Citations

Abstract Background: We have identified two potentially predictive signatures of palbociclib resistance: the RBsig, composed of E2F1/E2F2 dependent genes, which is associated with genetic loss of RB1, and the ratio between the gene expression levels of CCNE1 to RB1 (CCNE1/RB1). Both signatures have been previously analyzed in vitro and in neoadjuvant and metastatic studies with palbociclib. The present analysis aims to explore the role of RBsig and CCNE1/RB1 in the phase III adjuvant PALLAS trial, which randomized patients to palbociclib plus endocrine therapy, versus endocrine therapy alone. Materials and methods: Gene expression data from PALLAS were generated using the HTG EdgeSeq Oncology BM Panel. Of the 87 genes composing RBsig, 46 were available within the EdgeSeq dataset and were used for the analyses; CCNE1 and RB1 were both available. RBsig was calculated as the mean of the Z-score scaled gene expression (log) of the 46 genes; CCNE1/RB1 was computed as the log ratio between the mRNA expression of CCNE1 and RB1. The prognostic/predictive effect of the continuous signatures in terms of invasive disease-free survival (IDFS), distant recurrence-free survival (DRFS), and overall survival (OS) was evaluated using Cox proportional hazard models. Results: HTG data were available from 2,587 of 5,748 patients from the entire PALLAS intention-to-treat (ITT) cohort. As RBsig and CCNE1/RB1 levels are affected by pre-surgical treatments, we limited the analyses to 1612 pre-treatment samples (530 core biopsies and 1082 surgical specimens) (analysis population). Compared with the entire PALLAS ITT cohort, the analysis population was significantly enriched for patients with low clinical risk (41.3% vs 59.4%) who did not receive prior chemotherapy (17.5% vs 55.9%). In keeping with the PALLAS ITT cohort, no significant benefit from the addition of palbociclib was observed in the analysis population. Higher baseline RBsig or CCNE/RB1 values were significantly and independently associated with worse IDFS (hazard ratio [HR] 1.63, 95% confidence interval [CI] 1.3-2.0; HR 1.22, 95%CI 1.1-1.3, respectively), DRFS (HR 1.94, 95%CI 1.5-2.5; HR 1.26, 95%CI 1.1-1.4, respectively) and OS (HR 1.79, 95% CI 1.3-2.4; HR 1.26, 95%CI 1.1-1.4, respectively) in the analysis population. No predictive effect of palbociclib benefit was observed for either signature in the analysis population, nor according to clinical risk or chemotherapy receipt. Interestingly, higher RBsig was strongly prognostic in patients who did not receive adjuvant chemotherapy (HR 1.83, 95%CI 1.4-2.3) but not in those who received it (HR 1.01, 95%CI 0.6-1.6) (interaction p=0.02) suggesting a potential predictive role of RBsig for chemotherapy benefit. Conclusions: In the PALLAS trial, higher baseline RBsig or CCNE1/RB1 values are associated with worse prognosis, but are not predictive of benefit from palbociclib in the adjuvant setting. RBsig might be associated with differential benefit from chemotherapy. Further study of these biomarkers may strengthen their role in risk stratification.https://acknowledgments.alliancefound.org Citation Format: L. Malorni, D. Hlauschek, E. Mayer, M. Benelli, L. Biganzoli, I. Migliaccio, A. Kermanidis, G. Pfeiler, E. P. Mamounas, A. M. Brufsky, M. Bellet-Ezquerra, K. Clifton, G. Rubovszky, T. Foukakis, M. Goetz, S. Lee, M. Ruiz-Borrego, W. Symmans, K. V. Ballman, F. Liu, J. Machacek-Link, C. Denkert, A. DeMichele, M. Gnant. Prognostic and predictive role of RBsig and CCNE1/RB1 gene-expression signatures for patients with early breast cancer treated with endocrine therapy with or without palbociclib in the PALLAS trial (ABCSG-42, AFT-05, BIG 14-03) [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr PS2-07-13.

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: 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.

Abstract Background: Pregnancy after breast cancer (BC) is of substantial importance for many young women at diagnosis and during follow-up. BC treatment including standard endocrine therapy (ET) (5-10 years) may reduce ovarian reserve and the chances of subsequent successful pregnancy, given conception is contraindicated during ET. A temporary interruption of ET to attempt and carry a pregnancy in this population has never been prospectively studied. Methods: POSITIVE is a single-arm, prospective, investigator-initiated, international trial evaluating the safety and pregnancy outcomes of interrupting ET for young women with early-stage hormone-receptor-positive (HR+) BC who desire pregnancy. The primary objective is to assess the risk of BC relapse associated with ET interruption for ~2 years to achieve pregnancy. Women ≤42 years with stage I-III HR+ BC who received adjuvant ET (SERM alone, GnRH analogue plus SERM or AI) for 18 to 30 months and wished to interrupt ET to attempt pregnancy were eligible. The primary endpoint is breast cancer free interval (BCFI) defined as the time from enrollment to the first BC event (local, regional, distant recurrence or a new invasive contralateral BC). Planned sample size was 500 patients. Three interim analyses of BCFI were reviewed by the Data Safety Monitoring Committee (DSMC) to assure a 95% chance of stopping the trial early if the annual BCFI event rate exceeded 4%; with primary analysis triggered after 1600 patient years of follow-up (pyfu) and no more than 46 BCFI events defined as the safety threshold. The DSMC recommended continuing the study following each interim analysis. We now report the primary results. Results: From 12/2014 to 12/2019, 518 women were enrolled. At enrollment, the median age of participants was 37 years (27-43 years); 75.0% were nulliparous, 93.4% had stage I/II disease, 66.3% node-negative. Median time from BC diagnosis to enrollment was 29 months (IQR: 25-32). Tamoxifen alone was the most prescribed ET (41.7%), followed by tamoxifen+ovarian function suppression (35.7%). 62.0% of participants had received neo/adjuvant chemotherapy. At a median follow-up of 41 months (1638 pyfu), 44 participants had experienced a BCFI event, not exceeding the pre-specified safety threshold of 46 events. The 3-year BCFI failure percent was 8.9% (95% CI: 6.3 to 11.6%), similar to the 9.2% (95% CI: 7.6 to 10.8%) calculated in the comparative external control cohort from the SOFT/TEXT trials (Sun et al, Breast 2020). Of 497 women followed for pregnancy status, 368 (74.0%) had at least one pregnancy, 317 (63.8%) had at least one live birth, with a total of 365 babies born. Based on competing risk analysis, 76.3% of patients resumed ET (half within 26 months), 8.3% had BCFI event/death before ET resumption, and 15.4% had not resumed ET yet. Conclusions: The POSITIVE trial demonstrates that for young women with early HR+ BC desiring pregnancy, temporary interruption of ET to attempt pregnancy does not confer a greater short-term risk of recurrence than that observed in a modern historical control group that did not interrupt ET. Most participants have had a live birth. Further follow-up is planned to confirm long-term safety. These results should be considered in counselling BC patients desiring future pregnancy. Citation Format: Ann Partridge, Olivia Pagani, Samuel M. Niman, Monica Ruggeri, Fedro Alessandro A. Peccatori, Hatem A. Azim, Marco Colleoni, Cristina Saura, Chikako Shimizu, Anna Saetersdal, Judith Kroep, Audrey Mailliez, Ellen Warner, Virginia F. Borges, Frédéric Amant, Andrea Gombos, Akemi Kataoka, Christine Rousset-Jablonski, Simona Borstnar, Junko Takei, Jeong Eon Lee, Janice Walshe, Manuel Ruiz Borrego, Halle Moore, Christobel Saunders, Vesna Bjelic-Radisic, Snezana Susnjar, Fatima Cardoso, Karen L. Smith, Teresa Ferreiro Vilarino, Karin Ribi, Kathryn Ruddy, Sarra El-Abed, Martine Piccart, Larissa A. Korde, Aron Goldhirsch, Richard D. Gelber. Pregnancy Outcome and Safety of Interrupting Therapy for women with endocrine responsIVE breast cancer: Primary Results from the POSITIVE Trial (IBCSG 48-14/BIG 8-13) [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr GS4-09.

Abstract Background: We previouslyreported that invasive disease-free survival (IDFS), the primary outcome, and distantdisease-free survival (DDFS), a secondary outcome, differed by menopausalstatus in a pre-specified analysis. Here,we report updates on IDFS and DDFS with additional follow-up, as well as distantrecurrence-free interval (DRFI) and post hoc analyses in premenopausal women.Methods: Eligibilitycriteria included women &gt; 18 years of age with HR+, HER2-BC and 1-3 +LN and no contraindications to taxane and/or anthracycline basedCT. DRFI was defined as time to distant recurrence or death from breast cancer.Analyses were intent-to-treat among eligible pts. We performed a post hocanalysis evaluating IDFS between treatment arms in premenopausal pts with pN1mi.In addition, we conducted a two-year landmarked IDFS analysis by ovarianfunction suppression (OFS) or not in the ET arm, as well as by regularmenstrual periods or not in both treatment arms.Results: Among the 4,984eligible pts, there were 553 IDFS events and median follow-up of 6.1 years.Postmenopausal women do not have any IDFS or DDFS benefit with CT; however, 5-yearabsolute benefits for IDFS and DDFS with CT for premenopausal pts were 5.9% and3.3%, respectively. In pre-menopausal pts, CT was associated with improved DRFIfor all RS values &lt; 25, with an absolute improvement of 2.3% for RS0-13 and of 2.8% for RS 14-25. Among premenopausal pts, 12.4% (n=206) had pNmi)disease. In a post hoc analysis, there was a trend for CT benefit for thosewith pNmi [hazard ratio (HR)=0.44, confidence interval (CI)=0.18-1.08]. Therewere only 22 IDFS events. Only 17.2% of premenopausal pts assigned to ETunderwent OFS in the first 24 months and in two-year landmarked analysis, therewas no IDFS difference in those who underwent OFS or not (HR=0.88,CI=0.47-1.63). In premenopausal women assigned to ET, 58.9% stopped havingperiods within the first 24 months, and have anumerically improved IDFS compared to those who continued regular periods (HR=1.48,CI: 0.92-2.40). Among premenopausal assigned to CT followed by ET, 80.8%stopped having periods within the first 24 months and have a numericallyimproved IDFS compared to those who continue to have regular periods (HR=1.56, CI:0.85-2.86).Discussion: In accordancewith the differential IDFS and DDFS benefit based upon menopausal status inS1007, premenopausal pts with 1-3+LN and RS &lt; 25 had a statisticallysignificant improvement in DRFI with the addition of CT. A small proportion of S1007premenopausal participants underwent OFS. The role of OFS as it relates to CTbenefit cannot be determined from this study. A future randomized trial should address the clinical question if OFScan replace CT in premenopausal pts with HR+/HER2-, node-positive breast cancer.Funding: Supported by National Cancer Institute grants U10CA180888, U10CA180819,U10CA180820, U10CA180821, U10CA180868, U10CA180863, and in part by Susan G.Komen for the Cure® Research Program, The Hope Foundation for Cancer Research,Breast Cancer Research Foundation, and Genomic Health, Inc. Citation Format: Kevin M Kalinsky, William E Barlow, Julie R Gralow, Funda Meric-Bernstam, Kathy S Albain, Daniel F Hayes, Nancy U Lin, Edith A Perez, Lori A Goldstein, Stephen KL Chia, Sukhbinder Dhesy-Thind, Priya Rastogi, Emilio Alba, Suzette Delaloge, Miguel Martin, Catherine M Kelly, Manuel Ruiz-Borrego, Miguel Gil-Gil, Claudia H Arce-Salinas, Etienne GC Brain, Eun Sook Lee, Jean-Yves Pierga, Begoña Bermejo, Manuel Ramos-Vasquez, Kyung Hae Jung, Jean-Marc Ferrero, Anne Schott, Steven Shak, Priyanka Sharma, Danika Lew, Jieling Miao, Debasish Tripathy, Lajos Pusztai, Gabriel Hortobagyi. Updated results from a phase 3 randomized clinical trial in participants (pts) with 1-3 positive lymph nodes (LN), hormone receptor-positive (HR+) and HER2-negative (HER2-) breast cancer (BC) with recurrence score (RS) ≤ 25 randomized to endocrine therapy (ET) +/- chemotherapy (CT): SWOG S1007 (RxPONDER) [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr GS2-07.

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