The influence of metabolic factors and ethnicity on breast cancer risk, treatment and survival: The Oslo ethnic breast cancer study

BACKGROUND

Breast cancer risk remains higher in high-income compared with low-income countries. However, it is unclear to what degree metabolic factors influence breast cancer development in women 30 years after immigration from low- to a high-incidence country.

METHODS

Using Cox regression models, we studied the association between pre-diagnostic metabolic factors and breast cancer development, and whether this association varied by ethnicity among 13,802 women participating in the population-based Oslo Ethnic Breast Cancer Study. Ethnic background was assessed and pre-diagnostic metabolic factors (body mass index, waist:hip ratio, serum lipids and blood pressure) were measured. A total of 557 women developed invasive breast cancer, and these women were followed for an additional 7.7 years.

RESULTS

Among women with an unfavorable metabolic profile, women from south Asia, compared with western European women, had a 2.3 times higher breast cancer risk (HR 2.30, 95% CI 1.18-4.49). Compared with the western European women, the ethnic minority women were more likely to present with triple-negative breast cancer (TNBC) (OR 2.11, 95% CI 0.97-4.61), and less likely to complete all courses of planned taxane treatment (OR 0.26, 95% CI 0.08-0.82). Among TNBC women, above-median triglycerides:HDL-cholesterol (>0.73) levels, compared with below-median triglycerides:HDL-cholesterol (≤0.73) levels, was associated with 2.9 times higher overall mortality (HR 2.88, 95% CI 1.02-8.11).

CONCLUSIONS

Our results support the importance of metabolic factors when balancing breast cancer prevention and disease management among all women, and in particular among non-western women migrating from a breast cancer low-incidence to a high-incidence country.

Abstract P3-14-08: The influence of metabolic factors, migration, and ethnic disparities on breast cancer risk and treatment

Background: Migrant studies have shown an increase in breast cancer incidence rates among immigrants moving from a breast cancer low-incidence to a high-incidence country. However, 30 years after immigration, it remains equivocal to what degree metabolic factors and ethnic disparities affect breast cancer development and treatment. Methods: Using Cox regression models, we examined the association between ethnicity and breast cancer development, and whether this association varied by pre-diagnostic metabolic profiles among 13 802 women, aged 20-75 years, participating in the population-based Oslo Ethnic Breast Cancer Study. Ethnicity was categorized into: women of Western European descent (reference population) and women of non-western ethnicity (ethnic minority). The ethnic minority women were further subclassified into three groups: 1) South Asian, 2) Middle East and North African, and 3) all other non-western origin women. We defined four pre-diagnostic unfavorable metabolic factors (above median body mass index (>24.6 kg/m2), waist:hip ratio (>0.79), triglyceride:HDL-cholesterol ratio (>0.73), and blood pressure (>96.5 mmHg)), which were combined to define three metabolic profiles: (0-2, 3, and 4 unfavorable metabolic factors). A total of 557 women developed invasive breast cancer during a mean 16.5 years of follow-up. Detailed medical records were obtained. Results: Among women with an unfavorable metabolic profile, South Asian women, compared with Western European women, had a 2.3 times higher breast cancer risk (HR 2.30, 95% CI 1.18-4.49). Furthermore, the ethnic minority women, compared with the Western European women, were suggestively more likely to present with triple-negative breast cancer (OR 2.11, 95% CI 0.97-4.61), and less likely to complete all courses of planned taxane treatment (OR 0.26, 95% CI 0.08-0.82). No differences by ethnicity were observed in physicians’ decisions of planned breast cancer treatment, Conclusions: Our results support that metabolic factors, including body composition, serum lipids and blood pressure, are important when balancing breast cancer prevention and disease management among non-western women migrating from a breast cancer low-incidence to a high-incidence country. However, larger studies are needed.

Citation Format: Trygve Lofterød, Hanne Frydenberg, Marit Veierød, Anne Karen Jenum, Jon B Reitan, Erik Wist, Inger Thune. The influence of metabolic factors, migration, and ethnic disparities on breast cancer risk and treatment [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-14-08.

Effects of a 1-Year Physical Activity Intervention on Markers of Hemostasis among Breast Cancer Survivors: A Randomized Controlled Trial

Introduction  Physical activity may reduce the development of breast cancer. Whereas hypercoagulability has been linked to adverse outcomes in breast cancer patients, the effects of physical activity on their hemostatic factors are unknown. The study aimed to assess whether long-term (1 year) physical activity can affect hemostatic factors in breast cancer patients. Methods  Fifty-five women (35-75 years) with invasive breast cancer stage I/II were randomized to a physical activity intervention ( n  = 29) lasting 1 year or to a control group ( n  = 26), and analyzed as intention to treat. Fibrinogen, factor VII antigen, tissue factor pathway inhibitor, and von Willebrand factor (VWF) antigen as well as prothrombin fragment 1 + 2, the endogenous thrombin potential and D-dimer, were measured in plasma before intervention (baseline), and then after 6 and 12 months. Results  Maximal oxygen uptake (measure of cardiorespiratory fitness) decreased the first 6 months among the controls, but remained stable in the intervention group. We found no significant differences between the two study groups regarding any of the hemostatic factors, except a significantly higher increase in factor VII antigen in the intervention group. The effect of the intervention on VWF was, however, significantly affected by menopausal stage, and a significant effect of the intervention was found on VWF among postmenopausal women, even after adjustment for dietary intake. Conclusion  Long-term physical activity had no effect on the majority of the hemostatic factors measured, but led to increased plasma concentrations of factor VII antigen and prevented an increase in VWF concentration after breast cancer treatment in postmenopausal women. The clinical impact of these findings for risk of vascular thrombosis warrants further studies.

Exploring the effects of lifestyle on breast cancer risk, age at diagnosis, and survival: the EBBA-Life study

Purpose

Whether an unfavorable lifestyle not only affects breast cancer risk, but also influences age at onset of breast cancer and survival, is under debate.

Methods

In a population-based cohort, the Energy Balance and Breast Cancer Aspects throughout life (EBBA-Life) study, a total of 17,145 women were included. During follow-up, 574 women developed invasive breast cancer. Breast cancer cases were followed for an additional 9.1 years. Detailed medical records were obtained. Cox’s proportional hazard regression models were used to study the association between pre-diagnostic lifestyle factors (weight, physical activity, alcohol use, smoking, and hypertension), breast cancer risk, age at diagnosis, and survival.

Results

At study entry, 34.3% of the participating women were overweight and 30.7% were physically inactive. Mean age at breast cancer diagnosis was 58.0 years, and 78.9% of the tumors were estrogen receptor positive. Among menopausal women who did not use hormone therapy and had an unfavorable lifestyle (3–5 unfavorable factors), compared with women who had a favorable lifestyle, we observed a twofold higher risk for postmenopausal breast cancer (hazard ratio [HR] 2.13, 95% confidence interval [CI] 1.23–3.69), and they were 3.4 years younger at diagnosis (64.8 versus 68.2 years, P = 0.032). Breast cancer patients with an unfavorable lifestyle, compared with patients with a favorable lifestyle, had almost a two times higher overall mortality risk (HR 1.96, 95% CI 1.01–3.80).

Conclusions

Our study supports a healthy lifestyle improving breast cancer prevention, postponing onset of disease, and extending life expectancy among breast cancer patients.

Electronic supplementary material

The online version of this article (10.1007/s10549-020-05679-2) contains supplementary material, which is available to authorized users.

Abstract P1-13-01: Lipoprotein and metabolite responses to physical exercise during adjuvant breast cancer treatment

Background: Adjuvant breast cancer treatment may cause metabolic perturbations, such as dyslipidaemia, potentially exacerbating risk of cardiometabolic disease as well as risk of breast cancer recurrence. Physical exercise may have beneficial metabolic effects, but it’s effect on serum lipoprotein- and metabolite profiles during adjuvant breast cancer treatment including chemotherapy is not yet well established.

Methods: The women participating in this pilot study of Energy Balance and Breast Cancer Aspects (EBBA)-II, were aged 38-69 years and diagnosed with stage I-II breast cancer. 60 breast cancer patients were randomized after surgery to a control group (n = 29, usual care) or an intervention group (n = 31, intervention), stratified by menopausal status. The patients in the intervention group received a detailed exercise program and met for supervised training sessions in groups of 10-12 women for 60 minutes twice a week during a 12 month period, and were in addition asked to perform at least 60 minutes of exercise at home (a total of 180 minutes of exercise weekly). Fasting serum samples were collected pre-surgery and after six months, and analysed by nuclear magnetic resonance (NMR)-spectroscopy and mass spectrometry. 170 metabolites and 109 lipoprotein subclass variables were quantified and analysed using orthogonalized partial least squares discriminant analysis. Statistical significance was assessed by permutation testing. Single variables were tested with Mann Whitney U-tests or multiple linear regression (NCT02240836).

Results: The breast cancer patients (n = 60) had at pre-surgery the following means: Age at diagnosis of 55.4 years (38-69 years), low density lipoprotein (LDL)-cholesterol 145.4 mg/dl (3.76 mmol/L), high density lipoprotein (HDL)-cholesterol 70.4 mg/dl (1.82 mmol/L), and triglycerides 101.9 mg/dl (1.15 mmol/L), and 58.3 % of the patients underwent chemotherapy (paclitaxel/docetaxel/5-FU/epirubicin/cyclophosphamide based adjuvant chemotherapy). Physical exercise ameliorated chemotherapy-induced increases in very low density lipoprotein (VLDL)- and intermediate density lipoprotein (IDL)-associated lipids, and reduced triglyceride enrichment in LDL and HDL compared with chemotherapy controls (p = 0.003). Physical exercise also significantly increased apoA1 (4.6 % increase vs 11.3 % decrease, q = 0.02) and apoA2 (5.2 % increase vs 13.0 % decrease, q = 0.01) compared with chemotherapy control patients. The NMR-measured lipid signal at 1.55-1.60 ppm increased after six months in chemotherapy recipients, but this was attenuated among chemotherapy recipients in the intervention group. No statistically significant effect of physical exercise on serum levels of small-molecular metabolites was detected.

Conclusion: Our findings suggest that physical exercise may prevent atherogenic alterations in lipoprotein profile induced by chemotherapy. The results indicate increased HDL particle number- and function, as well as increased triglyceride clearance in the intervention group. Thus, atherogenic alterations in lipoprotein profile may play a role in evaluating breast cancer treatment, and could potentially be biomarkers of importance for breast cancer prognosis and co-morbidity.

Citation Format: Torfinn Støve Madssen, Vidar Gordon Flote, Inger Thune, Gro Falkener Bertheussen, Anders Husøy, Steinar Lundgren, Hanne Frydenberg, Erik Wist, Ellen Schlichting, Jon Lømo, Anne McTiernan, Tone Frost Bathen, Guro Fanneløb Giskeødegård. Lipoprotein and metabolite responses to physical exercise during adjuvant breast cancer treatment [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P1-13-01.

Abstract GS5-02: Cardiovascular function and the effect of exercise training during adjuvant breast cancer treatment. Results from The EBBA-II trial

Background: Breast cancer survival rates have improved, but cardiovascular disease is a competing cause of death among breast cancer survivors, and treatment-induced cardio-toxicity remains a major concern. The effect of aerobic exercise on cardiovascular function during adjuvant breast cancer treatment is not yet well established.

Material & methods: The women participating in the Energy Balance and Breast Cancer Aspect (EBBA)-II trial are aged 18-75 years and diagnosed with stage I-II breast cancer. VO2max was assessed at three separate times, prior to surgery and at 6 and 12 months after, using a maximum exercise test on a treadmill (modified Balke protocol).The patients were randomized after surgery to a control group (n=188, usual care) or an intervention group (n=187) stratified by menopausal status. The 12 months exercise intervention program started 2-3 weeks after surgery and the patients received a detailed training program based on their own VO2max at baseline. They met for training sessions in groups of 10-12 women for 60 minutes twice a week during a 12 month period, and were in addition asked to perform at least 120 minutes of exercise at home (a total of 240 minutes of exercise weekly).Analyses were done on an intention-to-treat basis (NCT02240836).

Preliminary results: Breast cancer patients (n=375) with a mean age at diagnosis of 55.2 years (27.0-75.0 years) had a mean body mass index (BMI) of 25.1kg/m2, a mean VO2max before surgery of 31.5 ml•min−1•kg−1, and 57 % of the patients underwent chemotherapy (paclitaxel, epirubicin/cyclophosphamide based adjuvant chemotherapy). Comparing the intervention group to the control group, the intervention group had a decrease in VO2max of 2.7% after 6 months, but they improved their VO2max by 2.3 % at 12 months compared to before surgery (p=0.001). Breast cancer patients in the control group had a 10 % reduction in VO2max 6 months after surgery (p<0.001), and a 3.8% decrease in VO2max was observed at 12 months compared to before surgery (p<0.001). Among patients in the control group who received chemotherapy, a decline in VO2max by 5.3 ml•min−1•kg−1 (16.2%) (p<0.001) at 6 months was observed. This reduction in VO2max at 6 months was most pronounced in patients who received paclitaxel alone, or paclitaxel in combination with epirubicin/cyclophosphamide (6.1 ml•min−1•kg−1, 18.7% decrease). In comparison, patients in the intervention group who received chemotherapy had a decline of 2.4 ml•min−1•kg−1 (7.6%) in VO2max at 6 and after 12 months VO2max was equal to before surgery. Differences in VO2max at 6 and after 12 month between groups were in favor of the intervention group (p<0.05).

Conclusion: Our findings strongly support that tailored exercise training during adjuvant breast cancer treatment may counteract a decline in cardiovascular function, and in particular among those receiving chemotherapy. Our study supports incorporation of supervised clinical exercise programs into breast cancer treatment guidelines.

Final results of the trial at SABCS 2018 (the trial closes October 15, 2018) total included N=539 (NCT02240836)

Citation Format: Thune I, Husøy A, Frydenberg H, Flote VG, Fjeldheim F, Bertheussen GF, Lundgren S, Lømo J, Wist EA, McTiernan A, Schlichting E. Cardiovascular function and the effect of exercise training during adjuvant breast cancer treatment. Results from The EBBA-II trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr GS5-02.

Validation of repeated self-reported n-3 PUFA intake using serum phospholipid fatty acids as a biomarker in breast cancer patients during treatment

Background

The role of n-3 polyunsaturated fatty acids (PUFAs) in breast cancer is not clear and under debate. To explore this relationship it is important to have proper validated dietary assessment methods for measuring the intake of n-3 PUFAs. The aim of the current study is to validate two different methods used to assess the intake of selected n-3 PUFAs as well as food sources of long-chained n-3 PUFAs. Also, we aim to study how stable the intake of fatty acids is during breast cancer treatment.

Methods

The study-population was patients with breast cancer (Stages I-II) or ductal carcinoma in situ (DCIS-grade III) undergoing treatment (n = 49) in Norway. Dietary intake was assessed by two self-administered methods, a 256 food item food frequency questionnaire (FFQ) and a 7-day pre-coded food diary (PFD). The FFQ was administered presurgery and twelve months postsurgery, and the PFD was administered shortly after surgery (10 +/− 2 days), six and twelve months postsurgery. Fasting blood samples (presurgery, six and twelve months postsurgery) were analysed for serum phospholipid fatty acids, a biomarker for intake of n-3 PUFAs.

Results

Mean (SD) age was 54.2 (7.8) years at diagnosis, and the mean (SD) body mass index (BMI) was 24.8 (3.4) kg/m². Correlation coefficients between dietary intakes of n-3 PUFAs measured with the FFQ and the PFD ranged from 0.35 to 0.66. The correlation coefficients between the PFD and the biomarker (serum phospholipid n-3 PUFAs) as well as between the FFQ and the biomarker demonstrated stronger correlations twelve months after surgery (ρ 0.40–0.56 and 0.36–0.53, respectively) compared to around surgery (ρ 0.08–0.20 and 0.28–0.38, respectively). The same pattern was observed for intake of fatty fish. The intake of n-3 PUFAs did not change during treatment assessed by the FFQ, PFD or biomarker.

Conclusion

These results indicate that the FFQ and the PFD can be used to assess dietary intake of fish and n-3 PUFAs in breast cancer patients during breast cancer treatment. Still, the PFD shortly after surgery should be used with caution. The diet of patients undergoing breast cancer treatment was quite stable, and the intake of n-3 PUFAs did not change.

Electronic supplementary material

The online version of this article (10.1186/s12937-018-0402-6) contains supplementary material, which is available to authorized users.

Impact of pre-diagnostic triglycerides and HDL-cholesterol on breast cancer recurrence and survival by breast cancer subtypes

BACKGROUND

High triglycerides and low levels of high density lipoprotein (HDL)-cholesterol are observed to promote tumor growth. However, whether breast cancer heterogeneity may explain the contradictory influence of triglycerides and cholesterol observed on breast cancer prognosis remains unclear.

METHODS

A population-based survival study among 464 breast cancer cases identified within the Tromsø study was conducted. Pre-diagnostic triglycerides, total-cholesterol and HDL-cholesterol were measured, and detailed clinical and histopathological data were obtained. Using tissue microarray, all breast cancer cases were reclassified into the following subtypes: Luminal A, Luminal B, HER2-enriched, and triple negative breast cancer (TNBC). Multivariable Cox proportional hazards regression models were used to study the associations between pre-diagnostic lipids and breast cancer recurrence, mortality, and survival.

RESULTS

A total of 464 breast cancer patients, with mean age at diagnosis of 57.9 years, were followed for a mean 8.4 years. TNBC patients in the highest tertile of triglycerides (≥ 1.23 mmol/l) had 3 times higher overall mortality compared to TNBC patients in the lowest tertile (≤ 0.82 mmol/l) (HR 2.99, 95% CI 1.17-7.63), and the 5-year overall survival was 19% lower for TNBC patients in the highest vs. lowest tertile of triglycerides (65% vs. 84%). TNBC patients in the highest tertile of the HDL-cholesterol/total-cholesterol ratio (≥0.35), compared to those in the lowest tertile (≤0.27), had a 67% reduced overall mortality risk (HR 0.33, 95% CI 0.12-0.89). No associations were observed between lipids and prognostic outcome among breast cancer patients overall, or among patients with luminal A and luminal B subtypes. Among HER2-enriched patients, pre-diagnostic triglyceride level was inversely associated with overall mortality.

CONCLUSION

Our study suggests that pre-diagnostic triglycerides and the HDL-cholesterol/total-cholesterol ratio may independently provide unique information regarding prognostic outcome among triple negative breast cancer patients. However, a small sample size underlines the need for additional studies.

Inflammation of mammary adipose tissue occurs in overweight and obese patients exhibiting early-stage breast cancer

Growing evidence indicates that adiposity is associated with breast cancer risk and negatively affects breast cancer recurrence and survival, a paracrine role of mammary adipose tissue being very likely in this process. In contrast to other adipose depots, occurrence of a sub-inflammatory state of mammary adipose tissue defined by dying adipocytes surrounded by macrophages forming crown-like structures in overweight and obese subjects, remains only partially described. In a general population of breast cancer patients (107 patients) mostly undergoing breast-conserving surgery, we found a positive association between patient's body composition, breast adipocytes size, and presence of crown-like structures in mammary adipose tissue close to the tumor. Overweight (BMI: 25.0-29.9 kg/m²) and obese (BMI ≥ 30.0 kg/m²) patients have 3.2 and 6.9 times higher odds ratio of crown-like structures respectively, compared with normal weight patients. The relatively small increase in adipocyte size in crown-like structures positive vs. negative patients suggests that mammary adipose tissue inflammation might occur early during hypertrophy. Our results further highlight that body mass index is an adequate predictor of the presence of crown-like structures in mammary adipose tissue among postmenopausal women, whereas in premenopausal women truncal fat percentage might be more predictive, suggesting that mammary adipose tissue inflammation is more likely to occur in patients exhibiting visceral obesity. Finally, the presence of crown-like structures was positively associated with systemic markers such as the Triglyceride/High-density lipoprotein-cholesterol ratio serum C-reactive protein and glucose/(HbA1c) glycated Haemoglobin. These compelling results demonstrate that excess adiposity, even in overweight patients, is associated with mammary adipose tissue inflammation, an event that could contribute to breast cancer development and progression.

Abstract P4-12-02: Serum-triglycerides among triple negative breast cancer patients as a biomarker of poor outcome

Backgound: Obesity and related metabolic imbalances, including increased activity of free fatty acids, may promote tumor growth and metastasis. Fatty acids are mainly stored as triacylglycerols. Yet, the role of serum-triglycerides on breast cancer prognosis is still undefined.

Methods: A population based survival study among 575 breast cancer patients identified within the Tromsø study during 1979-2008, was conducted. Pre-diagnostic serum triglycerides, high density lipoprotein-cholesterol, total cholesterol, height and weight were measured. Histopathological and clinical data were obtained from medical records, and hormone receptor, HER2 status, and Ki-67 were re-analyzed on tissue microarray blocks. Multivariate Cox proportional Hazard regression models were used to study the associations between patient characteristics including s-triglycerides, and breast cancer survival.

Results: Among 575 women with invasive breast cancer (stage 1-3), a total of 87 women were diagnosed with triple negative breast cancer (TNBC). Patients diagnosed with TNBC, compared to non-TNBC, were likely to be younger at diagnosis (55.3 vs 57.9 years, p=0.061), they had larger tumors (29.7 mm vs 22.5 mm, p=0.001), and higher Ki-67 (31.1% vs 15.9%, p<0.001). After a mean follow-up of 8.4 years, TNBC patients with above median levels of s-triglycerides (> 0.98mmol/L) compared to TNBC patients with below median levels of s-triglycerides (≤ 0.98mmol/L) had 3.0 times higher risk for breast cancer recurrence or breast cancer specific death (HR 3.02, 95% CI 1.21-7.55), and 3.4 times higher overall mortality risk (HR 3.41, 95% CI 1.38-8.45). Among the TNBC patients, women with above median s-triglycerides had 15% lower 5-year disease-free survival (76% vs 91%) and 18% lower 5-year overall survival (74% vs 92%) compared to women with below median s-triglycerides.

Conclusions: Our results strongly support s-triglycerides as an important biomarker for breast cancer outcomes among triple negative breast cancer patients.

Table 1: Multivariable adjusted Hazard Ratios (HRs) for incidence breast cancer recurrence or breast cancer specific death, and incidence overall mortality by pre-diagnostic serum-triglycerides among non-triple negative breast cancer (TNBC) and TNBC patients  Non-TNBC, n=488 TNBC, n=87  Recurrence or breast cancer specific death (n=90)Overall mortality (n=104) Recurrence or breast cancer specific death (n=24)Overall mortality (n=33) nHR (95% CI)HR (95% CI)nHR (95% CI)HR (95% CI)s-Triglycerides      Median      ≤ 0.98 mmol/l2571.001.00431.001.00> 0.98 mmol/l2310.87 (0.56-1.35)1.06 (0.70-1.62)443.02 (1.21-7.55)3.41 (1.38-8.45)       Tertiles      ≤ 0.82 mmol/l1731.001.00261.001.000.83 – 1.22 mmol/l1660.74 (0.44-1.23)0.81 (0.49-1.36)311.37 (0.38-4.98)0.98 (0.31-3.08)≥ 1.23 mmol/l1490.88 (0.50-1.54)1.17 (0.66-1.96)306.63 (1.64-19.3)3.87 (1.52-12.0)p-trend 0.4950.357 0.0050.007       Multivariate Cox proportional Hazard regression model. Adjusted for BMI and age at attendance (continuous), age at diagnosis (continuous), breast cancer stage at diagnosis (categorical), and current smoking (categorical). Abbreviation: CI, confidence interval; n, number of cases; TNBC, triple negative breast cancer

Citation Format: Lofterød T, Mortensen ES, Nalwoga H, Wilsgaard T, Frydenberg H, Risberg T, Eggen AE, McTiernan A, Aziz S, Wist EA, Reitan JB, Akslen LA, Thune I. Serum-triglycerides among triple negative breast cancer patients as a biomarker of poor outcome [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-12-02.

Polymorphisms in the estrogen receptor alpha gene (ESR1), daily cycling estrogen and mammographic density phenotypes

Background

Single nucleotide polymorphisms (SNPs) involved in the estrogen pathway and SNPs in the estrogen receptor alpha gene (ESR1 6q25) have been linked to breast cancer development, and mammographic density is an established breast cancer risk factor. Whether there is an association between daily estradiol levels, SNPs in ESR1 and premenopausal mammographic density phenotypes is unknown.

Methods

We assessed estradiol in daily saliva samples throughout an entire menstrual cycle in 202 healthy premenopausal women in the Norwegian Energy Balance and Breast Cancer Aspects I study. DNA was genotyped using the Illumina Golden Gate platform. Mammograms were taken between days 7 and 12 of the menstrual cycle, and digitized mammographic density was assessed using a computer-assisted method (Madena). Multivariable regression models were used to study the association between SNPs in ESR1, premenopausal mammographic density phenotypes and daily cycling estradiol.

Results

We observed inverse linear associations between the minor alleles of eight measured SNPs (rs3020364, rs2474148, rs12154178, rs2347867, rs6927072, rs2982712, rs3020407, rs9322335) and percent mammographic density (p-values: 0.002–0.026), these associations were strongest in lean women (BMI, ≤23.6 kg/m^2.). The odds of above-median percent mammographic density (>28.5 %) among women with major homozygous genotypes were 3–6 times higher than those of women with minor homozygous genotypes in seven SNPs. Women with rs3020364 major homozygous genotype had an OR of 6.46 for above-median percent mammographic density (OR: 6.46; 95 % Confidence Interval 1.61, 25.94) when compared to women with the minor homozygous genotype. These associations were not observed in relation to absolute mammographic density. No associations between SNPs and daily cycling estradiol were observed. However, we suggest, based on results of borderline significance (p values: 0.025–0.079) that the level of 17β-estradiol for women with the minor genotype for rs3020364, rs24744148 and rs2982712 were lower throughout the cycle in women with low (<28.5 %) percent mammographic density and higher in women with high (>28.5 %) percent mammographic density, when compared to women with the major genotype.

Conclusion

Our results support an association between eight selected SNPs in the ESR1 gene and percent mammographic density. The results need to be confirmed in larger studies.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2804-1) contains supplementary material, which is available to authorized users.

Abstract 3925: Crown-like structures and adipocyte size in fat tissue adjacent to breast tumor reflect parameters of obesity, dyslipidemia and serum high-sensitivity C-reactive protein

Background: Adult weight gain and obesity have consistently been associated with breast cancer development but the biological mechanisms operating remain unclear. Adipose tissue may develop low-grade inflammation, observed as apoptotic adipocytes surrounded by macrophages forming characteristic crown-like structures (CLS). We questioned whether CLS and adipocyte size in breast fat tissue are biomarkers of patient's body fat distribution, dyslipidemia and serum high-sensitivity C-reactive protein (hs-CRP), factors associated with breast cancer development.

Material and Methods: Among 55 women, aged 35-75 years, with newly diagnosed invasive breast cancer (stage I/II), measurements of body composition: waist to hips ratio (WHR), body mass index (BMI, kg/m2) and total fat percentage (DEXA,%) were assessed. Concentrations of lipids (cholesterol, triglycerides) and hs-CRP were determined in fasting serum blood samples. Surgical specimens of breast tumours with surrounding fat tissue were examined in Haematoxylin Eosin and CD68 stained slides to assess the size of adipocytes (μm) and CLS density (CLS/cm2). We used linear regression models to study the association between mammary adipose tissue parameters, body composition, serum lipids and inflammatory markers.

Results: The breast cancer patients had the following means: age at diagnosis, 55.2 years, BMI, 25.2 kg/m2, WHR, 0.88, truncal fat, 38.1%, total cholesterol, 5.76 mmol/l, triglycerides, 1.19 mmol/l and hs-CRP 1.75 mg/L. The mean tumour size was 16.3 mm, 93% of tumors were estrogen receptor positive and 82% were progesterone receptor positive. Mean adipocyte size was 68.0 μm and mean CLS density was 0.12 CLS/cm2. Adipocyte size and CLS density were positively associated with BMI (padipocytes = 0.004, pCLS-density = 0.008), WHR (padipocytes = 0.003, pCLS-density = 0.009) and truncal fat (padipocytes&lt;0.001, pCLS-density = 0.005). Overweight/obese patients (BMI ≥25 kg/m2) compared with normal weighted patients, had higher of cholesterol (p = 0.016), triglyceride (p&lt;0.001), hs-CRP (p = 0.001) and had higher levels of CLS density (p = 0.002) and larger adipocytes (p = 0.003).

Conclusion: Breast adipose tissue markers such as adipocyte size and CLS, reflecting local low-grade inflammation, were positively associated with excess weight, truncal fat, dyslipidemia and a high level of hs-CRP. In addition to the systemic effect, it is conceivable that fat tissue inflammation in the vicinity of the breast cancer can influence events in a paracrine manner. These findings point to important biomarkers in breast tissue that may co-exist with serum biomarkers associated with breast cancer development.

Citation Format: Charlotte Vaysse, Inger Thune, Øystein Garred, Catherine Muller, Ellen Schlichting, Frøydis Fjeldheim, Anne McTiernan, Hanne Frydenberg, Anders Husøy, Steinar Lundgren, Morten W Fagerland, Erik A Wist, Jon Lømo. Crown-like structures and adipocyte size in fat tissue adjacent to breast tumor reflect parameters of obesity, dyslipidemia and serum high-sensitivity C-reactive protein. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3925.

Lipoprotein subfractions by nuclear magnetic resonance are associated with tumor characteristics in breast cancer

Background

High-Density Lipoprotein (HDL)-cholesterol, has been associated with breast cancer development, but the association is under debate, and whether lipoprotein subfractions is associated with breast tumor characteristics remains unclear.

Methods

Among 56 women with newly diagnosed invasive breast cancer stage I/II, aged 35–75 years, pre-surgery overnight fasting serum concentrations of lipids were assessed, and body mass index (BMI) was measured. All breast tumors were immunohistochemically examined in the surgical specimen. Serum metabolomics of lipoprotein subfractions and their contents of cholesterol, free cholesterol, phospholipids, apolipoprotein-A1 and apolipoprotein-A2, were assessed using nuclear magnetic resonance. Principal component analysis, partial least square analysis, and uni- and multivariable linear regression models were used to study whether lipoprotein subfractions were associated with breast cancer tumor characteristics.

Results

The breast cancer patients had following means: age at diagnosis: 55.1 years; BMI: 25.1 kg/m²; total-Cholesterol: 5.74 mmol/L; HDL-Cholesterol: 1.78 mmol/L; Low-Density Lipoprotein (LDL)-Cholesterol: 3.45 mmol/L; triglycerides: 1.18 mmol/L. The mean tumor size was 16.4 mm, and the mean Ki67 hotspot index was 26.5 %. Most (93 %) of the patients had estrogen receptor (ER) positive tumors (≥1 % ER+), and 82 % had progesterone receptor (PgR) positive tumors (≥10 % PgR+). Several HDL subfraction contents were strongly associated with PgR expression: Apolipoprotein-A1 (β 0.46, CI 0.22–0.69, p < 0.001), HDL cholesterol (β 0.95, CI 0.51–1.39, p < 0.001), HDL free cholesterol (β 2.88, CI 1.28–4.48, p = 0.001), HDL phospholipids (β 0.70, CI 0.36–1.04, p < 0.001). Similar results were observed for the subfractions of HDL1-3. We observed inverse associations between HDL phospholipids and Ki67 (β -0.25, p = 0.008), and in particular between HDL1’s contents of cholesterol, phospholipids, apolipoprotein-A1, apolipoprotein-A2 and Ki67. No association was observed between lipoproteins and ER expression.

Conclusion

Our findings hypothesize associations between different lipoprotein subfractions, and PgR expression, and Ki 67 % in breast tumors. These findings may have clinical implications, but require confirmation in larger studies.

Electronic supplementary material

The online version of this article (doi:10.1186/s12944-016-0225-4) contains supplementary material, which is available to authorized users.

Pre-diagnostic high-sensitive C-reactive protein and breast cancer risk, recurrence, and survival

Inflammation may initiate and promote breast cancer development, and be associated with elevated circulating levels of inflammation markers. A total of eight 130 initially healthy women, participated in the population-based Tromsø study (1994-2008). Pre-diagnostic high-sensitivity C-reactive protein (hs-CRP) was assessed. During 14.6 years of follow-up, a total of 192 women developed invasive breast cancer. These cases were followed for additional 7.2 years. Detailed medical records were obtained. We observed an overall positive dose-response relationship between pre-diagnostic hs-CRP and breast cancer risk (hazard ratio (HR) = 1.06, 95 % CI 1.01-1.11). Postmenopausal women with above median levels of hs-CRP (>1.2 mg/l) had a 1.42 (95 % CI 1.01-2.00) higher breast cancer risk compared to postmenopausal women with hs-CRP below median. Postmenopausal women, who were hormone replacement therapy non-users, and were in the middle tertile (0.8-1.9 mg/l), or highest tertile of hs-CRP (>1.9 mg/l), had a 2.31 (95 % CI 1.31-4.03) and 2.08 (95 % CI 1.16-3.76) higher breast cancer risk, respectively, compared with women in the lowest tertile. For each unit increase in pre-diagnostic hs-CRP levels (mg/l), we observed an 18 % increase in disease-free interval (95 % CI 0.70-0.97), and a 22 % reduction in overall mortality (95 % CI 0.62-0.98). Our study supports a positive association between pre-diagnostic hs-CRP and breast cancer risk. In contrast, increased pre-diagnostic hs-CRP was associated with improved overall mortality, but our findings are based on a small sample size, and should be interpreted with caution.

Alcohol consumption, endogenous estrogen and mammographic density among premenopausal women

Introduction

Alcohol 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.

Methods

Alcohol 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.

Results

Current 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.

Conclusion

Alcohol 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.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-015-0620-1) contains supplementary material, which is available to authorized users.

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 (VO2max). However, whether physical exercise can counteract any observed decline in VO2max 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), VO2max 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 VO2max.

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 VO2max of 32.4 ml/min/kg. Comparing the intervention group to the control group, the intervention group maintained VO2max throughout the treatment period, and improved their VO2max with 7.8 % from 12 to 24 months postoperative (p=0.117), while the control group had a 15% reduction in VO2max 6 months after surgery (p&lt;0.001), which improved 14 % at 12 months and additionally 6 % at 24 months postoperative (p=0.025). Among those patients receiving chemotherapy (60%), and being in the control group, a decline in VO2max of 22.9 % (p&lt;0.001) at 6 months postoperative was observed. In comparison, patients in the intervention group who received chemotherapy had a 4.5 % reduction in VO2max at 6 months postoperative (p = 0.159). Thereafter, in the control group, VO2max improved with 21.6 % at 12 months postoperative (p=0.006), while in the intervention group VO2max improved with 13.4 % 24 months postoperative (p=0.038). Patients in the intervention group who did not receive any chemotherapy increased their VO2max by 6% 6 months postoperative (p=0.174), while patients in the control group who did not receive any chemotherapy had a reduction in VO2max of 2.1 % at 6 month postoperative (p=0.630).

Conclusion: Our findings suggest that systematic physical training may counteract a decline in VO2max 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 Lofterød, Elisabeth Edvardsen, Vidar G Flote, Sissi E Finstad, Gro F Bertheussen, Ellen Schlichting, Anne McTiernan, Inger Thune. Cardiorespiratory fitness (VO2max) 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.

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 cm(2)). 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.

Women who are married or living as married have higher salivary estradiol and progesterone than unmarried women

OBJECTIVES

Extensive research has demonstrated that marriage and parenting are associated with lower testosterone levels in men, however, very little is known about associations with hormone concentrations in women. Two studies have found lower testosterone in relation to pair-bonding and motherhood in women, with several others suggesting that estradiol levels are lower among parous women than nulliparous women. Here, we examine estradiol and progesterone concentrations in relation to marriage and motherhood in naturally cycling, reproductive age women.

METHODS

In 185 Norwegian women, estradiol and progesterone concentrations were assayed from waking saliva samples collected daily over the course of a menstrual cycle. Cycles were aligned on day 0, the day of ovulation. Mean periovulatory estradiol (days -7 to +6) and luteal progesterone (day +2 to +10) indices were calculated. Marital status and motherhood (including age of youngest child) were reported in baseline questionnaires. Multivariable linear regression models were used to examine associations between ovarian hormones, marital status, and motherhood.

RESULTS

Women who were married or living as married had higher estradiol than unmarried women (β = 0.19; 95% CI: 0.02, 0.36) and higher luteal progesterone as well (β = 0.19; 95% CI: -0.01, 0.39). There were no notable differences in hormone levels in relationship to motherhood status.

CONCLUSIONS

Our results indicate that ovarian steroid hormones may be higher among women who are married or living as married, and suggest several possible explanations, however, additional research is needed to elucidate any causal relationships.

Gene variations in oestrogen pathways, CYP19A1, daily 17β-estradiol and mammographic density phenotypes in premenopausal women

INTRODUCTION

High mammographic density is an established breast cancer risk factor, and circulating oestrogen influences oestrogen-regulating gene expression in breast cancer development. However, less is known about the interrelationships of common variants in the CYP19A1 gene, daily levels of oestrogens, mammographic density phenotypes and body mass index (BMI) in premenopausal women.

METHODS

Based on plausible biological mechanisms related to the oestrogen pathway, we investigated the association of single nucleotide polymorphisms (SNPs) in CYP19A1, 17β-estradiol and mammographic density in 202 premenopausal women. DNA was genotyped using the Illumina Golden Gate platform. Daily salivary 17β-estradiol concentrations were measured throughout an entire menstrual cycle. Mammographic density phenotypes were assessed using a computer-assisted method (Madena). We determined associations using multivariable linear and logistic regression models.

RESULTS

The minor alleles of rs749292 were positively (P = 0.026), and the minor alleles of rs7172156 were inversely (P = 0.002) associated with daily 17β-estradiol. We observed an 87% lower level of daily 17β-estradiol throughout a menstrual cycle in heavier women (BMI >23.6 kg/m(2)) of rs7172156 with minor genotype aa compared with major genotype AA. Furthermore, the rs749292 minor alleles were inversely associated with absolute mammographic density (P = 0.032). Lean women with rs749292 minor alleles had 70 to 80% lower risk for high absolute mammographic density (>32.4 cm(2)); Aa: odds ratio (OR) = 0.23 (95% CI 0.07 to 0.75). Lean women with rs7172156 minor homozygous genotype had OR 5.45 for high absolute mammographic density (aa: OR = 5.45 (95% CI 1.13 to 26.3)).

CONCLUSION

Our findings suggest that two SNPs in CYP19A1, rs749292 and rs7172156, are associated with both daily oestrogen levels and mammographic density phenotypes. BMI may modify these associations, but larger studies are needed.

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/m2, 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 (&gt; 23.6 kg/m2), and higher than median percent mammographic density (&gt; 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(&gt; 1.51 mmol/l), lower BMI (≤ 23.6 kg/m2) 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 (AUCe, 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 (AUCp, 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

Abstract P3-01-01: Insulin, Insulin-like Growth Factor-1 and cycling estrogen predict premenopausal mammographic density

Background: Mammographic density, a strong biomarker for breast cancer risk, represents epithelial and stromal proliferation. Insulin and insulin-like growth factor (IGF)-1 are suggested to influence cellular proliferation, while estrogen is a key factor in breast cancer development. However, whether the effects of these hormones among premenopausal women are mediated through mammographic density is less known.

Material and Methods: Fasting serum insulin, IGF-1, and IGF binding protein (IGFBP)-3 were assessed among 202 healthy premenopausal women (Norwegian Energy Balance and Breast cancer Aspects study-I (EBBA-I). Daily salivary levels of 17β-estradiol throughout an entire menstrual cycle were measured at the reproductive Ecology Laboratory, Harvard University, USA. Computer-assisted mammographic density (Madena) was obtained from digitized mammograms taken at day 7–12 of the menstrual cycle. Uni- and multivariable regression models were used to study the associations between hormones and premenopausal percent mammographic density.

Results: Among women with a mean age of 30,7 years, a mean premenopausal percent mammographic density of 29.8 % was observed. Throughout the menstrual cycle when comparing women with a high percent mammographic density (≥28.5%) to women with a low percent mammographic density (&lt;28.5%), we observed insulin, IGF-1 and IGFBP-3 independently and in combination with cycling 17β-estradiol to predict premenopausal percent mammographic density. We observed among women with either serum insulin ≥89 pmol/, IGF-1 ≥24 nmol/l, IGFBP-3 ≥ 100 nmol/l, having a high (≥28.5%) versus a low (&lt;28.5%) percent mammographic density was associated with an increase in overall average 17β-estradiol of 4.0 %, 10.9 % and 14.9%, respectively. Moreover, we observed a higher adjusted Odds Ratio (OR) for having a high percent mammographic density for each standard deviation (SD) increase in overall average 17β -estradiol, insulin, IGF-1 and IGFBP-3: 17β-estradiol, 1.55 (1.06–2.27); insulin, 1.62 (0.76–3.48), IGF-1, 1.90 (1.10–3.27); IGFBP-3, 1.88 (1.05–3.37) (adjusted for age, body mass index-BMI kg/m2)).

Conclusion: Our study supports that insulin, IGF-1 and IGFBP-3 independently, and in combination with cycling estrogen, predicts premenopausal mammographic density. These hormones may be important biomarkers in breast cancer control and clinical practice.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-01-01.

[Musculoskeletal disease and sick-leave]

BACKGROUND

Complaints due to the musculoskeletal system comprise the largest group of diagnoses associated with annual sick payment. We have studied how musculoskeletal complaints predict prolonged sick-leave in a normal population in general and after adjusting for individual confounding factors in the age-group from 40 to 50 years.

MATERIAL AND METHODS

The study is based on information from 14 058 women and men aged 40 - 45 years, who participated in the Hordaland Health Study (HUSK) 1997 - 1999. Follow-up data were retrieved from the Norwegian Social Science Data Services on sick- leave from 6 months after the health examination until the end of 2004. A cumulative sick-leave of more than 40 days was considered high.

RESULTS

41 % of the respondents had musculoskeletal complaints for at least 3 months before the health assessment. The following groups had the highest risk of musculoskeletal complaints and subsequent high sick-leave: women in general and persons with little education, psychiatric complaints, low self-reported health and those who do not exercise strenuously on a regular basis. After adjustment for individual factors (sex, education, psychiatric complaints and self-reported health), persons who had suffered from long-standing pain or stiffness had an almost doubled (OR 1.9, 95 % CI 1.7 - 2.0) risk of later high sick-leave. Widespread pain increased the risk for sick-leave even more.

INTERPRETATION

Musculoskeletal complaints are an independent predictor for future sick-leave.