Two fully automated data-driven 3D whole-breast segmentation strategies in MRI for MR-based breast density using image registration and U-Net with a focus on reproducibility

Presence of higher breast density (BD) and persistence over time are risk factors for breast cancer. A quantitatively accurate and highly reproducible BD measure that relies on precise and reproducible whole-breast segmentation is desirable. In this study, we aimed to develop a highly reproducible and accurate whole-breast segmentation algorithm for the generation of reproducible BD measures. Three datasets of volunteers from two clinical trials were included. Breast MR images were acquired on 3 T Siemens Biograph mMR, Prisma, and Skyra using 3D Cartesian six-echo GRE sequences with a fat-water separation technique. Two whole-breast segmentation strategies, utilizing image registration and 3D U-Net, were developed. Manual segmentation was performed. A task-based analysis was performed: a previously developed MR-based BD measure, MagDensity, was calculated and assessed using automated and manual segmentation. The mean squared error (MSE) and intraclass correlation coefficient (ICC) between MagDensity were evaluated using the manual segmentation as a reference. The test-retest reproducibility of MagDensity derived from different breast segmentation methods was assessed using the difference between the test and retest measures (Δ_2-1), MSE, and ICC. The results showed that MagDensity derived by the registration and deep learning segmentation methods exhibited high concordance with manual segmentation, with ICCs of 0.986 (95%CI: 0.974-0.993) and 0.983 (95%CI: 0.961-0.992), respectively. For test-retest analysis, MagDensity derived using the registration algorithm achieved the smallest MSE of 0.370 and highest ICC of 0.993 (95%CI: 0.982-0.997) when compared to other segmentation methods. In conclusion, the proposed registration and deep learning whole-breast segmentation methods are accurate and reliable for estimating BD. Both methods outperformed a previously developed algorithm and manual segmentation in the test-retest assessment, with the registration exhibiting superior performance for highly reproducible BD measurements.

The Importance of Drug Concentration at the Site of Action: Celecoxib and Colon Polyp Prevention as a Case Study

Celecoxib is among the more potent and better clinically studied, nonsteroidal anti-inflammatory drugs (NSAID) for use as a chemoprevention agent for colorectal cancer. Its use is associated with a 40% to 50% response rate for reduction in adenomatous polyps. However, rare serious cardiovascular effects and even death with celecoxib and other NSAIDs make it important to understand why some patients respond and others do not. Celecoxib is a selective inhibitor of COX-2. Its anticancer mechanism has largely been attributed to the inhibition of COX-2. Celecoxib also shows activity to induce apoptosis in cancer cells not expressing COX-2. This includes activity to upregulate 15-lipoxygenase-1 (15-LOX-1) independent of COX-2 and increase the synthesis of 13-S-hydroxyoctadecadienoic acid (13-S-HODE) from linoleic acid (LA) to downregulate PPAR-δ and induce apoptosis in colorectal cancer models. In examining the effect of celecoxib on 15-LOX-1 for reducing adenomatous polyps in patients with familial adenomatous polyposis (FAP), Yang and colleagues point out the potential importance of drug bioavailability in blood, normal, and neoplastic colorectal tissue in patient response. See related article, p. 217.

Abstract P1-10-05: Evidence that body mass index modifies breast tissue collagen peptide response pattern to treatment with the non-steroidal anti-inflammatory drug sulindac

Background. In observational studies, regular use of non-steroidal anti-inflammatory drugs (NSAIDs) is associated with reduced breast cancer risk and disease recurrence with evidence that the benefit is greater in overweight/obese women. This parallels findings that obesity is associated with an increase in proinflammatory processes with possible effects on the breast stroma and extracellular matrix. Methods. To assess if body mass index (BMI kg/m2) alters breast tissue response to NSAIDs, we conducted exploratory analyses of change in breast tissue collagen-associated peptides following 6 months of treatment with the NSAID sulindac (150 mg bid) by BMI category: normal (18.5-24.9 n=6), overweight (25-29.9 n=14) and obese (≥30 n=11). Samples for this study were non-cancer core needle breast biopsies from postmenopausal women with a history of hormone receptor positive breast cancer enrolled to study sulindac effect on breast tissue biomarkers. At completion, 36 of 50 patients underwent baseline biopsy and 31 had sufficient tissue for paired analyses. Tissue collagen-associated peptides were studied using whole slide tissue imaging mass spectrometry proteomics. Individual peptide signals were normalized to total ion current and mean peak intensity per area across the entire biological specimen were used to generate a score per patient. Change in stroma peptides was evaluated by BMI status using the Wilcoxon matched pairs signed rank test. Unsupervised hierarchical clustering and heatmap visualization were used to assess differential expression of the peaks. Results. Approximately, 550 peptide peaks were found by targeted collagen tissue imaging proteomics. Striking differences in response to sulindac were observed by BMI. In overweight patients, 6 peptides related to COL1A1, COL6A1, COL6A3 and VIM on database matching differed significantly before and after sulindac treatment. Three were also altered in obese women. Two of the peptides overlapped 10 peptide changes identified in unstratified analyses reported in a separate submitted abstract on the main effect of sulindac on tissue collagen. Interestingly, these peptides were not altered in patients with normal BMI. In addition, on study 15 patients experienced a decrease in BMI and 12 experienced an increase. Two collagen peptides showed inverse relationships dependent on change in BMI status during the study. Conclusion. Six-month treatment with the non-selective NSAID sulindac was associated with changes in collagen-associated peptide differently by BMI status and by weight change. Our findings are most consistent with changes in post-translational hydroxylated proline modifications of collagen variation in the triple helical region. Ongoing work may provide insights on inflammation/adiposity-associated inflammation and effects on breast tissue collagen.

Citation Format: Denys Rujchanarong, Peggi M. Angel, Alison Stopeck, Christina Preece, Pavani Chalasani, Patricia A. Thompson. Evidence that body mass index modifies breast tissue collagen peptide response pattern to treatment with the non-steroidal anti-inflammatory drug sulindac [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 P1-10-05.

Sulindac Improves Stiffness and Quality of Life in Women Taking Aromatase Inhibitors for Breast Cancer

PURPOSE

To examine benefit of sulindac for relief of musculoskeletal symptoms (MSS) in patients stable on aromatase inhibitors (AIs).

METHODS

Sulindac was evaluated at 150 mg twice daily for effects on MSS at 3, 6, 9, and 12 months in 50 postmenopausal women stable on AI therapy for a median of 12.5 months for hormone receptor-positive breast cancer. A separate, non-randomized group of 50 similar patients was observed for change in MSS over 12 months. MSS severity was assessed using the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) Index and Brief Pain Inventory Short Form (BPI-SF). The Functional Assessment of Cancer Therapy-General form (FACT-G) measured quality of life (QOL). Change in MSS and QOL across time was assessed in each group using linear mixed effects models.

RESULTS

Stiffness, not pain, was the main complaint at baseline. At 12 months, sulindac patients reported decreases (improvements) in mean (95% CI) Total WOMAC score [- 5.85 (- 9.73, - 1.96)] and WOMAC pain [- 5.40 (- 10.64, - 0 .18)], Stiffness [- 9.53 (- 14.98, - 4.08)] and Physical Function [- 5.61 (- 9.62, - 1.60)] subscales, but not BPI-SF worst pain. Among sulindac patients with higher baseline MSS severity, 35% experienced ≥ 50% improvement in Total WOMAC and Total FACT-G scores [6.18 (2.08, 10.27); P = 0.003]. For the observation group, MSS and QOL did not improve over 12 months, even among those with higher baseline MSS severity.

CONCLUSIONS

Sulindac may relieve MSS in AI patients, especially physical function and stiffness. Randomized controlled trials should further evaluate NSAIDs on AI-MSS and AI adherence.

TRIAL REGISTRATION NUMBER AND DATE OF REGISTRATION

NCT01761877, December, 2012.

Sulindac, a Nonselective NSAID, Reduces Breast Density in Postmenopausal Women with Breast Cancer Treated with Aromatase Inhibitors

PURPOSE

To evaluate the effect of sulindac, a nonselective anti-inflammatory drug (NSAID), for activity to reduce breast density (BD), a risk factor for breast cancer.

EXPERIMENTAL DESIGN

An open-label phase II study was conducted to test the effect of 12 months' daily sulindac at 150 mg twice daily on change in percent BD in postmenopausal hormone receptor-positive breast cancer patients on aromatase inhibitor (AI) therapy. Change in percent BD in the contralateral, unaffected breast was measured by noncontrast magnetic resonance imaging (MRI) and reported as change in MRI percent BD (MRPD). A nonrandomized patient population on AI therapy (observation group) with comparable baseline BD was also followed for 12 months. Changes in tissue collagen after 6 months of sulindac treatment were explored using second-harmonic generated microscopy in a subset of women in the sulindac group who agreed to repeat breast biopsy.

RESULTS

In 43 women who completed 1 year of sulindac (86% of those accrued), relative MRPD significantly decreased by 9.8% [95% confidence interval (CI), -14.6 to -4.7] at 12 months, an absolute decrease of -1.4% (95% CI, -2.5 to -0.3). A significant decrease in mean breast tissue collagen fiber straightness (P = 0.032), an investigational biomarker of tissue inflammation, was also observed. MRPD (relative or absolute) did not change in the AI-only observation group (N = 40).

CONCLUSIONS

This is the first study to indicate that the NSAID sulindac may reduce BD. Additional studies are needed to verify these findings and determine if prostaglandin E₂ inhibition by NSAIDs is important for BD or collagen modulation.

Investigating the effects of handedness on the consistency of lateralization for speech production and semantic processing tasks using functional transcranial Doppler sonography

The left hemisphere is dominant for language in most people, but lateralization strength varies between different tasks and individuals. A large body of literature has shown that handedness is associated with lateralization: left handers have weaker language lateralization on average, and a greater incidence of atypical (right hemisphere) lateralization; but typically, these studies have relied on a single measure of language lateralization. Here we consider the relationships between lateralization for two different language tasks. We investigated the influence of handedness on lateralization using functional transcranial Doppler sonography (fTCD), using an existing dataset (N = 151 adults, 21 left handed). We compared a speech production task (word generation) and a semantic association task. We demonstrated stronger left-lateralization for word generation than semantic association; and a moderate correlation between laterality indices for the two tasks (r = 0.59). Laterality indices were stronger for right than left handers, and left handers were more likely than right handers to have atypical (right hemisphere) lateralization or inconsistent lateralization between the two tasks. These results add to our knowledge of individual differences in lateralization and support the view that language lateralization is multifactorial rather than unitary.

Oxylipins Correlate with Quality of Life in Women Taking Aromatase Inhibitors for Breast Cancer

The purpose of this study was to determine if oxylipins – oxygenated bioactive lipid metabolites of ω-3 and ω-6 fatty acids with varying roles in inflammation and pain – correlate with aromatase inhibitor-associated arthralgia (AIA) and quality of life (QOL) in early stage breast cancer (ESBC) patients. Methods: ESBC patients on AI therapy were enrolled to an open-label study of sulindac, a non-steroidal anti-inflammatory drug (NSAID), for 12 months (n = 47). Pre-intervention arthralgia and physical function were assessed using the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) questionnaire, where higher scores indicate worse symptoms. The Functional Assessment of Cancer Therapy – General (FACT-G) questionnaire was used to assess QOL, where higher scores indicate better QOL. A total of 53 plasma oxylipins in plasma were quantified by mass spectrometry. Pearson's correlation was used to measure the association between pre-intervention oxylipin concentrations, arthralgias and QOL. Results: Prior to initiating sulindac, baseline levels of 17 oxylipins were found to be significantly correlated with QOL scales. This included inverse associations between QOL and seven pro-inflammatory products of ω-6 fatty acid metabolism. Notably, prostaglandin E2, the primary target of NSAIDs, was negatively correlated with Social Well-Being (rho = −0.30; P = 0.04). Conversely, resolvin D1, a potent anti-inflammatory lipid, was positively associated with Total FACT-G (rho = 0.31; P = 0.03) and Emotional Well-Being (rho = 0.37; P = 0.01). Two ω-3 metabolites with unknown mechanisms were correlated with both QOL and WOMAC; 19,20-DiHDPE was positively correlated with Total (rho = 0.34; P = 0.02) and Social FACT-G (rho = 0.32; P = 0.03), and inversely with Total WOMAC (rho = -0.303; P = 0.04) and Stiffness (rho = −0.32; P = 0.03); and 5(6)-DiHETE was inversely correlated with Social FACT-G (rho = −0.33; P = 0.02) and positively with Total WOMAC (rho = 0.31; P = 0.04). Conclusions: This is the first evidence that plasma oxylipin metabolites of ω-3/ω-6 fatty acids correlate with QOL and arthralgia symptoms in patients on AIs and suggests oxylipins as a potential novel target for improving QOL and adherence to AI therapy in patients with ESBC.

Abstract P5-12-11: M2 macrophages increase after neoadjuvant HER2 targeted chemotherapy

Purpose: Recent observations suggest a positive association between the presence of tumor-associated myeloid and lymphoid immune cells and clinical responses to HER2 therapies. The specific immune cell composition of HER2+ tumors and the effects of therapy on the tumor immune microenvironment remains poorly understood; limiting efforts to effectively direct immunomodulatory agents in HER2+ breast cancer. We sought to assess the feasibility of a multiplex immunofluorescence strategy to characterize the immune milieu of HER2+ tumors, pre and post treatment. Methods: We conducted a feasibility study using the Perkin Elmer OPAL multiplex dye chemistry for immunofluorescence of tumor, myeloid, and lymphoid cells in pretreatment biopsy and surgical resection tissues of 11 patients who received neoadjuvant HER2 antibody with chemotherapy. Two panels of up to 6 antibodies were studied including a predominantly myeloid panel targeting CD80, CD68, CD163, CD206, PD-L1, and cytokeratin; and a 'lymphoid/proliferation' panel targeting FoxP3, cytokeratin, Granzyme B, CD4, CD8, and Ki67. For paired samples, analysis of pre/post differences were analyzed using two tailed, t-test. Results: 100% of the pre-treatment biopsy samples yielded high quality immune and tumor cell immunofluorescence profiles for both panels. In contrast, post treatment specimens were more challenging. For the post treatment tissues, ˜25% of specimens failed to yield results in at least one panel. As shown in Table 1, the %CD206+ M2 type macrophage population increased between pre and post treatment (p=0.012). This was reflected in a decrease in the M1:M2 ratio and variability in the ratio in favor of M2 (median 0.34 [IQR = 1.01] to 0.11 [IQR=0.10], p=0.0003). In the lymphoid panel, we observed a non-significant reduction in % FoxP3+CD4 T cells with less variability between patients post treatment and a significant decrease in total CD8+ T cells. Further, there was a significant reduction in %Granzyme B positive T cells (median 6.63 to <1%, p=0.02) and non-significant decrease in proliferating (Ki67+) T cells post treatment. PD-L1 expression was low in both pre and post specimens.

MarkerSampleMinMedianMaxIQR%CD206+ Mono/MacPre1.358.7135.8911.05%CD206+ Mono/MacPost25.438.9777.621.54M1/M2 RatioPre0.110.342.141.01M1/M2 RatioPost0.030.110.210.1%Ki67+ T cellsPre0.137.9220.0411.06%Ki67+ T cellsPost04.5621.836.31%PD-L1+ MyeloidPre01.0512.060.95%PD-L1+ MyeloidPost00.554.261.47%Granzyme B T cellsPre2.926.6333.727.2%Granzyme B T cellsPost00.892.481.73%FoxP3+ CD4 +Pre01.6456.0416.44%FoxP3+ CD4 +Post01.166.824.14#Total CD8+ T cellsPre5788,36635,42615,744#Total CD8+ T cellsPost121,3717,9043,658

Conclusions: Multiplex immune profiling is a practical approach to characterize the tumor immune microenvironment in biopsy and post treatment specimens. Neoadjuvant HER2 targeted chemotherapy significantly shifts the myeloid population to an M2 (immunosuppressive) phenotype with evidence for a reduction in the number of Ki67 and Granzyme B+ T cells. These preliminary results suggest immunomodulatory agents that are able to induce or maintain an M1 polarized tumor microenvironment may have utility to enhance long term anti-tumor immunity in HER2 disease.

Citation Format: Thompson PA, Uhlik M, Preece C, Gorden K, Harrison B, Graff J, Stopeck A. M2 macrophages increase after neoadjuvant HER2 targeted chemotherapy [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 P5-12-11.

Abstract P2-07-06: Cumulative copy number imbalances after neoadjuvant chemotherapy residual breast tumor is an independent predictor of relapse

Background: Identifying breast cancer patients after neoadjuvant chemotherapy (NAC) at greatest risk of recurrence would enhance selection of patients who may benefit from novel adjuvant treatments.

Patients. 243 stage I-III breast cancer patients who underwent NAC with ≥10% residual tumor cellularity were identified from the MD Anderson Cancer Center and Ben Taub General Hospital, Harris County hospital. Tumor DNA was isolated for DNA copy number using OncoScan CNV FFPE, Affymetrix. Median follow-up was 67.8 months. Continuous residual cancer burden (RCB) scores with CNI data were available for 152 cases. To test if CNIs covering large regions were associated with recurrence after adjusting for prognostic variables and study site, data were summed to a chromosome-arm level. Eleven chromosome arms with false discovery rate <0.05 for breast cancer recurrence were identified. A stepwise multivariable model including age at diagnosis, tumor subtype, histologic grade, pre- and post-treatment stage, study site, and the 11 chromosomal arms were used to fit a parsimonious multivariate model for recurrence. Minimizing the Akaike Information Criterion yielded a final model with post-stage and a 5-arm CNI (5A-CNI) indicator including 2q, 3q, 4q, 10p, and 18p. Tumors were classified on 5A-CNI as 0 [no CNI], 1 [1- 2] and 2 [> 2].

Results. The study population included 76 non-Hispanic White, 89 Hispanic, and 68 African American patients with a mean age of 49.1 years. 105 patients were classified as 5A-CNI-0, 97 as 5A-CNI-1 and 41 as 5A-CNI-2. A higher 5A-CNI score was associated with tumor grade, ER-negative tumors (p<0.002) and tumor subtype (p=0.014). For 5A-CNI scores of 0, 1 and 2, recurrence rates of 14%, 34% and 58.5% were observed, respectively. In the final multivariable model adjusted for post-stage, RCB and study site, when compared to 5A-CNI-0, the hazard of recurrence was elevated for 5A-CNI-1 (HR= 2.27 [95% CI, 1.01-5.1]) and 5A-CNI-2 tumors (HR=7.43 [95% CI, 2.85-19.39]). Further, while the sample size is limiting, of 10 patients who were RCB3 and 5A-CNI-2, 9 relapsed (90%) during follow-up compared to only 6 of 43 (14%) of RCB3 patients with 5A-CNI-0 (p<10-6). For patients with RCB1 or 2, relapse did not differ by 5A-CNI score. Neither race nor ethnicity were found to be independently associated with recurrence or tumor subtype. However, African American, followed by Hispanic patients, were more likely than non-Hispanic White patients to be classified as 5A-CNI-2 (p=0.013).

Table 1.Significant difference in distribution of 5 arm CNI classifier by Race/Ethnicity in Study Sample (p =0.013).5A-CNI012Non-Hispanic Whiten=44; 57.9%n=25; 32.9%n=7; 9.2%Hispanicn=32; 36%n=42; 47.2%n=15; 16.9%African Americann=28; 41.2%n=23; 33.8%n=17; 25%

Conclusion. The 5A-CNI score in post NAC tumor identifies a patient population with very poor prognosis independent of current clinical prognostic factors including RCB. Validation of these findings may lead to a post NAC genomic test that identifies patients who would benefit from additional treatment Further investigation of the nature of the association between the 5A-CNI score and race/ethnicity, which appears independent of tumor subtype, is warranted.

Citation Format: Thompson PA, Brewster A, Tsavachidis S, Armstrong G, Do K-A, Ha M-J, Gutierrez C, Symmans F, Bondy M. Cumulative copy number imbalances after neoadjuvant chemotherapy residual breast tumor is an independent predictor of relapse [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 P2-07-06.

Effects of ursodeoxycholic acid on the gut microbiome and colorectal adenoma development

It has been previously reported that ursodeoxycholic acid (UDCA), a therapeutic bile acid, reduced risk for advanced colorectal adenoma in men but not women. Interactions between the gut microbiome and fecal bile acid composition as a factor in colorectal cancer neoplasia have been postulated but evidence is limited to small cohorts and animal studies. Using banked stool samples collected as part of a phase III randomized clinical trial of UDCA for the prevention of colorectal adenomatous polyps, we compared change in the microbiome composition after a 3-year intervention in a subset of participants randomized to oral UDCA at 8-10 mg/kg of body weight per day (n = 198) or placebo (n = 203). Study participants randomized to UDCA experienced compositional changes in their microbiome that were statistically more similar to other individuals in the UDCA arm than to those in the placebo arm. This reflected a UDCA-associated shift in microbial community composition (P < 0.001), independent of sex, with no evidence of a UDCA effect on microbial richness (P > 0.05). These UDCA-associated shifts in microbial community distance metrics from baseline to end-of-study were not associated with risk of any or advanced adenoma (all P > 0.05) in men or women. Separate analyses of microbial networks revealed an overrepresentation of Faecalibacterium prausnitzii in the post-UDCA arm and an inverse relationship between F prausnitzii and Ruminococcus gnavus. In men who received UDCA, the overrepresentation of F prausnitzii and underrepresentation of R gnavus were more prominent in those with no adenoma recurrence at follow-up compared to men with recurrence. This relationship was not observed in women. Daily UDCA use modestly influences the relative abundance of microbial species in stool and affects the microbial network composition with suggestive evidence for sex-specific effects of UDCA on stool microbial community composition as a modifier of colorectal adenoma risk.

Selenium supplementation and insulin resistance in a randomized, clinical trial

OBJECTIVE

While controversial, observational and randomized clinical trial data implicate the micronutrient selenium (Se) in the development of type 2 diabetes (T2D). The aim of this study was to test the hypothesis that Se supplementation adversely affects pancreatic β-cell function and insulin sensitivity.

RESEARCH DESIGN AND METHODS

In a subset of 400 individuals participating in a randomized, placebo-controlled trial of Se at 200 µg/day for colorectal adenomatous polyps, fasting plasma glucose and insulin were measured before randomization and within 6 months of completing intervention. Change in the homeostasis model assessment-β cell function (HOMA2-%β) and insulin sensitivity (HOMA2-%S) were compared between arms. A subgroup of 175 (79 Se and 96 placebo) participants underwent a modified oral glucose tolerance test (mOGTT) at the end of intervention and change in glucose values was assessed.

RESULTS

No statistically significant differences were observed for changes in HOMA2-%β or HOMA2-%S between those who received Se compared with placebo. After a mean of 2.9 years on study, mean HOMA2-%β values were 3.1±24.0 and 3.1±29.8 for the Se and placebo groups, respectively (p=0.99). For HOMA2-%S, the values were -0.5±223.2 and 80.9±1530.9 for the Se and placebo groups, respectively (p=1.00). Stratification by sex or age did not reveal any statistically significant effects on insulin sensitivity by treatment group. For mOGTT, mean baseline fasting blood glucose concentrations were significantly higher among participants in the placebo group compared with the Se group (96.6±14.6 and 92.3±12.0, respectively; p=0.04), a trend which remained through the 20 min assessment.

CONCLUSIONS

These findings do not support a significant adverse effect of daily Se supplementation with 200 µg/day of selenized yeast on β-cell function or insulin sensitivity as an explanation for previously reported associations between Se and T2D. Further clarification of longer term effects of Se is needed.

CLINICAL TRIAL REGISTRY

NIH Clinical Trials.gov number NCT00078897.

Impact of acculturation on breast cancer treatment and survivorship care among Mexican American patients in Texas

PURPOSE

Given the increasing number and diversity of cancer survivors in the USA and persistent racial/ethnic disparities in breast cancer care, we sought to examine the role of acculturation in adherence to recommended surgical treatment and survivorship care recommendations.

METHODS

Study participants included 343 Mexican American women with stage I to III breast cancer who participated in the Ella Binational Breast Cancer Study and were treated at The University of Texas MD Anderson Cancer Center in Houston, Texas, between March 2007 and June 2011. Participants completed a questionnaire measuring acculturation, and clinical and demographic variables were obtained from an institutional database. Multivariable logistic regression models were constructed to examine differences in surgical procedures received and adherence to long-term survivorship care by acculturation level.

RESULTS

Bilingual (odds ratio [OR] = 1.85; 95% confidence interval [CI] = 0.85-4.02, P = .11) and English-dominant women (OR = 2.39; 95% CI = 1.02-5.61, P = .04) were more likely to receive breast-conserving surgery (versus mastectomy) than were Spanish-dominant women. Among all patients, adherence to surveillance mammography and clinic visits decreased over time; the decline in clinic visit adherence was statistically significant (P = .005). Although no statistically significant association was found between acculturation and adherence to long-term survivorship care, receipt of breast-conserving surgery (versus mastectomy) was significantly associated with higher adherence to surveillance mammograms.

CONCLUSION

Acculturation may play a role in decision-making about surgical management of breast cancer, and further studies with larger samples are needed to explore its role in adherence to survivorship care recommendations. Findings from this study may help identify patients requiring additional support while making decisions pertaining to their cancer treatment and survivorship care.

Celecoxib use and circulating oxylipins in a colon polyp prevention trial

Drugs that inhibit cyclooxygenase (COX)-2 and the metabolism of arachidonic acid (ARA) to prostaglandin E2 are potent anti-inflammatory agents used widely in the treatment of joint and muscle pain. Despite their benefits, daily use of these drugs has been associated with hypertension, cardiovascular and gastrointestinal toxicities. It is now recognized that ARA is metabolized to a number of bioactive oxygenated lipids (oxylipins) by cyclooxygenase (COX), lipoxygenase (LOX), and cytochrome P450 (CYP450) enzymes. Currently, the contribution of individual variability in ARA metabolism in response to the COX-2 inhibitors and potential adverse effects remains poorly understood. Using patient samples from the randomized, placebo-controlled phase III selenium/celecoxib (Sel/Cel) trial for the prevention of colorectal adenomatous polyps, we analyzed plasma concentrations of 74 oxylipins in a subset of participants who received celecoxib (n = 90) or placebo (n = 95). We assessed the effect of celecoxib (with and without low dose aspirin) on circulating oxylipins and systolic blood pressure (SBP). Individual CYP450- and LOX- but not COX-derived metabolites were higher with celecoxib than placebo (P<0.05) and differences were greater among non-aspirin users. LOX derived 5- and 8-HETE were elevated with celecoxib and positively associated with systolic blood pressure (P = 0.011 and P = 0.019 respectively). 20-HETE, a prohypertensive androgen-sensitive CYP450 metabolite was higher with celecoxib absent aspirin and was positively associated with SBP in men (P = 0.040) but not women. Independent of celecoxib or aspirin, LOX derived metabolites from ARA were strongly associated with SBP including 5- and 8-HETE. These findings support oxylipins, particularly the ARA LOX-derived, in blood pressure control and indicate that pharmacologic inhibition of COX-2 has effects on LOX and CYP450 ARA metabolism that contribute to hypertension in some patients.

Reproducible automated breast density measure with no ionizing radiation using fat-water decomposition MRI

BACKGROUND

Increased breast density is a significant independent risk factor for breast cancer, and recent studies show that this risk is modifiable. Hence, breast density measures sensitive to small changes are desired.

PURPOSE

Utilizing fat-water decomposition MRI, we propose an automated, reproducible breast density measurement, which is nonionizing and directly comparable to mammographic density (MD).

STUDY TYPE

Retrospective study.

POPULATION

The study included two sample sets of breast cancer patients enrolled in a clinical trial, for concordance analysis with MD (40 patients) and reproducibility analysis (10 patients).

FIELD STRENGTH/SEQUENCE

The majority of MRI scans (59 scans) were performed with a 1.5T GE Signa scanner using radial IDEAL-GRASE sequence, while the remaining (seven scans) were performed with a 3T Siemens Skyra using 3D Cartesian 6-echo GRE sequence with a similar fat-water separation technique.

ASSESSMENT

After automated breast segmentation, breast density was calculated using FraGW, a new measure developed to reliably reflect the amount of fibroglandular tissue and total water content in the entire breast. Based on its concordance with MD, FraGW was calibrated to MR-based breast density (MRD) to be comparable to MD. A previous breast density measurement, Fra80-the ratio of breast voxels with <80% fat fraction-was also calculated for comparison with FraGW.

STATISTICAL TESTS

Pearson correlation was performed between MD (reference standard) and FraGW (and Fra80). Test-retest reproducibility of MRD was evaluated using the difference between test-retest measures (Δ_1-2 ) and intraclass correlation coefficient (ICC).

RESULTS

Both FraGW and Fra80 were strongly correlated with MD (Pearson ρ: 0.96 vs. 0.90, both P < 0.0001). MRD converted from FraGW showed higher test-retest reproducibility (Δ_1-2 variation: 1.1% ± 1.2%; ICC: 0.99) compared to MD itself (literature intrareader ICC ≤0.96) and Fra80.

DATA CONCLUSION

The proposed MRD is directly comparable with MD and highly reproducible, which enables the early detection of small breast density changes and treatment response.

LEVEL OF EVIDENCE

3 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;48:971-981.

Characteristics, outcomes, prognostic factors and treatment of patients with T-cell prolymphocytic leukemia (T-PLL)

Background

T-cell prolymphocytic leukemia (T-PLL) is a rare and aggressive disease. In this study, we report our experience from 119 patients with T-PLL.

Patients and methods

We reviewed the clinico-pathologic records of 119 consecutive patients with T-PLL, who presented to our institution between 1990 and 2016.

Results

One hundred and nineteen patients with T-PLL were analysed. Complex karyotype and aberrations in chromosome 14 were seen in 65% and 52% patients, respectively. Seventy-five patients (63%) were previously untreated and 43 (37%) were initially treated outside our institution. Sixty-three previously untreated patients (84%) received frontline therapies. Overall, 95 patients (80%) have died. Median overall survival (OS) from diagnosis was 19 months [95% confidence interval (CI) 16-26 months]. Using recursive partitioning (RP), we found that patients with hemoglobin < 9.3 g/dl, lactate dehydrogenase (LDH) ≥ 1668 IU/l, white blood cell  ≥ 208 K/l and β2M ≥ 8 mg/l had significantly inferior OS and patients with hemoglobin < 9.3 g/dl had inferior progression-free survival (PFS). In multivariate analysis, we identified that presence of pleural effusion [hazard ratio (HR) 2.08 (95% CI 1.11-3.9); P = 0.02], high LDH (≥ 1668 IU/l) [HR 2.5 (95% CI 1.20-4.24); P < 0.001)], and low hemoglobin (< 9.3 g/dl) [HR 0.33 (95% CI 0.14-0.75); P = 0.008] were associated with shorter OS. Fifty-five previously untreated patients received treatment with an alemtuzumab-based regimen (42 monotherapy and 13 combination with pentostatin). Overall response rate, complete remission rate (CR) for single-agent alemtuzumab and alemtuzumab combined with pentostatin were 83%, 66% and 82%, 73% respectively. In patients who achieved initial CR, stem cell transplantation was not associated with longer PFS and OS.

Conclusion

Outcomes in T-PLL remain poor. Multicenter collaborative effort is required to conduct prospective studies.

Ibrutinib modulates the immunosuppressive CLL microenvironment through STAT3-mediated suppression of regulatory B-cell function and inhibition of the PD-1/PD-L1 pathway

Ibrutinib, a covalent inhibitor of Bruton Tyrosine Kinase (BTK), is approved for treatment of patients with relapsed/refractory or treatment-naïve chronic lymphocytic leukemia (CLL). Besides directly inhibiting BTK, ibrutinib possesses immunomodulatory properties through targeting multiple signaling pathways. Understanding how this ancillary property of ibrutinib modifies the CLL microenvironment is crucial for further exploration of immune responses in this disease and devising future combination therapies. Here, we investigated the mechanisms underlying the immunomodulatory properties of ibrutinib. In peripheral blood samples collected prospectively from CLL patients treated with ibrutinib monotherapy, we observed selective and durable downregulation of PD-L1 on CLL cells by 3 months post-treatment. Further analysis showed that this effect was mediated through inhibition of the constitutively active signal transducer and activator of transcription 3 (STAT3) in CLL cells. Similar downregulation of PD-1 was observed in CD4+ and CD8+ T cells. We also demonstrated reduced interleukin (IL)-10 production by CLL cells in patients receiving ibrutinib, which was also linked to suppression of STAT3 phosphorylation. Taken together, these findings provide a mechanistic basis for immunomodulation by ibrutinib through inhibition of the STAT3 pathway, critical in inducing and sustaining tumor immune tolerance. The data also merit testing of combination treatments combining ibrutinib with agents capable of augmenting its immunomodulatory effects.

A randomized, placebo-controlled trial of diindolylmethane for breast cancer biomarker modulation in patients taking tamoxifen

PURPOSE

Diindolylmethane (DIM), a bioactive metabolite of indole-3-carbinol found in cruciferous vegetables, has proposed cancer chemoprevention activity in the breast. There is limited evidence of clinically relevant activity of DIM or long-term safety data of its regular use. A randomized, double-blind, placebo-controlled trial was conducted to determine the activity and safety of combined use of BioResponse DIM® (BR-DIM) with tamoxifen.

METHODS

Women prescribed tamoxifen (n = 130) were randomly assigned oral BR-DIM at 150 mg twice daily or placebo, for 12 months. The primary study endpoint was change in urinary 2/16α-hydroxyestrone (2/16α-OHE1) ratio. Changes in 4-hydroxyestrone (4-OHE1), serum estrogens, sex hormone-binding globulin (SHBG), breast density, and tamoxifen metabolites were assessed.

RESULTS

Ninety-eight women (51 placebo, 47 DIM) completed intervention; compliance with treatment was >91%. BR-DIM increased the 2/16α-OHE1 ratio (+3.2 [0.8, 8.4]) compared to placebo (-0.7 [-1.7, 0.8], P < 0.001). Serum SHBG increased with BR-DIM compared to placebo (+25 ± 22 and +1.1 ± 19 nmol/L, respectively). No change in breast density measured by mammography or by MRI was observed. Plasma tamoxifen metabolites (endoxifen, 4-OH tamoxifen, and N-desmethyl-tamoxifen) were reduced in women receiving BR-DIM versus placebo (P < 0.001). Minimal adverse events were reported and did not differ by treatment arm.

CONCLUSION

In patients taking tamoxifen for breast cancer, daily BR-DIM promoted favorable changes in estrogen metabolism and circulating levels of SHBG. Further research is warranted to determine whether BR-DIM associated decreases in tamoxifen metabolites, including effects on endoxifen levels, attenuates the clinical benefit of tamoxifen.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01391689.

Abstract P6-09-19: Breast density change at 6 months is associated with change at 12 months as measured by fat-water decomposition MRI in women on tamoxifen

Objective: Tamoxifen (TAM) lowers breast cancer recurrence by 40-50% with evidence of individual variability in responsiveness. A ≥10% decrease in mammography-determined breast density (BD) after 12–18 months of TAM use has been associated with clinical benefit. Early determination of changes in BD may offer a strategy to tailor hormone therapy in non-responders; for responders, it may encourage adherence. Fat-water decomposition MRI (FWD-MRI) is an accurate and fast (&lt; 5 minutes) method for measuring BD without ionizing radiation or contrast agent. Here, we examined whether change in FWD-MRI-derived BD predicts decrease in BD at earlier time points than observable with a 12-month measure of BD.

Methods: The study population included a subset of 44 pre- and post-menopausal women receiving TAM for treatment of early-stage breast cancer or prevention who were enrolled in a randomized, placebo-controlled trial of diindolylmethane. Eligibility for this analysis included participants with FWD-MRI scans at baseline, 6 and 12 months. Median time on TAM at baseline was 13 months (IQR, 5–26 months). All MRI images were acquired on a 1.5T GE Signa NV-CV/i scanner. Automated breast segmentation was performed using MATLAB software and validated against manual ROI drawings. MRI-based BD was calculated as the ratio of breast voxels with &lt;80% apparent fat fraction (Fra80) over the entire breast, a measure previously shown by our group to be highly correlated with mammography-derived BD. For 40 participants, the unaffected, contralateral breast was analyzed. For 4 patients with two unaffected breasts, BD data from the left breast were analyzed. Change in BD was conservatively defined as &gt; 2 times the test-retest variability of Fra80 (0.032). McNemar's test was used to test the association between change from baseline to 6 months and change from baseline to 12 months.

Results and Discussion: At 12 months, 15 (34%) participants had a decrease in BD, whereas 29 (66%) remained unchanged or increased. Of these 29, 28 also had no decrease at 6 months (specificity = 97%), and 9 of the 15 women who showed a decrease at 12 months had a decrease at 6 months (sensitivity = 60%; McNemar's test, P = 0.06). Conversely, for those women with a measured decrease in BD from baseline to 6 months, 9 of 10 had a measured decrease at 12 months. A study limitation is inclusion of participants on TAM for varying duration as the greatest change in BD likely would have occurred earlier. Ongoing efforts will focus on FWD-MRI for measures of change in BD in patients initiating TAM.

Conclusion: Use of the specified cut point would fail to detect a decrease in BD at 12 months in 40% of women. However, a decrease in BD from baseline to 6 months was highly associated with decrease from baseline to 12 months and in some women may be useful as an early biomarker of effect. Ongoing effort is needed to determine the impact of factors such as baseline BD, menopausal status, and time on TAM in misclassification of BD change using the 6-month measure.

Acknowledgement: NIH grants CA149417, CA161534.Objective: Tamoxifen (TAM) lowers breast cancer recurrence by 40-50% with evidence of individual variability in responsiveness. A ≥10% decrease in mammography-determined breast density (BD) after 12–18 months of TAM use has been associated with clinical benefit. Early determination of changes in BD may offer a strategy to tailor hormone therapy in non-responders; for responders, it may encourage adherence. Fat-water decomposition MRI (FWD-MRI) is an accurate and fast (&lt; 5 minutes) method for measuring BD without ionizing radiation or contrast agent. Here, we examined whether change in FWD-MRI-derived BD predicts decrease in BD at earlier time points than observable with a 12-month measure of BD.

Methods: The study population included a subset of 44 pre- and post-menopausal women receiving TAM for treatment of early-stage breast cancer or prevention who were enrolled in a randomized, placebo-controlled trial of diindolylmethane. Eligibility for this analysis included participants with FWD-MRI scans at baseline, 6 and 12 months. Median time on TAM at baseline was 13 months (IQR, 5–26 months). All MRI images were acquired on a 1.5T GE Signa NV-CV/i scanner. Automated breast segmentation was performed using MATLAB software and validated against manual ROI drawings. MRI-based BD was calculated as the ratio of breast voxels with &lt;80% apparent fat fraction (Fra80) over the entire breast, a measure previously shown by our group to be highly correlated with mammography-derived BD. For 40 participants, the unaffected, contralateral breast was analyzed. For 4 patients with two unaffected breasts, BD data from the left breast were analyzed. Change in BD was conservatively defined as &gt; 2 times the test-retest variability of Fra80 (0.032). McNemar's test was used to test the association between change from baseline to 6 months and change from baseline to 12 months.

Results and Discussion: At 12 months, 15 (34%) participants had a decrease in BD, whereas 29 (66%) remained unchanged or increased. Of these 29, 28 also had no decrease at 6 months (specificity = 97%), and 9 of the 15 women who showed a decrease at 12 months had a decrease at 6 months (sensitivity = 60%; McNemar's test, P = 0.06). Conversely, for those women with a measured decrease in BD from baseline to 6 months, 9 of 10 had a measured decrease at 12 months. A study limitation is inclusion of participants on TAM for varying duration as the greatest change in BD likely would have occurred earlier. Ongoing efforts will focus on FWD-MRI for measures of change in BD in patients initiating TAM.

Conclusion: Use of the specified cut point would fail to detect a decrease in BD at 12 months in 40% of women. However, a decrease in BD from baseline to 6 months was highly associated with decrease from baseline to 12 months and in some women may be useful as an early biomarker of effect. Ongoing effort is needed to determine the impact of factors such as baseline BD, menopausal status, and time on TAM in misclassification of BD change using the 6-month measure.

Acknowledgement: NIH grants CA149417, CA161534.

Citation Format: Ding J, Thompson PA, Wertheim BC, Roe DJ, Marron MT, Altbach MI, Galons J-P, Wang F, Thomson CA, Huang C, Stopeck A. Breast density change at 6 months is associated with change at 12 months as measured by fat-water decomposition MRI in women on tamoxifen [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 P6-09-19.

Abstract P3-02-03: Accurate and reliable automated breast density measurements with no ionizing radiation using fat-water decomposition MRI

Objective Breast density(BD) is a measure of the distribution of variable tissue types within the breast and higher BD has been shown to positively correlate with breast cancer risk. As such, the accurate measurement of BD has become a priority for risk assessment and for evaluating the effects of prevention strategies aimed at reducing BD. Mammography(MG) is the most common method of BD determination but is limited by the exposure to ionizing radiation, particularly for studies requiring repeated measures. BD derived from fat-water decomposition magnetic resonance imaging(FWMRI-BD) has been proposed as an alternative, safe, and quantitative method for BD. To optimize its use, we developed a new FWMRI-BD that is automated, more accurate and reliable. In this study, we compare our automated method to digital MG and a previous reported algorithm for MRI derived BD.

Methods From a completed prevention trial, 42 pre- and post-menopausal patients receiving tamoxifen therapy for early stage breast cancer or as primary chemoprevention were identified. Patients had undergone prior digital MG within 6 months from the date of MRI scan and MG-BD was calculated using a well-established method(Cumulus). MRI scans were performed on a 1.5T GE Signa NV-CV/i scanner using an axial radial IDEAL-GRASE sequence to generate quantitative fat fraction maps of the entire breast. Total acquisition time was &lt; 5 min and automated breast segmentation was applied to all scans. Only the contralateral, unaffected breast was analyzed. Pearson correlation analysis compared BD as measured by MG(range 0-100%) and FWMRI based methods. BD by FWMRI was initially calculated as the ratio of breast voxels with&lt;80% apparent fat fraction(Fra80). Fra80 had been previously shown by our group to correlate with MG-BD(Spearman ρ=0.86, p&lt;0.001). Here, BD was calculated using a new algorithm(FraG+W) that accounts for the total amount of fibroglandular tissue and water content in the breast after correction for fat-water signal intensity bias and fat-water signal shine-through. Reliability of FWMRI measurements was tested in 24 repeated scans from 9 patients and evaluated using intra-class correlation(ICC) analysis.

Results Table 1 shows the correlation and reliability analysis results between MG-BD and FWMRI-BD. Both FWMRI-BD measures(Fra80 and FraG+W) were strongly correlated with MG-BD. More importantly, they exhibit superior test-retest reliability(ICC&gt;0.98) compared to MG-BD values from the literature(reported ICC range 0.91-0.95). FraG+W showed improvement over Fra80 in all measures tested including correlation to MG-BD, dynamic range, standard errors and ICC.

Table 1. Accuracy and Reliability of the FWMRI-BD measuresFWMRI-BDFra80FraG+WPearson correlation coefficient* with MG-BDR=0.86R=0.94Test-retest reliabilitystandard error0.02300.0134dynamic range0.0902 – 0.65370.0736 – 0.6588standard error/ dynamic range4.1%2.3%ICC [95% confidence interval]0.985 [0.966,0.993]0.990 [0.976,0.995]* All P-values &lt; 1e-10

Conclusion The refined and automated FWMRI-BD that quantifies the entire fibroglandular and water content of the breast(FraG+W) strongly correlates with MG-BD and is more accurate and reliable than previous FWMRI-BD method.

Acknowledgement NIH grants CA149417, CA161534.

Citation Format: Ding J, Thompson PA, Gao Y, Marron MT, Wertheim BC, Altbach MI, Galons J-P, Roe DJ, Wang F, Maskarinec G, Thomson CA, Stopeck A, Huang C. Accurate and reliable automated breast density measurements with no ionizing radiation using fat-water decomposition MRI [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 P3-02-03.

Image-guided stereotactic radiosurgery for treatment of spinal hemangioblastoma

OBJECTIVE

Stereotactic radiosurgery (SRS) has been an attractive treatment option for hemangioblastomas, especially for lesions that are surgically inaccessible and in patients with von Hippel-Lindau (VHL) disease and multiple lesions. Although there has been a multitude of studies examining the utility of SRS in intracranial hemangioblastomas, SRS has only recently been used for spinal hemangioblastomas due to technical limitations. The purpose of this study is to provide a long-term evaluation of the effectiveness of image-guided radiosurgery in halting tumor progression and providing symptomatic relief for spinal hemangioblastomas.

METHODS

Between 2001 and 2011, 46 spinal hemangioblastomas in 28 patients were treated using the CyberKnife image-guided radiosurgery system at the authors' institution. Fourteen of these patients also had VHL disease. The median age at treatment was 43.5 years (range 19–85 years). The mean prescription radiation dose to the tumor periphery was 21.6 Gy (range 15–35 Gy). The median tumor volume was 0.264 cm3 (range 0.025–70.9 cm3). Tumor response was evaluated on serial, contrast-enhanced CT and MR images. Clinical response was evaluated by clinical and imaging evaluation.

RESULTS

The mean follow-up for the cohort was 54.3 months. Radiographic follow-up was available for 19 patients with 34 tumors; 32 (94.1%) tumors were radiographically stable or displayed signs of regression. Actuarial control rates at 1, 3, and 5 years were 96.1%, 92.3%, and 92.3%, respectively. Clinical evaluation on follow-up was available for 13 patients with 16 tumors; 13 (81.2%) tumors in 10 patients had symptomatic improvement. No patient developed any complications related to radiosurgery.

CONCLUSIONS

Image-guided SRS is safe and effective for the primary treatment of spinal hemangioblastomas and is an attractive alternative to resection, especially for those with VHL disease.

Physical Activity Modifies the Association between Dietary Protein and Lean Mass of Postmenopausal Women

BACKGROUND

Maintenance of lean muscle mass and related strength is associated with lower risk for numerous chronic diseases of aging in women.

OBJECTIVE

Our aim was to evaluate whether the association between dietary protein and lean mass differs by physical activity level, amino acid composition, and body mass index categories.

DESIGN

We performed a cross-sectional analysis of a prospective cohort.

PARTICIPANTS/SETTING

Participants were postmenopausal women from the Women's Health Initiative with body composition measurements by dual-energy x-ray absorptiometry (n=8,298).

MAIN OUTCOME MEASURES

Our study measured percent lean mass, percent fat mass, and lean body mass index.

STATISTICAL ANALYSES PERFORMED

Linear regression models adjusted for scanner serial number, age, calibrated energy intake, race/ethnicity, neighborhood socioeconomic status, and recreational physical activity were used to determine the relationship between protein intake and body composition measures. Likelihood ratio tests and stratified analysis were used to investigate physical activity and body mass index as potential effect modifiers.

RESULTS

Biomarker-calibrated protein intake was positively associated with percent lean mass; women in the highest protein quintile had 6.3 percentage points higher lean mass than the lowest quintile (P<0.001). This difference rose to 8.5 percentage points for physically active women in the highest protein quintile (P_interaction=0.023). Percent fat mass and lean body mass index were both inversely related to protein intake (both P<0.001). Physical activity further reduced percent fat mass (P_interaction=0.022) and lean body mass index (P_interaction=0.011). Leucine intake was associated with lean mass, as were branched chain amino acids combined (both P<0.001), but not independent of total protein. All associations were observed for normal-weight, overweight, and obese women.

CONCLUSIONS

Protein consumption up to 2.02 g/kg body weight daily is positively associated with lean mass in postmenopausal women. Importantly, those that also engage in physical activity have the highest lean mass across body mass index categories.

Colorectal Adenomas in Participants of the SELECT Randomized Trial of Selenium and Vitamin E for Prostate Cancer Prevention

Selenium and vitamin E micronutrients have been advocated for the prevention of colorectal cancer. Colorectal adenoma occurrence was used as a surrogate for colorectal cancer in an ancillary study to the Selenium and Vitamin E Cancer Prevention Trial (SELECT) for prostate cancer prevention. The primary objective was to measure the effect of selenium (as selenomethionine) on colorectal adenomas occurrence, with the effect of vitamin E (as α-tocopherol) supplementation on colorectal adenoma occurrence considered as a secondary objective. Participants who underwent lower endoscopy while in SELECT were identified from a subgroup of the 35,533 men randomized in the trial. Adenoma occurrence was ascertained from the endoscopy and pathology reports for these procedures. Relative Risk (RR) estimates and 95% confidence intervals (CI) of adenoma occurrence were generated comparing those randomized to selenium versus placebo and to vitamin E versus placebo based on the full factorial design. Evaluable endoscopy information was obtained for 6,546 participants, of whom 2,286 had 1+ adenomas. Apart from 21 flexible sigmoidoscopies, all the procedures yielding adenomas were colonoscopies. Adenomas occurred in 34.2% and 35.7%, respectively, of participants whose intervention included or did not include selenium. Compared with placebo, the RR for adenoma occurrence in participants randomized to selenium was 0.96 (95% CI, 0.90-1.02; P = 0.194). Vitamin E did not affect adenoma occurrence compared with placebo (RR = 1.03; 95% CI, 0.96-1.10; P = 0.38). Neither selenium nor vitamin E supplementation can be recommended for colorectal adenoma prevention. Cancer Prev Res; 10(1); 45-54. ©2016 AACR.

Stereotactic radiosurgery for non-vestibular cranial nerve schwanommas

Non-vestibular cranial nerve schwannomas (NVCNS) are rare lesions, representing <10 % of cranial nerve schwannomas. The optimal treatment for NVCNS is often derived from vestibular schwannomas experience. Surgical resection has been referred to as the first line treatment for those benign tumors, but significant complication rates are reported. Stereotactic radiosurgery (SRS) has arisen as a mainstay of treatment for many benign tumors, including schwanommas. We retrospectively reviewed the outcomes of NVCNS treated by SRS to characterize tumor control, symptom relief, toxicity, and the role of hypo-fractionation of SRS dose. Eighty-eight (88) patients, with ninety-five (95) NVCNS were treated with either single or multi-session SRS from 2001 to 2014. Local control was achieved in 94 % of patients treated (median follow-up of 33 months, range 1-155). Complications were seen in 7.4 % of cases treated with SRS. At 1-year, 57 % of patients had improvement or resolution of their symptoms, while 35 % were stable and 8 % had worsening or increased symptoms. While 42 % received only one session, results on local control were similar for one or multiple sessions (p = 0.424). SRS for NVCNS is a treatment modality that provides excellent local control with minimal complication risk compared to traditional neurosurgical techniques. Tumor control obtained with a multi-session treatment was not significantly different from single session treatment. Safety profile was also comparable for uni or multi-session treatments. We concluded that, as seen in VS treated with CK SRS, radiosurgery treatment can be safely delivered in cases of NVCNS.

MicroRNA Signatures of Colonic Polyps on Screening and Histology

Colorectal cancer and adenoma adjacent to cancer exhibit distinct microRNA (miRNA) alterations in an apparent mucosa-to-adenocarcinoma sequence. The pattern of microRNAs in screen-detected polyps in relation to histologic features and cancer risk has not been investigated. miRNA expression analysis was performed on normal mucosa (NM), hyperplastic polyps (HP), tubular adenomas (TA), tubulovillous adenomas or high-grade dysplasia (TVHG), and serrated polyps [sessile serrated adenoma/polyps (SSA/P) and traditional serrated adenomas (TSA)] in biopsy specimens from 109 patients undergoing screening/surveillance colonoscopy. Generalized linear models were used to identify differentially expressed miRNAs by histologic type and logistic regression to identify miRNA predictors of histopathology. False discovery rate (FDR) was used to control for multiple comparisons. We identified 99 miRNAs differing in at least one of five histopathologic groups (FDR ≤0.05). In a comparison of HPNM versus TVHG, the top most upregulated and downregulated miRNAs in HPNM included miR-145, -143, -107, -194, and -26a (upregulated), and miR-663, -1268, -320b, -1275, and -320b (downregulated; FDR P < 0.05). miR-145 and -619 showed high accuracy to discriminate low- from high-risk polyps without serrated histology (TVHG vs. HPNM + TA; CI, 95.6%), whereas miR-124, -143, and -30a showed high accuracy of separating high-risk polyps (TVHG + TSA) from low-risk polyps (HPNM + TA + SSA/P; CI, 96.0%). For TSAs, miR-125b and -199a were uniquely downregulated relative to HPNMs, and miR-335, -222, and -214 discriminated between non-serrated and serrated histology. Our data support the presence of colorectal cancer-associated miRNA alterations in screen-detected adenomas that may be useful for risk stratification for surveillance interval planning. Cancer Prev Res; 9(12); 942-9. ©2016 AACR.

The DNA Damage Transducer RNF8 Facilitates Cancer Chemoresistance and Progression through Twist Activation

Twist has been shown to cause treatment failure, cancer progression, and cancer-related death. However, strategies that directly target Twist are not yet conceivable. Here we reveal that K63-linked ubiquitination is a crucial regulatory mechanism for Twist activation. Through an E3 ligase screen and biochemical studies, we unexpectedly identified that RNF8 functions as a direct Twist activator by triggering K63-linked ubiquitination of Twist. RNF8-promoted Twist ubiquitination is required for Twist localization to the nucleus for subsequent EMT and CSC functions, thereby conferring chemoresistance. Our histological analyses showed that RNF8 expression is upregulated and correlated with disease progression, EMT features, and poor patient survival in breast cancer. Moreover, RNF8 regulates cancer cell migration and invasion and cancer metastasis, recapitulating the effect of Twist. Together, our findings reveal a previously unrecognized tumor-promoting function of RNF8 and provide evidence that targeting RNF8 is an appealing strategy to tackle tumor aggressiveness and treatment resistance.

Plasma constituents regulate LPS binding to, and release from, the monocyte cell surface

Innate immunity to Gram-negative bacteria involves regulated mechanisms that allow sensitive but limited responses to LPS. Two important pathways that lead to host cell activation and LPS deactivation involve: (i) LPS interactions with CD14 and Toll-like receptor 4 on cells (activation); and (ii) LPS sequestration by plasma lipoproteins (deactivation). Whereas these pathways were previously thought to be independent and essentially irreversible, we found that they are connected by a third pathway: (iii) the movement of LPS from host cells to plasma lipoproteins. Our data show that, in the presence of human plasma, LPS binds transiently to monocyte surfaces and then moves from the cell surface to plasma lipoproteins. Soluble CD14 enhances LPS release from cells in the presence of lipoproteins, whereas LPS binding protein and phospholipid transfer protein do not. The transfer of cell-bound LPS to lipoproteins is accompanied by reduced cell responses to the LPS, suggesting that the movement of LPS from leukocytes into lipoproteins may attenuate host responses to LPS in vivo. Preliminary data suggest that changes that occur in the plasma after trauma or during sepsis decrease LPS binding to leukocytes while greatly increasing the rate of LPS release from cells.

ATM function and its relationship with ATM gene mutations in chronic lymphocytic leukemia with the recurrent deletion (11q22.3-23.2)

Approximately 10–20% of chronic lymphocytic leukemia (CLL) patients exhibit del(11q22–23) before treatment, this cohort increases to over 40% upon progression following chemoimmunotherapy. The coding sequence of the DNA damage response gene, ataxia-telangiectasia-mutated (ATM), is contained in this deletion. The residual ATM allele is frequently mutated, suggesting a relationship between gene function and clinical response. To investigate this possibility, we sought to develop and validate an assay for the function of ATM protein in these patients. SMC1 (structural maintenance of chromosomes 1) and KAP1 (KRAB-associated protein 1) were found to be unique substrates of ATM kinase by immunoblot detection following ionizing radiation. Using a pool of eight fluorescence in situ hybridization-negative CLL samples as a standard, the phosphorylation of SMC1 and KAP1 from 46 del (11q22–23) samples was analyzed using normal mixture model-based clustering. This identified 13 samples (28%) that were deficient in ATM function. Targeted sequencing of the ATM gene of these samples, with reference to genomic DNA, revealed 12 somatic mutations and 15 germline mutations in these samples. No strong correlation was observed between ATM mutation and function. Therefore, mutation status may not be taken as an indicator of ATM function. Rather, a direct assay of the kinase activity should be used in the development of therapies.

Modulatory effects of sCD14 and LBP on LPS-host cell interactions

LPS binding protein (LBP) and CD14 play key roles in promoting innate immunity to Gram-negative bacteria by transferring LPS to the signaling receptor complex, MD-2/Toll-like receptor 4 (TLR4). LBP and soluble CD14 (sCD14) can also inhibit responses to LPS by mechanisms that depend on their concentration and environment; during acute inflammation and infection, their concentrations increase in plasma and extravascular fluids. Whereas low concentrations of LBP enhance responses to LPS, high LBP concentrations can inhibit LPS bioactivity in vitro and in vivo. sCD14 also inhibits cell responses by diverting LPS from membrane-bound CD14 (mCD14) and by promoting LPS efflux from cell-surface mCD14 and transferring it to plasma lipoproteins. In vivo studies support the hypothesis that sCD14 has systemic anti-inflammatory effects, whereas in the tissues it may have pro-inflammatory effects that increase resistance to bacteria. Likewise, LBP increases resistance to Gram-negative bacteria by rapidly triggering pro-inflammatory responses to LPS. Thus, the dual stimulatory and inhibitory mechanisms of sCD14 and LBP may benefit the infected host by promoting inflammation in local sites, where it is needed, while at the same time preventing potentially detrimental systemic responses to LPS.

Celecoxib for the Prevention of Colorectal Adenomas: Results of a Suspended Randomized Controlled Trial

BACKGROUND

Cyclooxygenase (COX)-2 inhibitors such as celecoxib were designed to preserve anti-inflammatory activity without inhibiting COX-1. Downregulation of COX-2 inhibits colorectal carcinogenesis.

METHODS

The Selenium and Celecoxib Trial was a randomized, placebo-controlled trial of once-daily selenium 200 µg and celecoxib 400 mg, alone or together, for colorectal adenoma prevention. Men and women between age 40 and 80 years were eligible following colonoscopic removal of adenomas. The primary outcome was development of new adenomas. Celecoxib was suspended early because of cardiovascular toxicity in other trials. Accrual to selenium or placebo continued. Before suspension, 824 participants were randomly assigned to celecoxib or placebo, of whom 712 (86.4%) were available for analysis. All statistical tests were two-sided.

RESULTS

In the placebo and celecoxib arms of 356 participants each, adenoma detection was 47.5% and 49.7% (relative risk [RR] = 1.04, 95% confidence interval [CI] = 0.90 to 1.21, P = .58), respectively, after median periods of 13.6 and 14.2 months on intervention. Among participants colonoscoped within 12 months of discontinuing intervention (n = 244), overall adenoma recurrence (RR = 0.69, 95% CI = 0.48 to 0.98, P = .04) and recurrence with advanced adenomas (RR = 0.23, 95% CI = 0.07 to 0.80, P = .02) were reduced with celecoxib. Reduction of adenoma recurrence was greatest in participants with previous advanced adenomas. Celecoxib increased risk of hypertension in participants with pre-existing cardiovascular risk factors compared with placebo (hazard ratio = 2.19, 95% CI = 1.07 to 4.50, P = .03).

CONCLUSIONS

Limited-duration celecoxib prevents adenoma recurrence in patients with prior high-risk adenomas, in whom strategies to minimize cardiovascular toxicity might be feasible.

Selenium Supplementation for Prevention of Colorectal Adenomas and Risk of Associated Type 2 Diabetes

BACKGROUND

Selenium supplementation may help to prevent colorectal cancer; as precursors of colorectal cancer, colorectal adenomas are a surrogate for colorectal cancer. Selenium supplementation may increase risk of type 2 diabetes (T2D).

METHODS

The Selenium and Celecoxib (Sel/Cel) Trial was a randomized, placebo controlled trial of selenium 200 µg daily as selenized yeast and celecoxib 400 mg once daily, alone or together, for colorectal adenoma prevention. Men and women between age 40 and 80 years were eligible following colonoscopic removal of colorectal adenomas. The primary outcome was adenoma development. Celecoxib was suspended because of cardiovascular toxicity in other trials, but accrual continued to selenium and placebo. A total of 1621 participants were randomly assigned to selenium or placebo, of whom 1374 (84.8%) were available for analysis. All statistical tests were two-sided.

RESULTS

In the respective placebo and selenium arms of 689 and 685 participants, adenoma detection after medians of 33.6 (range = 0.0-85.1 months) and 33.0 months (range = 0.0-82.6 months) were 42.8% and 44.1% (relative risk [RR] = 1.03, 95% confidence interval [CI] = 0.91 to 1.16, P = .68). In participants with baseline advanced adenomas, adenoma recurrence was reduced by 18% with selenium (RR = 0.82, 95% CI = 0.71 to 0.96, P = .01). In participants receiving selenium, the hazard ratio for new-onset T2D was 1.25 (95% CI = 0.74 to 2.11, P = .41), with a statistically significantly increased risk of selenium-associated T2D among older participants (RR = 2.21; 95% CI = 1.04 to 4.67, P = .03).

CONCLUSIONS

Overall, selenium did not prevent colorectal adenomas and showed only modest benefit in patients with baseline advanced adenomas. With limited benefit and similar increases in T2D to other trials, selenium is not recommended for preventing colorectal adenomas in selenium-replete individuals.

Phase II study of metformin for reduction of obesity-associated breast cancer risk: a randomized controlled trial protocol

Background

Two-thirds of U.S. adult women are overweight or obese. High body mass index (BMI) and adult weight gain are risk factors for a number of chronic diseases, including postmenopausal breast cancer. The higher postmenopausal breast cancer risk in women with elevated BMI is likely to be attributable to related metabolic disturbances including altered circulating sex steroid hormones and adipokines, elevated pro-inflammatory cytokines, and insulin resistance. Metformin is a widely used antidiabetic drug that has demonstrated favorable effects on metabolic disturbances and as such may lead to lower breast cancer risk in obese women. Further, the anti-proliferative effects of metformin suggest it may decrease breast density, an accepted biomarker of breast cancer risk.

Methods/design

This is a Phase II randomized, double-blind, placebo-controlled trial of metformin in overweight/obese premenopausal women who have elements of metabolic syndrome. Eligible participants will be randomized to receive metformin 850 mg BID (n = 75) or placebo (n = 75) for 12 months. The primary endpoint is change in breast density, based on magnetic resonance imaging (MRI) acquired fat-water features. Secondary outcomes include changes in serum insulin levels, serum insulin-like growth factor (IGF)-1 to insulin-like growth factor binding protein (IGFBP)-3 ratio, serum IGF-2 levels, serum testosterone levels, serum leptin to adiponectin ratio, body weight, and waist circumference. Exploratory outcomes include changes in metabolomic profiles in plasma and nipple aspirate fluid. Changes in tissue architecture as well as cellular and molecular targets in breast tissue collected in a subgroup of participants will also be explored.

Discussion

The study will evaluate whether metformin can result in favorable changes in breast density, select proteins and hormones, products of body metabolism, and body weight and composition. The study should help determine the potential breast cancer preventive activity of metformin in a growing population at risk for multiple diseases.

Trial registration

ClinicalTrials.gov Identifier: NCT02028221. Registered on January 2, 2014. Grant #: 1R01CA172444-01A1 awarded on Sept 11, 2013.

Decadal-Scale Forecasting of Climate Drivers for Marine Applications

Climate influences marine ecosystems on a range of time scales, from weather-scale (days) through to climate-scale (hundreds of years). Understanding of interannual to decadal climate variability and impacts on marine industries has received less attention. Predictability up to 10 years ahead may come from large-scale climate modes in the ocean that can persist over these time scales. In Australia the key drivers of climate variability affecting the marine environment are the Southern Annular Mode, the Indian Ocean Dipole, the El Niño/Southern Oscillation, and the Interdecadal Pacific Oscillation, each has phases that are associated with different ocean circulation patterns and regional environmental variables. The roles of these drivers are illustrated with three case studies of extreme events-a marine heatwave in Western Australia, a coral bleaching of the Great Barrier Reef, and flooding in Queensland. Statistical and dynamical approaches are described to generate forecasts of climate drivers that can subsequently be translated to useful information for marine end users making decisions at these time scales. Considerable investment is still needed to support decadal forecasting including improvement of ocean-atmosphere models, enhancement of observing systems on all scales to support initiation of forecasting models, collection of important biological data, and integration of forecasts into decision support tools. Collaboration between forecast developers and marine resource sectors-fisheries, aquaculture, tourism, biodiversity management, infrastructure-is needed to support forecast-based tactical and strategic decisions that reduce environmental risk over annual to decadal time scales.

Body shape, adiposity index, and mortality in postmenopausal women: Findings from the Women's Health Initiative

OBJECTIVE

Studies evaluating the relationship between body mass index (BMI) and mortality demonstrate a U-shaped association. To expand, this study evaluated the relationship between adiposity indices, a body shape index (ABSI) and body adiposity index (BAI), and mortality in 77,505 postmenopausal women.

METHODS

A prospective cohort analysis was conducted in the Women's Health Initiative to ascertain the independent relationships between adiposity indices and mortality in order to inform on the clinical usefulness of alternate measures of mortality risk. ABSI (waist circumference (cm)/[BMI(2/3) × height (cm)(1/2) ]), BAI (hip circumference (cm)/[height (m)(1.5) ] - 18), weight, BMI, and waist circumference (WC) were evaluated in relation to mortality risk using adjusted Cox proportional hazards regression models.

RESULTS

ABSI showed a linear association with mortality (HR, 1.37; 95% CI, 1.28-1.47 for quintile 5 vs. 1) while BMI and BAI had U-shaped relationships with HR of 1.30; 95% CI, 1.20-1.40 for obesity II/III BMI and 1.06, 95% CI, 0.99-1.13 for BAI. Higher WC (HR, 1.21; 95% CI, 1.13-1.29 for quintile 5 vs. 1) showed relationships similar to BMI.

CONCLUSIONS

ABSI appears to be a clinically useful measure for estimating mortality risk, perhaps more so than BAI and BMI in postmenopausal women.

EFFECT OF SELENIUM SUPPLEMENTATION ON PROTEOMIC SERUM BIOMARKERS IN ELDERLY MEN

OBJECTIVES

To determine the effect of selenium supplementation on the human proteomic profile.

DESIGN

Serum samples were collected in this pilot study from a randomized placebo controlled Phase 2 clinical trial (Watchful Waiting (WW)).

SETTING

Subjects were followed every three months for up to five years at the University of Arizona Prostate Cancer Prevention Program.

PARTICIPANTS

One hundred and forty men (age < 85 years) had biopsy-proven prostate cancer, a Gleason sum score less than eight, no metastatic cancer, and no prior treatment for prostate cancer.

INTERVENTION

As part of the WW trial, men were randomized to placebo, selenium 200 μg/day or selenium 800 μg/day. For the purpose of the current study, 40 subjects enrolled in the WW study (20 from the placebo group and 20 from Se 800 μg/day group) were selected.

MEASUREMENTS

Baseline serum samples were collected at each follow-up visit and stored at -80 degrees Celsius. A multiplexed proteomic panel investigated changes in 120 proteins markers simultaneously.

RESULTS

Thirteen proteins (Apolipoprotein J, IL-10, IL-1 alpha, MMP-3, IL-12p70, IL-2 receptor alpha, cathepsin B, eotaxin, EGFR, FGF-basic, myeloperoxidase, RANTES, TGF-beta) were determined to be either statistically (p-value < 0.05) or marginally significantly (0.05 < p-value <0.1) changed in the selenium supplemented group as compared to placebo.

CONCLUSION

Although independent validation of these results is needed, this study is the first of its kind to utilize high throughput fluorescence based protein multiplex panel in analyzing changes in the proteomic profile due to selenium supplementation. Results from this study provide insight into the ability of selenium to modulate numerous protein markers and thus impact various biological processes in humans.

Umbilical cord blood graft engineering: challenges and opportunities

We are entering a very exciting era in umbilical cord blood transplantation (UCBT), where many of the associated formidable challenges may become treatable by ex vivo graft manipulation and/or adoptive immunotherapy utilizing specific cellular products. We envisage the use of double UCBT rather than single UCBT for most patients; this allows for greater ability to treat larger patients as well as to manipulate the graft. Ex vivo expansion and/or fucosylation of one cord will achieve more rapid engraftment, minimize the period of neutropenia and also give certainty that the other cord will provide long-term engraftment/immune reconstitution. The non-expanded (and future dominant) cord could be chosen for characteristics such as better HLA matching to minimize GvHD, or larger cell counts to enable part of the unit to be utilized for the development of specific cellular therapies such as the production of virus-specific T-cells or chimeric-antigen receptor T-cells which are reviewed in this study.

Inactivation of Adenomatous Polyposis Coli Reduces Bile Acid/Farnesoid X Receptor Expression through Fxr gene CpG Methylation in Mouse Colon Tumors and Human Colon Cancer Cells

BACKGROUND

The farnesoid X receptor (FXR) regulates bile acid (BA) metabolism and possesses tumor suppressor functions. FXR expression is reduced in colorectal tumors of subjects carrying inactivated adenomatous polyposis coli (APC). Identifying the mechanisms responsible for this reduction may offer new molecular targets for colon cancer prevention.

OBJECTIVE

We investigated how APC inactivation influences the regulation of FXR expression in colonic mucosal cells. We hypothesized that APC inactivation would epigenetically repress nuclear receptor subfamily 1, group H, member 4 (FXR gene name) expression through increased CpG methylation.

METHODS

Normal proximal colonic mucosa and normal-appearing adjacent colonic mucosa and colon tumors were collected from wild-type C57BL/6J and Apc-deficient (Apc(Min) (/+)) male mice, respectively. The expression of Fxr, ileal bile acid-binding protein (Ibabp), small heterodimer partner (Shp), and cyclooxygenase-2 (Cox-2) were determined by real-time polymerase chain reaction. In both normal and adjacent colonic mucosa and colon tumors, we measured CpG methylation of Fxr in bisulfonated genomic DNA. In vitro, we measured the impact of APC inactivation and deoxycholic acid (DCA) treatment on FXR expression in human colon cancer HCT-116 cells transfected with silencing RNA for APC and HT-29 cells carrying inactivated APC.

RESULTS

In Apc(Min) (/+) mice, constitutive CpG methylation of the Fxrα3/4 promoter was linked to reduced (60-90%) baseline Fxr, Ibabp, and Shp and increased Cox-2 expression in apparently normal adjacent mucosa and colon tumors. Apc knockdown in HCT-116 cells increased cellular myelocytomatosis (c-MYC) and lowered (∼50%) FXR expression, which was further reduced (∼80%) by DCA. In human HCT-116 but not HT-29 colon cancer cells, DCA induced FXR expression and lowered CpG methylation of FXR.

CONCLUSIONS

We conclude that the loss of APC function favors the silencing of FXR expression through CpG hypermethylation in mouse colonic mucosa and human colon cells, leading to reduced expression of downstream targets (SHP, IBABP) involved in BA homeostasis while increasing the expression of factors (COX-2, c-MYC) that contribute to inflammation and colon cancer.

National trends in inpatient admissions following stereotactic radiosurgery and the in-hospital patient outcomes in the United States from 1998 to 2011

PURPOSE

This study sought to examine trends in stereotactic radiosurgery (SRS) and in-hospital patient outcomes on a national level by utilizing national administrative data from the Nationwide Inpatient Sample (NIS) database.

METHODS AND MATERIALS

Using the NIS database, all discharges where patients underwent inpatient SRS were included in our study from 1998 - 2011 as designated by the ICD9-CM procedural codes. Trends in the utilization of primary and adjuvant SRS, in-hospital complications and mortality, and resource utilization were identified and analyzed.

RESULTS

Our study included over 11,000 hospital discharges following admission for primary SRS or for adjuvant SRS following admission for surgery or other indication. The most popular indication for SRS continues to be treatment of intracranial metastatic disease (36.7%), but expansion to primary CNS lesions and other non-malignant pathology beyond trigeminal neuralgia has occurred over the past decade. Second, inpatient admissions for primary SRS have declined by 65.9% over this same period of time. Finally, as inpatient admissions for SRS become less frequent, the complexity and severity of illness seen in admitted patients has increased over time with an increase in the average comorbidity score from 1.25 in the year 2002 to 2.29 in 2011, and an increase in over-all in-hospital complication rate of 2.8 times over the entire study period.

CONCLUSIONS

As the practice of SRS continues to evolve, we have seen several trends in associated hospital admissions. Overall, the number of inpatient admissions for primary SRS has declined while adjuvant applications have remained stable. Over the same period, there has been associated increase in complication rate, length of stay, and mortality in inpatients. These associations may be explained by an increase in the comorbidity-load of admitted patients as more high-risk patients are selected for admission at inpatient centers while more stable patients are increasingly being referred to outpatient centers.

Abstract A82: Identifying differentially expressed microRNAs as investigational tools in postpartum breast cancer in Hispanic women

The risk of breast cancer transiently increases immediately following pregnancy; peaking between 3-7 years. The biology that underlies this risk window and the effect on the natural history of the disease is unknown. MicroRNAs (miRNAs) are small, non-coding RNAs that have been shown to be dysregulated in breast cancer. Utilizing a quantitative RT-PCR approach, we profiled the expression pattern of 355 miRNAs across 56 formalin-fixed, paraffin embedded breast tumor tissue samples from multiparous Hispanic women. Based on a data-driven splitting of the expression pattern of the 355 miRNAs, the case series was separated into two groups based on time since last full-term pregnancy (TSLFTP): a) an early group representing women diagnosed with breast cancer ≤ 5.2 years postpartum (n=12); and b) a late group representing women diagnosed with breast cancer ≥ 5.3 years postpartum (n=44). We identified 15 miRNAs with significant differential expression between the early and late postpartum groups. Ten miRNAs had a two-fold or higher difference in expression, with miR-138, miR-660, miR-31, miR-135b, miR-17, miR-454, and miR-934 overexpressed in the early versus the late group; while miR-892a, miR-199a-5p, and miR-542-5p were overexpressed in the late versus the early postpartum group. Further analysis of the miRNA expression data demonstrated that 60% of the identified differentially expressed miRNAs are encoded on the X chromosome, with several miRNAs found together in miRNA gene clusters. Additionally, DNA methylation, measured using a Sequenom MassARRAY, demonstrated that three out of five tested miRNA genes (mir-31, mir-135b, and mir-138-2) had a lower mean methylation in the early versus late postpartum group, and negatively correlated with miRNA expression. In summary, we have identified miRNAs that are differentially expressed and differentially methylated between tumors of the early versus late postpartum, suggesting that potential differences in epigenetic regulation may exist in the postpartum breast cancers.

Citation Format: José L. Muñoz-Rodríguez, Lukas Vrba, Chengcheng Hu, Patricia A. Thompson, Maria Elena Martinez, Bernard W. Futscher. Identifying differentially expressed microRNAs as investigational tools in postpartum breast cancer in Hispanic women. [abstract]. In: Proceedings of the Seventh AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 9-12, 2014; San Antonio, TX. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2015;24(10 Suppl):Abstract nr A82.

Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: the challenge ahead

Low-dose exposures to common environmental chemicals that are deemed safe individually may be combining to instigate carcinogenesis, thereby contributing to the incidence of cancer. This risk may be overlooked by current regulatory practices and needs to be vigorously investigated.

Lifestyle factors are responsible for a considerable portion of cancer incidence worldwide, but credible estimates from the World Health Organization and the International Agency for Research on Cancer (IARC) suggest that the fraction of cancers attributable to toxic environmental exposures is between 7% and 19%. To explore the hypothesis that low-dose exposures to mixtures of chemicals in the environment may be combining to contribute to environmental carcinogenesis, we reviewed 11 hallmark phenotypes of cancer, multiple priority target sites for disruption in each area and prototypical chemical disruptors for all targets, this included dose-response characterizations, evidence of low-dose effects and cross-hallmark effects for all targets and chemicals. In total, 85 examples of chemicals were reviewed for actions on key pathways/mechanisms related to carcinogenesis. Only 15% (13/85) were found to have evidence of a dose-response threshold, whereas 59% (50/85) exerted low-dose effects. No dose-response information was found for the remaining 26% (22/85). Our analysis suggests that the cumulative effects of individual (non-carcinogenic) chemicals acting on different pathways, and a variety of related systems, organs, tissues and cells could plausibly conspire to produce carcinogenic synergies. Additional basic research on carcinogenesis and research focused on low-dose effects of chemical mixtures needs to be rigorously pursued before the merits of this hypothesis can be further advanced. However, the structure of the World Health Organization International Programme on Chemical Safety ‘Mode of Action’ framework should be revisited as it has inherent weaknesses that are not fully aligned with our current understanding of cancer biology.

Environmental immune disruptors, inflammation and cancer risk

An emerging area in environmental toxicology is the role that chemicals and chemical mixtures have on the cells of the human immune system. This is an important area of research that has been most widely pursued in relation to autoimmune diseases and allergy/asthma as opposed to cancer causation. This is despite the well-recognized role that innate and adaptive immunity play as essential factors in tumorigenesis. Here, we review the role that the innate immune cells of inflammatory responses play in tumorigenesis. Focus is placed on the molecules and pathways that have been mechanistically linked with tumor-associated inflammation. Within the context of chemically induced disturbances in immune function as co-factors in carcinogenesis, the evidence linking environmental toxicant exposures with perturbation in the balance between pro- and anti-inflammatory responses is reviewed. Reported effects of bisphenol A, atrazine, phthalates and other common toxicants on molecular and cellular targets involved in tumor-associated inflammation (e.g. cyclooxygenase/prostaglandin E2, nuclear factor kappa B, nitric oxide synthesis, cytokines and chemokines) are presented as example chemically mediated target molecule perturbations relevant to cancer. Commentary on areas of additional research including the need for innovation and integration of systems biology approaches to the study of environmental exposures and cancer causation are presented.

CYP24A1 and CYP27B1 Polymorphisms, Concentrations of Vitamin D Metabolites, and Odds of Colorectal Adenoma Recurrence

Development of colorectal adenoma and cancer are associated with low circulating 25-hydroxyvitamin D [25(OH)D] levels. However, less is known regarding colorectal neoplasia risk and variation in CYP27B1 or CYP24A1, genes encoding the enzymes responsible for the synthesis and catabolism of 1α,25-hydroxyvitamin D [1,25(OH)2D]. This study examined associations between CYP27B1 and CYP24A1 polymorphisms, circulating 25(OH)D and 1,25(OH)2D concentrations, and colorectal adenoma recurrence in a pooled sample from 2 clinical trials (n = 1,188). Nominal associations were observed between increasing copies of the T allele in CYP24A1 rs927650 and 25(OH)D concentrations (P = 0.02); as well as colorectal adenoma recurrence, with odds ratios (95% confidence intervals) of 1.30 (0.99-1.70) and 1.38 (1.01-1.89) for heterozygotes and minor allele homozygotes, respectively (P = 0.04). In addition, a statistically significant relationship between CYP24A1 rs35051736, a functional polymorphism, and odds for advanced colorectal adenoma recurrence was observed (P < 0.001). Further, nominally statistically significant interactions were observed between rs2296241 and 25(OH)D as well as rs2762939 and 1,25(OH)2D (P(interaction) = 0.10, respectively). Overall, CYP24A1 polymorphisms may influence the development of advanced lesions, and modify the effect of vitamin D metabolites on adenoma recurrence. Further study is necessary to characterize the differences between circulating vitamin D metabolite measurements compared to cellular level activity in relation to cancer risk.

Abstract 1903: Application of lipidomics to a sulindac intervention of aromatase inhibitor-induced pain

(a) Introduction. The regular use of non-steroidal anti-inflammatory drugs (NSAIDs) has been associated with a lower risk for epithelial cancers including breast. NSAIDs block cyclooxygenase (COX)-1 and -2 enzyme metabolism of Ω-6 polyunsaturated fatty acids (PUFA) to prostaglandins (PGs). Additionally, Ω-6 and Ω-3 PUFA are metabolized by lipoxygenases (LOX) and cytochrome P450 (CYP450) enzyme families to produce over 100 metabolites known as ‘oxylipins’. Oxylipins exhibit a wide spectrum of biological activity including mediators of pain and inflammation.

The overarching objective of the work is to determine if sulindac (an NSAID) intervention changes oxylipin profiles in breast cancer patients, and if individual oxylipins are related to pain caused by aromatase inhibitors (AI).

(b) Methods. This work takes place within the context of an R01-funded single arm, open-label clinical trial of sulindac (N = 100). Breast cancer patients that are stable on AIs complete pain and quality of life questionnaires, and provide blood and urine samples after a 4-week NSAID washout, after a 3 month observation period, at baseline and 3, 6 and 12 months on sulindac intervention (150 mg bid). Oxylipins were quantified in blood and urine (n = 10) at the end of washout, baseline, and after 3 months on sulindac using liquid chromatography (LC) mass spectrometry (MS)-based methods.

(c) Results. We quantified 62 total oxylipins in plasma and 87 in urine. Thus far, our analysis has focused on plasma oxylipins. Wilcoxon signed-rank tests were used to compare oxylipin levels at baseline and after 3 months of sulindac. COX metabolites of both Ω-6 and Ω-3 PUFA were non-significantly decreased. In terms of Ω-6 metabolites, 7 LOX products were significantly decreased 11-HETE (P = 0.028), 15-HETE (P = 0.037), 9,12,13-TriHOME (P = 0.017), 9,10,13-TriHOME (P = 0.012), 8-HETE (P = 0.028), 9-HETE (P = 0.028), and 12-HETE (P = 0.047). Significantly decreased Ω-6 CYP450 metabolites were 15(S)-HETrE (P = 0.028), and 5,6-DiHETrE (P = 0.028). The Ω-3 metabolites that significantly decreased were the LOX-derived 5-HEPE (P = 0.022), and 15-HEPE (P = 0.028), and CYP450-derived 5,15-DiHETE (P = 0.047), 5,6-DiHETE (P = 0.009), and 15,16-DiHODE (P = 0.012).

Thus far 53% of participants reported pain other than “every day types of pain” post-washout. The Ω-6 CYP450 metabolite 11(12)-EpETrE was significantly correlated with both “worst pain” (ρ = -0.669; P = 0.034) and severity (ρ = -0.778; P = 0.008). The Ω-6 CYP450 metabolite 20-HETE was significantly correlated with severity (ρ = -0.714; P = 0.047).

(d) Conclusions. Our preliminary data indicate that oxylipin profiles change in response to sulindac and may be related to pain. Success in shifting plasma oxylipin profiles toward an anti-inflammatory/anti-thromobotic/cardioprotective profile would maximize efficacy and to reduce potential toxicities of NSAIDs within the context of for prevention of breast and other cancers.

Citation Format: Jessica Anne Miller, Betsy Werthiem, Jun Yang, Bruce Hammock, Denise Roe, Alison Stopeck, Patricia A. Thompson. Application of lipidomics to a sulindac intervention of aromatase inhibitor-induced pain. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1903. doi:10.1158/1538-7445.AM2015-1903

Dietary polyamine intake and colorectal cancer risk in postmenopausal women

BACKGROUND

Putrescine, spermidine, and spermine (i.e., polyamines) are small cationic amines synthesized by cells or acquired from the diet or gut bacteria. Polyamines are required for both normal and colorectal cancer (CRC) cell growth.

OBJECTIVE

We investigated the association between dietary polyamines and risk of CRC incidence and mortality.

DESIGN

The study was a prospective analysis in 87,602 postmenopausal women in the Women's Health Initiative Observational Study. Multivariate Cox regression was used to calculate HRs and 95% CIs.

RESULTS

Total dietary polyamine intake (mean ± SD: 289.2 ± 127.4 μmol/d) was not positively associated with CRC in fully adjusted models. Instead, intake ≥179.67 μmol/d was associated with reduced risk of CRC [HR (95% CI): 0.82 (0.68, 1.00), 0.81 (0.66, 0.99), 0.91 (0.74, 1.12), and 0.80 (0.62, 1.02) for quintiles 2-5, respectively, compared with quintile 1]. Reduced risk was not significant across all quintiles. Polyamines were not significantly associated with CRC-specific mortality in fully adjusted models. When stratified by risk factors for CRC, only body mass index (BMI) and fiber intake significantly modified the association between polyamine intake and CRC. In women with BMI (in kg/m²) ≤25 or fiber consumption above the median, polyamine intake was associated with significantly lower risk of CRC.

CONCLUSIONS

No positive association between dietary polyamines and CRC or CRC-specific mortality risk in women was observed. Instead, a protective effect of dietary polyamines was suggested in women with some CRC risk-lowering behaviors in particular. These results are consistent with emerging evidence that exogenous polyamines may be beneficial in colon health and warrant additional study.

Differentially expressed microRNAs in postpartum breast cancer in Hispanic women

The risk of breast cancer transiently increases immediately following pregnancy; peaking between 3-7 years. The biology that underlies this risk window and the effect on the natural history of the disease is unknown. MicroRNAs (miRNAs) are small non-coding RNAs that have been shown to be dysregulated in breast cancer. We conducted miRNA profiling of 56 tumors from a case series of multiparous Hispanic women and assessed the pattern of expression by time since last full-term pregnancy. A data-driven splitting analysis on the pattern of 355 miRNAs separated the case series into two groups: a) an early group representing women diagnosed with breast cancer ≤ 5.2 years postpartum (n = 12), and b) a late group representing women diagnosed with breast cancer ≥ 5.3 years postpartum (n = 44). We identified 15 miRNAs with significant differential expression between the early and late postpartum groups; 60% of these miRNAs are encoded on the X chromosome. Ten miRNAs had a two-fold or higher difference in expression with miR-138, miR-660, miR-31, miR-135b, miR-17, miR-454, and miR-934 overexpressed in the early versus the late group; while miR-892a, miR-199a-5p, and miR-542-5p were underexpressed in the early versus the late postpartum group. The DNA methylation of three out of five tested miRNAs (miR-31, miR-135b, and miR-138) was lower in the early versus late postpartum group, and negatively correlated with miRNA expression. Here we show that miRNAs are differentially expressed and differentially methylated between tumors of the early versus late postpartum, suggesting that potential differences in epigenetic dysfunction may be operative in postpartum breast cancers.

Concentrations of the vitamin D metabolite 1,25(OH)2D and odds of metabolic syndrome and its components

AIM

Few epidemiological studies have investigated the association between circulating concentrations of the active vitamin D metabolite 1,25(OH)2D and metabolic syndrome. We sought to determine whether blood levels of 1,25(OH)2D are associated with metabolic syndrome and its individual components, including waist circumference, triglycerides, blood pressure, and glucose, and high-density lipoprotein. We also investigated these associations for the more abundant precursor vitamin D metabolite, 25(OH)D.

METHODS

Participants from two completed clinical trials of colorectal neoplasia with available metabolic syndrome data and blood samples for measurement of 1,25(OH)2D (n=1048) and 25(OH)D (n=2096) were included. Cross-sectional analyses of the association between concentrations of 1,25(OH)2D, 25(OH)D, metabolic syndrome, and its components were conducted.

RESULTS

A statistically significant inverse association was observed for circulating concentrations of 1,25(OH)2D and metabolic syndrome, with adjusted ORs (95% CIs) of 0.73 (0.52-1.04) and 0.52 (0.36-0.75) for the second and third tertiles of 1,25(OH)2D, respectively (p-trend <0.001). Significant inverse relationships were also observed between 1,25(OH)2D and high triglycerides (p-trend <0.001), and low high-density lipoprotein (p-trend <0.001). For 25(OH)D concentrations, significant inverse associations were found for metabolic syndrome (p-trend <0.01), high waist circumference (p-trend <0.04) and triglyceride levels (p-trend <0.01). Participants with 25(OH)D ≥30 ng/ml and in the highest tertile of 1,25(OH)2D demonstrated significantly lower odds of metabolic syndrome, with an OR (95% CI) of 0.38 (0.19-0.75) compared to those in the lowest category for both metabolites.

CONCLUSION

These results provide new evidence that the relatively rarely-studied active hormonal form of vitamin D, 1,25(OH)2D, is associated with metabolic syndrome and its components, and confirm prior findings for 25(OH)D. The finding that 1,25(OH)2D is related to high-density lipoprotein, while 25(OH)D is not, suggests that there may be an independent mechanism of action for 1,25(OH)2D in relation to metabolic dysregulation.

Levels of tritium in soils and vegetation near Canadian nuclear facilities releasing tritium to the atmosphere: implications for environmental models

Concentrations of organically bound tritium (OBT) and tritiated water (HTO) were measured over two growing seasons in vegetation and soil samples obtained in the vicinity of four nuclear facilities and two background locations in Canada. At the background locations, with few exceptions, OBT concentrations were higher than HTO concentrations: OBT/HTO ratios in vegetation varied between 0.3 and 20 and values in soil varied between 2.7 and 15. In the vicinity of the four nuclear facilities OBT/HTO ratios in vegetation and soils deviated from the expected mean value of 0.7, which is used as a default value in environmental transfer models. Ratios of the OBT activity concentration in plants ([OBT]plant) to the OBT activity concentration in soils ([OBT]soil) appear to be a good indicator of the long-term behaviour of tritium in soil and vegetation. In general, OBT activity concentrations in soils were nearly equal to OBT activity concentrations in plants in the vicinity of the two nuclear power plants. [OBT]plant/[OBT]soil ratios considerably below unity observed at one nuclear processing facility represents historically higher levels of tritium in the environment. The results of our study reflect the dynamic nature of HTO retention and OBT formation in vegetation and soil during the growing season. Our data support the mounting evidence suggesting that some parameters used in environmental transfer models approved for regulatory assessments should be revisited to better account for the behavior of HTO and OBT in the environment and to ensure that modelled estimates (e.g., plant OBT) are appropriately conservative.