Lew, Danika L.

Abstract Background S0221 investigated weekly vs every 2 weeks dosing of doxorubicin (A) and cyclophosphamide (C) followed by paclitaxel in patients with high-risk early breast cancer. After an interim analysis, random assignment to the 2 AC arms was stopped for futility, and the trial was modified to study only the paclitaxel schedules. Methods Between December 2003 and November 2010, a total of 2716 patients were randomly assigned in a 2 × 2 factorial design to 15 weeks of weekly A and daily C vs 6 cycles of every 2 weeks AC; and weekly paclitaxel for 12 weeks vs 6 cycles of every 2 weeks paclitaxel. Between January 2011 and January 2012, an additional 578 patients were assigned to 4 cycles of every 2 weeks AC and randomly assigned to weekly vs every 2 weeks paclitaxel. Updated survival was assessed using log-rank tests and Cox regression models. We compared outcomes by breast cancer subtype as well. Results At a median follow-up of 12.1 years, there were no statistically significant differences among the 4 treatment arms in disease-free survival (DFS) (P = .91) or overall survival (P = .34) in the original protocol. Among the 578 patients assigned AC for 4 cycles and randomly assigned to paclitaxel weekly vs every 2 weeks paclitaxel, there were no overall differences in DFS (P = .32) or overall survival (P = .42). Conclusion As there were no statistically significant outcome differences in DFS or overall survival between the studied schedules of AC and paclitaxel with extended follow-up in the original or revised protocol, either paclitaxel schedule may be recommended, with selection based on toxicity, cost, or patient preference.

Importance Breast cancer treatment is associated with cancer-related cognitive impairment (CRCI). However, the association of endocrine therapy (ET) vs chemotherapy plus endocrine therapy (CET) with CRCI is poorly understood. Objective To compare patient-reported CRCI between women with breast cancer treated with ET vs CET and to consider whether menopausal status may be associated. Design, Settings, and Participants This was a prespecified secondary analysis of RxPONDER (SWOG S1007), a multinational phase 3 randomized clinical trial of more than 5000 women with hormone receptor−positive ERBB2 -negative (formerly HER2 -negative) breast cancer with 1 to 3 involved lymph nodes and Oncotype DX (21-gene recurrence score) of 25 or less. Participants were enrolled from February 2011 to September 2017, with results first reported in December 2020. Participants were randomly assigned to CET or ET, with ongoing follow-up. This secondary analysis assessed cognitive function using the Patient-Reported Outcomes Measurement Information System Perceived Cognitive Function Concerns (PCF) questionnaire at baseline, 6, 12, and 36 months. Data were analyzed from July 2022 to August 2025. Intervention Random assignment to CET or ET. Main Outcomes and Measures Mean PCF standardized (T) scores by menopausal status over time using generalized estimating equations analysis for continuous outcomes. Results Of the 568 patients who completed the baseline questionnaire and were included in the analysis, 139 (24%) were premenopausal (median [range] age, 47.8 [28.0-56.3] years) and 429 (76%) were postmenopausal (median [range] age, 62.3 [37.3-87.6] years). Among the 274 (48%) who received CET and the 294 (52%) who received ET alone, CET was determined to have a greater negative association with patient-reported CRCI in both the pre- and postmenopausal participants during the 36-month follow-up. In the ET alone group, PCF scores for premenopausal participants decreased from baseline to 6 and 12 months (53.53, 51.51, and 51.72, respectively) but recovered to baseline (54.36) at 36 months. For postmenopausal participants, mean PCF scores were essentially stable (51.72, 51.13, 51.11, and 51.70, respectively); however, in the CET group, PCF scores for both pre- and postmenopausal participants decreased from baseline to 6 and 12 months (premenopausal, 52.84, 49.27, 48.04; postmenopausal, 50.65, 48.39, 47.13, respectively) and did not return to baseline at 36 months (premenopausal, 49.25; postmenopausal, 48.44). The difference in longitudinal mean PCF scores over time between CET and ET groups was −3.02 (95% CI, −5.33 to −0.72; P = .01) for premenopausal and −2.37 (95% CI, −3.92 to −0.82; P = .003) for postmenopausal participants. Conclusions and Relevance This secondary analysis of the RxPONDER found that CET had a greater negative association with patient-reported CRCI compared to ET alone in both pre- and postmenopausal participants over a 36-month follow-up period. Interventions to prevent or treat CRCI are needed to improve the long-term quality of life of these patients treated with chemotherapy. Trial Registration ClinicalTrials.gov Identifier: NCT01272037

Abstract Background The phase III RxPONDER trial has affected treatment for node-positive (1-3), hormone receptor-positive, HER2-negative breast cancer with a 21-gene recurrence score (RS) less than 26. We investigated how these findings apply to different racial and ethnic groups within the trial. Methods The trial randomly assigned women to endocrine therapy (ET) or to chemotherapy plus ET. The primary clinical outcome was invasive disease-free survival (IDFS), with distant relapse-free survival (DRFS) as a secondary outcome. Multivariable Cox models were used to evaluate the association between race/ethnicity and survival outcomes, adjusting for clinicopathological characteristics, RS, and treatment. Results A total of 4048 women with self-reported race/ethnicity were included: Hispanic (15.1%), non-Hispanic Black (NHB) (6.1%), Native American/Pacific Islander (0.8%), Asian (8.0%), and non-Hispanic White (NHW) (70%). No differences in RS distribution, tumor size, or number of positive nodes were observed by race/ethnicity. Relative to NHWs, IDFS was worse for NHB participants (5-year IDFS 91.6% vs 87.1%, HR = 1.37; 95% CI = 1.03 to 1.81) and better for Asians (91.6% vs 93.9%, HR = 0.64; 95% CI = 0.46 to 0.91). Relative to NHW, DRFS was worse for NHB participants (5-year DRFS 95.8% vs 91.0%, HR = 1.65; 95% CI = 1.17 to 2.32) and better for Asians (95.8% vs 96.7%, HR = 0.59; 95% CI = 0.37 to 0.95). Adjusting for clinical characteristics, particularly body mass index, diminished the effect of race on outcomes. Chemotherapy treatment efficacy did not differ by race/ethnicity. Conclusions NHB women had worse clinical outcomes compared with NHWs in the RxPONDER trial despite similar RS and comparable treatment. Our study emphasizes the persistent racial disparities in breast cancer outcomes while highlighting complex interactions among contributing factors. Trial Registration ClinicalTrials.gov: NCT01272037.

PURPOSE Phosphatidylinositol 3-kinase/AKT-serine threonine kinase/mammalian target of rapamycin (mTOR) pathway abnormalities contribute to endocrine resistance. Everolimus, an mTOR inhibitor, improved progression-free survival in hormone receptor–positive metastatic breast cancer (BC) when combined with endocrine therapy (ET). In this phase III randomized, placebo-controlled trial, we assessed the efficacy of everolimus + ET as adjuvant therapy in high-risk, hormone receptor–positive, human epidermal growth factor receptor 2–negative BC after adjuvant/neoadjuvant chemotherapy. METHODS Patients were randomly assigned 1:1 to physician's choice ET and 1 year of everolimus (10 mg orally once daily) or placebo stratified by risk group. The primary end point was invasive disease-free survival (IDFS) evaluated by a stratified log-rank test with the hazard ratio (HR) estimated by Cox regression. Subset analyses included preplanned evaluation by risk group and exploratory analyses by menopausal status and age. Secondary end points included overall survival (OS) and safety. Everolimus did not improve IDFS/OS when added to ET in patients with early-stage high-risk, hormone receptor–positive BC. RESULTS One thousand and nine hundred thirty-nine patients were randomly assigned with 1,792 eligible for analysis. Overall, no benefit of everolimus was seen for IDFS (HR, 0.94 [95% CI, 0.77 to 1.14]) or OS (HR, 0.97 [95% CI, 0.75 to 1.26]). The assumption of proportional hazards was not met suggesting significant variability in the HR over time since the start of treatment. In an unplanned subgroup analysis among postmenopausal patients (N = 1,221), no difference in IDFS (HR, 1.08 [95% CI, 0.86 to 1.36]) or OS (HR, 1.19 [95% CI, 0.89 to 1.60]) was seen. In premenopausal patients (N = 571), everolimus improved both IDFS (HR, 0.64 [95% CI, 0.44 to 0.94]) and OS (HR, 0.49 [95% CI, 0.28 to 0.86]). Treatment completion rates were lower in the everolimus arm compared with placebo (48% v 73%) with higher grade 3 and 4 adverse events (35% v 7%). CONCLUSION One year of adjuvant everolimus + ET did not improve overall outcomes. Subset analysis suggests mTOR inhibition as a possible target for patients who remain premenopausal after chemotherapy.

Abstract BACKGROUND: Abnormalities of the PI3kinase/AKT/mTOR signaling network are common in breast cancer (BC) and are associated with endocrine resistance. Everolimus, an mTOR-inhibitor increased PFS when combined with endocrine therapy (ET) in the metastatic setting and is thought to revert endocrine resistance. S1207 is a phase III randomized, placebo-controlled trial evaluating the role of everolimus in combination with ET in the adjuvant setting among patients with high-risk hormone receptor-positive, HER2-negative BC (NCT01674140). METHODS: Eligible patients were >18 years of age with histologically confirmed invasive hormone receptor-positive and HER2-negative high-risk BC. Four risk groups were defined as: 1) > 2cm node-negative disease (or pN1mi), and either an Oncotype DX® Recurrence Score (RS) > 25 or MammaPrint® high-risk category (MP high); 2) 1-3 positive nodes and either RS >25, MP high or a pathological grade 3 tumor; 3) >4 positive lymph nodes. Patients treated with neoadjuvant chemotherapy were eligible if: 4) after surgery had >1 lymph node involvement. Patients were randomized 1:1 to physician’s choice adjuvant ET in combination with one year of everolimus (10 mg PO daily) or ET plus placebo stratified by risk group. The primary endpoint was invasive disease-free survival (IDFS) evaluated by a stratified log-rank test. Secondary endpoints included overall survival (OS) and safety. The hazard ratio (HR) for treatment efficacy was estimated using Cox regression with stratification by risk groups. Subset analyses included preplanned evaluation within risk group and exploratory analyses of menopausal status and age. RESULTS: 1,939 patients were randomized between September 2013 and May 2019, of them 1,792 were eligible and included in the analysis (896 per arm). Primary reason for ineligibility was timing after chemotherapy/radiation or not high risk. Median age was 54 years (22-85) and 32% were premenopausal. With a median follow-up of 50.5 months, there were 389 IDFS events as of May 2022 (data cutoff). 5-year IDFS was 74.8% among patients treated with everolimus and 73.9% among patients treated with placebo, HR=0.93 (95% CI 0.76-1.14). However, the proportional hazards assumption was violated (p=0.02) suggesting differential treatment effect over time. The HR during the one year of treatment was 0.72 (95% CI 0.47-1.10) while after one year it was 1.00 (95% CI 0.80-1.26). The 5-year OS was 87.6% in the everolimus arm and 85.5% in the placebo arm, HR=0.98 (95% CI 0.75-1.28). Analysis by risk group did not show higher everolimus benefit as risk increased. No difference in IDFS or OS was seen among postmenopausal patients (IDFS HR=1.08 [95% CI 0.85-1.36], OS HR=1.19 [95% CI 0.87-1.61]). Among premenopausal patients, everolimus was associated with improved IDFS (HR=0.63 [95% CI 0.43-0.93]) and OS (HR=0.48 [95% CI 0.26-0.88]). Treatment completion of randomized therapy was lower in the everolimus arm compared to placebo (47.9% v 72.7%). Grade 3 and 4 toxicities were noted in 6.5% and 0.5% of patients in the placebo arm and in 31.2% and 3.7% in the everolimus arm respectively. CONCLUSIONS: Addition of one year of adjuvant everolimus to standard adjuvant ET did not improve IDFS or OS and was associated with low completion rate and increased AEs. Among premenopausal patients there was a benefit in IDFS and OS that is hypothesis generating. Future translational studies will evaluate potential predictors of everolimus benefit and drug toxicity. Citation Format: Marianna Chavez, Jieling Miao, Lajos Pusztai, Matthew P. Goetz, Priya Rastogi, Patricia A. Ganz, Eleftherios (Terry) Mamounas, Soonmyung Paik, Hanna Bandos, Wajeeha Razaq, Anne O’Dea, Virginia Kaklamani, Andrea L.M. Silber, Lisa E. Flaum, Eleni Andreopolu, Joseph Baar, Albert G. Wendt, Jennifer F. Carney, Priyanka Sharma, Julie R. Gralow, Danika L. Lew, William E. Barlow, Gabriel N. Hortobagyi. Results from a phase III randomized, placebo-controlled clinical trial evaluating adjuvant endocrine therapy +/- 1 year of everolimus in patients with high-risk hormone receptor-positive, HER2-negative breast cancer: SWOG S1207 [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 GS1-07.

Abstract Background: We previouslyreported that invasive disease-free survival (IDFS), the primary outcome, and distantdisease-free survival (DDFS), a secondary outcome, differed by menopausalstatus in a pre-specified analysis. Here,we report updates on IDFS and DDFS with additional follow-up, as well as distantrecurrence-free interval (DRFI) and post hoc analyses in premenopausal women.Methods: Eligibilitycriteria included women > 18 years of age with HR+, HER2-BC and 1-3 +LN and no contraindications to taxane and/or anthracycline basedCT. DRFI was defined as time to distant recurrence or death from breast cancer.Analyses were intent-to-treat among eligible pts. We performed a post hocanalysis evaluating IDFS between treatment arms in premenopausal pts with pN1mi.In addition, we conducted a two-year landmarked IDFS analysis by ovarianfunction suppression (OFS) or not in the ET arm, as well as by regularmenstrual periods or not in both treatment arms.Results: Among the 4,984eligible pts, there were 553 IDFS events and median follow-up of 6.1 years.Postmenopausal women do not have any IDFS or DDFS benefit with CT; however, 5-yearabsolute benefits for IDFS and DDFS with CT for premenopausal pts were 5.9% and3.3%, respectively. In pre-menopausal pts, CT was associated with improved DRFIfor all RS values < 25, with an absolute improvement of 2.3% for RS0-13 and of 2.8% for RS 14-25. Among premenopausal pts, 12.4% (n=206) had pNmi)disease. In a post hoc analysis, there was a trend for CT benefit for thosewith pNmi [hazard ratio (HR)=0.44, confidence interval (CI)=0.18-1.08]. Therewere only 22 IDFS events. Only 17.2% of premenopausal pts assigned to ETunderwent OFS in the first 24 months and in two-year landmarked analysis, therewas no IDFS difference in those who underwent OFS or not (HR=0.88,CI=0.47-1.63). In premenopausal women assigned to ET, 58.9% stopped havingperiods within the first 24 months, and have anumerically improved IDFS compared to those who continued regular periods (HR=1.48,CI: 0.92-2.40). Among premenopausal assigned to CT followed by ET, 80.8%stopped having periods within the first 24 months and have a numericallyimproved IDFS compared to those who continue to have regular periods (HR=1.56, CI:0.85-2.86).Discussion: In accordancewith the differential IDFS and DDFS benefit based upon menopausal status inS1007, premenopausal pts with 1-3+LN and RS < 25 had a statisticallysignificant improvement in DRFI with the addition of CT. A small proportion of S1007premenopausal participants underwent OFS. The role of OFS as it relates to CTbenefit cannot be determined from this study. A future randomized trial should address the clinical question if OFScan replace CT in premenopausal pts with HR+/HER2-, node-positive breast cancer.Funding: Supported by National Cancer Institute grants U10CA180888, U10CA180819,U10CA180820, U10CA180821, U10CA180868, U10CA180863, and in part by Susan G.Komen for the Cure® Research Program, The Hope Foundation for Cancer Research,Breast Cancer Research Foundation, and Genomic Health, Inc. Citation Format: Kevin M Kalinsky, William E Barlow, Julie R Gralow, Funda Meric-Bernstam, Kathy S Albain, Daniel F Hayes, Nancy U Lin, Edith A Perez, Lori A Goldstein, Stephen KL Chia, Sukhbinder Dhesy-Thind, Priya Rastogi, Emilio Alba, Suzette Delaloge, Miguel Martin, Catherine M Kelly, Manuel Ruiz-Borrego, Miguel Gil-Gil, Claudia H Arce-Salinas, Etienne GC Brain, Eun Sook Lee, Jean-Yves Pierga, Begoña Bermejo, Manuel Ramos-Vasquez, Kyung Hae Jung, Jean-Marc Ferrero, Anne Schott, Steven Shak, Priyanka Sharma, Danika Lew, Jieling Miao, Debasish Tripathy, Lajos Pusztai, Gabriel Hortobagyi. Updated results from a phase 3 randomized clinical trial in participants (pts) with 1-3 positive lymph nodes (LN), hormone receptor-positive (HR+) and HER2-negative (HER2-) breast cancer (BC) with recurrence score (RS) ≤ 25 randomized to endocrine therapy (ET) +/- chemotherapy (CT): SWOG S1007 (RxPONDER) [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 GS2-07.

Abstract Funding: Supported by National Cancer Institute grants U10CA180888, U10CA180819, U10CA180820, U10CA180821, U10CA180868, U10CA180863; and in part by Susan G. Komen for the Cure® Research Program, The Hope Foundation for Cancer Research, Breast Cancer Research Foundation, and Genomic Health, Inc. Acknowledgement: The authors wish to thank Dr. Ana M. Gonzalez-Angulo, MD, for her invaluable contributions to the design and implementation of this study. Background: The clinical utility of the RS to determine CT benefit is well established in pts with HR+, HER2-, axillary lymph node (LN)-negative BC. Retrospective analyses from SWOG S8814 support the potential prognostic and predictive role of RS for CT benefit in postmenopausal pts with LN+ BC. SWOG S1007 is a prospective, randomized trial of endocrine therapy (ET) vs. chemoendocrine therapy (CET) in women with 1-3 +LN and a RS < 25 (NCT01272037). Methods: Eligibility criteria included women > 18 years of age with HR+, HER2- BC and 1-3 +LN and no contraindications to taxane and/or anthracycline based CT. Women with a RS < 25 were randomized to receive ET or CET in 1:1 randomization using 3 stratification factors: (1) RS (0-13 vs.14-25); (2) menopausal status; and (3) axillary nodal dissection vs. sentinel node biopsy. The primary objective was to determine the effect of CT on invasive disease-free survival (IDFS) and whether the effect depended on the RS. The primary analysis was to test for a significant interaction of the treatment arm and continuous RS using a Cox regression model for IDFS, adjusting for treatment, RS, and menopausal status. A total of 832 IDFS events were expected for the final analysis. Secondary objectives included overall survival (OS). The protocol specified that interaction between treatment and the stratification variables was to be tested and, if significant, separate analyses performed by stratum. Annual interim analyses were planned starting at 24% of events. At the third interim analysis with 410 IDFS events, the Data and Safety Monitoring Committee recommended reporting results, with a decision by the NCI’s Cancer Therapy Evaluation Program, the study sponsor. Results: Of the 9,383 women screened from 2/28/11-9/29/17, 5,083 pts (54.2%) were randomized. With a median follow-up of 5.1 years, 447 IDFS events have been observed. For the primary analysis, the interaction test for CT benefit and continuous RS was not statistically significant, p=0.30. In a model with CT, RS, and menopausal status (no interaction term), higher continuous RS was associated with worse IDFS [HR 1.06, 2-sided p<0.001, 95% Confidence Interval (CI) 1.04-1.07], and CT was associated with an improvement in IDFS (HR 0.81, p=0.026, 95% CI 0.67-0.98). In a pre-specified analysis, a significant interaction was identified between CT and menopausal status (p=0.004), necessitating separate analyses by menopausal status. In postmenopausal pts (N=3350, 67%), adjusting for continuous RS, the HR for CET vs. ET was not significant (HR=0.97, p=0.82, 95% CI 0.78-1.22; 5-year IDFS 91.6% vs. 91.9%) indicating no benefit from CT. In premenopausal pts (N=1665, 33%), the HR (0.54) was statistically significant (p=0.0004, 95% CI 0.38-0.76; 5-year IDFS 94.2% vs. 89.0%), indicating CT benefit. In premenopausal pts, ovarian suppression was performed in 15.9% vs. 3.7% (ET vs. CET), and 47.9% vs. 26.4% reported menstruation after 6 months of treatment. Although the number of events is limited, the HR for treatment adjusted by RS for OS in premenopausal pts was 0.47 (p=0.032, 95% CI 0.24-0.94). At this time, there is no differential effect with CT in regard to other stratification factors. Conclusions: There is a significant differential treatment effect of CT benefit based on RS for premenopausal vs. postmenopausal women requiring separate analyses. While only 54% of the protocol specified events are recorded and pts will be followed for 15 years, the current data show that adjuvant therapy can be de-escalated to ET alone in postmenopausal pts with a RS < 25 and 1-3 +LN. However, there is a strong IDFS benefit for CET in premenopausal pts, with an early indication of an OS improvement. Citation Format: Kevin Kalinsky, William E Barlow, Funda Meric-Bernstam, Julie R Gralow, Kathy S Albain, Daniel Hayes, Nancy Lin, Edith A Perez, Lori J Goldstein, Stephen Chia, Subkhbinder Dhesy-Thind, Priya Rastogi, Emilio Alba, Suzette Delaloge, Miguel Martín, Miguel Gil Gil, Claudia Arce-Salinas, Etienne Brain, In Hae Park, Jean-Yves Pierga, Ana Hernandez Lluch, Manuel Ramos Vasquez, Manuel Ruiz Borrego, Kyung Hae Jung, Jean-Marc Ferrero, Anne Schott, Steve Shak, Priyanka Sharma, Danika L Lew, Jieling Miao, Debu Tripathy, Gabriel Hortobagyi, Lajos Pusztai. First results from a phase III randomized clinical trial of standard adjuvant endocrine therapy (ET) +/- chemotherapy (CT) in patients (pts) with 1-3 positive nodes, hormone receptor-positive (HR+) and HER2-negative (HER2-) breast cancer (BC) with recurrence score (RS) < 25: SWOG S1007 (RxPonder) [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr GS3-00.

CRA1008 The full, final text of this abstract will be available at abstract.asco.org at 7:30 AM (EDT) on Monday, June, 3, 2013, and in the Annual Meeting Proceedings online supplement to the June 20, 2013, issue of Journal of Clinical Oncology. Onsite at the Meeting, this abstract will be printed in the Monday edition of ASCO Daily News.

11051 Background: A serious complication associated with breast cancer treatment is the increased risk for development of therapy-related acute myeloid leukemia (t-AML). To evaluate and possibly identify patients (pts) at high risk for development of t-AML, the Southwest Oncology Group asked whether dose-intensive adjuvant regimens for high risk breast cancer pts induced genetic damage to hematopoietic stem cells (HSC), defined by the emergence of clonal hematopoiesis, an early marker of HSC damage. Methods: 274 pts consented to the clonal hematopoiesis study objective of S0012, a randomized clinical trial of standard doxorubicin and cyclophosphamide followed by weekly paclitaxel (arm 1, 129 pts) vs. weekly doxorubicin and daily oral cyclophosphamide plus G-CSF followed by weekly paclitaxel (arm 2, 145 pts) as neoadjuvant therapy for inflammatory and locally advanced breast cancer. Two different clonality assays were used: the HUMARA (HUMan Androgen Receptor) Assay to estimate the incidence of early genetic damage by clonal proliferation and microsatellite instability (MSI) testing at 5 loci (Bat 26, Bat 40, APC, Mfd, D2S123), common ‘hotspots‘ in t-AML, to screen for loss of heterozygosity or defective DNA mismatch repair mechanisms. Blood samples were evaluated prior to treatment and at 6 and 12 mos post-surgery for emergence of clonal hematopoiesis. Results: Of the 274 pts enrolled, follow-up clonal hematopoiesis samples were available for 195 pts; 96 pts on arm 1 and 99 pts on arm 2. Both HUMARA and MSI results were negative for clonal hematopoiesis in 96% of samples analyzed. In 14 cases, the HUMARA assay suggested that a clonal population was present, but MSI analysis was negative. No cases were HUMARA+/MSI+. With a median follow-up of 19.6 mos, only one pt has developed t-AML 3 yr 5 mos post randomization. Her clonal hematopoiesis test samples at 6 and 12 mos following treatment were negative. Conclusions: Clonal hematopoiesis assays performed within the first year following neoadjuvant therapy and surgery on S0012 failed to identify an emerging clonal HSC population. Longer clinical follow-up will be necessary to define the positive predictive value of detecting clonal hematopoiesis in the 14 HUMARA+/MSI- cases as a harbinger of t-AML. No significant financial relationships to disclose.

Abstract Background Adjuvant bisphosphonates, when given in a low-estrogen environment, can decrease breast cancer recurrence and death. Treatment guidelines include recommendations for adjuvant bisphosphonates in postmenopausal patients. SWOG/Alliance/Canadian Cancer Trials Group/ECOG-ACRIN/NRG Oncology study S0307 compared the efficacy of three bisphosphonates in early-stage breast cancer. Methods Patients with stage I–III breast cancer were randomly assigned to 3 years of intravenous zoledronic acid, oral clodronate, or oral ibandronate. The primary endpoint was disease-free survival (DFS) with overall survival as a secondary outcome. All statistical tests were two-sided. Results A total of 6097 patients enrolled. Median age was 52.7 years. Prior to being randomly assigned, 73.2% patients indicated preference for oral vs intravenous formulation. DFS did not differ across arms in a log-rank test (P = .49); 5-year DFS was 88.3% (zoledronic acid: 95% confidence interval [CI] = 86.9% to 89.6%), 87.6% (clodronate: 95% CI = 86.1% to 88.9%), and 87.4% (ibandronate: 95% CI = 85.6% to 88.9%). Additionally, 5-year overall survival did not differ between arms (log rank P = .50) and was 92.6% (zoledronic acid: 95% CI = 91.4% to 93.6%), 92.4% (clodronate: 95% CI = 91.2% to 93.5%), and 92.9% (ibandronate: 95% CI = 91.5% to 94.1%). Bone as first site of recurrence did not differ between arms (P = .93). Analyses based on age and tumor subtypes showed no treatment differences. Grade 3/4 toxicity was 8.8% (zoledronic acid), 8.3% (clodronate), and 10.5% (ibandronate). Osteonecrosis of the jaw was highest for zoledronic acid (1.26%) compared with clodronate (0.36%) and ibandronate (0.77%). Conclusions We found no evidence of differences in efficacy by type of bisphosphonate, either in overall analysis or subgroups. Despite an increased rate of osteonecrosis of the jaw with zoledronic acid, overall toxicity grade differed little across arms. Given that patients expressed preference for oral formulation, efforts to make oral agents available in the United States should be considered.