Adjuvant platinum versus capecitabine for residual, invasive, triple-negative breast cancer: Patient-reported outcomes in ECOG-ACRIN EA1131

BACKGROUND

Patient-reported outcomes (PROs) are a better tool for evaluating the experiences of patients who have symptomatic, treatment-associated adverse events (AEs) compared with clinician-rated AEs. The authors present PROs assessing health-related quality of life (HRQoL) and treatment-related neurotoxicity for adjuvant capecitabine versus platinum on the Eastern Cooperative Oncology Group-American College of Radiology Imaging Network (ECOG-ACRIN) EA1131 trial (ClinicalTrials.gov identifier NCT02445391).

METHODS

Participants completed the National Comprehensive Cancer Network Functional Assessment of Cancer Therapy-Breast Cancer Symptom Index (NFBSI-16) and the Functional Assessment of Cancer Therapy-Gynecologic Oncology Group neurotoxicity subscale (platinum arm only) at baseline, cycle 3 day 1 (C3D1), 6 months, and 15 months. Because of early termination, power was insufficient to test the hypothesis that HRQoL, as assessed by the NFBSI-16 treatment side-effect (TSE) subscale, would be better at 6 and 15 months in the capecitabine arm; all analyses were exploratory. Means were compared by using t-tests or the Wilcoxon rank-sum test, and proportions were compared by using the χ2 test.

RESULTS

Two hundred ninety-six of 330 eligible patients provided PROs. The mean NFBSI-16 TSE subscale score was lower for the platinum arm at baseline (p = .02; absolute difference, 0.6 points) and for the capecitabine arm at C3D1 (p = .04; absolute difference, 0.5 points), but it did not differ at other times. The mean change in TSE subscale scores differed between the arms from baseline to C3D1 (platinum arm, 0.15; capecitabine arm, -0.72; p = .03), but not from baseline to later time points. The mean decline in Functional Assessment of Cancer Therapy-Gynecologic Oncology Group neurotoxicity subscale scores exceeded the minimal meaningful change (1.38 points) from baseline to each subsequent time point (all p < .05).

CONCLUSIONS

Despite the similar frequency of clinician-rated AEs, PROs identified greater on-treatment symptom burden with capecitabine and complemented clinician-rated AEs by characterizing patients' experiences during chemotherapy.

Germline predictors for bevacizumab induced hypertensive crisis in ECOG-ACRIN 5103 and BEATRICE

BACKGROUND

Bevacizumab is a beneficial therapy in several advanced cancer types. Predictive biomarkers to better understand which patients are destined to benefit or experience toxicity are needed. Associations between bevacizumab induced hypertension and survival have been reported but with conflicting conclusions.

METHODS

We performed post-hoc analyses to evaluate the association in 3124 patients from two phase III adjuvant breast cancer trials, E5103 and BEATRICE. Differences in invasive disease-free survival (IDFS) and overall survival (OS) between patients with hypertension and those without were compared. Hypertension was defined as systolic blood pressure (SBP) ≥ 160 mmHg (n = 346) and SBP ≥ 180 mmHg (hypertensive crisis) (n = 69). Genomic analyses were performed to evaluate germline genetic predictors for the hypertensive crisis.

RESULTS

Hypertensive crisis was significantly associated with superior IDFS (p = 0.015) and OS (p = 0.042), but only IDFS (p = 0.029; HR = 0.28) remained significant after correction for prognostic factors. SBP ≥ 160 mmHg was not associated with either IDFS or OS. A common single-nucleotide polymorphism, rs6486785, was significantly associated with hypertensive crisis (p = 8.4 × 10-9; OR = 5.2).

CONCLUSION

Bevacizumab-induced hypertensive crisis is associated with superior outcomes and rs6486785 predicted an increased risk of this key toxicity.

PACE: A Randomized Phase II Study of Fulvestrant, Palbociclib, and Avelumab After Progression on Cyclin-Dependent Kinase 4/6 Inhibitor and Aromatase Inhibitor for Hormone Receptor-Positive/Human Epidermal Growth Factor Receptor-Negative Metastatic Breast Cancer

PURPOSE

Cyclin-dependent kinase (CDK) 4/6 inhibitors (CDK4/6is) are an important component of treatment for hormone receptor-positive/human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (MBC), but it is not known if patients might derive benefit from continuation of CDK4/6i with endocrine therapy beyond initial tumor progression or if the addition of checkpoint inhibitor therapy has value in this setting.

METHODS

The randomized multicenter phase II PACE trial enrolled patients with hormone receptor-positive/HER2- MBC whose disease had progressed on previous CDK4/6i and aromatase inhibitor (AI) therapy. Patients were randomly assigned 1:2:1 to receive fulvestrant (F), fulvestrant plus palbociclib (F + P), or fulvestrant plus palbociclib and avelumab (F + P + A). The primary end point was investigator-assessed progression-free survival (PFS) in patients treated with F versus F + P.

RESULTS

Overall, 220 patients were randomly assigned between September 2017 and February 2022. The median age was 57 years (range, 25-83 years). Most patients were postmenopausal (80.9%), and 40% were originally diagnosed with de novo MBC. Palbociclib was the most common previous CDK4/6i (90.9%). The median PFS was 4.8 months on F and 4.6 months on F + P (hazard ratio [HR], 1.11 [90% CI, 0.79 to 1.55]; P = .62). The median PFS on F + P + A was 8.1 months (HR v F, 0.75 [90% CI, 0.50 to 1.12]; P = .23). The difference in PFS with F + P and F + P + A versus F was greater among patients with baseline ESR1 and PIK3CA alterations.

CONCLUSION

The addition of palbociclib to fulvestrant did not improve PFS versus fulvestrant alone among patients with hormone receptor-positive/HER2- MBC whose disease had progressed on a previous CDK4/6i plus AI. The increased PFS seen with the addition of avelumab warrants further investigation in this patient population.

De Novo Oligometastatic Breast Cancer

De novo oligometastatic breast cancer, a unique disease needing new treatment paradigms.

Impact of BMI in Patients With Early Hormone Receptor-Positive Breast Cancer Receiving Endocrine Therapy With or Without Palbociclib in the PALLAS Trial

PURPOSE

BMI affects breast cancer risk and prognosis. In contrast to cytotoxic chemotherapy, CDK4/6 inhibitors are given at a fixed dose, irrespective of BMI or weight. This preplanned analysis of the global randomized PALLAS trial investigates the impact of BMI on the side-effect profile, treatment adherence, and efficacy of palbociclib.

METHODS

Patients were categorized at baseline according to WHO BMI categories. Neutropenia rates were assessed with univariable and multivariable logistic regression. Time to early discontinuation of palbociclib was analyzed with Fine and Gray competing risk models. Unstratified Cox models were used to investigate the association between BMI category and time to invasive disease-free survival (iDFS). 95% CIs were derived.

RESULTS

Of 5,698 patients included in this analysis, 68 (1.2%) were underweight, 2,082 (36.5%) normal weight, 1,818 (31.9%) overweight, and 1,730 (30.4%) obese at baseline. In the palbociclib arm, higher BMI was associated with a significant decrease in neutropenia (unadjusted odds ratio for 1-unit change, 0.93; 95% CI, 0.91 to 0.94; adjusted for age, race ethnicity, region, chemotherapy use, and Eastern Cooperative Oncology Group at baseline, 0.93; 95% CI, 0.92 to 0.95). This translated into a significant decrease in treatment discontinuation rate with higher BMI (adjusted hazard ratio [HR] for 10-unit change, 0.75; 95% CI, 0.67 to 0.83). There was no significant improvement in iDFS with the addition of palbociclib to ET in any weight category (normal weight HR, 0.84; 95% CI, 0.63 to 1.12; overweight HR, 1.10; 95% CI, 0.82 to 1.49; and obese HR, 0.95; 95% CI, 0.69 to 1.30) in this analysis early in follow-up (31 months).

CONCLUSION

This preplanned analysis of the PALLAS trial demonstrates a significant impact of BMI on side effects, dose reductions, early treatment discontinuation, and relative dose intensity. Additional long-term follow-up will further evaluate whether BMI ultimately affects outcome.

Circulating tumor DNA association with residual cancer burden after neoadjuvant chemotherapy in triple-negative breast cancer in TBCRC 030

BACKGROUND

We aimed to examine circulating tumor DNA (ctDNA) and its association with residual cancer burden (RCB) using an ultrasensitive assay in patients with triple-negative breast cancer (TNBC) receiving neoadjuvant chemotherapy.

PATIENTS AND METHODS

We identified responders (RCB 0/1) and matched non-responders (RCB 2/3) from the phase II TBCRC 030 prospective study of neoadjuvant paclitaxel versus cisplatin in TNBC. We collected plasma samples at baseline, 3 weeks and 12 weeks (end of therapy). We created personalized ctDNA assays utilizing MAESTRO mutation enrichment sequencing. We explored associations between ctDNA and RCB status and disease recurrence.

RESULTS

Of 139 patients, 68 had complete samples and no additional neoadjuvant chemotherapy. Twenty-two were responders and 19 of those had sufficient tissue for whole-genome sequencing. We identified an additional 19 non-responders for a matched case-control analysis of 38 patients using a MAESTRO ctDNA assay tracking 319-1000 variants (median 1000 variants) to 114 plasma samples from 3 timepoints. Overall, ctDNA positivity was 100% at baseline, 79% at week 3 and 55% at week 12. Median tumor fraction (TFx) was 3.7 × 10-4 (range 7.9 × 10-7-4.9 × 10-1). TFx decreased 285-fold from baseline to week 3 in responders and 24-fold in non-responders. Week 12 ctDNA clearance correlated with RCB: clearance was observed in 10 of 11 patients with RCB 0, 3 of 8 with RCB 1, 4 of 15 with RCB 2 and 0 of 4 with RCB 3. Among six patients with known recurrence, five had persistent ctDNA at week 12.

CONCLUSIONS

Neoadjuvant chemotherapy for TNBC reduced ctDNA TFx by 285-fold in responders and 24-fold in non-responders. In 58% (22/38) of patients, ctDNA TFx dropped below the detection level of a commercially available test, emphasizing the need for sensitive tests. Additional studies will determine whether ctDNA-guided approaches can improve outcomes.

Stromal heterogeneity may explain increased incidence of metaplastic breast cancer in women of African descent

The biologic basis of genetic ancestry-dependent variability in disease incidence and outcome is just beginning to be explored. We recently reported enrichment of a population of ZEB1-expressing cells located adjacent to ductal epithelial cells in normal breasts of women of African ancestry compared to those of European ancestry. In this study, we demonstrate that these cells have properties of fibroadipogenic/mesenchymal stromal cells that express PROCR and PDGFRα and transdifferentiate into adipogenic and osteogenic lineages. PROCR + /ZEB1 + /PDGFRα+ (PZP) cells are enriched in normal breast tissues of women of African compared to European ancestry. PZP: epithelial cell communication results in luminal epithelial cells acquiring basal cell characteristics and IL-6-dependent increase in STAT3 phosphorylation. Furthermore, level of phospho-STAT3 is higher in normal and cancerous breast tissues of women of African ancestry. PZP cells transformed with HRasG12V ± SV40-T/t antigens generate metaplastic carcinoma suggesting that these cells are one of the cells-of-origin of metaplastic breast cancers.

Impact of Muscle Measures on Outcome in Patients Receiving Endocrine Therapy for Metastatic Breast Cancer: Analysis of ECOG-ACRIN E2112

BACKGROUND

Observational data investigating the relationship between body habitus and outcomes in breast cancer have been variable and inconsistent, largely centered in the curative setting and focused on weight-based metrics. This study evaluated the impact of muscle measures on outcomes in patients with metastatic breast cancer receiving endocrine-based therapy.

METHODS

Baseline CT scans were collected from ECOG-ACRIN E2112, a randomized phase III placebo-controlled study of exemestane with or without entinostat. A CT cross-sectional image at the L3 level was extracted to obtain skeletal muscle mass and attenuation. Low muscle mass (LMM) was defined as skeletal muscle index <41 cm2/m2 and low muscle attenuation (LMA) as muscle density <25 HU or <33 HU if overweight/obese by body mass index (BMI). Multivariable Cox proportional hazard models determined the association between LMM or LMA and progression-free survival (PFS) and overall survival (OS). Correlations between LMM, LMA, and patient-reported outcomes were determined using 2-sample t tests.

RESULTS

Analyzable CT scans and follow-up data were available for 540 of 608 patients. LMM was present in 39% (n=212) of patients and LMA in 56% (n=301). Those with LMA were more likely to have obesity and worse performance status. LMM was not associated with survival (PFS hazard ratio [HR]: 1.13, P=.23; OS HR: 1.05, P=.68), nor was LMA (PFS HR: 1.01, P=.93; OS HR: 1.00, P=.99). BMI was not associated with survival. LMA, but not LMM, was associated with increased frequency of patient-reported muscle aches.

CONCLUSIONS

Both low muscle mass and density are prevalent in patients with hormone receptor-positive metastatic breast cancer. Muscle measures correlated with obesity and performance status; however, neither muscle mass nor attenuation were associated with prognosis. Further work is needed to refine body composition measurements and select optimal cutoffs with meaningful endpoints in specific breast cancer populations, particularly those living with metastatic disease.

ADAM8 is expressed widely in breast cancer and predicts poor outcome in hormone receptor positive, HER-2 negative patients

BACKGROUND

Breast malignancies are the predominant cancer-related cause of death in women. New methods of diagnosis, prognosis and treatment are necessary. Previously, we identified the breast cancer cell surface protein ADAM8 as a marker of poor survival, and a driver of Triple-Negative Breast Cancer (TNBC) growth and spread. Immunohistochemistry (IHC) with a research-only anti-ADAM8 antibody revealed 34.0% of TNBCs (17/50) expressed ADAM8. To identify those patients who could benefit from future ADAM8-based interventions, new clinical tests are needed. Here, we report on the preclinical development of a highly specific IHC assay for detection of ADAM8-positive breast tumors.

METHODS

Formalin-fixed paraffin-embedded sections of ADAM8-positive breast cell lines and patient-derived xenograft tumors were used in IHC to identify a lead antibody, appropriate staining conditions and controls. Patient breast cancer samples (n = 490) were used to validate the assay. Cox proportional hazards models assessed association between survival and ADAM8 expression.

RESULTS

ADAM8 staining conditions were optimized, a lead anti-human ADAM8 monoclonal IHC antibody (ADP2) identified, and a breast staining/scoring control cell line microarray (CCM) generated expressing a range of ADAM8 levels. Assay specificity, reproducibility, and appropriateness of the CCM for scoring tumor samples were demonstrated. Consistent with earlier findings, 36.1% (22/61) of patient TNBCs expressed ADAM8. Overall, 33.9% (166/490) of the breast cancer population was ADAM8-positive, including Hormone Receptor (HR) and Human Epidermal Growth Factor Receptor-2 (HER2) positive cancers, which were tested for the first time. For the most prevalent HR-positive/HER2-negative subtype, high ADAM8 expression identified patients at risk of poor survival.

CONCLUSIONS

Our studies show ADAM8 is widely expressed in breast cancer and provide support for both a diagnostic and prognostic value of the ADP2 IHC assay. As ADAM8 has been implicated in multiple solid malignancies, continued development of this assay may have broad impact on cancer management.

Cytochrome P450 Oxidoreductase (POR) Associated with Severe Paclitaxel-Induced Peripheral Neuropathy in Patients of European Ancestry from ECOG-ACRIN E5103

PURPOSE

Paclitaxel is a widely used anticancer therapeutic. Peripheral neuropathy is the dose-limiting toxicity and negatively impacts quality of life. Rare germline gene markers were evaluated for predicting severe taxane-induced peripheral neuropathy (TIPN) in the patients of European ancestry. In addition, the impact of Cytochrome P450 (CYP) 2C8, CYP3A4, and CYP3A5 metabolizer status on likelihood of severe TIPN was also assessed.

EXPERIMENTAL DESIGN

Whole-exome sequencing analyses were performed in 340 patients of European ancestry who received a standard dose and schedule of paclitaxel in the adjuvant, randomized phase III breast cancer trial, E5103. Patients who experienced grade 3-4 (n = 168) TIPN were compared to controls (n = 172) who did not experience TIPN. For the analyses, rare variants with a minor allele frequency ≤ 3% and predicted to be deleterious by protein prediction programs were retained. A gene-based, case-control analysis using SKAT was performed to identify genes that harbored an imbalance of deleterious variants associated with increased risk of severe TIPN. CYP star alleles for CYP2C8, CYP3A4, and CYP3A5 were called. An additive logistic regression model was performed to test the association of CYP2C8, CYP3A4, and CYP3A5 metabolizer status with severe TIPN.

RESULTS

Cytochrome P450 oxidoreductase (POR) was significantly associated with severe TIPN (P value = 1.8 ×10-6). Six variants were predicted to be deleterious in POR. There were no associations between CYP2C8, CYP3A4, or CYP3A5 metabolizer status with severe TIPN.

CONCLUSIONS

Rare variants in POR predict an increased risk of severe TIPN in patients of European ancestry who receive paclitaxel.

TONSL Is an Immortalizing Oncogene and a Therapeutic Target in Breast Cancer

Study of genomic aberrations leading to immortalization of epithelial cells has been technically challenging due to the lack of isogenic models. To address this, we used healthy primary breast luminal epithelial cells of different genetic ancestry and their hTERT-immortalized counterparts to identify transcriptomic changes associated with immortalization. Elevated expression of TONSL (Tonsoku-like, DNA repair protein) was identified as one of the earliest events during immortalization. TONSL, which is located on chromosome 8q24.3, was found to be amplified in approximately 20% of breast cancers. TONSL alone immortalized primary breast epithelial cells and increased telomerase activity, but overexpression was insufficient for neoplastic transformation. However, TONSL-immortalized primary cells overexpressing defined oncogenes generated estrogen receptor-positive adenocarcinomas in mice. Analysis of a breast tumor microarray with approximately 600 tumors revealed poor overall and progression-free survival of patients with TONSL-overexpressing tumors. TONSL increased chromatin accessibility to pro-oncogenic transcription factors, including NF-κB and limited access to the tumor-suppressor p53. TONSL overexpression resulted in significant changes in the expression of genes associated with DNA repair hubs, including upregulation of several genes in the homologous recombination (HR) and Fanconi anemia pathways. Consistent with these results, TONSL-overexpressing primary cells exhibited upregulated DNA repair via HR. Moreover, TONSL was essential for growth of TONSL-amplified breast cancer cell lines in vivo, and these cells were sensitive to TONSL-FACT complex inhibitor CBL0137. Together, these findings identify TONSL as a regulator of epithelial cell immortalization to facilitate cancer initiation and as a target for breast cancer therapy.

SIGNIFICANCE

The chr.8q24.3 amplicon-resident gene TONSL is upregulated during the initial steps of tumorigenesis to support neoplastic transformation by increasing DNA repair and represents a potential therapeutic target for treating breast cancer.

Circulating tumor DNA association with residual cancer burden after neoadjuvant chemotherapy in triple-negative breast cancer in TBCRC 030

Purpose

To examine circulating tumor DNA (ctDNA) and its association with residual cancer burden (RCB) using an ultrasensitive assay in patients with triple-negative breast cancer (TNBC) receiving neoadjuvant chemotherapy (NAT).

Patients and Methods

We identified responders (RCB-0/1) and matched non-responders (RCB-2/3) from the phase II TBCRC 030 prospective study of neoadjuvant paclitaxel vs. cisplatin in TNBC. We collected plasma samples at baseline, three weeks, and twelve weeks (end of therapy). We created personalized ctDNA assays utilizing MAESTRO mutation enrichment sequencing. We explored associations between ctDNA and RCB status and disease recurrence.

Results

Of 139 patients, 68 had complete samples and no additional NAT. Twenty-two were responders and 19 of those had sufficient tissue for whole-genome sequencing. We identified an additional 19 non-responders for a matched case-control analysis of 38 patients using a MAESTRO ctDNA assay tracking 319-1000 variants (median 1000) to 114 plasma samples from 3 timepoints. Overall, ctDNA positivity was 100% at baseline, 79% at week 3, and 55% at week 12. Median tumor fraction (TFx) was 3.7 × 10 -4 (range: 7.9 × 10 -7 to 4.9 × 10 -1 ). TFx decreased 285-fold from baseline to week 3 in responders and 24-fold in non-responders. Week 12 ctDNA clearance correlated with RCB: clearance was observed in 10/11 patients with RCB-0, 3/8 with RCB-1, 4/15 with RCB-2, and 0/4 with RCB-3. Among 6 patients with known recurrence five had persistent ctDNA at week 12.

Conclusion

NAT for TNBC reduced ctDNA TFx by 285-fold in responders and 24-fold in non-responders. In 58% (22/38) of patients, ctDNA TFx dropped below the detection level of a commercially available test, emphasizing the need for sensitive tests. Additional studies will determine if ctDNA-guided approaches can improve outcomes.

Abstract GS3-06: GS3-06 Palbociclib After CDK4/6i and Endocrine Therapy (PACE): A Randomized Phase II Study of Fulvestrant, Palbociclib, and Avelumab for Endocrine Pre-treated ER+/HER2- Metastatic Breast Cancer

Background CDK4/6 inhibitors (CDK4/6i) in combination with endocrine therapy (ET) have a well-established role in the management of hormone receptor-positive (HR+)/HER2- metastatic breast cancer (MBC). The benefit of continuing CDK4/6i beyond progression in combination with a different ET has not been confirmed. Preclinical data suggest synergy between CDK4/6i and PD-L1 inhibition. The PACE trial prospectively evaluates whether continuation of the CKD4/6i palbociclib beyond progression on prior CDK4/6i and aromatase inhibitor (AI), with a change in ET to fulvestrant, improves outcomes beyond change to fulvestrant alone, as well as explores the activity of the palbociclib, fulvestrant, and avelumab triplet. Methods PACE is a multicenter randomized open-label investigator-initiated phase II trial, open at 11 U.S. sites. Eligible patients (pts) had HR+/HER2- evaluable MBC with prior progression on AI and any CDK4/6i after &gt; 6 months (mo) of therapy in the MBC setting, or during/within 12 mo in the adjuvant setting, with no more than 1 prior line of chemotherapy for MBC. Pts were randomized 1:2:1 to fulvestrant alone (F); fulvestrant and palbociclib (F+P); or fulvestrant, palbociclib, avelumab (F+P+A), with tumor assessments every 8 weeks. Blood for circulating tumor DNA (ctDNA) analysis was collected at baseline, at times of tumor assessments, and at progression. The primary objective was to evaluate progression-free survival (PFS) with F+P vs F; secondary objectives included PFS with F+P+A vs F, objective response rate (ORR) in all arms, and safety. A sample size of 220 patients was planned to provide 80% power to detect an improvement in PFS with HR 0.6154 with F+P vs F (6.5 vs 4 mo; α(1)=0.05). Results A total of 220 pts were randomized from 9/2017-2/2022 (F: n=55, F+P: n=111, F+P+A: n=54); median age 57 years (range 25-83), 85% non-Hispanic (7.7% non-Hispanic black), 8.6% Hispanic, 6.4% unknown. 40% had de novo MBC, 60% had visceral disease, and 14% bone-only disease. 16% had 1 prior line of chemotherapy for MBC, 90% had received prior palbociclib, 4.5% ribociclib, 4.1% abemaciclib, 1.4% palbociclib and ribociclib. Pts entered the trial after a median 19 mo of prior CDK4/6i plus AI (interquartile range 12-31 mo). A total of 10 (5%) pts received protocol therapy as first line ET for MBC, 169 (77%) as second line, and 41 (17%) as beyond second line. 88% entered the trial directly after progression on CDK4/6i. After a median follow-up of 24 mo, 18 pts remained on protocol treatment. PFS was not improved with F+P vs F (median 4.6 vs 4.8 mo; HR=1.11, 90% CI 0.79-1.55; 2-sided p=0.62). Median PFS was 8.1 mo with F+P+A (HR=0.75 vs F, 90% CI 0.50-1.12; 2-sided p=0.23). ORR was 7.3% (90%CI 1.5-13.0) with F, 9.0% F+P (4.5-13.5%) and 13.0% F+P+A (5.4-20.5%). No new safety signals have been observed. Analysis of ctDNA panel sequencing encompassing 70 genes from 184 baseline samples, including correlation with known and hypothesized resistance genes, will be presented. Conclusions For ER+/HER2- breast cancer, combining palbociclib with fulvestrant beyond progression on prior CDK4/6i and AI did not significantly improve PFS compared with using fulvestrant alone. The observed longer PFS when a PD-L1 inhibitor was added to fulvestrant plus palbociclib is an intriguing signal in this ER+ population. Translational studies of blood and tumor tissue are ongoing and will be presented.

Citation Format: Erica L. Mayer, Yue Ren, Nikhil Wagle, Reshma Mahtani, Cynthia Ma, Angela DeMichele, Massimo Cristofanilli, Jane Meisel, Kathy D. Miller, Trevor Jolly, Elizabeth Riley, Rubina Qamar, Priyanka Sharma, Sonya Reid, Natalie Sinclair, Meredith Faggen, Caroline Block, Naomi Ko, Ann Partridge, Wendy Y. Chen, Michelle K. DeMeo, Victoria Attaya, Amanda Okpoebo, Yuan Liu, Eric Gauthier, Harold Burstein, Meredith Regan, Sara Tolaney. GS3-06 Palbociclib After CDK4/6i and Endocrine Therapy (PACE): A Randomized Phase II Study of Fulvestrant, Palbociclib, and Avelumab for Endocrine Pre-treated ER+/HER2- Metastatic Breast Cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr GS3-06.

Abstract OT2-16-01: ONCX-NAV-G201: A phase 2, basket study of navicixizumab monotherapy or in combination with chemotherapy in patients with select advanced solid tumors: Triple-negative breast cancer cohort (trial in progress)

Objective: The objective of this Phase 2, open-label, multicenter study is to investigate the antitumor activity of navicixizumab monotherapy or in combination with chemotherapy in patients with advanced solid tumors. Cohort C will enroll triple-negative breast cancer (TNBC) patients. Background: Navicixizumab is a bispecific humanized monoclonal immunoglobulin G2 kappa antibody directed against human delta-like ligand 4, a critical ligand of the NOTCH pathway, and human vascular endothelial growth factor (VEGF). Aberrant NOTCH signaling is associated with chemotherapy resistance, tumor plasticity, enhanced metastatic potential, promotion of a cancer stem cell phenotype, and immune evasion. In TNBC, aberrant NOTCH expression is associated with poor prognosis, making targeting of this pathway an attractive therapeutic strategy. Additionally, NOTCH may mediate resistance to angiogenesis inhibition. While VEGF inhibitors are approved for the treatment of multiple solid tumors, observed anti-tumor activity is limited in breast cancer. Pre-clinical data show that co-inhibition of NOTCH and angiogenesis have superior antitumor activity compared to individual pathway targeting. We postulate that navicixizumab will demonstrate anticancer efficacy against TNBC. Methods: Eligible TNBC patients will have locally advanced or metastatic disease and have received at least 2 and no more than 4 prior lines of standard therapy for metastatic disease, including immunotherapy (for PD-L1 positive TNBC patients), and sacituzumab govitecan. TNBC is defined as ER and PR &lt; 1%, and HER2-negative (IHC 0, 1+, or 2+ and negative fluorescence in situ hybridization [FISH]). Formalin-fixed paraffin-embedded tissue from an archival or a core tumor sample must be available for biomarker analysis. Samples will be tested using Oncomap™ ExTra with the Xerna TME Panel™ to classify patient samples into one of four tumor microenvironment (TME) subtypes based on angiogenic and immune gene expression signatures. Up to 30 patients will be enrolled to each TNBC cohort from approximately 8 sites in the US and will receive 3 mg/kg navicixizumab alone (Cohort C1) or in combination with paclitaxel (80 mg/m2 on Days 1, 8, and 15 of a 28-day cycle) (Cohort C2). Patients will have radiologic tumor assessments every 8 weeks and will continue to receive treatment until disease progression per RECIST v1.1 (as assessed by the investigator), unacceptable toxicity, withdrawal of consent, another protocol-defined discontinuation criterion is met, or the sponsor terminates the study, whichever occurs first. The primary endpoints of the study are objective response rate (ORR) and progression-free survival (PFS). The historical benchmarks for this patient population are estimated at an ORR of &lt; 5% and a 20% PFS rate at 4 months, with targets of 15% and 40% respectively considered promising for this study. Interim efficacy assessments will be at 10-patient increments following the time patients have had at least 1 post-baseline scan. Cohort continuation and future evaluation decisions will be guided by the boundaries identified by a sequential monitoring procedure. Secondary efficacy endpoints include overall survival, time to response, disease control rate, duration of response, and the relationship between antitumor activity of navicixizumab and Xerna TME Panel™ biomarker subtypes.

Citation Format: Amelia B. Zelnak, Heinz-Josef Lenz, Kerry Culm, Lukas Makris, Valerie Chamberlain Santos, Hagop Youssoufian, Colleen Mockbee, Kathy D. Miller. ONCX-NAV-G201: A phase 2, basket study of navicixizumab monotherapy or in combination with chemotherapy in patients with select advanced solid tumors: Triple-negative breast cancer cohort (trial in progress) [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr OT2-16-01.

Abstract P3-05-26: Association of muscle mass and density with outcomes in patients with ER positive metastatic breast cancer: correlative analysis of ECOG-ACRIN 2112

Introduction: Observational data investigating the relationship between body habitus and survival or toxicity in breast cancer has been largely centered in the curative setting and focused on weight- based metrics, with variable and inconsistent results. Muscle is a large, active endocrine organ that affects physical function, drug metabolism, inflammation, and quality of life, but is not adequately measured by body weight alone. Very few studies have evaluated muscle measures in metastatic breast cancer (MBC) and have been focused on patients receiving cytotoxic chemotherapy. Here, we evaluate the impact of muscle mass and muscle density measured on CT scan on outcomes in patients with MBC receiving endocrine- based therapy. Methods: Baseline CT scans done at the time of study enrollment were centrally collected from participants in ECOG-ACRIN E2112, a randomized phase III study of exemestane with or without entinostat in MBC, which ultimately did not impact survival. A transverse cut at the L3 level was extracted and processed using semi-automated SliceOmatic software (Tomovision) by two independent investigators to obtain total body skeletal muscle mass and muscle attenuation. Low muscle mass was defined as skeletal muscle index (SMI, lean muscle area/height, cm2/m2) less than 41 and low skeletal muscle attenuation (SMA) was defined as average muscle density less than 41 HU, or less than 33 HU if the patient is overweight or obese by BMI. Chi-square tests were used to determine the association between SMI and SMA and other clinical characteristics, including body weight, race, and performance status. Multivariable Cox proportional hazard models were used to determine the association between low SMI or low SMA and overall survival (OS), progression free survival (PFS), and patient- reported outcomes. Results: Of the 608 patients randomized in E2112, 546 had analyzable CT scans and follow up data available. 45% (n=246) of participants had obesity by BMI (≥30); 39% (n=212) had low SMI and 56% (n=305) had low SMA. Obese patients were more likely to have higher SMI (p&lt; 0.001); however, 9.5% (n=52) of the study population had both obesity and low SMI. Low SMA was associated with higher rate of obesity and worse performance status (p&lt; 0.001), consistent with muscle quality being a predictor of functional status. Low SMI was not associated with survival outcomes (OS HR 1.04 95%CI 0.83-1.30, PFS HR 1.12 95% CI 0.92-1.36), nor was low SMA (OS HR 1.02 95%CI 0.81-1.28; PFS HR 1.02 95%CI 0.84-1.23). In addition, BMI was not related to survival outcomes. Conclusions: Low muscle mass and low muscle density are prevalent in estrogen receptor positive MBC patients. Muscle measures correlated with obesity and performance status; however, neither low SMI nor low SMA were associated with worse prognosis in this population. Further work is needed to refine body composition measurements and select optimal cutoffs and meaningful endpoints in specific breast cancer populations, particularly in those living with metastatic disease.

Citation Format: Tarah J. Ballinger, Gloria Xue, Helga S. Marques, Constantine Gatsonis, Richard Hoffman, Kathy D. Miller, Fengmin Zhao, Joseph Sparano, Roisin Connolly. Association of muscle mass and density with outcomes in patients with ER positive metastatic breast cancer: correlative analysis of ECOG-ACRIN 2112 [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-05-26.

Initial Phase I Safety Study of Gedatolisib plus Cofetuzumab Pelidotin for Patients with Metastatic Triple-Negative Breast Cancer

PURPOSE

The PI3K pathway is dysregulated in the majority of triple-negative breast cancers (TNBC), yet single-agent inhibition of PI3K has been ineffective in TNBC. PI3K inhibition leads to an immediate compensatory upregulation of the Wnt pathway. Dual targeting of both pathways is highly synergistic against TNBC models in vitro and in vivo. We initiated a phase I clinical trial combining gedatolisib, a pan-class I isoform PI3K/mTOR inhibitor, and cofetuzumab pelidotin, an antibody-drug conjugate against the cell-surface PTK7 protein (Wnt pathway coreceptor) with an auristatin payload.

PATIENTS AND METHODS

Participants (pt) had metastatic TNBC or estrogen receptor (ER) low (ER and PgR < 5%, HER2-negative) breast cancer, and had received at least one prior chemotherapy for advanced disease. The primary objective was safety. Secondary endpoints included overall response rate (ORR), clinical benefit at 18 weeks (CB18), progression-free survival (PFS), and correlative analyses.

RESULTS

A total of 18 pts were enrolled in three dose cohorts: gedatolisib 110 mg weekly + cofetuzumab pelidotin 1.4 mg/kg every 3 weeks (n = 4), 180 mg + 1.4 mg/kg (n = 3), and 180 mg + 2.8 mg/kg (n = 11). Nausea, anorexia, fatigue, and mucositis were common but rarely reached ≥grade 3 severity. Myelosuppression was uncommon. ORR was 16.7% (3/18). An additional 3 pts had stable disease (of these 2 had stable disease for >18 weeks); CB18 was 27.8%. Median PFS was 2.0 months (95% confidence interval for PFS: 1.2-6.2). Pts with clinical benefit were enriched with genomic alterations in the PI3K and PTK7 pathways.

CONCLUSIONS

The combination of gedatolisib + cofetuzumab pelidotin was well tolerated and demonstrated promising clinical activity. Further investigation of this drug combination in metastatic TNBC is warranted.

Impact of African ancestry on the relationship between body mass index and survival in an early-stage breast cancer trial (ECOG-ACRIN E5103)

BACKGROUND

African ancestry (AA) and obesity are associated with worse survival in early-stage breast cancer. Obesity disproportionately affects women of AA; however, the intersection between ancestry and obesity on breast cancer outcomes remains unclear.

METHODS

A total of 2854 patients in the adjuvant trial E5103 were analyzed. Genetic ancestry was determined using principal components from a genome-wide array. The impact of continuous or binary body mass index (BMI) on disease-free survival (DFS) and overall survival (OS) was evaluated by multivariable Cox proportional hazards models in AA patients and European ancestry (EA) patients.

RESULTS

There were 2471 EA patients and 383 AA patients. Higher BMI was significantly associated with worse DFS and OS only in AA patients (DFS hazard ratio [HR], 1.25; 95% CI, 1.07-1.46; OS HR, 1.38; 95% CI, 1.10-1.73), not in EA patients (DFS HR, 0.97; 95% CI, 0.90-1.05; OS HR, 1.03; 95% CI, 0.93-1.14). Severe obesity (BMI ≥40) was significantly associated with worse survival in AA patients (DFS HR, 2.04; 95% CI, 1.21-3.43; OS HR, 2.21; 95% CI, 1.03-4.75) but had no impact on that of EA patients. In the estrogen receptor-positive (ER+) and triple-negative breast cancer subgroups, BMI was significantly associated with worse outcomes only in those AA patients with ER+ disease. Within the AA group, BMI remained associated with worse survival regardless of the AA proportion.

CONCLUSIONS

Higher BMI was statistically significantly associated with worse breast cancer outcomes in AA but not EA patients. This association was most significant for severe obesity and those with ER+ disease. These observations help define optimal populations for weight change interventions designed to affect disparities and survival in early-stage breast cancer.

LAY SUMMARY

African ancestry and obesity are both risk factors for worse survival after early-stage breast cancer. Women of African descent are also disproportionately affected by obesity; however, it is unclear what impact body weight has on racial disparities in breast cancer. Data from a large phase 3 clinical trial in high-risk, early-stage breast cancer were used to determine how body weight affects survival outcomes in European versus African Americans. Study results demonstrate that a higher body mass index is associated with increased risk of breast cancer recurrence and worse survival in women of African ancestry but not in women of European ancestry.

Association Between Surgery Preference and Receipt in Ductal Carcinoma In Situ After Breast Magnetic Resonance Imaging: An Ancillary Study of the ECOG-ACRIN Cancer Research Group (E4112)

Importance

Guiding treatment decisions for women with ductal carcinoma in situ (DCIS) requires understanding patient preferences and the influence of preoperative magnetic resonance imaging (MRI) and surgeon recommendation.

Objective

To identify factors associated with surgery preference and surgery receipt among a prospective cohort of women with newly diagnosed DCIS.

Design, Setting, and Participants

A prospective cohort study was conducted at 75 participating institutions, including community practices and academic centers, across the US between March 25, 2015, and April 27, 2016. Data were analyzed from August 2 to September 24, 2021. This was an ancillary study of the ECOG-ACRIN Cancer Research Group (E4112). Women with recently diagnosed unilateral DCIS who were eligible for wide local excision and had a diagnostic mammogram within 3 months of study registration were included. Participants who had documented surgery and completed the baseline patient-reported outcome questionnaires were included in this substudy.

Exposures

Women received preoperative MRI and surgeon consultation and then underwent wide local excision or mastectomy. Participants will be followed up for recurrence and overall survival for 10 years from the date of surgery.

Main Outcomes and Measures

Patient-reported outcome questionnaires assessed treatment goals and concerns and surgery preference before MRI and after MRI and surgeon consultation.

Results

Of the 368 participants enrolled 316 (86%) were included in this substudy (median [range] age, 59.5 [34-87] years; 45 women [14%] were Black; 245 [78%] were White; and 26 [8%] were of other race). Pre-MRI, age (odds ratio [OR] per 5-year increment, 0.45; 95% CI, 0.26-0.80; P = .007) and the importance of keeping one's breast (OR, 0.48; 95% CI, 0.31-0.72; P < .001) vs removal of the breast for peace of mind (OR, 1.35; 95% CI, 1.04-1.76; P = .03) were associated with surgery preference for mastectomy. After MRI and surgeon consultation, MRI upstaging (48 of 316 [15%]) was associated with patient preference for mastectomy (OR, 8.09; 95% CI, 2.51-26.06; P < .001). The 2 variables with the highest ORs for initial receipt of mastectomy were MRI upstaging (OR, 12.08; 95% CI, 4.34-33.61; P < .001) and surgeon recommendation (OR, 4.85; 95% CI, 1.99-11.83; P < .001).

Conclusions and Relevance

In this cohort study, change in patient preference for DCIS surgery and surgery received were responsive to MRI results and surgeon recommendation. These data highlight the importance of ensuring adequate information and ongoing communication about the clinical significance of MRI findings and the benefits and risks of available treatment options.

Abstract P4-10-02: Patient-reported outcomes in EA1131: A randomized phase III trial of platinum vs. capecitabine in patients with residual triple-negative breast cancer after neoadjuvant chemotherapy

Background: Understanding health-related quality of life (HRQOL), including side effects, is critical to guide supportive care during chemotherapy. The EA1131 trial demonstrated that Platinum (Plat) was unlikely to improve outcomes compared to capecitabine (Cape) in patients with stage II-III triple-negative breast cancer (TNBC) of basal subtype and ≥1 cm residual disease after neoadjuvant chemotherapy (NAC), supporting Cape as the continued standard of care. Patient-reported outcomes (PRO) were administered as a sub-study to understand HRQOL and symptoms from the patient’s perspective. Methods: EA1131 was amended in 9/2017 to add PRO endpoints and all patients enrolled after this amendment were eligible for the PRO sub-study. The Functional Assessment of Cancer Therapy-Breast Cancer Symptom Index (FBSI) and the Functional Assessment of Cancer Therapy/Gynecologic Oncology Group Neurotoxicity Subscale (NtxS; Plat arm only) were administered at baseline (BL), cycle 3 day 1 (C3D1), and following treatment at 6 and 15 months. Due to early trial termination, the PRO sub-study target accrual (n=362) was not reached. It was hypothesized that HRQOL, assessed by the FBSI-Treatment Side Effect (TSE) subscale (range 0-16, higher score = less side effects, better HRQOL), would indicate fewer post-treatment side effects at 6 and 15 months following Plat compared to Cape. The Wilcoxon rank sum test was used to compare FBSI-TSE subscale scores and total FBSI scores (range 0-64, higher score = better overall HRQOL) between arms at BL, C3D1, 6 months and 15 months. Two-sample t-tests were used to compare change in FBSI-TSE subscale scores and total FBSI scores from BL to C3D1 between arms. Change in NtxS scores (range 0-44, higher score = less neurotoxicity) from BL to C3D1 was evaluated with the paired t-test. Analyses were exploratory and p-values &lt;0.05 considered significant without multiple comparisons adjustment. Results: Of 331 patients eligible for the PRO sub-study (156 Plat arm, 175 Cape arm), 296 (89.4%) completed ≥1 PRO. Mean FBSI-TSE subscale scores were better for Cape at BL (Cape 14.5, Plat 13.9, p-value 0.02), for Plat at C3D1 (Cape 13.5, Plat 14.0, p-value 0.04), and did not differ at 6 months (Cape 14.6, Plat 14.7, p-value 0.70) or 15 months (Cape 14.9, Plat 14.5, p-value 0.44). FBSI-TSE subscale scores worsened from BL to C3D1 for Cape but not for Plat (mean change Cape -0.72, mean change Plat 0.15, p-value 0.003). FBSI-TSE subscale change scores from BL to C3D1 exceeded the threshold for clinically meaningful worsening (&gt; 1.5 points) in 27% of patients on Cape and 23% of patients on Plat (p-value 0.51). Mean total FBSI scores did not differ between arms at any time (BL: Cape 50.6, Plat 49.7; C3D1: Cape 48.1, Plat 48.0; 6 months: Cape 49.9, Plat 51.1; 15 months: Cape 53.3, Plat 50.3; all p &gt; 0.05). Mean change in total FBSI scores from BL to C3D1 did not differ between arms (Cape -2.20, Plat -1.83, p = 0.75). Mean (standard deviation) NtxS scores for the Plat arm were 38 (6.3), 36.1 (7.8), 36 (7.1) and 34.5 (7.9) at BL, C3D1, 6 months and 15 months, respectively. Mean NtxS score decreased (indicating worsening neurotoxicity) from BL to C3D1 (p-value 0.006). Conclusions: Despite more frequent severe toxicity by CTCAE criteria for Plat than Cape, patient-reported side effects worsened during treatment with Cape but not Plat. Overall, changes in HRQOL were small for both arms and resolved after therapy. However approximately one-fourth of patients had clinically meaningful worsening side effects on both arms. PRO-assessed neurotoxicity increased in the Plat arm. This PRO sub-study demonstrates that PROs capture toxicities beyond CTCAE criteria and provides novel data about patients’ experience during adjuvant chemotherapy following NAC for TNBC.

Citation Format: Karen L Smith, Fengmin Zhao, Ingrid A Mayer, Amye J Tevaarwerk, Sofia F Garcia, Carlos L Arteaga, William F Symmans, Ben H Park, Brian L Burnette, Della F Makower, Margaret Block, Kimberly A Morley, Chirag R Jani, Craig Mescher, Shabana J Dewani, Ursa Brown-Glaberman, Lisa E Flaum, Erica L Mayer, William M Sikov, Eve T Rodler, Angela M DeMichele, Joseph A Sparano, Antonio C Wolff, Kathy D Miller, Lynne I Wagner. Patient-reported outcomes in EA1131: A randomized phase III trial of platinum vs. capecitabine in patients with residual triple-negative breast cancer after neoadjuvant chemotherapy [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 P4-10-02.

Abstract PD9-10: BRE12-158: A post-neoadjuvant, randomized phase 2 trial of personalized therapy vs. treatment of physician’s choice for patients with residual triple negative breast cancer

Purpose: Patients with triple negative breast cancer (TNBC) with residual disease after neoadjuvant chemotherapy (NAC) have high risk of recurrence with prior data suggesting improved outcomes with capecitabine. Targeted agents have demonstrated activity across multiple cancer types. BRE12-158 was a phase 2, multicenter trial that randomized TNBC patients with residual disease after NAC to genomically-directed therapy vs. treatment of physician choice (TPC). Patients and Methods: From March 2014 to December 2018, 197 patients were enrolled. Residual tumors were sequenced using a next generation sequencing (NGS) test. A molecular tumor board adjudicated all results. Patients were randomized to 4 cycles of genomically-directed therapy (arm A) vs. TPC (arm B). Patients without a target were assigned to arm B. Primary endpoint was 2-year disease free survival (DFS) among randomized patients. Secondary/exploratory endpoints included: distant disease free survival (DDFS), overall survival (OS), toxicity assessment, time-based evolution of therapy, and drug-specific outcomes. Results: 193 patients were randomized or were assigned to arm B. The estimated 2-year DFS was 56.6% (95%CI:0.45-0.70) for arm A vs. 62.4% (95%CI:0.52-0.75) for randomized arm B. No difference was seen in DFS, DDFS, or OS for the entire or randomized populations. There was increased uptake of capecitabine for TPC over time. Patients randomized later had less distant recurrences. ctDNA status remained a significant predictor of outcome with some patients demonstrating clearance with post-neoadjuvant therapy. Conclusion: Genomically directed therapy was not superior to TPC for patients with residual TNBC after NAC. Capecitabine should remain the standard of care; however, the activity of other agents in this setting provides rationale for testing optimal combinations to improve outcomes for this high-risk population. ctDNA should be considered a standard covariate for trials in this setting.

Citation Format: Bryan P Schneider, Guanglong Jiang, Tarah J Ballinger, Fei Shen, Christopher Chitambar, Rita Nanda, Carla Falkson, Filipa C Lynce, Christopher Gallagher, Claudine Isaacs, Marcelo Blaya, Elisavet Paplomata, Radhika Walling, Karen Daily, Reshma Mahtani, Michael A Thompson, Robert Graham, Maureen E Cooper, Dean C Pavlick, Lee A Albacker, Jeffery Gregg, Jeffery P Solzak, Yu-Hsiang Chen, Casey L Bales, Erica Cantor, Bradley A Hancock, Nawal Kassem, Paul Helft, Bert O'Neil, Anna Maria Storniolo, Sunil Badve, Kathy D Miller, Milan Radovich. BRE12-158: A post-neoadjuvant, randomized phase 2 trial of personalized therapy vs. treatment of physician’s choice for patients with residual triple negative breast cancer [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 PD9-10.

Abstract P1-08-02: Cytochrome P450 reductase gene, POR, associated with paclitaxel induced peripheral neuropathy in patients of European ancestry from the adjuvant breast cancer trial, ECOG-ACRIN E5103

Introduction: Paclitaxel induced peripheral neuropathy (TIPN) is one of the most important survivorship issues of cancer patients with the potential to substantially impact quality of life. TIPN can lead to dose reductions, early cessation, and has the potential to compromise treatment efficacy. We previously reported both rare (SBF2) and common germline (FCAMR) predictors for TIPN in patients of African descent through whole-exome sequencing (WES) and a genome-wide association study (GWAS), respectively, in the adjuvant, randomized phase III breast cancer trial, E5103. These predictors are now being evaluated in the prospective ECOG-ACRIN trial EAZ171 (NCT04001829). We have also previously reported our evaluation of common germline variants for patients of European descent through GWAS in E5103 with validation in another adjuvant breast cancer trial, E1199. Herein, we evaluated for rare variants that were associated with risk of TIPN in patients of European ancestry from WES in E5103. Methods: Gene-based rare variant analyses using SKAT were performed to compare select cases of severe TIPN (n=172) and controls without any evidence of TIPN (n=170) derived from E5103. Cases were defined as those with at least grade 3 TIPN and controls were optimally. matched by demographic and risk factors and had no reported evidence for TIPN of any grade. Germline WES was conducted using Ion Proton™ Sequencers from Life Technologies with an average &gt;100X coverage of the exome. Rare variants with a minor allele frequency &lt;3% predicted to be deleterious by protein prediction programs were retained for the analysis. 7,278 genes passed quality control and were included in the analysis, setting the threshold for significance at a p-value &lt; 6.87 ×10-6 after Bonferroni correction. Results: Cytochrome P450 oxidoreductase (POR) was significantly associated with an increased risk of grade 3+ TIPN (p =1.82 ×10-6). Six variants predicted to be deleterious in POR were identified in the study population. Paclitaxel is predominately metabolized by cytochrome P450 (CYP) 2C8 and 3A4. A functional cytochrome P450 oxidoreductase is required for the catalytic activities of all 57 CYP family members to metabolize drugs, xenobiotics, and steroid hormones. Conclusion: Rare variants in cytochrome P450 oxidoreductase predicted an increased risk of severe TIPN in patients receiving paclitaxel. These rare variants in POR may modulate the catalytic activities of P450 enzymes that are responsible for paclitaxel metabolism and have a striking biological rationale as contributors to TIPN. Work is ongoing to validate these findings mechanistically and to identify strategies to nullify the impact of these deleterious variants.

Citation Format: Fei Shen, Guanglong Jiang, Laura Gardner, Gloria Xue, Santosh Philips, Reynold Ly, Osei Wilberforce, Xi Wu, Erica Cantor, Chau Dang, Donald Northfelt, Todd Skaar, Kathy D. Miller, George Sledge, Bryan P Schneider. Cytochrome P450 reductase gene, POR, associated with paclitaxel induced peripheral neuropathy in patients of European ancestry from the adjuvant breast cancer trial, ECOG-ACRIN E5103 [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 P1-08-02.

Treatment Exposure and Discontinuation in the PALbociclib CoLlaborative Adjuvant Study of Palbociclib With Adjuvant Endocrine Therapy for Hormone Receptor-Positive/Human Epidermal Growth Factor Receptor 2-Negative Early Breast Cancer (PALLAS/AFT-05/ABCSG-42/BIG-14-03)

PURPOSE

The PALLAS study investigated whether the addition of palbociclib, an oral CDK4/6 inhibitor, to adjuvant endocrine therapy (ET) improves invasive disease-free survival (iDFS) in early hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) breast cancer. In this analysis, we evaluated palbociclib exposure and discontinuation in PALLAS.

METHODS

Patients with stage II-III HR+, HER2- disease were randomly assigned to 2 years of palbociclib with adjuvant ET versus ET alone. The primary objective was to compare iDFS between arms. Continuous monitoring of toxicity, dose modifications, and early discontinuation was performed. Association of baseline covariates with time to palbociclib reduction and discontinuation was analyzed with multivariable competing risk models. Landmark and inverse probability weighted per-protocol analyses were performed to assess the impact of drug persistence and exposure on iDFS.

RESULTS

Of the 5,743 patient analysis population (2,840 initiating palbociclib), 1,199 (42.2%) stopped palbociclib before 2 years, the majority (772, 27.2%) for adverse effects, most commonly neutropenia and fatigue. Discontinuation of ET did not differ between arms. Discontinuations for non-protocol-defined reasons were greater in the first 3 months of palbociclib, and in the first calendar year of accrual, and declined over time. No significant relationship was seen between longer palbociclib duration or ≥ 70% exposure intensity and improved iDFS. In the weighted per-protocol analysis, no improvement in iDFS was observed in patients receiving palbociclib versus not (hazard ratio 0.89; 95% CI, 0.72 to 1.11).

CONCLUSION

Despite observed rates of discontinuation in PALLAS, analyses suggest that the lack of significant iDFS difference between arms was not directly related to inadequate palbociclib exposure. However, the discontinuation rate illustrates the challenge of introducing novel adjuvant treatments, and the need for interventions to improve persistence with oral cancer therapies.

Inflammatory cytokines and distant recurrence in HER2-negative early breast cancer

Systemic inflammation is believed to contribute to the distant recurrence of breast cancer. We evaluated serum samples obtained at diagnosis from 249 case:control pairs with stage II-III Her2-negative breast cancer with or without subsequent distant recurrence. Conditional logistic regression analysis, with models fit via maximum likelihood, were used to estimate hazard ratios (HRs) and test for associations of cytokines with distant recurrence risk. The only biomarker associated with a significantly increased distant recurrence risk when adjusted for multiple testing was the proinflammatory cytokine IL-6 (HR 1.37, 95% confidence intervals [CI] 1.15, 1.65, p = 0.0006). This prospective-retrospective study provides evidence indicating that higher levels of the cytokine IL-6 at diagnosis are associated with a significantly higher distant recurrence risk.

Quality of Life Following Receipt of Adjuvant Chemotherapy With and Without Bevacizumab in Patients With Lymph Node-Positive and High-Risk Lymph Node-Negative Breast Cancer

IMPORTANCE

Breast cancer treatment can impact not only short-term health but may also affect longer-term quality of life (QOL).

OBJECTIVE

To describe and evaluate factors associated with diminished QOL following completion of active treatment.

DESIGN, SETTING, AND PARTICIPANTS

This was a secondary analysis of a randomized clinical trial included patients with lymph node-positive or high-risk lymph node-negative breast cancer who had undergone definitive surgery and were enrolled in ECOG-ACRIN E5103, a multisite phase 3 trial. A survey was administered 18 months after enrollment to patients enrolled between January and June 2010. Final analysis of the data took place from March to December 2021.

INTERVENTIONS

Patients received adjuvant doxorubicin, cyclophosphamide, and paclitaxel with either bevacizumab or placebo.

MAIN OUTCOMES AND MEASURES

QOL and health status assessed with the EuroQol 5-Dimension 3-Levels (EQ-5D-3L), EQ-visual analog scale (EQ-VAS), and the Functional Assessment of Cancer Therapy-Breast Cancer, with arm subscale (FACT-B+4). Groups were compared by Fisher exact test, Wilcoxon rank sum, or Kruskal-Wallis test. Multivariable linear regression was used to assess factors independently associated with FACT-B scores.

RESULTS

Data at 18 months were available from 455 of 519 patients (87.7%) enrolled in the trial. Median (range) age at enrollment was 52 (25-76) years. No differences in QOL (median [range] FACT-B scores: group A, 123 [67-146]; group B, 114 [54-148]; group C, 117 [42-148]; P = .23) or health status (median [range] EQ-5D-3L index scores: group A, 0.83 [0.28-1.00]; group B, 0.83 [0.20-1.00]; group C, 0.83 [0.17-1.00], P = .80; median EQ-VAS: group A, 85 [20-100]; group B, 85 [0-100]; group C, 85 [0-100]; P = .79) were observed across treatment groups; results for subsequent analyses were therefore reported irrespective of primary treatment. Overall, half of patients (258 of 444 [58%]) reported at least some pain or discomfort; 170 (38%) reported symptoms of anxiety or depression. In multivariable analyses, mastectomy with radiation (vs breast conserving surgery) and Asian, Black, or American Indian or Alaska Native race (vs White race) were associated with lower QOL (mastectomy with radiation: coefficient: -5.5; 95% CI, -10.1 to -0.9; Asian, Black, or American Indian or Alaska Native race: coefficient: -7.3; 95% CI, -13.2, -1.4).

CONCLUSIONS AND RELEVANCE

In this study, the addition of bevacizumab to chemotherapy was not negatively associated with QOL at 18 months. A substantial proportion of participants reported problems related to pain or discomfort and anxiety or depression, demonstrating persistent consequences for physical and psychosocial well-being in this heavily treated population. Many problems reported are amenable to intervention, underscoring the need for timely referral to supportive resources, especially for women of color and those who have more extensive local therapy.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00433511.

Adjuvant Palbociclib for Early Breast Cancer: The PALLAS Trial Results (ABCSG-42/AFT-05/BIG-14-03)

PURPOSE

Palbociclib is a cyclin-dependent kinase 4 and 6 inhibitor approved for advanced breast cancer. In the adjuvant setting, the potential value of adding palbociclib to endocrine therapy for hormone receptor-positive breast cancer has not been confirmed.

PATIENTS AND METHODS

In the prospective, randomized, phase III PALLAS trial, patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative early breast cancer were randomly assigned to receive 2 years of palbociclib (125 mg orally once daily, days 1-21 of a 28-day cycle) with adjuvant endocrine therapy or adjuvant endocrine therapy alone (for at least 5 years). The primary end point of the study was invasive disease-free survival (iDFS); secondary end points were invasive breast cancer-free survival, distant recurrence-free survival, locoregional cancer-free survival, and overall survival.

RESULTS

Among 5,796 patients enrolled at 406 centers in 21 countries worldwide over 3 years, 5,761 were included in the intention-to-treat population. At the final protocol-defined analysis, at a median follow-up of 31 months, iDFS events occurred in 253 of 2,884 (8.8%) patients who received palbociclib plus endocrine therapy and in 263 of 2,877 (9.1%) patients who received endocrine therapy alone, with similar results between the two treatment groups (iDFS at 4 years: 84.2% v 84.5%; hazard ratio, 0.96; CI, 0.81 to 1.14; P = .65). No significant differences were observed for secondary time-to-event end points, and subgroup analyses did not show any differences by subgroup. There were no new safety signals for palbociclib in this trial.

CONCLUSION

At this final analysis of the PALLAS trial, the addition of adjuvant palbociclib to standard endocrine therapy did not improve outcomes over endocrine therapy alone in patients with early hormone receptor-positive breast cancer.

Inflammatory breast cancer defined: proposed common diagnostic criteria to guide treatment and research

Purpose

Inflammatory breast cancer is a deadly and aggressive type of breast cancer. A key challenge relates to the need for a more detailed, formal, objective definition of IBC, the lack of which compromises clinical care, hampers the conduct of clinical trials, and hinders the search for IBC-specific biomarkers and treatments because of the heterogeneity of patients considered to have IBC.

Methods

Susan G. Komen, the Inflammatory Breast Cancer Research Foundation, and the Milburn Foundation convened patient advocates, clinicians, and researchers to review the state of IBC and to propose initiatives to advance the field. After literature review of the defining clinical, pathologic, and imaging characteristics of IBC, the experts developed a novel quantitative scoring system for diagnosis.

Results

The experts identified through consensus several “defining characteristics” of IBC, including factors related to timing of onset and specific symptoms. These reflect common pathophysiologic changes, sometimes detectable on biopsy in the form of dermal lymphovascular tumor emboli and often reflected in imaging findings. Based on the importance and extent of these characteristics, the experts developed a scoring scale that yields a continuous score from 0 to 48 and proposed cut-points for categorization that can be tested in subsequent validation studies.

Conclusion

To move beyond subjective ‘clinical diagnosis’ of IBC, we propose a quantitative scoring system to define IBC, based on clinical, pathologic, and imaging features. This system is intended to predict outcome and biology, guide treatment decisions and inclusion in clinical trials, and increase diagnostic accuracy to aid basic research; future validation studies are necessary to evaluate its performance.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10549-021-06434-x.

Abstract PO-219: The implications of genetic ancestry and allostatic load on clinical outcomes in the ECOG-ACRIN adjuvant breast cancer trial E5103

Introduction: Elevated allostatic load (AL) has been associated with poor tumor prognostic features in Black breast cancer patients and worse disease specific and overall survival among cancer patients. To date, there are no studies evaluating the relationship between genetic ancestry, allostatic load and clinical trial endpoints such as completion of chemotherapy per protocol or overall survival. Prior evaluations of the ECOG-ACRIN adjuvant breast cancer trial E5103 suggests African ancestry is associated with a worse invasive disease-free survival and lower odds of chemotherapy completion. The objective of this study is to evaluate the association of genetic ancestry and AL with trial completion per protocol and with overall survival among patients in E5103. Methods: ECOG-ACRIN E5103 was a clinical trial that compared doxorubicin and cyclophosphamide (AC) for four cycles, followed by 12 weeks of weekly paclitaxel with placebo (Arm A) to the same chemotherapy with either concurrent bevacizumab (Arm B) or with concurrent plus sequential bevacizumab (Arm C) among women with node positive or high-risk node negative HER2 negative disease. Genetic ancestry groups of African ancestry (AA), European ancestry (EA) and other ancestry (OA) were determined using genome-wide single nucleotide polymorphisms. AL, at trial entry, was comprised of the biomarkers body mass index, systolic blood pressure, diastolic blood pressure, creatinine, IL6, IL10, and TNF alpha. To calculate AL, patients were awarded a point if their biomarker value was above the 75 percentile of the study sample. Logistic regression and Cox-Proportional Hazard models (odds ratio(OR) and hazard ratio (HR) estimates with corresponding 95% confidence intervals (CI)) were used to assess association with chemotherapy completion and with overall mortality. Estimates for AL were adjusted for genetic ancestry. Results: There were 348 patients in the study. The majority of the sample was of EA (EA 80%, AA 10%, OA 10%). Median (range) of AL was 2(0-6). Patients of AA (2.1(1.3)) and EA (1.88(1.4)) had a higher mean (SD) AL score compared to OA patients (0.91(1.1). On adjusted analysis, a 1 unit increased in AL was associated with a 15% reduction in the odds of completing chemotherapy per protocol (OR 0.85, 95% CI 0.72-0.99). Additionally, a 1 unit increase in AL was associated with a 14% increase in the hazard of death (HR 1.14, 95%CI 1.02-1.29). There was no association between ancestry and chemotherapy completion (AA OR 0.95, 95%CI 0.47-1.93; OA 1.82, 95%CI 0.78-4.23; ref EA) or survival (AA HR 1.40, 95% CI 0.85-2.31), OA 0.89 (0.46-1.73; ref EA). Moreover, there was no interaction between AL and ancestry. Conclusion: Among patients enrolled in E5103, AL appeared to be a better predictor of chemotherapy completion and overall survival than genetic ancestry. These results suggest life course exposure to chronic stress has implication in clinical outcomes even within the context of equivalent access to and quality of care.

Citation Format: Samilia Obeng-Gyasi, Anne ONeill, Kathy D. Miller, Bryan P. Schneider, Ann H. Patridge, Lava R. Timsina, George W. Sledge, Lynne Wagner, Ruth C. Carlos. The implications of genetic ancestry and allostatic load on clinical outcomes in the ECOG-ACRIN adjuvant breast cancer trial E5103 [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PO-219.

Tolerability of bevacizumab and chemotherapy in a phase 3 clinical trial with human epidermal growth factor receptor 2-negative breast cancer: A trajectory analysis of adverse events

BACKGROUND

E5103 was a study designed to evaluate the efficacy and safety of bevacizumab. It was a negative trial for the end points of invasive disease-free survival and overall survival. The current work examines the tolerability of bevacizumab and other medication exposures with respect to clinical outcomes and patient-reported outcomes (PROs).

METHODS

Adverse events (AEs) collected from the Common Terminology Criteria for Adverse Events were summarized to form an AE profile at each treatment cycle. All-grade and high-grade events were separately analyzed. The change in the AE profile over the treatment cycle was delineated as distinct AE trajectory clusters. AE-related and any-reason early treatment discontinuations were treated as clinical outcome measures. PROs were measured with the Functional Assessment of Cancer Therapy-Breast + Lymphedema. The relationships between the AE trajectory and early treatment discontinuation as well as PROs were analyzed.

RESULTS

More than half of all AEs (57.5%) were low-grade. A cluster of patients with broad and mixed AE (all-grade) trajectory grades was significantly associated with any-reason early treatment discontinuation (odds ratio [OR], 2.87; P = .01) as well as AE-related discontinuation (OR, 4.14; P = .001). This cluster had the highest count of all-grade AEs per cycle in comparison with other clusters. Another cluster of patients with primary neuropathic AEs in their trajectories had poorer physical well-being in comparison with a trajectory of no or few AEs (P < .01). A high-grade AE trajectory did not predict discontinuations.

CONCLUSIONS

A sustained and cumulative burden of across-the-board toxicities, which were not necessarily all recognized as high-grade AEs, contributed to early treatment discontinuation. Patients with neuropathic all-grade AEs may require additional attention for preventing deterioration in their physical well-being.

BRE12-158: A Postneoadjuvant, Randomized Phase II Trial of Personalized Therapy Versus Treatment of Physician's Choice for Patients With Residual Triple-Negative Breast Cancer

PURPOSE

Patients with triple-negative breast cancer (TNBC) with residual disease after neoadjuvant chemotherapy (NAC) have high risk of recurrence with prior data suggesting improved outcomes with capecitabine. Targeted agents have demonstrated activity across multiple cancer types. BRE12-158 was a phase II, multicenter trial that randomly allocated patients with TNBC with residual disease after NAC to genomically directed therapy versus treatment of physician choice (TPC).

PATIENTS AND METHODS

From March 2014 to December 2018, 193 patients were enrolled. Residual tumors were sequenced using a next-generation sequencing test. A molecular tumor board adjudicated all results. Patients were randomly allocated to four cycles of genomically directed therapy (arm A) versus TPC (arm B). Patients without a target were assigned to arm B. Primary end point was 2-year disease-free survival (DFS) among randomly assigned patients. Secondary/exploratory end points included distant disease-free survival, overall survival, toxicity assessment, time-based evolution of therapy, and drug-specific outcomes.

RESULTS

One hundred ninety-three patients were randomly allocated or were assigned to arm B. The estimated 2-year DFS for the randomized population only was 56.6% (95% CI, 0.45 to 0.70) for arm A versus 62.4% (95% CI, 0.52 to 0.75) for arm B. No difference was seen in DFS, distant disease-free survival, or overall survival for the entire or randomized populations. There was increased uptake of capecitabine for TPC over time. Patients randomly allocated later had less distant recurrences. Circulating tumor DNA status remained a significant predictor of outcome with some patients demonstrating clearance with postneoadjuvant therapy.

CONCLUSION

Genomically directed therapy was not superior to TPC for patients with residual TNBC after NAC. Capecitabine should remain the standard of care; however, the activity of other agents in this setting provides rationale for testing optimal combinations to improve outcomes. Circulating tumor DNA should be considered a standard covariate for trials in this setting.

Patient-Reported Testing Burden of Breast Magnetic Resonance Imaging Among Women With Ductal Carcinoma In Situ: An Ancillary Study of the ECOG-ACRIN Cancer Research Group (E4112)

IMPORTANCE

The use of magnetic resonance imaging (MRI) in pretreatment planning of ductal carcinoma in situ (DCIS) remains controversial. Understanding changes in short-term health-related quality of life associated with breast MRI would allow for a more complete comparative effectiveness assessment.

OBJECTIVE

To assess whether there are changes in patient-reported quality of life associated with breast MRI among women diagnosed with DCIS.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study was a substudy of a nonrandomized clinical trial conducted at 75 participating US institutions from March 2015 to April 2016. Women recently diagnosed with unilateral DCIS who were eligible for wide local excision and had a diagnostic mammogram within 3 months of study registration were included. A total of 355 women met the eligibility criteria and underwent the study MRI. Data analysis was performed from June 3, 2020, to July 1, 2021.

EXPOSURES

Participants underwent bilateral breast MRI within 30 days of study registration and before surgery. Information on patient-reported testing burden for breast MRI was collected after MRI and before surgery.

MAIN OUTCOMES AND MEASURES

The primary outcome of this substudy was the patient-reported testing burden of breast MRI, measured by the Testing Morbidities Index (TMI) summated scale score. The TMI is a 7-item instrument that evaluates the temporary changes in quality of life associated with imaging before, during, and after the test (0 represents the worst possible, 100 the hypothetical ideal test experience).

RESULTS

Of the 355 women who met the eligibility criteria, 244 (69%) completed both questionnaires and were included in this analysis. The median age was 59 years (range, 34-85 years). The mean MRI TMI summated scale score was 85.9 (95% CI, 84.6-87.3). Of the 244 women, 142 (58%) experienced at least some fear and anxiety before the examination, and 120 women (49%) experienced fear and anxiety during the examination. A total of 156 women (64%) experienced pain or discomfort during the examination. In multivariable analyses, greater test-related burden was associated with higher levels of cancer worry (regression coefficient, -2.75; SE, 0.94; P = .004).

CONCLUSIONS AND RELEVANCE

In this cohort study, a clinically meaningful breast MRI testing burden among women with DCIS was revealed that was significantly associated with cancer worry. Understanding the potential quality-of-life reduction associated with MRI, especially when used in combination with mammography, may allow development of targeted interventions to improve the patient experience.

A Multicenter Phase II Trial of Ipilimumab and Nivolumab in Unresectable or Metastatic Metaplastic Breast Cancer: Cohort 36 of Dual Anti-CTLA-4 and Anti-PD-1 Blockade in Rare Tumors (DART, SWOG S1609)

PURPOSE

Metaplastic breast cancer (MpBC) is a rare aggressive subtype that responds poorly to cytotoxics. Median survival is approximately eight months for metastatic disease. We report results for advanced MpBC treated with ipilimumab+nivolumab, a cohort of S1609 for rare cancers (DART: NCT02834013).

METHODS

Prospective, open-label, multicenter phase II (two-stage) trial of ipilimumab (1mg/kg IV q6weeks) plus nivolumab (240mg IV q2weeks) for advanced MpBC. Primary endpoint was objective response rate (ORR). Secondary endpoints included progression-free survival (PFS), overall survival (OS) and toxicity.

RESULTS

Overall, 17 evaluable patients enrolled. Median age was 60 years (26-85); median number of prior therapy lines, 2 (0-5). ORR was 18%; 3/17 patients achieved objective responses (1 complete, 2 partial responses) (2 spindle cell, 1 chondromyxoid histology), which are ongoing at 28+, 33+ and 34+ months, respectively. Median PFS and OS were 2 and 12 months, respectively. Altogether, 11 patients (65%) experienced adverse events (AEs), including one grade 5 AE. Eight patients (47%) developed an immune-related AE (irAE); with adrenal insufficiency observed in all three responders. Responses occurred in tumors with low tumor mutational burden, low PD-L1 and absent TILs.

CONCLUSION

The ipilimumab and nivolumab combination showed no new safety signals and met its primary endpoint with 18% ORR in advanced, chemotherapy-refractory MpBC. All responses are ongoing at >2 to almost 3 years later. The effect of ipilimumab and nivolumab was associated with exceptional responses in a subset of patients versus no activity. This combination warrants further investigation in MpBC, with special attention to understanding mechanism of action, and carefully designed to weigh against the significant risks of irAEs.

E2112: Randomized Phase III Trial of Endocrine Therapy Plus Entinostat or Placebo in Hormone Receptor-Positive Advanced Breast Cancer. A Trial of the ECOG-ACRIN Cancer Research Group

PURPOSE

Endocrine therapy resistance in advanced breast cancer remains a significant clinical problem that may be overcome with the use of histone deacetylase inhibitors such as entinostat. The ENCORE301 phase II study reported improvement in progression-free survival (PFS) and overall survival (OS) with the addition of entinostat to the steroidal aromatase inhibitor (AI) exemestane in advanced hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer.

PATIENTS AND METHODS

E2112 is a multicenter, randomized, double-blind, placebo-controlled phase III study that enrolled men or women with advanced HR-positive, HER2-negative breast cancer whose disease progressed after nonsteroidal AI. Participants were randomly assigned to exemestane 25 mg by mouth once daily and entinostat (EE) or placebo (EP) 5 mg by mouth once weekly. Primary end points were PFS by central review and OS. Secondary end points included safety, objective response rate, and lysine acetylation change in peripheral blood mononuclear cells between baseline and cycle 1 day 15.

RESULTS

Six hundred eight patients were randomly assigned during March 2014-October 2018. Median age was 63 years (range 29-91), 60% had visceral disease, and 84% had progressed after nonsteroidal AI in metastatic setting. Previous treatments included chemotherapy (60%), fulvestrant (30%), and cyclin-dependent kinase inhibitor (35%). Most common grade 3 and 4 adverse events in the EE arm included neutropenia (20%), hypophosphatemia (14%), anemia (8%), leukopenia (6%), fatigue (4%), diarrhea (4%), and thrombocytopenia (3%). Median PFS was 3.3 months (EE) versus 3.1 months (EP; hazard ratio = 0.87; 95% CI, 0.67 to 1.13; P = .30). Median OS was 23.4 months (EE) versus 21.7 months (EP; hazard ratio = 0.99; 95% CI, 0.82 to 1.21; P = .94). Objective response rate was 5.8% (EE) and 5.6% (EP). Pharmacodynamic analysis confirmed target inhibition in entinostat-treated patients.

CONCLUSION

The combination of exemestane and entinostat did not improve survival in AI-resistant advanced HR-positive, HER2-negative breast cancer.

Exercise load monitoring: integrated approaches to advance the individualisation of exercise oncology

Whether slowing disease progression or combatting the ills of advancing age, the extensive utility of exercise training has contributed to the outright declaration by the American College of Sports Medicine that 'exercise is medicine'. Consistent with general framework of adaptation, the advantages of exercise training are indiscriminate-benefitting even the most susceptible clinical populations. Still, the benefit of exercise training presupposes healthy adaptation wherein progressive overload matches sufficient recovery. Indeed, a difference exists between healthy adaptation and non-functional over-reaching (ie, when internal/external load exceeds recovery capacity)-a difference that may be blurred by cancer treatment and/or comorbidity. Recent advances in smartwatches make them ideally suited to non-invasively monitor the physiological stresses to exercise training. Resolving whether individuals are successfully adapting to exercise training via load monitoring bears clinical and practical relevance. While behaviour-change research aims to identify positive constructs of exercise adherence, further attention is needed to uncover how to optimise exercise prescription among cancer populations. Herein, we briefly discuss the constituents of exercise load monitoring, present examples of internal and external load and consider how such practices can be applied to cancer populations.

Inhibiting Fatty Acid Synthase with Omeprazole to Improve Efficacy of Neoadjuvant Chemotherapy in patients with Operable TNBC

PURPOSE

Fatty acid synthase (FASN) is overexpressed in 70% of operable triple negative breast cancer (TNBC) and is associated with poor prognosis. Proton pump inhibitors selectively inhibit FASN activity and induce apoptosis in TNBC cell lines.

EXPERIMENTAL DESIGN

Patients with operable TNBC were enrolled in this single arm Phase II study. Patients began omeprazole (OMP) 80 mg PO BID for 4-7 days prior to neoadjuvant anthracycline- taxane based chemotherapy (AC-T) and continued until surgery. The primary endpoint was pathologic complete response (pCR) in patients with baseline FASN overexpression (FASN+). Secondary endpoints included pCR in all surgery patients, change in FASN expression, enzyme activity, and downstream protein expression after OMP monotherapy; safety, and limited OMP pharmacokinetics.

RESULTS

Forty-two patients were recruited with a median age of 51y (28-72). Most patients had {greater than or equal to}cT2 (33, 79%) and {greater than or equal to}N1 (22, 52%) disease. FASN overexpression prior to AC-T was identified in 29/34 (85%) evaluable samples. The pCR rate was 72.4% (95% CI 52.8, 87.3) in FASN+ patients and 74.4% (95% CI 57.9, 87.0) in all surgery patients. Peak OMP concentration was significantly higher than the IC₅₀ for FASN inhibition observed in preclinical testing; FASN expression decreased with OMP monotherapy (mean change 0.12 (SD 0.25) ; p = 0.02). OMP was well tolerated with no {greater than or equal to} grade 3 toxicities.

CONCLUSIONS

FASN is commonly expressed in early TNBC. OMP can be safely administered in doses that inhibit FASN. The addition of OMP to neoadjuvant AC-T yields a promising pCR rate that needs further confirmation in randomized studies.

Preoperative Breast MRI for Newly Diagnosed Ductal Carcinoma in Situ: Imaging Features and Performance in a Multicenter Setting (ECOG-ACRIN E4112 Trial)

Background There are limited data from clinical trials describing preoperative MRI features and performance in the evaluation of mammographically detected ductal carcinoma in situ (DCIS). Purpose To report qualitative MRI features of DCIS, MRI performance in the identification of additional disease, and associations of imaging features with pathologic, genomic, and surgical outcomes from the Eastern Cooperative Oncology Group-American College of Radiology Imaging Network (ECOG-ACRIN) E4112 trial. Materials and Methods Secondary analyses of a multicenter prospective clinical trial from the ECOG-ACRIN Cancer Research Group included women with DCIS diagnosed with conventional imaging techniques (mammography and US), confirmed via core-needle biopsy (CNB), and enrolled between March 2015 and April 2016 who were candidates for wide local excision (WLE) based on conventional imaging and clinical examination results. DCIS MRI features and pathologic features from CNB and excision were recorded. Each woman without invasive upgrade of the index DCIS at WLE received a 12-gene DCIS score. MRI performance metrics were calculated. Associations of imaging features with invasive upgrade, dichotomized DCIS score (<39 vs ≥39), and single WLE success were estimated in uni- and multivariable analyses. Results Among 339 women (median age, 60 years; interquartile range, 51-66 years), most DCIS cases showed nonmass enhancement (NME) (195 of 339 [58%]) on MRI scans with larger median size than on mammograms (19 mm vs 12 mm; P < .001). Positive predictive value of MRI-prompted CNBs was 32% (21 of 66) (95% CI: 22, 44), yielding an additional cancer detection rate of 6.2% (21 of 339) (95% CI: 4.1, 9.3). MRI false-positive rate was 14.2% (45 of 318) (95% CI: 10.7, 18.4). No imaging features were associated with invasive upgrade or DCIS score (P = .05 to P = .95). Smaller size and focal NME distribution at MRI were linked to single WLE success (P < .001). Conclusion Preoperative MRI depicted ductal carcinoma in situ (DCIS) diagnosed with conventional imaging most commonly as nonmass enhancement, with larger median span than mammography, and additional cancer detection rate of 6.2%. MRI features of this subset of DCIS did not enable prediction of pathologic or genomic outcomes. Clinical trial registration no. NCT02352883 © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Kuhl in this issue.

Inflammatory breast cancer appearance at presentation is associated with overall survival

Background

Inflammatory breast cancer (IBC) is a clinical diagnosis. Here, we examined the association of a “classic” triad of clinical signs, swollen involved breast, nipple change, and diffuse skin change, with overall survival (OS).

Method

Breast medical photographs from patients enrolled on a prospective IBC registry were scored by two independent reviewers as classic (triad above), not classic, and difficult to assign. Chi‐squared test, Fisher's exact test, and Wilcoxon rank‐sum test were used to assess differences between patient groups. Kaplan–Meier estimates and the log‐rank test and Cox proportional hazard regression were used to assess the OS.

Results

We analyzed 245 IBC patients with median age 54 (range 26–81), M0 versus M1 status (157 and 88 patients, respectively). The classic triad was significantly associated with smoking, post‐menopausal status, and metastatic disease at presentation (p = 0.002, 0.013, and 0.035, respectively). Ten‐year actuarial OS for not classic and difficult to assign were not significantly different and were grouped for further analyses. Ten‐year OS was 29.7% among patients with the classic sign triad versus 57.2% for non‐classic (p < 0.0001). The multivariate Cox regression model adjusting for clinical staging (p < 0.0001) and TNBC status (<0.0001) demonstrated classic presentation score significantly associated with poorer OS time (HR 2.6, 95% CI 1.7–3.9, p < 0.0001).

Conclusions

A triad of classic IBC signs independently predicted OS in patients diagnosed with IBC. Further work is warranted to understand the biology related to clinical signs and further extend the understanding of physical examination findings in IBC.

Randomized Phase III Postoperative Trial of Platinum-Based Chemotherapy Versus Capecitabine in Patients With Residual Triple-Negative Breast Cancer Following Neoadjuvant Chemotherapy: ECOG-ACRIN EA1131

PURPOSE

Patients with triple-negative breast cancer (TNBC) and residual invasive disease (RD) after completion of neoadjuvant chemotherapy (NAC) have a high-risk for recurrence, which is reduced by adjuvant capecitabine. Preclinical models support the use of platinum agents in the TNBC basal subtype. The EA1131 trial hypothesized that invasive disease-free survival (iDFS) would not be inferior but improved in patients with basal subtype TNBC treated with adjuvant platinum compared with capecitabine.

PATIENTS AND METHODS

Patients with clinical stage II or III TNBC with ≥ 1 cm RD in the breast post-NAC were randomly assigned to receive platinum (carboplatin or cisplatin) once every 3 weeks for four cycles or capecitabine 14 out of 21 days every 3 weeks for six cycles. TNBC subtype (basal v nonbasal) was determined by PAM50 in the residual disease. A noninferiority design with superiority alternative was chosen, assuming a 4-year iDFS of 67% with capecitabine.

RESULTS

Four hundred ten of planned 775 participants were randomly assigned to platinum or capecitabine between 2015 and 2021. After median follow-up of 20 months and 120 iDFS events (61% of full information) in the 308 (78%) patients with basal subtype TNBC, the 3-year iDFS for platinum was 42% (95% CI, 30 to 53) versus 49% (95% CI, 39 to 59) for capecitabine. Grade 3 and 4 toxicities were more common with platinum agents. The Data and Safety Monitoring Committee recommended stopping the trial as it was unlikely that further follow-up would show noninferiority or superiority of platinum.

CONCLUSION

Platinum agents do not improve outcomes in patients with basal subtype TNBC RD post-NAC and are associated with more severe toxicity when compared with capecitabine. Participants had a lower than expected 3-year iDFS regardless of study treatment, highlighting the need for better therapies in this high-risk population.

Multi-center randomized study of pembrolizumab/carboplatin versus carboplatin alone in patients with chest wall disease from breast cancer: TBCRC 044

TPS1111

Background: Chest wall recurrence is a subtype of breast cancer that is challenging to treat, and associated with a short duration of response to treatment and an increased risk of development of distant metastases. Given the inflammatory nature of this disease and the association of chest wall disease with lymphovascular invasion, which is correlated with higher programmed cell death 1 (PD-1) expression, we hypothesized that immunotherapy may be beneficial as treatment. Combinations of immunotherapy and chemotherapy have a synergistic effect and demonstrated efficacy in the treatment of metastatic triple negative breast cancer (TNBC). This study is evaluating the efficacy of pembrolizumab, an anti-PD-1 antibody, in combination with carboplatin, in patients with chest wall infiltration from breast cancer. This drug combination has shown efficacy in advanced lung cancer. Methods: This is a multicenter, 2:1 randomized phase II study of pembrolizumab/carboplatin (Arm A, 56 patients) vs. carboplatin (Arm B, 28 patients) in 84 patients with chest wall disease from breast cancer, with or without distant metastases. Patients may have TNBC, hormone receptor positive/HER2 negative (following receipt of 2 prior hormone therapies), or HER2 positive breast cancer (with option to continue trastuzumab on study). Pembrolizumab is administered as 200 mg IV every 3 weeks, and carboplatin as AUC 5 IV every 3 weeks. Patients on Arm A may continue pembrolizumab +/- carboplatin (Arm Ax) after completion of 6 cycles of treatment, while patients in Arm B can cross-over to pembrolizumab (+/- carboplatin) on progression (Arm Bx). Patients must have adequate organ function, performance status ≤ 2, and may have received any number of lines of prior chemotherapy. Patients undergo serial chest wall photography and imaging (CT chest, abdomen, and pelvis, and bone scan) at baseline and every 6 weeks, as well as blood collection for correlative studies and chest wall biopsies at baseline and after 2 cycles of treatment. The primary endpoint is disease control rate (RECIST 1.1) at 18 weeks of treatment, and the study is powered to determine a 20% difference in disease control rates between arms (HR 0.52, a = 0.10, ß = 0.20). An interim analysis will occur for Arm B after 18 patients are enrolled, with a stopping rule for futility. Secondary endpoints include progression-free survival, toxicity (NCI CTCAE), and response based on irRECIST and tumor programmed death ligand 1 (PD-L1) expression. Exploratory objectives include evaluating changes in soluble PD-L1, tumor and peripheral blood immune composition, circulating tumor cells and cell-free DNA, and MYC oncogene expression. This study (NCT03095352) is open at 7 sites in the Translational Breast Cancer Research Consortium (TBCRC). 52 patients are enrolled. Grant funding is provided by Merck and UCSF. Clinical trial information: NCT03095352 .

Trial in progress: A phase 1, multicenter, open-label, dose-exploration and dose-expansion study evaluating the safety, tolerability, pharmacokinetics, and efficacy of AMG650 in subjects with advanced solid tumors

TPS5600

Background: KIF18A is a mitotic kinesin motor protein that regulates chromosome positioning during cell division and is overexpressed in a subset of human cancers. TP53 mutant unstable aneuploid cancer cells with chromosomal instability (CIN) features are dependent on KIF18A motor activity to prevent lethal multipolar cell division. Preclinical data demonstrate that treatment with AMG 650; an oral, first in class, selective small molecule inhibitor of KIF18A may be safe and tolerable. We are conducting a first-in-human phase 1 study with AMG 650 in adult subjects with locally advanced or metastatic solid tumors with TP53MUT, triple negative breast cancer (TNBC), high grade serous ovarian cancer (HGSOC) or serous like endometrial cancers and other solid tumors. Methods: In this phase 1, multicentric, dose escalation and dose expansion study we evaluate the safety and tolerability of AMG 650 monotherapy in patients with advanced/metastatic solid tumors (NCT04293094). The main objective is to determine the maximum tolerated dose (MTD) and/or recommended phase 2 dose (RP2D) based on emerging safety, efficacy, and pharmacodynamics (PD) data prior to reaching the MTD. Key inclusion criteria include the presence of measurable disease and diagnosis of advanced/metastatic triple negative breast cancer (TNBC), high-grade serous ovarian cancer (HGSOC), serous-like endometrial cancer or other solid tumors with documented TP53 mutations. In the dose expansion phase, participants with locally advanced or metastatic TNBC or HGSOC will be treated with the preliminary RP2D identified from the dose exploration part of the study. Primary endpoints include the incidence of Dose Limiting Toxicities (DLTs),Treatment-Emergent Adverse Events (TEAEs), Serious Adverse Events (SAEs), Treatment-related Adverse Events and the evaluation of the number of participants who experience a clinically significant change from baseline in vital signs, electrocardiogram and laboratory tests parameters. Secondary endpoints include Objective Response Rate, Duration of Response, Progression-free Survival, Clinical Benefit Rate, Time to Response, Time to Progression, Overall Survival (OS), Maximum Plasma Concentration (Cmax) of AMG 650, Time to Maximum Plasma Concentration (Tmax) of AMG 650 as well as Area Under the Plasma Concentration-time Curve (AUC) Over the Dosing Interval for AMG 650. Continuous monitoring of toxicity is conducted. The study began enrolling pts in March 2020 and is ongoing. For more information, please contact Amgen Medical Information: medinfo@amgen.com Clinical trial information: NCT04293094.

A Personalized, Dynamic Physical Activity Intervention Is Feasible and Improves Energetic Capacity, Energy Expenditure, and Quality of Life in Breast Cancer Survivors

Purpose

Despite survival and quality of life benefits associated with physical activity, many breast cancer survivors remain inactive. Effective, sustainable interventions must account for individual differences in capability, motivation, and environment. Here, we evaluate the feasibility, mechanics, and efficacy of delivering an individualized, dynamic intervention to increase energetic capacity and energy expenditure.

Methods

Stage 0–III breast cancer patients who had completed primary treatment were enrolled. Prior to the intervention, detailed movement data was collected with a wearable GPS and accelerometer for 3 weeks to establish baseline activity. Movement data was collected continuously throughout the 12-week intervention, during which patients received electronically delivered, tailored, dynamic activity “prescriptions”, adjusted based on demonstrated individual capability, daily movement in their environment, and progress.

Results

Of 66 enrolled, 57 participants began and completed the intervention. The intervention resulted in significant improvements in average steps (+558 steps/day, p = 0.01), energetic capacity measured by power generation on a stationary bicycle (1.76 to 1.99 W/kg lean mass, p < 0.01), and quality of life (FACT-B TOI, 72.8 to 74.8, p = 0.02). The greatest improvement in functional energetic capacity was seen in the lowest performing tertile at baseline (0.76 to 1.12 W/kg, p < 0.01).

Discussion

Wearable technology delivery of personalized activity prescriptions based on individual capability and movement behaviors demonstrates feasibility and early effectiveness. The high variability seen in baseline activity and function, as well as in response to the intervention, supports the need for future work in precision approaches to physical activity (NCT03158519).