Alan A. Arslan

Genome-wide association study identifies variants in the ABO locus associated with susceptibility to pancreatic cancer

We conducted a two-stage genome-wide association study of pancreatic cancer, a cancer with one of the lowest survival rates worldwide. We genotyped 558,542 SNPs in 1,896 individuals with pancreatic cancer and 1,939 controls drawn from 12 prospective cohorts plus one hospital-based case-control study. We conducted a combined analysis of these groups plus an additional 2,457 affected individuals and 2,654 controls from eight case-control studies, adjusting for study, sex, ancestry and five principal components. We identified an association between a locus on 9q34 and pancreatic cancer marked by the SNP rs505922 (combined P = 5.37 × 10−8; multiplicative per-allele odds ratio 1.20; 95% confidence interval 1.12–1.28). This SNP maps to the first intron of the ABO blood group gene. Our results are consistent with earlier epidemiologic evidence suggesting that people with blood group O may have a lower risk of pancreatic cancer than those with groups A or B.

Circulating sex hormones and breast cancer risk factors in postmenopausal women: reanalysis of 13 studies.

Background:Breast cancer risk for postmenopausal women is positively associated with circulating concentrations of oestrogens and androgens, but the determinants of these hormones are not well understood.Methods:Cross-sectional analyses of breast cancer risk factors and circulating hormone concentrations in more than 6000 postmenopausal women controls in 13 prospective studies.Results:Concentrations of all hormones were lower in older than younger women, with the largest difference for dehydroepiandrosterone sulphate (DHEAS), whereas sex hormone-binding globulin (SHBG) was higher in the older women. Androgens were lower in women with bilateral ovariectomy than in naturally postmenopausal women, with the largest difference for free testosterone. All hormones were higher in obese than lean women, with the largest difference for free oestradiol, whereas SHBG was lower in obese women. Smokers of 15+ cigarettes per day had higher levels of all hormones than non-smokers, with the largest difference for testosterone. Drinkers of 20+ g alcohol per day had higher levels of all hormones, but lower SHBG, than non-drinkers, with the largest difference for DHEAS. Hormone concentrations were not strongly related to age at menarche, parity, age at first full-term pregnancy or family history of breast cancer.Conclusion:Sex hormone concentrations were strongly associated with several established or suspected risk factors for breast cancer, and may mediate the effects of these factors on breast cancer risk.

Anthropometric Measures, Body Mass Index and Pancreatic Cancer: a Pooled Analysis from the Pancreatic Cancer Cohort Consortium (PanScan)

BACKGROUND Obesity has been proposed as a risk factor for pancreatic cancer. METHODS Pooled data were analyzed from the National Cancer Institute Pancreatic Cancer Cohort Consortium (PanScan) to study the association between prediagnostic anthropometric measures and risk of pancreatic cancer. PanScan applied a nested case-control study design and included 2170 cases and 2209 control subjects. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using unconditional logistic regression for cohort-specific quartiles of body mass index (BMI [calculated as weight in kilograms divided by height in meters squared]), weight, height, waist circumference, and waist to hip ratio as well as conventional BMI categories (underweight, <18.5; normal weight, 18.5-24.9; overweight, 25.0-29.9; obese, 30.0-34.9; and severely obese, > or = 35.0). Models were adjusted for potential confounders. RESULTS In all of the participants, a positive association between increasing BMI and risk of pancreatic cancer was observed (adjusted OR for the highest vs lowest BMI quartile, 1.33; 95% CI, 1.12-1.58; P(trend) < .001). In men, the adjusted OR for pancreatic cancer for the highest vs lowest quartile of BMI was 1.33 (95% CI, 1.04-1.69; P(trend) < .03), and in women it was 1.34 (95% CI, 1.05-1.70; P(trend) = .01). Increased waist to hip ratio was associated with increased risk of pancreatic cancer in women (adjusted OR for the highest vs lowest quartile, 1.87; 95% CI, 1.31-2.69; P(trend) = .003) but less so in men. CONCLUSIONS These findings provide strong support for a positive association between BMI and pancreatic cancer risk. In addition, centralized fat distribution may increase pancreatic cancer risk, especially in women.

Circulating 25-Hydroxyvitamin D and Risk of Pancreatic Cancer Cohort Consortium Vitamin D Pooling Project of Rarer Cancers

Results from epidemiologic studies examining pancreatic cancer risk and vitamin D intake or 25-hydroxyvitamin D (25(OH)D) concentrations (the best indicator of vitamin D derived from diet and sun) have been inconsistent. Therefore, the authors conducted a pooled nested case-control study of participants from 8 cohorts within the Cohort Consortium Vitamin D Pooling Project of Rarer Cancers (VDPP) (1974–2006) to evaluate whether prediagnostic circulating 25(OH)D concentrations were associated with the development of pancreatic cancer. In total, 952 incident pancreatic adenocarcinoma cases occurred among participants (median follow-up, 6.5 years). Controls (n = 1,333) were matched to each case by cohort, age, sex, race/ethnicity, date of blood draw, and follow-up time. Conditional logistic regression analysis was used to calculate smoking-, body mass index-, and diabetes-adjusted odds ratios and 95% confidence intervals for pancreatic cancer. Clinically relevant 25(OH)D cutpoints were compared with a referent category of 50–<75 nmol/L. No significant associations were observed for participants with lower 25(OH)D status. However, a high 25(OH)D concentration (≥100 nmol/L) was associated with a statistically significant 2-fold increase in pancreatic cancer risk overall (odds ratio = 2.12, 95% confidence interval: 1.23, 3.64). Given this result, recommendations to increase vitamin D concentrations in healthy persons for the prevention of cancer should be carefully considered.

Cigarette Smoking and Pancreatic Cancer: A Pooled Analysis From the Pancreatic Cancer Cohort Consortium

Smoking is an established risk factor for pancreatic cancer; however, detailed examination of the association of smoking intensity, smoking duration, and cumulative smoking dose with pancreatic cancer is limited. The authors analyzed pooled data from the international Pancreatic Cancer Cohort Consortium nested case-control study (1,481 cases, 1,539 controls). Odds ratios and 95% confidence intervals were calculated by using unconditional logistic regression. Smoking intensity effects were examined with an excess odds ratio model that was linear in pack-years and exponential in cigarettes smoked per day and its square. When compared with never smokers, current smokers had a significantly elevated risk (odds ratio (OR) = 1.77, 95% confidence interval (CI): 1.38, 2.26). Risk increased significantly with greater intensity (> or =30 cigarettes/day: OR = 1.75, 95% CI: 1.27, 2.42), duration (> or =50 years: OR = 2.13, 95% CI: 1.25, 3.62), and cumulative smoking dose (> or =40 pack-years: OR = 1.78, 95% CI: 1.35, 2.34). Risk more than 15 years after smoking cessation was similar to that for never smokers. Estimates of excess odds ratio per pack-year declined with increasing intensity, suggesting greater risk for total exposure delivered at lower intensity for longer duration than for higher intensity for shorter duration. This finding and the decline in risk after smoking cessation suggest that smoking has a late-stage effect on pancreatic carcinogenesis.

Circulating levels of sex steroid hormones and risk of endometrial cancer in postmenopausal women

Experimental and epidemiological data support a role for sex steroid hormones in the pathogenesis of endometrial cancer. The associations of pre‐diagnostic blood concentrations of estradiol, estrone, testosterone, androstenedione, DHEAS and SHBG with endometrial cancer risk were investigated. A case‐control study was nested within 3 cohorts in New York (USA), Umeå (Sweden) and Milan (Italy). Cases were 124 postmenopausal women with invasive endometrial cancer. For each case, 2 controls were selected, matching the case on cohort, age and date of recruitment. Only postmenopausal women who did not use exogenous hormones at the time of blood donation were included. Odds ratios (OR) and their 95% confidence intervals (CI) were estimated by conditional logistic regression. ORs (95% CI) for endometrial cancer for quartiles with the highest hormone levels, relative to the lowest were as follows: 4.13 (1.76–9.72), ptrend = 0.0008 for estradiol, 3.67 (1.71–7.88), ptrend = 0.0007 for estrone, 2.15 (1.05–4.40), ptrend = 0.04 for androstenedione, 1.74 (0.88–3.46), ptrend = 0.06 for testosterone, 2.90 (1.42–5.90), ptrend = 0.002 for DHEAS and 0.46 (0.20–1.05), ptrend = 0.01 for SHBG after adjustment for body mass index, use of oral contraceptives and hormone replacement therapy. The results of our multicenter prospective study showed a strong direct association of circulating estrogens, androgens and an inverse association of SHBG levels with endometrial cancer in postmenopausal women. The effect of elevated androstenedione and testosterone levels on disease risk seems to be mediated mainly through their conversion to estrogens, although an independent effect of androgens on tumor growth cannot be ruled out, in particular in the years close to diagnosis.

Prediagnostic levels of C-peptide, IGF-I, IGFBP -1, -2 and -3 and risk of endometrial cancer†

Conditions related to chronic hyperinsulinemia, such as obesity, noninsulin dependent diabetes mellitus and polycystic ovary syndrome, are associated with an increased risk of endometrial cancer. Elevated plasma IGF‐I and decreased levels of IGF‐binding proteins have been shown to be associated with increased risk of several cancer types that are frequent in affluent societies. We investigated for the first time in a prospective study the association of pre‐diagnostic blood concentrations of C‐peptide (a marker of pancreatic insulin production), IGF‐I, IGFBP‐1, ‐2 and ‐3 with endometrial cancer risk. A case‐control study was nested within 3 cohorts in New York (USA), Umeå (Sweden) and Milan (Italy). It included 166 women with primary invasive endometrial cancer and 315 matched controls, of which 44 case and 78 control subjects were premenopausal at recruitment. Endometrial cancer risk increased with increasing levels of C‐peptide (ptrend = 0.0002), up to an odds ratio (OR) of 4.76 [95% confidence interval (CI) = 1.91–11.8] for the highest quintile. This association remained after adjustment for BMI and other confounders [OR for the top quintile = 4.40 (1.65–11.7)]. IGFBP‐1 levels were inversely related to endometrial cancer [ptrend = 0.002; OR in the upper quintile = 0.30 (0.15–0.62)], but the association was weakened and lost statistical significance after adjustment for confounders [ptrend = 0.06; OR in the upper quintile = 0.49 (0.22–1.07)]. Risk was unrelated to levels of IGF‐I, IGFBP‐2 and IGFBP‐3. Chronic hyperinsulinemia, as reflected by increased circulating C‐peptide, is associated with increased endometrial cancer risk. Decrease in the prevalence of chronic hyperinsulinemia, through changes in lifestyle or medication, is expected to prevent endometrial cancer.

The diagnosis, treatment, and follow-up of cesarean scar pregnancy.

OBJECTIVE The diagnosis and treatment of cesarean scar pregnancy (CSP) is challenging. The objective of this study was to evaluate the diagnostic method, treatments, and long-term follow-up of CSP. STUDY DESIGN This is a retrospective case series of 26 patients between 6-14 postmenstrual weeks suspected to have CSP who were referred for diagnosis and treatment. The diagnosis was confirmed with transvaginal ultrasound. In 19 of the 26 patients the gestational sac was injected with 50 mg of methotrexate: 25 mg into the area of the embryo/fetus and 25 mg into the placental area; and an additional 25 mg was administered intramuscularly. Serial serum human chorionic gonadotropin determinations were obtained. Gestational sac volumes and vascularization were assessed by 3-dimensional ultrasound and used to monitor resolution of the injected site and outcome. RESULTS The 19 treated pregnancies were followed for 24-177 days. No complications were observed. After the treatment, typically, there was an initial increase in the human chorionic gonadotropin serum concentrations as well as in the volume of the gestational sac and their vascularization. After a variable time period mentioned elsewhere the values decreased, as expected. CONCLUSION Combined intramuscular and intragestational methotrexate injection treatment was successful in treating these CSP.

Pancreatic Cancer Risk and ABO Blood Group Alleles: Results from the Pancreatic Cancer Cohort Consortium

A recent genome-wide association study (PanScan) identified significant associations at the ABO gene locus with risk of pancreatic cancer, but the influence of specific ABO genotypes remains unknown. We determined ABO genotypes (OO, AO, AA, AB, BO, and BB) in 1,534 cases and 1,583 controls from 12 prospective cohorts in PanScan, grouping participants by genotype-derived serologic blood type (O, A, AB, and B). Adjusted odds ratios (ORs) for pancreatic cancer by ABO alleles were calculated using logistic regression. Compared with blood type O, the ORs for pancreatic cancer in subjects with types A, AB, and B were 1.38 [95% confidence interval (95% CI), 1.18-1.62], 1.47 (95% CI, 1.07-2.02), and 1.53 (95% CI, 1.21-1.92), respectively. The incidence rates for blood types O, A, AB, and B were 28.9, 39.9, 41.8, and 44.5 cases per 100,000 subjects per year. An increase in risk was noted with the addition of each non-O allele. Compared with OO genotype, subjects with AO and AA genotype had ORs of 1.33 (95% CI, 1.13-1.58) and 1.61 (95% CI, 1.22-2.18), whereas subjects with BO and BB genotypes had ORs of 1.45 (95% CI, 1.14-1.85) and 2.42 (1.28-4.57). The population attributable fraction for non-O blood type was 19.5%. In a joint model with smoking, current smokers with non-O blood type had an adjusted OR of 2.68 (95% CI, 2.03-3.54) compared with nonsmokers of blood type O. We concluded that ABO genotypes were significantly associated with pancreatic cancer risk.A recent genome-wide association study (PanScan) identified significant associations at the ABO gene locus with pancreatic cancer risk; however, the mechanisms underlying these associations and the influence of specific ABO genotypes remain unknown. We determined ABO genotypes (OO, AO, AA, AB, BO, BB) in 1534 cases and 1583 controls from 12 prospective cohort studies participating in PanScan. We also grouped participants by genotype-derived serologic blood type (O, A, AB, B). Adjusted odds ratios (ORs) for pancreatic cancer by ABO alleles were calculated using logistic regression. Compared to blood type O, the ORs for pancreatic cancer in subjects with types A, AB, and B were 1.38 (95% confidence interval [CI], 1.18-1.62), 1.47 (95% CI, 1.07-2.02), and 1.53 (95% CI, 1.21-1.92), respectively. The incidence rates (cases per 100,000 subjects per year) for blood types O, A, AB, and B were 28.9, 39.9, 41.8, and 44.5. An increase in risk was noted with the addition of each non-O allele. Compared to OO, subjects with AO and AA had ORs of 1.33 (95% CI, 1.13-1.58) and 1.61 (95% CI, 1.22-2.18), while subjects with BO and BB had ORs of 1.45 (95% CI, 1.14-1.85) and 2.42 (1.28-4.57). The population attributable fraction for non-O blood type was 19.5%. In a joint model with smoking, current smokers with non-O blood type had an adjusted OR of 2.68 (95% CI, 2.03-3.54), compared with non-smokers with blood type O. Among participants in a large prospective cohort consortium, ABO genotypes were significantly associated with pancreatic cancer risk.

Height, Body Mass Index, and Ovarian Cancer: A Pooled Analysis of 12 Cohort Studies

Background: Although many studies have investigated the association between anthropometry and ovarian cancer risk, results have been inconsistent. Methods: The associations of height, body mass index (BMI), and ovarian cancer risk were examined in a pooled analysis of primary data from 12 prospective cohort studies from North America and Europe. The study population consisted of 531,583 women among whom 2,036 epithelial ovarian cancer cases were identified. To summarize associations, study-specific relative risks (RR) were estimated using the Cox proportional hazards model and then combined using a random-effects model. Results: Women with height ≥1.70 m had a pooled multivariate RR of 1.38 [95% confidence interval (95% CI), 1.16-1.65] compared with those with height <1.60 m. For the same comparison, multivariate RRs were 1.79 (95% CI, 1.07-3.00) for premenopausal and 1.25 (95% CI, 1.04-1.49) for postmenopausal ovarian cancer (Pinteraction = 0.14). The multivariate RR for women with a BMI ≥30 kg/m2 was 1.03 (95% CI, 0.86-1.22) compared with women with a BMI from 18.5 to 23 kg/m2. For the same comparison, multivariate RRs were 1.72 (95% CI, 1.02-2.89) for premenopausal and 1.07 (95% CI, 0.87-1.33) for postmenopausal women (Pinteraction = 0.07). There was no statistically significant heterogeneity between studies with respect to height or BMI. BMI in early adulthood was not associated with ovarian cancer risk. Conclusion: Height was associated with an increased ovarian cancer risk, especially in premenopausal women. BMI was not associated with ovarian cancer risk in postmenopausal women but was positively associated with risk in premenopausal women. (Cancer Epidemiol Biomarkers Prev 2008;17(4):902–12)