Faculty Bibliography

Background: Since 1980, liver cancer has been among the most rapidly increasing cancer types in the United States (US), with 5-year survival rates of approximately 17%. While tobacco and alcohol are known to be associated with primary liver cancer, it is unclear whether they only increase the risk of hepatocellular carcinoma (HCC), the most common type of liver cancer, or whether they also increase risk of intrahepatic cholangiocarcinoma (ICC), second most common histologic type. Additionally, it is unclear what amount of alcohol consumption is associated with an increased risk of liver cancer. As liver cancer is a rare cancer type, we conducted a study of pooled data from the National Cancer Institute Cohort Consortium to examine the associations between smoking and alcohol use and liver cancer, stratified by histologic subtype. Methods: In the Liver Cancer Pooling Project, a consortium of US-based cohort studies, we pooled data from 1,518,741 individuals (HCC n=1,423, ICC n=410) in 14 cohorts. Multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CI) were estimated using proportional hazards regression. Cubic splines were used to model the association between alcohol and liver cancer risk. Results: Compared to never smokers, both former and current smokers at study baseline had an increased risk of ICC (HR=1.32, 95% CI: 1.03-1.68 and HR=1.47, 95% CI: 1.07-2.02, respectively) and HCC (HR=1.24, 95% CI: 1.08-1.43 and HR=1.86, 95% CI: 1.57-2.20, respectively). This finding was consistent for heavier smoking intensity, longer duration of smoking, and more pack-years of smoking. Heavy alcohol consumption was associated with an 87% increased risk of HCC (HR>=7 drinks/day v. non-drinker=1.87, 95% CI: 1.41-2.47) and a non-significant 68% increased risk of ICC (HR>=5 drinks/day v. non-drinker=1.68, 95% CI: 0.99-2.86). Risk of HCC significantly increased at 4.5 alcoholic drinks per day, while risk of ICC was non-significantly increased with any amount of consumption. Conclusions: These findings suggest that, in a US population, cigarette smoking is associated with an increased risk of both histologic subtypes of primary liver cancer - HCC and ICC. In contrast, alcohol consumption was primarily associated with an increased risk of HCC. These results suggest that smoking cessation and alcohol reduction programs could be important intervention opportunities for these lethal cancer types

Body fatness is an established risk factor for postmenopausal breast cancer, but it is unknown if this risk associated with excess body weight is reversible. We conducted a pooled analysis of 11 prospective studies in the Pooling Project of Prospective Studies of Diet and Cancer. Each study had adult body weight data at three time points, as well as follow-up for subsequent risk of breast cancer after the third weight measure. Weight change was assessed using reported or measured weight at baseline and two follow-up time points, each generally four to six years apart (over a total of ~10 years). Stable weight for each interval was defined as weight within 2kg of the previous weight. The referent group was women with stable weight (within 2kg) at all three time points across the 10-year period. Among 340,055 women, 10,427 breast cancers were diagnosed during follow-up. Multivariable hazard ratios (HR) and 95% confidence intervals (CI) controlling for baseline body mass index (BMI), baseline physical activity, and postmenopausal hormone (PMH) use at the start of breast cancer follow-up, were estimated using proportional hazards regression on an aggregated dataset from all studies. Women who lost weight and kept the weight off, were at a lower risk of breast cancer than women with stable weight over the 10 years: >2.-4.5kg lost between baseline and the first follow-up body weight measure (n=482 cases): HR=0.92, 95% CI: 0.83-1.03; >4.5-9kg lost (n=283 cases): HR=0.86, 95% CI: 0.76-0.98; >9kg lost (n=95 cases): HR =0.81, 95%CI: 0.65-1.00). Women who initially lost weight (>2kg), but then re-gained it had a similar risk of breast cancer to those with stable weight over the same time period. When results were stratified by baseline age and BMI, there was no association between sustained weight loss and breast cancer among women younger than 50 years, nor those with a normal BMI (18.5-25 kg/m²) before weight loss. Among women who were aged 50 or more years and overweight or obese before the weight loss period, we observed a 21% lower risk of breast cancer for sustained weight loss of >=4.5kg compared to women with stable weight over the same time period (n=245 cases, HR=0.79, 95% CI: 0.68-0.93). This observed association was driven by women who were not taking PMH (n=156, HR=0.71, 95% CI: 0.58-0.86). In this large, pooled prospective analysis of weight loss and breast cancer risk we found that losing 4.5 kg- and keeping it off-may lower breast cancer risk, particularly for women older than 50 who are overweight or obese. The results may provide motivation for women with elevated BMI to lose weight and potentially reduce their risk of breast cancer

BACKGROUND: The Mullerian ducts are the embryological precursors of the female reproductive tract, including the uterus; anti-Mullerian hormone (AMH) has a key role in the regulation of foetal sexual differentiation. Anti-Mullerian hormone inhibits endometrial tumour growth in experimental models by stimulating apoptosis and cell cycle arrest. To date, there are no prospective epidemiologic data on circulating AMH and endometrial cancer risk. METHODS: We investigated this association among women premenopausal at blood collection in a multicohort study including participants from eight studies located in the United States, Europe, and China. We identified 329 endometrial cancer cases and 339 matched controls. Anti-Mullerian hormone concentrations in blood were quantified using an enzyme-linked immunosorbent assay. Conditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CI) across tertiles and for a doubling of AMH concentrations (ORlog2). Subgroup analyses were performed by ages at blood donation and diagnosis, oral contraceptive use, and tumour characteristics. RESULTS: Anti-Mullerian hormone was not associated with the risk of endometrial cancer overall (ORlog2: 1.07 (0.99-1.17)), or with any of the examined subgroups. CONCLUSIONS: Although experimental models implicate AMH in endometrial cancer growth inhibition, our findings do not support a role for circulating AMH in the aetiology of endometrial cancer.British Journal of Cancer advance online publication 5 September 2017; doi:10.1038/bjc.2017.299 www.bjcancer.com.

BACKGROUND: Pregnancy and parity are associated with subsequent breast cancer risk. Experimental and epidemiologic data suggest a role for pregnancy sex steroid hormones. METHODS: We conducted a nested case-control study in the Northern Sweden Maternity Cohort (1975-2007). Eligible women had provided a blood sample in the first 20 weeks of gestation during a primiparous pregnancy leading to a term delivery. The current study includes 223 cases and 417 matched controls (matching factors: age at and date of blood collection). Estrogen receptor (ER) and progesterone receptor (PR) status was available for all cases; androgen receptor (AR) data were available for 41% of cases (n = 92). Sex steroids were quantified by high-performance liquid chromatography tandem mass spectrometry. Odds ratios (ORs) and 95% confidence intervals were estimated using conditional logistic regression. RESULTS: Higher concentrations of circulating progesterone in early pregnancy were inversely associated with ER+/PR+ breast cancer risk (ORlog2: 0.64 (0.41-1.00)). Higher testosterone was positively associated with ER+/PR+ disease risk (ORlog2: 1.57 (1.13-2.18)). Early pregnancy estrogens were not associated with risk, except for relatively high estradiol in the context of low progesterone (split at median, relative to low concentrations of both; OR: 1.87 (1.11-3.16)). None of the investigated hormones were associated with ER-/PR- disease, or with AR+ or AR+/ER+/PR+ disease. CONCLUSIONS: Consistent with experimental models, high progesterone in early pregnancy was associated with lower risk of ER+/PR+ breast cancer in the mother. High circulating testosterone in early pregnancy, which likely reflects nonpregnant premenopausal exposure, was associated with higher risk of ER+/PR+ disease.

Breast cancer is a leading cancer diagnosis among premenopausal women around the world. Unlike rates in postmenopausal women, incidence rates of advanced breast cancer have increased in recent decades for premenopausal women. Progress in identifying contributors to breast cancer risk among premenopausal women has been constrained by the limited numbers of premenopausal breast cancer cases in individual studies and resulting low statistical power to subcategorize exposures or to study specific subtypes. The Premenopausal Breast Cancer Collaborative Group was established to facilitate cohort-based analyses of risk factors for premenopausal breast cancer by pooling individual-level data from studies participating in the United States National Cancer Institute Cohort Consortium. This paper describes the Group, including the rationale for its initial aims related to pregnancy, obesity, and physical activity. We also describe the 20 cohort studies with data submitted to the Group by June 2016. The infrastructure developed for this work can be leveraged to support additional investigations.

Background: Circulating concentrations of biomarkers that are related to vitamin status vary by factors such as diet, fortification, and supplement use. Published biomarker concentrations have also been influenced by the variation across laboratories, which complicates a comparison of results from different studies.Objective: We robustly and comprehensively assessed differences in biomarkers that are related to vitamin status across geographic regions.Design: The trial was a cross-sectional study in which we investigated 38 biomarkers that are related to vitamin status and one-carbon and tryptophan metabolism in serum and plasma from 5314 healthy control subjects representing 20 cohorts recruited from the United States, Nordic countries, Asia, and Australia, participating in the Lung Cancer Cohort Consortium. All samples were analyzed in a centralized laboratory.Results: Circulating concentrations of riboflavin, pyridoxal 5'-phosphate, folate, vitamin B-12, all-trans retinol, 25-hydroxyvitamin D, and alpha-tocopherol as well as combined vitamin scores that were based on these nutrients showed that the general B-vitamin concentration was highest in the United States and that the B vitamins and lipid soluble vitamins were low in Asians. Conversely, circulating concentrations of metabolites that are inversely related to B vitamins involved in the one-carbon and kynurenine pathways were high in Asians. The high B-vitamin concentration in the United States appears to be driven mainly by multivitamin-supplement users.Conclusions: The observed differences likely reflect the variation in intake of vitamins and, in particular, the widespread multivitamin-supplement use in the United States. The results provide valuable information about the differences in biomarker concentrations in populations across continents.

Invasive epithelial ovarian cancer (EOC) is the most lethal gynecologic malignancy. The etiology of EOC remains elusive; however, experimental and epidemiologic data suggest a role for hormone-related exposures in ovarian carcinogenesis and risk factor differences by histologic phenotypes and developmental pathways. Research on pre-diagnosis androgen concentrations and EOC risk has yielded inconclusive results, and analyses incorporating EOC subtypes are sparse. We conducted a pooled analysis of 7 nested case-control studies in the Ovarian Cancer Cohort Consortium to investigate the association between pre-diagnosis circulating androgens (testosterone, free testosterone, androstenedione, dehydroepiandrosterone sulfate (DHEAS)), sex hormone binding globulin (SHBG), and EOC risk by tumor characteristics (i.e. histology, grade, and stage). The final study population included 1,331 EOC cases and 3,017 matched controls. Multivariable conditional logistic regression was used to assess risk associations in pooled individual data. Testosterone was positively associated with EOC risk (all subtypes combined, Odds Ratio (OR)log2=1.12 [95% Confidence Interval (CI) 1.02-1.24]); other endogenous androgens and SHBG were not associated with overall risk. Higher concentrations of testosterone and androstenedione associated with an increased risk in endometrioid and mucinous tumors (e.g., testosterone, endometrioid tumors, ORlog2=1.40 [1.03-1.91]), but not serous or clear cell. An inverse association was observed between androstenedione and high grade serous tumors (ORlog2=0.76 [0.60-0.96]). Our analyses provide further evidence for a role of hormone-related pathways in EOC risk, with differences in associations between androgens and histologic subtypes of EOC.

OBJECTIVE: To identify reproductive, lifestyle, hormonal, and other correlates of circulating antimullerian hormone (AMH) concentrations in mostly late premenopausal women. DESIGN: Cross-sectional study. SETTING: Not applicable. PATIENT(S): A total of 671 premenopausal women not known to have cancer. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Concentrations of AMH were measured in a single laboratory using the picoAMH ELISA. Multivariable-adjusted median (and interquartile range) AMH concentrations were calculated using quantile regression for several potential correlates. RESULT(S): Older women had significantly lower AMH concentrations (>/=40 [n = 444] vs. <35 years [n = 64], multivariable-adjusted median 0.73 ng/mL vs. 2.52 ng/mL). Concentrations of AMH were also significantly lower among women with earlier age at menarche (<12 [n = 96] vs. >/=14 years [n = 200]: 0.90 ng/mL vs. 1.12 ng/mL) and among current users of oral contraceptives (n = 27) compared with never or former users (n = 468) (0.36 ng/mL vs. 1.15 ng/mL). Race, body mass index, education, height, smoking status, parity, and menstrual cycle phase were not significantly associated with AMH concentrations. There were no significant associations between AMH concentrations and androgen or sex hormone-binding globulin concentrations or with factors related to blood collection (e.g., sample type, time, season, and year of blood collection). CONCLUSION(S): Among premenopausal women, lower AMH concentrations are associated with older age, a younger age at menarche, and currently using oral contraceptives, suggesting these factors are related to a lower number or decreased secretory activity of ovarian follicles.

Background: There are few established risk factors for gallbladder cancer beyond gallstones. Recent studies suggest a higher risk with high body mass index (BMI), an indicator of general heaviness, but evidence from other body size measures is lacking.Methods: Associations of adult BMI, young adult BMI, height, adult weight gain, waist circumference (WC), waist-height ratio (WHtR), hip circumference (HC), and waist-hip ratio (WHR) with gallbladder cancer risk were evaluated. Individual-level data from 1,878,801 participants in 19 prospective cohort studies (14 studies had circumference measures) were harmonized and included in this analysis. Multivariable Cox proportional hazards regression estimated hazard ratios (HR) and 95% confidence intervals (CI).Results: After enrollment, 567 gallbladder cancer cases were identified during 20.1 million person-years of observation, including 361 cases with WC measures. Higher adult BMI (per 5 kg/m2, HR: 1.24; 95% CI, 1.13-1.35), young adult BMI (per 5 kg/m2, HR: 1.12; 95% CI, 1.00-1.26), adult weight gain (per 5 kg, HR: 1.07; 95% CI, 1.02-1.12), height (per 5 cm, HR: 1.10; 95% CI, 1.03-1.17), WC (per 5 cm, HR: 1.09; 95% CI, 1.02-1.17), WHtR (per 0.1 unit, HR: 1.24; 95% CI, 1.00-1.54), and HC (per 5 cm, HR: 1.13; 95% CI, 1.04-1.22), but not WHR (per 0.1 unit, HR: 1.03; 95% CI, 0.87-1.22), were associated with higher risks of gallbladder cancer, and results did not differ meaningfully by sex or other demographic/lifestyle factors.Conclusions: These findings indicate that measures of overall and central excess body weight are associated with higher gallbladder cancer risks.Impact: Excess body weight is an important, and potentially preventable, gallbladder cancer risk factor. Cancer Epidemiol Biomarkers Prev; 26(4); 1-10. (c)2017 AACR.

Epidemiological studies have reported inconsistent findings for the association between B vitamins and breast cancer (BC) risk. We investigated the relationship between biomarkers of folate and vitamin B12 and the risk of BC in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Plasma concentrations of folate and vitamin B12 were determined in 2,491 BC cases individually matched to 2,521 controls among women who provided baseline blood samples. Multivariable logistic regression models were used to estimate odds ratios by quartiles of either plasma B vitamin. Subgroup analyses by menopausal status, hormone receptor status of breast tumors (ER, PR, and HER2), alcohol intake, and MTHFR polymorphisms (677C>T and 1298A>C) were also performed. Plasma levels of folate and vitamin B12 were not significantly associated with the overall risk of BC or by hormone receptor status. A marginally positive association was found between vitamin B12 status and BC risk in women consuming above the median level of alcohol (ORQ4-Q1 = 1.26; 95% CI 1.00-1.58; Ptrend = 0.05). Vitamin B12 status was also positively associated with BC risk in women with plasma folate levels below the median value (ORQ4-Q1 = 1.29; 95% CI 1.02-1.62; Ptrend = 0.03). Overall, folate and vitamin B12 status was not clearly associated with BC risk in this prospective cohort study. However, potential interactions between vitamin B12 and alcohol or folate on the risk of BC deserve further investigation