Design improvement and experimental study on shell and tube condenser for bio-oil recovery from fast pyrolysis of wheat straw biomass

In this study, the design improvement was done in a shell and tube condenser for improved heat transfer and condensation of bio-oil vapour. The developed condenser has split shell and segmental baffles, which divide the shell in various zones and condensate collection points. The fast pyrolysis of wheat straw was done and the bio-oil vapour condensate collected from various outlets located at bottom of condenser shell. From experimental results it was found that production of bio-oil increased from 10.2 to 20.8% with increase in cooling water flow rate from 1000 to 2500 L/h; but, further increasing it beyond 2500 L/h provide marginal effects on production of bio-oil. The production of bio-oil increased from 15.2 to 20.7% as sweep gas flow rate was increased from 20 to 40 L/min at 2500 L/h of cooling water flow rate. But, further increase in sweep gas flow rate beyond 40 L/min resulted in to decrease in production of bio-oil. The novelty of this work is development of improved condenser with segmental baffles, which help in fractional condensation of bio-oil vapour, split shell for cleaning of outer surface of the cooling water tubes and compact design of condenser for optimal condensation of bio-oil.

S-nitrosylated and non-nitrosylated COX2 have differential expression and distinct subcellular localization in normal and breast cancer tissue

Immunohistochemical (IHC) staining in breast cancer shows both gain and loss of COX2 expression with disease risk and progression. We investigated four common COX2 antibody clones and found high specificity for purified human COX2 for three clones; however, recognition of COX2 in cell lysates was clone dependent. Biochemical characterization revealed two distinct forms of COX2, with SP21 recognizing an S-nitrosylated form, and CX229 and CX294 recognizing non-nitrosylated COX2 antigen. We found S-nitrosylated and non-nitrosylated COX2 occupy different subcellular locations in normal and breast cancer tissue, implicating distinct synthetic/trafficking pathways and function. Dual stains of ~2000 breast cancer cases show early-onset breast cancer had increased expression of both forms of COX2 compared to postmenopausal cases. Our results highlight the strengths of using multiple, highly characterized antibody clones for COX2 IHC studies and raise the prospect that S-nitrosylation of COX2 may play a role in breast cancer biology.

Erythrocyte membrane fatty acids and breast cancer risk by tumor tissue expression of immuno-inflammatory markers and fatty acid synthase: a nested case-control study

BACKGROUND

Previous studies of fatty acids and breast cancer risk have shown mixed results, which may be due in part to tumor heterogeneity. Prior research has also illustrated an important role of specific fatty acids in immune regulation, T cell function, and inflammation, indicating that the effects of specific fatty acids on breast cancer risk may vary by tumor expression of immuno-inflammatory markers. We therefore aimed to evaluate the relationships between prediagnostic erythrocyte membrane fatty acids and breast cancer risk by tumor tissue expression of immuno-inflammatory markers (CD4, CD8, CD20, CD163, COX-2) and fatty acid synthase (FAS).

METHODS

We conducted a matched case-control study nested within the Nurses' Health Study II (n = 235 cases and 235 controls). Blood samples were collected from 1996 to 1999. Tumor tissue blocks were collected for cases diagnosed after blood collection and through 2006. Unconditional nominal polytomous logistic regression adjusted for matching factors and potential confounders was used to assess whether associations between fatty acids and breast cancer risk varied by tumor expression subtype, ascertained via immunohistochemistry. Odds ratios (OR) and 95% confidence intervals (CI) were estimated separately by tumor expression subtype using unconditional logistic regression.

RESULTS

Associations between fatty acids and breast cancer risk did not vary substantially by tumor CD4, CD20, CD163, or COX-2. However, n-3 polyunsaturated fatty acids (PUFAs) were inversely associated with CD8^low but not CD8^high cancers (CD8^low OR_{T3 vs T1} = 0.45, 95% CI 0.23-0.87, P_trend = 0.02; CD8^high OR_{T3 vs T1} = 1.19, 95% CI 0.62-2.26, P_trend = 0.62; P_het = 0.04). n-6 PUFAs were suggestively inversely associated with CD8^high but not CD8^low cancers (CD8^high OR_{T3 vs T1} = 0.61, 95% CI 0.32-1.14, P_trend = 0.11; CD8^low OR_{T3 vs T1} = 1.63, 95% CI 0.87-3.04, P_trend = 0.12; P_het = 0.02). Trans fatty acids were positively associated with FAS^high but not FAS^low tumors (FAS^high OR_{T3 vs T1} = 2.94, 95% CI 1.46-5.91, P_trend = 0.002; FAS^low OR_{T3 vs T1} = 0.99, 95% CI 0.52-1.92, P_trend = 0.97; P_het = 0.01).

CONCLUSION

Results indicate that the effects of n-3 PUFAs, n-6 PUFAs, and trans fatty acids on breast cancer risk may vary by tumor tissue expression subtypes. Findings suggest potential immuno-modulatory and FAS-mediated mechanisms.

Loss of myoepithelial calponin-1 characterizes high-risk ductal carcinoma in situ cases, which are further stratified by T cell composition

A hallmark of ductal carcinoma in situ (DCIS) progression is a loss of the surrounding ductal myoepithelium. However, whether compromise in myoepithelial differentiation, rather than overt cellular loss, can be used to predict the risk of DCIS progression is unknown. Here we address this question utilizing pure and mixed DCIS cases (N = 30) as surrogates for DCIS at low and high risk for progression, respectively. We used multiplex immunohistochemical staining to evaluate the relationship between myoepithelial cell differentiation and lymphoid immune cell types associated with poor prognostic DCIS. Our results show that myoepithelial calponin-1 discriminates between pure and mixed DCIS lesions better than histological subtype, presence of necrosis, or nuclear grade. Additionally, focal loss of myoepithelial cells associated with increased PD-1+CD8+ T cells, which suggests a link between the myoepithelium and immune surveillance. To identify associations between calponin-1 expression and immune response, we performed unsupervised hierarchical clustering of myoepithelial and immune cell biomarkers on 219 DCIS lesions from 30 cases. Notably, the majority of pure (low-risk) DCIS lesions clustered in a high calponin-1, T cell low group, whereas the majority of mixed (high-risk) DCIS lesions clustered in a low calponin-1, T cell high group, specifically with CD8+ and PD-1+CD8+ T cells. However, a subset of pure DCIS lesions had a similar calponin-1 and immune signature as the majority of mixed DCIS lesions, which have low calponin-1 and T cell enrichment-raising the possibility that these pure DCIS lesions might be at a high risk for progression.

Comparison of Mortality Among Participants of Women's Health Initiative Trials With Screening-Detected Breast Cancers vs Interval Breast Cancers

IMPORTANCE

Interval breast cancers (IBCs) are cancers that emerge after a mammogram with negative results but before the patient's next scheduled screening. Interval breast cancer has a worse prognosis than cancers detected by screening; however, it is unknown whether the length of the interscreening period is associated with prognostic features and mortality.

OBJECTIVE

To compare the prognostic features and mortality rate of women with IBCs diagnosed within 1 year or between 1 and 2.5 years of a mammogram with negative results with the prognostic features and mortality rate of women with breast cancers detected by screening.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used mammography data, tumor characteristics, and patient demographic data from the Women's Health Initiative study, which recruited participants from 1993 to 1998 and followed up with participants for a median of 19 years. The present study sample for these analyses included women aged 50 to 79 years who participated in the Women's Health Initiative study and includes data collected through March 31, 2018. There were 5455 incidents of breast cancer; only 3019 women compliant with screening were retained in analyses. Statistical analysis was performed from October 25, 2018, to November 24, 2019. Breast cancers detected by screening and IBCs were defined based on mammogram history, date of last mammogram, type of visit, and results of examination. Interval breast cancers were subdivided into those occurring within 1 year or between 1 and 2.5 years after the last protocol-mandated mammogram with negative results.

MAIN OUTCOMES AND MEASURES

The primary outcome of this study was breast cancer-specific mortality for each case of breast cancer detected by screening and IBCs detected within 1 year or between 1 and 2.5 years from a mammogram with negative results. Secondary outcomes included prognostic and tumor characteristics for each group. Comparisons between groups were made using the t test, the χ2 test, and Fine-Gray multivariable cumulative incidence regression analyses.

RESULTS

Among the 3019 participants in this analysis, all were women with a mean (SD) age of 63.1 (6.8) years at enrollment and 68.5 (7.1) years at diagnosis. A total of 1050 cases of IBC were identified, with 324 (30.9%) diagnosed within 1 year from a mammogram with negative results and 726 (69.1%) diagnosed between 1 and 2.5 years after last mammogram with negative results. The remaining 1969 cases were breast cancers detected by screening. Interval breast cancers diagnosed within 1 year from a mammogram with negative results had significantly more lobular histologic characteristics (13.0% vs. 8.1%), a larger tumor size (1.97 cm vs 1.43 cm), a higher clinical stage (28.4% vs 17.3% regional and 3.7% vs 0.6% distant), and more lymph node involvement (27.1% vs 17.0%) than cancers detected by screening. Unadjusted breast cancer-specific mortality hazard ratios were significantly higher for IBCs diagnosed within 1 year from a mammogram with negative results compared with breast cancers detected by screening (hazard ratio, 1.92; 95% CI, 1.39-2.65). Higher breast cancer-specific mortality remained statistically significant for IBCs diagnosed within 1 year after adjusting for trial group, molecular subtype, waist to hip ratio, histologic characteristics, and either tumor size (hazard ratio, 1.46; 95% CI, 1.03-2.08) or lymph node involvement (hazard ratio, 1.44; 95% CI, 1.03-2.01). However, significance was lost when tumor size and lymph node involvement were both included in the model (hazard ratio, 1.34; 95% CI, 0.96-1.88). Interval breast cancers diagnosed between 1 and 2.5 years from a mammogram with negative results were not different from breast cancers detected by screening based on prognostic factors or mortality.

CONCLUSIONS AND RELEVANCE

Women with IBCs diagnosed within 1 year of negative mammogram results overall were associated with worse survival than women with breast cancers detected by screening. These differences in survival may be due to a uniquely aggressive biology among IBC cases.

RNA-seq from archival FFPE breast cancer samples: molecular pathway fidelity and novel discovery

BACKGROUND

Formalin-fixed, paraffin-embedded (FFPE) tissues for RNA-seq have advantages over fresh frozen tissue including abundance and availability, connection to rich clinical data, and association with patient outcomes. However, FFPE-derived RNA is highly degraded and chemically modified, which impacts its utility as a faithful source for biological inquiry.

METHODS

True archival FFPE breast cancer cases (n = 58), stored at room temperature for 2-23 years, were utilized to identify key steps in tissue selection, RNA isolation, and library choice. Gene expression fidelity was evaluated by comparing FFPE data to public data obtained from fresh tissues, and by employing single-gene, gene set and transcription network-based regulon analyses.

RESULTS

We report a single 10 μm section of breast tissue yields sufficient RNA for RNA-seq, and a relationship between RNA quality and block age that was not linear. We find single-gene analysis is limiting with FFPE tissues, while targeted gene set approaches effectively distinguish ER+ from ER- breast cancers. Novel utilization of regulon analysis identified the transcription factor KDM4B to associate with ER+ disease, with KDM4B regulon activity and gene expression having prognostic significance in an independent cohort of ER+ cases.

CONCLUSION

Our results, which outline a robust FFPE-RNA-seq pipeline for broad use, support utilizing FFPE tissues to address key questions in the breast cancer field, including the delineation between indolent and life-threatening disease, biological stratification and molecular mechanisms of treatment resistance.

A way forward for cancer prevention therapy: personalized risk assessment

Cancer is characterized by genetic and molecular aberrations whose number and complexity increase dramatically as cells progress along the spectrum of carcinogenesis. The pharmacologic application of agents in the context of a lower burden of dysregulated cellular processes constitutes an efficient strategy to enhance therapeutic efficacy, and underlies the rationale for using cancer prevention agents in high-risk populations. A longstanding barrier to implementing this strategy is that the risk in the general population is low for any given cancer, many people would have to be treated in order to benefit a few. Therefore, identifying and treating high-risk individuals will improve the risk: benefit ratio. Currently, risk is defined by considering a relatively low number of factors. A strategy that considers multiple factors has the ability to define a much-higher-risk cohort than the general population. This article will review the rationale for evaluating multiple risk factors so as to identify individuals at highest risk. It will use breast and lung cancer as examples, will describe currently available risk assessment tools, and will discuss ongoing efforts to expand the impact of this approach. The high potential of this strategy to provide a way forward for developing cancer prevention therapy will be highlighted.

Abstract LB-140: Myoepithelial-immune cell crosstalk in the transition from non-invasive to invasive breast cancer

The incidence of ductal carcinoma in situ (DCIS), a pre-invasive malignancy of the breast, has increased in the U.S. since the 1980s, from 3% to 20% of all breast cancer diagnoses. This increase is largely attributed to mammographic screening. Common treatments of DCIS are breast-conserving surgery followed by adjuvant radiation therapy or mastectomy. Further, despite efforts to detect and treat early stage cancer, the incidence of invasive breast cancer (IBC) has not declined, suggesting that many women with DCIS are over treated. Thus, prognostic markers that predict risk of DCIS progression are needed. Genomic studies have yet to find tumor intrinsic alterations that predict DCIS progression to IBC. In contrast, genetic changes in the myoepithelium are found at the transition from DCIS to IBC, suggesting myoepithelial cells may play a role in progression. To investigate the myoepithelium for potential biomarkers, we advanced a non-surgical intraductal tumor cell delivery model in mice using human DCIS.com cells. We reported a progressive loss in myoepithelial differentiation markers p63, calponin, and smooth muscle actin (SMA) prior to transition to IBC, observations that were confirmed in human DCIS. Thus, compromise in the myoepithelium may be an early warning for DCIS at high risk for progression. Here, we hypothesize that the myoepithelial differentiation state informs immune response, and that DCIS lesions with loss of myoepithelial Calponin and SMA will be associated with a pro-tumorigenic immune milieu. This hypothesis is based on observations by us and others showing lymphocyte infiltration in areas where the DCIS myoepithelium has been focally compromised. To address this, we analyzed the expression of 10 myoepithelial and lymphoid biomarkers using multiplex immunohistochemistry to analyze the relationship between myoepithelial cell integrity and immune cells (N=36 cases). DCIS in the background of IBC (mixed DCIS) is assumed to be high-risk DCIS. We find compromised myoepithelial calponin in mixed compared to pure DCIS. Mixed lesions also show reduced infiltration of immune and T-cells, consistent with reduced immune surveillance. However, calponin loss in pure DCIS cases was associated with a decrease in Foxp3+ T-regulatory cells and increase in CD8+PD-1+ T-cells. Next we found that DCIS areas with focal loss of the myoepithelium and micro-invasion showed an increase in immune infiltration, increased T-cells, and increased PD-1+CD8+ T-cells. These data suggest that early compromise in the myoepithelial layer may associate with activation of cytotoxic effectors, consistent with increased immune surveillance. However, since we find T-cell numbers are reduced in mixed DCIS, effective immune surveillance may be dampened with progression. These data support an unreported relationship between myoepithelial cell integrity and the activation state of local immune cells.

Citation Format: Elizabeth Mitchell, Sonali Jindal, Tiffany Chan, Jayasri Narasimhan, Sheila Weinmann, Pepper Schedin. Myoepithelial-immune cell crosstalk in the transition from non-invasive to invasive breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr LB-140.

Association of p53 expression with poor prognosis in patients with triple-negative breast invasive ductal carcinoma

TP53 gene is mutated in approximately 80% of triple-negative breast cancer (TNBC). However, the prognostic significance of immunohistochemical (IHC)-detected p53 protein expression remains controversial in TNBC. In this study, we retrospectively analyzed the association between IHC-detected p53 expression and the prognosis in a cohort of 278 patients with stage I-III triple-negative breast invasive ductal carcinoma (IDC), who received surgery at the department of breast surgery in the Fourth Hospital of Hebei Medical University from 2010-01 to 2012-12. We found a positive expression ratio of IHC-detected p53 in triple-negative breast IDC of 58.6% (163/278). Furthermore, levels of expression were significantly associated with vessel tumor emboli and higher histologic grade (P = .038, P = .043, respectively), with the highest expression level observed in G3 breast cancer (64.7%). Additionally, Kaplan-Meier analysis showed that p53 expression indicated worse overall survival (OS) in the whole cohort (79.6% vs 89.6%, Log-rank test P = .025) as well as in stratified prognostic stage II patients (90.8% vs 100%, Log-rank test P = .027). The mortality risk of p53 expression patients was 2.22 times higher than that of p53 negative patients (HR: 2.222; 95%CI: 1.147-4.308). In addition, p53 expression was also associated with poor disease-free survival (DFS) (76.7% vs 86.8%, P = .020). Cox proportional hazard ratio model showed p53 expression was an independent risk factor for OS (P = .018) and DFS (P = .018) after controlling for tumor size, lymph node status, and vessel tumor emboli. Altogether, our data showed that IHC-detected p53 expression is a promising prognostic candidate for poor survival in triple-negative breast IDC patients. However, more studies are needed to determine if p53 may be applied to clinical practice as a biomarker and/or novel therapeutic target for TNBC.

INFRASTRUCTURE, RESOURCES, SERVICES EVALUATION AND GAP ANALYSIS OF INTEGRATED MATERNAL AND CHILD DEVELOPMENT SERVICES IN INDIA

Background. Integrated Child Development Services (ICDS) is an Indian community-centric government program organized under Anganwadi centres catering to supplementary nutrition, health and preschool education, primary healthcare, growth monitoring and counselling the children under six years old along with their mothers. It is the world’s largest outreach program in a developing country covering a population of 1.35 billion; the variations in service delivery were analysed involving cross-sectional rural and urban Anganwadi centers in New Delhi. Methods. Data were collected by assessment of children and mothers, interview of Anganwadi workers and observation of service delivery parameters and conduction of activities. Infrastructural, beneficiaries, services and content were evaluated by a suitable pre-tested questionnaire based on the National Institute of Public Cooperation and Child Development (NIPCCD) evaluation proforma. The data was analysed by a descriptive statistics. Results. Gaps were found in respect of infrastructure, resources, health and nutrition facilities especially at rural Anganwadi centre which was inadequate in terms of implementation of nutrition and health program, supplementary nutrition, preschool education and nutrition rehabilitation centre for existing beneficiaries. Both Anganwadi centres were not catering for new WHO growth standards and adolescent health. Conclusions. Gaps found in respect of infrastructure, resources, health and nutrition facilities can affect performance of ICDS program and the services delivered by Anganwadi centres, which need a boost. Both urban and rural centres have a direct opportunity towards delivering adolescent health program focusing on nutrition and education of girls prior to their pregnancy, and adoption of new WHO growth standards.

Association Between Postpartum Breast Cancer Diagnosis and Metastasis and the Clinical Features Underlying Risk

IMPORTANCE

In women 45 years or younger, breast cancer diagnosis after childbirth increases the risk for metastasis and death, yet limited data exist to define this window of risk and associated prognostic factors.

OBJECTIVE

To assess the window of elevated risk for metastasis following a postpartum breast cancer (PPBC) diagnosis and whether clinical prognostic factors are associated with the increased risk.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter cohort study conducted using cases from the Colorado Young Women's Breast Cancer Cohort diagnosed between January 1, 1981, and December 31, 2014, included 701 women 45 years or younger with stage I to III invasive breast cancer for whom parity data, including time of last childbirth, were available. Data analysis was conducted from July 1 to September 30, 2017. This study involved a tertiary care academic hospital-based breast center and its regional affiliates with cases from the greater Rocky Mountain region.

EXPOSURES

Primary exposures were prior childbirth or no childbirth, time between most recent childbirth and breast cancer diagnosis, and time between breast cancer diagnosis and metastasis.

MAIN OUTCOMES AND MEASURES

The primary outcome was distant metastasis-free survival.

RESULTS

A total of 701 women 45 years or younger from the greater Rocky Mountain states region were included in the analysis; mean (SD) age at diagnosis was 37.9 (5.1) years. Breast cancer diagnosis within 10 years after parturition was associated with elevated risk for metastasis, particularly in women with stage I or II disease. In addition, women with PPBC diagnosed within 10 years of a completed pregnancy that was estrogen receptor-positive showed distant metastasis-free survival similar to that of nulliparous patients with estrogen receptor-negative cancer, and women with estrogen receptor-negative PPBC had further reduced metastasis-free survival. Moreover, women with PPBC had increased lymphovascular invasion and lymph node involvement. In addition, tumor-associated Ki67 positivity identified 129 patients with luminal B cancer in the cohort that, independent of parity status, had poorer prognosis compared with patients with luminal A cancer, although it did not reach statistical significance.

CONCLUSIONS AND RELEVANCE

Diagnosis of PPBC within 10 years post partum appears to be associated with an increased risk for metastasis. This increased risk was highest in stages I and II cancer at diagnosis and present in both patients with estrogen receptor-positive and estrogen receptor-negative cancer, persisting in estrogen receptor-positive cases for up to 15 years after diagnosis. Postpartum breast cancer diagnoses were not associated with increased Ki67 index but were associated with increased lymphovascular invasion and lymph node involvement compared with breast cancer in nulliparous patients.

Ibuprofen supports macrophage differentiation, T cell recruitment, and tumor suppression in a model of postpartum breast cancer

BACKGROUND

Women diagnosed with breast cancer within 5 years postpartum (PPBC) have poorer prognosis than age matched nulliparous women, even after controlling for clinical variables known to impact disease outcomes. Through rodent modeling, the poor prognosis of PPBC has been attributed to physiologic mammary gland involution, which shapes a tumor promotional microenvironment through induction of wound-healing-like programs including myeloid cell recruitment. Previous studies utilizing immune compromised mice have shown that blocking prostaglandin synthesis reduces PPBC tumor progression in a tumor cell extrinsic manner. Given the reported roles of prostaglandins in myeloid and T cell biology, and the established importance of these immune cell populations in dictating tumor growth, we investigate the impact of involution on shaping the tumor immune milieu and its mitigation by ibuprofen in immune competent hosts.

METHODS

In a syngeneic (D2A1) orthotopic Balb/c mouse model of PPBC, we characterized the impact of mammary gland involution and ibuprofen treatment on the immune milieu in tumors and draining lymph nodes utilizing flow cytometry, multiplex IHC, lipid mass spectroscopy and cytokine arrays. To further investigate the impact of ibuprofen on programming myeloid cell populations, we performed RNA-Seq on in vivo derived mammary myeloid cells from ibuprofen treated and untreated involution group mice. Further, we examined direct effects of ibuprofen through in vitro bone marrow derived myeloid cell cultures.

RESULTS

Tumors implanted into the mammary involution microenvironment grow more rapidly and display a distinct immune milieu compared to tumors implanted into glands of nulliparous mice. This milieu is characterized by increased presence of immature monocytes and reduced numbers of T cells and is reversed upon ibuprofen treatment. Further, ibuprofen treatment enhances Th1 associated cytokines as well as promotes tumor border accumulation of T cells. Safety studies demonstrate ibuprofen does not impede gland involution, impact subsequent reproductive success, nor promote auto-reactivity as detected through auto-antibody and naïve T cell priming assays.

CONCLUSIONS

Ibuprofen administration during the tumor promotional microenvironment of the involuting mammary gland reduces overall tumor growth and enhances anti-tumor immune characteristics while avoiding adverse autoimmune reactions. In sum, these studies implicate beneficial prophylactic use of ibuprofen during the pro-tumorigenic window of mammary gland involution.

Abstract SY38-02: Postpartum tissue remodeling drives breast cancer metastasis

Women diagnosed with breast cancer within 10 years of a completed pregnancy are at ~2-3 fold increased risk for developing metastatic disease (1,2). This increased risk for metastasis is independent of tumor stage and biologic subtype, implicating a tumor-extrinsic biology unique to the postpartum woman (3,4). Further, 30-50% of all young women diagnosed with breast cancer have had a completed pregnancy within the last 10 years (4), making a postpartum diagnosis an independent poor prognostic indicator for a significant number of patients. One postpartum event that may drive tumor progression in rodents (5-8) and women (9) is weaning-induced mammary gland involution, a physiologic tissue remodeling process that shares numerous attributes with protumorigenic wound healing. We have developed rodent models designed to mimic this highly metastatic subset of young women's breast cancer and find that weaning-induced mammary gland involution supports breast cancer growth, dissemination, and escape to secondary organs in a COX-2 dependent manner (6,10,11). Here we extend these studies by investigating the mammary gland from a mucosal organ perspective, as identifying links with mucosal biology and its associated immune suppression may provide insight into the poor prognosis of postpartum breast cancers. While the mammary gland is not classically considered a mucosal organ, bacteria routinely interface with luminal epithelium during lactation, necessitating barrier function. Similar barrier defenses are anticipated during weaning-induced mammary gland involution, as milk stasis increases risk for mastitis. One key immunologic hallmark of a mucosal organ is the presence of a distinct CD4+ helper T-cell subset, Th17 cells. Th17 cells stimulate epithelial cell junction integrity and epithelial secretion of mucins and defensins, mechanisms that barricade against bacterial activation of antitumor Th1 immune cells. Within the mammary gland we find a baseline mucosal program of Th17 T cells, which is elevated within lactating and involuting mammary glands. Mucosal features are further expanded during involution to include tolerogenic dendritic cell phenotypes, barrier-supportive antimicrobials, alternatively activated Th2 CD4+ cells, and immunosuppressive Treg CD4+T cells. Further, during involution, we find suppression of mammary-derived antigen-dependent CD4+ T-cell activation, data consistent with immune tolerance. We also find antigen-independent accumulation of memory Th17- Treg CD4+ T cells, data consistent with weaning-induced mammary inflammation. Overall, these data elucidate strong mucosal immune programs within the lactating gland and immune-suppressive programs within the involuting gland. Tumor cells within the involution immunologic microenvironment are anticipated to avoid immune detection and readily escape the mammary gland, a mechanism that may contribute to increased metastasis observed in postpartum breast cancer patients. Importantly, to successfully metastasize, a tumor cell must not only escape from the primary tumor, but also seed and grow within the secondary site. Thus, an additional potential mechanism by which a postpartum diagnosis may confer increased risk of metastasis is through involution-specific changes at metastatic sites. We report evidence for such a metastatic advantage within the liver of postpartum hosts. Using both intracardiac and portal vein liver metastasis models, we find that the post-weaning liver supports increased seeding of murine mammary tumor cells compared to livers of nulliparous control mice (12). Relevance to women is suggested by data obtained from a cohort of young women's breast cancer patients, where liver metastatic tropism is observed specifically in postpartum patients. In rodents, the biology driving this metastatic advantage is weaning-induced liver involution, a previously unrecognized tissue remodeling process. Post weaning, we find a 50% reduction in liver volume, hepatocyte cell death, deposition of fibrillar collagen and tenascin-c, increased matrix metalloproteinase activity, and influxes of immune cell populations with immune-suppressive phenotypes (12,13). These tissue-level changes are consistent with the establishment of a prometastatic niche during liver involution. Combined, our studies are supportive of the mammary gland being a hormone-responsive, immune-suppressed mucosal organ, and suggest the liver as a hormone-responsive organ that is functionally coordinated with the mammary gland during the cycle of pregnancy, lactation, and weaning. Further, we identify stromal remodeling in the mammary gland and liver as a mediator of breast cancer metastasis in the postpartum window. These findings shed light on how normal reproductive physiology, specifically mucosal biology interfaced with tissue remodeling, alters site-specific metastasis. These findings provide the framework necessary to investigate postpartum involution as a target for the prevention of breast cancer metastasis in young women.References:

1. Johansson AL et al. Increased mortality in women with breast cancer detected during pregnancy and different periods postpartum. Cancer Epidemiol Biomarkers Prev 2011;20(9):1865-72.

2. Lambe M et al. Transient increase in the risk of breast cancer after giving birth. N Engl J Med 1994;331(1):5-9.

3. Schedin P. Pregnancy-associated breast cancer and metastasis. Nat Rev Cancer 2006;6(4):281-91.

4. Callihan EB et al. Postpartum diagnosis demonstrates a high risk for metastasis and merits an expanded definition of pregnancy-associated breast cancer. Breast Cancer Res Treat 2013;138(2):549-59.

5. Guo Q et al. Physiologically activated mammary fibroblasts promote postpartum mammary cancer. JCI Insight 2017;2(6):e89206.

6. Martinson HA et al. Wound healing-like immune program facilitates postpartum mammary gland involution and tumor progression. Int J Cancer 2015;136(8):1803-13.

7. McDaniel SM et al. Remodeling of the mammary microenvironment after lactation promotes breast tumor cell metastasis. Am J Pathol 2006;168(2):608-20.

8. O'Brien J et al. Alternatively activated macrophages and collagen remodeling characterize the postpartum involuting mammary gland across species. Am J Pathol 2010;176(3):1241-55.

9. Jindal S et al. Postpartum breast involution reveals regression of secretory lobules mediated by tissue-remodeling. Breast Cancer Res 2014;16(2):R31.

10. Lyons TR et al. Cyclooxygenase-2-dependent lymphangiogenesis promotes nodal metastasis of postpartum breast cancer. J Clin Invest 2014;124(9):3901-12.

11. Lyons TR et al. Postpartum mammary gland involution drives progression of ductal carcinoma in situ through collagen and COX-2. Nat Med 2011;17(9):1109-15.

12. Goddard ET et al. The rodent liver undergoes weaning-induced involution and supports breast cancer metastasis. Cancer Discov 2017;7(2):177-87.

13. Goddard ET et al. Quantitative extracellular matrix proteomics to study mammary and liver tissue microenvironments. Int J Biochem Cell Biol 2016;81(Pt A):223-32.

Citation Format: Courtney Betts, Nathan Pennock, Erica Goddard, Qiuchen Guo, Sonali Jindal, Virginia F. Borges, Pepper Jo Schedin, Alex Quackenbush. Postpartum tissue remodeling drives breast cancer metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr SY38-02.

Metformin inhibits stromal aromatase expression and tumor progression in a rodent model of postmenopausal breast cancer

BACKGROUND

Obesity and type II diabetes are linked to increased breast cancer risk in postmenopausal women. Patients treated with the antidiabetic drug metformin for diabetes or metabolic syndrome have reduced breast cancer risk, a greater pathologic complete response to neoadjuvant therapy, and improved breast cancer survival. We hypothesized that metformin may be especially effective when targeted to the menopausal transition, as this is a lifecycle window when weight gain and metabolic syndrome increase, and is also when the risk for obesity-related breast cancer increases.

METHODS

Here, we used an 1-methyl-1-nitrosourea (MNU)-induced mammary tumor rat model of estrogen receptor (ER)-positive postmenopausal breast cancer to evaluate the long-term effects of metformin administration on metabolic and tumor endpoints. In this model, ovariectomy (OVX) induces rapid weight gain, and an impaired whole-body response to excess calories contributes to increased tumor glucose uptake and increased tumor proliferation. Metformin treatment was initiated in tumor-bearing animals immediately prior to OVX and maintained for the duration of the study.

RESULTS

Metformin decreased the size of existing mammary tumors and inhibited new tumor formation without changing body weight or adiposity. Decreased lipid accumulation in the livers of metformin-treated animals supports the ability of metformin to improve overall metabolic health. We also found a decrease in the number of aromatase-positive, CD68-positive macrophages within the tumor microenvironment, suggesting that metformin targets the immune microenvironment in addition to improving whole-body metabolism.

CONCLUSIONS

These findings suggest that peri-menopause/menopause represents a unique window of time during which metformin may be highly effective in women with established, or at high risk for developing, breast cancer.

A METHOD FOR QUANTIFICATION OF CALPONIN EXPRESSION IN MYOEPITHELIAL CELLS IN IMMUNOHISTOCHEMICAL IMAGES OF DUCTAL CARCINOMA IN SITU

Ductal carcinoma in situ (DCIS) is breast cancer confined within mammary ducts, surrounded by an intact myoepithelial cell layer that prevents local invasion. A DCIS diagnosis confers increased lifetime risk of developing invasive breast cancer (IBC) and results in surgical excision with radiation, and possibly endocrine- or chemo-therapy. DCIS is known to be over treated, with associated co-morbidities. Biomarkers are needed that delineate patients at low risk of DCIS progression from patients requiring more aggressive treatment. Investigating the role of myoepithelial cell differentiation in barrier function is anticipated to provide insight into DCIS progression and delineate between low and high risk lesions. Here, we develop a high throughput technique to assess loss of myoepithelial differentiation markers. This method facilitates automated analysis of a clinically relevant histopathologic feature, as demonstrated by a high correlation with pathologist annotation (r = 0.959), and further, contributes analytical foundations to a multiplexed immunohistochemistry (IHC) approach.

Bilateral Asymmetrical Fracture Dislocation of Shoulder with Rare Combination of Injuries after Epileptic Seizure: A Case Report

The incidence of bilateral gleno-humeral joint dislocation is rare, is almost always posterior and is usually caused by sports injuries, epileptic seizures, electrical shock, or electroconvulsive therapy. Bilateral fracture-dislocation is even rarer, with a few cases reported in the literature. We report an unusual case with dislocation of the both glenohumeral joints in opposite direction after a seizure episode, with fracture of greater tuberosity on one side and of the lesser tuberosity on the contralateral side. Although there have been a few reports of bilateral asymmetric fracture dislocations of the shoulder in the past, an injury pattern resembling our case has, to the best of our knowledge, not been described in the literature so far. This report includes a detailed discussion regarding the mechanism of injury in a case of asymmetrical dislocation following a seizure episode. At final follow-up, the patient had healed fractures, painless near normal range of motion with no redislocations.

Myoepithelial cells in lobular carcinoma in situ: distribution and immunophenotype

Myoepithelial cells have important physical and paracrine roles in breast tissue development, maintenance, and tumor suppression. Recent molecular and immunohistochemical studies have demonstrated phenotypic alterations in ductal carcinoma in situ-associated myoepithelial cells. Although the relationship of lobular carcinoma in situ (LCIS) and myoepithelial cells was described in 1980, further characterization of LCIS-associated myoepithelial cells is lacking. We stained 27 breast specimens harboring abundant LCIS with antibodies to smooth muscle myosin heavy chain, smooth muscle actin, and calponin. Dual stains for E-cadherin/smooth muscle myosin heavy chain and CK7/p63 were also performed. In each case, the intensity and distribution of staining in LCIS-associated myoepithelial cells were compared with normal breast tissue on the same slide. In 78% of the cases, LCIS-associated myoepithelial cells demonstrated decreased staining intensity for one or more myoepithelial markers. The normal localization of myoepithelial cells (flat against the basement membrane, pattern N) was seen in 96% of LCIS, yet 85% of cases had areas with myoepithelial cell cytoplasm oriented perpendicular to the basement membrane (pattern P), and in 30% of cases, myoepithelial cells appeared focally admixed with LCIS cells (pattern C). This study characterizes detailed architectural and immunophenotypic alterations of LCIS-associated myoepithelial cells. The finding of variably diminished staining favors application of several myoepithelial immunostains in clinical practice. The interaction of LCIS with myoepithelial cells, especially in light of the perpendicular and central architectural arrangements, deserves further mechanistic investigation.

Myoepithelial cell differentiation markers in ductal carcinoma in situ progression

We describe a preclinical model that investigates progression of early-stage ductal carcinoma in situ (DCIS) and report that compromised myoepithelial cell differentiation occurs before transition to invasive disease. Human breast cancer MCF10DCIS.com cells were delivered into the mouse mammary teat by intraductal injection in the absence of surgical manipulations and accompanying wound-healing confounders. DCIS-like lesions developed throughout the mammary ducts with full representation of human DCIS histologic patterns. Tumor cells were incorporated into the normal mammary epithelium, developed ductal intraepithelial neoplasia and DCIS, and progressed to invasive carcinoma, suggesting the model provides a rigorous approach to study early stages of breast cancer progression. Mammary glands were evaluated for myoepithelium integrity with immunohistochemical assays. Progressive loss of the myoepithelial cell differentiation markers p63, calponin, and α-smooth muscle actin was observed in the mouse myoepithelium surrounding DCIS-involved ducts. p63 loss was an early indicator, calponin loss intermediate, and α-smooth muscle actin a later indicator of compromised myoepithelium. Loss of myoepithelial calponin was specifically associated with gain of the basal marker p63 in adjacent tumor cells. In single time point biopsies obtained from 16 women diagnosed with pure DCIS, a similar loss in myoepithelial cell markers was observed. These results suggest that further research is warranted into the role of myoepithelial cell p63 and calponin expression on DCIS progression to invasive disease.