Endothelial dysfunction in breast cancer survivors on aromatase inhibitors: changes over time

BACKGROUND

Breast cancer is estimated to comprise about 290,560 new cases in 2022. Aromatase inhibitors (AIs) are recommended as adjuvant treatment for estrogen-receptor positive (ER+) breast carcinoma in postmenopausal women, which includes approximately two-thirds of all women with breast cancer. AIs inhibit the peripheral conversion of androgens to estrogen by deactivation of the aromatase enzyme, leading to a reduction in serum estrogen level in postmenopausal women with ER+ breast carcinoma. Estrogen is known for its cardiovascular (CV) protective properties through a variety of mechanisms including vasodilation of blood vessels and inhibition of vascular injury resulting in the prevention of atherosclerosis. In clinical trials and prospective cohorts, the long-term use of AIs can increase the risk for hypertension and hyperlipidemia. Studies demonstrate mixed results as to the impact of AIs on actual CV events and overall survival.

METHODS

A single arm longitudinal study of 14 postmenopausal women with ER+ breast cancer prescribed adjuvant AIs at the University of Minnesota (UMN). Subjects with a history of known tobacco use, hypertension, hyperlipidemia, and diabetes were excluded to eliminate potential confounding factors. Participants underwent routine labs, blood pressure assessments, and vascular testing at baseline (prior to starting AIs) and at six months. Vascular assessment was performed using the EndoPAT 2000 and HDI/PulseWave CR-2000 Cardiovascular Profiling System and pulse contour analysis on two occasions as previously described. Vascular measurements were conducted by one trained vascular technician. Assessments were performed in triplicate, and the mean indices were used for analyses. All subjects were on an AI at the follow-up visit. The protocol was approved by the UMN Institutional Review Board and all participants were provided written informed consent. Baseline and follow-up characteristics were compared using Wilcoxon signed-rank tests. Analyses were performed using R version 3.6.1 (R Foundation for Statistical Computing, Vienna, Austria).

RESULTS

After six months of AI treatment, EndoPAT® ratio declined to a median 1.12 (Q1: 0.85, Q3: 1.86; p = 0.045; Figure 1) and median estradiol levels decreased to 2 pg/mL (Q1: 2, Q3: 3; p=0.052). There was no evidence of association between change in EndoPAT® and change in estradiol level (p = 0.91). There were no statistically significant changes in small or large arterial elasticity.

CONCLUSIONS

We hypothesize that long-term use of AI can lead to persistent endothelial dysfunction, and further investigation is necessary. In our study, patients were on AI for approximately 5-10 years. As a result, we do not have data on whether these changes, such as EndoPAT® ratio and the elasticity of small and large arterial, are reversible with discontinuation of AI. These findings set the stage for a larger study to more conclusively determine the association between AI exposure and cardiovascular outcomes. Further studies should evaluate for multivariate associations withmodifiable risk factors for CV disease.

Impact of body mass index on pathological response after neoadjuvant chemotherapy: results from the I-SPY 2 trial

PURPOSE

Increased body mass index (BMI) has been associated with poor outcomes in women with breast cancer. We evaluated the association between BMI and pathological complete response (pCR) in the I-SPY 2 trial.

METHODS

978 patients enrolled in the I-SPY 2 trial 3/2010-11/2016 and had a recorded baseline BMI prior to treatment were included in the analysis. Tumor subtypes were defined by hormone receptor and HER2 status. Pretreatment BMI was categorized as obese (BMI ≥ 30 kg/m2), overweight (25 ≤ BMI < 30 kg/m2), and normal/underweight (< 25 kg/m2). pCR was defined as elimination of detectable invasive cancer in the breast and lymph nodes (ypT0/Tis and ypN0) at the time of surgery. Logistic regression analysis was used to determine associations between BMI and pCR. Event-free survival (EFS) and overall survival (OS) between different BMI categories were examined using Cox proportional hazards regression.

RESULTS

The median age in the study population was 49 years. pCR rates were 32.8% in normal/underweight, 31.4% in overweight, and 32.5% in obese patients. In univariable analysis, there was no significant difference in pCR with BMI. In multivariable analysis adjusted for race/ethnicity, age, menopausal status, breast cancer subtype, and clinical stage, there was no significant difference in pCR after neoadjuvant chemotherapy for obese compared with normal/underweight patients (OR = 1.1, 95% CI 0.68-1.63, P = 0.83), and for overweight compared with normal/underweight (OR = 1, 95% CI 0.64-1.47, P = 0.88). We tested for potential interaction between BMI and breast cancer subtype; however, the interaction was not significant in the multivariable model (P = 0.09). Multivariate Cox regression showed there was no difference in EFS (P = 0.81) or OS (P = 0.52) between obese, overweight, and normal/underweight breast cancer patients with a median follow-up time of 3.8 years.

CONCLUSION

We found no difference in pCR rates by BMI with actual body weight-based neoadjuvant chemotherapy in this biologically high-risk breast cancer population in the I-SPY2 trial.

Impact of Body Mass Index on Pathological Response after Neoadjuvant Chemotherapy: Results from the I-SPY 2 trial

Purpose

Increased body mass index (BMI) has been associated with poor outcomes in women with breast cancer. We evaluated the association between BMI and pathological complete response (pCR) in the I-SPY 2 trial.

Methods

978 patientsenrolled in the I-SPY 2 trial 3/2010-11/2016 and had a recorded baseline BMI prior to treatment were included in the analysis. Tumor subtypes were defined by hormone receptor and HER2 status. Pretreatment BMI was categorized as obese (BMI≥30 kg/m2), overweight (25≤BMI < 30 kg/m2), and normal/underweight (< 25 kg/m2). pCR was defined as elimination of detectable invasive cancer in the breast and lymph nodes (ypT0/Tis and ypN0) at the time of surgery. Logistic regression analysis was used to determine associations between BMI and pCR. Event-free survival (EFS) and overall survival (OS) between different BMI categories were examined using Cox proportional hazards regression.

Results

The median age in the study population was 49 years. pCR rates were 32.8% in normal/underweight, 31.4% in overweight, and 32.5% in obese patients. In univariable analysis, there was no significant difference in pCR with BMI. In multivariable analysis adjusted for race/ethnicity, age, menopausal status, breast cancer subtype, and clinical stage, there was no significant difference in pCR after neoadjuvant chemotherapy for obese compared with normal/underweight patients (OR = 1.1, 95% CI: 0.68-1.63, p = 0.83), and for overweight compared with normal/underweight (OR = 1, 95% CI: 0.64-1.47, p = 0.88). We tested for potential interaction between BMI and breast cancer subtype; however, the interaction was not significant in the multivariable model (p = 0.09). Multivariate Cox regression showed there was no difference in EFS (p = 0.81) or OS (p = 0.52) between obese, overweight, and normal/underweight breast cancer patients with a median follow-up time of 3.8 years.

Conclusions

We found no difference in pCR rates by BMI with actual body weight based neoadjuvant chemotherapy in this biologically high-risk breast cancer population in the I-SPY2 trial.

Endothelial Dysfunction in Breast Cancer Survivors on Aromatase Inhibitors: Changes over Time

Background

Aromatase inhibitors (AIs) are recommended as adjuvant treatment for estrogen-receptor positive breast carcinoma in postmenopausal women. Studies demonstrate mixed results as to the impact of AIs on cardiovascular (CV) events and overall survival. With the increasing number of pre- and postmenopausal women on AIs for five to ten years, understanding the long-term impact of AIs on blood vessels and CV risk in cancer survivors is vital.

Methods

A single arm longitudinal study of 14 postmenopausal women with ER+ breast cancer prescribed adjuvant AIs at the University of Minnesota. Subjects with a history of tobacco use, hypertension, or hyperlipidemia were excluded. Participants underwent routine labs, blood pressure assessments, and vascular testing at baseline (prior to starting AIs) and at six months. Vascular assessment was performed using the EndoPAT 2000 and HDI/PulseWave CR-2000 Cardiovascular Pro ling System and pulse contour analysis on two occasions as previously described. Vascular measurements were conducted by one trained vascular technician. Assessments were performed in triplicate, and the mean indices were used for analyses. All subjects were on an AI at the follow-up visit. The protocol was approved by the UMN Institutional Review Board and all participants were provided written informed consent. Baseline and follow-up characteristics were compared using Wilcoxon signed-rank tests. Analyses were performed using R version 3.6.1 (R Foundation for Statistical Computing, Vienna, Austria).

Results

After six months of AI treatment, EndoPAT® ratio declined to a median 1.12 (Q1: 0.85, Q3: 1.86; p=0.045) and median estradiol levels decreased to 2 pg/mL (Q1: 2, Q3: 3; p=0.052). There was no evidence of association between change in EndoPAT® and change in estradiol level (p=0.91). There were no statistically significant changes in small or large arterial elasticity.

Conclusion

Endovascular dysfunction is an early sign for atherosclerosis and vascular impairment. This study suggests that postmenopausal breast cancer survivors on aromatase inhibitor therapy develop endothelial dysfunction as early as six months which is a predictor of adverse CV disease. We hypothesize that long-term use of AIs can lead to persistent endothelial dysfunction. It is unclear if these changes are reversible once AI use is discontinued and further investigation is necessary.

Outcomes and clinicopathologic characteristics associated with disseminated tumor cells in bone marrow after neoadjuvant chemotherapy in high-risk early stage breast cancer: the I-SPY SURMOUNT study

PURPOSE

Disseminated tumor cells (DTCs) expressing epithelial markers in the bone marrow are associated with recurrence and death, but little is known about risk factors predicting their occurrence. We detected EPCAM+/CD45- cells in bone marrow from early stage breast cancer patients after neoadjuvant chemotherapy (NAC) in the I-SPY 2 Trial and examined clinicopathologic factors and outcomes.

METHODS

Patients who signed consent for SURMOUNT, a sub-study of the I-SPY 2 Trial (NCT01042379), had bone marrow collected after NAC at the time of surgery. EPCAM+CD45- cells in 4 mLs of bone marrow aspirate were enumerated using immunomagnetic enrichment/flow cytometry (IE/FC). Patients with > 4.16 EPCAM+CD45- cells per mL of bone marrow were classified as DTC-positive. Tumor response was assessed using the residual cancer burden (RCB), a standardized approach to quantitate the extent of residual invasive cancer present in the breast and the axillary lymph nodes after NAC. Association of DTC-positivity with clinicopathologic variables and survival was examined.

RESULTS

A total of 73 patients were enrolled, 51 of whom had successful EPCAM+CD45- cell enumeration. Twenty-four of 51 (47.1%) were DTC-positive. The DTC-positivity rate was similar across receptor subtypes, but DTC-positive patients were significantly younger (p = 0.0239) and had larger pretreatment tumors compared to DTC-negative patients (p = 0.0319). Twenty of 51 (39.2%) achieved a pathologic complete response (pCR). While DTC-positivity was not associated with achieving pCR, it was significantly associated with higher RCB class (RCB-II/III, 62.5% vs. RCB-0/I; 33.3%; Chi-squared p = 0.0373). No significant correlation was observed between DTC-positivity and distant recurrence-free survival (p = 0.38, median follow-up = 3.2 years).

CONCLUSION

DTC-positivity at surgery after NAC was higher in younger patients, those with larger tumors, and those with residual disease at surgery.

Safety and efficacy of HSP90 inhibitor ganetespib for neoadjuvant treatment of stage II/III breast cancer

HSP90 inhibitors destabilize oncoproteins associated with cell cycle, angiogenesis, RAS-MAPK activity, histone modification, kinases and growth factors. We evaluated the HSP90-inhibitor ganetespib in combination with standard chemotherapy in patients with high-risk early-stage breast cancer. I-SPY2 is a multicenter, phase II adaptively randomized neoadjuvant (NAC) clinical trial enrolling patients with stage II-III breast cancer with tumors 2.5 cm or larger on the basis of hormone receptors (HR), HER2 and Mammaprint status. Multiple novel investigational agents plus standard chemotherapy are evaluated in parallel for the primary endpoint of pathologic complete response (pCR). Patients with HER2-negative breast cancer were eligible for randomization to ganetespib from October 2014 to October 2015. Of 233 women included in the final analysis, 140 were randomized to the standard NAC control; 93 were randomized to receive 150 mg/m2 ganetespib every 3 weeks with weekly paclitaxel over 12 weeks, followed by AC. Arms were balanced for hormone receptor status (51-52% HR-positive). Ganetespib did not graduate in any of the biomarker signatures studied before reaching maximum enrollment. Final estimated pCR rates were 26% vs. 18% HER2-negative, 38% vs. 22% HR-negative/HER2-negative, and 15% vs. 14% HR-positive/HER2-negative for ganetespib vs control, respectively. The predicted probability of success in phase 3 testing was 47% HER2-negative, 72% HR-negative/HER2-negative, and 19% HR-positive/HER2-negative. Ganetespib added to standard therapy is unlikely to yield substantially higher pCR rates in HER2-negative breast cancer compared to standard NAC, and neither HSP90 pathway nor replicative stress expression markers predicted response. HSP90 inhibitors remain of limited clinical interest in breast cancer, potentially in other clinical settings such as HER2-positive disease or in combination with anti-PD1 neoadjuvant chemotherapy in triple negative breast cancer.Trial registration: www.clinicaltrials.gov/ct2/show/NCT01042379.

729 INCORPORATING PATIENTS’ VIEWS IN THE DESIGN OF AN EDUCATIONAL LEAFLET FOR FRAIL, OLDER PATIENTS WITH KIDNEY DISEASE

Introduction

There are an increasing number of older people live with advanced kidney disease. These individuals tend to have a higher number of co-morbidities, including frailty. This group experience multiple challenges in understanding and managing their co-existing conditions. This quality improvement project aimed to incorporate patient and carers views and experiences to improve their understanding and support self-management.

Method

Semi-structured interviews were conducted with older patients with advanced kidney disease and their carers. Interviews explored their views on ageing and frailty, how it affects them, coping strategies, resource awareness and opinions on structure and content for an educational leaflet for older people with kidney disease. The interviews were transcribed verbatim then coded into themes to inform key topics for the leaflet. These were used to generate reader-friendly questions and answers. The leaflet was reviewed and approved by the Clinical Committee and Patient Information Board in Kidney Care UK.

Results

10 individuals (8 patients and 2 carers) were interviewed. Patients were aged 62–88 years. Three were receiving haemodialysis, two peritoneal dialysis, two had a kidney transplant and three attended the advanced kidney care clinic. The five most common codes identified were ‘physical exercise’, ‘losing abilities’, ‘mobility’, ‘prevention and safety’ and ‘medical problems’. Themes identified were 1. Mood and memory, 2. Mobility and medical problems, 3. Self-help and supports, 4. Determination, 5. Impact on self and other. The leaflet title was chosen by patients and carers. Figure 1 shows the completed, published leaflet.

Conclusion

This quality improvement project used semi-structured interviews with older patients and carers affected by advanced kidney disease. The main issues they identified in relation to getting older with kidney disease were included in an educational leaflet. Partnership with Kidney Care UK has made the leaflet available across the UK. We hope it will directly address their everyday concerns.

Ganitumab and metformin plus standard neoadjuvant therapy in stage 2/3 breast cancer

I-SPY2 is an adaptively randomized phase 2 clinical trial evaluating novel agents in combination with standard-of-care paclitaxel followed by doxorubicin and cyclophosphamide in the neoadjuvant treatment of breast cancer. Ganitumab is a monoclonal antibody designed to bind and inhibit function of the type I insulin-like growth factor receptor (IGF-1R). Ganitumab was tested in combination with metformin and paclitaxel (PGM) followed by AC compared to standard-of-care alone. While pathologic complete response (pCR) rates were numerically higher in the PGM treatment arm for hormone receptor-negative, HER2-negative breast cancer (32% versus 21%), this small increase did not meet I-SPY's prespecified threshold for graduation. PGM was associated with increased hyperglycemia and elevated hemoglobin A1c (HbA1c), despite the use of metformin in combination with ganitumab. We evaluated several putative predictive biomarkers of ganitumab response (e.g., IGF-1 ligand score, IGF-1R signature, IGFBP5 expression, baseline HbA1c). None were specific predictors of response to PGM, although several signatures were associated with pCR in both arms. Any further development of anti-IGF-1R therapy will require better control of anti-IGF-1R drug-induced hyperglycemia and the development of more predictive biomarkers.

Durvalumab with olaparib and paclitaxel for high-risk HER2-negative stage II/III breast cancer: Results from the adaptively randomized I-SPY2 trial

The combination of PD-L1 inhibitor durvalumab and PARP inhibitor olaparib added to standard paclitaxel neoadjuvant chemotherapy (durvalumab/olaparib/paclitaxel [DOP]) was investigated in the phase II I-SPY2 trial of stage II/III HER2-negative breast cancer. Seventy-three participants were randomized to DOP and 299 to standard of care (paclitaxel) control. DOP increased pathologic complete response (pCR) rates in all HER2-negative (20%-37%), hormone receptor (HR)-positive/HER2-negative (14%-28%), and triple-negative breast cancer (TNBC) (27%-47%). In HR-positive/HER2-negative cancers, MammaPrint ultra-high (MP2) cases benefited selectively from DOP (pCR 64% versus 22%), no benefit was seen in MP1 cancers (pCR 9% versus 10%). Overall, 12.3% of patients in the DOP arm experienced immune-related grade 3 adverse events versus 1.3% in control. Gene expression signatures associated with immune response were positively associated with pCR in both arms, while a mast cell signature was associated with non-pCR. DOP has superior efficacy over standard neoadjuvant chemotherapy in HER2-negative breast cancer, particularly in a highly sensitive subset of high-risk HR-positive/HER2-negative patients.

Synchronous breast carcinoma and peritoneal mesothelioma

Breast cancer may be associated with other primary cancers via germline mutations; however, sporadic occurrences of other malignancies are rare. With increased use of advanced breast cancer imaging, including MRI and PET/CT, other incidental synchronous cancers are increasingly identified. Such cases can represent unique diagnostic and treatment challenges. Here, we present a case of a young woman diagnosed with primary breast cancer who underwent imaging studies identifying an incidental primary peritoneal mesothelioma.

Abstract PS2-07: Outcomes associated with disseminated tumor cells at surgery after neoadjuvant chemotherapy in high-risk early stage breast cancer: The I-SPY SURMOUNT study

Background: Disseminated tumor cells (DTCs) in bone marrow detected after treatment may represent occult residual disease. We enumerated DTCs after neoadjuvant chemotherapy (NACT) in patients (pts) diagnosed with high-risk early stage breast cancer and examined the relationship of these cells with response and survival. Methods: I-SPY SURMOUNT is a sub-study of the I-SPY 2 TRIAL (NCT01042379). Pts enrolled on I-SPY 2, who signed consent for this sub-study, had bone marrow aspirates (BMA) collected after NACT at the time of surgery. DTCs were isolated and enumerated from BMA using immunomagnetic enrichment/flow cytometry (IE/FC). DTCs were defined as EPCAM-positive and CD45-negative nucleated cells. Samples were considered positive using a predetermined threshold of &gt;4 DTCs per mL (Magbanua et al, unpublished data). Pathologic response was assessed using the residual cancer burden (RCB) method at local sites, and pts underwent standard adjuvant therapy if indicated and follow up for recurrence events and death. Relationship of DTCs with clinicopathologic variables was examined using Chi-squared test. Group means were compared using t tests. The log-rank test was used to compare survival curves. Results: A total of 73 patients were enrolled, 51 of whom had successful DTC assessment. The median DTC per mL was 4 (interquartile range 1.2-11.6). 24/51 (47%) were DTC-positive. Clinical characteristics by DTC status are shown in the table. DTC-positive pts were significantly younger (p=0.02) and had larger pretreatment tumors (longest diameter by magnetic resonance imaging) compared to DTC-negative pts (p=0.032). DTCs were not associated with receptor subtype. Thirty pts (41%) achieved a pathologic complete response (pCR). DTCs were not associated with pCR (p= 0.166); however, DTC-positive patients were significantly more likely to have residual cancer (RCB-II/III) after NACT compared to DTC-negative patients (OR 3.3, p=0.037). Median follow up of this cohort was 2.8 years (range: 0.9-4.8). Interim survival analysis showed that DTCs were not significantly correlated with EFS (p=0.6) or DRFS (p=0.41). Conclusions: Detection of DTCs at surgery after NACT is significantly more common in young patients, those with larger tumors, and those with residual disease at surgery. While these associations suggest higher risk for later recurrence, larger studies and longer follow up are necessary to determine if DTCs add prognostic value over pathologic evaluation alone for pts receiving NACT.

Citation Format: Mark Jesus M Magbanua, Laura van 't Veer, Amy Clark, A. Jo Chien, Judy Boughey, Heather Han, Anne Wallace, Heather Beckwith, Minetta Liu, Christina Yau, E. Paul Wileyto, Lamorna Brown Swigart, Jane Perlmutter, Lauren Bayne, Shannon Deluca, Stephanie Yee, Erica Carpenter, Laura Esserman, John Park, Lewis Chodosh, Angela DeMichele. Outcomes associated with disseminated tumor cells at surgery after neoadjuvant chemotherapy in high-risk early stage breast cancer: The I-SPY SURMOUNT study [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS2-07.

Abstract PS6-05: Impact of body mass index on pathological complete response after neoadjuvant chemotherapy: Results from the I-SPY 2 trial

Purpose: Increased body mass index (BMI) is a risk factor for breast cancer and has been associated with poor outcomes in both premenopausal and postmenopausal breast cancer patients. Several retrospective studies have demonstrated higher BMI to be associated with inferior pathological complete response (pCR) to neoadjuvant chemotherapy, yet it remains unclear if this difference is related to chemotherapy underdosing among obese breast cancer patients. We evaluated the association between BMI and response to neoadjuvant chemotherapy (defined by pCR) in the I-SPY 2 trial, an adaptive clinical trial platform enrolling biologically high-risk breast cancer patients (triple negative, human epidermal growth factor receptor 2 (HER2) positive and MammaPrint high-risk) that utilizes standard neoadjuvant therapy regimens with treatment based on actual body weight.

Patients and Methods: From 3/2010 to 11/2016, 989 patients were enrolled in the I-SPY 2 trial, 978 had a recorded baseline BMI prior to treatment and were included in the analysis. Tumor subtypes were defined by hormone receptor and HER2 status. Pretreatment BMI was categorized as obese (BMI&gt;=30 kg/m2), overweight (25=&lt;BMI&lt;30 kg/m2), and normal or underweight (&lt;25 kg/m2) based on World Health Organization criteria. pCR was defined as elimination of detectable invasive cancer in the breast and lymph nodes (ypT0/Tis and ypN0) at the time of surgery. Logistic regression analysis was used to determine associations between BMI and pCR, and we reported odds ratios (OR) and 95% confidence intervals (CI). Event-free survival (EFS) and overall survival (OS) between different BMI categories were examined using Cox proportional hazards regression.

Results: The median age in our study population was 49 years. 35% of patients were normal/underweight, 32% overweight, and 33% obese. Black patients were more likely to be obese (P&lt;0.0001). pCR rates differed significantly by tumor subtype (P&lt;=0.0001) and tumor stage (P=0.0009). pCR rates were 32.8% in normal/underweight, 31.4% in overweight, and 32.5% in obese patients. In univariable analysis, there was no significant difference in pCR with BMI. In multivariate analysis adjusted for race/ethnicity, age, menopausal status, breast cancer subtype, and clinical stage, there was no significant difference in pCR to neoadjuvant chemotherapy for obese compared with normal/underweight patients (OR=1.1, 95%CI: 0.68-1.63, p=0.83), and for overweight compared with normal/underweight (OR=1, 95%CI: 0.64-1.47, p=0.88). We tested for potential interaction between BMI and breast cancer subtype, however, the interaction was not significant in the multivariate model (P=0.09) (Table 1). Multivariate Cox regression showed there was no difference in EFS (p=0.81) or OS (p=0.52) between obese, overweight and normal/underweight breast cancer patients with a median follow-up time of 4.0 years.

Conclusions: There was no difference in pCR rates by BMI with actual body weight based neoadjuvant chemotherapy in this biologically high-risk breast cancer population. In contrast, breast cancer subtype and stage showed predictive value for pCR in this high-risk operable breast cancer population receiving neoadjuvant chemotherapy in the I-SPY 2 clinical trial.

Table 1: pCR rate of different BMI categories by breast cancer subtypes.Breast Cancer SubtypepCRNormal/underweight Frequency (%)OverweightFrequency (%)ObeseFrequency (%)P-valueHR+/HER2+No39 (61.9)27 (61.4)32 (66.7)0.83Yes24 (38.1)17 (38.6)16 (33.3)HR+/HER2-No105 (80.8)116 (89.2)93 (78.8)0.06Yes25 (19.2)14 (10.8)25 (21.2)HR-/HER2+No7 (25.0)11 (35.5)15 (51.7)0.11Yes21 (75.0)20 (64.5)14 (48.3)HR-/HER2-No83 (65.4)58 (55.8)76 (60.8)0.33Yes44 (34.7)46 (44.2)49 (39.2)(HR: hormone receptor, HER2: human epidermal growth factor receptor 2)

Citation Format: Haiyun Wang, Douglas Yee, David Potter, Patricia Jewett, Christina Yau, Heather Beckwith, Allison Watson, Nicholas G O'Grady, Amy Wilson, Susie Brain, I-SPY 2 TRIAL Consortium, Anne Blaes. Impact of body mass index on pathological complete response after neoadjuvant chemotherapy: Results from the I-SPY 2 trial [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS6-05.

Impact of body mass index on pathological complete response following neoadjuvant chemotherapy in operable breast cancer: a meta-analysis

PURPOSE

The impact of an increased body mass index (BMI) on outcomes of neoadjuvant chemotherapy (NACT) in breast cancer remains controversial. The purpose of this study was to analyze the impact of BMI on pathological complete response (pCR) rates for operable breast cancer after NACT.

METHODS

We searched Medline, Embase, and Web of Science database for observational studies and randomized controlled trials that reported the association of BMI with pCR after NACT. We performed a meta-analysis to assess the impact of BMI on pCR rate.

RESULTS

We identified 13 studies including a total of 18,702 women with operable breast cancer who underwent NACT. Two studies were pooled analyses of prospective clinical trials (10,669 patients); the rest were case-control studies (8033 patients). All studies provided data of two BMI groups (BMI < 25 vs. BMI ≥ 25). Pooled analyses demonstrated that overweight/obese women were less likely to achieve pCR after NACT as compared to under-/normal weight women (odds ratio (OR) = 0.80; 95% confidence interval (CI): 0.68-0.93). Eleven studies provided data of three BMI groups (BMI < 25, 25 ≤ BMI < 30, BMI ≥ 30). Based on pooled analyses, both overweight and obese groups were less likely to achieve pCR with NACT as compared to under-/normal weight group, (OR = 0.77, 95% CI 0.65-0.93 and OR = 0.68, 95% CI 0.61-0.77, respectively).

CONCLUSIONS

Overweight and obese breast cancer patients had a lower pCR rate with NACT compared to patients with under-/normal weight. Further prospective studies may help confirm this finding and investigate possible mechanisms.

Emotional health concerns of oncology physicians in the United States: Fallout during the COVID-19 pandemic

INTRODUCTION

Cancer care is significantly impacted by the Coronavirus Disease 2019 (COVID-19) pandemic. Our objective was to evaluate the early effects of the pandemic on the emotional well-being of oncology providers across the United States and explore factors associated with anxiety and depression symptoms.

MATERIALS AND METHODS

A cross-sectional survey was administered to United States cancer-care physicians recruited over a two-week period (3/27/2020-4/10/2020) using snowball-convenience sampling through social media. Symptoms of anxiety and depression were measured using the Patient Health Questionnaire (PHQ-4).

RESULTS

Of 486 participants, 374 (77.0%) completed the PHQ-4: median age was 43 years; 63.2% female; all oncologic specialties were represented. The rates of anxiety and depression symptoms were 62.0% and 23.5%, respectively. Demographic factors associated with anxiety included female sex, younger age, and less time in clinical practice. Perception of inadequate personal protective equipment (68.6% vs. 57.4%, p = 0.03) and practicing in a state with more COVID-19 cases (65.8% vs. 51.1%, p = 0.01) were associated with anxiety symptoms. Factors significantly associated with both anxiety and depression included the degree to which COVID-19 has interfered with the ability to provide treatment to cancer patients and concern that patients will not receive the level of care needed for non-COVID-19 illness (all p-values <0.01).

CONCLUSION

The perceived degree of interference with clinical practice along with personal concerns about COVID-19 were significantly associated with both anxiety and depression among oncology physicians in the United States during the COVID-19 pandemic. Our findings highlight factors associated with and sources of psychological distress to be addressed to protect the well-being of oncology physicians.

Use of 18F-FDG PET/CT as an Initial Staging Procedure for Stage II-III Breast Cancer: A Multicenter Value Analysis

BACKGROUND

Metastatic staging imaging is not recommended for asymptomatic patients with stage I-II breast cancer. Greater distant metastatic disease risk may warrant baseline imaging in patients with stage II-III with high-risk biologic subtypes. NCCN Guidelines recommend considering CT of the chest, abdomen, and pelvis (CT CAP) and bone scan in appropriate patients. CT CAP and bone scan are considered standard of care (SoC), although PET/CT is a patient-centered alternative.

METHODS

Data were available for 799 high-risk patients with clinical stage II-III disease who initiated screening for the I-SPY2 trial at 4 institutions. A total of 564 complete records were reviewed to compare PET/CT versus SoC. Costs were determined from the payer perspective using the national 2018 Medicare Physician Fee Schedule and representative reimbursements to the University of California, San Francisco (UCSF). Incremental cost-effectiveness ratio (ICER) measured cost of using PET/CT per percent of patients who avoided a false-positive (FP).

RESULTS

The de novo metastatic disease rate was 4.6%. Imaging varied across the 4 institutions (P<.0001). The FP rate was higher using SoC versus PET/CT (22.1% vs 11.1%; P=.0009). Mean time between incidental finding on baseline imaging to FP determination was 10.8 days. Mean time from diagnosis to chemotherapy initiation was 44.3 days with SoC versus 37.5 days with PET/CT (P=.0001). Mean cost per patient was $1,132 (SoC) versus $1,477 (PET/CT) using the Medicare Physician Fee Schedule, with an ICER of $31. Using representative reimbursements to UCSF, mean cost per patient was $1,236 (SoC) versus $1,073 (PET/CT) for Medicare, and $3,083 (SoC) versus $1,656 (PET/CT) for a private payer, with ICERs of -$15 and -$130, respectively.

CONCLUSIONS

Considerable variation exists in metastatic staging practices. PET/CT reduced FP risk by half and decreased workup of incidental findings, allowing for earlier treatment start. PET/CT may be cost-effective, and at one institution was shown to be cost-saving. Better alignment is needed between hospital pricing strategies and payer coverage policies to deliver high-value care.

Sources of Medical Information for Oncology Physicians During the COVID-19 Pandemic: Results From a National Cross-Sectional Survey

Because the coronavirus disease 2019 (COVID-19) has completely transformed the accepted norms and approaches to cancer care delivery in the United States, we sought to understand the sources of medical information that oncology physicians seek and trust. We recruited 486 oncology physicians to an anonymous cross-sectional online survey through social media from March 27, 2020, to April 10, 2020, with 79.2% reporting their sources of medical information during the COVID-19 pandemic. We found a diverse array of reported sources for COVID-19 information that most commonly included professional societies (90.7%), hospital or institutional communications (88.6%), and the Centers for Disease Control and Prevention (69.9%); however, trust in these sources of information varied widely, with professional societies being the most trusted source. These results highlight the important role that professional societies, hospitals, and the Centers for Disease Control and Prevention play in ensuring dissemination of consistent, high-quality practice recommendations for oncology physicians.

Cancer Management During the COVID-19 Pandemic in the United States: Results From a National Physician Cross-sectional Survey

OBJECTIVES

The coronavirus disease 2019 (COVID-19) has significantly impacted health care delivery across the United States, including treatment of cancer. We aim to describe the determinants of treatment plan changes from the perspective of oncology physicians across the United States during the COVID-19 pandemic.

METHODS

Participants were recruited to an anonymous cross-sectional online survey of oncology physicians (surgeons, medical oncologists, and radiation oncologists) using social media from March 27 to April 10, 2020. Physician demographics, practice characteristics, and cancer treatment decisions were collected.

RESULTS

The analytic cohort included 411 physicians: 241 (58.6%) surgeons, 106 (25.8%) medical oncologists, and 64 (15.6%) radiation oncologists. In all, 38.0% were practicing in states with 1001 to 5000 confirmed COVID-19 cases as of April 3, 2020, and 37.2% were in states with >5000 cases. Most physicians (N=285; 70.0% of surgeons, 64.4% of medical oncologists, and 73.4% of radiation oncologists) had altered cancer treatment plans. Most respondents were concerned about their patients' COVID-19 exposure risks, but this was the primary driver for treatment alterations only for medical oncologists. For surgeons, the primary driver for treatment alterations was conservation of personal protective equipment, institutional mandates, and external society recommendations. Radiation oncologists were primarily driven by operational changes such as visitor restrictions.

CONCLUSIONS

The COVID-19 pandemic has caused a majority of oncologists to alter their treatment plans, but the primary motivators for changes differed by oncologic specialty. This has implications for reinstitution of standard cancer treatment, which may occur at differing time points by treatment modality.

Association of Event-Free and Distant Recurrence-Free Survival With Individual-Level Pathologic Complete Response in Neoadjuvant Treatment of Stages 2 and 3 Breast Cancer: Three-Year Follow-up Analysis for the I-SPY2 Adaptively Randomized Clinical Trial

Importance

Pathologic complete response (pCR) is a known prognostic biomarker for long-term outcomes. The I-SPY2 trial evaluated if the strength of this clinical association persists in the context of a phase 2 neoadjuvant platform trial.

Objective

To evaluate the association of pCR with event-free survival (EFS) and pCR with distant recurrence-free survival (DRFS) in subpopulations of women with high-risk operable breast cancer treated with standard therapy or one of several novel agents.

Design, Setting, and Participants

Multicenter platform trial of women with operable clinical stage 2 or 3 breast cancer with no prior surgery or systemic therapy for breast cancer; primary tumors were 2.5 cm or larger. Women with tumors that were ERBB2 negative/hormone receptor (HR) positive with low 70-gene assay score were excluded. Participants were adaptively randomized to one of several different investigational regimens or control therapy within molecular subtypes from March 2010 through 2016. The analysis included participants with follow-up data available as of February 26, 2019.

Interventions

Standard-of-care neoadjuvant therapy consisting of taxane treatment with or without (as control) one of several investigational agents or combinations followed by doxorubicin and cyclophosphamide.

Main Outcomes and Measures

Pathologic complete response and 3-year EFS and DRFS.

Results

Of the 950 participants (median [range] age, 49 [23-77] years), 330 (34.7%) achieved pCR. Three-year EFS and DRFS for patients who achieved pCR were both 95%. Hazard ratios for pCR vs non-pCR were 0.19 for EFS (95% CI, 0.12-0.31) and 0.21 for DRFS (95% CI, 0.13-0.34) and were similar across molecular subtypes, varying from 0.14 to 0.18 for EFS and 0.10 to 0.20 for DRFS.

Conclusions and Relevance

The 3-year outcomes from the I-SPY2 trial show that, regardless of subtype and/or treatment regimen, including 9 novel therapeutic combinations, achieving pCR after neoadjuvant therapy implies approximately an 80% reduction in recurrence rate. The goal of the I-SPY2 trial is to rapidly identify investigational therapies that may improve pCR when validated in a phase 3 confirmatory trial. Whether pCR is a validated surrogate in the sense that a therapy that improves pCR rate can be assumed to also improve long-term outcome requires further study.

Trial Registration

ClinicalTrials.gov Identifier: NCT01042379.

Emotional health concerns of oncology physicians in the United States: fallout during the COVID-19 pandemic

INTRODUCTION

Cancer care is significantly impacted by the Coronavirus Disease 2019 (COVID-19) pandemic. Our objective was to evaluate the effect of the pandemic on the emotional well-being of oncology providers across the United States and explore factors associated with anxiety and depression symptoms.

METHODS AND MATERIALS

A cross-sectional survey was administered to United States cancer-care physicians recruited over a two-week period (3/27/2020-4/10/2020) using snowball-convenience sampling through social media. Symptoms of anxiety and depression were measured using the Patient Health Questionnaire (PHQ-4).

RESULTS

Of 486 participants, 374 (77.0%) completed the PHQ-4: mean age 45.7 +/- 9.6 years; 63.2% female; all oncologic specialties were represented. The rates of anxiety and depression symptoms were 62.0% and 23.5%, respectively. Demographic factors associated with anxiety included female sex, younger age, and less time in clinical practice. Perception of inadequate PPE (68.6% vs. 57.4%, p=0.03) and practicing in a state with more COVID-19 cases (65.8% vs. 51.1%, p=0.01) were associated with anxiety symptoms. Factors significantly associated with both anxiety and depression included: degree to which COVID-19 has interfered with the ability to provide treatment to cancer patients and concern that patients will not receive the level of care needed for non-COVID-19 illness (all p-values <0.01).

CONCLUSION

The prevalence of anxiety and depression symptoms among oncology physicians in the United States during the COVID-19 pandemic is high. Our findings highlight factors associated with and sources of psychological distress to be addressed to protect the well-being of oncology physicians.

Abstract P3-08-39: Pathological complete response following neoadjuvant chemotherapy in operable breast cancer patients: Is obesity a predictive factor?

Background: Overweight and obesity are associated with greater disease-specific mortality and overall mortality in cancer patients. Neoadjuvant chemotherapy offers a unique setting to assess breast cancer chemosensitivity in vivo, and thus can help us understand why obesity is associated with poor prognosis in breast cancer patients. The effect of increased Body mass index (BMI) in breast cancer patients undergoing neoadjuvant chemotherapy remains controversial.

Purpose: To review and analyze the association between BMI and pathological complete response (pCR) rate for operable breast cancer after neoadjuvant chemotherapy (NACT).

Data sources: Pub Med and Cochrane Database to December 31, 2018

Study selection: We included observational studies and randomized trials that evaluated association of BMI with pCR in operable breast cancer patients that underwent NACT.

Data extraction and analysis: Two authors independently extracted data and rated study quality; discrepancies were resolved through consensus.

Results: We identified 13 studies including a total of 14179 women with operable breast cancer who underwent NACT. Among them, two studies were pooled analysis of prospective clinical trials (10622 patients); the rest were retrospective case control studies (3557 patients). The influence of categorical BMI on pCR after NACT was analyzed. All studies provided data with BMI divided into two subgroups (BMI &lt;25 vs BMI ≥25). Pooled analyses demonstrated overweight/obese women were less likely to achieve pCR after NACT when compared with women in the under-/normal weight group, OR=0.77 (95% CI: 0.71, 0.84). 10 studies provided data with BMI divided into three groups (BMI &lt;25, 25 ≤BMI&lt; 30, BMI ≥30). Pooled analyses showed compared to under-/normal weight group, both overweight (OR= 0.81 95% CI: 0.72, 0.89) and obese (OR = 0.62 95% CI: 0.54, 0.69) groups were less likely to achieve pCR to NACT. We were not able to perform pooled analysis of association between BMI and pCR in subtypes of breast cancer based on hormone receptor and HER-2 status; as only two studies provided these data and breast cancer subtypes were defined differently. There was moderate heterogeneity in between these studies.

Conclusion: Overweight and obese breast cancer patients had lower pCR rates compared to those with under-/normal weight. Further prospective studies may help to confirm this finding and to clarify underlying mechanisms.

Citation Format: Haiyun Wang, Shijia Zhang, Douglas Yee, Heather Beckwith, David Potter, Anne Blaes. Pathological complete response following neoadjuvant chemotherapy in operable breast cancer patients: Is obesity a predictive factor? [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 P3-08-39.

Abstract P5-15-01: The use of 18F-FDG PET/CT as an initial staging procedure for stage II-III breast cancer reduces false positives, costs, and time to treatment: A multicenter value analysis in the I-SPY2 trial

Introduction: Diagnostic metastatic staging imaging (SI) for asymptomatic stage I-II patients (pts) is not routinely recommended, but is warranted in stage II-III pts with high risk biological subtypes, where previous trials have shown up to a 15% rate of de novo metastatic disease. NCCN guidelines endorse CT CAP and bone scan (STD) for stage III pts, but not PET/CT, and PET/CT is not covered in most parts of the country. We present data on the performance and value of PET/CT.

Methods: Data were available for 799 high risk clinical stage II-III pts screened for I-SPY2 at UCSF, Uminn, UAB, and Georgetown. Of these, 564 pts ranging in age from 25-81 (median = 48) had complete records that were retrospectively reviewed for SI and potential false positives (FP), defined as incidental findings on SI proven benign by subsequent workup. Economic evaluation was conducted from the payer perspective using the mean national 2018 Medicare Physician Fee Schedule and representative costs from the UCSF billing department. The incremental cost effectiveness ratio (ICER) measured the cost of using PET/CT per percent patient (pt) who avoided a FP.

Results: The rate of de novo metastatic disease was 4.8% (38/799), range 3.6-6.4%. Of the 564 pts with complete records, diagnostic SI varied significantly among the four sites (p &lt; 0.0001). STD was used for most pts at UAB (92.8%, 141/152) and Georgetown (85.7%, 54/63), while PET/CT was used for most pts at UCSF (86.6%, 226/261) and Uminn (63.6%, 56/88). Chest X-ray was used for 29.5% (26/88) at Uminn. There were significantly more pts with FP in the group that received STD (22.1%, 51/231) vs. PET/CT (11.1%, 33/298) (p &lt; 0.05). Mean time between incidental finding on SI to determination of FP was 10.8 days. When controlling for institution, mean time from cancer diagnosis to initiation of neoadjuvant chemotherapy was significantly different between STD (44.3 days) and PET/CT (37.5 days) groups (p &lt; 0.05). When aggregating the four sites using mean costs from the 2018 Medicare Physician Fee Schedule, the mean cost/pt was $1132 for STD vs. $1477 for PET/CT. The mean increase in price from baseline SI costs due to FP workup was $216 (23.6%) for STD vs. $65 (4.6%) for PET/CT. The ICER was $31 per percent pt who avoided a FP. When analyzing UCSF pts alone using representative reimbursements from Medicare, the mean cost/pt was $1236 for STD vs. $1081 for PET/CT; using representative reimbursements from Anthem Blue Cross, the mean cost/pt was $3080 for STD vs. $1662 for PET/CT. The ICERs were -$10 and -$95 per percent pt who avoided a FP, respectively.

Conclusion: As compared to STD metastatic staging workup, PET/CT added value by decreasing FP two-fold. This reduced direct costs of FP workup procedures that took a mean time of 10.8 days to resolve. PET/CT also accelerated treatment start. Reducing the chance of FP workup for metastatic disease is of enormous value to pts. Our data establish the value of PET/CT for staging in our high risk clinical stage II-III trial population and highlight the need for alignment between hospital pricing strategies and payer coverage policies in order to deliver high value care to pts.

Citation Format: Hyland CJ, Varghese F, Yau C, Beckwith H, Khoury K, Varnado W, Hirst G, Chien J, Yee D, Isaacs C, Forero-Torres A, Esserman L, Melisko M, I-SPY2 Consortium. The use of 18F-FDG PET/CT as an initial staging procedure for stage II-III breast cancer reduces false positives, costs, and time to treatment: A multicenter value analysis in the I-SPY2 trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-15-01.

Abstract P2-14-01: The impact of local therapy on locoregional recurrence in women with high risk breast cancer in the neoadjuvant I-SPY2 TRIAL

Background: In women with breast cancer receiving neoadjuvant chemotherapy, residual cancer burden (RCB) predicts distant recurrence and survival. In those with high risk tumors, locoregional recurrence (LRR) remains a concern, and has been associated with type of local therapy received. We evaluated the impact of local therapy on LRR in the ISPY-2 TRIAL.

Methods: Data were analyzed in Stata 14.2, using Chi2 test, log rank test, and a Cox proportional hazards model. RCB was considered a categorical variable (0/1 versus 2/3), as described in prior publications. Breast surgery categories were lumpectomy +/- radiotherapy, or mastectomy +/- radiotherapy. Axillary surgery was defined as sentinel lymph node (SLN) surgery (≤6 nodes removed) or axillary dissection (&gt;6 nodes).

Results: Follow up data from the I-SPY2 TRIAL were available for 630 patients (median follow up 2.76 yrs, range 0.4-7.2). Type of local therapy was significantly associated with clinical stage at presentation, with stage III patients most frequently undergoing mastectomy + radiation (p&lt;0.001). Women with higher RCB were more likely to undergo mastectomy than those with lower RCB (61.3% vs 48.8% mastectomy rate, p=0.002), and more likely to receive adjuvant radiotherapy (62.0% vs 53.9%, p=0.048). There was no association between clinical stage, type of surgery, or radiotherapy and LRR (Table). Higher RCB was significantly associated with LRR, with 3 year locoregional recurrence free rate of 95.1% in RCB 0/1 versus 89.9% in RCB 2/3 (p=0.003).

In a Cox model adjusting for clinical stage, tumor subtype, surgical therapy, RCB status, nodal radiation, and age, significant predictors for LRR were tumor subtype and RCB status. Hazard ratio (HR) for LRR in those with RCB 0/1 was 0.39 compared to those with RCB 2/3 (95% CI 0.17-0.87, p=0.021). There was no difference in LRR between breast conservation and mastectomy; within the breast conservation group, those who had lumpectomy alone had higher hazard of LRR compared to those having lumpectomy + radiation (HR 3.1, 95% CI 1.1-9.2, p=0.043).

Conclusions: Extent of surgical therapy was not associated with local tumor control, regardless of advanced tumor stage at presentation. Rather, tumor biology and response to therapy were the best predictors of LRR. These data highlight the opportunity to minimize the morbidity of extensive surgical therapy for patients with excellent response to systemic therapy.

LRR rates by clinical features and treatment status FrequencyLRR RateP valueClinical Stage  0.5I240 (47.5%)5.8% II185 (36.6%)8.7% III80 (15.8%)6.3% Tumor Subtype  0.014ER+PR+Her2-161 (26.4%)3.1% ER+PR-Her2-56 (9.2%)3.6% Her2+176 (28.9%)6.3% Triple negative216 (35.5%)11.1% Local therapy  0.169Lumpectomy85 (13.5%)11.8% Lumpectomy with radiation198 (31.4%)5.6% Mastectomy173 (27.5%)5.2% Mastectomy with radiation174 (27.6%)8.6% Axillary surgery  0.23None5 (0.8%)20% SLN329 (52.2%)5.8% ALND296 (47%)8.5% Axillary radiation  0.535Yes42 (6.7%)9.5% No588 (93.3%)7.0% Axillary management  0.2No surgery or radiation5 (0.8%)20.0% SLN312 (50%)5.3% SLN+Axillary radiation17 (2.7%)8.3% ALND271 (43%)10.3% ALND+Axillary radiation25 (4%)5.4% RCB  0.0020/1293 (50.1%)3.8% 2/3292 (49.9%)10.3% 

Citation Format: Silverstein J, Suleiman L, Yau C, Price ER, Singhrao R, Yee D, DeMichele A, Isaacs C, Albain KS, Chien AJ, Forero-Torres A, Wallace AM, Pusztai L, Ellis ED, Elias AD, Lang JE, Lu J, Han HS, Clark AS, Korde L, Nanda R, Northfelt DW, Khan QJ, Viscusi RK, Euhus DM, Edmiston KK, Chui SY, Kemmer K, Wood WC, Park JW, Liu MC, Olopade O, Leyland-Jones B, Tripathy D, Moulder SL, Rugo HS, Schwab R, Lo S, Helsten T, Beckwith H, I-SPY 2 TRIAL Consortium, Berry DA, Asare SM, Esserman LJ, Boughey JC, Mukhtar RA. The impact of local therapy on locoregional recurrence in women with high risk breast cancer in the neoadjuvant I-SPY2 TRIAL [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-14-01.

Abstract P2-07-03: Refining neoadjuvant predictors of three year distant metastasis free survival: Integrating volume change as measured by MRI with residual cancer burden

Background: Patients achieving a pathologic complete response (pCR) following neoadjuvant therapy have significantly improved event-free survival relative to those who do not; and pCR is an FDA-accepted endpoint to support accelerated approval of novel agents/combinations in the neoadjuvant treatment of high risk early stage breast cancer. Previous studies have shown that recurrence risk increased with increasing burden of residual disease (as assessed by the RCB index). As well, these studies suggest that patients with minimum residual disease (RCB-I class) also have favorable outcomes (comparable to those achieving a pCR) within high risk tumor subtypes. In this study, we assess whether integrating RCB with MRI functional tumor volume (FTV), which in itself is prognostic, can improve prediction of distant recurrence free survival (DRFS); and identify a subset of patients with minimal residual disease with comparable DRFS as those who achieved a pCR. Imaging tools can then be used to identify the subset that will do well early and guide the timing of surgical therapy.

Method: We performed a pooled analysis of 596 patients from the I-SPY2 TRIAL with RCB, pre-surgical MRI FTV data and known follow-up (median 2.5 years). We first assessed whether FTV predicts residual disease (pCR or pCR/RCB-I) using ROC analysis. We applied a power transformation to normalize the pre-surgical FTV distribution; and assessed its association with DRFS using a bi-variate Cox proportional hazard model adjusting for HR/HER2 subtype. We also fitted a bivariate Cox model of RCB index adjusting for subtype; and assessed whether adding pre-surgical FTV to this model further improves association with DRFS using a likelihood ratio (LR) test. For the Cox modeling, penalized splines approximation of the transformed FTV and RCB index with 2 degrees of freedom was used to allow for non-linear effects of FTV and RCB on DRFS.

Result: Pre-surgical MRI FTV is significantly associated with DRFS (Wald p&lt;0.00001), and more effective at predicting pCR/RCB-I than predicting pCR alone (AUC: 0.72 vs. 0.65). Larger pre-surgical FTV remains associated with worse DRFS adjusting for subtype (Wald p &lt;0.00001). The RCB index is also significantly associated with DRFS adjusting for subtype (Wald p&lt;0.00001). Adding FTV to a model containing RCB and subtype further improves association with DRFS (LR p=0.0007). RCB-I patients have excellent DRFS (94% at 3 years compared to 95% in the pCR group). Efforts are underway to identify an optimal threshold for dichotomizing pre-surgical FTV and FTV change measures for use in combination with pCR/RCB-I class to generate integrated RCB (iRCB) groups as a composite predictor of DRFS.

Conclusion: Pre-surgical MRI FTV is effective at predicting minimal residual disease (RCB0/I) in the I-SPY 2 TRIAL. Despite the association between FTV and RCB, FTV appears to provide independent added prognostic value (to RCB and subtype), suggesting that integrating MRI volume measures and RCB into a composite predictor may improve DRFS prediction.

Citation Format: Hylton NM, Symmans WF, Yau C, Li W, Hatzis C, Isaacs C, Albain KS, Chen Y-Y, Krings G, Wei S, Harada S, Datnow B, Fadare O, Klein M, Pambuccian S, Chen B, Adamson K, Sams S, Mhawech-Fauceglia P, Magliocco A, Feldman M, Rendi M, Sattar H, Zeck J, Ocal I, Tawfik O, Grasso LeBeau L, Sahoo S, Vinh T, Yang S, Adams A, Chien AJ, Ferero-Torres A, Stringer-Reasor E, Wallace A, Boughey JC, Ellis ED, Elias AD, Lang JE, Lu J, Han HS, Clark AS, Korde L, Nanda R, Northfelt DW, Khan QJ, Viscusi RK, Euhus DM, Edmiston KK, Chui SY, Kemmer K, Wood WC, Park JW, Liu MC, Olopade O, Tripathy D, Moulder SL, Rugo HS, Schwab R, Lo S, Helsten T, Beckwith H, Haugen PK, van't Veer LJ, Perlmutter J, Melisko ME, Wilson A, Peterson G, Asare AL, Buxton MB, Paoloni M, Clennell JL, Hirst GL, Singhrao R, Steeg K, Matthews JB, Sanil A, Berry SM, Abe H, Wolverton D, Crane EP, Ward KA, Nelson M, Niell BL, Oh K, Brandt KR, Bang DH, Ojeda-Fournier H, Eghtedari M, Sheth PA, Bernreuter WK, Umphrey H, Rosen MA, Dogan B, Yang W, Joe B, I-SPY 2 TRIAL Consortium, Yee D, Pusztai L, DeMichele A, Asare SM, Berry DA, Esserman LJ. Refining neoadjuvant predictors of three year distant metastasis free survival: Integrating volume change as measured by MRI with residual cancer burden [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-07-03.

Abstract P1-12-06: Endothelial dysfunction in breast cancer survivors on aromatase inhibitors (AIs) over time

Endothelial dysfunction in breast cancer survivors on aromatase inhibitors (AIs) over time

Background: AIs reduce breast cancer-related mortality however they may increase cardiovascular (CV) risk. Our previously published cross-sectional study suggested women on AIs were more likely to have endothelial dysfunction when measured by EndoPAT ratio as compared to healthy postmenopausal women. Reductions in EndoPAT ratio (&lt;1.67) and small artery elasticity (SAE) and increases in highly sensitive C-reactive protein (CRP) are associated with worsening endothelial dysfunction and increased cardiovascular events. We present data from a longitudinal pilot study looking at endothelial dysfunction over time in women on AIs.

Methods: Fourteen women with locally advanced breast cancer prescribed an AI underwent vascular testing at baseline (pre-AI) and at 6 months. Subjects with tobacco use, hypertension or hyperlipidemia were excluded. Consented subjects underwent biomarker analysis and radial artery pulse wave analysis using the HDI/Pulse Wave CR-2000 CV Profiling System and pulse contour analysis using the Endo-PAT2000 system. Biomarkers were obtained using a fasting blood draw to evaluate the following lipids and inflammatory markers: serum ultrasensitive estradiol, serum glucose, total cholesterol (TC), low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), and triglycerides (TG), CRP, plasminogen-activator 1 (PA1), and tissue-type plasminogen activator (tPA). Changes between baseline and follow-up using Wilcoxon signed-rank tests were analyzed.

Results: Mean baseline age was 59 years and median body mass index was 26.5 kg/m2. Median systolic blood pressure and total cholesterol were 120/70 mm/Hg and 228 mg/dL, respectively. Baseline ultrasensitive estradiol levels were 7 pg/mL and hsCRP was 2.45 mg/dL. Prior to AI therapy, endoPAT ratio was 2.18 (1.19, 2.43). After six months, EndoPAT ratio declined to a median 1.12 (0.85, 1.86) (p=0.045). There were no statistically significant changes in serum glucose, TC, LDL, HDL, hsCRP, PA1 and tPA. HsCRP remained elevatedat median 2.98 mg/L. At six months, estradiol levels decreased to a median of 2 pg/mL (p=0.052), however, there appeared to be no linear association between changes in EndoPAT and estradiol (p=0.91).

Conclusion: Breast cancer survivors on AIs have endothelial dysfunction, a predictor of adverse CV disease. These changes develop while on AIs. Underlying pathophysiology requires further evaluation.

Cardiovascular markersMeasuresBaselineFollow-Up at 6 MonthsChangeP-valueBMI (kg/m2)26.5 (24.4, 31.6)27.1 (23.9, 32.9)0.5 (0.0, 1.3)0.056SBP (mmHg)120 (115, 124)123 (114, 127)-0.8 (-7.4, 3.6)0.91DBP (mmHg)70 (61, 73)69 (62, 71)0.0 (-3.0, 2.6)0.88Total Cholesterol (mg/dL)228 (202, 244)213 (210, 229)-1 (-18, 27)0.70HDL (mg/dL)64 (58, 69)73 (61, 77)2 (-3, 14)0.44LDL (mg/dL)143 (121, 159)129 (120, 142)6 (-11, 14)0.65Estradiol (pg/mL)7 (4, 15)2 (2, 3)-8 (-12, -3)0.05hsCRP (mg/dL)2.45 (1.14, 6.07)2.98 (0.90, 4.81)-8 (-12, -3)0.85EndoPAT Ratio2.18 (1.19, 2.43)1.12 (0.85, 1.86)-0.16 (-1.45, -0.02)0.0451.Summaries shown are median (1st quartile, 3rd quartile).

Citation Format: Blaes AH, Petersen A, Beckwith H, Potter D, Florea N, Yee D, Vogel R, Duprez D. Endothelial dysfunction in breast cancer survivors on aromatase inhibitors (AIs) over time [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-12-06.

Abstract P3-10-14: LIV-1 expression in primary breast cancers in the I-SPY 2 TRIAL

Background: LIV-1 is an estrogen-inducible gene that has been implicated in epidermal-to-mesenchymal transition (EMT) in preclinical models of progression and metastasis. Its expression is associated with node-positivity in breast cancer; and has been detected in a variety of cancer types, including estrogen receptor positive breast cancers. SGN-LIV1A is a novel antibody drug conjugate targeting LIV-1 that is currently being evaluated in the I-SPY 2 TRIAL. In this pilot study, we evaluated LIV-1 levels by IHC within HR/HER2/MammaPrint (MP) defined subtypes among patients screening for the I-SPY 2 TRIAL and its correlation to microarray assessed LIV-1 expression levels.

Method: In a pilot study, LIV-1 IHC staining was performed by Quest Diagnostics on the pre-treatment samples of 38 patients screening for the I-SPY 2 TRIAL. Pre-treatment expression data generated on a custom Agilent 44K platform was also available. We summarized the LIV-1 H-Scores and percent (%)-positivity across the population and within HR/HER2/MP subtypes; and we assessed the Pearson correlation between LIV-1 H-Score and LIV-1 gene expression levels. In addition, we compared the pre-treatment LIV-1 expression levels within HR/HER2/MP subtypes across I-SPY 2 TRIAL patients from completed arms and their relevant controls (n=989) using ANOVA and post-hoc Tukey tests. Our statistics are descriptive rather than inferential; and does not take into account multiplicities of other biomarkers outside of this study.

Results: Of the 38 patients evaluated, 37 have LIV-1 %-positivity &gt; 0; and 18 (47%) have 100% LIV1 positivity. The median LIV-1 H-Score is 200; and 89% of patients (34/38) have moderate/high LIV-1 staining (with H-Score≥100). Of the 34 patients who proceeded onto the trial (and have known HR/HER2/MP status), 9 are triple negative, 19 are HR+HER2-, and 6 are HER2+. Due to our small sample size, we did not further subset the triple negative and HER2+ cases; but within the HR+HER2- patients, 10 are MP1 compared to 9 who are MP2 class. LIV1 H-Score appears highest within the HR+HER2-MP1 cases (median: 290), followed by the HER2+ (median: 216), then the HR+HER2-/MP2 (median: 155), and the TN (median: 120) subtype. LIV1 H-score is significantly correlated with LIV-1 mRNA expression levels (Rp=0.79, p&lt;0.0001). Consistent with these observations, LIV-1 pre-treatment expression levels are significantly higher in the HR+HER2-MP1 group relative to all other HR/HER2/MP defined subtypes (Tukey HSD p &lt; 0.0001) across the I-SPY 2 TRIAL population. The HR+HER2+MP1 group also have high LIV-1 expression levels.

Conclusion: Our result suggest that although LIV-1 expression differs by subtype, it is expressed at a moderate/high level in the majority of patients. The good correlation between IHC and array-based LIV-1 expression levels enables us to leverage the entire existing I-SPY 2 dataset and confirm the high rates of LIV-1 expression across the I-SPY 2 population. Further studies to evaluate LIV-1 expression as a biomarker of response to LIV-1 targeting therapies for the neoadjuvant treatment of breast cancer are warranted and ongoing in I-SPY 2.

Citation Format: Yau C, Brown-Swigart L, Asare S, I-SPY 2 TRIAL Consortium, Esserman L, van' t Veer L, Beckwith H, Forero A, Rugo H. LIV-1 expression in primary breast cancers in the I-SPY 2 TRIAL [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-10-14.

Abstract 5839: Growth hormone receptor (GHR) expression confers resistance to ruxolitinib in endocrine-resistant breast cancer cells

More than 30% of patients with early-stage estrogen receptor-positive breast cancer (ER+) treated with adjuvant endocrine therapy will relapse within fifteen years and all patients with metastatic breast cancer expressing ER eventually acquire resistance to antiestrogen therapy. The insulin-like growth factor 1 (IGF-1) and its receptor (IGF-1R) are involved in the development of resistance to endocrine therapies such as tamoxifen. The IGF-1/growth hormone (GH) signaling axis has been implicated as a mitogenic pathway in the development and progression of breast carcinogenesis. Preclinical data demonstrate that blockade of the IGF-1R inhibits breast cancer growth, progression, and drug resistance. Unfortunately, IGF-1R targeted therapies have failed to show a benefit in prolonging either disease-free or overall survival in clinical trials. IGF-1R inhibition results in upregulation of GH due to disruption of a negative feedback pathway. We propose GH is able to stimulate mitogenic pathways independently of IGF-IR and the GHR is a potential therapeutic target in endocrine-resistant breast cancers. Tamoxifen-resistant (TamR) and long-term estrogen deprived (LTED) cells were derived from parental MCF-7L and T47D estrogen receptor-positive breast cancer cells. The endocrine-resistant cell lines express increased levels of growth hormone receptor (GHR) mRNA compared to the parental cell lines from which they were derived when measured by RT-PCR. TamR and LTED cell lines have reduced IGF-1R expression, but continue to phosphorylate insulin receptor substrate 1(IRS-1) downstream of IGF-1R. In these endocrine-resistant cells, GH treatment activates protein kinase B (Akt), phosphoinositide 3-kinase (PI3K), and mitogen activated protein kinase (MAPK) pathways in the absence of IGF-1. To determine if GHR signals through janus kinase-2 (JAK-2) in these cells, we treated MCF-7L and T47D TamR cells with 500 nM GH, which resulted in JAK-2 phosphorylation. To examine growth effects, we treated cells with the JAK-2 inhibitor ruxolitinib. Both MCF-7L and T47D endocrine-resistant cell lines treated with ruxolitinib have increased IC50 values compared to their parental counterparts. The MCF-7L parental cells had an IC50 value of 6.7 µM compared to 20 µM and 21.7 µM in TamR and LTED cells, respectively. The T47D parental cells had an IC50 value of 28.6 µM whereas the IC50 of T47D TamR cells was 45 µM. These data indicate endocrine-resistant breast cancer cell lines with elevated GHR expression have decreased sensitivity to JAK-2 inhibition. Based on these results, GHR and its downstream signaling should be considered as a target in the development of novel therapeutics to treat breast cancers that are resistant to traditional endocrine therapies.

Citation Format: Anja N. Holtz, Douglas Yee, Heather Beckwith. Growth hormone receptor (GHR) expression confers resistance to ruxolitinib in endocrine-resistant breast cancer cells [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 5839.

Distribution of 21-Gene Recurrence Scores Among Breast Cancer Histologic Subtypes

CONTEXT

- The 21-gene recurrence score (RS) provides a probability of distant recurrence for estrogen receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancers. The utility of RS for rarer histologic subtypes of breast cancer is uncertain.

OBJECTIVE

- To determine the distribution of RS among various histologic subtypes using a population database.

DESIGN

- Women between the ages of 18 and 75 with estrogen receptor-positive, HER2-negative breast cancer and known RS results were identified using the Surveillance, Epidemiology, and End Results database. Recurrence scores were categorized into risk groups using both traditional and Trial Assigning Individualized Options for Treatment cutoffs. Multivariable logistic regression was used to determine factors associated with high-risk RS.

RESULTS

- We identified 45 618 patients with stage I to III, estrogen receptor-positive, HER2-negative breast cancer who had RS available. Overall, 3087 (7%) and 6337 (14%) of cancers were classified as high risk based on traditional and Trial Assigning Individualized Options for Treatment RS cutoffs, respectively. The proportion of high-risk RS ranged from 1% (tubular, 2 of 225) to 68% (medullary, 13 of 19) and 4% (tubular, 10 of 225) to 79% (medullary, 15 of 19) for traditional and Trial Assigning Individualized Options for Treatment cutoffs, respectively. Based on multivariable logistic regression (excluding medullary), subtypes other than invasive ductal carcinoma and papillary carcinoma were significantly associated with lower RS. The strongest predictors of a high-risk RS were higher tumor grade and negative progesterone receptor status.

CONCLUSIONS

- We identified distinct distributions of RS among different histologic subtypes of breast cancer. Excluding medullary carcinoma, histologic subtypes other than invasive ductal carcinoma and papillary carcinoma all predict lower RS.

Vascular function in breast cancer survivors on aromatase inhibitors: a pilot study

PURPOSE

Aromatase inhibitors (AI) have been shown to reduce breast cancer-related mortality in women with estrogen positive (ER+) breast cancer. The use of AIs, however, has been associated with higher rates of hypertension, hyperlipidemia, and cardiovascular (CV) events.

METHODS

A cross-sectional study of 25 healthy postmenopausal women and 36 women with curative intent breast cancer on an AI was performed to assess endothelial dysfunction, an indicator of risk for CV events. Consented subjects underwent vascular testing using the HDI/Pulse Wave CR-2000 Cardiovascular Profiling System and the EndoPAT2000 system.

RESULTS

Mean age was 61.7 and 59.6 years (cases, controls). Most subjects were Caucasian and overweight. Controls had a lower mean systolic blood pressure (128.6 mmHg vs. 116.2 mmHg, p = 0.004). Median estradiol levels were reduced in cases (2 vs. 15 pg/ml, p < 0.0001). EndoPAT ratio (0.8 vs. 2.7, p < 0.0001) was significantly reduced in cases as compared to controls. Median large artery elasticity (12.9 vs. 14.6 ml/mmHg × 10, p = 0.12) and small artery elasticity (5.2 vs. 7.0 ml/mmHg × 100, p = 0.07) were also reduced though not statistically significant. There was no correlation between use of chemotherapy, radiation therapy, type of AI, or duration of AI use and endothelial function. When adjusting for differences in blood pressure, results remained significant.

CONCLUSION

Breast cancer cases on AIs have reductions in endothelial function, a predictor of adverse CV disease.

IMPACT

Vascular function changes in breast cancer cases on AIs compared to postmenopausal women. Further work is needed to evaluate vascular changes over time.

Acquired Tamoxifen Resistance in MCF-7 Breast Cancer Cells Requires Hyperactivation of eIF4F-Mediated Translation

While selective estrogen receptor modulators, such as tamoxifen, have contributed to increased survival in patients with hormone receptor-positive breast cancer, the development of resistance to these therapies has led to the need to investigate other targetable pathways involved in oncogenic signaling. Approval of the mTOR inhibitor everolimus in the therapy of secondary endocrine resistance demonstrates the validity of this approach. Importantly, mTOR activation regulates eukaryotic messenger RNA translation. Eukaryotic translation initiation factor 4E (eIF4E), a component of the cap-dependent translation complex eIF4F, confers resistance to drug-induced apoptosis when overexpressed in multiple cell types. The eIF4F complex is downstream of multiple oncogenic pathways, including mTOR, making it an appealing drug target. Here, we show that the eIF4F translation pathway was hyperactive in tamoxifen-resistant (TamR) MCF-7L breast cancer cells. While overexpression of eIF4E was not sufficient to confer resistance to tamoxifen in MCF-7L cells, its function was necessary to maintain resistance in TamR cells. Targeting the eIF4E subunit of the eIF4F complex through its degradation using an antisense oligonucleotide (ASO) or via sequestration using a mutant 4E-BP1 inhibited the proliferation and colony formation of TamR cells and partially restored sensitivity to tamoxifen. Further, the use of these agents also resulted in cell cycle arrest and induction of apoptosis in TamR cells. Finally, the use of a pharmacologic agent which inhibited the eIF4E-eIF4G interaction also decreased the proliferation and anchorage-dependent colony formation in TamR cells. These results highlight the eIF4F complex as a promising target for patients with acquired resistance to tamoxifen and, potentially, other endocrine therapies.

Relative effectiveness of adjuvant chemotherapy for invasive lobular compared with invasive ductal carcinoma of the breast

BACKGROUND

Invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC) have distinct clinical, pathologic, and genomic characteristics. The objective of the current study was to compare the relative impact of adjuvant chemotherapy on the survival of patients with ILC versus those with IDC.

METHODS

Women with estrogen receptor (ER)-positive, human epidermal growth factor receptor 1 (HER2) -negative, stage I/II IDC and ILC who received endocrine therapy were identified from the 2000 to 2014 California Cancer Registry. Patient, tumor, and treatment characteristics were collected. Ten-year overall survival (OS) was estimated using the Kaplan-Meier method and Cox proportional-hazards modeling.

RESULTS

In total, 32,997 women with IDC and 4638 with ILC were identified. The receipt of chemotherapy significantly decreased during the study for both subtypes. For patients with IDC, the 10-year OS rate was 95% among those who received endocrine therapy alone versus 93% (P < .01) among those who received endocrine therapy plus chemotherapy. For patients with ILC, the 10-year OS rate was 94% among those who received endocrine therapy alone versus 92% (P < .01) among those who received endocrine therapy plus chemotherapy. After adjusting for patient and treatment factors, adjuvant chemotherapy was significantly associated with a decreased 10-year hazard of death for patients with IDC (hazard ratio, 0.83; 95% confidence interval, 0.74-0.92). In contrast, adjuvant chemotherapy was not independently associated with the adjusted 10-year hazard of death for patients with ILC (hazard ratio, 1.14; 95% confidence interval, 0.90-1.46).

CONCLUSIONS

Adjuvant chemotherapy was not associated with improved OS for patients with ER-positive, HER2-negative, stage I/II ILC. Avoidance of ineffective chemotherapy will markedly reduce the adverse effects and economic burden of breast cancer treatment for a large proportion of patients with breast cancer. Cancer 2017;123:3015-21. © 2017 American Cancer Society.

Abstract S5-07: Aromatase inhibitors and endothelial function: Is there an association with early cardiovascular disease?

Background: As more women are cured from their breast cancer, survivors with early stage breast cancer are at greater risk of dying from cardiovascular disease than their breast cancer. Aromatase inhibitors (AI) have been shown to reduce breast cancer-related mortality in women with estrogen receptor (ER)-positive disease which makes up 75% of all breast cancer cases. The use of AIs has been associated with higher rates of hypertension, hypercholesterolemia, angina pectoris and ischemic cardiovascular disease. In the aging population taking AIs, little is known about the direct impact of AIs on endothelial function, a predictor of cardiovascular disease. Endothelial dysfunction identified by reactive hyperemia using Endo-PAT has been associated with an increased risk of cardiac adverse events, independent of Framingham risk score.

Methods: At the University of Minnesota in 2014-2015, 25 healthy postmenopausal women and 36 postmenopausal women with locally advanced breast cancer and prescribed an aromatase inhibitor were identified. Subjects with a history of hypertension or hyperlipidemia were excluded. Consented subjects underwent biomarker analysis and pulse wave analysis using the HDI/Pulse Wave CR-2000 Cardiovascular Profiling System and pulse contour analysis using the Endo-PAT2000 system. Biomarkers and functional test markers were compared between cases and controls using T-tests and Wilcoxon Rank-Sum tests.

Results: Mean age (61.7 vs 58.8 years), body mass index (27.4 vs 26.2 kg/m2), race (93% vs 92% Caucasian), and tobacco use (100% nonsmokers) were similar between cases and controls, respectively. Mean systolic blood pressure (BP) was elevated in cases (128.3 mmHg vs 114.5 mmHg, p=0.0006). There were no differences in lipid profiles. Median ultrasensitive estradiol levels were reduced in cases (2 vs 15 pg/mL, p&lt;0.0001). Median high sensitive C-reactive protein was significantly elevated in cases (4146 vs 1406 ng/L, p=0.05). There were no differences seen in markers of hemostasis or endothelial damage, including circulating endothelial cells, vascular cell adhesion molecule, P-selectin. Median large artery elasticity (12.5 vs 15.1 ml/mmHg, p=0.02), small artery elasticity (5.2 vs 6.7 ml/mmHg, p=0.04), and endoPAT ratio (0.8 vs 2.6, p&lt;0.0001) were significantly reduced in breast cancer survivors on AIs as compared to controls. There was no correlation between use of chemotherapy, radiation therapy, type of AI, or duration of AI use and endothelial function among the cases. When adjusting for differences in BP, endoPAT ratio continued to remain significantly decreased in breast cancer survivors (0.8 vs 2.6, p&lt;0.0001).

Conclusion: Postmenopausal women with breast cancer on AIs have reductions in endothelial function, a predictor of adverse cardiovascular disease (acute coronary syndrome, chest pain, myocardial infarction, cardiac death). With the growing trend that longer duration of endocrine therapy is needed, further work is needed to confirm these findings.

Citation Format: Blaes AH, Beckwith H, Hebbel R, Solovey A, Potter D, Yee D, Vogel R, Luepker R, Duprez D. Aromatase inhibitors and endothelial function: Is there an association with early cardiovascular disease? [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr S5-07.

Minireview: Were the IGF Signaling Inhibitors All Bad?

Preclinical studies in the 1980s defined a role for IGF signaling in the development and sustainability of the malignant process. Subsequently, antibody, tyrosine kinase, and ligand inhibitors of the IGF receptor were manufactured. In the past decade, numerous clinical trials have tested the efficacy of IGF receptor inhibitors in the treatment of advanced tumors. Early-phase trials in heavily pretreated populations showed promise with complete or partial responses in a few patients and stable disease in many more. Unfortunately, the results of the early-phase trials did not pan out to later-phase trials. The lack of use of biomarkers to define subsets of patients that may benefit from IGF receptor blockade and compensatory signaling via other growth factor receptors such as the insulin, GH, and epidermal growth factor receptors may have played a role in the lack of efficacy of IGF receptor inhibition in phase III trials. Although these trials failed to show benefit, the trials have revealed previously unknown knowledge regarding the complex nature of IGF signaling. The knowledge obtained from these trials will be useful in designing future trials studying inhibitors of growth factor signaling.

Angiotensin Converting Enzyme Inhibitors (ACEI) and doxorubicin pharmacokinetics in women receiving adjuvant breast cancer treatment

Purpose

Doxorubicin (DOX) chemotherapy can cause cardiac complications. Angiotensin converting enzyme inhibitors (ACEI) may protect against these complications. We performed a pharmacokinetics (PK) study to determine whether DOX levels are altered in the presence of ACEI.

Methods

In this randomized, cross-over, single-blinded drug-drug interaction study, 19 women with breast cancer prescribed DOX and cyclophosphamide every 14 days received one cycle of DOX chemotherapy with ACEI enalapril 10 mg daily and another cycle of DOX with placebo. Blood samples for DOX and doxorubicinol were drawn at baseline, 0.5, 1.0, 2.0, 4.0, 24.0 and 48.0 hours after infusion with and without ACEI enalapril. Correlative laboratories were also obtained. PK data was analyzed using non compartmental methods and DOX and doxorubicinol area under the curve (AUC) 0 to infinity, Cmax and half-life were estimated. Paired t-tests were used to determine whether DOX and its metabolite were altered with the use of enalapril (P < 0.05).

Results

17 women (median age 45 years) received 60 mg/m2 DOX every two weeks for four cycles. Mean (SD) AUC0- ∞ for DOX and doxorubicinol with enalapril exposure was 1185.56 (44.64) hr*ng/ml and 1040 (80.6) hr*ng/ml, respectively. AUC0- ∞ for DOX and doxobubicinol without enalapril was 1167.73 (45.26) hr*ng/ml and 1056.32 (92.03) hr*ng/ml, respectively. There is no interaction between DOX and enalapril. Enalapril was tolerated (33% grade 1 dizziness).

Conclusion

ACEI, enalapril, does not appear to alter the PK of DOX. Ongoing efforts to determine the effectiveness of ACEI as a cardioprotective agent in women receiving DOX chemotherapy should be continued.

Insulin-like growth factors, insulin, and growth hormone signaling in breast cancer: implications for targeted therapy

OBJECTIVE

In recent decades, multiple therapeutics targeting the estrogen and human epidermal growth factor-2 (HER2) receptors have been approved for the treatment of breast cancer.

METHODS

This review discusses a number of growth factor pathways that have been implicated in resistance to both anti-estrogen and HER2-targeted therapies. The association between growth factors and breast cancer is well established. Over decades, numerous laboratories have studied the link between insulin-like growth factor (IGF), insulin, and growth hormone (GH) to the development and progression of breast cancer.

RESULTS

Although preclinical data demonstrates that blockade of these receptors inhibits breast cancer growth, progression, and drug resistance, therapies targeting the IGF, insulin, and GH receptors (GHRs) have not been successful in producing significant increases in progression-free, disease-free, or overall survival for patients with breast cancer. The failure to demonstrate a benefit of growth factor blockade in clinical trials can be attributed to redundancy in IGF, insulin, and GHR signaling pathways. All 3 receptors are able to activate oncogenic phosphoinositide-3 kinase (PI3K) and mitogen-activated protein kinase (MAPK) pathways.

CONCLUSION

Consequently, multitargeted blockade of growth factor receptors and their common downstream kinases will be necessary for the successful treatment of breast cancer.

Abstract IA17: Targeting downstream effectors of growth factor signaling

Transmembrane growth factor receptors mediate signaling through multiple intracellular pathways. In breast cancer cells, the type I insulin-like growth factor receptor (IGF1R) has been implicated in the malignant phenotype. However, clinical trials with anti-IGF1R antibodies have been disappointing, in part, due to adaptive feedback pathways stimulated when IGF1R is blocked. To determine whether IGF1R inhibition could be enhanced by disrupting other pathways, we evaluated gene expression induced by receptor activation. In previous work, we found that xCT (SLC7A11) mRNA expression was increased by IGF-I in estrogen receptor (ER) positive breast cancer cell lines (MCF-7, T47D, and ZR-75-1) in an insulin receptor substrate-1 (IRS-1) dependent manner. xCT encodes the functional subunit of the heterodimeric plasma membrane transport system xC- critical for the cellular uptake of cystine to generate glutathione to modulate cellular redox control. IGF-I increased xC- transporter expression and function to control cellular redox levels. In MCF-7 cells, IGF-I-stimulated monolayer and anchorage-independent growth was suppressed by infecting cells with xCT shRNA or by treating cells with the xC- chemical inhibitor sulfasalazine (SASP). Anchorage-independent growth assays showed that disruption of xC- function by SASP sensitized cellular response of MCF-7 cells to anti-IGF-IR inhibitors (monoclonal antibody huEM164 and tyrosine kinase inhibitor NVP-AEW-541).

IGF1R also activates PI3K/Akt/mTORC1 signaling to affect ER phosphorylation and mRNA cap dependent translation. In tamoxifen resistant cells, IGF1R is lost yet PI3K signaling is maintained. Since mRNA cap dependent translation is increased by PI3K signaling, we determined if inhibition of the eIF4F translation pathway would affect endocrine responsive and tamoxifen resistant cells. The eIF4F translation pathway is activated by IGF1R in wild-type cells and hyperactive in tamoxifen resistant MCF-7L (TamR) breast cancer cells. Targeting the eIF4E subunit of the eIF4F complex through its degradation using an antisense oligonucleotide (ASO) or via sequestration using a mutant 4E-BP1 inhibited the proliferation and colony formation of parental and TamR cells. Use of these agents also resulted in cell cycle arrest and induction of apoptosis in TamR cells. Finally, pharmacologic inhibition of the eIF4E-eIF4G interaction also decreased the proliferation and anchorage dependent colony formation in TamR cells.

Taken together, these data show that IGF1R activation stimulates multiple downstream effectors important for breast cancer cell biology. Inhibition of selected downstream signaling molecules is likely to have synergy with anti-IGF-IR drugs.

Citation Format: Yuzhe Yang, Dedra Fagan, Lynsey Fettig Anderson, Kelly LaPara, Xihong Zhang, Aleksandra Ochnik, Jie Ying Chan, Heather Beckwith, Douglas Yee. Targeting downstream effectors of growth factor signaling. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research: Genetics, Biology, and Clinical Applications; Oct 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2013;11(10 Suppl):Abstract nr IA17.

Abstract P4-07-03: Rapamycin and Dalotuzumab in combination inhibit parental and endocrine resistant breast cancer cells

The PI3K/Akt/mTOR pathway is involved in breast cancer resistance to endocrine therapy. Inhibitors of mTOR have been shown to have benefit for patients with ER positive tumors that have developed endocrine therapy resistance. Inhibition of mTOR triggers a negative feedback loop resulting in enhanced phosphorylation of Akt and subsequent breast cancer cell proliferation via the IGF signaling pathway. Therefore, blockade of both IGF-1R and mTOR may be necessary to completely suppress this pathway. Our laboratory studied the effect of dual inhibition of mTOR and IGF-1R with rapamycin and dalotuzumab respectively on parental and endocrine resistant MCF-7 breast cancer cell tumorigenesis.

Immunoblotting demonstrates parental MCF-7L cells treated with rapamycin alone demonstrate increased phosphorylation of Akt. Inhibition of phosphorylation of Akt can be achieved with combined treatment with rapamycin and dalotuzumab at concentrations of 5 nM and 2 µg/mL respectively. In addition to inhibition of pAkt, combined treatment inhibits phosphorylation of S6K1 and the translational repressor protein, 4eBP1. Furthermore, MTT proliferation assay and soft agar assay demonstrate inhibition of parental cell proliferation and colonization respectively with combined rapamycin and dalotuzumab treatment. In order to examine the effect of combination therapy in endocrine resistant cell lines, we established tamoxifen resistant (TamR) and long term estrogen deprived (LTED) cell lines. TamR cells were generated by culturing MCF-7L cells in the presence of tamoxifen for more than 1 year. LTED cells were generated by culturing MCF-7L cells in the absence of estrogen for more than 6 months. Proliferation of TamR and LTED cells treated with rapamycin at a concentration of 5nM and dalotuzumab at a concentration of 2µg/mL in combination was significantly inhibited. We conclude that combination of IGF1R and mTOR inhibition might be necessary to inhibit endocrine resistant breast cancers. Ongoing clinical trials will test this combination of drugs.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-07-03.