Vidar G. Flote

Cyclic endogenous estrogen and progesterone vary by mammographic density phenotypes in premenopausal women.

Estrogen and progesterone are key factors in the development of breast cancer, but it remains unclear whether these hormones are associated with mammographic density phenotypes in premenopausal women. We measured percent mammographic density, nondense area, and absolute mammographic density using computer-assisted breast density readings (Madena) from digitized mammograms taken on a scheduled day of the menstrual cycle (day 7–12) among 202 healthy, premenopausal women (Energy Balance and Breast cancer Aspects Study-I). Daily salivary concentrations of 17&bgr;-estradiol and progesterone throughout an entire menstrual cycle and fasting morning serum concentrations of hormones on 3 specific days of the menstrual cycle were assessed. Salivary and serum 17&bgr;-estradiol and progesterone were positively associated with percent mammographic density, we observed by 1 SD increase in overall salivary estradiol (&bgr;-value equal to 2.07, P=0.044), luteal salivary progesterone (&bgr;-value equal to 2.40, P=0.020). Women with above-median percent mammographic density had a 20% higher mean salivary 17&bgr;-estradiol level throughout the menstrual cycle. The odds ratio for having above-median percent mammographic density (>28.5%) per 1 SD increase in overall salivary 17&bgr;-estradiol was 1.66 (95% confidence interval 1.13–2.45). Women in the top tertile of the overall average daily 17&bgr;-estradiol concentrations had an odds ratio of 2.54 (confidence interval 1.05–6.16) of above-median percent mammographic density compared with women in the bottom tertile. Our finding of a relationship between estrogen, progesterone, and percent mammographic density and not with other mammographic density phenotypes in premenopausal women is biologically plausible, but needs to be replicated in larger studies.

Alcohol consumption, endogenous estrogen and mammographic density among premenopausal women

IntroductionAlcohol consumption may promote aromatization of androgens to estrogens, which may partly explain the observations linking alcohol consumption to higher breast cancer risk. Whether alcohol consumption is associated with endogenous estrogen levels, and mammographic density phenotypes in premenopausal women remains unclear.MethodsAlcohol consumption was collected by self-report and interview, using semi quantitative food frequency questionnaires, and a food diary during seven days of a menstrual cycle among 202 premenopausal women, participating in the Energy Balance and Breast Cancer Aspects (EBBA) study I. Estrogen was assessed in serum and daily in saliva across an entire menstrual cycle. Computer-assisted mammographic density (Madena) was obtained from digitized mammograms taken between days 7–12 of the menstrual cycle. Multivariable regression models were used to investigate the associations between alcohol consumption, endogenous estrogen and mammographic density phenotypes.ResultsCurrent alcohol consumption was positively associated with endogenous estrogen, and absolute mammographic density. We observed 18 % higher mean salivary 17β-estradiol levels throughout the menstrual cycle, among women who consumed more than 10 g of alcohol per day compared to women who consumed less than 10 g of alcohol per day (p = 0.034). Long-term and past-year alcohol consumption was positively associated with mammographic density. We observed a positive association between alcohol consumption (past year) and absolute mammographic density; high alcohol consumers (≥7 drinks/week) had a mean absolute mammographic density of 46.17 cm2 (95 % confidence interval (CI) 39.39, 52.95), while low alcohol consumers (<1 drink/week) had a mean absolute mammographic density of 31.26 cm2 (95 % CI 25.89, 36.64) (p-trend 0.001). After adjustments, high consumers of alcohol (≥7 drinks/week), had 5.08 (95 % CI 1.82, 14.20) times higher odds of having absolute mammographic density above median (>32.4 cm2), compared to low (<1 drink/week) alcohol consumers.ConclusionAlcohol consumption was positively associated with daily endogenous estrogen levels and mammographic density in premenopausal women. These associations could point to an important area of breast cancer prevention.

Genetic Polymorphism CYP17 rs2486758 and Metabolic Risk Factors Predict Daily Salivary 17β-Estradiol Concentration in Healthy Premenopausal Norwegian Women. The EBBA-I Study

CONTEXT The relationship between low-penetrance genes, metabolic risk factors, and levels of endogenous 17β-estradiol and progesterone, which play a role in breast cancer risk, remains unclear. OBJECTIVE The aim of this study was to determine whether common polymorphisms in CYP17, in combination with metabolic risk factors (individually or clustered), alter salivary concentrations of free biologically active 17β-estradiol and progesterone among healthy premenopausal Norwegian women. DESIGN Eight single nucleotide polymorphisms in CYP17 were genotyped in 203 healthy premenopausal women aged 25-35 yr in the Norwegian EBBA-I Study, conducted in 2000-2002. Daily salivary concentrations of 17β-estradiol and progesterone were measured throughout one menstrual cycle. A clustered metabolic score was calculated, including waist circumference, mean arterial pressure, insulin resistance, fasting triglycerides, and total cholesterol/high-density lipoprotein cholesterol ratio. The study hypothesis was tested in multivariable linear regression and generalized estimating equation models. RESULTS Women in the upper tertile of clustered metabolic score with the CYP17 rs2486758 minor allele had daily salivary 17β-estradiol concentrations that were 53% higher than other study women throughout the menstrual cycle (P < 0.001). Similarly, women in the upper tertile of total cholesterol/high-density lipoprotein cholesterol ratio, fasting triglycerides, and insulin resistance had 44, 32, and 24% higher daily salivary 17β-estradiol concentrations, respectively (all P < 0.05). CONCLUSION The CYP17 rs2486758 minor allele may predispose to higher 17β-estradiol levels, particularly in premenopausal women with a high clustered metabolic score. Thus, modification of metabolic risk factors may have significant implications for the prevention of breast cancer in women with the minor allele of CYP17 rs2486758.

Ovarian hormones and reproductive risk factors for breast cancer in premenopausal women: the Norwegian EBBA-I study

BACKGROUND Ovarian hormones, parity and length of ‘menarche-to-first birth’ time interval are known risk factors for breast cancer, yet the associations between 17β-estradiol, progesterone and these reproductive factors remain unclear. METHODS A total of 204 women (25–35 years) who participated in the Norwegian EBBA-I study collected daily saliva samples for one complete menstrual cycle, and filled in a reproductive history questionnaire. Anthropometry was measured and saliva samples were analyzed for ovarian hormones. Associations between parity, the interval and ovarian hormones, and effects of hormone-related lifestyle factors were studied in linear regression models. RESULTS Mean age was 30.7 years, and age of menarche 13.1 years. Parous women had on average 1.9 births, and age at first birth was 24.5 years. No association was observed between parity and ovarian steroids. In nulliparous women, higher waist circumference (≥77.75 cm) and longer oral contraceptive (OC) use (≥3 years) were associated with higher levels of 17β-estradiol. Short (<10 years) versus long (>13.5 years) ‘menarche-to-first birth’ interval was associated with higher overall mean (Ptrend = 0.029), 47% higher maximum peak and 30% higher mid-cycle levels of 17β-estradiol. We observed a 2.6% decrease in overall mean salivary 17β-estradiol with each 1-year increase in the interval. CONCLUSIONS Nulliparous women may be more susceptible to lifestyle factors, abdominal overweight and past OC use, influencing metabolic and hormonal profiles and thus breast cancer risk. Short time between ‘menarche-to-first birth’ is linked to higher ovarian hormone levels among regularly cycling women, suggesting that timing of first birth is related to fecundity.

High-Density Lipoprotein-Cholesterol, Daily Estradiol and Progesterone, and Mammographic Density Phenotypes in Premenopausal Women

High-density lipoprotein-cholesterol (HDL-C) may influence the proliferation of breast tumor cells, but it is unclear whether low HDL-C levels, alone or in combination with cyclic estrogen and progesterone, are associated with mammographic density, a strong predictor of breast cancer development. Fasting morning serum concentrations of HDL-C were assessed in 202 premenopausal women, 25 to 35 years of age, participating in the Norwegian Energy Balance and Breast Cancer Aspects (EBBA) I study. Estrogen and progesterone were measured both in serum, and daily in saliva, throughout an entire menstrual cycle. Absolute and percent mammographic density was assessed by a computer-assisted method (Madena), from digitized mammograms (days 7–12). Multivariable models were used to study the associations between HDL-C, estrogen and progesterone, and mammographic density phenotypes. We observed a positive association between HDL-C and percent mammographic density after adjustments (P = 0.030). When combining HDL-C, estradiol, and progesterone, we observed among women with low HDL-C (<1.39 mmol/L), a linear association between salivary 17β-estradiol, progesterone, and percent and absolute mammographic density. Furthermore, in women with low HDL-C, each one SD increase of salivary mid-menstrual 17β-estradiol was associated with an OR of 4.12 (95% confidence intervals; CI, 1.30–13.0) of having above-median percent (28.5%), and an OR of 2.5 (95% CI, 1.13–5.50) of having above-median absolute mammographic density (32.4 cm2). On the basis of plausible biologic mechanisms linking HDL-C to breast cancer development, our findings suggest a role of HDL-C, alone or in combination with estrogen, in breast cancer development. However, our small hypothesis generating study requires confirmation in larger studies. Cancer Prev Res; 8(6); 535–44. ©2015 AACR.

Metabolite and lipoprotein responses and prediction of weight gain during breast cancer treatment

BackgroundBreast cancer treatment has metabolic side effects, potentially affecting risk of cardiovascular disease (CVD) and recurrence. We aimed to compare alterations in serum metabolites and lipoproteins during treatment between recipients and non-recipients of chemotherapy, and describe metabolite profiles associated with treatment-related weight gain.MethodsThis pilot study includes 60 stage I/II breast cancer patients who underwent surgery and were treated according to national guidelines. Serum sampled pre-surgery and after 6 and 12 months was analysed by MR spectroscopy and mass spectrometry. In all, 170 metabolites and 105 lipoprotein subfractions were quantified.ResultsThe metabolite and lipoprotein profiles of chemotherapy recipients and non-recipients changed significantly 6 months after surgery (p < 0.001). Kynurenine, the lipid signal at 1.55–1.60 ppm, ADMA, 2 phosphatidylcholines (PC aa C38:3, PC ae C42:1), alpha-aminoadipic acid, hexoses and sphingolipids were increased in chemotherapy recipients after 6 months. VLDL and small dense LDL increased after 6 months, while HDL decreased, with triglyceride enrichment in HDL and LDL. At baseline, weight gainers had less acylcarnitines, phosphatidylcholines, lyso-phosphatidylcholines and sphingolipids, and showed an inflammatory lipid profile.ConclusionChemotherapy recipients exhibit metabolic changes associated with inflammation, altered immune response and increased risk of CVD. Altered lipid metabolism may predispose for treatment-related weight gain.

Circulating microRNAs associated with prolonged overall survival in lung cancer patients treated with nivolumab

Abstract Background: The introduction of immune check-point inhibition in non-small cell lung cancer (NSCLC) therapy represents improved prospects for the patients. The response rates to check-point inhibitors are approximately 20% in unselected NSCLC patients. Increasing levels of tumor PD-L1 expression are associated with higher response rates. However, patients with low PD-L1 levels may also have durable responses, and improved strategies for patient stratification are needed. Material and methods: In this study, we investigated circulating microRNAs aiming to identify circulating predictive biomarkers associated with increased overall survival after immune check-point treatment. Using next generation sequencing, we performed microRNA profiling in serum from NSCLC patients (n = 20) treated with nivolumab. Serum samples from 31 patients were used for validation using qPCR assays. Serum samples were collected prior to immune therapy initiation. Results: Based on multivariate regression analysis, we identified a signature of seven microRNAs (miR-215-5p, miR-411-3p, miR-493-5p, miR-494-3p, miR-495-3p, miR-548j-5p and miR-93-3p) significantly associated with overall survival (OS) > 6 months in discovery cohort (p = .0003). We further validated this in another similar set of samples (n = 31) and the model was significantly associated with overall survival (OS) > 6 months (p = .001) with sensitivity and specificity of 71% and 90%, respectively. Conclusions: In this study of circulating microRNAs, we have identified a 7-miR signature associated with survival in nivolumab-treated NSCLC patients. This signature may lead to better treatment options for patients with NSCLC, but a validation in an independent cohort is needed to confirm the predicted potential.

Abstract P1-07-06: Weight gain during pre- and postmenopausal years results in earlier onset of breast cancer. The Tromsø cohort study

Background: Obesity is both an independent risk factor, and a prognostic factor of postmenopausal breast cancer. In contrast, the association between premenopausal obesity/leanness, and subsequent weight gain and breast cancer outcomes, is still unclear. Furthermore, the association between adult weight gain, weight and age at diagnosis, and tumor characteristics is less studied. Methods: During 1979-2007, a total of 18 990 women, aged 18-87 years, answered questionnaires and underwent clinical examination at a total of five repeated health surveys (attendance rate 68-82%). Height and weight were measured at each survey, and before surgery, among those women diagnosed with breast cancer during follow-up. Careful review of the respective medical records, including histopathological workup, was performed. Multivariate Cox Proportional Hazard models were used to study the importance of Body Mass Index (BMI kg/m 2 ) and weight change on breast cancer risk, and to evaluate variation in breast tumor characteristics. Results: During a median follow-up of 23.3 years, 579 women with invasive breast cancer were identified, and the cases were histologically verified. These breast cancer cases had a mean age at diagnosis of 56.3 years, and mean BMI at diagnosis of 25.3 kg/m 2 . Most (67 %) of the breast cancer patients had estrogen receptor (ER) positive tumors, 48 % had progesterone receptor (PgR) positive tumors, and 41 % had lymph node positive disease. We divided all participating women in three groups of weight change ( 15 kg). When we compared women with less than 5 kg weight gain, to women with weight gain 5-15 kg, and to women with weight gain above >15kg, we observed a RR of 1.43 (95% CI 1.07-1.90) and a RR of 1.86 (95% CI 1.30-2.68), respectively, for postmenopausal breast cancer. We divided women by quartiles of BMI (kg/m 2 ) at entry, and observed that women in the lowest quartile of BMI (≤ 21.45 kg/m 2 ), who had a subsequent weight gain >15 kg, had a RR of 2.40 (95% CI 1.07-5.38) for postmenopausal breast cancer compared to women with the same BMI at entry, but who remained stabile in weight. We observed a 6 year difference in age at diagnosis for women diagnosed with breast cancer, who at study entry were in the same BMI group ( 2 ), but subsequently either experienced a large weight gain (>15 kg), or remained stabile in weight (59.5 years vs. 64.4 years, p=0.007). Furthermore, we observed a 15 year difference in age at diagnosis for women diagnosed with breast cancer, who at study entry were in the same BMI group (≥ 25kg m 2 ), but subsequently either experienced a large weight gain (> 15 kg), or remained stabile in weight (60.3 years vs. 74.9 years, p=0.007). Conclusion: Avoiding large weight gain during pre- and postmenopausal years may both protect against, and delay onset of postmenopausal breast cancer. Our findings support the importance of weight gain as a modifiable lifestyle factor for early onset of breast cancer. Citation Format: Lofterod T, Frydenberg H, Flote VG, Risberg T, Eggen AE, McTiernan A, Mortensen E, Wist EA, Akslen LA, Reitan JB, Wilsgaard T, Thune I. Weight gain during pre- and postmenopausal years results in earlier onset of breast cancer. The Tromso cohort study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-07-06.

Abstract P6-08-37: Cardiorespiratory fitness (VO2max) before, during and after adjuvant treatment in breast cancer patients

Background: Breast cancer treatment may result in reduced exercise capacity that may in turn lead to reduced maximum oxygen consumption (VO 2max ). However, whether physical exercise can counteract any observed decline in VO 2max in breast cancer patients undergoing adjuvant breast cancer treatment, is less known. Material & methods: The women participating in the Norwegian Energy Balance and Breast Cancer Aspect (EBBA)-II pilot study, were aged 35-75 years and diagnosed with stage I-II breast cancer. Performing a maximum exercise test on a treadmill (modified Balke protocol), VO 2max was assessed at four times; preoperative, 6, 12 and 24 months postoperative. The patients were randomized postoperative to a control group (n=31) or an intervention group (n=29) stratified by menopausal status. The 12 months exercise intervention program consisted of group-based exercise, 60 minutes twice a week and a minimum of 60 minutes of individual exercise. Regression models were used to study the associations between treatment regime and VO 2max . Results: Breast cancer patients (n=60) with a mean age at diagnosis of 55.3 years (38.0-69.0 years), had a mean body mass index of 25.1 kg/m2, and a mean preoperative VO 2max of 32.4 ml/min/kg. Comparing the intervention group to the control group, the intervention group maintained VO 2max throughout the treatment period, and improved their VO 2max with 7.8 % from 12 to 24 months postoperative (p=0.117), while the control group had a 15% reduction in VO 2max 6 months after surgery (p 2max of 22.9 % (p 2max at 6 months postoperative (p = 0.159). Thereafter, in the control group, VO 2max improved with 21.6 % at 12 months postoperative (p=0.006), while in the intervention group VO 2max improved with 13.4 % 24 months postoperative (p=0.038). Patients in the intervention group who did not receive any chemotherapy increased their VO 2max by 6% 6 months postoperative (p=0.174), while patients in the control group who did not receive any chemotherapy had a reduction in VO 2max of 2.1 % at 6 month postoperative (p=0.630). Conclusion: Our findings suggest that systematic physical training may counteract a decline in VO 2max in breast cancer patients receiving adjuvant treatment, including chemotherapy, and is of clinical interest, but needs to be replicated in larger studies. Citation Format: Hanne Frydenberg, Tora J Bettum, Trygve Lofterod, Elisabeth Edvardsen, Vidar G Flote, Sissi E Finstad, Gro F Bertheussen, Ellen Schlichting, Anne McTiernan, Inger Thune. Cardiorespiratory fitness (VO 2max ) before, during and after adjuvant treatment in breast cancer patients [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P6-08-37.

Abstract 1362: Dyslipidemia, excess weight and high mammographic density are associated with high levels of daily estrogen and progesterone. .

Background: Dyslipidemia, excess weight, and high mammographic density have independently been associated with breast cancer development. However, little is known regarding the combined effect of dyslipidemia, excess weight and mammographic density on cyclic variation in estrogen and progesterone. Material and Methods: 202 premenopausal women (25-35 years) participated in the Norwegian EBBA-I study including clinical examinations, and fasting blood sampling. Computer-assisted percent mammographic density (Madena) was obtained from digitized mammograms taken at day 7-12 of menstrual cycle. Daily saliva samples were collected across an entire menstrual cycle, and concentrations of 17β-estradiol and progesterone were measured at the Reproductive Ecology Laboratory, Harvard University, USA. Uni and multivariable linear and logistic regression models were used to study the combined association of high-density lipoprotein cholesterol (HDL-C), body mass index (BMI) and mammographic density with daily concentrations of 17β-estradiol and progesterone. Results: Among women with mean age of 30.7 years, mean percent mammographic density 29.8 %, mean BMI 24.4 kg/m 2 , mean total cholesterol 4.45 mmol/l, and mean HDL-C 1.54 mmol/l, we observed overall mean salivary 17β-estradiol 16.2 pmol/l and progesterone 129.3 pmol/l. We used median split and women characterized by lower than median HDL-C (≤ 1.51 mmol/l), higher than median BMI (> 23.6 kg/m 2 ), and higher than median percent mammographic density (> 28.5 %) (unfavorable profile), had higher concentrations of both 17β-estradiol (p = 0.005) and progesterone (p = 0.016) across the entire menstrual cycle, compared with women characterized by higher HDL-C(> 1.51 mmol/l), lower BMI (≤ 23.6 kg/m 2 ) and lower percent mammographic density (≤ 28.5 %) (favorable profile). Comparing the profiles, women with an unfavorable profile had 46 % higher overall mean 17β-estradiol (17β-estradiol; 22.2 versus 15.9 pmol/l) and 48% higher overall mean progesterone (progesterone; 187.5 versus 126.1pmol/l). These factors also showed strong associations with differences in AUC (area under curve) of these sex steroid hormones across the entire menstrual cycle, reflecting cumulative exposure. Women characterized by unfavorable profile had 48 % higher AUC estradiol compared with women having favorable profile (AUC e , 387, 95 % confidence interval (CI) 244 - 531 versus 262, 95% CI 244 - 281). Furthermore, women with unfavorable profile had 47 % higher AUC progesterone than women with favorable profile (AUC p , 1929, 95 % CI 1125 - 2733 versus 1309, 95% CI 1211 -1408). Conclusion: A combination of low HDL-C, excess weight, and high percent mammographic density, was strongly associated with higher daily levels of 17β-estradiol and progesterone, and could in part explain the association of these factors with increased risk of breast cancer development. Citation Format: Vidar G. Flote, Hanne Frydenberg, Giske Ursin, Anita Iversen, Morten W. Fagerland, Peter T. Ellison, Erik A. Wist, Thore Egeland, Anne-Sofie Furberg, Inger Thune. Dyslipidemia, excess weight and high mammographic density are associated with high levels of daily estrogen and progesterone. . [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1362. doi:10.1158/1538-7445.AM2013-1362