Immune Phenotype and Postoperative Complications After Elective Surgery

OBJECTIVES

To characterize and quantify accumulating immunologic alterations, pre and postoperatively in patients undergoing elective surgical procedures.

BACKGROUND

Elective surgery is an anticipatable, controlled human injury. Although the human response to injury is generally stereotyped, individual variability exists. This makes surgical outcomes less predictable, even after standardized procedures, and may provoke complications in patients unable to compensate for their injury. One potential source of variation is found in immune cell maturation, with phenotypic changes dependent on an individual's unique, lifelong response to environmental antigens.

METHODS

We enrolled 248 patients in a prospective trial facilitating comprehensive biospecimen and clinical data collection in patients scheduled to undergo elective surgery. Peripheral blood was collected preoperatively, and immediately on return to the postanesthesia care unit. Postoperative complications that occurred within 30 days after surgery were captured.

RESULTS

As this was an elective surgical cohort, outcomes were generally favorable. With a median follow-up of 6 months, the overall survival at 30 days was 100%. However, 20.5% of the cohort experienced a postoperative complication (infection, readmission, or system dysfunction). We identified substantial heterogeneity of immune senescence and terminal differentiation phenotypes in surgical patients. More importantly, phenotypes indicating increased T-cell maturation and senescence were associated with postoperative complications and were evident preoperatively.

CONCLUSIONS

The baseline immune repertoire may define an immune signature of resilience to surgical injury and help predict risk for surgical complications.

How to Navigate the Treatment Spectrum from Multimodality Therapy to Observation Alone for ductal carcinoma in situ

DCIS detection has increased dramatically since the introduction of screening mammography. Current guidance concordant care recommends surgical intervention for all patients with DCIS, followed by radiation and/or endocrine therapy for some. Adjuvant therapies after surgical excision have reduced recurrence rates but not breast cancer mortality. Given the lack of evidence of current treatment regimens and the morbidity associated with these treatments, there is concern that DCIS is over-treated. Active surveillance may be a favorable alternative for selected patients and is currently being investigated through four international clinical trials.

Abstract B019: Discrete regulation of the collagen proteome among pathological features in DCIS and invasive breast cancer by mass spectrometry tissue imaging

Ductal carcinoma in situ (DCIS) is characterized by inter-tumor heterogeneity that poses a therapeutic challenge due to its unpredictable recurrence and progression to invasive breast cancer (IBC). In recent publications, collagen stromal differences have been reported between patients that progressed to IBC (progressors) and those that did not (non-progressors). However, details on the role spatial regulation of the collagen proteome might play in this progression have yet to be studied. Here, we investigated the pathological distribution of collagen post-translational modifications in a cohort of patients classified as progressors with ipsilateral IBC recurrence compared to non-progressors. Previously published methods for collagen proteomics by targeted tissue mass spectrometry imaging were used. The method reports collagen types and post-translational modifications within the collagen triple-helical region as well as approximately 40 other extracellular matrix (ECM) proteins involved in the regulation of collagen fibers. Initial studies investigated collagen variation in lumpectomies (n=7) with DCIS, DCIS plus invasive ductal carcinoma (IDC) or IDC only. Over 590 peptides were found to be linked to annotated pathologies. A preliminary comparison of DCIS (n=2392 spectra) to IBC (n=4696 spectra) using area under the receiver operating curve (AUROC) ≥0.85 demonstrated that 47 peptides could individually discriminate between DCIS and IBC in this limited cohort. Image segmentation of the 405,652 pixels demonstrated 11 high-level hierarchical groups designating unique spatially localized ECM proteomic groups; these groups overlaid with histopathological features and pathological annotations. A total of 87 samples from the Resource of Archival Breast Tissue (RAHBT) matched with clinical characteristics were also investigated. Cores were histologically diverse within the tissue microarrays, with cribriform, micropapillary, papillary, solid, and comedo necrosis architectural patterns. Initial results suggest certain peptides may differentiate between non-progressors and progressors with ipsilateral IBC recurrence. Our current work focuses on correlating collagen signatures to mixed pathologies and the cellular content of cores. Further investigation of the collagen proteome is warranted. Overall, the data suggest unique collagen signatures in DCIS that could be useful for understanding recurrence and progression to IBC.

Citation Format: Taylor S. Hulahan, Elizabeth N. Wallace, Siri H. Strand, Robert Michael Angelo, Graham Colditz, Eun-Sil Shelley Hwang, Robert West, Laura Spruill, Jeffrey R. Marks, Richard R. Drake, Peggi M. Angel. Discrete regulation of the collagen proteome among pathological features in DCIS and invasive breast cancer by mass spectrometry tissue imaging [abstract]. In: Proceedings of the AACR Special Conference on Rethinking DCIS: An Opportunity for Prevention?; 2022 Sep 8-11; Philadelphia, PA. Philadelphia (PA): AACR; Can Prev Res 2022;15(12 Suppl_1): Abstract nr B019.

Adaptive stress response genes associated with breast cancer subtypes and survival outcomes reveal race-related differences

Aggressive breast cancer variants, like triple negative and inflammatory breast cancer, contribute to disparities in survival and clinical outcomes among African American (AA) patients compared to White (W) patients. We previously identified the dominant role of anti-apoptotic protein XIAP in regulating tumor cell adaptive stress response (ASR) that promotes a hyperproliferative, drug resistant phenotype. Using The Cancer Genome Atlas (TCGA), we identified 46–88 ASR genes that are differentially expressed (2-fold-change and adjusted p-value < 0.05) depending on PAM50 breast cancer subtype. On average, 20% of all 226 ASR genes exhibited race-related differential expression. These genes were functionally relevant in cell cycle, DNA damage response, signal transduction, and regulation of cell death-related processes. Moreover, 23% of the differentially expressed ASR genes were associated with AA and/or W breast cancer patient survival. These identified genes represent potential therapeutic targets to improve breast cancer outcomes and mitigate associated health disparities.

Comparing an operation to monitoring, with or without endocrine therapy (COMET), for low-risk ductal carcinoma in situ (DCIS)

TPS616

Background: Approximately 50,000 women in the U.S. are diagnosed with ductal carcinoma in situ (DCIS) each year. Without treatment, it is estimated that only 20-30% of DCIS will lead to invasive breast cancer (IBC). However, over 97% of women are currently treated with surgery +/- radiation. An alternative to surgery is active monitoring (AM), a management approach in which mammograms/physical exams are used to monitor breast changes and determine when, or if, surgery is needed. The COMET Study will compare risks and benefits of AM versus surgery for low-risk DCIS in the setting of a Phase III multicenter prospective randomized trial. The study is funded by the Patient-Centered Outcomes Research Institute. The COMET trial opened in the U.S. in June 2017 (Clinicaltrials.gov reference: NCT02926911). In November 2021, the Data Safety Monitoring Board reviewed the trial and suggested that it continue as planned. Patient accrual will continue until 12/31/2022. Methods: The primary objective is to assess whether the 2-year ipsilateral IBC rate for AM is non-inferior to that for surgery. Secondary objectives include determining whether AM is non-inferior to surgery for 2-year mastectomy rate; breast conservation rate; contralateral breast cancer rate; overall and breast cancer-specific survival. Patient reported outcomes will enable comparison of health-related quality of life and psychosocial outcomes between surgery and AM groups at baseline, 6-months, and years 1-5. Eligibility criteria include: age > 40 at diagnosis; pathologic confirmation of grade I/II DCIS or atypia verging on DCIS without invasion by two pathologists; ER and/or PR ≥ 10%; no mass on physical exam or imaging. The accrual goal is 1200 randomized patients across 100 Alliance for Clinical Trials in Oncology sites. Sample size is estimated using a 2-group test of non-inferiority of proportions, with the 2-year IBC rate in the surgery group assumed to be 0.10 based on published studies and non-inferiority margin of 0.05. Based on a 1-sided un-pooled z-test, with alpha = 0.05, a sample size of n = 446 per group will have 80% power to detect the specified non-inferiority margin. Final analysis plan will include a per protocol component as well as a pragmatic component for patients who are randomized and decline participation in their assigned arm. Primary analyses will adjust for dropout, non-compliance and contamination by utilizing instrumental variable methods. Clinical trial information: NCT02926911.

Survival among patients with untreated metastatic breast cancer

1095

Background: Treatments for metastatic breast cancer (MBC) have significantly improved survival for patients who receive treatment, yet data describing the prognosis for untreated patients is lacking. Therefore, we sought to assess the survival outcomes of patients with de novo MBC who did not receive treatment. Methods: Adults with MBC at diagnosis (clinical M1 or pathologic M1) were selected from the NCDB (2010-2016) and stratified based on receipt of treatment (treated = received at least one treatment; untreated = received no treatments). Differences between patient groups were tested using Chi-square tests for categorical variables and t-tests for continuous variables. Overall survival (OS) was estimated using the Kaplan-Meier method for the overall cohort and stratified by select patient and/or disease characteristics, and groups were compared with log-rank tests. Cox Proportional Hazards models were used to identify factors associated with OS in the untreated MBC subgroup. Results: Of the 53,240 patients with de novo MBC, the median age was 61y (IQR 52-71), and the majority had a comorbidity score of 0 (81.2%). Within this cohort, 49,040 (92.1%) received at least one treatment (treated) and 4,200 (7.9%) had no documented treatments (untreated). Untreated patients were more likely to be older (median 68y vs 61y, p < 0.001) and have higher comorbidity scores (p < 0.001). Patients with untreated MBC were more likely to have triple negative disease (17.8% vs 12.6%), and a higher disease burden (≥2 metastatic sites: 38.2% untreated vs 29.2% treated, p < 0.001). The median unadjusted OS in the untreated subgroup was 2.5mo vs 36.4mo in the treated subgroup (p < 0.001). For those who survived at least 1mo post-diagnosis, the median unadjusted OS in the untreated subgroup was 6.9mo vs 37.3mo in the treated subgroup (p < 0.001), which increased to 18.6mo and 40.3mo for those who survived at least 3mo post-diagnosis (p < 0.001). In the untreated population, unadjusted OS varied by breast cancer subtype (median 3.8mo for HR+/HER2-, vs 2.6mo for HER2+, vs 2.1mo for triple negative, p < 0.001) and number of metastatic sites (4.1mo for 1 site, vs 1.8mo for 2 sites, vs 1.1mo for 3 sites, vs 1.2mo for ≥4 sites, p < 0.001). After adjustment, variables associated with a worse OS in the untreated cohort included older age, higher comorbidity scores, higher tumor grade, and triple negative (vs HR+/HER2-) tumor subtype (all p < 0.05), while the number of metastatic sites was not associated with survival; these same findings were also noted when the analysis was limited to those who survived at least 1mo post-diagnosis. Conclusions: Patients with de novo MBC who do not receive treatment are more likely to be older, present with comorbid conditions, and have clinically aggressive disease. Similar to those who do receive treatment, survival in an untreated population is associated with select patient and disease characteristics. However, the prognosis for untreated MBC is dismal.

Disparities in surveillance imaging after breast conserving surgery for primary DCIS

6516

Background: Due to the elevated risk of ipsilateral invasive breast cancer (iIBC) after diagnosis with primary ductal carcinoma in situ (DCIS), professional guidelines recommend surveillance screening within 6-12 months (mo) after completion of initial local treatment and annually thereafter. To characterize adherence to these guidelines, we explored longitudinal patterns of utilization and factors associated with the use of surveillance imaging (mammography, MRI, ultrasound) for women with primary DCIS treated with breast conserving surgery (BCS) ± radiotherapy (RT) within 6 mo of diagnosis. Methods: A treatment-stratified random sample of patients diagnosed with screen-detected and biopsy-confirmed DCIS in 2008-15 was selected from 1,330 Commission on Cancer-accredited facilities (up to 20/site) in the US. All imaging exams coded as asymptomatic were collected from 6 mo up to 10 years (yr) post-diagnosis. Time was defined according to 12-mo long surveillance periods. To be included in a given surveillance period, women had to be alive and free of a new breast cancer diagnosis through the end of the period. Women were classified as “consistent” screeners if they had at least one surveillance screen during each period, for the first 5 yr post-treatment or until censoring, whichever occurred first. Repeated measures multivariable logistic regression with generalized estimating equations was used to model receipt of surveillance breast imaging over time. The model included clinical and socioeconomic features. Results: The final analytic cohort contained 12,559 women; 8,989 (71.6%) received RT after BCS. Median age was 60 yr (interquartile range: 52-69) and median follow-up was 5.6 yr (95% confidence interval [CI] 5.6-5.7). Among women who received BCS (instead of BCS+RT), 62.5% (79.7%) underwent surveillance imaging within 6-18 mo after diagnosis. 38.7% (54.0%) were categorized as “consistent” screeners. Compared to white women, Black women were less likely to receive surveillance screening after treatment for primary DCIS (odds ratio [OR] 0.85, 95% CI 0.77-0.94). Hispanic ethnicity had a similar association (OR 0.86, 95% CI 0.74-0.99) compared to non-Hispanic ethnicity. Women with private insurance, compared to government insurance, were more likely to receive screening (OR 1.20, 95% CI 1.11-1.30). Prognostic tumor features indicative of a higher risk of subsequent iIBC, including higher grade, presence of comedonecrosis, and hormone receptor-negative DCIS, were not associated with screening uptake. Conclusions: Despite guidelines recommending annual surveillance imaging, many women with primary DCIS do not undergo regular imaging after BCS. The findings from this US-based study suggest that disparities in screening uptake are associated with race/ethnicity and insurance status rather than prognostic tumor features.

Characterizing participants in the North Carolina Breast and Cervical Cancer Control Program (NC BCCCP): A review of 90,000 women

101

Background: Overall breast cancer mortality in the US has declined since 1990, but racial/ethnic disparities have worsened. Since 1992, NC BCCCP has provided free/low-cost breast cancer screening to underserved women as part of a national effort by the Centers for Disease Control and Prevention (CDC) to mitigate these disparities. We sought to characterize and evaluate benchmarks for this previously unstudied, state-level cohort. Methods: We identified women ≥18y who underwent their first breast cancer screening via NC BCCCP from 2009-2018. Univariate analysis was used to compare differences in timeline of care and rates of breast pathology (i.e., cancer or atypia) by race/ethnicity and age. Logistic and negative binomial regression were used to identify factors associated with cancer diagnosis and time from enrollment to diagnosis (TTD) and treatment (TTT), respectively. Results: 88,893 women with complete records were identified (median age 50y, IQR 44-56): 45.5% were Non-Hispanic (NH) white, 30.9% NH black, 19.5% Hispanic, 1.7% American Indian (AI), and 1.1% Asian. Overall participation peaked in 2012 but steadily increased among Hispanic women over time (p < 0.001). Breast pathology was diagnosed in 2,016 (2.3%) women, with rates ranging from 1% in Hispanic women to 2.7% in NH whites. After adjustment, Hispanic women were least likely (vs NH white women: OR 0.40; 95% CI 0.34-0.47) to be diagnosed with breast cancer. Median TTD was 19d and TTT was 33d, both within the CDC’s 60d standard. In univariate analyses, women < 50 had shorter TTD (median 18d vs 21d) and TTT (median 30d vs 35d) vs women ≥50 (both p < 0.01), and there were no significant differences by race/ethnicity or between women with atypia vs cancer. In multivariate models, however, older age and NH black race were associated with longer TTD and TTT. Conclusions: NC BCCCP meets national quality benchmarks for TTD and TTT. These data also highlight broader opportunities to achieve racial/ethnic parity and improve equity for breast cancer prevention. [Table: see text]

The effect of body mass index (BMI) on survival in patients with breast cancer and obesity-associated conditions

203

Background: Previous studies have demonstrated an association between body mass index (BMI) and survival after breast cancer diagnosis, but the direction and strength of this relationship is inconsistent. Comorbidities that are more common in patients who are obese (BMI≥30) – including diabetes (DM), hypertension (HTN), and hyperlipidemia (HLD) – are often conflated with obesity with regard to their effects on breast cancer outcomes. We sought to determine the effect of BMI on overall survival (OS) among women with breast cancer after controlling for obesity-associated conditions. Methods: Women≥18y diagnosed with stage 0-IV breast cancer at an academic institution from Jan 2014-Jul 2016 and with known BMI at diagnosis were identified. χ2 and ANOVA tests were used to compare intergroup differences. BMI was categorized as normal (<25), overweight (25-29.9), class 1 obesity (30-34.9), and class 2/3 obesity (≥35). Unadjusted OS by BMI class was estimated with the Kaplan-Meier method. Cox proportional hazards models were used to estimate the association of BMI with OS after adjusting for covariates including obesity-associated conditions. Results: 1027 patients were included (median follow-up 46.8 mos): 296 (28.9%) were overweight, 227 (22.1%) had class 1 obesity, and 207 (20.2%) had class 2/3 obesity. Non-Hispanic (NH) black women were overrepresented among obese patients, making up 25% (n=257) of all patients but 37.5% of obese patients. Rates of DM, HTN, and HLD increased with increasing BMI (all p<0.01). Unadjusted OS differed significantly by BMI class, with overweight women having the worst 5-year OS (log-rank p=0.02). After adjustment, BMI continued to be associated with OS, with overweight women having significantly worse OS vs normal-weight women, but there was no significant association between obesity and OS (Table). Conclusions: Despite higher rates of DM, HTN, and HLD with increasing BMI, a diagnosis of obesity was not associated with worse OS in women with breast cancer but being overweight was, suggesting the need for a more nuanced understanding of body composition, obesity-associated conditions, and their respective potential impact on breast cancer outcomes. [Table: see text]

Blocking pro-invasive signaling and inflammatory activation in triple-negative breast cancer with nucleic-acid scavengers (NASs)

e13096

Background: Breast cancers remain the most lethal malignancies amongst women worldwide and the second leading cause of cancer-related mortalities in the US. Subtype heterogeneity and aggressive invasive potential are believed to be the major contributors of these outcomes. Triple-negative breast cancer (TNBC) are notoriously aggressive, difficult-to-treat, and metastatic. Inflammation-driven tumorigenesis has been shown to correlate with cell-free DNA (cfDNA) and other damage-associated molecular patterns (DAMPs) in cancer patient sera. We showed that nucleic-acid scavengers (NAS) can block pro-inflammatory signals elicited by DAMP-activation of innate immune sensors (e.g. toll-like receptors). Treatment with the NAS PAMAM-G3 drastically reduced liver metastatic burden in an immunocompetent murine model of pancreatic cancer. Methods: TNBC cells lines were treated with a cocktail of standard-of-care chemotherapeutic agents and the conditioned media (CM) from these cells served as an in vitro DAMP source. Downstream function of TLR activation was tested via a HEK293-TLR reporter cell line measuring absorbance at 655nm. The in vitro invasive phenotype was tested and quantified using a Transwell-Matrigel invasion assay. Cytokine secretion was measured using a BioLegend cytokine array. Results: TNBC CM greatly increased TNBC cell invasion in vitro and that treatment with the NAS PAMAM-G3 significantly inhibits this effect. Treatment of human monocytes (THP-1) with TNBC CM elicited a strong pro-inflammatory response with elevated levels of IL-8, IL-6, CCL2, and IL-1β. Other biologically immune responders including human PBMCs will be tested to determine the potential impact on the tumor immune microenvironment during tumorigenesis and treatment. Conclusions: To elucidate the mechanism by which this NAS works in these tumor settings, our lab has developed several PAMAM-G3 derivatives, including biotin, IR-, and near-IR fluorophore labeled molecules. These molecules will allow us to capture and characterize DAMPs and do in vivo live imaging experiments to gain insight into NAS PK/PD properties. This insight into NAS capabilities will enhance our understanding of metastatic progression and its interplay with the immune system. Moreover, these principles will aid in the development of novel of anti-metastatic therapies to improve TNBC patient outcomes.

Ipsilateral invasive cancer risk after diagnosis with ductal carcinoma in situ (DCIS): Comparison of patients with and without index surgery

519

Background: Most women diagnosed with ductal carcinoma in situ (DCIS) undergo surgical resection, potentially leading to overtreatment of patients who would not develop clinically significant breast cancer in the absence of locoregional treatment. We compared the risk of ipsilateral invasive breast cancer (iIBC) between DCIS patients who received breast conserving surgery (BCS) for their index diagnosis of DCIS (BCS group) and patients who did not receive any locoregional treatment within 6 months of diagnosis (surveillance [SV] group). Methods: A treatment-stratified random sample of patients diagnosed with screen-detected and biopsy-confirmed DCIS in 2008-14 was selected from 1,330 Commission on Cancer-accredited facilities (20/site). Excluding patients who received a mastectomy ≤6 months, the final analytic cohort contained 14,245 (88.2%) BCS and 1,914 (11.8%) SV patients. Subsequent breast events were abstracted up to 10 years after diagnosis. Primary outcome was the 8-year absolute difference in iIBC risk between BCS and SV; a subgroup analysis was performed for grade I/II patients. A propensity score (PS) model for treatment was fitted with sampling design (SD) weighting and random effects for patients within facilities. Absolute risk differences were estimated using PS-SD-weighted Kaplan Meier estimators. Results: Overall, median age at diagnosis was 61 years (IQR: 52-69) and median follow-up was 5.8 years (95% CI 5.7-6.1). The majority of patients were Caucasian (81.9%), with estrogen receptor-positive (80.6%), and nuclear grade I/II (54.5%) DCIS. The fraction of patients with a Charlson comorbidity score of ≥2 was higher in SV (14.2%) compared to BCS (6.4%, p < 0.001). The 8-year risk of iIBC was 3.0% (95% CI: 2.4%-3.6%) for BCS and 7.7% (95% CI: 4.9%-10.5%) for SV, with an absolute risk difference of 4.7% (95% CI: 4.5%-4.9%; log-rank p < 0.001). Among patients with grade I/II tumors, the 8-year risk of iIBC was 3.1% (95% CI: 2.3%-4.0%) for BCS and 6.1% (95% CI: 2.5%-9.8%) for SV; difference: 3.0% (95% CI: 2.7%-3.2%; p = 0.005). Conclusions: Despite an increased risk of iIBC in SV patients compared to BCS patients, the 8-year risk did not exceed 10% in either group. The risk of recurrence in BCS patients was comparable to previously reported estimates. These data demonstrate a considerable degree of overtreatment among patients with non-high grade DCIS. Prospective clinical trials will help determine the tradeoffs between universally directed as opposed to selectively applied surgery for low risk DCIS.

Abstract P6-16-06: Improved early stratification of invasive cancer risk using MRI in a ductal carcinoma in-situ short-term active surveillance cohort treated with neoadjuvant endocrine therapy

Purpose

Standard treatment for ductal carcinoma in situ (DCIS) involves surgical excision and radiation treatment, and often adjuvant endocrine therapy (ET). However, this may constitute overtreatment for some women. The purpose of this neoadjuvant ET study in patients with biopsy-proven DCIS was to evaluate the relationship between the primary outcome of upstaging at surgery (invasive disease) and changes in the pre- and post-ET MRI appearances of both (1) lesion and (2) background parenchymal enhancement (BPE), with the goal to better inform de-escalated therapy.

Methods

Outcomes of patients with DCIS who were prospectively enrolled in a neoadjuvant ET trial between 2002 and 2009 were retrospectively analyzed with IRB approval. All patients had dynamic contrast-enhanced breast MRI prior to and following an average of 3.1 months of ET (range 1.9 – 5 months), followed by surgical excision within one year of the second MRI. Pathology reports were used to confirm initial biopsy results and to determine the nature and extent of disease postoperatively. Surgeon and radiologist’s reports were used to assess improvement of lesion after ET based on 1) less prominently enhancing pattern or 2) reduction in size of DCIS lesion after treatment. BPE response to ET on imaging was assessed by two radiologists specialized in breast imaging who compared pre- and post-ET MRI’s, blinded to all imaging reports. The change in BPE of the ipsilateral breast with treatment was scored subjectively as increased, decreased, or unchanged. Readers reached a consensus on discordant classifications of the change in BPE. The correlation between imaging change (of lesion and BPE) and incidence of invasive ductal carcinoma (IDC) at surgery was determined using Fisher’s exact test.

Results: Of 34 patients evaluated, six (18%) had IDC at surgery. The prevalence of IDC in each group is shown in Table 2. Those with improvement of lesion on MRI had a lower likelihood of IDC at surgery compared to patients with no imaging improvement (Table 2, p= 0.048). Addition of change in BPE to the evaluation of lesion improvement significantly increased the chance of identifying specific patients who were much more likely to have an underlying invasive cancer at surgery (Table 2, p= 0.032). The risk of having IDC at surgery was considerably higher in the group whose lesion was assessed as not improved and who had decreased BPE scores on MRI (Table 2, p= 0.018).

Conclusion: In our unique population of patients with mostly ER+ DCIS receiving pre-operative endocrine therapy, the combination of lack of lesion improvement and reduction in BPE score in blinded reads was significantly associated with the finding of invasive disease at surgical excision. This result may reflect the unmasking of a more aggressive lesion in those with underlying IDC and help identify patients with a higher likelihood of the presence of IDC at surgery. Although this study is small, it suggests that risk-stratifying patients with DCIS based on lesion and parenchymal imaging features associated with treatment response may aid in tailoring therapy for DCIS. We are testing this prospectively in an active surveillance cohort.

Table 1. Incidence of IDC at surgery depending on image features (n= 34)Improvement of lesion in MRINo Improvement of lesion in MRIP-value (Fisher’s Exact Test)& No Reduction in BPE& Reduction in BPE& No Reduction in BPE& Reduction in BPEIncidence of IDC at surgery (n)0204Incidence of Not IDC at surgery (n)121024%IDC at surgery when assessing lesion only (%)9.1%40%0.048*%IDC at surgery when assessing lesion AND BPE (%)0%16.7%0%50%0.032*%IDC at surgery when assessing lesion AND BPE (%)8.3%50%0.018*

Citation Format: Paul Kim, Heather I. Greenwood, Rita I. Freimanis, Gillian L Hirst, Megan Fischer-Colbrie, Jessica Gibbs, Nola M Hylton, Christina Yau, Eun-Sil Shelley Hwang, Laura J. Esserman, Rita A Mukhtar. Improved early stratification of invasive cancer risk using MRI in a ductal carcinoma in-situ short-term active surveillance cohort treated with neoadjuvant endocrine therapy [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-16-06.

Prediction of Upstaged Ductal Carcinoma In Situ Using Forced Labeling and Domain Adaptation

OBJECTIVE

The goal of this study is to use adjunctive classes to improve a predictive model whose performance is limited by the common problems of small numbers of primary cases, high feature dimensionality, and poor class separability. Specifically, our clinical task is to use mammographic features to predict whether ductal carcinoma in situ (DCIS) identified at needle core biopsy will be later upstaged or shown to contain invasive breast cancer.

METHODS

To improve the prediction of pure DCIS (negative) versus upstaged DCIS (positive) cases, this study considers the adjunctive roles of two related classes: atypical ductal hyperplasia (ADH), a non-cancer type of breast abnormity, and invasive ductal carcinoma (IDC), with 113 computer vision based mammographic features extracted from each case. To improve the baseline Model A's classification of pure vs. upstaged DCIS, we designed three different strategies (Models B, C, D) with different ways of embedding features or inputs.

RESULTS

Based on ROC analysis, the baseline Model A performed with AUC of 0.614 (95% CI, 0.496-0.733). All three new models performed better than the baseline, with domain adaptation (Model D) performing the best with an AUC of 0.697 (95% CI, 0.595-0.797).

CONCLUSION

We improved the prediction performance of DCIS upstaging by embedding two related pathology classes in different training phases.

SIGNIFICANCE

The three new strategies of embedding related class data all outperformed the baseline model, thus demonstrating not only feature similarities among these different classes, but also the potential for improving classification by using other related classes.

The international collaboration of active surveillance trials for low-risk DCIS (LORIS, LORD, COMET, LORETTA)

TPS603

Background: Retrospective data suggest breast cancer-specific survival rates with versus without surgery in patients with low-grade ductal carcinoma in situ (DCIS) are similar. Some DCIS patients have a low likelihood of progression to invasive cancer, but predicting who is at risk has not been established. Thus, treatment with a well-balanced risk / benefit ratio has not been achieved. Four active surveillance clinical trials for low risk DCIS have commenced in the United Kingdom (LORIS), Europe (LORD), United States (COMET), and Japan (LORETTA). We aim to examine the effectiveness & safety of active surveillance compared with surgical based treatment approaches for low-risk DCIS patients. Methods: Non surgical approaches are of the two types; active surveillance (AS) alone and AS + endocrine therapy (ET). In the randomized trials LORIS and LORD, the study arms are AS only, but while ET is an option in COMET, ET is mandatory in the single arm trial LORETTA. COMET and LORETTA have broader inclusion criteria as compared to LORIS and LORD. In COMET, comedo necrosis is eligible. In LORETTA, findings other than calcification on mammography (MMG) are also eligible (e.g. low echo area on breast ultrasound). Leaders of the four trials hold regular meetings to foster international DCIS trials collaboration to share information. LORIS Clinical trial information: ISRCTN27544579, LORD Clinical trial information: NCT02492607, COMET Clinical trial information: NCT02926911, LORETTA Clinical trial information: UMIN000028298 [JCOG1505]. Clinical trial information: UMIN000028298, NCT02492607, NCT02926911, ISRCTN27544579. [Table: see text]

The impact of chemotherapy sequence on survival in node-positive invasive lobular carcinoma

BACKGROUND AND OBJECTIVES

We sought to evaluate the impact of chemotherapy sequence on survival by comparing node-positive invasive lobular carcinoma (ILC) patients who received neoadjuvant (NACT) and adjuvant (ACT) chemotherapy.

METHODS

cT1-4c, cN1-3 ILC patients in the National Cancer Data Base (2004-2013) who underwent surgery and chemotherapy were divided into NACT and ACT cohorts. Kaplan-Meier curves and Cox proportional hazards modeling were used to estimate unadjusted and adjusted overall survival (OS), respectively.

RESULTS

Five thousand five hundred fifty-one (35.6%) of 15 573 ILC patients treated with chemotherapy received NACT. NACT patients had similar rates of pT3/4 disease (26.6% vs 26.2%), nodal involvement (median 3 vs 4), and number of lymph nodes examined (median 13 vs 14) but higher rates of mastectomy (81.8% vs 74.5%, P < 0.001) vs ACT patients. 3.4% of NACT patients experienced pathologic complete response (pCR). Unadjusted 10-year OS was worse for NACT vs ACT patients (65.1% vs 54.4%, log-rank P < 0.001). After adjustment for known covariates, NACT continued to be associated with worse OS (hazard ratio [HR], 1.38; 95% confidence interval [CI], 1.25-1.52).

CONCLUSIONS

In node-positive ILC, NACT yielded low rates of pCR, was not associated with lower rates of mastectomy or less extensive axillary surgery, and was associated with worse survival vs ACT, suggesting limited benefit for these patients.

Understanding the peripheral cellular immunome in patients with breast cancer

7

Background: Neoadjuvant chemotherapy (NAC) for breast cancer (BC) is being increasingly used in patients with stage I/II disease. Although previously reserved for patients with locally advanced disease, its use in patients with localized disease allows for higher rates of breast-conserving procedures and provides insight into tumor biology. A complete pathologic response (pCR) to NAC correlates with better clinical outcomes; sadly, many patients do not achieve pCR. The advent of immunotherapy has provided cancer patients with additional treatment options. To optimize immunotherapy in BC we must understand the peripheral cellular immunome (immune subsets and activation status) of patients as they undergo standard of care therapy (SOC). Methods: Our population includes patients with stages I-III BC undergoing SOC. Samples were collected pre- and post-NAC, post-surgery and at 2-month follow-up (FU). Results: Flow cytometry analysis for 11 patients was performed at each time-point to examine percentages of circulating immune cells (see Table). We grouped samples in 3 categories: human epidermal growth factor receptor 2 (HER2+) positive, HER2 negative (HER2-) and triple-negative (TN) tumors. 3 out of 11 patients had pCR (1 HER2+, 1 HER2-, 1 TN); they had highest percentage of circulating CD56+ NK cells during treatment course. Conclusions: We observed striking changes in the immunome of women with stage I-III BC undergoing NAC. Although our findings are preliminary, given our sample size, we observed distinct trends within each immune cell population in specific tumor receptor subtypes. These trends could serve to guide our therapies, allow for better patient selection and predict treatment response in patients. [Table: see text]

Intra-tumor molecular heterogeneity in breast cancer: definitions of measures and association with distant recurrence-free survival

PURPOSE

The purpose of the study was to define quantitative measures of intra-tumor heterogeneity in breast cancer based on histopathology data gathered from multiple samples on individual patients and determine their association with distant recurrence-free survival (DRFS).

METHODS

We collected data from 971 invasive breast cancers, from 1st January 2000 to 23rd March 2014, that underwent repeat tumor sampling at our institution. We defined and calculated 31 measures of intra-tumor heterogeneity including ER, PR, and HER2 immunohistochemistry (IHC), proliferation, EGFR IHC, grade, and histology. For each heterogeneity measure, Cox proportional hazards models were used to determine whether patients with heterogeneous disease had different distant recurrence-free survival (DRFS) than those with homogeneous disease.

RESULTS

The presence of heterogeneity in ER percentage staining was prognostic of reduced DRFS with a hazard ratio of 4.26 (95% CI 2.22-8.18, p < 0.00002). It remained significant after controlling for the ER status itself (p < 0.00062) and for patients that had chemotherapy (p < 0.00032). Most of the heterogeneity measures did not show any association with DRFS despite the considerable sample size.

CONCLUSIONS

Intra-tumor heterogeneity of ER receptor status may be a predictor of patient DRFS. Histopathologic data from multiple tissue samples may offer a view of tumor heterogeneity and assess recurrence risk.

The costs of breast cancer care: Patient-reported experiences and preferences for transparency

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Background: Despite the recognized side effect of financial toxicity after cancer, treatment decisions for breast cancer rarely include the costs of care. We sought to determine women’s experiences with breast cancer treatment costs, and their preferences for cost transparency at diagnosis. Methods: Women ≥18 years old with a history of breast cancer completed an 88-question electronic survey based on validated or published items. Descriptive statistics and regression analysis were used. Results: In total, 607 women with stage 0-III breast cancer participated. Median age at diagnosis was 49.6 years. Median time from diagnosis was 6.7 years (range 0.1-37.1). The majority had private (70%) insurance or Medicare (25%), and reported an annual household income ≥$74,000. 43% reported considering costs in treatment decisions. Median reported out-of-pocket (OOP) costs were $3,500; 25% reported OOP costs ≥$8,000, 10% reported OOP costs ≥$18,000 and 5% reported OOP costs ≥$30,000. 15.5% reported significant to catastrophic financial burden. Bilateral mastectomy +/- reconstruction vs lumpectomy (OR 1.9, p 0.03), greater stage at diagnosis (stage 3 vs 0, OR 3.9, p < 0.01), and discussion of costs during the clinical encounter (OR 2.3, p < 0.01) were associated with a higher risk of financial harm. Women who reported discussing costs were more likely to be stage 2 or 3 (56% vs 40%, p = 0.02), less likely to be depressed (24% vs 30%, p = 0.03), and had less insurance coverage (trend p = 0.02) compared to those who did not. Older age (OR 0.95, p < 0.01), increasing household income (overall p < 0.001), better insurance coverage (OR 0.5, p < 0.001), and longer time since diagnosis (OR 0.65, p < 0.001) was associated with a decreased risk of financial harm. 78% of participants never discussed costs with their cancer team. 79% preferred cost transparency prior to embarking on care, and 40% preferred that doctors consider costs when making recommendations. Conclusions: Many women with breast cancer reported significant financial burden related to their care, and the vast majority preferred knowing costs at diagnosis. Cost transparency may improve the quality of preference-sensitive treatment decisions and reduce the risk of financial harm.

Seeking a no-regrets decision: Women's rationale for choosing contralateral prophylactic mastectomy (CPM)

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Background: More women with early-stage unilateral breast cancer and low genetic risk are opting for CPM, despite their low risk of developing cancer in their healthy breast and evidence to demonstrate that CPM improves neither survival nor quality of life, while increasing the risk of surgical complications. Little is known about the factors that motivate this irreversible decision. Methods: We conducted comprehensive qualitative interviews with 42 women at low risk for contralateral breast cancer (CBC) who had CPM in the last 10 years. We recorded and transcribed the interviews and analyzed them using a grounded theory approach. Results: Contrary to hypotheses that newly diagnosed women overestimate their CBC risk, study patients knew of the low risk of cancer in their healthy breast, but still chose CPM. Statistics were unpersuasive; given healthy lifestyles and lack of risk factors, they felt unlucky to get breast cancer and feared they would be unlucky again. They believed CPM would give them more peace of mind and the fewest regrets should cancer return. Avoiding mammograms was important, given the potential for callbacks, biopsies, and more bad news. Avoiding radiation and wanting matching breasts were cited less often. Most were mainly focused on reducing their cancer risk and could not recall having critical information about CPM’s potential harms. A few knew of likely harms but misjudged their impact. When told of CPM’s higher risk of complications, most dismissed this as a disclaimer, believing they would get through surgery well. Despite experiencing negative effects of CPM, 38 of 42 stated they would make the same decision again. Conclusions: When choosing CPM, most women felt confident in making their decision, although many had incomplete knowledge of potential long-term impacts. Nevertheless the majority of women who chose CPM did not regret their decision, suggesting that women who elect CPM are selecting a treatment option that is consistent with their long-term personal values and preferences. While important to ensure women know potential long-term harms, our findings suggest they may not necessarily be dissuaded from CPM by more data, though they may be better prepared for it’s aftermath.

Trends and variations in postmastectomy radiation therapy for breast cancer in patients with 1 to 3 positive lymph nodes: A National Cancer Data Base analysis

BACKGROUND

High-level evidence is lacking to guide treatment decisions about postmastectomy radiation therapy (PMRT) in patients who have breast cancer with 1 to 3 positive lymph nodes who receive contemporary systemic therapies, leading to potential variations in PMRT delivery. The objective of this study was to examine nationwide trends in PMRT use in this group.

METHODS

The National Cancer Data Base (NCDB) was used to identify 93,372 women who had T1-T2N1 breast cancer diagnosed between 2003 and 2012. Patients who received neoadjuvant chemotherapy or radiation therapy (RT) and those who had bilateral breast cancers were excluded. Time trends were evaluated using the Cochrane-Armitage test and correlated the receipt of PMRT with various patient demographic, facility, clinicopathologic, and treatment variables using multivariable logistic regression. A second analysis was performed for patients who were diagnosed during 2010 and included radiation oncologist density as an additional covariate. P values < .0001 were considered statistically significant.

RESULTS

Overall, 22.5% of the study population received PMRT, representing an increase from 19.1% in 2003 to 30.3% in 2012. Factors associated with greater PMRT use included younger age, lower Charlson-Deyo comorbidity scores, shorter distance to the treating facility, treatment at a comprehensive cancer program, facility location in the New England Census division, and higher density of radiation oncologists. Increased PMRT use was associated with later year of diagnosis, receipt of chemotherapy, receipt of hormone therapy, higher grade disease, larger tumor size, greater numbers of positive lymph nodes, positive margins, and absence of immediate breast reconstruction (all P < .0001).

CONCLUSIONS

The receipt of PMRT by patients with breast cancer who have 1 to 3 positive lymph nodes has increased over time, with wide variability in practice patterns in the United States. Cancer 2018;124:482-90. © 2017 American Cancer Society.

Serum phosphatidylcholine is lower among breast cancer patients on systemic chemotherapy

e12571

Background: Chemotherapy-induced cognitive impairment, also known as 'chemobrain', is widely recognized as a frequent adverse effect of chemotherapy, occurs in 10-40% of all cancer patients. Those cancer survivors suffer from poor concentration, memory, abstract reasoning, and motor dysfunction. The etiology is unclear. In our study, we analyzed the metabolite panels in breast cancer patients with vs. without chemotherapy trying to identify metabolic mediators of neurologic injury. Methods: We obtained plasma sample from 18 breast cancer patients, 9 received chemotherapy prior to blood drawn; while the other 9 had no systemic therapy. The plasma samples were sent for mass spectroscopy. Each metabolites level was normalized, and the two groups were compared in each metabolite by t-test with statistical significance corrected for multiple comparisons using the Holm-Sidak method. Results: We identified 57 amines and their metabolites; 106 carbohydrate related metabolites, and 228 lipid molecules. While amino acid, and carbohydrate did not show significant difference, phosphatidylcholine level in the chemotherapy treated group demonstrated lower level in the patients received chemotherapy. Among 59 phosphatidylcholine identified, 6 variants were significantly lower in the chemo group compare with non chemo group. Additionally the sum of all phosphatidylcholine variants was diminished in the chemotherapy treated patients compared with untreated controls. No other differences in plasma lipid levels were identified. Conclusions: Phosphatidylcholine is a major component of cell membranes and lipid rafts which are critical elements in nerve conduction. It also plays a role as the precursor to the neurotransmitter acetylcholine. The finding that phosphatidylcholine is significantly different between chemotherapy treated vs. the no chemotherapy group raises the possibility that lipid metabolism contributes to chemotherapy-induced cognitive impairment and further experiments are planned to explore this hypothesis.

Role of axillary node dissection after mastectomy with positive sentinel nodes

554

Background: The ACOSOG Z11 trial demonstrated that sentinel lymph node biopsy (SLNB) alone was safe for women with early stage node positive cancer undergoing breast conservation therapy with radiation. Little data exists regarding management of this population undergoing mastectomy. The purpose of our study is to determine the benefit of axillary lymph node dissection (ALND) or SLNB with adjuvant radiation in patients with 1-3 positive SLN after mastectomy. Methods: Using data from the National Cancer Database (2004-2014), we performed a retrospective review of patients who underwent mastectomy and were clinically node negative at presentation, but were found to have 1-3 positive nodes on pathology. Patients were categorized as undergoing SLNB alone (1-5 nodes examined) or ALND (≥8 nodes examined). Patients who received SLNB without ALND were further categorized by receipt of radiation treatment (RT). Patients with either neoadjuvant chemotherapy or stage IV disease were excluded. Results: Of 42,371 patients, 10.0% had SLNB+RT, 22.4% had SLNB alone, and 67.5% had ALND. Median age of the cohort was 58 years and median tumor size 2.3 cm. Median follow up was 4.1 years. After adjustment for covariates including age at diagnosis, tumor size, chemotherapy, endocrine therapy and receptor status, SLNB+RT had comparable overall survival to ALND (HR = 1.06, p = 0.52), but SLNB alone was found to be associated with a 25% increase in hazard of death compared to ALND (HR = 1.25, 95% CI 1.11-1.41, p < 0.001). Conclusions: In clinically node negative patients with 1-3 positive sentinel nodes treated with mastectomy, SLNB alone was associated with a significantly increased risk of all-cause mortality compared to ALND or SLNB+RT. These results suggests that ALND may be avoided in these patients in the setting of adjuvant radiation, possibly avoiding the morbidity associated with axillary lymphadenectomy.

Temporal associations between prognostic indicators and overall survival after breast cancer

e18144

Background: Breast oncologists have little guidance on predicting long term outcomes after interval survival. We aim to evaluate the association of overall survival (OS) with select factors at multiple time points. Methods: Women ages 18-80 with non-metastatic invasive breast cancer were identified from the NCDB (2004─2014). Using multivariate survival analysis, we estimated the association of OS with tumor and treatment factors for those with follow up surviving at least 2, 5, and 10y post-diagnosis. Results: 685598 women (median age 59) were identified; 573757 were alive with follow up at 2y, 254303 at 5y, and 18640 at 10y. The majority had early stage, hormone receptor (HR) +, invasive ductal carcinoma. 57% underwent lumpectomy; 49% received chemotherapy; 89% of lumpectomies received radiation (RT); and 83% of HR+ tumors received endocrine therapy (ET). Of those alive at 2y, improved OS was associated with ER+, PR+, chemotherapy, RT, and ET. Reduced OS was associated with higher cT/cN stage, grade, and mastectomy. Of those alive at 5y, improved OS was associated with chemotherapy, RT, and ET. Reduced OS was associated with higher cT/cN stage, grade, and mastectomy. Of those alive at 10y, reduced OS was associated with higher cT stage and grade. Conclusions: Tumor and treatment factors are associated with OS, but the association of some factors may change for women surviving at least 5y or 10y. These findings may contribute to more tailored prognostication for patients based on interval survival. [Table: see text]

The epidemiology of metaplastic breast cancer: A review of 2,500 cases from the national cancer database

1570

Background: Metaplastic breast cancer (MBC) is a rare, aggressive, sarcomatoid breast cancer that was first described in 1973 but only became recognized as a histologically distinct entity in 2000. Given the paucity of data on the epidemiology of MBC, we performed a population-based analysis to delineate sociodemographic and clinicopathological characteristics associated with increased likelihood of MBC diagnosis. Methods: Adult female breast cancer patients with stage I-III MBC and non-MBC histology diagnosed between 2010 and 2013 were identified in the National Cancer Database (NCDB). Multivariate logistic regression was used to identify factors associated with diagnosis of MBC, and Cox proportional hazards modeling was used to estimate the effect of MBC on overall survival. Results: 2,451 MBC and 568,057 non-MBC patients were identified. After adjusting for receptor status (ER, PR, HER2), age, stage, grade, and treatment variables, MBC patients had worse survival than non-MBC patients (HR 1.45, p < 0.001). Compared to non-MBC patients, a higher proportion of MBC patients were non-Hispanic black (16.7% vs 10.5%), had an annual income < $35k (29.0% vs 25.5%), had lower high school completion rates (36.7% vs 33.9%), were treated at academic centers (35.5% vs 30.8%), and had government-sponsored insurance (48.8% vs 43.7%, all p < 0.01). MBC diagnosis was more likely in patients with triple-negative breast cancer (OR 20.71), higher clinical T stage (cT4 vs cT1: OR 6.18), and lower clinical N stage (cN1 vs cN0: OR 0.38, all p < 0.001). MBC patients were also more likely to be diagnosed based on pathology from their first operation rather than preoperatively (OR 1.41, p < 0.001). Conclusions: Black women and women of low socioeconomic status were at increased risk for diagnosis with MBC. Though MBC was more likely to be treated at academic centers, MBC was less likely to be diagnosed prior to surgical intervention. Many of the sociodemographic factors associated with MBC have also been associated with triple-negative breast cancer. Additional research is needed to determine the contribution of sociodemographic factors to the epidemiology of MBC independent of receptor status.

Impact of insurance status on treatment for stage 0-IV breast cancer

6532

Background: Health insurance can influence utilization of cancer care. We sought to determine whether insurance status impacts treatment patterns and survival in women with stage 0-IV breast cancer. Methods: Women ages 18-69 years old, diagnosed with unilateral stage 0-IV breast cancer between 2004 and 2014 were selected from the National Cancer Data Base. Insurance status was categorized as Private, Medicare (65+ yo), Medicare (18-64 yo), Medicaid, or Uninsured. After adjustment for known covariates, generalized and binary logistic regression were used to estimate the association of insurance type with receipt of treatment. A multivariate Cox proportional hazards model was used to estimate the association of insurance status with overall survival. Results: A total of 610,450 women met inclusion criteria. Median age was 56 (48-63). Insurance status included: 72.1% Privately insured, 13.9% Medicare 65+, 4.8% Medicare 18-64, 7.1% Medicaid, and 2.1% Uninsured. Women with private insurance were more likely to present with stage 1 breast cancer, and less likely to present with stage 4 disease when compared to Medicaid or Uninsured patients (stage 1: 63.4%, 49.4%, 48.2%, p < 0.01; stage IV: 0.8%, 1.8%, 2.1%, p < 0.01). Risk of death was higher in uninsured or Medicaid patients when compared to those with private insurance (HR 1.52, 95% CI 1.41-1.64; HR 1.6, 95% CI 1.52-1.68). Receipt of chemotherapy and radiation did not differ between Medicaid, Uninsured, or Privately insured patients, but women without private insurance were more likely to receive neoadjuvant chemotherapy (OR 1.14, 95% CI 1.09-1.19; OR 1.16, 95% CI 1.07-1.25, respectively, p < 0.01). Uninsured women were more likely to undergo mastectomy without reconstruction (OR 1.57, 95% CI 1.49-1.65), and less likely to undergo unilateral or bilateral mastectomy with reconstruction than lumpectomy and radiation (OR 0.57, 95% CI 0.53-0.61; OR 0.35, 95% CI 0.32-0.39). Conclusions: Stage at diagnosis and risk of death were higher in Medicaid and uninsured breast cancer patients when compared to those with private insurance. Insurance status did not predict differences in receipt of surgery, chemotherapy, or radiation but did affect oncologic outcomes.

A population-based analysis of treatment and outcomes in 2,500 metaplastic breast cancer patients

532

Background: Metaplastic breast cancer (MBC) is a rare, aggressive variant that is often triple negative (TN). Current guidelines recommend use of standard receptor-based treatment for MBC despite evidence of chemoresistance. We sought to compare treatment patterns and outcomes of MBC and non-MBC. Methods: Women age > 18 with stage I-III MBC and non-MBC histology diagnosed from 2010-2013 were identified in the National Cancer Database. Kaplan Meier and multivariate Cox proportional hazards models were used to estimate MBC association with overall survival (OS). Subgroup analyses were conducted for (1) MBC patients only and (2) TN MBC and TN non-MBC patients. Results: 2451 MBC and 568,057 non-MBC patients were included. 70.3% of MBC were TN vs 11.3% of non-MBC (p < 0.001). 19.2% of MBC were luminal (i.e., ER+ and/or PR+, and HER2-). MBC presented with higher clinical T stage (cT4: 5.4% vs 1.8%) and grade (grade 3: 72.1% vs 29.7%) but was less frequently node-positive (19.1% vs 29.7%, all p < 0.001). A higher proportion of MBC patients were treated with mastectomy (59.0% vs 44.9%), axillary dissection (ALND, 35.2% vs 32.2%), and chemotherapy (74.1% vs 43.1%, all p≤0.001). 5-year OS was reduced among MBC vs non-MBC patients for both the entire cohort (72.7% vs 87.5%) and the TN-only analysis (71.1% vs 77.8%, both log-rank p < 0.001). Among MBC cases, TN subtype was not associated with worse OS than the luminal subtype (HR 1.16, p = 0.28). Chemotherapy (HR 0.69, p = 0.004) and/or radiotherapy (HR 0.52, p < 0.001) improved OS in MBC, and the proportional benefit of chemotherapy did not vary with pathological T or N stage (interaction p > 0.05 for both). Among TN patients, a higher proportion of TN MBC patients underwent mastectomy (58.4% vs 49.5%, p < 0.001), but in contrast to the full cohort, a lower proportion of TN MBC patients received chemotherapy (76.6% vs. 78.7%, p = 0.008) and ALND (35.2% vs. 38.2%, p = 0.01) vs TN non-MBC patients. Conclusions: MBC had worse OS vs non-MBC, and unlike other histologies, outcome was not driven by receptor status. Multimodal therapy improved outcomes. Further investigation into MBC tumor biology and the development of MBC-specific guidelines could potentially improve treatment standardization and outcomes.

Abstract B44: Immune pathway dysregulations in inflammatory breast cancer health disparity

Background: Inflammatory breast cancer (IBC) is a distinct, aggressive and the most lethal form of breast cancer. Furthermore, data from population-based registries, when stratified by race and compared to other locally advanced breast cancers, suggest that IBC has a disproportionately high incidence, prevalence & shorter median survival time in African Americans (AA) compared to Caucasian American (CA) patients. IBC health disparities that are independent of external factors like differences in income, screening rates, and access to health care suggest a biological component to poor outcomes. IBC pathobiology is also unique wherein instead of a solid tumor, tightly packed tumor cell clusters/emboli are formed with a propensity for lymphatic dissemination. The underlying mechanisms for this extremely aggressive breast cancer phenotype are largely unknown and, therefore, present a major impediment to identifying the molecular underpinnings for health disparities in IBC patients.

Methods and Results: In order to understand how IBC cells evade cell death signals in the host microenvironment, we conducted comparative analysis of the largest collection of untreated primary tumor samples of IBC (N=137), along with stage- and subtype-matched non-IBC (N=252) and normal breast tissue. Results reveal that pretreatment tumor tissue samples from IBC patients have a heightened expression of adaptive stress response genes comprised of high levels of the nuclear transcription factor, NFkappaB, and its target genes in the anti-apoptotic and immune/inflammatory pathways that correlate with cell survival. In addition, guided by analysis based on presence of tumor infiltrating leukocytes in IBC (N=69) and non-IBC (N=62) patient samples, we have identified a set of pathways and genes that have the ability to distinguish the immune responses in IBC and non-IBC patients in a subtype independent manner. In particular, interferon alpha/beta and NFκB signaling pathways were differentially regulated in IBC vs. non-IBC. Gene expression driven analysis of enrichment of leukocyte subsets reveal specific differences in plasma cells and effector memory CD8 cells in IBC bulk tumor samples. Preliminary data analysis of gene expression data sets from laser microdissected epithelium and stromal compartments of AA and CA breast cancer patients also show enrichment of plasma cells, effector memory CD4+, and M1 macrophages. Studies are ongoing to characterize these immune profiles that are unique and distinguishable in IBC patients and further identify race-related differences. Most importantly, we discovered that the constitutive NFκB hyperactivation observed in IBC tumor cells is driven by stress-mediated translational upregulation of the most potent anti-apoptotic protein, XIAP. Interestingly, XIAP:NFκB overexpressing cells are highly resistant to immunotherapy mediated cell death. These data strongly suggest that in IBC, host immune phenotype promotes outgrowth of cell death resistant population and specific tumor cell pro-survival signaling mechanisms that enhances invasion and lymphatic dissemination. We have developed novel in vitro IBC tumor emboli culture model and a transgenic mouse bearing red fluorescent lymphatic vasculature that allow recapitulating host factors to define tumor cell signaling mechanisms on immune effector function and the resultant invasive phenotype.

Conclusions: As the incidence is rising and targets for therapy are scant, IBC has the potential to become a major public health disparity concern. This study reveals that the immune factors in the host microenvironment may interact with underlying IBC genetics to promote the aggressive nature of the tumor, and more specifically, these factors may be one of the sources of biologic variation between patients of different ethnicities leading to IBC disparity outcomes. Supported in part by Duke IBC Consortium, DCI NIH CAO14236 development funds (GRD), DoD W81XWH-13-1-0047 (GRD).

Citation Format: Gayathri R. Devi, Eun-Sil Shelley Hwang, John Stewart, Michael A. Morse, Steven Van Laere. Immune pathway dysregulations in inflammatory breast cancer health disparity. [abstract]. In: Proceedings of the Ninth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2016 Sep 25-28; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2017;26(2 Suppl):Abstract nr B44.

Prognostic impact of the 21-gene recurrence score in patients presenting with stage IV breast cancer

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Background: The 21-gene Recurrence Score (OncotypeDX Breast Cancer Assay) predicts outcome and benefit from chemotherapy (CT) in early stage ER+ BC treated with adjuvant endocrine therapy. We evaluated the association between Recurrence Score (RS), time to progression (TTP), and overall survival (OS) in patients with stage IV BC enrolled in TBCRC 013. Methods: TBCRC 013 is a registry study evaluating surgery of the primary tumor in pts presenting with Stage IV BC. From 7/09 - 4/12, 128 evaluable pts were enrolled in two cohorts (A: metastases (mets) with intact primary tumor (n=112); B: mets within 3 months of primary surgery (n=16)). This study includes 110 pts with pre-treatment primary tumor samples available for analysis. Clinical variables, TTP and OS were correlated with RS using long-rank, Kaplan-Meier and Cox regression. Results: Median pt age was 52yrs (21-79) and median tumor size 3.1cm (0.7-15). 82 (80%) were ER+, 83 (81%) Her2(-) and 51 (46%) had bone-only mets. Cohorts A and B did not differ. At a median follow-up of 26 mos (1-47), median TTP is 19 mos (95%CI16-25) and surgery is not associated with OS. 102 samples qualified for RS. 23 (23%) had low RS<18, 29 (28%) intermediate RS, 18-30; and 50 (49%) high RS≥31. Age, tumor size or site of 1stmets was not associated with RS. Risk groups were prognostic for TTP in ER+ pts and for 2 yr OS in ER+Her2- pts (Table). In Cox models continuous RS was also prognostic for TTP in ER+ pts (HR 3.5; for 50 point difference (PD) 95%CI 1.5-8.1, p=0.003) and for OS in ER+Her2- pts (HR 21.4, for 50 PD 95%CI 2.2-204.4, p=0.008). In MVA, adjusting for clinical variables, RS remained prognostic for TTP in ER+ pts (p=0.01). Further analysis of surgery in this trial is ongoing. Conclusions: The 21-gene RS is independently prognostic for TTP in ER+ Stage IV BC. RS is also prognostic for OS in ER+Her2- BC, suggesting that a high RS may be a surrogate for endocrine resistance and could be used to select pts with ER+ Stage IV BC for CT. A randomized trial to address this hypothesis is warranted. Clinical trial information: NCT00941759. [Table: see text]

Abstract P5-14-02: Immediate Breast Reconstruction: The Effect of Radiation

Background:

Prior history of breast irradiation or anticipated need for postmastectomy radiation have been considered relative contraindications for immediate breast reconstruction. We evaluated the surgical outcomes between three groups of patients: patients without radiation exposure, those with radiation prior to immediate reconstruction, and those with radiation following immediate reconstruction to determine the differences in risk of post-surgical complications among groups. Methods:

All patients undergoing mastectomy and immediate reconstruction with either a tissue expander or implant between January 1, 2005 and June 30, 2009 were entered into an IRB-approved prospective database. Routine institutional protocol consisted of immediate reconstruction with tissue expander, expansion during the1-2 months following surgery, radiation if indicated, followed by implant exchange at 3-6 months after completion of radiation. All complications were collected and recorded within a week of the event, and all patients had a minimum follow-up period of 6 months after implant exchange to allow for sufficient monitoring of complications. Major complications included infection requiring IV antibiotics, unplanned return to surgery, and tissue expander/implant loss. Results:

A total of 446 mastectomies were identified. Of these, 341 had no radiation history, 33 had prior ipsilateral breast radiation, and 72 had post-mastectomy radiation. Overall, there were 160 major complications (36%), including 50 (11%) expander/implant losses. Patient age, BMI, diabetes, and history of tobacco use were not associated with increased risk of major complications in this cohort. However, both prior and postoperative radiation was associated with higher risk of both major complications and implant loss.

Conclusion:

Immediate reconstruction with implant or tissue expander is associated with a 36% risk of major postoperative complications, with the greatest number seen in those patients with history of previous chest wall irradiation. However, most implants were salvaged even in the setting of complications, and the overall implant loss rate was only 8% in unirradiated patients and 22% in those patients with postoperative RT. Although radiation history is not a contraindication to immediate breast reconstruction, patients undergoing this procedure must be well informed of their substantial risk of postoperative complications.