Snow, Craig

Abstract 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.

Abstract Background The incidence of early onset breast cancers (BCs) has increased, paralleling rising trends in delayed childbearing. We hypothesize that a distinct postpartum BC (PPBC) subtype, identifiable by time since last birth (TSLB) and biomarker expression, contributes to this trend. Methods We applied GeoMx Digital Spatial Profiling (DSP) to measure associations between TSLB and 71 proteins in 640 BCs from women aged ≤40 years included in the Young Women’s Breast Cancer Study. We analyzed data using univariable linear regression and multivariable sliced inverse regression to account for higher order interactions among biomarkers. Results In keratin-rich segments, progesterone receptor (PR) (P = 1.00 × 10−4) and PTEN (P = 1.00 × 10−3) were associated with longer TSLB; multivariable analyses revealed positive associations for GZMB (P = 4.00 × 10−4), SMA (P = 1.00 × 10−4), and NF-1 (P = 1.00 × 10−3). In keratin-poor segments, univariable significant positive associations were found for PR (P = 2.00 × 10−4) and PTEN (P = 1.00 × 10−3), whereas CD20 (P = 3.00 × 10−4) and CTLA4 (P = 4.00 × 10−5) were negatively associated; multivariable significant associations were found for fibronectin (P = 3.00 × 10−5) and pan-Akt (P = 1.00 × 10−3). Associations persisted after adjustment for multiple comparisons and BC molecular subtypes. Associations including for PR, PTEN, and CD20 were strongest among women with the shortest TSLB. OPAL multiplex immunofluorescence assays for PR, PTEN, CD20, SMA, and CTLA4 replicated several DSP findings, particularly when stratified by subtype and with compartment matching. In TCGA, RNA species linked to proteins associated with TSLB correlated strongly with a T-cell exhaustion signature previously linked to poor prognosis among premenopausal women. Conclusion These data support PPBC as a biologically coherent phenotype defined by TSLB and biomarker profile, with potential implications for prevention and therapy.

Abstract Purpose: The role of tumor-infiltrating lymphocytes (TIL) remains unclear in hormone receptor (HR)–positive/HER2-negative breast cancer, particularly in young patients, whose immune microenvironment could be altered by age-related host and tumor differences. Experimental Design: Patients with stage I to III HR-positive/HER2-negative tumors were identified from a prospective cohort study of patients with breast cancer diagnosed at age ≤40 years. Multiplexed immunofluorescence and semiautomated quantitative software measured cytotoxic T, non–CD8 T, T regulatory, exhausted T, and PDL1+ cells in stroma and tumor. Univariate analyses assessed differences in clinicopathologic characteristics by high versus low immune infiltration, divided based on median. TIL subtypes were evaluated as a continuous variable per 10% increase in Cox regression analyses for invasive breast cancer–free survival, distant disease–free survival (DDFS), and overall survival, adjusted for clinicopathologic parameters. Results: Among 390 patients, high immune infiltration was associated with increasing age, Black race, grade 3 tumors, and metaplastic or micropapillary histologic subtypes. Over a median follow-up of 8 years, higher stromal and intratumoral non–CD8 T-cell infiltration, T regulatory–cell infiltration, and PDL1 expression were associated with improved invasive breast cancer–free survival. Higher intratumoral non–CD8 T-cell infiltration, T regulatory–cell infiltration, and PDL1 expression were associated with improved DDFS; higher stromal PDL1 expression was also associated with improved DDFS. Higher intratumoral cytotoxic T-cell infiltration and PDL1 expression were associated with improved overall survival. Conclusions: Characterization of immune subpopulations could help refine the prognostic value of TILs in young patients with HR-positive breast cancer, who may benefit from risk stratification for treatment individualization. See related commentary by Salgado and Kok, p. 2133

ABSTRACTBackgroundFollowing breast cancer (BC), many young women are interested in future childbearing and some may wish to breastfeed. However, limited information is available regarding their lactation experiences.MethodsParticipants in the Young Women's Breast Cancer Study, a multicenter, prospective cohort study of women ≤40 years diagnosed with stage 0–III BC between 2006–2016 and who reported one or more live births following diagnosis, were surveyed about pregnancy and breastfeeding after BC treatment, including reasons for attempting and stopping breastfeeding, satisfaction, and supports.ResultsOf 143 eligible women sent a survey, 115 responded and 94 were included in the analytic cohort. Breastfeeding was attempted by 55% of women (52 of 94). Among those who had not attempted, 93% noted prior bilateral mastectomies (39 of 42). Among those who attempted breastfeeding, 69% had undergone lumpectomy and radiotherapy (36 of 52), 83% of whom reported no milk production from their treated breast (30 of 36). Most (65%, 34 of 52) were at least somewhat satisfied with their ability to breastfeed. Reasons for stopping breastfeeding included: having completed the planned duration (36%, 19 of 52); to start/resume endocrine therapy (21%, 11 of 52); and to resume breast imaging (8%, 4 of 52). Approximately half (27 of 55) of women who had not undergone bilateral mastectomies recalled receiving specific information about breastfeeding after BC, mostly from the oncology team (59%, 16 of 27), online resources (48%, 13 of 27), or a lactation consultant (44%, 12 of 27).ConclusionMost young BC survivors who attempted to breastfeed were able to and were satisfied with the experience, despite challenges. Specific resources to support BC survivors who wish to breastfeed are needed.

Abstract Background. Approximately 12,000 women aged 40 years or younger are diagnosed with breast cancer every year in the United States alone. Limited data exist regarding survival in young women with metastatic breast cancer (MBC), particularly when considering modern tumor subtyping and treatment, though previous studies have suggested that patients presenting with MBC at diagnosis (de novo stage IV) have better prognosis than those who develop recurrent MBC after initial diagnosis of stage 0-III disease. We sought to determine survival rates in young patients with MBC stratified by disease presentation (de novo versus recurrent) and subtype. Methods. The Young Women’s Breast Cancer Study (YWS) is a multicenter, prospective cohort which enrolled 1,302 women diagnosed with stage 0-IV breast cancer at age ≤40 from 13 North American academic and community-based sites from 2006-2016. The current median follow-up is 10.1 (range 0.4-16.3) years. Histopathology slides were centrally reviewed for 97% of the participants, and clinical tumor molecular subtypes have been detailed. In the recurrent group, receptors were obtained from the initial breast surgery. Descriptive analyses were used to characterize patients with de novo or recurrent MBC, including demographic and disease characteristics, and survival rates. Overall survival was estimated using the Kaplan-Meier method and compared by log-rank test between those who presented with de novo and relapsed disease overall and within tumor subtypes. Results. Among 246 patients included in this analysis, 74.0% (n=182) had recurrent MBC and 26.0% (n=64) had de novo MBC. Most patients were white (n=208, 84.6%), while 6.9% were Asian (n=17), 4.5% Black (n=11), 0.8% Native American (n=2), 0.8% multiracial (n=2) and 2.4% other/unknown (n=6). A total of 4.5% of patients were Hispanic (n=11). Median age at diagnosis of de novo MBC was 37 years and 40 years for diagnosis of metastasis in the recurrent group. Median disease-free interval was 3.23 (range 0.32 – 13.84) years for the recurrent MBC group. Among all patients with MBC, most (55.7%, n=137) had estrogen receptor (ER) and/or progesterone receptor (PR)-positive, human epidermal growth factor receptor 2 (HER2)-negative disease, whereas 17.9% (n=44) had ER and/or PR-positive HER2-positive, 7.3% (n=18) had ER/PR-negative HER2-positive, and 18.7% (n=46) had triple-negative tumors. A greater proportion of participants (43.8%, n=28) had HER2-positive disease in the de novo group than in the recurrent group (18.7%, n=34), P=< 0.0001. A total of 10.9% (n=7) of de novo patients had a germline BRCA mutation, compared to 13.7% (n=25) in the recurrent group. Median survival was 5.09 (95% CI: 3.74 – 6.38) years in the de novo group and 2.63 (95% CI: 1.98 – 3.21) years in the recurrent MBC group (P=0.0004). When stratifying by subtype, survival among patients with de novo ER and/or PR-positive HER2-positive disease was longer than among patients with recurrent disease (P=0.0149), whereas there were no statistically significant differences in survival between the de novo and recurrent disease groups in other disease subtypes (Table 1). Conclusion. Survival in young women with MBC is highly heterogeneous and varies substantially by tumor subtype and disease presentation. Those with de novo ER and/or PR-positive HER2-positive subtype appear to have better outcomes than those with recurrent MBC with the same subtype. These findings can inform patient care and potential future research to improve outcomes for young patients with MBC. Table 1: Median survival by disease presentation and subtype * 1 patient with recurrent MBC was not included because the initial diagnosis was DCIS MBC: metastatic breast cancer; OS: overall survival; CI: confidence interval; ER: estrogen receptor; PR: progesterone receptor; HER2: human epidermal growth factor receptor 2 Citation Format: Leticia Varella, Yue Zheng, Shoshana Rosenberg, Gregory Kirkner, Craig Snow, Kathryn Ruddy, Rulla Tamimi, Jeffrey Peppercorn, Lidia Schapira, Virginia Borges, Steven Come, Laura Collins, Ellen Warner, Kate Dibble, Eric Winer, Ann Partridge. Survival in Young Women with De Novo or Recurrent Metastatic Breast Cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-05-14.

Abstract Background. Breast cancer (BC) is the leading cause of cancer-related death in young women worldwide, and late recurrence of hormone receptor-positive disease plays a substantial role. Adjuvant endocrine therapy with 5 years of ovarian function suppression (OFS) and an aromatase inhibitor or tamoxifen is recommended for many young patients with high risk hormone receptor-positive BC. Data are limited regarding extended endocrine therapy among premenopausal BC survivors, and non-existent to inform treatment decisions regarding extending OFS beyond 5 years. We sought to evaluate young BC survivors’ perceptions and preferences regarding extending OFS beyond 5 years, and consideration of a potential future study to assess the role of extended OFS. Methods. From January-April 2023, email invites were sent to the Young Survival Coalition (YSC) listserv (N=14,291) specifically asking members with a history of invasive BC (≤45 years at diagnosis; stage I-III without metastatic recurrence) receiving OFS injections for adjuvant endocrine treatment to complete a one-time anonymous online survey. The survey was designed to capture information regarding current endocrine therapy use, patient-provider communication regarding extended endocrine therapy including OFS, OFS-related concerns (rating 0-5 [low: 0-1, moderate: 2-3, severe: 4-5]), and interest in a potential future clinical trial utilizing OFS beyond 5 years. Descriptive statistics were utilized to summarize responses, and two-sided Fishers exact tests and chi-square analyses were used for comparisons. Results. A total of 1,030 YSC members completed the survey, and 615 were analyzed due to eligibility and completeness of data. The majority were from the United States (n=579, 94.1%) or Canada (n=8, 1.3%), were non-Hispanic white (n=452, 73.5%), non-Hispanic Black (n=46, 7.5%), or Hispanic (n=43, 7.0%), and had been diagnosed with stage II BC (n=316, 51.4%). The average age at survey was 38.1 years (SD=5.15, range=22-54) and at initial BC diagnosis was 34.6 years (SD=4.96, range=20-49). Most (n=510, 83.0%) were within their first 5 years of OFS treatment while 14.5% (n=89) had already been receiving OFS for more than 5 years. Many respondents (n=344, 55.9%) reported discussing OFS use beyond 5 years with their provider, of whom 39.8% (n=245) reported their provider recommending they continue OFS for more than 5 years. Despite reporting moderate and severe concerns regarding OFS side effects (n=476, 77.4%), inconvenience of injection visits (n=272, 44.2%), and high cost of medication (n=223, 36.3%), most respondents (n=396, 64.4%) would consider continuing OFS beyond 5 years if it would reduce risk of BC recurrence. For nearly half of respondents (n=289, 47.0%) a risk reduction of at least 5% would be required for extended OFS to be worthwhile compared to the remaining 46.3% (n=285) who indicated interest for < 5% risk reduction. When asked hypothetically if they would take part in a clinical trial to determine efficacy of OFS use beyond 5 years, the majority were interested (n=357, 58.0%). Respondents who were interested were less likely to be concerned about the high cost of medication (p=0.003) however they were also less likely to take OFS beyond 5 years if it only led to 1-2% BC risk reduction (p=0.006) compared to those who were not interested. There were no other proportional differences on any other outcome. Conclusion. Many BC survivors and providers are already considering incorporation of OFS beyond 5 years into adjuvant endocrine therapy despite harboring concerns and lack of data. Efforts to determine the efficacy and benefits of extended OFS are necessary given the risk of late recurrence in this population as well as the potential for significant short- and long-term toxicities. The results from this survey study suggest that future clinical trials evaluating potential benefits and risks of long-term OFS use among young BC survivors are needed and likely feasible. Citation Format: Kate Dibble, Tal Sella, Kathryn Ruddy, Craig Snow, Amanda Nixon, Patricia Spears, Karla Ballman, Lisa Carey, Ann Partridge. Ovarian function suppression (OFS) use beyond five years?: Young breast cancer patient preferences [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-01-11.

Importance Among women diagnosed with primary breast cancer (BC) at or younger than age 40 years, prior data suggest that their risk of a second primary BC (SPBC) is higher than that of women who are older when they develop a first primary BC. Objective To estimate cumulative incidence and characterize risk factors of SPBC among young patients with BC. Design, Setting, and Participants Participants were enrolled in the Young Women’s Breast Cancer Study, a prospective study of 1297 women aged 40 years or younger who were diagnosed with stage 0 to III BC from August 2006 to June 2015. Demographic, genetic testing, treatment, and outcome data were collected by patient surveys and medical record review. A time-to-event analysis was used to account for competing risks when determining cumulative incidence of SPBC, and Fine-Gray subdistribution hazard models were used to evaluate associations between clinical factors and SPBC risk. Data were analyzed from January to May 2023. Main Outcomes and Measures The 5- and 10- year cumulative incidence of SPBC. Results In all, 685 women with stage 0 to III BC (mean [SD] age at primary BC diagnosis, 36 [4] years) who underwent unilateral mastectomy or lumpectomy as the primary surgery for BC were included in the analysis. Over a median (IQR) follow-up of 10.0 (7.4-12.1) years, 17 patients (2.5%) developed an SPBC; 2 of these patients had cancer in the ipsilateral breast after lumpectomy. The median (IQR) time from primary BC diagnosis to SPBC was 4.2 (3.3-5.6) years. Among 577 women who underwent genetic testing, the 10-year risk of SPBC was 2.2% for women who did not carry a pathogenic variant (12 of 544) and 8.9% for carriers of a pathogenic variant (3 of 33). In multivariate analyses, the risk of SPBC was higher among PV carriers vs noncarriers (subdistribution hazard ratio [sHR], 5.27; 95% CI, 1.43-19.43) and women with primary in situ BC vs invasive BC (sHR, 5.61; 95% CI, 1.52-20.70). Conclusions Findings of this cohort study suggest that young BC survivors without a germline pathogenic variant have a low risk of developing a SPBC in the first 10 years after diagnosis. Findings from germline genetic testing may inform treatment decision-making and follow-up care considerations in this population.

Immune escape is a prerequisite for tumor growth. We previously described a decline in intratumor activated cytotoxic T cells and T cell receptor (TCR) clonotype diversity in invasive breast carcinomas compared to ductal carcinoma in situ (DCIS), implying a central role of decreasing T cell responses in tumor progression. To determine potential associations between peripheral immunity and breast tumor progression, here, we assessed the peripheral blood TCR clonotype of 485 breast cancer patients diagnosed with either DCIS or de novo stage IV disease at younger (<45) or older (≥45) age. TCR clonotype diversity was significantly lower in older compared to younger breast cancer patients regardless of tumor stage at diagnosis. In the younger age group, TCR-α clonotype diversity was lower in patients diagnosed with de novo stage IV breast cancer compared to those diagnosed with DCIS. In the older age group, DCIS patients with higher TCR-α clonotype diversity were more likely to have a recurrence compared to those with lower diversity. Whole blood transcriptome profiles were distinct depending on the TCR-α Chao1 diversity score. There were more CD8 + T cells and a more active immune environment in DCIS tumors of young patients with higher peripheral blood TCR-α Chao1 diversity than in those with lower diversity. These results provide insights into the role that host immunity plays in breast cancer development across different age groups.

AbstractBackgroundBreast cancer (BC) is the most common malignancy in women of reproductive age. This study sought to explore the postcancer conception and pregnancy experience of young BC survivors to inform counseling.MethodsIn the Young Women's Breast Cancer Study (NCT01468246), a multicenter, prospective cohort, participants diagnosed at age ≤40 years with stage 0‐III BC who reported ≥1 postdiagnosis live birth were sent an investigator‐developed survey.ResultsOf 119 eligible women, 94 (79%) completed the survey. Median age at diagnosis was 32 years (range, 17–40) and at first postdiagnosis delivery was 38 years (range, 29–47). Most had stage I or II (77%) and HR+ (78%) BC; 51% were nulligravida at diagnosis. After BC treatment, most (62%) conceived naturally, though 38% used assisted reproductive technology, 74% of whom first attempted natural conception for a median of 9 months (range, 2–48). Among women with a known inherited pathogenic variant (n = 20), two underwent preimplantation genetic testing. Of 59 women on endocrine therapy before pregnancy, 26% did not resume treatment. Hypertensive disorders of pregnancy (20%) was the most common obstetrical condition. Nine percent of newborns required neonatal intensive care unit admission and 9% had low birth weight.ConclusionAmong women with live births after BC treatment, most conceived naturally and having a history of BC did not appear to negatively impact pregnancy complications, though the high rate of hypertensive disorders of pregnancy warrants further investigation. The prolonged period of attempting natural conception for some survivors suggests the potential need for improved understanding and counseling surrounding family planning goals after BC.

PURPOSE Erb-B2 receptor tyrosine kinase 2 ( ERBB2)–positive breast cancer (BC) is particularly common in young women. Genomic features of ERBB2-positive tumors before and after chemotherapy and trastuzumab (chemo + H) have not been described in young women and are important for guiding study of therapeutic resistance in this population. METHODS From a large prospective cohort of women age 40 years or younger with BC, we identified patients with ERBB2-positive BC and tumor tissue available before and after chemo + H. Whole-exome sequencing (WES) was performed on each tumor and on germline DNA from blood. Tumor-normal pairs were analyzed for mutations and copy number (CN) changes. RESULTS Twenty-two women had successful WES on samples from at least one time point; 12 of these had paired sequencing results from before and after chemo + H and 10 had successful sequencing from either time point. TP53 was the only significantly recurrently mutated gene in both pre- and post-treatment samples. MYC gene amplification was observed in four post-treatment tumors. Seven of 12 patients with paired samples showed acquired and/or clonally enriched alterations in cancer-related genes. One patient had an increased clonality putative activating mutation in ERBB2. Another patient acquired a clonal hotspot mutation in TP53. Other genomic changes acquired in post-treatment specimens included alterations in NOTCH2, STIL, PIK3CA, and GATA3. There was no significant change in median ERBB2 CN (20.3 v 22.6; Wilcoxon P = .79) between paired samples. CONCLUSION ERBB2-positive BCs in young women displayed substantial genomic evolution after treatment with chemo + H. Approximately half of patients with paired samples demonstrated acquired and/or clonally enriched genomic changes in cancer genes. ERBB2 CN changes were uncommon. We identified several genes warranting exploration as potential mechanisms of resistance to therapy in this population.