Hypertensive events after the initiation of contemporary cancer therapies for breast cancer control

BACKGROUND

Contemporary therapies improve breast cancer (BC) outcomes. Yet, many of these therapies have been increasingly linked with serious cardiotoxicity, including reports of profound hypertension. Yet, the incidence, predictors, and impacts of these events are largely unknown.

METHODS

Leveraging two large U.S.-based registries, the National Inpatient Sample (NIS) and the Food and Drug Administration Adverse Event Reporting System (FAERS) databases, we assessed the incidence, factors, and outcomes of hypertensive events among BC patients from 2007 to 2015. Differences in baseline characteristics, hypertension-related discharges, and complications were examined over time. Further, we performed a disproportionality analysis using reporting-odds-ratios (ROR) to determine the association between individual BC drugs and hypertensive events. Utilizing an ROR cutoff of >1.0, we quantified associations by drug-class, and individual drugs with the likelihood of excess hypertension.

RESULTS

Overall, there were 5,464,401 BC-admissions, of which 46,989 (0.8%) presented with hypertension. Hypertensive BC patients were older, and saw initially increased in-hospital mortality, which equilibrated over time. The mean incidence of hypertension-related admissions was 732 per 100,000 among BC patients, versus 96 per 100,000 among non-cancer patients (RR 7.71, p < 0.001). Moreover, in FAERS, those with hypertension versus other BC-treatment side-effects were more frequently hospitalized (40.1% vs. 36.7%, p < 0.001), and were most commonly associated with chemotherapy (45.9%). Outside of Eribulin (ROR 3.36; 95% CI 1.37-8.22), no specific drug was associated with a higher reporting of hypertension; however, collectively BC drugs were associated with a higher odds of hypertension (ROR 1.66; 95% CI 1.09-2.53).

CONCLUSIONS

BC therapies are associated with a substantial increase in limiting hypertension.

Aromatase-Inhibitor-Induced Musculoskeletal Inflammation Is Observed Independent of Oophorectomy in a Novel Mouse Model

Aromatase Inhibitors (AIs) block estrogen production and improve survival in patients with hormone-receptor-positive breast cancer. However, half of patients develop aromatase-inhibitor-induced arthralgia (AIIA), which is characterized by inflammation of the joints and the surrounding musculoskeletal tissue. To create a platform for future interventional strategies, our objective was to characterize a novel animal model of AIIA. Female BALB/C-Tg(NFκB-RE-luc)-Xen mice, which have a firefly luciferase NFκB reporter gene, were oophorectomized and treated with an AI (letrozole). Bioluminescent imaging showed significantly enhanced NFκB activation with AI treatment in the hind limbs. Moreover, an analysis of the knee joints and legs via MRI showed enhanced signal detection in the joint space and the surrounding tissue. Surprisingly, the responses observed with AI treatment were independent of oophorectomy, indicating that inflammation is not mediated by physiological estrogen levels. Histopathological and pro-inflammatory cytokine analyses further demonstrated the same trend, as tenosynovitis and musculoskeletal infiltrates were detected in all mice receiving AI, and serum cytokines were significantly upregulated. Human PBMCs treated with letrozole/estrogen combinations did not demonstrate an AI-specific gene expression pattern, suggesting AIIA-mediated pathogenesis through other cell types. Collectively, these data identify an AI-induced stimulation of disease pathology and suggest that AIIA pathogenesis may not be mediated by estrogen deficiency, as previously hypothesized.

Living with Advanced Breast Cancer: A Descriptive Analysis of Survivorship Strategies

Survivors of advanced breast cancer (ABC), also known as metavivors, are often left with fewer treatment options in the landscape of a cure culture. Metavivors have unique psychosocial and physical needs distinct from patients with early-stage breast cancer. This analysis delves into side effects commonly experienced by patients with ABC, such as fatigue, anxiety, and cardiotoxicity; how these side effects impact caregiver support, financial toxicity, emotional strain, and spiritual and emotional distress; as well as current strategies for mitigation, including nutrition, exercise, and participation in clinical research. Overall, this analysis is a mandate for additional research to explore novel treatments and implement strategies to maintain and improve patients’ quality of life.

Features, Outcomes, and Management Strategies of Male Breast Cancer: A Single Institution Comparison to Well-Matched Female Controls

Objective

The primary objective of this study was to delineate differences in management, overall and distant disease-free survival in males diagnosed with breast cancer and treated at The Ohio State University Comprehensive Cancer Center as compared to comprehensively matched female subjects. Secondary objectives included assessment of clinical and histopathologic features and recurrence score, as measured by Oncotype DX and the modified Magee equation #2.

Materials and Methods

This single institution retrospective study compared male and comprehensively matched female patients (1:2) with stage I-III breast cancer between 1994 and 2014. Recurrence risk was estimated using a modified Magee equation. Overall survival and distant disease-free survival were estimated and compared using Kaplan-Meier and Log-rank methods.

Results

Forty-five male breast cancer patients were included (stage I: 26.7%; stage II: 53.3%; stage III: 20.0%; hormone receptor positive: 97.8%; human epidermal growth factor receptor 2 negative: 84.4%) with a median age of 63.8 (43.0-79.4) years at diagnosis. Intermediate and low recurrence scores were most common in male and female patients respectively; mean score was similar between groups (20.3 vs. 19.8). The proportion of male breast cancer patients treated with adjuvant chemotherapy and post-mastectomy radiation was lower compared to female patients (42.2% vs. 65.3%, p=0.013; 22.7% vs. 44.4%, p=0.030, respectively). Overall survival and distant disease-free survival between male and female patients were similar.

Conclusion

Male breast cancer patient outcomes were similar compared to well-matched female patients suggesting that breast cancer specific factors are more prognostic than gender.

Metastatic breast cancer patient perceptions of somatic tumor genomic testing

BACKGROUND

To assess metastatic breast cancer (MBC) patient psychological factors, perceptions, and comprehension of tumor genomic testing.

METHODS

In a prospective, single institution, single-arm trial, patients with MBC underwent next-generation sequencing at study entry with sequencing results released at progression. Patients who completed surveys before undergoing sequencing were included in the present secondary analysis (n = 58). We administered four validated psychosocial measures: Center for Epidemiologic Studies Depression Scale, Beck Anxiety Inventory, Trust in Physician Scale, and Communication and Attitudinal Self-Efficacy scale for Cancer. Genetic comprehension was assessed using 7-question objective and 6-question subjective measures. Longitudinal data were assessed (n = 40) using paired Wilcoxon signed rank and McNemar's test of agreement.

RESULTS

There were no significant differences between the beginning and end of study in depression, anxiety, physician trust, or self-efficacy (median time on study: 7.6 months). Depression and anxiety were positively associated with each other and both negatively associated with self-efficacy. Self-efficacy decreased from pre- to post-genomic testing (p = 0.05). Objective genetics comprehension did not significantly change from pre- to post-genomic testing, but patients expressed increased confidence in their ability to teach others about genetics (p = 0.04). Objective comprehension was significantly lower in non-white patients (p = 0.02) and patients with lower income (p = 0.04).

CONCLUSIONS

This is the only study, to our knowledge, to longitudinally evaluate multiple psychological metrics in MBC as patients undergo tumor genomic testing. Overall, psychological dimensions remained stable over the duration of tumor genomic testing. Among patients with MBC, depression and anxiety metrics were negatively correlated with patient self-efficacy. Patients undergoing somatic genomic testing had limited genomic knowledge, which varied by demographic groups and may warrant additional educational intervention.

CLINICAL TRIAL INFORMATION

NCT01987726, registered November 13, 2013.

A phase I study of an oral selective gamma secretase (GS) inhibitor RO4929097 in combination with neoadjuvant paclitaxel and carboplatin in triple negative breast cancer

Upregulation of Notch pathway is associated with poor prognosis in breast cancer. We present the results of a phase I study of an oral selective gamma secretase (GS) inhibitor (critical to Notch signaling), RO4929097 in combination with neoadjuvant chemotherapy for operable triple negative breast cancer. The primary objective was to determine the maximum tolerated dose (MTD) of RO4929097. Secondary objectives were to determine real-time pharmacokinetics of RO4929097 and paclitaxel, safety and pathologic (pCR) complete response to study treatment. Eligible patients, initiated carboplatin at AUC 6 administered intravenously (IV) on day 1, weekly paclitaxel at 80 mg/m2 IV and RO4929097 10 mg daily given orally (PO) on days 1-3, 8-10 and 15-17 for six 21-day cycles. RO4929097 was escalated in 10 mg increments using the 3 + 3 dose escalation design. Two DLTs were observed in 14 patients - Grade (G) 4 thrombocytopenia in dose level 1 (10 mg) and G3 hypertension in dose level 2 (20 mg). Protocol-defined MTD was not determined due to discontinuation of RO4929097 development. However, 4 of 5 patients enrolled to 20 mg dose of RO4929097 required dose reduction to 10 mg due to toxicities (including neutropenia, thrombocytopenia and hypertension) occurring during and beyond the DLT observation period. Thus, 10 mg would have been the likely dose level for further development. G3 or higher hematologic toxicities included neutropenia (N = 8, 57%) and thrombocytopenia (N = 5, 36%) patients. Six (43%) patients had G2-3 neuropathy requiring paclitaxel dose reduction. No signs of drug-drug interaction between paclitaxel and RO4929097 were evident. Five patients (36%) had pCR.

Assessment of outcomes and novel immune biomarkers in metaplastic breast cancer: a single institution retrospective study

BACKGROUND

Metaplastic breast cancer remains poorly characterized given its rarity and heterogeneity. The majority of metaplastic breast cancers demonstrate a phenotype of triple-negative breast cancer; however, differences in clinical outcomes between metaplastic breast cancer and triple-negative breast cancer in the era of third-generation chemotherapy remain unclear.

METHODS

We compared the clinical outcomes between women with metaplastic breast cancer and women with triple-negative breast cancer diagnosed between 1994 and 2014. Metaplastic breast cancer patients were matched 1:3 to triple-negative breast cancer patients by stage and age at diagnosis. Distant disease-free survival (DDFS) and overall survival (OS) were estimated using Kaplan Meier methods and Cox proportional hazard regression models. Immune checkpoint markers were characterized by immunohistochemistry in a subset of samples.

RESULTS

Forty-four metaplastic breast cancer patients (stage I 14%; stage II 73%; stage III 11%; stage IV 2%) with an average age of 55.4 (± 13.9) years at diagnosis. Median follow-up for the included metaplastic breast cancer and triple-negative breast cancer patients (n = 174) was 2.8 (0.1-19.0) years. The DDFS and OS between matched metaplastic breast cancer and triple-negative breast cancer patients were similar, even when adjusting for clinical covariates (DDFS: HR = 1.64, p = 0.22; OS: HR = 1.64, p = 0.26). Metaplastic breast cancer samples (n = 27) demonstrated greater amount of CD163 in the stroma (p = 0.05) and PD-L1 in the tumor (p = 0.01) than triple-negative breast cancer samples (n = 119), although more triple-negative breast cancer samples were positive for CD8 in the tumor than metaplastic breast cancer samples (p = 0.02).

CONCLUSIONS

Patients with metaplastic breast cancer had similar outcomes to those with triple-negative breast cancer based on DDFS and OS. The immune checkpoint marker profile of metaplastic breast cancers in this study may prove useful in future studies attempting to demonstrate an association between immune profile and survival.

Spider Telangiectases and Palmar Erythema as Harbingers of Structural Liver Changes in Three Breast Cancer Patients on Ado-trastuzumab Emtansine

Objective: We describe three patients treated with ado-trastuzumab emtansine who developed either palmar flushing or spider angiomas. We then correlate these findings with radiologic imaging results of the liver. Design: Three consecutive referrals to dermatology for patient skin complaints while taking ado-trastuzumab emtansine were evaluated and found to have either telangiectases or palmar flushing. Two patients who did not have prominent nodularity on computed tomography of the liver underwent transient elastography. Results: All three patients with stigmata of liver disease that developed during the course of ado-trastuzumab emtansine demonstrated parenchymal liver abnormalities. Conclusion: Patients presenting with spider angiomas and/or palmar flushing on adotrastuzumab emtansine should be considered for elastography studies to ensure early structural damage is not occurring. Further investigation is needed to define the precise etiology for these telangiectases and the role of elastography imaging in monitoring patients on long-term adotrastuzumab emtansine.

Pathological complete response rates with pertuzumab-based neoadjuvant chemotherapy in breast cancer: A single-center experience

BACKGROUND

Pertuzumab-based neoadjuvant chemotherapy (NAC) has demonstrated successful pathologic complete response (pCR) rates when administered to patients with human epidermal growth factor receptor 2 (HER2)-positive, locally advanced breast cancer and has become standard of care. This study aimed to identify pCR rates in patients receiving a variety of pertuzumab-based NAC regimens. The effect of the addition of an anthracycline and impact of anthracycline and taxane sequencing on pCR was also assessed.

METHODS

A retrospective, single-center review was conducted on patients with operable, human epidermal growth factor receptor 2 (HER2)-positive breast cancer that received one of five pertuzumab-containing NAC regimens followed by definitive surgery.

RESULTS

Ninety-six patients were included in the analysis; overall, pCR was attained in 49 patients (51%). Of the 61 patients who received an anthracycline-containing NAC regimen, 30 (49%) attained a pCR. Of the 35 patients who received the non-anthracycline NAC regimen, 19 (54%) attained a pCR; difference in pCR was not statistically significant (p = 0.63). Anthracycline/taxane sequence analysis showed that of the patients attaining pCR with an anthracycline-containing NAC, 77% of patients received the taxane portion upfront (p = 0.17). Relative dose intensity of the anthracycline portion was similar irrespective of treatment sequence. However, relative dose intensity of the taxane portion was decreased with upfront anthracycline administration.

CONCLUSION

These findings support current recommendations of adding pertuzumab to established regimens for treatment of locally advanced, HER2-positive, early stage breast cancer. The benefit of adding an anthracycline in the neoadjuvant setting remains unclear. Patients treated with the taxane portion of NAC upfront appeared to have a higher rate of pCR and better relative dose intensity than patients who received the anthracycline portion upfront, but differences were not statistically significant. These findings should be verified in a prospective clinical trial.

Abstract P3-07-08: Multi-omic predictor of rapid and late relapse in primary triple negative breast cancer

Background: Triple-negative breast cancer (TNBC) is a heterogeneous disease. Clinically, we observe three distinct TNBC outcomes: 1) rapid relapse (rrTNBC) characterized by aggressive drug resistant disease; 2) late relapse (lrTNBC) characterized by indolent or treatment responsive disease; and 3) no relapse (NoRTNBC). We hypothesized that distinct clinical and genomic features of primary tumors define rapid versus late relapse in TNBC.

Approach: Using three publicly-available datasets (METABRIC, TCGA, and a prior gene expression meta-analysis), we identified 455 patients diagnosed with primary TNBC with adequate follow-up to be characterized as rrTNBC (relapse or death within 2 years of diagnosis), lrTNBC (relapse or death more than 2 years after diagnosis), or NoRTNBC (no relapse/death with at least 5 years follow-up). We compiled basic clinical (n=455 patients) and primary tumor multi-omic data, including whole transcriptome (n=455), whole genome copy number (n=317), and mutation data for 171 cancer-related genes (n=317). We evaluated intrinsic subtypes (PAM50, TNBCtype), 125 gene expression signatures, CIBERSORT immune subsets, copy number, and mutation frequency.

Results: We first evaluated patients with relapse (rrTNBC+lrTNBC) vs. NoRTNBC. There was no significant difference in age, grade, stage at diagnosis, or PAM50 or TNBC subtype proportion between relapse and NoRTNBC. Among 125 expression signatures, five immune signatures were significantly higher in NoRTNBCs (FDR p&lt;0.05) suggesting increased immune activity in patients who do not relapse. Using CIBERSORT inferred immune subsets, anti-tumor CD8 T-cell, M1 macrophage, and gamma-delta T-cell subsets were all highly correlated to these immune signatures (all Pearson's r &gt;= 0.3, all p&lt;1.2e-8). Among genomic features, patients who relapsed were significantly more likely to harbor a mutation in PIK3CA (Fisher exact FDR p=0.02) but there was no significant difference in tumor mutation burden or percent genome altered (Student's t-test p=0.83 and p=0.99, respectively). We then evaluated primary TNBC genomic data in patients who ultimately developed rapid vs. late relapse. Patients with rrTNBC were more likely to be higher stage (p&lt;0.0001) while lrTNBC were more likely to be non-basal PAM50 subtype (p=0.03). Among 11 significantly altered gene expression signatures (FDR p&lt;0.05), 6 estrogen/luminal signatures were significantly higher in lrTNBC. Mutations in DNAH11 and PIK3CA were more common in lrTNBC (Fisher exact FDR p=0.04 and p=0.05, respectively) but there were no significant differences in tumor mutation burden or copy number burden (Student's t-test p=0.13 and p=0.45, respectively). Using 317 cases with full genomic data divided into training and validation datasets, we will report a comparison of machine learning models for predicting relapse versus no relapse and rapid versus late relapse.

Conclusions: Primary TNBC tumors destined for rapid, late, or no relapse reflect distinct genomic features. Anti-tumor immune signatures and subsets are enriched in patients who do not relapse yet no difference in mutational or copy number burden. Relative to rapid relapse TNBCs, late relapse TNBCs are enriched for non-basal tumors, estrogen/luminal expression signatures, and mutations in DNAH11 and PIK3CA.

Citation Format: Zhang Y, Nock W, Asad S, Adams E, Singh J, Damicis A, Lustberg MB, Noonan A, Reinbolt R, Sardesai S, VanDeusen J, Wesolowski R, Williams N, Ramaswamy B, Stover DG. Multi-omic predictor of rapid and late relapse in primary triple negative breast cancer [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 P3-07-08.

Abstract P1-09-01: CD8+ T-cell gene expression and signatures in breast cancer and adjacent normal breast tissue: Association with body mass index, alcohol intake, and age at diagnosis

Background: Our understanding of mediators of immune infiltration in breast cancer and normal breast tissue remains limited. We hypothesize that patient factors known to be associated with inflammation and immune subsets, including body mass index, alcohol intake, and age and diagnosis, may play an important role in the tumor-immune microenvironment. Analyses of immune gene expression and signatures facilitate interrogation of the immune microenvironment in large patient cohorts.

Methods: Participants from the Nurses' Health Study cohorts I and II diagnosed with invasive breast cancer were included. Total RNA extracted and microarray performed for 882 tumor and 695 tumor-adjacent samples, of which 623 tumors have matched tumor-adjacent data. CD8+ T-cell expression metrics were assessed: CD8A single gene expression (CD8Agene), a CD8 T-cell signature (CD8sig), and a tumor infiltrating lymphocyte signature derived from the GeparSixto clinical trial (GSAct). Standard clinicopathologic features were evaluated, as well as body mass index (BMI) one year prior to diagnosis, cumulative average alcohol intake, and age at diagnosis.

Results: Overall, tumor and adjacent normal tissue demonstrated positive correlation of CD8Agene, CD8sig, and GSAct (n=623 pairs, Pearson's r = 0.46, 0.36, 0.31, respectively; all p&lt;0.001). Similar correlations were present in TCGA breast cancer, an independent cohort (n=112 pairs, Pearson's r = 0.34, 0.17, 0.45, respectively; all p&lt;0.001). We evaluated paired tumor and adjacent normal samples within individual immunohistochemical (IHC) subtype or PAM50 subtype by Wilcoxon signed-rank test. There was not a consistent trend for CD8Agene, CD8sig, nor GSAct to be greater in tumor or normal within subtypes. We then evaluated patient features/exposures and tumor immune expression metrics. For tumor-adjacent normal, there was no significant association of alcohol intake, BMI, or age at diagnosis with CD8 gene/expression metrics. For tumor tissue, a multivariate model demonstrated that BMI one year before diagnosis was significantly associated with CD8Agene expression. There was no significant association of alcohol intake or age at diagnosis with CD8 gene/expression metrics. We are currently evaluating the association of these CD8 T-cell gene expression signatures with CD8 T-cell immunohistochemistry in a subset of patients, which will be reported at the time of abstract presentation.

Conclusion: In this cohort of over 600 tumor:normal pairs and a separate validation cohort, multiple distinct CD8+ T-cell expression metrics are correlated between breast cancer and tumor-adjacent normal breast tissue. This suggests that the adjacent normal breast may reflect an altered immune microenvironment in the context of breast cancer. While age at diagnosis and alcohol intake are not significantly associated with tumor CD8 expression metrics, BMI was significantly associated with tumor CD8Agene expression in a multivariate model.

Citation Format: Damicis A, Heng YJ, Kensler K, Asad S, Adams E, Singh J, Zhang Y, Nock W, Wesolowski R, Williams N, Reinbolt R, Sardesai S, VanDeusen J, Noonan A, Lustberg MB, Ramaswamy B, Eliassen AH, Hankinson SE, Tamimi R, Stover DG. CD8+ T-cell gene expression and signatures in breast cancer and adjacent normal breast tissue: Association with body mass index, alcohol intake, and age at diagnosis [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 P1-09-01.

Abstract P4-16-03: Cardiovascular outcomes and long term survival with discontinuation of adjuvant trastuzumab

Background: Trastuzumab (T) induced cardiomyopathy remains a significant limitation to adjuvant HER2 directed therapy. Recent studies have aimed to reduce cardiotoxicity through combination with non-anthracycline (non-A) chemotherapy or shorter treatment duration. However there is limited data regarding cardiac outcomes and long-term survival with early discontinuation of adjuvant T.

Methods: An IRB-approved single-institution retrospective analysis was performed for 401 consecutive patients with non-metastatic HER2+ breast cancer treated at the Ohio State University Comprehensive Cancer Center from 2005-2015. Medical records were reviewed for clinicopathologic features, systemic treatment and survival information. Disease Free Survival (DFS) was defined as time from diagnosis to first recurrence (loco-regional or distant recurrence) including second primary breast cancer or death. Overall survival (OS) was defined as time from diagnosis to death or last known follow up. OS and DFS estimates were generated using Kaplan Meier methods and compared using Log-rank tests. Cox proportional hazard models were used to calculate univariate and multivariate hazard ratios for OS and DFS.

Results: A total of 371/401 (92.5%) patients received adjuvant T (n= 401, mean age: 59.4 years; stage 1: 120, 30%; stage II: 194, 48%; stage III: 87, 22%; ER+: 235, 58%); among whom 106/371 (28.6%) patients held adjuvant T for any reason. Median duration of therapy in patients with any interruption with T was 11.3 (0.5-16.9) months and 23/371 (6.9%) received less than 6 months of adjuvant T. Cardiomyopathy (measured as LVEF decline on 2D echocardiogram or MUGA &gt;= 15 points) was the most common reason for withholding T (66/106, 62.3%). The majority of these patients received a cardiology referral (77/ 106, 72.6%) with a 13 day mean time to evaluation in outpatient clinic. Patients receiving non-A chemotherapy and beta blockers or ACE inhibitors during treatment were significantly less likely to experience cardiomyopathy (A vs non-A: 49/190, 25.8% vs. 16/136, 11.8% p=0.002); (Med vs no Med: 7/148, 4.73% vs 59/184, 32.1%; p&lt;0.001). Log-rank tests indicate a significant worsening in OS and DFS for patients who discontinued T (p=0.021, 0.001 respectively). Multivariate analyses confirmed significant worsening in DFS after adjusting for age, stage, ER , node status, and cardiomyopathy (Adjusted HR: 4.0[2.02 – 7.92], p&lt; 0.001)

Table 1- Discontinuation of adjuvant trastuzumab Number of patients (%)Initial treatment371Completed therapy with no interruption265 (71.4)Interruption of therapy for minimum of 2 weeks64 (17.2)Permanently discontinued42 (11.3)

Conclusion: Discontinuation of adjuvant trastuzumab, most often from cardiomyopathy, is an independent prognostic marker for worse DFS in non-metastatic HER2 positive breast cancer. Non-anthracycline chemotherapy and use of cardio-protective medication is associated with significantly reduced incidence of cardiotoxicity in this population. Future prospective studies should consider optimizing cardiovascular function to avoid interruption in adjuvant HER 2 directed therapy.

Citation Format: Sardesai S, Liu J, Palettas M, Stephens J, Stover D, Williams N, Reinbolt R, VanDeusen J, Wesolowski R, Lustberg M, Ramaswamy B. Cardiovascular outcomes and long term survival with discontinuation of adjuvant trastuzumab [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 P4-16-03.

An overview of the unique challenges facing African-American breast cancer survivors

PURPOSE

The existence of cancer disparities is well known. Focus on alleviating such disparities centers on diagnosis, treatment, and mortality. This review surveyed current knowledge of health disparities that exist in the acute survivorship period (immediately following diagnosis and treatment) and their contributors, particularly for African-American breast cancer survivors (AA-BCS).

METHODS

Utilizing the ASCO four components of survivorship care, we explore disparities in surveillance and effects of cancer and therapies that AA-BCS face within the acute survivorship period (the years immediately following diagnosis). A literature review of PUBMED, Scopus, and Cochrane databases was conducted to identify articles related to AA-BCS acute survivorship. The search yielded 97 articles. Of the 97 articles, 38 articles met inclusion criteria.

RESULTS

AA-BCS experience disparate survivorship care, which negatively impacts quality of life and health outcomes. Challenges exist in surveillance, interventions for late effects (e.g., quality-of-life outcomes, cardiotoxicity, and cognitive changes), preventing recurrence with promotion of healthy living, and coordinating care among the healthcare team.

CONCLUSIONS

This overview identified current knowledge on the challenges in survivorship among AA-BCS. Barriers to optimal survivorship care inhibit progress in eliminating breast cancer disparities. Research addressing best practices for survivorship care is needed for this population. Implementation of culturally tailored care may reduce breast cancer disparities among AA-BCS.

Abstract A20: Analysis of tumor infiltrating lymphocytes and expression of PD1 and PD-L1 in breast tumors prior to and after neoadjuvant chemotherapy

Introduction: The effect of chemotherapy on the presence of tumor-infiltrating lymphocytes (TILs) and expression of PD1 and PD-L1 is unclear. We sought to describe the differences in the percentage (%) of TILs, cytotoxic T lymphocytes (CTL), and expression of PD1/PD-L1 in tumors of patients (pts) with operable breast cancer (BC) treated with neoadjuvant chemotherapy (NAC) who were enrolled in a biomarker study at our institution (IRB protocol# 2010C0036).

Methods: A multicolor immune-histochemical multiplex assay simultaneously detecting PD1, PD-L1, and CD8 expressing cells was performed on formalin-fixed, paraffin-embedded diagnostic pretreatment biopsy or resected tumor specimen following NAC in 18 of 26 pts participating in the study. A cut-off of ≥1% was considered positive for PD1 and PD-L1 expression. We evaluated stromal and intratumoral CTLs by estimating % of stroma and tumor that contained CD8+ cells. In addition, stromal TILs (sTILs) were identified on full-face hematoxylin and eosin stained sections and defined as the % of tumor stroma containing infiltrating lymphocytes. Pathologic complete or near-complete response (pCR) was analyzed based on residual cancer burden (RCB) score and defined as RCB class 0 or I. Analysis of all slides was performed by an expert breast pathologist. Since the number of pts was limited, we only provide descriptive statistics (mean, range). In addition, because most pts had only a biopsy or only residual tumor available for the analysis, we divided pts into 2 separate cohorts based on what tissue was available.

Results: Of 18 pts, biopsy was analyzed in 7 (Bx cohort) and residual tumor was analyzed in 11 pts (RT cohort). The median age of study pts was 48 (range 32-70); 11 (61%), 6 (33%), and 1 (6%) of pts were Caucasian, African American, and Hispanic, respectively. Ten pts (5 in Bx and RT cohorts each) had triple-negative BC (TNBC), 4 had HER2+ BC (1 and 3 in Bx and RT cohorts, respectively), and 4 had hormone receptor-positive, HER2- BC (1 and 3 in Bx and RT cohorts, respectively). Eight pts (44%) had pCR. In the bx cohort, 85% of pts had pCR while 18% of pts in the RT cohort had minimal residual disease (RCB class I). In the Bx cohort, average % of sTILs was 30% (range 2-70%), including 1 pt (14%) with lymphocyte predominant tumor (≥50% of sTILs). The % of sTILs was similar in the 11 residual tumors (mean 22, range 2-60) with 2 pts having lymphocyte predominant tumors. Average % of CTLs was 19 (range 1-50) in the Bx cohort and 14 (range 1-50) in the RT cohort. An average % of intratumoral CTLs was 8 (range 1-30) and 7.5 (range 0-40) while the average % of stromal CTLs was 25 (range 1-60) and 19 (range 1-60) in the Bx and RT cohorts, respectively. Similar % and trends were seen in 10 TNBC pts. PD-L1 expression was seen in 86% and 36% of tumors in the Bx and RT cohorts, respectively, with majority of expression present in the stroma. All cases of intratumoral PD-L1 expression were also positive for stromal PD-L1 expression. This difference was also seen in the TNBC pts (80% vs. 40% of tumors were PD-L1+ in Bx and RT cohorts, respectively). An average PD-L1 intensity was approximately 3% in both cohorts (range 1-20%). Expression of PD1 was very low (1% intensity in 3 pts in Bx cohort and in 1 pt in RT cohort) and it was seen on CD8+ CTLs.

Conclusion: Our study preliminarily shows that percent of sTILs and stromal and intratumoral CTLs does not differ between pretreatment biopsy and residual tumors following NAC. Lower proportion of residual tumors were PD-L1+ compared to pretreatment biopsy specimen. The study limitations include small number of subjects and lack of comparison in the same pts. Future studies are needed to confirm these findings.

Citation Format: Robert Wesolowski, Zaibo Li, Christopher McQuinn, Maryam Lustberg, Bhuvaneswari Ramaswamy, Anne Noonan, Raquel Reinbolt, Sagar Sardesai, Jeffrey B. VanDeusen, Nicole Williams, William E. Carson, III. Analysis of tumor infiltrating lymphocytes and expression of PD1 and PD-L1 in breast tumors prior to and after neoadjuvant chemotherapy [abstract]. In: Proceedings of the AACR Special Conference: Advances in Breast Cancer Research; 2017 Oct 7-10; Hollywood, CA. Philadelphia (PA): AACR; Mol Cancer Res 2018;16(8_Suppl):Abstract nr A20.

Abstract A69: Efficacy of alternative 28-day capecitabine dosing schedule in metastatic breast cancer

Background: The approved dosing schedule of capecitabine monotherapy in metastatic breast cancer (MBC) is 1250 mg/m2/dose administered days 1 through 14 of a 21-day cycle, but many patients (pts) have difficulty with this schedule due to side effects. Use of a lower starting dose such as 1000 mg/m2/dose or use of an alternative 28-day administration schedule (7 day on, 7 day off, repeat) allows for greater tolerability. Given limited data regarding efficacy of the alternative 28-day schedule, the primary objective of this study was to compare the efficacy of different schedules of capecitabine in patients with MBC.

Methods: A retrospective chart review of pts with metastatic breast cancer who received capecitabine as monotherapy between 2002 and 2014 at the Ohio State University James Cancer Hospital was performed. We excluded any HER2-positive patients who had received concurrent HER2-targeted therapy. Pts who initiated therapy at a dose of 1000 mg/m2/dose were classified by these dosing schedules: Arm A (21 day), B (28 day), and C (changeover from 21 day to 28 day). Time to treatment failure (TTF) and overall survival (OS) were compared between dosing schedules using Kaplan Meier curves and log-rank tests.

Results: A total of 181 MBC patients (Arm A: n = 113, Arm B: n = 25, Arm C: n = 43) with the following patient characteristics met eligibility criteria; 86.2% Caucasians, 13.8% non-Caucasians, 64.64% estrogen receptor (ER)-positive, 3.31% ER positive/HER2-positive, 2.22% ER negative/HER2-positive, and 29.83% triple-negative. The HER2-positive patients were excluded as they received concurrent therapy. A significant difference was seen in TTF (Arm A: 2.7 mo, Arm B: 2.8 mo, Arm C: 7.1 mo, p = 0.001) when comparing all dosing schedules as well as in OS (Arm A: 5.7 yrs, Arm B: 9.6 yrs, Arm C: 7.8 yrs, p = 0.006). After an initial dose reduction, patients on Arm B tolerated capecitabine for a longer period of time than patients on Arm A before needing a second dose reduction (Table 1). The median time on capecitabine for Arm A was 11.9 weeks and 12.6 weeks for Arm B, and the mean time of both Arm A and Arm B on capecitabine was 22.2 weeks. Patients with ER-positive breast cancer had improved TTF (4.45 months vs 2.32 months, p &lt; 0.001) and OS (7.26 years vs 3.99 years, p &lt; 0.001) compared to ER-negative breast cancer. Caucasians had improved TTF compared to African Americans (AA) and other races (3.90 mo vs 2.87 mo, p = 0.004); however, there was no significant difference in OS.

Median starting dose (mg/m2): Arm A - 1000; Arm B - 1043; Arm C - 1000

Time to 1st dose reduction (weeks): Arm A - 6; Arm B - 6; Arm C - 6.5

Dose after 1st reduction (mg/m2): Arm A - 808; Arm B - 848.5; Arm C - 802

Time to 2nd dose reduction (weeks): Arm A - 6; Arm B - 20; Arm C - 8

Dose after 2nd reduction (mg/m2): Arm A - 599.5; Arm B - 690; Arm C - 697

Time to 3rd dose reduction (weeks): Arm A - 6; Arm B - 0; Arm C - 24

Dose after 3rd reduction (mg/m2): Arm A - 575; Arm B - 0; Arm C - 557

Table 1: Median dose (mg/m2) and median time to reductions (in weeks)

Conclusions: Our study shows that patients who received the 28-day cycle initially or who were switched to the 28-day cycle appeared to have improved TTF and OS compared to patients on the 21-day cycle. It also shows that AA women had worse TTF on capecitabine when compared to Caucasians. One hypothesis for the improved TTF and OS is that this could be due to a higher total dose of capecitabine received in Arm B and C as shown in Table 1. We acknowledge that the limitations of our study include the sample size and the retrospective nature, and that further work needs to be done. However, the 28-day dosing schedule for capecitabine could be an alternative for elderly patients or patients with poor performance status who are at higher risk for drug toxicities.

Citation Format: Nicole Olivia Williams, Anupama Suresh, Julie Stephens, Marilly Palettas, Michael J. Berger, Akaansha Ganju, Raquel Reinbolt, Robert Wesolowski, Anne M. Noonan, Jeffrey Bryan VanDeusen, Sagar Sardesai, Maryam Lustberg, Maryam B. Lustberg, Bhuvaneswari Ramaswamy. Efficacy of alternative 28-day capecitabine dosing schedule in metastatic breast cancer [abstract]. In: Proceedings of the AACR Special Conference: Advances in Breast Cancer Research; 2017 Oct 7-10; Hollywood, CA. Philadelphia (PA): AACR; Mol Cancer Res 2018;16(8_Suppl):Abstract nr A69.

Usefulness of Integrating Heart Failure Risk Factors Into Impairment of Global Longitudinal Strain to Predict Anthracycline-Related Cardiac Dysfunction

The prediction of cancer therapeutics-related cardiac dysfunction (CTRCD) is an essential aspect of care for individuals who receive potentially cardiotoxic oncologic treatments. Certain clinical risk factors have been described for incident CTRCD, and measurement of left ventricular (LV) longitudinal strain by speckle tracking 2-dimensional echocardiography (2DE) is the best-validated myocardial mechanical imaging assessment to detect subtle changes in LV function during cancer treatment. However, the direct integration of clinical and imaging risk factors to predict CTRCD has not yet been extensively examined. This was a retrospective study of 183 women with breast cancer aged 50.9 ± 10.8 years who received treatment with anthracyclines (doxorubicin dose of 422 ± 69 mg/m², with 41.2% of subjects also receiving trastuzumab) and underwent 2DE at clinically determined intervals. CTRCD was diagnosed when LV ejection fraction dropped ≥10% to a subnormal (<53%) value by 2DE. Left ventricular global longitudinal strain (LV-GLS) was assessed offline. The risk prediction tool based only on clinical factors previously described by Ezaz et al was applied to our cohort and accurately stratified these subjects into low-, intermediate-, and high-risk groups, with incident CTRCD in 7.4%, 26.9%, and 54.6%, respectively (chi-square = 20.7, p <0.0001). We developed novel multivariate models to predict CTRCD using (1) demographic variables only (c = 0.8674), (2) echocardiographic (peak LV-GLS) variables only (c = 0.8440), or (3) a combination of demographic and echocardiographic variables, with the combined model exhibiting superior receiver-operating characteristics (c = 0.9629). In conclusion, estimation of CTRCD risk should integrate all available data, including both clinical variables and an imaging assessment.

Abstract OT2-05-03: Does minocycline mitigate chemotherapy induced neuroinflammation? A phase II randomized placebo controlled study

Background: Many breast cancer (BC) patients, particularly those who receive chemotherapy (chemo), experience affective symptoms and cognitive changes that can negatively impact their quality of life. Causal links between inflammatory mediators and the development of depressive-like behavior and cognitive defects, have been established in mouse models, including studies by our group showing increased microglial activation following chemo (A.C DeVries et al). Microglia are resident immune cells of the brain, which release proinflammatory cytokines when activated. Doxorubicin (DOX) induces microglial activation in the brain. Minocycline, a second generation tetracycline, has been shown to suppress inflammation by inhibiting microglial activation in CNS disease models. We hypothesize that (1) chemo activates microglia in the brains of women being treated for BC, which can precipitate or exacerbate depression, anxiety and cognitive deficits and (2) Minocycline administration during neoadjuvant or adjuvant chemo will prevent chemo-induced microglial activation and will reduce affective and cognitive symptom burden. Trial Design: This is a single center, Phase II, double blinded randomized study of minocycline (100 mg twice a day) vs placebo twice a day in women with BC receiving DOX-based or other chemo for BC. Pts will be randomized to either oral minocycline or placebo for up to a 1 week loading period plus chemo treatment period and an optional subsequent 2 week period. Eligibility Criteria: Women diagnosed with BC stages I-III initiating first line adjuvant or neoadjuvant chemo. Aims: (1) to evaluate symptoms related to anxiety and depression and cognitive changes during and after chemo completion (2) to evaluate markers of neuro inflammation as assessed by blood based inflammatory cytokines and central markers of inflammation and microglia activation using 1 F-Fludeoxyglucose and 11C-PK11195 positron emission tomography. Primary endpoints are changes in Center for Epidemiological Studies Depression Scale (CES-D) and State Trait Anxiety Index (STAI) from baseline to end of study after minocycline vs placebo intervention. Secondary endpoints are changes in cognitive function during chemo using validated cognitive testing including N-Back Test, Behavioural Rating Inventory of Executive Function (BRIEF) and the Multifactorial Memory Questionnaire Ability Scale (MMQ). Statistical Methods: Primary analysis for efficacy will be intention-to-treat. The main objective is to preliminarily evaluate the effect of minocycline on chemo-induced depressive symptoms in terms of changes in CES-D and STAI scores. Mixed models will be used to evaluate cognitive function changes. A sample size of 23 per group, will give 80% power to detect an effect size of 0.74 standard deviation (SD) difference between the 2 groups at significance level of 0.10 based on a 2 sided two-sample t-test. From our experience, attrition of less than 20% is expected for studies in this patient population in our center, and to account for this, we plan to recruit up to 60 patients. 16 of 46 evaluable pts have been accrued to date. Accrual started in January 2016. Funded by Pelotonia grant from The OSUCCC. Contact: Study PI: Maryam.lustberg@osumc.edu

Citation Format: Boutrid H, Reinbolt R, Knopp M, Williams N, VanDeusen J, Sardesai S, Noonan A, Flora L, Gleich E, Pan X, Berger M, Vargo C, Wesolowski R, Ramaswamy B, DeVries AC, Lustberg M. Does minocycline mitigate chemotherapy induced neuroinflammation? A phase II randomized placebo controlled study [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT2-05-03.

Abstract CT033: Phase 1b study of heat shock protein 90 inhibitor onalespib in combination with paclitaxel in patients with advanced, triple-negative breast cancer (NCT02474173)

Background: Heat shock protein 90 (HSP90) is a molecular chaperone that is required for proper folding and stabilization of proteins. Client proteins of HSP90 include many mediators of signal transduction known to be over-activated in triple negative breast cancer such as AKT, EGFR, members of RAS/MAPK signaling pathways and androgen receptor. Expression of HSP90 has been found to be upregulated in multiple triple negative breast cancer cell lines and associated with poor outcome of breast cancer patients. In addition, over-expression of HSP90 client proteins such as AKT and c-RAF has been implicated in paclitaxel resistance. Onalespib (AT13387) is a synthetic non-ansamycin small molecule that acts as an inhibitor of HSP90 by binding to the amino terminal of the protein and has dissociation constant (Kd) of 0.71 nM.

Materials and Methods: Patients with inoperable or metastatic triple negative or weakly hormone receptor positive breast cancer are treated with onalespib and paclitaxel on days 1, 8, 15 every 28 days. Paclitaxel is given at a standard dose of 80 mg/m2 while the dose of onalespib is gradually increased using standard 3+3 design (see table). In order to assess the effect of each drug on pharmacokinetics of the other drug, onalespib is given on day -7 prior to cycle 1 and skipped on day 1 of cycle 1 during which paclitaxel in administered alone. The primary objective of the study is to determine recommended phase 2 dose and assess the toxicity profile of the combination. The secondary objectives include effect of onalespib on pharmacokinetics of paclitaxel and effect of paclitaxel on pharmacokinetics of onalespib. Overall response rate, response duration and progression-free survival will also be assessed. Dose Escalation ScheduleDose LevelDoseOnalespib (mg/m2 IV on days 1, 8, 15)Paclitaxel (mg/m2 IV on days 1, 8, 15)Level -110080Level 112080Level 215080Level 320080Level 426080

Conclusion: The study opened to accrual on January 15, 2016 and is currently enrolling the first 3 patients to dose level 1.

Citation Format: Robert Wesolowski, Maryam B. Lustberg, Ewa Mrozek, Rachel Layman, Raquel Reinbolt, Ming Poi, Nadia Osman, Andrea Lively, Julie Stephens, Michael Grever, Bhuvaneswari Ramaswamy. Phase 1b study of heat shock protein 90 inhibitor onalespib in combination with paclitaxel in patients with advanced, triple-negative breast cancer (NCT02474173). [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr CT033.

Abstract P1-09-03: Prevention of aromatase Inhibitor (AI)-induced joint symptoms with omega-3 fatty acid supplementation: A randomized placebo-controlled pilot study

Introduction: AI-induced joint symptoms negatively impact drug adherence and quality of life. Based on observations that n-3 polyunsaturated fatty acids (PUFAs) have anti-inflammatory effects and that the mechanism of AI-induced joint symptoms may be partly due to inflammation, we hypothesized that women taking more n-3 PUFAs are less likely to develop AI-induced joint symptoms.

Methods: We conducted a randomized, double-blind, placebo-controlled study comparing n-3 PUFA vs placebo in postmenopausal breast cancer patients starting adjuvant AIs. Participants were randomized to n-3 supplements [2.58 g eicosapentaenoic acid + 1.74 g docosahexaenoic acid/day; Marine Nutriceuticals, Mt. Bethel, PA] vs matched placebo for 24 weeks (wks). Primary endpoints was feasibility; secondary outcomes were self-reported symptoms as assessed by the Brief Pain Inventory short form (BPI-SF), Functional Assessment of Cancer Treatment, Breast & Endocrine Symptoms (FACTB-ES), and Stanford's Health Assessment and Disability Index (HAQ) at baseline prior to AI receipt, 12 and 24 wks. Compliance and toxicity were evaluated monthly. Serial peripheral blood n-3 PUFA levels and inflammatory cytokines (IL-6, TNFR2, IL-17) were drawn. MRI of hands/wrists was performed in selected patients using a 3 Tesla dedicated wrist coil at baseline and treatment end.

Results: Forty-four women were enrolled and randomized to study drug; 42 received ≥1 cycle (4 wks) of treatment; 36 had ≥1 post treatment evaluation at wk 12 or 24. Median age was 59.5 (range 43-76); history of prior taxane (n=15, 34%). The two groups’ baseline characteristics were similar. Overall, 93% and 88% of patients took &gt;80% of the placebo and n-3 PUFA doses, respectively. Baseline erythrocyte n-3 PUFA was similar for both groups (6.6% ± 1.6%, 7.2% ±1.9%, p=0.20), but higher in the n-3 PUFA arm by wk 24 (6.5%±1.0% vs 15.0%±3.3%, p&lt;0.001). Most toxicities were grade 1; the n-3 PUFA arm had only 1 (2.5%) grade 3 toxicity (diarrhea). The n-3 PUFA arm reported lower mean BPI-SF scores after treatment [(-.0.28/ -0.25 at week 12/24); but not statistically significant compared to placebo (p=0.494 and 0.601)]. Based on BPI-SF, the n-3 PUFA arm reported less interference of pain symptoms compared to placebo at 12 weeks (-.72, p=0.08). This arm also had a decreased walking, activity and working (WAW) score on BPI-SF at 12 weeks (-.81 p=0.05), and reported significantly greater pain relief from medications at 12 (p=0.043) and 24 weeks (p=0.011). Both arms had similar baseline and wk 24 serum IL-6 levels; levels decreased from baseline to wk 24 in the n-3 PUFA arm (-0.54±0.25, p=0.048). There was a non-significant trend (p= 0.2) toward decreased wrist inflammation by MRI imaging at 24 wks in the n-3 PUFA arm.

Conclusions: This is the first randomized pilot study to show that n-3 PUFA supplementation to prevent AI-induced joint symptoms is feasible and well tolerated. There is preliminary evidence that this intervention may help reduce the burden of AI-induced arthralgias.

OSU Study #11022; ClinicalTrials.gov Identifier: NCT01478477. Grants from the National Cancer Institute (CA037447-26) to the Alliance for Clinical Trials in Oncology supported this pilot study.

Citation Format: Maryam B Lustberg, Tonya Orchard, Xueliang Pan, Raquel Reinbolt, Amanda Logan, Joanne Lester, Rachel M Layman, Erin Macrae, Ewa Mrozek, Bhuvaneswari Ramaswamy, Robert Wesolowski, Michael Berger, Michael Knopp, Charles Loprinzi, Charles L Shapiro, Lisa Yee. Prevention of aromatase Inhibitor (AI)-induced joint symptoms with omega-3 fatty acid supplementation: A randomized placebo-controlled pilot study [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P1-09-03.

Stabilization of bone marrow infiltration by metastatic breast cancer with continuous doxorubicin

Complete bone marrow infiltration with profound pancytopenia is very uncommon in breast cancer. Bone marrow metastasis can frequently occur following development of metastatic breast cancer. However, bone marrow failure as the herald of this disease is not typically seen. Very limited data exists as to the safest and most efficacious manner to treat patients with profound pancytopenia due to metastatic solid tumor involvement. In this case, the patient’s thrombocytopenia was particularly worrisome, requiring daily platelet transfusions. There was also concern that cytotoxic chemotherapy would exacerbate the patient’s thrombocytopenia and increase bleeding risk. The patient’s dramatic response to chemotherapy with full platelet recovery is also highly unusual. For our patient, continuous doxorubicin successfully “unpacked” the bone marrow despite a low baseline platelet level, and without increasing the need for more frequent platelet transfusion or risk of catastrophic bleeding. Given the rarity of this presentation, it is currently unknown if the majority of similar patients experience near full recovery of hematopoietic function after initiation of appropriate systemic treatment for metastatic disease.

Severe and prolonged lymphopenia observed in patients treated with bendamustine and erlotinib for metastatic triple negative breast cancer

PURPOSE

Triple negative breast cancers (TNBC) frequently have high epidermal growth factor receptor (EGFR) expression and are sensitive to DNA-damaging agents. Improved therapies are needed for this aggressive malignancy.

PATIENTS AND METHODS

We performed a phase I trial of bendamustine and erlotinib, an EGFR tyrosine kinase inhibitor, in patients with metastatic TNBC, ECOG performance status ≤2, and ≤1 prior chemotherapy for metastatic disease. Each 28-day cycle included intravenous bendamustine on days 1, 2 and oral erlotinib on days 5-21 with dose escalation according to a 3 + 3 phase I study design. Dose-limiting toxicity (DLT) was determined by toxicities related to study therapy observed during cycle 1.

RESULTS

Eleven patients were treated, 5 on dose level 1 and 6 on dose level 2. One patient had DLT on dose level 2. However, cumulative toxicities were observed, including grade 3/4 lymphopenia in 91 % (95 % CI 0.59-0.998) with progressively decreased CD4 counts and grade ≥3 infections in 36 % (95 % CI 0.11-0.69) of patients.

CONCLUSIONS

Combination therapy with bendamustine and erlotinib causes excessive toxicity with severe, prolonged lymphopenia, depressed CD4 counts, and opportunistic infections and should not be pursued further. Future trials of bendamustine combinations in TNBC patients should account for potential cumulative lymphocyte toxicity necessitating patient monitoring during and after treatment.