Early Local Therapy for the Primary Site in De Novo Stage IV Breast Cancer: Results of a Randomized Clinical Trial (EA2108)

PURPOSE

Distant metastases are present in 6% or more of patients with newly diagnosed breast cancer. In this context, locoregional therapy for the intact primary tumor has been hypothesized to improve overall survival (OS), but clinical trials have reported conflicting results.

METHODS

Women presenting with metastatic breast cancer and an intact primary tumor received systemic therapy for 4-8 months; if no disease progression occurred, they were randomly assigned to locoregional therapy for the primary site (surgery and radiotherapy per standards for nonmetastatic disease) or continuing sysmetic therapy. The primary end point was OS; locoregional control and quality of life were secondary end points. The trial design provided 85% power to detect a 19.3% absolute difference in the 3-year OS rate in randomly assigned patients. The stratified log-rank test and Cox proportional hazards model were used to compare OS between arms. Cumulative incidence of locoregional progression was compared using Gray's test. Quality-of-life assessment used standard instruments.

RESULTS

Of 390 participants enrolled, 256 were randomly assigned: 131 to continued systemic therapy and 125 to early locoregional therapy. The 3-year OS was 67.9% without and 68.4% with early locoregional therapy (hazard ratio = 1.11; 90% CI, 0.82 to 1.52; P = .57). The median OS was 53.1 months (95% CI, 47.9 to not estimable) in the systemic therapy arm and 54.9 months (95% CI, 46.7 to not estimable) in the locoregional therapy arm. Locoregional progression was less frequent in those randomly assigned to locoregional therapy (3-year rate: 16.3% v 39.8%; P < .001). Quality-of-life measures were largely similar between arms.

CONCLUSION

Early locoregional therapy for the primary site did not improve survival in patients presenting with metastatic breast cancer. Although it was associated with improved locoregional control, this had no overall impact on quality of life.

Abstract PD9-01: Expanding downstaging criteria in AJCC pathologic prognostic staging using OncotypeDx Recurrence Score® assay in T1-2N0 hormone-receptor positive patients enrolled in the TAILORx trial

Background: The AJCC 8th edition pathologic prognostic staging (PPS) system, which incorporates both anatomic and biologic factors, was developed using data from patients captured in the National Cancer Database diagnosed 2010-2012 in whom complete anatomic (T, N and M category) as well as biologic data (grade, ER, PR, HER2) were available. The clinical endpoint was 3-year overall survival. In addition, the use of genomic assays was incorporated based on the initial report from the TAILORx trial, with patients with T1-2N0 hormone-receptor positive, HER2 negative (HR+,HER2-) breast cancer and an Oncotype DX Recurrence Score® (RS) result &lt;11 being staged as PPS IA. Given availability of long-term prospective followup data from TAILORx, we undertook this study to examine if the RS criteria for downstaging to PPS IA can be expanded using the patients enrolled on this trial. Methods: TAILORx assigned T1-2N0 HR+HER2- breast cancer patients with RS &lt;11 to endocrine therapy (ET) alone and RS &gt;25 to chemotherapy followed by ET (CET). Those with RS 11-25 were randomized to ET or CET. 10,273 patients were enrolled. Patients with incomplete HR status or grade and those with T3 disease were excluded for this analysis. Recurrence-free survival (RFS) in patients with RS &lt;11 were compared between patients that did and did not fall into current AJCC PPS IA category using the Kaplan-Meier method. Results: 9,535 patients were included for analysis. The majority were &gt; 50 years old (n=6893, 72.3%), had T1 tumors (n=6561, 68.8%), grade 2 disease (n=5291, 55.5%), and underwent lumpectomy (n=6855, 71.9%). RS breakdown was &lt;11 in 1539 (16.1%), 11-17 in 3423 (35.9%), 18-25 in 3088 (32.4%) and &gt;25 in 1485 (15.6%). 8,698 (91.2%) patients were AJCC PPS IA (including all T1N0 patients regardless of RS), and 837 (8.8%) were not PPS IA. Median follow-up time was 95 months. PPS IA patients had 8-yr RFS of 94.2% which was statistically similar to patients with RS 11-17 that were not PPS IA (91.7%, p=0.07) and better than patients with RS &gt;18 that were not PPS IA (85.4% for RS 18-25, 76.0% for RS &gt;25, p&lt;0.01). For patients with a RS 11-17 that were not PPS IA receiving ET alone, 8-yr RFS was 93.3% which was statistically similar to PPS IA patients receiving ET alone (94.9%, p=0.24). There was no RFS benefit with CET for patients with RS 11-17 not PPS IA (Table). Conclusions: Patients with T1-2N0 HR+HER2- breast cancer and RS&lt;18 have similar RFS to patients staged as PPS IA by the current AJCC staging system, regardless of treatment, suggesting that consideration could be given to expanding the criteria for pathologic prognostic stage IA to include RS&lt;18.

Comparison of RFS in patients with Stage IA and not Stage IA by AJCC PPS, n=9535Stage IANot stage IA, RS 11-17Not stage IA, RS 18-25Not stage IA, RS &gt;25All Patients, n=9535n=8698n=169n=269n=3998yr RFS % (95% CI)94.2 (93.6-94.8)91.7 (87.0-96.4)85.4 (80.3-90.5)76.0 (69.1-82.9)P-value*Ref0.07&lt;0.01&lt;0.01ET, n=5370n=5123n=88n=135n=248yr RFS % (95% CI)94.9 (94.1-95.7)93.3 (87.6-99.9)85.1 (77.8-92.4)58.3 (77.8-92.4)P-value*Ref0.24&lt;0.01&lt;0.01CET, n=4165n=3575n=81n=134n=3758yr RFS % (95% CI)93.2 (92.2-94.2)90.0 (82.4-97.6)85.8 (78.7-92.9)76.9 (69.8-84.0)P-value*Ref0.019&lt;0.01&lt;0.01ET endocrine therapy; CET chemoendocrine therapy*compared to T1-2N0 patients with PPS IA

Citation Format: Olga Kantor, Harold J Burstein, Tari King, Steven Shak, Christy Russell, Armando E Giuliano, Gabriel N Hortobagyi, Eric P Winer, Larissa A Korde, Joseph A Sparano, Elizabeth A Mittendorf. Expanding downstaging criteria in AJCC pathologic prognostic staging using OncotypeDx Recurrence Score® assay in T1-2N0 hormone-receptor positive patients enrolled in the TAILORx trial [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 PD9-01.

Abstract P1-08-35: Stromal tumor infiltrating lymphocytes analysis by race and ethnicity in triple negative breast cancers from 2 phase III randomized adjuvant breast cancer trials: ECOG-ACRIN E2197 and E1199

Background: Black patients with triple negative breast cancer (TNBC) have worse survival outcomes, even after adjusting for stage at diagnosis, income, insurance status and other socioeconomic factors. Little is known regarding anti-tumor immune responses in Black patients and how these differences affect responses to treatment in TNBC. Limited data exists regarding the stromal tumor infiltrating lymphocytes (sTILs, which are strongly prognostic in TNBC) distribution based on race and ethnicity. Here we evaluate the prevalence, distribution, and prognostic impact of sTILs in TNBC by race/ethnicity from 2 prospective clinical trials of adjuvant anthracycline/taxane-based chemotherapy (E2197 and E1199). Methods: Full-face hematoxylin and eosin-stained sections of 481 tumors from ECOG-ACRIN trials E2197 and E1199 were previously evaluated for density of sTILs and shown to be associated with disease-free survival (DFS), distant recurrence-free interval (DRFI), and overall survival (OS) (Adams, et al JCO 2014). Further analyses were undertaken to evaluate the impact of race/ethnicity. Results: The majority of the 481 TNBC were from White patients (82.3%, n=403); with 12.3% (n=59) Black patients, 1.6% (n=14) other (9 Hispanic, 3 Asian, 2 Other), and 0.5% (n=5) unknown race. Age distribution (mean 49.2 for White and 49.2 for Black) and node negative disease (White 68/403 (42%), Black 24/59 (41%)) were similar. However, tumor size ≤2cm was seen more commonly in White patients (34%, 137/403) compared with Black patients (20%, 12/59). Black patients had a higher proportion of high sTILs (≥30%) with 23.7% (14/59) compared to White patients (11.4%, 46/403). The association of continuous stromal TILs with DFS (hazard ratio for a 10-point difference) was 0.84 (95% CI 0.72, 0.98) for White patients and 0.94 (95% CI 0.73, 1.20) for Black patients [159 DFS events for Whites, 26 DFS events for Blacks]. Conclusions: This is the first dataset from prospective clinical trials evaluating sTILs in TNBC in Black patients. Prevalence of high sTILs was greater in Black patients compared to White patients. The association between increasing sTILs and improved invasive disease-free survival across racial/ethnic groups must be investigated in larger datasets.

Table 1.Race/EthnicityTotal (n=481)White (n=403)Black (n=59)Other (n=19)Mean age49.049.249.245.6T1 (tumor &lt;=2cm)157(32.6%)137 (34.0%)12 (20.3%)8 (42.1%)T2 (tumor &gt;2 and &lt;=5cm)283(58.8%)232 (57.6%)41 (69.5%)10 (52.6%)T3 and T441 (8.5%)34 (8.4%)6 (10.2%)1 (5.3%)Node negative197 (41.0%)168 (41.7%)24 (40.7%)5 (26.3%)Median sTILs (Quartiles)10 (10, 20)10 (10, 20)10 (10,20)20 (10, 30)sTILs = 095 (19.8%)83 (20.6%)10 (16.9%)2 (10.5%)sTILs 10-29%319 (66.3%)274 (68.0%)35 (59.3%)10 (52.6%)sTILs ≥30%67 (13.9%)46 (11.4%)14 (23.7%)7 (36.8%)—sTIL 30-49%,46 (9.6%)32 (7.9%)11 (18.6%)3 (15.8%)—sTIL 50-74%,17 (3.5%)11 (2.7%)3 (5.1%)3 (15.8%)—sTIL 75-100%4 (0.8%)3 (0.7%)01 (5.2%)iDFS (HR for 10% sTIL increase)0.86 (95% CI 0.76, 0.98)0.84 (95% CI 0.72, 0.98)0.94 (95% CI 0.73, 1.20)0.97 (95% CI 0.68, 1.40)DRFI (HR for 10% sTIL increase)0.82 (95% CI 0.68, 0.99)0.79 (95% CI 0.63, 1.00)1.08 (95% CI 0.82, 1.44)0.54 (95% CI 0.32, 0.90)OS (HR for 10% sTIL increase)0.81 (95% CI 0.69, 0.95)0.76 (95% CI 0.62, 0.94)1.01 (95% CI 0.76, 1.35)0.83 (95% CI 0.54, 1.29)

Citation Format: Natalie Klar, Robert J Gray, Sylvia Adams, Joseph A Sparano, Lori J Goldstein, Angela M DeMichele, Antonio C Wolff, Nancy E Davidson, George W Sledge, Sunil S Badve. Stromal tumor infiltrating lymphocytes analysis by race and ethnicity in triple negative breast cancers from 2 phase III randomized adjuvant breast cancer trials: ECOG-ACRIN E2197 and E1199 [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 P1-08-35.

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.

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.

Fatigue and endocrine symptoms among women with early breast cancer randomized to endocrine versus chemoendocrine therapy: Results from the TAILORx patient-reported outcomes substudy

BACKGROUND

TAILORx (Trial Assigning Individualized Options for Treatment) prospectively assessed fatigue and endocrine symptoms among women with early-stage hormone receptor-positive breast cancer and a midrange risk of recurrence who were randomized to endocrine therapy (E) or chemotherapy followed by endocrine therapy (CT+E).

METHODS

Participants completed the Functional Assessment of Chronic Illness Therapy-Fatigue, the Patient-Reported Outcomes Measurement Information System-Fatigue Short Form, and the Functional Assessment of Cancer Therapy-Endocrine Symptoms at the baseline and at 3, 6, 12, 24, and 36 months. Linear regression was used to model outcomes on baseline symptoms, treatment, and other factors.

RESULTS

Participants (n = 458) in both treatment arms reported greater fatigue and endocrine symptoms at early follow-up in comparison with the baseline. The magnitude of change in fatigue was significantly greater for the CT+E arm than the E arm at 3 and 6 months but not at 12, 24, or 36 months. The CT+E arm reported significantly greater changes in endocrine symptoms from the baseline to 3 months in comparison with the E arm; change scores were not significantly different at later time points. Endocrine symptom trajectories by treatment differed by menopausal status, with the effect larger and increasing for postmenopausal patients.

CONCLUSIONS

Adjuvant CT+E was associated with greater increases in fatigue and endocrine symptoms at early time points in comparison with E. These differences lessened over time, and this demonstrated early chemotherapy effects more than long-term ones. Treatment arm differences in endocrine symptoms were more evident in postmenopausal patients.

LAY SUMMARY

Participants in TAILORx (Trial Assigning Individualized Options for Treatment) with early-stage hormone receptor-positive breast cancer and an intermediate risk of recurrence were randomly assigned to endocrine or chemoendocrine therapy. Four hundred fifty-eight women reported fatigue and endocrine symptoms at the baseline and at 3, 6, 12, 24, and 36 months. Both groups reported greater symptoms at early follow-up versus the baseline. Increases in fatigue were greater for the chemoendocrine group than the endocrine group at 3 and 6 months but not later. The chemoendocrine group reported greater changes in endocrine symptoms in comparison with the endocrine group at 3 months but not later.

The 21-gene recurrence score in early non-ductal breast cancer: a National Cancer Database analysis

The 21-gene recurrence score (RS) is prognostic for recurrence and predictive of chemotherapy benefit in early estrogen receptor-positive (ER +) HER2-negative (HER2-) breast cancer (BCA). We evaluated clinicopathologic characteristics, RS and chemotherapy benefit in invasive ductal carcinoma (IDC), invasive lobular carcinoma (ILC), and carcinomas of mixed histologies (ductal + lobular (DLC), ductal + other (DOC), lobular + other (LOC)). Women diagnosed between 1/1/2010 and 1/1/2014 with ER + HER2- BCA, measuring <5 cm, with 0–3 involved axillary nodes, surgery as first treatment, and available RS, were identified from the NCDB. Associations between categorical variables were examined using chi-square test. Cox proportional hazards model was used to examine overall survival (OS) differences among histology subtypes. IDC was associated with smaller size, high grade, and RS > 26. ILC was associated with larger size, and least likely to be high grade (p < 0.0001). Lobular histology was associated with lower incidence of RS > 26. IDC patients (pts) were more likely to receive chemotherapy than pts with other histologies (p < 0.0001). OS for IDC, ILC and DOC were similar. DLC was associated with improved OS (HR 0.82, p = 0.02). Adjuvant chemotherapy was associated with improved OS in IDC (HR = 0.76, p < 0.0001) but not in ILC (HR = 0.99, p = 0.93), DLC (HR = 1.04, p = 0.86), DOC (HR = 0.87, p = 0.71), or LOC (HR = 2.91, p = 0.10). Lobular and mixed BCA histologies have distinct clinicopathologic features compared with IDC, and are less likely to have high RS. OS is similar for IDC and ILC. Although chemotherapy benefit was seen only in IDC, benefit for ILC with RS > 26 cannot be excluded.

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.

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.

Molecular markers of risk of subsequent invasive breast cancer in women with ductal carcinoma in situ: protocol for a population-based cohort study

INTRODUCTION

Ductal carcinoma in situ (DCIS) of the breast is a non-obligate precursor of invasive breast cancer (IBC). Many DCIS patients are either undertreated or overtreated. The overarching goal of the study described here is to facilitate detection of patients with DCIS at risk of IBC development. Here, we propose to use risk factor data and formalin-fixed paraffin-embedded (FFPE) DCIS tissue from a large, ethnically diverse, population-based cohort of 8175 women with a first diagnosis of DCIS and followed for subsequent IBC to: identify/validate miRNA expression changes in DCIS tissue associated with risk of subsequent IBC; evaluate ipsilateral IBC risk in association with two previously identified marker sets (triple immunopositivity for p16, COX-2, Ki67; Oncotype DX Breast DCIS score); examine the association of risk factor data with IBC risk.

METHODS AND ANALYSIS

We are conducting a series of case-control studies nested within the cohort. Cases are women with DCIS who developed subsequent IBC; controls (2/case) are matched to cases on calendar year of and age at DCIS diagnosis. We project 485 cases/970 controls in the aim focused on risk factors. We estimate obtaining FFPE tissue for 320 cases/640 controls for the aim focused on miRNAs; of these, 173 cases/346 controls will be included in the aim focused on p16, COX-2 and Ki67 immunopositivity, and of the latter, 156 case-control pairs will be included in the aim focused on the Oncotype DX Breast DCIS score®. Multivariate conditional logistic regression will be used for statistical analyses.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the Institutional Review Boards of Albert Einstein College of Medicine (IRB 2014-3611), Kaiser Permanente Colorado, Kaiser Permanente Hawaii, Henry Ford Health System, Mayo Clinic, Marshfield Clinic Research Institute and Hackensack Meridian Health, and from Lifespan Research Protection Office. The study results will be presented at meetings and published in peer-reviewed journals.

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.

The clinical utility of gene expression assays in breast cancer patients with 0-3 involved lymph nodes

Multigene expression assays are prognostic for recurrence in hormone-receptor positive 2 (HER-2) negative breast cancer, and, in some cases, predictive of benefit from chemotherapy or extended endocrine therapy. The results of these assays may be used to guide treatment recommendations for early HER-2 negative breast cancer. We review the results of trials establishing the clinical utility of several commercially available gene expression assays.

Immune Activation and Microbial Translocation as Prognostic Biomarkers for AIDS-Related Non-Hodgkin Lymphoma in the AMC-034 Study

PURPOSE

AIDS-related non-Hodgkin lymphoma (ARL) is the most common cancer in HIV-infected individuals in the United States and other countries in which HIV-positive persons have access to effective combination antiretroviral therapy (cART). Our prior work showed that pretreatment/postdiagnosis plasma levels of some cytokines, such as IL6, IL10, and CXCL13, have the potential to serve as indicators of clinical response to treatment and survival in ARL. The aims of this study were to identify novel prognostic biomarkers for response to treatment and/or survival in persons with ARL, including biomarkers of microbial translocation and inflammation.

EXPERIMENTAL DESIGN

We quantified plasma levels of several biomarkers (sCD14, LBP, FABP2, EndoCab IgM, IL18, CCL2/MCP-1, sCD163, IP-10/CXCL10, TARC/CCL17, TNFα, BAFF/BLyS, sTNFRII, sCD44, and sIL2Rα/sCD25) by multiplexed immunometric assays (Luminex) or ELISA in plasma specimens obtained from ARL patients enrolled in the AMC-034 trial, which compared infusional combination chemotherapy (EPOCH: etoposide, vincristine, doxorubicin, cyclophosphamide, and prednisone) with concurrent or sequential rituximab. Plasma was collected prior to the initiation of therapy (n = 57) and after treatment initiation (n = 55).

RESULTS

We found that several biomarkers decreased significantly after treatment, including TNFα, sCD25, LBP, and TARC (CCL17). Moreover, pretreatment plasma levels of BAFF, sCD14, sTNFRII, and CCL2/MCP-1 were univariately associated with overall survival, and pretreatment levels of BAFF, sTNFRII, and CCL2/MCP-1 were also associated with progression-free survival.

CONCLUSIONS

Our results suggest that patients with ARL who responded to therapy had lower pretreatment levels of inflammation and microbial translocation as compared with those who did not respond optimally.

Breast cancer survivorship care during the COVID-19 pandemic within an urban New York Hospital System

Purpose

To examine clinicodemographic determinants associated with breast cancer survivorship follow-up during COVID-19.

Methods

We performed a retrospective, population-based cohort study including early stage (Stage I-II) breast cancer patients who underwent resection between 2006 and 2018 in a New York City hospital system. The primary outcome was oncologic follow-up prior to and during the COVID-19 pandemic. Secondary analyses compared differences in follow-up by COVID-19 case rates stratified by ZIP code.

Results

A total of 2942 patients with early-stage breast cancer were available for analysis. 1588 (54%) of patients had attended follow-up in the year prior to the COVID-19 period but failed to continue to follow-up during the pandemic, either in-person or via telemedicine. 1242 (42%) patients attended a follow-up appointment during the COVID-19 pandemic.

Compared with patients who did not present for follow-up during COVID-19, patients who continued their oncologic follow-up during the pandemic were younger (p = 0.049) more likely to have received adjuvant radiation therapy (p = 0.025), and have lower household income (p = 0.031) on multivariate modeling. When patients who live in Bronx, New York, were stratified by ZIP code, there was a modest negative association (r = −0.56) between COVID-19 cases and proportion of patients who continued to follow-up during the COVID-19 period.

Conclusion

We observed a dramatic disruption in routine breast cancer follow-up during the COVID-19 pandemic. Providers and health systems should emphasize reintegrating patients who missed appointments during COVID-19 back into regular surveillance programs to avoid significant morbidity and mortality from missed breast cancer recurrences.

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A dramatic disruption in routine oncologic follow-up was observed during the COVID-19 period.

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Over half of patients with breast cancer at our center did not attend routine oncologic follow-up during COVID-19.

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Patients who were younger, had lower SES, and who received radiotherapy were more likely to follow-up during the pandemic.

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A modest negative association was observed between local ZIP code COVID-19 infection rates and follow-up attendance rate.

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.

Clinical Trials for Treatment and Prevention of HIV-Associated Malignancies in Sub-Saharan Africa: Building Capacity and Overcoming Barriers

PURPOSE

The aim of this study was to review the current status of clinical trials for HIV-associated malignancies in people living with HIV in sub-Saharan Africa (SSA) and efforts made by the AIDS Malignancy Consortium (AMC) to build capacity in SSA for HIV malignancy research.

METHODS

All malignancy-related clinical trials in 49 SSA countries on ClinicalTrials.gov were reviewed and evaluated for inclusion and exclusion criteria pertaining to HIV status. Additional studies by AMC in SSA were compiled from Web-based resources, and narrative summaries were prepared to highlight AMC capacity building and training initiatives.

RESULTS

Of 96 cancer trials identified in SSA, only 11 focused specifically on people living with HIV, including studies in Kaposi sarcoma, cervical dysplasia and cancer, non-Hodgkin lymphoma, and ocular surface squamous neoplasia. Recognizing the increasing cancer burden in the region, AMC expanded its clinical trial activities to SSA in 2010, with 4 trials completed to date and 6 others in progress or development, and has made ongoing investments in developing research infrastructure in the region.

CONCLUSION

As the HIV-associated malignancy burden in SSA evolves, research into this domain has been limited. AMC, the only global HIV malignancy-focused research consortium, not only conducts vital HIV-associated malignancies research in SSA, but also develops pathology, personnel, and community-based infrastructure to meet these challenges in SSA. Nonetheless, there is an ongoing need to build on these efforts to improve HIV-associated malignancies outcomes in SSA.

Development and Validation of a Simulation Model-Based Clinical Decision Tool: Identifying Patients Where 21-Gene Recurrence Score Testing May Change Decisions

There is a need for industry-independent decision tools that integrate clinicopathologic features, comorbidities, and genomic information for women with node-negative, invasive, hormone receptor–positive, human epidermal growth factor receptor-2–negative (early-stage) breast cancer.

Abstract 35: Racial disparity in localized breast cancer: Pooled analysis of NSABP trials

Background: The purpose of this study was to evaluate whether there are differences in distant recurrence rates between Black and White women with localized breast cancer who participated in NCI-sponsored clinical trials, and thus had access to state of the art oncologic care and lacked major comorbidities.

Methods: We analyzed pooled data from 10 NSABP trials including 10,364 patients with localized breast cancer treated with adjuvant chemotherapy (AC, n=8147) or neoadjuvant chemotherapy (NAC, n=2217), limited to those with self-reported race that was either Black (n=1006, 10.3%) or White (n=9358, 89.7%). AC/NAC included doxorubicin and cyclophosphamide, with or without a taxane. The association between race (Black vs. White) and distant relapse-free survival (DRFS) was analyzed in the overall population and stratified by AC or NAC use. Log rank tests were used to test for differences in DRFS. Multivariate Cox regression was performed to estimate risk of distant recurrence adjusted for other prognostic covariates including age (continuous), tumor size (&gt; 2 cm vs. &lt; 2 cm), ER expression (positive vs. negative), and nodal status (pathologically positive for AC cohort or clinically positive for NAC cohort vs. negative).

Results: In the AC cohort, 7,419 (91%) patients were White and 728 (9%) Black. In the NAC cohort, 1,939 (88%) were White and 278 (12%) Black. Black race was associated with an inferior DRFS in the combined AC/NAC cohort (Logrank p&lt;.0001), and in both the AC and NAC cohorts (Logrank p=0.0008 and p=0.01, respectively). After adjustment for other covariates in multivariate analysis, Black race remained significantly associated with an inferior DRFS in the combined AC/NAC cohort (HR 1.17, [95% CI 1.05-1.31], p=0.004), with similar trends noted in the AC (HR 1.17 [95% CI 1.02-1.33], p=0.03) and NAC cohort (HR 1.21 [95% CI 0.98-1.45], p=0.08). When the AC cohort was analyzed by ER status, Black race was associated with worse DRFS in ER-positive disease (HR 1.32 [95% CI 1.06-1.63], p=0.02), but not ER-negative disease (HR 1.06, [95% CI 0.87-1.30], p=0.57), although there was no statistically significant interaction with ER status (p=0.15). In the NAC cohort, Black women had a higher pathologic complete response (pCR) rate (22% vs 17%, Chi-squared test p=0.03). Black race was associated with a significantly worse DRFS in patients who did not achieve pCR (HR 1.34 [95% CI 1.06-1.63], p=0.01), but not in those who had a pCR (HR 0.89 [95% CI 0.49, 1.61], p=0.71).

Conclusion: We observed that Black women with localized breast cancer had higher distant recurrence rates than White women. This and other reports suggest that factors other than social determinants of health may be contributing to racial disparities in breast cancer outcome/progression, most notably in ER-positive disease and patients with residual disease after NAC. Future research is needed to help delineate the biological differences that contribute to these observations.

Citation Format: Gina Kim, Jessica M. Pastoriza, Jiyue Qin, Juan Lin, George S. Karagiannis, John S. Condeelis, Greg Yothers, Thomas B. Julian, Stewart J. Anderson, David Entenberg, Thomas E. Rohan, Joseph A. Sparano, Xiaonan Xue, Maja H. Oktay. Racial disparity in localized breast cancer: Pooled analysis of NSABP trials [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 35.

Association of Modifiable Risk Factors With Early Discontinuation of Adjuvant Endocrine Therapy: A Post Hoc Analysis of a Randomized Clinical Trial

IMPORTANCE

Early discontinuation of adjuvant endocrine therapy (ET) is problematic among breast cancer survivors, with previous studies suggesting that up to 50% of women do not adhere to the recommended full 5 years of ET treatment.

OBJECTIVE

To identify the association between early discontinuation of ET in the Trial Assigning Individualized Options for Treatment (TAILORx) and modifiable risk factors, polypharmacy, and types of additional medications such as antidepressants and opioids.

DESIGN, SETTING, AND PARTICIPANTS

This post hoc analysis includes a subgroup of 954 patients with breast cancer in TAILORx, a randomized clinical trial conducted from April 7, 2006, to October 6, 2010. All participants received a diagnosis of hormone receptor-positive, ERBB2-negative, axillary node-negative breast cancer and started ET within a year of study entry. Analyses were conducted in the intent-to-treat population. Statistical analysis took place from January 15, 2020, to April 6, 2021.

MAIN OUTCOMES AND MEASURES

Participants completed measures on cancer-related health-related quality of life including physical well-being and social well-being prior to initiating ET. Early discontinuation of ET was defined as discontinuation less than 4 years from initiation for reasons other than death or recurrence. Kaplan-Meier estimates were used to calculate discontinuation, and Cox proportional hazards regression joint prediction models were used to analyze the association between rates of adherence to ET with patient-level factors.

RESULTS

A total of 954 women (mean [SD] age, 56.6 [8.9] years) were included in this analysis. In a joint model, receipt of chemoendocrine therapy (vs receipt of ET only; hazard ratio [HR], 0.57; 95% CI, 0.35-0.92; P = .02) and age older than 40 years (vs ≤40 years; HR for 41-50 years, 0.39; 95% CI, 0.18-0.85; P = .02; HR for 51-60 years, 0.28; 95% CI, 0.13-0.60; P = .001; HR for 61-70 years, 0.40; 95% CI, 0.18-0.86; P = .02; and HR for >70 years, 0.23; 95% CI, 0.07-0.77; P = .02) were associated with a lower probability of early discontinuation of ET. Adjusted for these factors, a history of depression compared with no history of depression (HR, 1.82; 95% CI, 1.19-2.77; P = .005), worse physical well-being compared with better physical well-being (HR, 2.12; 95% CI, 1.30-3.45; P = .002), and worse social well-being compared with better social well-being (HR, 1.94; 95% CI, 1.20-3.13; P = .006) were individually and significantly associated with a higher probability of early discontinuation of ET. Only antidepressant use at study baseline was associated with early discontinuation (HR, 1.87; 95% CI, 1.23-2.84; P = .003).

CONCLUSIONS AND RELEVANCE

In this post hoc analysis of a randomized clinical trial, baseline patient-reported health-related quality of life components, such as poor social well-being, poor physical well-being, and comorbid depression, were significant risk factors for early discontinuation of endocrine therapies. These results support systematic screening for patient-reported outcomes and depressive symptoms to identify women at risk for discontinuation of ET.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00310180.

Perspectives on PARP inhibitors as pharmacotherapeutic strategies for breast cancer

Introduction Approximately 10% of all breast cancer cases occur in individuals who have germline pathogenic variants of the BRCA 1, BRCA 2, and other genes associated with impaired DNA damage repair that is associated with an increased risk of breast, ovarian, and other cancers. Inhibitors of poly-ADP ribose polymerase (PARP) induce synthetic lethality in cancer cells harboring such pathogenic variants.Area covered In this review, the authors review the mechanisms of action, antitumor activity, and adverse events associated with PARP inhibitors for the treatment of advanced breast cancer. The authors then summarize the area and provide their expert perspectives on the area.Expert opinion Two PARP inhibitors are approved in metastatic breast cancer, including olaparib and talozaparib. Both agents were approved based on phase III trials demonstrating that they were associated with improved progression-free survival compared with treatment of physician's choice in patients receiving second-third line therapy for locally advanced, inoperable, or metastatic breast cancer in patients with germline pathogenic BRCA 1 or BRCA2 variants.

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.

A randomized phase III post-operative trial of platinum-based chemotherapy (P) versus capecitabine (C) in patients (pts) with residual triple-negative breast cancer (TNBC) following neoadjuvant chemotherapy (NAC): ECOG-ACRIN EA1131

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Background: Pts with TNBC who have residual invasive disease (RD) after completion of NAC have a very high risk for recurrence, which is reduced by adjuvant capecitabine (C). Pre-clinical models support the use of platinum agents (P) in the TNBC basal subtype. EA1131 tested the hypothesis that invasive disease-free survival (iDFS) would not be inferior but improved in pts with basal subtype TNBC after NAC with the adjuvant use of a P instead of C (primary objective). Methods: Pts with clinical stage II/III TNBC post neoadjuvant taxane +/- anthracycline-based chemotherapy with at least 1 cm RD in the surgical specimen were randomized (1:1) to receive P (carboplatin or cisplatin once every 3 weeks for 4 cycles) or C (14/7d every 3 weeks for 6 cycles). TNBC subtype (basal vs. non-basal) was analyzed in the surgical specimen by PAM50. A non-inferiority design (non-inferiority margin of hazard ratio [HR] of 1.154) with superiority alternative (alternative HR of 0.754) was chosen, assuming a 4-year iDFS of 67% for the C arm. Non-inferiority was tested first. If non-inferiority was shown, a formal test for superiority of P compared to C would be conducted. Results: 401 participants were randomized to P or C between 2015 and 2020 (recruitment goal, 775), 310 (77%) had TNBC basal subtype disease (primary analysis population). Pts’ median age was 52 years, 71% were White and 19% Black. At diagnosis, most tumors were high grade (78%), T2 (59%), 47% N0, and 40% N1. Residual tumors were 37% ypT1, 44% ypT2, and 47% ypN0. Overall incidence of any toxicity was similar (83% with P, 80% with C), but grade 3 and 4 toxicities (no grade 5) were more common with P (25% vs 15%). After median follow-up of 18 months, 113 iDFS events (58% of full information) had occurred. 3-year iDFS for P arm was 40% (95%CI, 29%-51%) and 44% (95%CI, 32%-55%) for C arm. The HR for arms P/C was 1.09 (95% Repeated Confidence Interval, 0.62-1.90) and the probability of eventually rejecting the null of inferiority (i.e., conditional power) was 6%. The Data Safety and Monitoring Committee recommended stopping the trial at the 5th interim analysis in March 2021 since it was unlikely that the trial would be able to show non-inferiority or superiority of the P arm. Conclusions: Participants with TNBC with RD after NAC had a lower than expected 3-year iDFS regardless of study treatment. Available data show that it is very unlikely that the study would be able to establish non-inferiority of P to C. In addition, severe toxicities were more common with P. In pts with TNBC, particularly basal subtype, with at least 1 cm RD after NAC and high-risk of recurrence, adjuvant P use does not improve outcomes. Correlative analyses of RD tissue (NGS), circulating markers (ctDNA and CTC pre/post treatment), and patient-reported outcomes (PRO) questionnaires will now occur. Clinical trial information: NCT02445391.