Patient-reported outcomes in high-risk HR+ /HER2- early breast cancer patients treated with endocrine therapy with or without palbociclib within the randomized PENELOPEB study

BACKGROUND

The PENELOPEB trial investigating efficacy and safety of additional 1-year post-neoadjuvant palbociclib to standard endocrine therapy (ET) high-risk hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) early breast cancer patients failed to improve invasive disease-free survival (iDFS). This analysis compared patient-reported outcomes (PROs) between treatment groups.

PATIENTS AND METHODS

Patients received 13 cycles of palbociclib 125 mg/day (n = 631) or placebo (n = 619) orally for 3 out of 4 weeks + ET. European Organization for Research and Treatment of Cancer Quality-of-Life Questionnaire (EORTC QLQ-C30), its breast cancer (BR23) and fatigue (FA13) modules, mood questionnaire GAD7 and European Quality of Life 5 Dimensions (EQ-5D) instruments were used for the assessment of quality of life (QoL). Repeated-measures mixed-effects models were used to evaluate differences in PRO, changes of PRO over time, and treatment-by-time interactions.

RESULTS

924 of 1250 patients (73.9%) completed baseline and at least one post-baseline questionnaire of all PRO instruments. General health status (GHS)/QoL based on EORTC QLQ-C30 was high in both arms (mean [SD]: palbociclib 70.1 [19.3], placebo 71.4 [18.8]) and was slightly higher in the placebo arm (LeastSquare mean difference: 0.82, p < 0.001). Higher fatigue was reported in the palbociclib arm (mean [SD]: 30.3 [23.8] vs. placebo 28.3 [22.7]; p < 0.001). No statistically significant differences were observed among FA13 physical, cognitive, and emotional fatigue subscales.

CONCLUSION

Patient-reported global QoL and fatigue did not substantially change in both treatment arms. Slight differences in GHS, physical functioning, and fatigue favored the placebo arm statistically without achieving clinically meaningful thresholds.

Using Oncotype DX breast recurrence score® assay to define the role of neoadjuvant endocrine therapy in early-stage hormone receptor-positive breast cancer

PURPOSE

The role of neoadjuvant endocrine therapy in the treatment of patients with early-stage, hormone receptor-positive (HR +) breast cancer is not well defined. Tools to better determine which patients may benefit from neoadjuvant endocrine therapy versus chemotherapy or upfront surgery remain an unmet need.

METHODS

We assessed the rate of clinical and pathologic complete response (cCR, pCR) among a pooled cohort of patients with early-stage HR + breast cancer who had been randomized to neoadjuvant endocrine therapy or neoadjuvant chemotherapy in two earlier studies to understand better how outcomes varied by Oncotype DX Breast Recurrence Score® assay.

RESULTS

We observed that patients with intermediate RS results had no statistically significant differences in pathologic outcomes at the time of surgery based on whether they received neoadjuvant endocrine therapy or neoadjuvant chemotherapy, suggesting that a subgroup of women with a RS 0-25 may omit chemotherapy without compromising outcomes.

CONCLUSION

These data suggest that Recurrence Score® (RS) results may serve as a useful tool in treatment decision-making in the neoadjuvant setting.

Abstract A009: Association of neighborhood disadvantage with biomarkers of biological aging and chronic stress among breast cancer survivors. [R]

Living in a disadvantaged neighborhood is associated with adverse outcomes among breast cancer patients, but the underlying pathway is still unclear. Limited evidence has suggested that chronic stress and accelerated biological aging may play an important role. Biological aging and chronic stress are closely related, and both associated with mitochondrial dysfunction, abnormal DNA methylation, telomere shortening, etc. For example, allostatic load (AL), a biomarker of chronic stress, increases with age as a result of the cumulative effects of allostasis across the lifespan. In this study, we attempted to take the first step by evaluating the association of neighborhood disadvantage with biomarkers of chronic stress and biological aging among breast cancer patients. Using a sub-sample of 906 women with newly diagnosed breast cancer at M.D. Anderson, we examined whether levels of AL and selected biological aging biomarkers (global DNA methylation, telomere length, etc.) were affected by neighborhood disadvantage. The Area Deprivation Index (ADI) was used to measure the levels of neighborhood disadvantage. Telomere length and global DNA methylation in leukocytes were measured by qPCR and ELISA, respectively. We used 17 factors that represent the activity of five physiological systems to construct the AL score. Based on the median ADI at the national level, the study population was divided into low and high ADI groups. Overall, breast cancer patients from the high ADI group were more likely to be younger and non-Hispanic Black than those from the low ADI group (P&lt;0.001). They were also more likely to have higher stage and poorly differentiated breast tumors (P=0.029 and 0.019, respectively). For the relationship with markers, compared to the low ADI group, high ADI group had higher median levels of AL (P=0.046) and lower median levels of global DNA methylation (P&lt;0.001). Higher AL was considered as an indicator of increased chronic stress. Compared to their counterparts, those from the high ADI group were 20% and 32% more likely to have increased AL and telomerase activity, respectively, and 51% less likely to have increased levels of global DNA methylation. We also found that ADI was inversely correlated with telomere length. Additionally, we found that the significant associations of AL and global DNA methylation with ADI group were observed in non-Hispanic Whites and Blacks, but not in Hispanics. Lastly, using the mediation analysis, we found that decreased global DNA methylation mediated 6.52 and 7.98% of the association between higher ADI group with stage III and poorly differentiated tumor (P=0.037 and 0.023), respectively. In summary, we observed that neighborhood disadvantage was associated with more aggressive breast tumor characteristics, and influenced the levels of AL and global DNA methylation among breast cancer patients. Our findings suggest that neighborhood disadvantage is biologically embedded in molecular level and associated with accelerated biological aging and increased chronic stress among breast cancer patients.

Citation Format: Jie Shen, Hua Zhao, Bernard Fuemmeler, Vanessa Sheppard, Harry Bear. Association of neighborhood disadvantage with biomarkers of biological aging and chronic stress among breast cancer survivors. [R] [abstract]. In: Proceedings of the AACR Special Conference: Aging and Cancer; 2022 Nov 17-20; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_1):Abstract nr A009.

The epigenetic regulation of cancer cell recovery from therapy exposure and its implications as a novel therapeutic strategy for preventing disease recurrence

The ultimate goal of cancer therapy is the elimination of disease from patients. Most directly, this occurs through therapy-induced cell death. Therapy-induced growth arrest can also be a desirable outcome, if prolonged. Unfortunately, therapy-induced growth arrest is rarely durable and the recovering cell population can contribute to cancer recurrence. Consequently, therapeutic strategies that eliminate residual cancer cells reduce opportunities for recurrence. Recovery can occur through diverse mechanisms including quiescence or diapause, exit from senescence, suppression of apoptosis, cytoprotective autophagy, and reductive divisions resulting from polyploidy. Epigenetic regulation of the genome represents a fundamental regulatory mechanism integral to cancer-specific biology, including the recovery from therapy. Epigenetic pathways are particularly attractive therapeutic targets because they are reversible, without changes in DNA, and are catalyzed by druggable enzymes. Previous use of epigenetic-targeting therapies in combination with cancer therapeutics has not been widely successful because of either unacceptable toxicity or limited efficacy. The use of epigenetic-targeting therapies after a significant interval following initial cancer therapy could potentially reduce the toxicity of combination strategies, and possibly exploit essential epigenetic states following therapy exposure. This review examines the feasibility of targeting epigenetic mechanisms using a sequential approach to eliminate residual therapy-arrested populations, that might possibly prevent recovery and disease recurrence.

Abstract P5-13-36: Germline BRCA1/2 and other predisposition genes in high-risk early-stage HR+/HER2- breast cancer (BC) patients treated with endocrine therapy (ET) with or without palbociclib: A secondary analysis from the PENELOPE-B study

Background: In high-risk hormone-receptor (HR)+/HER2- BC patients germline (g) mutations can be found in approximately 14% in BRCA1/2 and in BRCA1/2 and other BC predisposition genes in 20% (Pohl-Rescigno E, et al. JAMA Oncol 2020). In metastatic BC CDK4/6 inhibitors may have greater activity in patients with a BRCA mutation detected in ctDNA (André F, et al. J Clin Oncol 2020). The PENELOPE-B trial did not to show an improved invasive disease-free survival (iDFS) by adding palbociclib to ET in high-risk HR+/HER2- BC (Loibl S, et al. J Clin Oncol 2021). Methods: Blood samples from 898 of 1250 PENELOPE-B patients were available. 445 patients were sampled following a case-cohort design (220 cases defined as patients with any event during follow-up and 225 randomly selected patients without any event [non-cases]) and analyzed for germline variants in BRCA1/2 and 16 non-BRCA1/2 cancer predisposition genes (ATM, BARD1, BRIP1, CDH1, CHEK2, FANCM, MRE11A, NBN, PALB2, PTEN, RAD50, RAD51C, RAD51D, STK11, TP53, XRCC2) by targeted next generation sequencing (NGS). The primary definition of mutational status was the prevalence of a pathogenic mutation (mt) in one or more analyzed BC predisposition genes. Statistical analyses for time-to-event endpoints (iDFS, distant disease-free survival [DDFS], and overall survival [OS]) were based on inverse probability weighting: weighted Cox proportional hazard models and Kaplan-Meier estimates were used. Results: 442 of 445 patients (placebo arm: 104 cases and 105 non-cases; palbociclib arm: 114 cases and 119 non-cases) were successfully analyzed for mutational status. A total of 42 (9.5%) patients (placebo arm: 9.1%; palbociclib arm: 9.9%) carried any mutation. 15 (3.4%) patients had a gBRCA1/2 mt (one of whom carried a gATM mt and one a gCHEK2 mt in addition to gBRCA2 mt) and 29 (6.6%) had mutations in one of the other BC predisposition genes (n=8 CHEK2, n=7 PALB2, n=5 ATM, n=2 RAD50, n=1 for BARD1, FANCM, MRE11A, RAD51C, RAD51D, TP53 and n=1 both RAD51D and BRIP1). The mutational status with respect to all genes analyzed showed no significant correlation to clinical baseline variables. With regard to gBRCA1 and gBRCA2 genes only, the mutational status significantly correlated with age but not with other clinical variables: all 15 (100%) gBRCA mt carriers were younger than 50 years compared to 238 (56%) wildtype (wt) patients (p=0.002). The iDFS rate after 3 years was 80.9% in patients with any mutation and 79.5% in patients without. Mutational status (mt vs. wt) based on all genes analyzed was not prognostic (iDFS: hazard ratio 1.015, 95%CI 0.558-1.784; DDFS: 0.970, 95%CI 0.521-1.758; OS: 0.768, 95%CI 0.274-1.615). Neither the mutated patients had a benefit from palbociclib treatment (palbociclib vs placebo; iDFS: hazard ratio 0.766, 95%CI 0.263-3.022; DDFS: 0.897, 95%CI 0.275-3.489; OS: 0.666, 95%CI 0.063-5.671) nor the wt patients (iDFS: hazard ratio 0.918, 95%CI 0.650-1.303; DDFS: 0.966, 95%CI 0.679-1.393; OS: 0.901, 95%CI 0.573-1.433); interaction tests for treatment arm/mutational status for all time-to-event endpoints were not statistically significant. Analysis in the subgroups of patients by gBRCA1/2 showed similar results but had less statistical power. Conclusions: In this case-cohort analysis of 442 patients enrolled in the PENELOPE-B trial, the detection of BC predisposition genes was lower than expected with 10%. This is probably due to the low rate of gBRCA1/2 carriers (3.4%), which could be influenced by the selection criteria of the trial. Patients with gBRCA1/2 or other BC disposition genes had a comparable outcome to non-carriers in the PENELOPE-B trial.

Citation Format: Sibylle Loibl, Jan Hauke, Karen Gelmon, Frederik Marmé, Corinna Ernst, Miguel Martin, Michael Untch, Hervé Bonnefoi, Erik Knudsen, Seock-Ah Im, Angela DeMichele, Laura Van’t Veer, Sung-Bae Kim, Harry Bear, Nicole McCarthy, Nicholas Turner, Agnieszka Witkiewicz, Federico Rojo, Peter A Fasching, José A García-Sáenz, Catherine M Kelly, Toralf Reimer, Masakazu Toi, Hope S Rugo, Carsten Denkert, Michael Gnant, Andreas Makris, Yuan Liu, Olga Valota, Bärbel Felder, Karsten Weber, Valentina Nekljudova, Eric Hahnen. Germline BRCA1/2 and other predisposition genes in high-risk early-stage HR+/HER2- breast cancer (BC) patients treated with endocrine therapy (ET) with or without palbociclib: A secondary analysis from the PENELOPE-B study [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-13-36.

Abstract P2-15-02: Using Oncotype DX Breast Recurrence Score® (RS) assay to define the role of neoadjuvant endocrine therapy (NET) in early-stage hormone receptor positive (HR+) breast cancer (BC)

Background:Adjuvant endocrine therapy remains the standard of care for patients (pts) with early stage, HR+ BC who can safely omit chemotherapy based on RS results; however, the role of NET remains unclear. There are limited data regarding the optimal duration of treatment with NET and the ideal patient (pt) population for NET in terms of age and RS result. This question rose to critical importance amidst the COVID-19 pandemic, during which NET was utilized more broadly in attempts to delay surgery or chemotherapy while preserving optimal pt outcomes. This study re-examines the use of NET among a cohort of pts with HR+ BC randomized to NET or neoadjuvant chemotherapy (NCT) based on RS (performed on initial core biopsy specimens).Methods:Data were pooled from two independent studies performed at Emory’s Winship Cancer Institute and Massey Cancer Center at Virginia Commonwealth University (VCU) from 2010-2012. These studies evaluated rates of clinical and pathologic complete response (pCR) among pts with early stage, HR+ BC assigned to treatment groups based on RS results. Pts with RS 0-10 received NET (Group (Grp) A), RS 11-24/25 (Emory 11-24 vs VCU 11-25) were randomized to NET (Grp B) or NCT (Grp C), and those with RS 25/26-100 received NCT (Grp D). Associations between RS result, neoadjuvant therapy and pCR in the breast, lymph nodes (LN) and breast plus LN were evaluated using Fisher’s exact test. Results:109 pts were included in this analysis. The Emory cohort was younger (median age 56 years (yrs) vs 63 yrs in VCU cohort) and more diverse (37.5% African American (AA) vs 18.6% AA in VCU cohort). The pts were predominantly post-menopausal (69.6% Emory vs 83.1% VCU). Nodal status among the Emory cohort was evenly divided with 50% N0 and 50% N+, while the majority of VCU pts were N0 (76.3% N0 vs 22.0% N+). Pts were grouped based on RS result: RS &lt;11 (18% Emory vs 20.3% VCU), RS 11-24/25 (36% Emory vs 55.9% VCU) and RS 24/25 or higher (46% Emory vs 23.7% VCU). Pts with low RS result were older (median 64 yrs vs 59 yrs among RS &gt; 24/25) with higher percentage of low-grade tumors (47.6% grade 1 vs 5.4% grade 1 among RS &gt;24/25). With regard to pCR, there were no significant differences among pts with low or intermediate RS results, as no pts in these groups achieved pCR in the breast or breast + LN (Table). Pts with RS result 25/26-100 (Grp D) were the only pts shown to achieve pCR in breast + LN (18.9%, p= 0.0043 across groups). Notably, while pts on the Emory study received longer courses of NET (median 10 months vs 5.5 months), there were no significant differences in pCR across RS result subgroups noted between the two institutions. Conclusion:Our results demonstrate that the use of Oncotype DX Breast Recurrence Score® or other genomic assays in the neoadjuvant setting may help guide treatment decisions when considering the use of NET versus NCT. Pt age and length of endocrine therapy as well as pt preferences should be considered when determining neoadjuvant treatment plans. There are currently ongoing studies evaluating the use of NET with CDK4/6 inhibitors that will offer further insight into optimal neoadjuvant treatment strategies in HR+ BC. Subsequent phase III evaluation of the role of genomic assays in the neoadjuvant setting is feasible and may help determine whether NET + CDK 4/6 inhibitors could replace NCT for pts with higher RS values.

Table: pCR according to treatment groups (All Eligible Patients)VariableGroup A (N=21)Group B (N=23)Group C (N=22)Group D (N=37)P value (a)pCR Breast0 (0.0%)0 (0.0%)0 (0.0%)8 (21.6%)0.0016pCR Nodes0 (0.0%)1 (4.3%)3 (13.6%)2 (5.6%)0.2977pCR Breast + Nodes0 (0.0%)0 (0.0%)0 (0.0%)7 (18.9%)0.0043(a) Fisher's exact test was used for categorical variables with cell counts &lt;5.Note: Group A= Recurrence Score &lt;11,Group B= Recurrence Score 11-24 (Emory study) or 11-25 (VCUstudy) receiving NET,Group C= Recurrence Score 11-24 (Emory study) or 11-25 (VCUstudy) receiving NCT,and Group D= Recurrence Score &gt;24 (Emory study) or &gt;25 (VCUstudy).Note: 1 patient did not receive SLNB(sentinel lymph node biopsy) or ALND (axillary lymph node dissection) and is excluded from the denominator for pCR Nodes.

Citation Format: Caitlin Taylor, Aimee Foreman, Christy Russell, Dipankar Bandyopdhyay, Xiaoyan Deng, Lisa Floyd, Amelia Zelnak, Ruth O'Regan, Harry Bear, Jane Meisel. Using Oncotype DX Breast Recurrence Score® (RS) assay to define the role of neoadjuvant endocrine therapy (NET) in early-stage hormone receptor positive (HR+) breast cancer (BC) [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-15-02.

Abstract PD2-04: Molecular plasticity of luminal breast cancer and response to CDK 4/6 inhibition - The biomarker program of the PENELOPE-B trial investigating post-neoadjuvant palbociclib

Background: Molecular plasticity of breast cancer is crucial for the development of therapy-resistant disease. In this investigation, we studied changes in molecular signatures between pretherapeutic (pre-Tx) and post-therapeutic (post-NACT) tumor samples from patients included in the PENELOPE-B (NCT01864746) trial. The phase III PENELOPE-B study did not show a significant benefit from palbociclib in women with centrally confirmed HR+, HER2- primary breast cancer without a pathological complete response after taxane-containing neoadjuvant chemotherapy (NACT) and at high-risk of relapse (CPS-EG score ≥3 or 2 and ypN+) (Loibl et al. JCO 2021). However, first translational investigations showed that a small number of patients with a luminal-B tumor subtype, based on absolute intrinsic molecular subtyping (AIMS, Paquet & Hallet, JNCI 2014) subtyping after NACT, had a numerical benefit from post-NACT palbociclib. We have therefore extended the analysis and included a cohort of paired pre-Tx and post-NACT samples. Methods: We investigated gene expression in pre-Tx (n=259) tumor tissue samples using the HTG EdgeSeq Oncology Biomarker Panel including 2549 genes (HTG Molecular Diagnostics Inc.); for the same patients the same panel on post-NACT residual tumor samples were available. The paired samples were selected based on a case-cohort approach. Based on 91 genes of this panel, the AIMS subtype was calculated. In addition, we performed exploratory biomarker analyses to identify genes and gene signatures with prognostic and predictive relevance. After completion of NACT, PENELOPE-B patients were randomized to palbociclib versus placebo in addition to standard endocrine therapy. Results: The prevalence of AIMS subtypes, in particular LumA vs LumB, changed in pre-Tx and post-NACT tumors. In the pre-Tx samples, 115 (44%) and 123 (47%) of tumors had LumA and LumB subtypes, respectively, as expected from a high-risk cohort. However, in the post-NACT samples, LumA tumors were predominant (n=183, 71%) over LumB (n=30; 12%). 78 (30%) and 6 (2%) tumors switched their subtype from LumB to LumA and LumA to LumB, respectively. For further analyses, we compared the groups of low proliferating (LumA and NormL) and high proliferating subtypes (LumB, BasalL and HER2E). In bivariable Cox regression analysis, the grouped pre-Tx and post-NACT AIMS subtypes were independent prognostic factors for iDFS: HR=1.85 (1.16-2.98, p=0.011) for pre-Tx LumB/BasalL/HER2E vs LumA/NormL and HR=2.18 (1.24-3.84, p=0.007) for post-NACT. Similar results were found when adjusted for prognostic clinical factors and for DDFS and OS endpoints although the pre-Tx subtype did not reach significance. These and further Cox models investigating interaction effects show that patients with tumors developing from high (pre-Tx) to low proliferation (post-NACT) had a higher iDFS risk compared to stable low proliferating tumors but a lower iDFS risk compared to stable high proliferating tumors. Neither in the pre-Tx LumB/BasalL/HER2E nor in the pre-Tx LumA/NormL subgroup a benefit from palbociclib was observed. Based on the results of the AIMS subtyping, we extended the exploratory analysis to identify genes that might be involved in the prognostic and predictive effects as well as genes driving the subtype switch. The analysis is ongoing and the relevant genes will be presented at the conference. Conclusions: Our findings show that the switch from high-risk molecular subtypes (in particular LumB) to low-risk subtypes (in particular LumA) is common in neoadjuvant therapy of luminal tumors. The adaptation of luminal high-risk tumors to therapy-induced stress is crucial for the clinical outcome and the results suggest that molecular defined tumor subtypes might not be as stable as originally thought.

Citation Format: Carsten Denkert, Frederik Marmé, Miguel Martin, Michael Untch, Hervé Bonnefoi, Sung-Bae Kim, Harry Bear, Agnieszka Witkiewicz, Seock-Ah Im, Angela DeMichele, Laura Van’t Veer, Nicole McCarthy, Thorsten Stiewe, Karen A. Gelmon, José A. García-Sáenz, Catherine M. Kelly, Toralf Reimer, Erik Knudsen, Nicholas Turner, Federico Rojo, Peter A. Fasching, Julia Teply-Szymanski, Yuan Liu, Masakazu Toi, Hope S. Rugo, Michael Gnant, Andreas Makris, Bärbel Felder, Karsten Weber, Sibylle Loibl. Molecular plasticity of luminal breast cancer and response to CDK 4/6 inhibition - The biomarker program of the PENELOPE-B trial investigating post-neoadjuvant palbociclib [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr PD2-04.

Palbociclib for Residual High-Risk Invasive HR-Positive and HER2-Negative Early Breast Cancer-The Penelope-B Trial

PURPOSE

About one third of patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative breast cancer who have residual invasive disease after neoadjuvant chemotherapy (NACT) will relapse. Thus, additional therapy is needed. Palbociclib is a cyclin-dependent kinase 4 and 6 inhibitor demonstrating efficacy in the metastatic setting.

PATIENTS AND METHODS

PENELOPE-B (NCT01864746) is a double-blind, placebo-controlled, phase III study in women with hormone receptor-positive, human epidermal growth factor receptor 2-negative primary breast cancer without a pathological complete response after taxane-containing NACT and at high risk of relapse (clinical pathological staging-estrogen receptor grading score ≥ 3 or 2 and ypN+). Patients were randomly assigned (1:1) to receive 13 cycles of palbociclib 125 mg once daily or placebo on days 1-21 in a 28-day cycle in addition to endocrine therapy (ET). Primary end point is invasive disease-free survival (iDFS). Final analysis was planned after 290 iDFS events with a two-sided efficacy boundary P < .0463 because of two interim analyses.

RESULTS

One thousand two hundred fifty patients were randomly assigned. The median age was 49.0 years (range, 19-79), and the majority were ypN+ with Ki-67 ≤ 15%; 59.4% of patients had a clinical pathological staging-estrogen receptor grading score ≥ 3. 50.1% received aromatase inhibitor, and 33% of premenopausal women received a luteinizing hormone releasing hormone analog in addition to either tamoxifen or an aromatase inhibitor. After a median follow-up of 42.8 months (92% complete), 308 events were confirmed. Palbociclib did not improve iDFS versus placebo added to ET-stratified hazard ratio, 0.93 (95% repeated CI, 0.74 to 1.17) and two-sided weighted log-rank test (Cui, Hung, and Wang) P = .525. There was no difference among the subgroups. Most common related serious adverse events were infections and vascular disorders in 113 (9.1%) patients with no difference between the treatment arms. Eight fatal serious adverse events (two palbociclib and six placebo) were reported.

CONCLUSION

Palbociclib for 1 year in addition to ET did not improve iDFS in women with residual invasive disease after NACT.

Promoting antitumor immunity and increased T-cell function by depletion and blockade of the immunosuppressive cell compartment in murine cancer

Tumor growth occurs due to a failure of the immune system to recognize and destroy malignant cells. The cause of breakdown in immune surveillance is at the systemic level and at in the tumor microenvironment. These changes can even occur in the tumor cells themselves to make them less detectable by anticancer immune cells such as downregulation of tumor-associated antigens or decreased expression of antigen presenting molecules such as MHCI. In addition, many cancer types will upregulate immune checkpoint molecules, such as PD-L1 which binds to PD-1 on cytotoxic T-cells to suppress antitumor immune cell function. Immune surveillance can also be curtailed by the presence of immunosuppressive cells such as myeloid-derived suppressor cells (MDSCs) and T-regulatory cells (T-regs) which both serve to dampen antitumor immunity. Our lab utilizes a metronomic low-dose therapeutic approach to examine the effects of anticancer drugs against murine breast cancer and the effects on the immunosuppressive cell compartments. Recent data has shown a reduction in T-regs following treatment with cyclophosphamide, a common chemotherapy. We have also shown that guadecitabine, a second-generation DNA methyl-transferase inhibitor, depletes MDSCs. Here we show that combining low-dose metronomic treatments of guadecitabine and cyclophosphamide leads to a depletion in splenic and tumor MDSCs and T-regs, increased CD8+ T-cell function in the tumor, as well as a reduction in tumor size in FoxP3 reporter mice bearing triple-negative 4T1 tumors. In addition, preliminary studies suggest this antitumor effect is amplified by combining guadecitabine and cyclophosphamide with checkpoint inhibitors such as anti-PD-1, in vivo.

Metronomic low dose cyclophosphamide in combination with a DNA methyltransferase inhibitor limits tumor growth in murine triple negative breast cancer

Many breast cancers are treated with therapies that target herceptin, estrogen, or progesterone receptors; however, for triple-negative breast cancers (TNBC) that lack these receptors, treatment options are limited, and prognosis is often unfavorable. The goal of this study is to design a therapeutic intervention that can elicit an effective immune response against the tumor and instill immunological memory to eradicate primary and metastatic lesions. Guadecitabine (Guad) is a second-generation DNA methyltransferase inhibitor (DMNTi) that has been reported to have several antitumor properties such as increased antigenicity and depletion of myeloid-derived suppressor cells (MDSC’s). Cyclophosphamide is a FDA approved chemotherapy that has been shown, when given as a low-dose treatment, to selectively deplete regulatory T-cells (T-regs). Both MDSCs and T-regs suppress antitumor immunity. We hypothesize that the combination of Guad and Cyp will synergize and promote anticancer immunity through increased expression of de novo tumor antigens and depletion of MDSCs and T-regs in a low-dose setting. To test this hypothesis, BALB/c mice were challenged with murine TNBC 4T1 tumor cells and the 4T1-bearing mice were administered low-dose Guad and Cyp daily for ten consecutive days. This experiment showed a degree of synergy between Guad and Cyp with the dual therapy reducing tumor burden to a greater extent than either monotherapy.

Two may be better than one: PD-1/PD-L1 blockade combination approaches in metastatic breast cancer

Antibodies blocking programmed death 1 (anti-PD-1) or its ligand (anti-PD-L1) are associated with modest response rates as monotherapy in metastatic breast cancer, but are generally well tolerated and capable of generating dramatic and durable benefit in a minority of patients. Anti-PD-1/L1 antibodies are also safe when administered in combination with a variety of systemic therapies (chemotherapy, targeted therapies), as well as with radiotherapy. We summarize preclinical, translational, and preliminary clinical data in support of combination approaches with anti-PD-1/L1 in metastatic breast cancer, focusing on potential mechanisms of synergy, and considerations for clinical practice and future investigation.

Current Landscape of Immunotherapy in Breast Cancer: A Review

Importance

There is tremendous interest in using immunotherapy to treat breast cancer, as evidenced by the more than 290 clinical trials ongoing at the time of this narrative review. The objective of this review is to describe the current status of immunotherapy in breast cancer, highlighting its potential in both early-stage and metastatic disease.

Observations

After searching ClinicalTrials.gov on April 24, 2018, and PubMed up to June 30, 2018, to identify breast cancer immunotherapy trials, we found that immune checkpoint blockade (ICB) is the most investigated form of immunotherapy in breast cancer. Use of ICB as monotherapy has achieved objective responses in patients with breast cancer, with higher rates seen when administered in earlier lines of therapy. For responding patients, those responses are durable. More recent data suggest clinical efficacy when ICB is given in combination with chemotherapy. Ongoing studies are evaluating combination strategies pairing ICB with additional chemotherapeutic agents, targeted therapy, vaccines, and local ablative therapies to enhance response. To date, robust predictive biomarkers for response to ICB have not been established.

Conclusions and Relevance

It is anticipated that combination therapy strategies will be the way forward for immunotherapy in breast cancer, with an improved understanding of tumor, microenvironment, and host factors informing treatment combination decisions. Thoughtful study design incorporating appropriate end points and correlative studies will be critical in identifying optimal strategies for enhancing the immune response against breast tumors.

The DNA methyltransferase inhibitor, Guadecitabine, shifts myeloid derived suppressor cell phenotype from immune-suppressive toward immune-stimulatory

Immune-evasion is a difficult obstacle to overcome in cancer therapy. Through the epigenetic modifications of DNA methylation and the recruitment of immunoregulatory myeloid-derived suppressor cells (MDSCs), tumors are able to dampen the body’s anti-tumor response. Here we show that the DNA methyltransferase inhibitor, Guadecitabine, is an effective tool for altering both tumor and MDSC phenotype. Treatment of 4T1 murine mammary carcinoma cells in vitro with Guadecitabine caused a significant increase in MHC I. In MDSCs, Guadecitabine caused an increased expression of MHC II and CD86, and enhanced antigen uptake. Additionally, Guadecitabine-treated MDSCs had a reduced capacity to block T cell proliferation, at least in part due to diminished nitric oxide production. In vivo, we established 4T1 flank carcinomas for 10 days prior to administering Guadecitabine. The resulting tumor size was markedly reduced and the characteristic splenomegaly from MDSC accumulation was largely reversed. Importantly, Guadecitabine did not affect resident lymphocyte populations in the spleen or infiltration to the tumor. Overall, these results suggest that Guadecitabine may be an effective therapy to boost the patient’s own immune response against cancer.

Morbidity and mortality meetings at Australian major trauma centres: A proof of concept study

Background

Morbidity and mortality meetings are held at all Australian major trauma centres and provide a forum to identify problems and improve practices. Meetings should focus on addressing factors in the system to prevent similar errors occurring, rather than individual culpability. This paper describes current meeting practices and assesses the use of a systems approach.

Methods

This proof of concept study used a convenience sample of four Australian major trauma centres. Trauma leaders at each centre were surveyed regarding morbidity and mortality meeting practices. The use of a systems approach was measured by assessing practices against the London Protocol for Systems Analysis of Clinical Incidents. Meeting participants were also surveyed regarding perceptions of the objectives and effectiveness of meetings.

Results

This study found variable utilisation of a systems approach. Cases are not routinely analysed for contributing system factors and effective processes are not always used to correct problems that are identified. Meeting practices also vary between centres in terms of frequency, case selection criteria and use of audit filters. Participants generally view quality improvement as the most important objective of meetings.

Conclusion

Morbidity and mortality meeting practices vary between Australian major trauma centres and a systems approach has not been fully adopted.

Randomized sham controlled trial of cranial microcurrent stimulation for symptoms of depression, anxiety, pain, fatigue and sleep disturbances in women receiving chemotherapy for early-stage breast cancer

Purpose

Women with breast cancer may experience symptoms of depression, anxiety, pain, fatigue and sleep disturbances during chemotherapy. However, there are few modalities that address multiple, commonly occurring symptoms that may occur in individuals receiving cancer treatment. Cranial electrical stimulation (CES) is a treatment that is FDA cleared for depression, anxiety and insomnia. CES is applied via electrodes placed on the ear that deliver pulsed, low amplitude electrical current to the head.

Methods

This phase III randomized, sham-controlled study aimed to examine the effects of cranial microcurrent stimulation on symptoms of depression, anxiety, pain, fatigue, and sleep disturbances in women receiving chemotherapy for early-stage breast cancer. Patients were randomly assigned to either an actual or sham device and used the device daily for 1 h. The study was registered at clinicaltrials.gov, NCT00902330.

Results

The sample included N = 167 women with early-stage breast cancer. Symptom severity of depression, anxiety, and fatigue and sleep disturbances were generally mild to moderate. Levels of pain were low. Anxiety was highest prior to the initial chemotherapy and decreased over time. The primary outcome assessment (symptoms of depression, anxiety, fatigue, pain, sleep disturbances) revealed no statistically significant differences between the two groups, actual CES vs. sham.

Conclusion

In this study, women receiving chemotherapy for breast cancer experienced multiple symptoms in the mild to moderate range. Although there is no evidence for the routine use of CES during the chemotherapy period for symptom management in women with breast cancer, further symptom management modalities should be evaluated to mitigate symptoms of depression, anxiety, fatigue, pain and sleep disturbances over the course of chemotherapy.

Electronic supplementary material

The online version of this article (doi:10.1186/s40064-015-1151-z) contains supplementary material, which is available to authorized users.

Adoptive cellular therapy containing T cells and CD25+ NKT cells modulates myeloid cells and stimulates endogenous anti-tumor immune function (VAC7P.1038)

Myeloid-derived suppressor cells (MDSCs) are a type of myeloid regulatory cell (Mreg) that suppresses the anti-tumor activity of immune effector cells. We have previously demonstrated that CD25+ NKT cells function as cellular adjuvants for converting MDSC into immune stimulatory myeloid cells, thereby rescuing anti-tumor T cell function from MDSCs in vitro. Here, we sought to characterize the in vivo efficacy of adoptive cellular therapy (ACT) utilizing reprogrammed T cells and CD25+ NKT cells in modulating MDSCs in FVBN202 mice. We demonstrate a significant 2-fold decrease in the frequency and absolute number of splenic MDSCs in recipients of ACT compared with control mice bearing comparable lung metastases. We also observed a significant 2-fold increase in the frequency and absolute number of mature myeloid cells (CD11b-MHC-II+CD40+CD86+). Functional analysis was performed in which CD11b- myeloid cells from ACT-recipient animals bearing lung metastases were cultured with autologous splenocytes. CD11b- MHC II+ cells induced a significant release of splenocyte-derived IFN-γ; this response was enhanced greater than 20-fold upon the addition of tumor cells. Importantly, ACT recipients of mice bearing Ki-67hi circulating tumor cells experienced extended time to progression compared to control animals. These data suggest CD25+ NKT cells may act to promote ‘vaccination in situ’ of endogenous T cells, in addition to boosting anti-tumor efficacy of ACT.

Cancer immunotherapy: treatment of established breast cancer or prevention of tumor relapse and metastasis? (TUM2P.903)

Cancer vaccines and adoptive immunotherapies (AITs) are being tested both in preventive and therapeutic settings. In order to determine the most effective immunotherapeutic strategy, we investigated the efficacy of AIT against established advanced carcinoma and minimal residual disease. We used Decitabine to improve immunogenicity of the tumor cells by inducing the expression of cancer testis antigens (CTA), in vivo. Tumor-sensitized immune cells were activated and reprogrammed, ex vivo, using bryostatin 1 and ionomycin, along with IL-2, IL-7, and IL-15; this produced a central memory phenotype in 73% of T cells, and an activated phenotype in 27% of NK cells and 94% of NKT cells. FVBN202 transgenic mice were protected from developing lung metastases following AIT, but failed to cure established lung metastases. The reprogrammed immune cells also demonstrated immunological memory that protected animals from recall tumor challenge. In vitro studies showed that reprogrammed immune cells were able to kill 82% of viable Adriamycin-treated quiescent tumor cells. Our results suggest that AIT could be efficacious against chemotherapy-resistant dormant tumor cells in a setting of low tumor burden and prevent distant metastasis of breast cancer. These findings are significant because breast cancer mortality results from metastatic disease that develops from residual tumor cells remaining dormant, sometimes for prolonged periods following conventional therapies.

Mast cells and mast cell-derived IL-13 play an important role in MDSC activation, migration, and accumulation. (TUM4P.925)

Until recently, the interaction between mast cells (MCs) and CD11b+Gr-1+ myeloid derived suppressor cells (MDSCs) was limited to recruitment of MDSCs to the tumor site. However, we report that MCs are also needed for the activity of MDSCs. Adoptive transfer (AT) of MDSCs failed to promote B16 melanoma colonization in MC deficient mice. MDSCs in these mice also failed to localize to the liver and stayed mainly in peripheral blood. MC sufficient mice accumulated MDSCs in the liver and retained significantly lower levels of MDSCs in circulation after AT. Recently, Ma et al. (Cancer Res. 2013 Jul 1; 73(13);3927-37.) has shown that MC derived IL-13 has been show to promote the growth of pancreatic ductal carcinoma. Given this, we investigated the role that IL-13 plays in the MDSC/MC interaction. Our data shows that IL-13 KO mice crossed to ADAM10Tg mice, which carry a mutation resulting in the over-accumulation of MDSCs, have significantly decreased MDSC accumulation in the naïve state, especially evident in the granulocytic subset. In a model of natural MDSC accumulation (Lewis Lung Carcinoma, i.v.), IL-13 KO mice had reduced tumor colonization to the lungs. They also had reduced MDSC accumulation in the liver and spleen, but increased number in circulation. Taken together, our data indicates that MCs and IL-13, an important MC-derived cytokine, play an important role in MDSC migration and accumulation and represent important drug targets for the control of MDSCs in tumor.

Mast cell derived histamine promotes the activity of monocytic myeloid derived suppressor cells (P2065)

Until recently, the interaction between mast cells (MCs) and CD11b+Gr-1+ myeloid derived suppressor cells (MDSCs) was limited to recruitment of MDSCs to the tumor site. However, we report that MCs are also needed for the activity of MDSCs. MDSCs failed to promote B16 melanoma metastasis in MC deficient mice. This was dependent on monocytic Ly6C+ MDSCs while granulocytic Ly6G+ had no effect. In vitro studies showed increased Th2 cytokine production by both cells. Given these observations and literature indicating histamine as a promoter of tumor expansion, myeloid cell proliferation, and Th2 skewed immunity; we investigated histamine in the MC/MDSC interaction. MDSCs were shown to express histamine receptor 1 (HR1). Furthermore, histamine enhanced MDSC survival and preferentially expanded monocytic LY6C+ MDSCs. This was abrogated with HR1 antagonization. Additionally, histamine upregulated Arg1 and iNOS enzyme expression, both of which are utilized by MDSCs to inhibit T cell activity. This was further supported by the finding that in the presence of MCs, MDSCs were more effective at inhibiting T cell proliferation. Taken together, our data indicates that beyond recruitment, MCs regulate MDSC activity at the tumor site via histamine release. These findings have important implications for the use of anti-histamines in cancer patients being simultaneously treated for allergies. Oncologists should consider this new MC/MDSC interaction when determining therapeutic interventions.

Mast cells activate MDSC to promote inflammation (177.2)

Mast cells play an important role in promoting inflammation, controlling parasitic infection, and potentiating allergic disease. Conversely, myeloid-derived suppressor cells (MDSC) are found in tumor-bearing individuals and in models of septic shock, where they are known to have regulatory effect. We aimed to determine a possible role for interactions between MDSC and mast cells and the effect of these interactions in a mouse model of parasitic infection. Surprisingly, co-culture of these cells resulted in a drastic increase in pro-inflammatory mediator release, which was attributed entirely to MDSC. Depletion of MDSC from mice infected with Nippostrongylus brasiliensis resulted in delayed worm expulsion and a drastically increased intestinal worm burden. Conversely, this inflammatory role of MDSC seems detrimental when inflammation is chronic, as MDSC depletion in an airway hyperresponsiveness model decreased the pathology of this disease. Interestingly, we have found that mast cell conditioned-media activates both the STAT3 and ERK pathways in MDSC, which could represent a novel means of pro-inflammatory cytokine induction in MDSC. We therefore conclude that mast cells can reprogram MDSC to a pro-inflammatory phenotype, suggesting that the evolutionary purpose of these suppressive cells may be to potentiate inflammatory Th2 responses necessary for parasite expulsion.

The role of Tyk2 in regulation of breast cancer growth

The antigrowth and immunomodulatory actions of interferons (IFNs) have enabled these cytokines to be used therapeutically for the treatment of a variety of hematologic and solid malignancies. IFNs exert their effects by activation of the Jak/Stat signaling pathway. IFNγ stimulates the tyrosine kinases Jak1 and Jak2, resulting in activation of the Stat1 transcription factor, whereas type 1 IFNs (IFNα/β) activate Jak1 and Tyk2, which mediate their effects through Stat1 and Stat2. Disruption in the expression of IFNγ, IFNα receptors, or Stat1 inhibits antitumor responses and blunt cancer immunosurveillance in mice. Mutations in Jak2 or constitutive activation of Jak1 or Jak2 also promote the development of a variety of malignancies. Although there are data indicating that Tyk2 plays a role in the pathogenesis of lymphomas, the effects of Tyk2 expression on tumorigenesis are unknown. We report here that Tyk2(-/-) mice inoculated with 4T1 breast cancer cells show enhanced tumor growth and metastasis compared to Tyk2(+/+) animals. Accelerated growth of 4T1 cells in Tyk2(-/-) animals does not appear to be due to decreased function of CD4(+), CD8(+) T cells, or NK cells. Rather, the tumor suppresive effects of Tyk2 are mediated at least in part by myeloid-derived suppressor cells, which appear to be more effective in inhibiting T cell responses in Tyk2(-/-) mice. Our results provide the first evidence for a role of Tyk2 in suppressing the growth and metastasis of breast cancer.

Mast cells induce a novel pro-inflammatory function of myeloid-derived suppressor cells (151.2)

Mast cells and myeloid-derived suppressor cells (MDSC) are both increased at sites of growing tumors. Like mast cells, MDSC have recently been suggested to function in parasitic or bacterial infection. We have tested the effects of mast cell-MDSC interactions in vitro and in a mouse model of parasitic infection. Surprisingly, co-culture of these cells resulted in a drastic increase in pro-inflammatory mediator release, which was attributed entirely to MDSC. MDSC depletion from mice infected with Nippostrongylus brasiliensis resulted in delayed worm expulsion and a drastically increased intestinal worm burden reminiscent of mast cell-deficient mice. Mast cells can therefore reprogram MDSC to a pro-inflammatory phenotype, suggesting that the evolutionary purpose of these suppressive cells may be to potentiate inflammatory Th2 responses necessary for parasite expulsion.

Predictive Factors for Positive Non-Sentinel Nodes Following a Positive Sentinel Node Biopsy: NSABP B-32

Background: Following a positive sentinel node biopsy (SNB), current guidelines recommend an axillary dissection (AD) regardless of SN metastatic tumor size. In the majority of clinically node negative patients the risk for positive non-sentinel axillary nodes (NSN) is low. Predictive factors for positive NSNs following a positive SNB are analyzed in NSABP B-32 with inclusion of SN metastatic tumor size.Materials and Methods: After stratification, women with operable invasive breast cancer and clinically negative nodes were randomized to Sentinel Node Resection (SNR) with immediate conventional Axillary Dissection (AD) [Group 1] or to SNR without AD [Group 2]. Group 2 patients with positive SNs underwent AD. A multivariate analysis of SN positive patients from both groups for whom both a SNR and an AD had been performed was used to assess the need for AD following SNB. Nodes were classified as either SNs or NSNs, defined as all axillary dissection nodes plus any intramammary or other nodes that were not resected as SNs.Results: Between May 1999 and February 2004, 5,611 patients were entered into NSABP Protocol B-32. There were a total of 1,361 SN positive patients with AD from both groups. Data from 1,166 patients were available for multivariate analysis which included SN metastatic tumor size in 735 patients: 424 patients with macrometastaes (&gt;2 mm) and 311 with micrometastases (&lt;2 mm). In 626 patients SN metastatic size was unknown.In patients with positive SNB, results from the final multivariate model based on 653 patients with known covariate values indicated clinical tumor size was a significant predictor for positive NSN (p=0.044, OR: 1.17). Lymphovascular invasion was a significant predictor for positive NSN (p=0.0004, OR: 1.85). SN metastatic tumor size (Macro vs Micro) was a highly significant predictor for positive NSN (p&lt;0.0001, OR: 3.42). Age at study entry, treatment type, proposed type of surgery, HER-2 status, and location of tumor were not significant multivariate predictors for positive NSN. Predictive modeling for positive NSN probability will be presented.Conclusion: Completion AD following a positive SNB, although helpful in prognosis and treatment planning, may not be required in patients with small tumors, absence of lymphovascular invasion, and micrometastases.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 301.

Variation in the use of breast-conserving therapy for Medicare beneficiaries in Virginia: clinical, geographic, and hospital characteristics

BACKGROUND

Treatment for early-stage breast cancer has evolved significantly in recent years. Breast-conserving therapy (BCT) has been shown to offer equivalent survival compared to traditional mastectomy. However, there is marked variation in the performance of BCT which may not reflect clinical appropriateness or patient preference. Little is known about the factors related to variation in BCT performance in older women with early-stage breast cancer.

METHODS

Retrospective claims analysis of 1,512 Medicare patients using part-A data for the years 1992 to 1993, with additional explicit chart review. A clinical algorithm was developed to categorize patients according to their candidacy for BCT and compare this to their treatment. Demographic, clinical, and geographic variables were included in the model.

RESULTS

The overall BCT rate in Virginia was 20%, with marked variation among providers of all types. BCT rates ranged from 0% to 44% among hospitals caring for more than 12 cases per year. Twenty-six percent of patients considered good candidates for BCT by current guidelines received this option. Large urban hospitals had significantly higher rates of BCT than smaller hospitals, regardless of the presence of radiation oncology capability. Distance from radiation oncology facilities was a factor in low BCT rates of rural populations, but low BCT rates also were present even in facilities with access to radiation oncology services.

CONCLUSIONS

These data present a detailed analysis of the patterns of BCT for Virginia Medicare beneficiaries with early-stage breast cancer. Clinical contraindications to BCT for confirmed early-stage disease were uncommon. Despite similar patient profiles and hospital-reported range of cancer services, marked variation in BCT rates exists. A large number of patients chose traditional mastectomy over BCT due to fears of radiation, but few received radiation oncology consultation. BCT rates were highest in hospitals with radiation oncology facilities on grounds; hospitals with facilities nearby had rates similar to those without access to radiation facilities. Patient preferences are documented poorly. This study provides further evidence that many women are receiving BCT in patterns that may not reflect clinical appropriateness for BCT nor access to necessary facilities.

Colorectal cancer in young adults

This retrospective study reviews our experience of the management of colorectal cancer in 481 consecutive patients. Details of presentation, surgery, Dukes staging, histological grading, recurrence and survival were analysed. We have compared patients 50 years of age and over with their younger counterparts. Thirty-six (7.5%) were less than 50 years of age. Half of the older group presented to hospital within 3 months of the onset of symptoms. Only 17.5% of the younger group presented so promptly (p less than 0.01). There was a higher proportion of younger patients with metastatic disease at the time of presentation. While there was no evidence to suggest a more aggressive surgical approach in the younger patients, 27.8% had adjuvant therapy compared with only 14.2% of the over 50s (p less than 0.05). The median survival was significantly better in the younger group (p less than 0.02).