Partridge, Ann H.

PURPOSE We investigated time to pregnancy, efficacy and safety of fertility preservation, and assisted reproductive technologies (ARTs) in women with early hormone receptor–positive breast cancer (BC) desiring future pregnancy. PATIENTS AND METHODS POSITIVE is an international, single-arm, prospective trial, in which 518 women temporarily interrupted adjuvant endocrine therapy to attempt pregnancy. We evaluated menstruation recovery and factors associated with time to pregnancy and investigated if ART use was associated with achieving pregnancy. The cumulative incidence of BC-free interval (BCFI) events was estimated according to the use of ovarian stimulation at diagnosis. The median follow-up was 41 months. RESULTS Two hundred seventy-three patients (53%) reported amenorrhea at enrollment, of whom 94% resumed menses within 12 months. Among 497 patients evaluable for pregnancy, 368 (74%) reported at least one pregnancy. Young age was the main factor associated with shorter time to pregnancy with cumulative incidences of pregnancy by 1 year of 63.5%, 54.3%, and 37.7% for patients age <35, 35-39, and 40-42 years, respectively. One hundred and seventy-nine patients (36%) had embryo/oocyte cryopreservation at diagnosis, of whom 68 reported embryo transfer after enrollment. Cryopreserved embryo transfer was the only ART associated with higher chance of pregnancy (odds ratio, 2.41 [95% CI, 1.75 to 4.95]). The cumulative incidence of BCFI events at 3 years was similar for women who underwent ovarian stimulation for cryopreservation at diagnosis, 9.7% (95% CI, 6.0 to 15.4), compared with those who did not, 8.7% (95% CI, 6.0 to 12.5). CONCLUSION In POSITIVE, fertility preservation using ovarian stimulation was not associated with short-term detrimental impact on cancer prognosis. Pregnancy rates were highest among those who underwent embryo/oocyte cryopreservation followed by embryo transfer.

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=&lt; 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: Patients with HER2+ early breast cancer (EBC) and invasive residual disease (RD) after neoadjuvant therapy (NAT) have a higher risk of relapse than patients who have a pathologic complete response (pCR). Escalation of therapy in patients with RD using post-neoadjuvant T-DM1 has become the new standard of care, leading to improved invasive disease-free survival (iDFS), but patients with estrogen receptor (ER)-negative or nodal RD have suboptimal outcomes, and central nervous system recurrences are a challenge. More effective treatment strategies are urgently needed. Alliance A011801 (CompassHER2 RD) is an escalation trial for patients with high-risk HER2+ RD after neoadjuvant systemic therapy, evaluating the addition of the HER2 selective tyrosine kinase inhibitor (TKI) tucatinib to post-neoadjuvant T-DM1. Methods: Eligibility and Intervention: Patients with high-risk HER2+ RD (i.e., ER-, node-positive, or both) after a predefined course of neoadjuvant HER2-directed treatment are randomized 1:1 to adjuvant T-DM1 + placebo, vs. T-DM1 and tucatinib with adjuvant RT +/- ET. Eligibility criteria include completion of ≥ 6 cycles of NAT, including ≥ 9 weeks of paclitaxel and trastuzumab +/- pertuzumab. All chemotherapy (CT) must be completed preoperatively unless participating in EA1181 (~15-30% will be participants in the CompassHER2 pCR de-escalation companion trial [NCT04266249]; these patients must receive postoperative CT to complete ≥ 6 cycles prior to enrollment on A011801). Patients who received prior HER2-targeted TKIs or antibody-drug conjugates are ineligible. Objectives: The primary objective is to determine if iDFS is improved with addition of tucatinib to T-DM1 in patients with HER2+ EBC with RD after neoadjuvant systemic therapy; secondary endpoints include overall survival, breast cancer free survival, distant recurrence-free survival, brain metastases-free survival and disease-free survival. Correlative objectives include the association of i) tumor infiltrating lymphocyte (TILs) levels in the primary tumor and RD with iDFS, ii) TILs with tucatinib benefit, iii) iDFS and circulating tumor cells (CTC) at serial timepoints and iv) the magnitude of benefit of tucatinib (iDFS) in patients with/without detectable pretreatment CTCs. Quality of life and pharmacokinetic endpoints are also being evaluated. Statistics: A011801 is a prospective, double-blind, randomized, phase III superiority trial; stratified by i) receipt of postoperative CT (Y/N), ii) hormone receptor-status (+/-), and iii) pathologic lymph node status (+/-). The study targets an absolute difference of 5% in iDFS (control vs. experimental arm 82% & 87%, HR = 0.7), with a two-sided alpha of 0.05 and power of 80%. The sample size is 981; target accrual = 1031 patients; activation and estimated completion dates are 01/6/21 and ~ 01/2028. Accrual as of 7/10/2023: 438 patients. Support: U10CA180821, U10CA180882; Seagen Inc; https://acknowledgments.alliancefound.org. ClinicalTrials.gov Identifier: NCT04457596 Citation Format: Ciara O'Sullivan, Karla Ballman, Linda McCall, Tyler Zemla, Anna Weiss, Melissa Mitchell, Victoria Blinder, Nadine Tung, William Irvin, Myounghee Lee, Sailaja Kamaraju, Matthew Goetz, W. Fraser Symmans, Virginia Borges, Ian Krop, Ann Partridge, Lisa Carey. A011801 (CompassHER2 RD): Postneoadjuvant T-DM1 + tucatinib/placebo in patients with residual HER2-positive invasive 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 PO3-18-11.

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 &lt; 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.

Abstract Adolescent and young adults (AYAs) (15-39 years) have a heightened risk of developing a second primary malignancy due to extended periods of survivorship, higher incidence of germline cancer predisposing variants, and increased susceptibility to treatment-induced malignancies. Research on survivors of specific AYA cancer types, including breast cancer (BC) survivors, is limited. Among BC survivors, while much survivorship research focuses on risk of locoregional recurrence or contralateral BC, little is known about overall risk, and risk factors, of developing second non-breast primaries. This prospective cohort study examined women diagnosed with BC from 2006-2016 at age ≤40 years enrolled in the Young Women’s BC Study (YWS) (N=1297). Women were excluded from the analytic cohort if initially diagnosed with Stage IV breast cancer (N=64). To enable investigation of how BC treatments may impact second primary risk, women were also excluded if they reported another cancer before primary BC diagnosis (N=3). Patient characteristics, treatment information, and clinical events were collected via serial surveys. Tumor characteristics and detailed treatment data were obtained from medical record review. Five- and 10-year risk of second non-breast primary was estimated via the cumulative incidence function after applying the Fine-Gray competing risks model with time starting at primary BC diagnosis. Death, metastasis, or diagnosis with a second primary BC were considered as competing events. Univariate and multivariate Fine-Gray sub-distribution models were used to estimate sub-distribution hazard ratios (sHRs) and 95% confidence intervals (CI) for second non-breast primary cancer risk. Risk factors considered included age, race, body mass index, smoking, alcohol use, income, family history of cancer, germline pathogenic variant (PV) carrier status, tumor stage, grade, and ER status, primary surgery type, and receipt of radiation, chemotherapy, or endocrine therapy (yes/no). Multivariate models tested individual associations with additional adjustment for radiation therapy and PV carrier status, as both are consistently associated with second primary in the literature. Over a median follow-up of 10.1 years (inter-quartile range (IQR) =7.9-12.1 y), 47 patients (4%) developed a second non-breast primary cancer. Median age at second non-breast primary was 43 years (IQR=39-46), and median time between primary BC and second non-breast primary was 7.3 years (IQR=4.1-9.3). Second primary types included melanoma (n=10), thyroid (n=10), ovarian (n=4), sarcoma (n=4), uterine (n=3), rectal (n=3), bladder (n=2), cervical (n=2), head and neck (n=2), lung (n=2), lymphoma (n=2), pancreatic (n=2), and kidney (n=1). During the study, 22 patients (2%) developed a second primary BC, 167 (19%) developed metastasis, and 15 (1%) died from causes other than BC. Among the patients who developed a second primary BC, two later developed another non-breast cancer (ovarian and brain cancer). When incorporating competing risks, five and 10-year cumulative incidence of second non-breast primary was 1.4% and 3.2%, respectively. No patient or treatment factors were statistically significantly associated with second non-breast primary in univariate or multivariate models, including radiation and PV carrier status. In this population of young BC survivors, 10-year cumulative incidence of second non-breast primary cancer was 3.2%, with the most common second cancers being melanoma and thyroid cancer. Incidence rates of all second primary cancer types in this cohort were higher than population-based incidence rates for healthy women under 50 years of age, highlighting the importance of long-term surveillance for other cancer events in this young population. While risk of second non-breast primary was not associated with primary BC treatment in this study, cases were limited, and the follow-up interval was relatively short. Citation Format: Bessie Zhang, Kristen Brantley, Shoshana Rosenberg, Gregory Kirkner, Laura Collins, Kathryn Ruddy, Rulla Tamimi, Lidia Schapira, Virginia Borges, Ellen Warner, Steven Come, Eric Winer, Ann Partridge. Second primary non-breast cancers in young breast cancer survivors [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 PO3-11-10.

Abstract Background: Young BC survivors are at risk for impaired QOL in part due to issues that are unique to their life stage. We sought to characterize trajectories of QOL in the 5 years following diagnosis among young BC survivors as well as evaluate patient and clinical characteristics associated with poorer or deteriorating QOL trajectories over time. Methods: Women diagnosed with stage I-III BC at age ≤40 enrolled in the Young Women’s BC Study, a prospective cohort in North America, who completed ≥2 study surveys through 5 years of post-diagnosis follow-up. QOL was evaluated with the Cancer Rehabilitation Evaluation System (CARES) physical, psychosocial, and sexual subscale scores. Demographic, treatment, and clinical characteristics were ascertained through surveys and chart review. Longitudinal trajectories for each CARES subscale were defined using group-based trajectory modeling; associations between patient/clinical characteristics and trajectory group membership were estimated for each subscale using multivariable multinomial logistic regression. Results: Among 900 women, median age at diagnosis was 36 (range: 17-40) 89% were white, 2% Black, and 4% Hispanic. At baseline, 73% were partnered, 61% parous and 49% perceived themselves as financially comfortable. Most had hormone-receptor positive (74%), HER2-negative (70%) BC, and most received chemotherapy (82%); 36% underwent mastectomy with radiation. Physical and psychosocial scores each clustered into 4 trajectories, with &gt;75% of participants clustering in groups reflecting excellent or good QOL that was stable over time and few (6% for physical and 4% for psychosocial) clustering into groups that reflected poorer QOL at baseline that did not improve over time. Sexual health trajectories were more variable, clustering into 5 trajectories, with over half of participants clustered into groups reflecting good (35%) or excellent (20%) QOL that remained relatively stable over time, 22% clustered into a trajectory that was poor at baseline but moderately improved over follow-up, 13% in a group that reflected deteriorating from moderate-to-poor QOL and 11% in a group with poor QOL at baseline that did not improve over time. In multivariable regression analyses (Table), factors associated with clustering in a poorer trajectory (vs. clustering in an excellent trajectory), in multiple QOL domains included baseline financial discomfort (associated with poorer QOL across all 3 domains), mastectomy+radiation (vs. lumpectomy, associated with poorer QOL across all 3 domains); chemotherapy receipt (associated with poorer physical and sexual health trajectories); and baseline BMI &gt;25 (vs. 18.5-24.9, associated with poorer physical and poorer/deteriorating sexual health trajectories). Conclusions: Young BC survivors follow distinct QOL trajectories in survivorship. While most will not experience substantial QOL impairment through the first 5 years following diagnosis, a substantial minority report persistently poor or deteriorating QOL. The association between more extensive local therapy and poorer physical/psychosocial/sexual health trajectories underscores the importance of communicating the potential for negative QOL outcomes when women are making surgical decisions. Additionally, the pervasive impact of financial wellbeing on multiple QOL domains supports the potential value of systematic screening for and addressing of financial distress to prevent or mitigate financial toxicity in survivorship Factors associated with clustering in poorer/deteriorating (vs. excellent) QOL trajectories *Reference trajectory=excellent QOL Citation Format: Tal Sella, Zheng Yue, Kathryn Ruddy, Shari Gelber, Rulla Tamimi, Jeffrey Peppercorn, Lidia Schapira, Virginia Borges, Steven Come, Eric Winer, Ann Partridge, Shoshana Rosenberg. Five-year quality of life (QOL) trajectories among young breast cancer (BC) survivors [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 PO2-12-01.

Abstract Background: Oncofertility counseling in BRCA carriers has unique challenges due to a possible negative impact of germline pathogenic/likely pathogenic variants (PVs) on reproductive potential and the indication to undergo risk-reducing bilateral salpingo-oophorectomy. While previous studies demonstrated the safety of pregnancy in women with prior breast cancer (BC) history, limited evidence exists in BRCA carriers specifically. We report the results of the largest study to date investigating likelihood of pregnancy after BC, reproductive and disease outcomes specifically in BRCA carriers. Methods: This was an international, multicenter, hospital-based, retrospective cohort study including young BRCA carriers with history of BC (NCT03673306). Eligible patients were women harboring germline PVs in BRCA1 and/or BRCA2 and diagnosed with stage I-III invasive BC at the age of ≤ 40 years between January 2000 and December 2020. BRCA healthy carriers or patients with BRCA variants of unknown significance, non-invasive BC, lack of follow-up, prior ovarian cancer or other malignancies without history of BC were excluded. Primary endpoints were pregnancy rate and disease-free survival (DFS). Overall survival (OS), BC specific survival (BCSS), pregnancy, fetal and obstetric outcomes were secondary endpoints. To mitigate the impact of guaranteed time bias, two survival analyses were performed: 1) Extended Cox model with occurrence of pregnancy as a time-varying covariate; 2) Case-control analysis by matching 1:3 patients with and without a pregnancy for type of BRCA PV, hormone receptor status, nodal status and year at diagnosis; moreover, each control had to have a disease-free interval longer than the time occurring between BC diagnosis and conception of the matched case. Results: From 78 centers worldwide, 4,732 patients were included, of whom 659 had at least one pregnancy after BC (pregnancy cohort) and 4,073 did not (non-pregnancy cohort). Patients in the pregnancy cohort were significantly more likely to carry BRCA1 PVs, to be younger at BC diagnosis, to have node-negative and hormone receptor-negative (HR-) BC (all p&lt; 0.01). Pregnancy rate at 10 years was 22% (95% CI 21%-24%) overall, 18% (95% CI 16%-21%) and 26% (95% CI 24%-26%) in patients with HR+ and HR- BC, respectively (p&lt; 0.01). Median time from BC diagnosis to conception was 3.5 years (IQR 2.2-5.3 years), significantly longer in patients with HR+ than HR- BC (4.3 vs 3.2 years, p&lt; 0.01). Among 659 patients with a pregnancy after BC, 45 (6.8%) and 63 (9.6%) experienced an induced abortion or a miscarriage, respectively. Of the 517 (78.5%) patients with completed pregnancy, 54 (10.4%) had twins and 406 (78.5%) delivered at term (delivery ≥37 weeks). Among the 571 babies born, 5 (0.9%) had congenital anomalies. Median follow-up was 7.8 years (IQR, 4.5-12.6 years). No significant difference in DFS was observed between the pregnancy and non-pregnancy cohorts (unadjusted HR 0.97, 95% CI 0.82-1.15, p=0.74; adjusted HR [aHR] 0.99, 95% CI 0.81-1.20, p=0.90). Patients in the pregnancy cohort showed significantly better BCSS (HR 0.53, 95% CI 0.38-0.74, p&lt; 0.01; aHR 0.59, 95% CI 0.41-0.86, p&lt; 0.01) and OS (HR 0.52, 95% CI 0.38-0.72, p&lt; 0.01; aHR 0.58, 95% CI 0.40-0.85, p&lt; 0.01). Similar results were obtained in the case-control analysis. Subgroup analyses of survival endpoints according to patient, tumor and treatment characteristics will be presented at the conference. Conclusions: In this global study, 1 out of 5 young BRCA carriers conceived within 10 years after a BC diagnosis, higher than rates previously reported in unselected young BC populations. Pregnancy following BC in BRCA carriers did not appear to adversely impact maternal prognosis or fetal outcomes. These findings should be incorporated into oncofertility counseling of young BRCA carriers with BC. Citation Format: Matteo Lambertini, Eva Blondeaux, Elisa Agostinetto, Anne-Sophie Hamy-Petit, Hee Jeong Kim, Camila Chiodi, Rinat Bernstein-Molho, Florentine Hilbers, Katarzyna Pogoda, Estela Carrasco Lopez, Kevin Punie, Jyoti Bajpai, Michail Ignatiadis, Halle Moore, Kelly-Anne Phillips, Angela Toss, Christine Rousset-Jablonski, Fedro Alessandro Peccatori, Tiphaine Renaud, Alberta Ferrari, Shani Paluch-Shimon, Robert Fruscio, Wanda Cui, Stephanie Wong, Claudio Vernieri, Kathryn Ruddy, Maria Vittoria Dieci, Alexios Matikas, Mariya Rozenblit, Cynthia Villareal Garza, Laura De Marchis, Lucia Del Mastro, Fabio Puglisi, Maria Del Pilar Estevez-Diz, Kenny A. Rodriguez-Wallberg, Bela Mrinakova, Sarah Meister, Luca Livraghi, Florian Clatot, Rinat Yerushalmi, Carmine De Angelis, Rodrigo Sánchez-Bayona, Icro Meattini, Natalia Cichowska-Cwalińska, Martine Berlière, Mahmoud Salama, Ugo De Giorgi, Amir Sonnenblick, Hatem Azim, Ann Partridge. Pregnancy after breast cancer in young women with germline BRCA pathogenic variants: results from an international cohort study [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 GS02-13.

Abstract Background: The POSITIVE trial recently demonstrated that temporary interruption of ET to attempt pregnancy does not increase the short-term risk of recurrence in pts with hormone receptor-positive (HR+) BC. Yet, uncertainty exists regarding the safety of ovarian stimulation for embryo/oocyte cryopreservation to preserve fertility in these pts. In addition, very limited data exist regarding safety and efficiency of ART to achieve pregnancy after ET interruption. Methods: POSITIVE is an international, single-arm, prospective trial that enrolled pts ≤ 42 years with stage I-III HR+ BC who had already received 18-30 months of ET prior to enrollment. The use of ART was a predefined 2ry endpoint. We evaluated factors associated with time to pregnancy in a Fine and Gray competing risks model, which included chemotherapy (chemo) ± GnRH analogue (GnRHa), age, prior ET, prior birth, and menstrual status at enrollment. The cumulative incidence of pregnancy at 12 months from enrollment by age was estimated controlling for competing risks. We performed a logistic regression model to evaluate whether ART use was associated with achieving pregnancy, adjusting for age, receipt of chemo ± GnRHa. The cumulative incidence of BCFI events was estimated according to whether or not ovarian stimulation for cryopreservation was performed at diagnosis and prior to enrollment. BC-free interval (BCFI) was defined as the time from enrollment until the first BC event (invasive local, regional, or distant recurrence or contralateral disease). A 24-month landmark analysis was performed to investigate the safety of ART use after enrollment. Median follow-up was 41 months. Results: 497 out of 516 included pts (96%) were followed for at least 6 months and were evaluable for pregnancy status. 368 out of 497 evaluable pts (74%) reported at least one pregnancy. In a multivariable model, young age was the only factor associated with shorter time to pregnancy. The cumulative incidence of pregnancy at 12 months was 64%, 54% and 38% for pts aged &lt; 35, 35-39 and 40-42 years, respectively. 179 pts (36.0%) had undergone ovarian stimulation for embryo/oocyte cryopreservation at diagnosis and prior to enrollment, of whom 68 (37.9%) reported cryopreserved embryo transfer after enrollment. 215 pts (43.3%) reported using any ART after enrollment, of whom 80 (37.2%) underwent ovarian stimulation for in-vitro fertilization (FIVET) or intracytoplasmic sperm injection (ICSI). Other ART used included clomiphene (n=19), intrauterine insemination (n=37) and egg donation (n=17). Pregnancy rates were 82.4% and 67.5% for women who underwent cryopreserved embryo transfer and FIVET/ICSI, respectively. In a multivariate model, cryopreserved embryo transfer was the only ART independently associated with a higher chance of pregnancy (OR:2.41, 95% CI: 1.75-4.95). The cumulative incidence of BCFI events at 3 years was similar for women who underwent ovarian stimulation for cryopreservation at diagnosis and before enrollment, 9.7% (95% CI: 6.0-15.4%), and those who did not, 8.7% (95% CI: 6.0-12.5%). A 24-month landmark analysis showed no impact of ovarian stimulation for FIVET/ICSI after enrollment on BCFI. Conclusions: This is the largest prospective study to investigate fertility preservation and ART in pts with HR+ BC. Young age was the main factor associated with shorter time to pregnancy. Embryo/oocyte cryopreservation at BC diagnosis followed by embryo transfer after ET interruption was the only approach associated with an increased chance of pregnancy. Ovarian stimulation either at BC diagnosis for embryo/oocyte cryopreservation or after enrollment to POSITIVE for FIVET/ICSI did not appear to impact prognosis in the short term. These data are of paramount importance for oncofertility counselling of young BC pts. Citation Format: Hatem Azim, Samuel Niman, Ann Partridge, Isabelle Demeestere, Monica Ruggeri, Marco Colleoni, Cristina Saura, Chikako Shimizu, Anna Saetersdal, Judith Kroep, Audrey Mailliez, Ellen Warner, Virginia Borges, Frédéric Amant, Andrea Gombos, Akemi Kataoka, Christine Rousset-Jablonski, Simona Borstnar, Junko Takei, Jeong Eon Lee, Janice Walshe, Manuel Ruíz - Borrego, Halle Moore, Christobel Saunders, Vesna Bjelic-Radisic, Snezana Susnjar, Fatima Cardoso, Natalie Klar, Tanya Spanic, Kathryn Ruddy, Martine Piccart, Larissa Korde, Aron Goldhirsch, Richard Gelber, Olivia Pagani, Fedro Alessandro Peccatori. Fertility preservation and assisted reproductive technologies (ART) in breast cancer (BC) patients (pts) interrupting endocrine therapy (ET) to attempt pregnancy [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 GS02-11.

Importance Observational studies of survivors of breast cancer and prospective trials of aspirin for cardiovascular disease suggest improved breast cancer survival among aspirin users, but prospective studies of aspirin to prevent breast cancer recurrence are lacking. Objective To determine whether aspirin decreases the risk of invasive cancer events among survivors of breast cancer. Design, Setting, and Participants A011502, a phase 3, randomized, placebo-controlled, double-blind trial conducted in the United States and Canada with 3020 participants who had high-risk nonmetastatic breast cancer, enrolled participants from 534 sites from January 6, 2017, through December 4, 2020, with follow-up to March 4, 2023. Interventions Participants were randomized (stratified for hormone receptor status [positive vs negative], body mass index [≤30 vs &amp;gt;30], stage II vs III, and time since diagnosis [&amp;lt;18 vs ≥18 months]) to receive 300 mg of aspirin (n = 1510) or placebo once daily (n = 1510) for 5 years. Main Outcomes and Measures The primary outcome was invasive disease–free survival. Overall survival was a key secondary outcome. Results A total of 3020 participants were randomized when the data and safety monitoring committee recommended suspending the study at the first interim analysis because the hazard ratio had crossed the prespecified futility bound. By median follow-up of 33.8 months (range, 0.1-72.6 months), 253 invasive disease–free survival events were observed (141 in the aspirin group and 112 in the placebo group), yielding a hazard ratio of 1.27 (95% CI, 0.99-1.63; P = .06). All invasive disease–free survival events, including death, invasive progression (both distant and locoregional), and new primary events, were numerically higher in the aspirin group, although the differences were not statistically significant. There was no difference in overall survival (hazard ratio, 1.19; 95% CI, 0.82-1.72). Rates of grades 3 and 4 adverse events were similar in both groups. Conclusion and Relevance Among participants with high-risk nonmetastatic breast cancer, daily aspirin therapy did not improve risk of breast cancer recurrence or survival in early follow-up. Despite its promise and wide availability, aspirin should not be recommended as an adjuvant breast cancer treatment. Trial Registration ClinicalTrials.gov Identifier: NCT02927249

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.