Although cancer prevention, care, and survivorship in the United States have dramatically improved over the last decade, inequities in morbidity and mortality among under-resourced populations have grown, mostly attributed to structural, societal, and institutional factors. To address inequities in cancer-related outcomes, community-engaged research (CEnR) and practice remains essential. Community-engaged research is generally supported by Community Outreach and Engagement (COE) units in National Cancer Institute-designated cancer centers. For more than a decade, COE remains a requirement for comprehensive designation and is a significant factor in the overall cancer center scoring. Community engagement occurs on a continuum from community-engaged to community-based participatory research. Engaging communities experiencing inequities in cancer incidence, morbidity, and mortality to ameliorate factors contributing to poorer cancer-related outcomes remains a goal, albeit a challenging one. This commentary details both novel and successful approaches that researchers throughout the country have used to engage communities to address cancer-related inequities in their catchment areas by leveraging COE infrastructure to facilitate CEnR across research programs. We also highlight and forward recommendations from a recent scientific pre-conference workshop. Cancer center-led CEnR is critical to engaging with key communities, and yet there are tremendous opportunities to better articulate and implement approaches to effective engagement. Internal inequities and barriers in COE infrastructures and how researchers, directors, and stakeholders can collaborate to optimize cancer health outcome/CEnR are discussed, in addition to potential solutions involving collaboration with upstream policy stakeholders. In this commentary, we emphasize why this work remains an ongoing but critical priority.

BACKGROUND:Whether outcomes of germline BRCA1/2 (gBRCA1/2)-associated breast cancer differ compared with sporadic tumors is controversial. We explored the impact of gBRCA1/2 pathogenic variant (PV) status beyond established prognostic features. METHODS:We conducted 2 retrospective, matched cohort studies comparing gBRCA1/2 PV carriers and noncarriers with HER2-negative, stage I-III breast cancer (Clinical Outcomes Quality Database [COQD] cohort: 185 carriers, 555 noncarriers; Young Women's Breast Cancer Study [YWS] cohort: 113 carriers, 226 noncarriers). Matching factors were age, stage, hormone receptor status, and year of diagnosis. Clinicopathological features, treatments, and survival outcomes were compared between carriers and noncarriers. RESULTS:Most patients in COQD had stage I-II disease (87.2%), and more carriers than noncarriers had genetic testing before diagnosis (33% vs 5.6%, P < .001). In YWS, 22.7% of patients had stage III tumors, and few were tested before diagnosis (14.8% of carriers vs 1.7% of noncarriers; P < .001). Carriers in COQD received chemotherapy more often than noncarriers (81.1 vs 67.0%, P < .001), including platinum (P = .010); the proportion was similar for carriers and noncarriers in YWS. After adjusting for chemotherapy, relapse-free survival was longer in carriers than noncarriers in COQD (adjusted hazard ratio = 0.48 [95% CI = 0.26 to 0.87], P = .016), and a favorable trend was observed for other survival outcomes in both cohorts. Triple-negative tumors appeared to drive the differences. CONCLUSIONS:We observed a trend toward improved outcomes in gBRCA1/2 PV carriers compared with noncarriers. These findings suggest that carriers should not receive more aggressive treatment solely based on their germline mutation status. Prospective clinical trials in this population are warranted.

PURPOSE:To evaluate the clinical benefit of extended endocrine therapy (eET) after 5 years of adjuvant treatment with luteinizing hormone-releasing hormone agonists (LHRHa) in premenopausal women with node-positive, hormone receptor-positive early breast cancer (eBC). METHODS:We conducted a cohort study analysis on two prospectively collected data sets (the Young Women's Breast Cancer Study and IEO Breast Cancer Cohort). Eligible patients were diagnosed with eBC at age ≤40 years (between 2005 and 2016), had node-positive, hormone receptor-positive disease, and remained premenopausal after 5 years of adjuvant LHRHa with no evidence of recurrence. The primary end point was invasive breast cancer-free survival (IBCFS), calculated from the sixth year after the initiation of adjuvant endocrine therapy (ET; study baseline), and adjusted through the propensity score (PS) weighting analysis. RESULTS:A total of 501 patients were included in the analysis: 287 received eET for a median duration of 3.7 years (IQR, 2.3-5.0), including 48% tamoxifen monotherapy and 52% LHRHa plus tamoxifen or aromatase inhibitor. After a median follow-up of 7.3 years from the study baseline, the PS weighted IBCFS rates at 5 years were 85% in the eET group and 78% in the non-eET group (hazard ratio [HR], 0.63 [95% CI, 0.44 to 0.89]; P = .0135). The PS weighted distant recurrence-free survival rates at 5 years were 91% and 83% in the eET and non-eET group, respectively (cause-specific HR, 0.49 [95% CI, 0.31 to 0.79]). In both groups, bone fractures and major cardiovascular events were reported in 1% of patients. CONCLUSION:In this cohort study analysis, extending ET in premenopausal patients with node-positive eBC after 5 years of LHRHa treatment was associated with a clinically meaningful reduction in both invasive and distant breast cancer recurrences.

Importance:Premenopausal patients with node-positive, hormone receptor-positive, early breast cancer derive benefit from extended endocrine therapy (EET) following 5 years of luteinizing hormone-releasing hormone (LHRH) agonist-based treatment. The benefit of EET may differ according to surrogate breast cancer subtypes in postmenopausal patients. Objective:To evaluate the risk of invasive and distant recurrence across all surrogate breast cancer subtypes among patients with node-positive, hormone receptor-positive early breast cancer who remained premenopausal after completing 5 years of adjuvant therapy with an LHRH agonist who received and did not receive EET. Design, Setting, and Participants:This multicenter cohort study conducted in the United States and Italy used data from 2 prospectively maintained datasets: the Young Women's Breast Cancer Study and the European Institute of Oncology Breast Cancer cohort. Eligible patients were diagnosed with early breast cancer at 40 years of age or younger between January 2005 and December 2016, had node-positive hormone receptor-positive disease, and remained premenopausal after 5 years of adjuvant LHRH agonist therapy with no evidence of recurrence. Median (IQR) follow-up was 7.3 (4.9-10.3) years. Data were analyzed June 2025. Exposure:EET (with tamoxifen monotherapy, LHRH agonist plus tamoxifen, or LHRH agonist plus aromatase inhibitor), irrespective of the duration of EET, measured at study baseline (defined as the first day of the sixth year after the initiation of adjuvant ET). Main Outcomes and Measures:Invasive breast cancer-free survival and distant recurrence-free survival (DRFS) distributions were estimated using the adjusted Kaplan-Meier method among patients with or without the exposure, weighted through propensity score (PS) weighting analysis, with the scientific approach. Results:In total, 487 patients were included (median [IQR] age at diagnosis, 37 [35-39] years in the EET group and 37 [33-39] years in the no EET group), and 276 received EET for a median (IQR) duration of 3.7 (2.2-5.0) years. Overall, 89 patients (18%) had luminal A-like disease, 298 (61%) had luminal B-like disease, and 100 (21%) had ERBB2 (formerly HER2)-positive disease. The PS-weighted hazard ratio (HR) for invasive breast cancer-free survival comparing the EET with the no EET group was 0.68 (95% CI, 0.32-1.45) in luminal A-like, 0.63 (95% CI, 0.40-1.00) in luminal B-like/ERBB2-negative, and 0.62 (95% CI, 0.21-1.87) in ERBB2-positive subgroups. The cause-specific PS-weighted HR for DRFS was 0.25 (95% CI, 0.08-0.75) in luminal A-like, 0.54 (95% CI, 0.32-0.94) in luminal B-like/ERBB2-negative, and 0.54 (95% CI, 0.12-2.53) in ERBB2-positive subgroups. Conclusions and Relevance:In this cohort study, a lower estimated risk with EET use was observed across all surrogate breast cancer subtypes. However, the lower estimated risk was greatest among patients with luminal A-like disease, a finding that warrants confirmation in larger, prospective cohorts.

BACKGROUND:Breast cancer (bc) diagnosed during pregnancy or postpartum often presents with aggressive features, potentially influenced by hormonal, immunologic, and tissue remodeling changes. Studies have suggested that postpartum bc may be associated with worse outcomes, though most evidence is retrospective and constrained by methodological limitations. This study evaluated associations between pregnancy history, recency of childbirth, and long-term outcomes in a prospective cohort of young patients with early-stage bc. PATIENTS AND METHODS:Patients aged ≤40 years with stage I-III bc enrolled in the Young Women's Breast Cancer Study were categorized at diagnosis as nulligravid, nulliparous, pregnant, or parous (≤5 vs 5 to 10 years postpartum). Analyses were stratified by bc subtype [estrogen receptor-positive [ER+]/HER2-, HER2+, and triple-negative (TNBC)], with distant recurrence-free survival (DRFS) as the primary endpoint. RESULTS:Among 859 patients, 257 (29.9%) were nulligravid, 50 (5.8%) nulliparous, 37 (4.3%) pregnant, and 515 (60.0%) parous. Pregnant patients had proportionally more TNBC, nodal involvement, T3/T4, and grade 3 tumors. After 11.1 years median follow-up, pregnancy or postpartum status was not independently associated with DRFS in multivariable models adjusted for age, tumor characteristics, and treatment, with consistent findings across ER+/HER2-, HER2+, and TNBC subtypes. Sensitivity analyses, including further categorization of postpartum diagnoses (<2 vs 2 to 5 years), yielded consistent results. CONCLUSIONS:Pregnancy history and recency of childbirth were not independently associated with long-term DRFS. Despite more aggressive features at diagnosis, patients diagnosed during or after pregnancy had comparable outcomes after adjustment, suggesting no adverse prognostic impact. CLINICAL TRIAL REGISTRATION:NCT01468246 (https://clinicaltrials.gov/study/NCT01468246?term=NCT01468246&rank=1).

To assess whether a virtual, cancer survivorship-focused continuing medical education (CME) course affected awareness of cancer survivorship care and examined barriers to implementing practice changes. We surveyed medical professionals caring for patients and survivors of cancer before, during, and after online course participation from 2021 to 2024. Pre- and post-course test scores across four modules addressing care for patients with various cancer types, cancer and treatment effects, and survivors’ psychosocial and general health were analyzed using paired samples t-tests to determine participant knowledge. Post-course evaluations were analyzed using descriptive statistics and Fisher’s exact tests to measure perceived barriers in implementing practice changes. Three hundred fifty-seven medical professionals registered for the CME course; 193 (54.1

Background: Adolescents and young adults (AYAs) living with metastatic breast cancer (MBC) experience physical and psychosocial difficulties often amplified by a disrupted life trajectory. Data regarding age-specific needs and concerns of AYAs within the context of the MBC disease experience are lacking. We describe psychosocial and supportive care concerns among AYAs with MBC to better understand and address their survivorship needs over time. Methods: AYAs (18-39 years) diagnosed with MBC participating in an ongoing prospective intervention study (Young, Empowered and Strong [YES], NCT04379414) at Dana-Farber Cancer Institute complete an electronic REDCap survey at baseline (BL) and every 6 months (mos) post-enrollment for 3 years, then annually for 2 years. Through the YES web-based portal, participants respond to electronic patient-reported outcomes and receive information on ways to manage symptoms and concerns they endorse in addition to other resources. Here we describe REDCap survey-reported psychosocial and supportive care concerns at BL, 6-, and 12-mos. Clinical information was abstracted from medical records. Concerns were assessed with items adapted from the AYA Health Outcomes and Patient Experience survey and dichotomized (not at all/a little, somewhat/very concerned). Financial burden was assessed using National Health Interview Survey items such as burden from diagnosis (a little/none, a lot/some). We used generalized estimating equations to model proportional changes in concerns from BL to 6- and 12-mos. Results: As of 5/1/2024, 100 of 103 (97.1%) women sent the BL survey completed it. Of those eligible (N=91), 53 (58.2%) completed the 6 mo survey; 23 (25.3%) did not respond, 11 (12.1%) died, and 4 (4.3%) had withdrawn. At 12-mo, 40 of the 75 eligible participants responded (53.3%); 24 (32%) did not respond, 9 (12%) died, and 2 (2.7%) had withdrawn. Median age at enrollment was 37 years (range=26-45), 33 years at MBC diagnosis (range=22-39), and time from metastatic diagnosis to enrollment was 15 mos (range=0.2-96.3). Time from primary to metastatic diagnosis varied: 34.0% de novo, 17.0%, 3 mos-2 years and 49.0% ≥2 years. Most participants were white (85%), non-Hispanic (92%), and had a college degree or higher (80%). Concerns were pervasive at BL, but many concerns lessened over time including the possibility of the cancer worsening (BL: 92.0% v. 6 mo: 86.8% v. 12 mo: 71.8%, p=0.02), potential long-term side effects of treatment (71% v. 56.6% v. 47.4%, p= 0.01), potential long-term effects of cancer on health (70.0% v. 60.4% v. 46.2%, p=0.03), and a family member’s risk of getting cancer (39% v. 41.5% v. 20.5%, p=0.01). Though other concerns followed a similar pattern over time, differences were not statistically significant: how to check for signs of cancer worsening (61.6% v. 52.8% v. 41.0%, p=0.06), physical fitness/exercise (54.6% v. 50.9% v. 43.6%, p=0.48), nutrition/healthy diet (51.5% v. 45.3% v. 35.9%, p=0.19), and having financial support for medical care (40.0% v. 45.3% v. 33.3%, p=0.31). BL financial burden difficulties were endorsed least (a lot/some: 41.2%) followed by those at 12- (47.4%) and 6-mo (55.8%) but were not significantly different (p=0.14). Conclusion: Among AYAs with MBC enrolled in the YES study, selected cancer-related concerns improved over time, still a substantial proportion continue to experience concerns over time. These preliminary results suggest an intervention to support young survivors with MBC may improve AYA concerns while others may need additional attention; alternatively, some concerns may wane as patients adapt to diagnosis and treatment. Addressing concerns such as financial toxicity, physical and mental health, disease progression, and treatment side effects, may optimize disease expectations and wellbeing. Citation Format: Kate E Dibble, Yue Zheng, Shoshana M Rosenberg, Tal Sella, Philip Poorvu, Craig Snow, Sarah Sammons, Nancy U Lin, Jennifer W Mack, Ann H Partridge. Supportive care concerns of young women living with metastatic breast cancer from an ongoing prospective virtual intervention [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2024; 2024 Dec 10-13; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2025;31(12 Suppl):Abstract nr P2-01-06.

BACKGROUND:Compared to older adults with breast cancer (BC), adolescents and young adults (AYAs) develop more aggressive disease necessitating more intensive therapy with curative intent, which is disruptive to planned life trajectories. The burden of unmet needs among AYA BC survivors exists in two domains: (1) symptoms (e.g., sexual problems, anxiety, fatigue, stress, hot flashes) and (2) AYA concerns (e.g., fertility, genetics, relationships, economic attainment). Improved attention to concerns and symptoms may improve symptom management and quality of life. The Young, Empowered and Strong (YES) trial tests the efficacy of a 9-month, multicomponent digital health intervention that includes monthly assessments of prevalent symptoms, a chat room, and journal to engage and support AYAs with BC by providing tailored information, resources, and support outside of the clinical setting. METHODS:YES is a multicenter, randomized controlled trial across three academic institutions in the United States with 400 participants randomized to either the YES intervention or usual care arm. Inclusion criteria include biologically female; 15-39 years of age at diagnosis of stage 0-III BC; within 3 years of diagnosis; no known evidence of recurrence; no prior history of new malignancy since initial BC diagnosis; and ability to access medical records from treatment site. All participants complete REDCap surveys at baseline, and at 3, 6, and 9 months post-enrollment. The primary outcome is quality of life as measured by the Quality of Life in Adult Cancer Survivors Scale (QLACS), with changes from baseline to 6-months in QLACS scores, compared by arm. Secondary outcomes include patient reported AYA concerns/needs, emotional symptoms, general health, physical symptoms, and health behaviors, DISCUSSION: Study findings will provide valuable insight into the ability of the YES digital health intervention to address symptoms and concerns of AYA BC survivors and assist them to track and self-manage their own symptoms, concerns, and needs related to their cancer outside of the clinic. TRIAL REGISTRATION:Clinicaltrials.gov, NCT04906200, registered May 13, 2021.

Limited research has examined the impact of social determinants of health (SDOH) on survivorship care experiences exclusively among Black breast cancer (BC) survivors who face survival disparities due their high prevalence of obesity, comorbidities, and inequities in access and quality of care. Survivorship care experiences among Black BC survivors should be examined to identify potential interventions to improve health outcomes. The goal of this study is to test the feasibility of establishing a state-wide cohort study of Black BC survivors residing in Maryland to address this research gap. This study will recruit 350 Black women BC survivors, aged ≥18 years, and diagnosed with stage I-III primary BC who have completed recommended adjuvant treatment including surgery, chemotherapy, and/or radiation. Recruitment approaches include targeted Facebook ads, outreach to previous study participants, and mailed recruitment letters from the Maryland Cancer Registry (MCR). Participants complete a 30-40-minute online survey, covering demographic and lifestyle factors, clinical and SDOH characteristics, and survivorship care questions. The study also pilots medical record abstractions with the MCR for cancer characteristics and the state designated health-information exchange, Chesapeake Regional Information System for Patients (CRISP), for follow-up care. Recruitment began in July 2024, and by September 2024, 61 self-reported Black participants with a prior diagnosis of BC have completed the survey. The average age at survey is 58.96 (standard deviation (SD)= 11.84)) years, with an average age at diagnosis of 46.42 (SD=13.35) years. 40% are married/living as married, 36.7% are college graduates, all have health insurance, and only 20% reported household incomes <$40, 000/year. Almost half of the survivors self-reported being diagnosed with stage 1 BC (45.9%), followed by 31.1% stage 2, 18% stage 3, and 4.9% unknown stage. The most common self-reported comorbidities include hypertension (39.3%), diabetes (16.7%), and obesity (12.3%). Related to care, 83.3% have a family doctor, and 73.8% received a treatment summary. Additionally, 56.1% and 54.4% consented to medical record linkages with MCR and CRISP, respectively. Recruitment is ongoing. This study will inform future interventions by identifying disparities in survivorship care experiences among Black BC survivors and evaluating the impact of this care on health outcomes. Lensa S. Keno, Camryn Mae Cohen, Kate E. Dibble, Kala Visvanathan, Avonne E. Connor. Social determinants and survivorship care among Black women breast cancer survivors in Maryland [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 6183.

e12562 Background: Previous research has suggested that breast cancer (BC) diagnosed during pregnancy or the postpartum period exhibits more aggressive clinical features, possibly due to pregnancy-related hormonal changes, immune modulation, and alterations in the mammary microenvironment compared to nulligravid or women many years out from pregnancy. Emerging data have demonstrated potential worse outcomes for patients (pts) diagnosed in post-partum. This study evaluated the influence of timing of diagnosis in relation to pregnancy history and recency of childbirth on long-term outcomes in a modern cohort of young pts with early-stage BC. Methods: Pts with stage I–III BC age < 40y in the prospective Young Women’s Breast Cancer Study (YWBCS) were categorized at diagnosis as Nulligravid (no prior pregnancy), Nulliparous (prior pregnancy without live birth), Currently Pregnant, or Parous (subdivided by time since last childbirth: within 5 years [≤ 5y PP], and 5–10 years postpartum [5–10y PP]). Baseline characteristics and outcomes were compared across BC subtypes (estrogen receptor+/HER2- [ER+/HER2-], HER2+, and triple-negative BC [TNBC]). Prognostic analyses for distant recurrence-free survival (DRFS) used Cox models. Results: 859 pts were included, 257 (30%) nulligravid, 50 (6%) nulliparous, 37 (4%) pregnant, and 515 (60%) parous (348 [68%] were ≤5y PP, and 167 [32%] were 5–10y PP). Median follow-up was 133 (6–209) months. Median age at diagnosis was lower in nulligravid pts (33 vs. 35–38 years); T1 tumors were most common in pts >5y PP (62%), and N0 status was highest in nulligravid pts (64%) (all p < 0.0001). Pregnant pts had higher rates of TNBC (27%), and T3 tumors (14%), N1 status, N1 (41%), and Grade 3 (81%) tumors compared to other groups (all p < 0.0001). Overall, only tumor size (T2-T4 vs T1, HR 2.03; 95% CI 1.37–3.03) and nodal status (N1 vs N0, HR 2.22; 1.48–3.34; N2/3 vs N0, HR 3.23; 1.96-5.33) were independently associated with worse DRFS; pregnancy history was not: nulligravid + nulliparous pts had no significant differences in DRFS compared to Pregnant (HR 1.46; 0.75–2.86), Parous <5y PP (HR 0.86; 0.58–1.26), and Parous 5–10y PP (HR 0.89; 0.54–1.48). Subgroup analyses by BC subtype (Table) and sensitivity analyses (excluding currently pregnant pts or separating nulligravid and nulliparous pts) demonstrated no significant associations between pregnancy history and DRFS. Conclusions: In this cohort study of very young patients with early breast cancer with contemporary treatment including management of breast cancer during pregnancy, pregnancy history and recency of pregnancy were not independent predictors of long-term disease outcomes. DRFS results by subgroup. Pregnancy Group N (%) HR (95% CI) ER+/HER2- Nulligravid + Nulliparous 173 (38.1) Ref Pregnant 16 (3.5) 0.93 (0.32–2.70) Parous ≤5y PP 177 (39.0) 0.77 (0.45–1.29) Parous 5–10y PP 88 (19.4) 0.78 (0.39–1.53) HER2+ Nulligravid + Nulliparous 77 (30.8) Ref Pregnant 11 (4.4) 3.27 (0.80–13.38) Parous ≤5y PP 113 (45.2) 1.50 (0.60–3.75) Parous 5–10y PP 49 (19.6) 1.45 (0.45–4.66) TNBC Nulligravid + Nulliparous 56 (36.8) Ref Pregnant 10 (6.6) 1.92 (0.61–6.09) Parous ≤5y PP 57 (37.5) 0.68 (0.28–1.63) Parous 5–10y PP 29 (19.1) 1.16 (0.43–3.14)

1095 Background: Outcomes for patients (pts) with metastatic breast cancer (MBC) have improved with novel antibody drug conjugates like trastuzumab deruxtecan (T-DXd). While T-DXd has been associated with increased risk of alopecia, there are limited data describing the efficacy of scalp cooling in preventing alopecia and improving quality of life among pts receiving T-DXd. Methods: This prospective, phase II study enrolled pts with MBC without alopecia at baseline who were initiating treatment with T-DXd; pts elected to participate in a scalp cooling (SC) arm with the Paxman scalp cooling system or a non-SC arm. The primary endpoint was hair loss, defined as locally assessed CTCAE v5.0 grade ≥1 alopecia occurring at C3D1, C5D1, or end of treatment (EOT), whichever occurred first. The impact of SC on quality of life (QOL) was assessed using the Chemotherapy-Induced Alopecia Distress Scale (CADS) and body image scale (BIS) at baseline, C3D1, C5D1, and EOT. The study aimed to enroll 20 pts per arm to provide at least 80% power to detect a 28% decrease in hair loss rate between the SC vs non-SC arms (8% vs 36%) using a difference in proportions test (one-sided type I error 10%). Results: A total of 40 evaluable pts were enrolled: 20 in SC arm and 20 in non-SC arm. Median age was 61 (33-77); 2 (5%) were Black, 2 (5%) were Hispanic. Twenty-eight (70%) pts had hormone receptor positive disease, 11 (27.5%) HER2+, 2 (5.0%) triple-negative. Thirty-five (87.5%) had prior chemotherapy for MBC; median prior lines was 1 [range: 0-5]. 27 (67.5%) had prior endocrine therapy, 28 (70.0%) had prior CDK4/6 inhibition; 7 (17.5%) had prior use of SC. Thirty-three (82.5%) pts (18 [90%] in SC arm, 15 [75%] in non-SC arm) experienced >grade 1 alopecia, with similar rates observed in both arms (p = 0.41). Grade 2 alopecia was the main reason (45%) for SC discontinuation. Median time to G2 alopecia was 2.76 months (95% CI: 1.64-NA) in SC arm and 4.60 months (95% CI: 2.53, NA) in non-SC arm (p = 0.8). Median CADS scores trended upward from baseline to EOT (Baseline: 3.50; C3: 7.22; C5: 9.00; EOT: 11.5) in the SC arm and were more variable in the non-SC arm (baseline: 3.00; C3: 5.00; C5: 2.56; EOT: 6.50); median BIS scores trended upward in both the SC (baseline: 3.00; C3: 8.00; C5: 9.00; EOT: 11.5) and non-SC arms (baseline: 3.00; C3: 5.00; C5: 5.00; EOT: 9.00), with no statistically significant difference. Conclusions: In this prospective phase II trial, the use of SC with T-DXd did not show a benefit in hair preservation vs no SC. QOL analysis was not significantly different for those receiving SC vs no SC. Small sample size and lack of randomization may limit interpretation of results. Further work is planned to investigate strategies to improve efficacy of SC with ADCs. Clinical trial information: NCT04986579 . CTCAE v5 alopecia. CTCAE v5 Alopecia AllN=40 SC ArmN=20 Non-SC ArmN=20 P-value No alopeciaGrade 1 Grade 2 7(17.5%)11(27.5%)22(55.0%) 2(10.0%)7(35.0%)11(55.0%) 5(25.0%)4(20.0%)11(55.0%) 0.41

We sought to better understand the engagement and interest in topics conveyed via electronic (e-)communications to young adults with breast cancer to inform clinical programming, resource creation, and communication strategy for this patient population. The Young and Strong (Y S) program at Dana-Farber Cancer Institute (DFCI) utilizes Emma©, a HIPAA-compliant communications platform, to create and share e-communications with all patients aged 44 or younger at breast cancer diagnosis, seen at least once at DFCI, including satellite sites. Program faculty and staff curate and contribute relevant clinical and research news, resources, and events, including research opportunities, support groups, webinars, and in-person events. We exploratorily analyzed recipient data using Emma to describe patient engagement with monthly and standalone e-communications from September 2020 to April 2023, including open rates (number opened/number successful deliveries) and click-to-open rates (number clicks/number opened). An average of 3915 young patients were emailed monthly e-communications (range 3202–4380). The open rate steadily increased from 19.3 to 53.0

Introduction: Although young adults (YA) aged 18-39 represent the minority of breast cancer diagnoses, they are particularly vulnerable to financial hardship. Factors contributing to sustained financial hardship are incompletely understood. Arm morbidity, one such understudied factor and key source of expense, may be particularly salient for YAs given that a high proportion of this demographic presents with aggressive tumor subtypes requiring comprehensive axillary management (a known risk factor for treatment-related lymphatic injury). In this study, we leverage a multi-institutional prospective cohort of YAs to identify patterns of financial hardship over time and characterize factors associated with discrete trajectories hypothesizing that treatment-related arm morbidity would be among the factors predicting long-term financial difficulty. Methods: This analysis utilized data from women ≤ 40 years with newly diagnosed stage 0 to III breast cancer enrolled in The Young Women’s Breast Cancer Study (YWS), a multi-institutional prospective cohort study enrolling from 2006 and 2016 at Dana-Farber Cancer Institute and 12 other academic and community hospitals in the United States and Canada. Patient, disease, and treatment information was obtained from surveys serially collected through 10 years post-diagnosis. Arm morbidity was assessed by asking patients about the degree to which they experienced upper extremity swelling and/or functional limitations using two Likert-scale response items (range: 0-4). Medical record review was used to gather supplemental clinical data. The primary outcome of interest, perceived financial difficulty, was assessed serially using a single Likert-scale response item (range: 0-4) from the CAncer Rehabilitation Evaluation System (CARES) scale. Group-based trajectory modeling classified patterns of financial difficulty from baseline through 10 years post-diagnosis. Multinomial logistic regression identified patient, disease, and treatment characteristics associated with each trajectory. Results: 1008 (78%) of 1297 participants were included. Median age at diagnosis was 36 years (IQR 33-39). The majority of individuals were non-Hispanic (95%), White (88%), college graduates (83%), partnered at baseline (76%), parous (64%), and without comorbidities at enrollment (90%). Patients’ tumors were primarily stage I-II (86%), ER/PR-positive (75%), and HER2-negative (68%). Patients were more frequently treated with mastectomy than breast conservation (p<0.001). Receipt of radiation (62%), chemotherapy (75%), and endocrine therapy (63%) were common. 72% (N=727) of patients reported arm symptoms within 2 years of surgery. Three distinct financial trajectories emerged: 54% had low financial difficulty (Trajectory 1), 30% had mild difficulty that improved (Trajectory 2), and 17% had moderate/severe difficulty peaking several years after diagnosis before improving (Trajectory 3). BMI ≥ 25, undergoing bilateral mastectomy, Hispanic ethnicity, being unemployed at both baseline and 1 year, and arm symptoms were predictive of Trajectory 2 and/or 3 (more financial difficulty). Having a college degree or being partnered were predictive of Trajectory 1 (low financial difficulty). CONCLUSION: This study of YAs with breast cancer identified a subset of patients who experienced a high degree of financial difficulty that persisted into early survivorship before it improved. Targeted interventions to mitigate financial toxicity, including those focused on modifiable factors such as arm symptoms and employability/return to work after cancer, are needed. Citation Format: Sara Myers, Yue Zheng, Kate Dibble, Elizabeth A. Mittendorf, Tari A. King, Kathryn J. Ruddy, Jeffrey M. Peppercorn, Lidia Schapira, Virginia F. Borges, Steven E. Come, Shoshana M. Rosenberg, Ann H. Partridge. Financial difficulty over time in young adults with breast cancer [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2024; 2024 Dec 10-13; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2025;31(12 Suppl):Abstract nr PS5-07.

537 Background: There is no evidence regarding the benefit of extended endocrine therapy (eET) beyond 5 years of adjuvant treatment with LHRH agonists (LHRHa) in premenopausal women with node-positive, HR-positive early breast cancer (eBC). Methods: We conducted a retrospective study on two prospectively maintained datasets (Young Women Study and IEO Breast Cancer Dataset) to evaluate the clinical benefit of eET in women who had completed 5 years of adjuvant LHRHa, remained premenopausal, and had no evidence of distant or locoregional recurrence. This study included <40y women at diagnosis (between 2006 and 2016) with node-positive HR+ eBC, with ductal, lobular, or mixed histological subtypes, receiving or not eET (tamoxifen monotherapy or LHRHa+tamoxifen/aromatase inhibitor [AI]). The primary endpoint was the invasive breast cancer-free survival (IBCFS), calculated from the 5th year of endocrine therapy (ET) and adjusted for dataset, age at diagnosis, histotype, stage, disease subtype, type of adjuvant chemotherapy and ET received. Results: 503 patients were included (see Table): 287 received eET for a median duration of 3.6 years (Interquartile Range: 2.1–5.0). At a median follow-up of 7.05 years (calculated from the 5th year of ET), 50 and 72 IBCFS events occurred in the eET and non-eET groups, respectively. The adjusted Hazard Ratio (HR) for IBCFS comparing the eET to the non-eET group was 0.60 (95% CI,0.41-0.88; p<0.001). For distant recurrence or death, 28 and 46 events occurred, respectively, and the adjusted HR for distant disease free-survival was 0.43 (95% CI, 0.27-0.71). Among patients receiving eET, the adjusted HR for IBCFS comparing tamoxifen monotherapy (n=137) with LHRHa+tamoxifen/AI (n=150) was 0.75 (95% CI, 0.41-1.38). Conclusions: Extending endocrine therapy beyond five years of LHRHa treatment resulted in significantly higher IBCFS and distant metastasis free-survival. Larger prospective studies are required to confirm this finding and determine the most effective eET strategy. Patients' characteristics. Characteristic Extended endocrine therapy(N=287) No extended endocrine therapy(N=216) Age at diagnosis, median (IQR) 37 (35-39) 37 (33-39) Dataset: IEO | YWS, n 273 | 14 212 | 4 Histotype: ductal | lobular | mixed, % 91 | 5 | 4 95 | 3 | 2 pT: pT1 | pT2 | pT3-4, % 37 | 48 | 15 41 | 52 | 7 pN: pN1 | pN2 | pN3, % 64 | 22 | 14 73 | 17 | 10 Luminal A-like | B-like (G3 or HER2+), % 47 | 53 49 | 51 LHRHa combination during years 1-5: tamoxifen | aromatase inhibitor, % 66 | 34 76 | 22 Previous chemotherapy, % 77 70 Previous radiotherapy, % 64 62 G3, grade 3; IEO, European Institute of Oncology; IQR, interquartile range; YWS, Young Women Study.

This study examined potential disparities in Consumer Assessment of Healthcare Providers and Systems (CAHPS) scores of patient care experiences among racial/ethnic minority survivors and breast cancer-specific mortality. Female breast cancer survivors who completed a CAHPS survey between 2000 and 2019 after being diagnosed with first primary invasive breast cancer were selected from the Surveillance, Epidemiology, and End Results (SEER)-CAHPS data linkage. Adjusted Fine-Gray subdistribution hazards models were used to determine associations of CAHPS scores of patient care experiences with breast cancer-specific mortality, overall and stratified by race/ethnicity. Most survivors were NHW women (80.4 percent). Adjusted associations between CAHPS scores and breast cancer mortality were not significant. However, Hispanic survivors reporting higher Physician Rating scores were less likely to experience breast cancer death (HR = 0.985, 95 percent CI = 0.970-1.000, p = .046). The only interaction found to be significant was observed among other/multi-racial groups and Getting Care Quickly (p = .044). Patient care experience scores were not associated with breast cancer-specific mortality among older breast cancer survivors; some associations were found to be significant among certain racial/ethnic groups. Future research should capture care experiences from historically underrepresented populations.

Background: Breast cancer (BC) diagnosed in the postpartum period has been associated with a worse prognosis compared to nulligravid patients (pts), possibly due to differences in carcinogenesis associated with prior pregnancies. Persistent changes in gene expression, structural composition, immune microenvironment, and epigenetic modifications within the mammary gland have been observed following pregnancy. Oncotype DX Breast Recurrence Score® test is a gene expression profile that has been incorporated into the management of early-stage, estrogen receptor-positive (ER+), HER2-negative (HER2-) BC as a prognostic and predictive biomarker of chemotherapy effect. However, there are limited data on the impact of previous pregnancies on the expression of the 21 genes analyzed in the Oncotype DX® test and on the prognostic accuracy of this assay. The aim of this study is to evaluate the influence of pregnancy status on the distribution of Recurrence Score® (RS) results and long-term outcomes of young pts with early-stage, ER+, HER2- BC. Methods: Pts with stage I-III, ER+, HER2- BC were classified as “nulligravid” or “postpartum” based on the absence or presence of pregnancy history prior to BC diagnosis from the Young Women’s Breast Cancer Study, a prospective cohort that enrolled women with BC diagnosed at age ≤ 40 years between 2006 and 2016. Pts whose BC was diagnosed during pregnancy were excluded. RS was obtained from banked samples when not clinically performed. RS was categorized as low (< 11), intermediate (11-25), or high (> 25). Multivariable Cox hazards models were used to assess factors associated with distant recurrence-free interval (DRFI). Results: Among 387 included pts, 117 (30.2%) were nulligravid and 270 (69.8%) postpartum. Median time from last pregnancy was 4.72 years (range 0.96 – 21.84) for the postpartum group. Median age at diagnosis was 34 and 37 years, N+ rate was 28 (24.0%) and 118 (43.7%), and chemotherapy was administered to 74 (63.3%) and 202 (74.8%) of nulligravid and postpartum pts, respectively. The median RS was 17 (range: 3-66) for nulligravid pts and 21 (4 – 77) for postpartum pts (p=0.004). The proportion of pts with low, intermediate and high RS was 16 (13.68%), 76 (64.96%) and 25 (21.37%) in nulligravid pts; and 28 (10.37%), 157 (58.15%) and 85 (31.48%) in postpartum (p=0.11). Among pts with N0 BC, 11-year DRFI rates were 91.7 (95% CI: 53.9 - 98.8), 90.7 (79.1 - 96.0), and 83.0 (55.9 - 94.2) for pts with RS < 11, RS 11-25, and RS > 25 for nulligravid women, and 83.3 (48.2 - 95.6), 92.0 (82.8 - 96.4), and 77.6 (61.3 - 87.7) for postpartum, respectively. Among pts with N+ BC, 11-year DRFI rates were 100.0, 76.2 (48.1 - 90.4), and 57.1 (17.2 - 83.7) for pts with RS < 11, RS 11-25, and RS > 25 for nulligravid women, and 79.4 (48.8 - 92.9), 71.1 (57.6 - 80.9), and 75.6 (59.1 - 86.2) for postpartum pts, respectively. In multivariable model of pts with N0 or N1-3 nodes, adjusting for RS, T-stage, N-stage, pregnancy status, and chemotherapy use, only RS (HR 1.02 per 1 point increase, 95%CI 1.002-1.039), T-stage (HR 2.01, 95%CI 1.11-3.65), and N-stage (HR 1.83, 95%CI 1.01-3.31) were independently associated with DRFI. Conclusion: Pts diagnosed with BC in the postpartum period had higher RS results compared to nulligravid women. After adjusting for stage and RS, previous pregnancy status was not associated with worse long-term outcomes in young women with node negative or 1-3 node positive ER+ breast cancer. While further analyses incorporating time since last pregnancy will be conducted, these data suggest inferior outcomes observed in these patients may be in part related to higher genomic risk tumors. Citation Format: Guilherme Nader-Marta,Yue Zheng, Kate E. Dibble, Shoshana M. Rosenberg, Erica L. Mayer, Philip D. Poorvu, Kathryn J. Ruddy, Laura C. Collins, Jeffrey Peppercorn, Lidia Schapira, Virginia F. Borges, Christy A. Russell, Steven E. Come, Ellen Warner, Kornelia Polyak, Eric P. Winer, Ann H. Partridge. Oncotype DX Breast Recurrence Score® distribution and prognostic value according to prior pregnancy status in young women with breast cancer [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2024; 2024 Dec 10-13; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2025;31(12 Suppl):Abstract nr P1-01-23.

Survivorship care plans (SCPs) support the transition from oncology to follow-up care, yet limited research exists on SCP use among Black breast cancer (BC) survivors. To address this gap, we are recruiting Maryland-based BC survivors to study SCP use, care experiences, and associations with social determinants of health (SDOH). Our qualitative aim will assess SCP knowledge and primary care needs among 30 Black BC survivors via in-depth interviews. This preliminary analysis compares SDOH factors between those who declined and agreed to be contacted to participate in the qualitative study. Black women BC survivors who consented to be recontacted for a Zoom interview during our baseline online research survey will be recruited. Eligible participants for the online survey and interview are adult Black women in Maryland, diagnosed with stage I–III primary BC, and who have completed BC treatments. Qualitative interviews will be conducted with up to 30 participants, ensuring diversity by age, time since diagnosis, and county. For this preliminary analysis, descriptive statistics were used to compare demographics and SDOH of those who declined and agreed to being contacted for interview participation. As of June 2025, 95 participants completed the baseline survey, 62 (65.2%) agreed to be recontacted for an interview, while 33 (34.7%) declined. Among decliners, the mean ages at time of the survey and at diagnosis were 58 years (standard deviation [SD] = 10) and 47 years (SD = 12.9), respectively. Among those who agreed, the mean ages at survey and diagnosis were 59 (SD = 12.2) and 50 years (SD = 12), respectively. In relation to income, 17.8% of decliners and 25.4% of those who agreed reported annual household incomes <$40,000. Decliners were more likely to have private insurance compared to those who agreed (56.3% vs. 49.2%) and higher rates of being high school graduates (15.6% vs. 4.8%), but lower rates of completing college (28.1% vs. 38.7%). Perceptions of neighborhood safety also differed with fewer decliners reporting feeling extremely safe (12.5% vs. 22.6%). There were no differences in transportation access, with most participants in both groups reporting driving themselves to medical appointments (81.3% vs. 82.3%). Reports on job discrimination were more common among decliners (62% vs. 54.8%), as were challenges affording balanced meals (15.6% vs. 13.1%). A greater proportion of decliners received most of their care from a primary care provider (87.5% vs. 75.8%) and received an SCP (100% vs. 93%). While developing our qualitative study, we found that women who declined to be recontacted for participation faced some adverse SDOH, including lower education, neighborhood safety, job discrimination, and difficulty affording balanced meals. Our future studies will evaluate more targeted strategies to include the voices of women impacted by social disadvantage and structural barriers. Lensa S. Keno, Kate E. Dibble, Katherine Clegg-Smith, Kala Visvanathan, Avonne E. Connor. Designing a qualitative study on survivorship care experiences among Black women breast cancer survivors in Maryland [abstract]. In: Proceedings of the 18th AACR Conference on the Science of Cancer Health Disparities; 2025 Sep 18-21; Baltimore, MD. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2025;34(9 Suppl):Abstract nr B100.