated with differentiated thyroid carcinoma (TC) risk, but strong epidemiological evidence is lacking.
Three ...hundred fifty-seven incident TC case patients (n = 300 women and 57 men; mean age at blood collection = 51.5 years) were identified in the EPIC cohort study and matched with 2 (women) or 3 (men) control subjects using incidence density sampling. Matching included study center, sex, age, date, time, and fasting status at blood collection. Levels of total and free (f) thyroxine (T4) and triiodo-thyronine (T3), TSH, Tg, and anti-Tg antibodies (TgAb) were measured by commercially available immunoassays. Odds ratios (ORs) and 95% confidence intervals (CIs) were computed using conditional logistic regression. All statistical tests were two-sided.
TC risk was positively associated with Tg (OR for the highest vs lowest quartile = 9.15; 95% CI = 5.28 to 15.90; P < .001) and negatively associated with TSH level (OR = 0.56; 95% CI = 0.38 to 0.81; P = .001). Odds ratios were not modified by adjustment for weight and height and were consistent across sexes, age groups, and countries. The association with Tg was stronger in follicular than papillary TC. The odds ratio for TgAb-positivity was 1.50 (95% CI = 1.05 to 2.15; P = .03). Among case patients, TSH level was stable over time, whereas Tg level was higher in proximity to TC diagnosis. Areas under the receiver operating characteristic curve were 57% and 74% for TSH and Tg level, respectively.
High Tg levels precede by up to 8 years the detection of TC, pointing to a long sojourn time of the disease. Low TSH levels may predispose to TC onset. Neither marker has sufficient accuracy to be a screening test.
Few studies have assessed the metabolic syndrome (MetS) as an entity in relation to breast cancer risk, and results have been inconsistent. We aimed to examine the association between MetS factors ...(individually and combined) and risk of breast cancer incidence and mortality.
Two hundred ninety thousand women from Austria, Norway, and Sweden were enrolled during 1974-2005, with measurements of height, weight, blood pressure, and levels of glucose, cholesterol, and triglycerides. Relative risks (RR) of breast cancer were estimated using Cox proportional hazards regression for each MetS factor in quintiles and for standardized levels (z-scores) and for a composite z-score for the MetS.
There were 4,862 incident cases of breast cancer and 633 deaths from breast cancer identified. In women below age 50, there was a decreased risk of incident cancer for the MetS (per 1-unit increment of z-score; RR, 0.83; 95% confidence interval, 0.76-0.90) as well as for the individual factors (except for glucose). The lowest risks were seen among the heaviest women. In women above age 60, there was an increased risk of breast cancer mortality for the MetS (RR, 1.23; 95% confidence interval, 1.04-1.45) and for blood pressure and glucose. The strongest association with mortality was seen for increased glucose concentrations.
The MetS was associated with a decreased risk of incident breast cancer in women below age 50 with high body mass index, and with an increased risk of breast cancer mortality in women above 60.
Lifestyle interventions as recommended for cardiovascular disease prevention may be of value to prevent breast cancer mortality in postmenopausal women.
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