Citations

Abstract Background: Previous studies have demonstrated poorer survival of Black women with breast cancer. We assessed whether race/ethnicity was associated with disease-free (DFS) and overall survival (OS) among women with breast cancer enrolled in clinical trials for early-stage breast cancer according to tumor subtype, age, and body mass index (BMI). Methods: 10,011 women enrolled in one of four adjuvant chemotherapy trials: CALGB 9741, CALGB 49907, CALGB 40101, or NCCTG N9831. 9918 participants had available DFS and/or OS data and were included in the analysis. Cox models were used to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between race/ethnicity and DFS and OS. We compared Non-Hispanic (NH) Black (n=871), Hispanic (n=436), and other race participants (n=283) to NH Whites (n=7889). We assessed associations within strata of age group (<50, 50-<65, or ≥65), tumor subtype (hormone receptor (HR)+/HER2-, HR-/HER2+, or HR-/HER2-), and BMI (<25, 25-<30, or ≥30). Results: In multivariable-adjusted models, NH Black patients under 50 years of age had worse DFS compared to NH White patients (HR: 1.34, 95% CI: 1.10-1.62) and worse OS (HR: 1.64, 95% CI: 1.30-2.07). The differences in DFS and OS persisted in patients ages 50 to <65, though there were no significant differences in DFS or OS between NH Black and NH White patients ages ≥65. Among Hispanic and NH White participants, younger age at diagnosis was associated with greater DFS compared with older age overall while this was not true for NH Black patients. Among patients with HR+/HER2- tumors, NH Black patients when compared to NH White patients had worse DFS (HR 1.33, 95% CI: 1.04-1.70) but there was not a significant difference in OS (HR 1.35, 95% CI: 1.00-1.83). DFS and OS for other tumor subtypes did not significantly differ by race. Among patients with BMI <25, NH Black patients had significantly worse DFS (HR: 1.70, 95% CI: 1.25-2.30) and OS (HR:1.76, 95% CI:1.20-2.58) compared to NH White patients. There was no difference in survival between different race/ethnicity groups among individuals with BMI ≥25. Conclusions: Our results identified subgroups that may contribute to the observed disparities in survival between NH Black and NH White women with early-stage breast cancer. The greatest disparities are among individuals <50 years of age, those with HR+/HER2-, and those with BMI <25. These differences exist even within clinical trial populations with similar initial therapy, suggesting that disparities may be influenced by inequities in survivorship care and long-term treatment, such as endocrine therapy adherence and persistence, and/or differences in tumor or host biology. Support: U10CA180821 and U10CA180882; ClinicalTrials.gov Identifiers: NCT00003088, NCT00005970, NCT00024102, NCT00041119; https://acknowledgments.alliancefound.org Citation Format: Marla Lipsyc-Sharf, Karla V. Ballman, Jordan D. Campbell, Hyman B. Muss, Edith A. Perez, Lawrence N. Shulman, Lisa A. Carey, Ann H. Partridge, Erica T. Warner. Role of age, BMI, and tumor subtype in racial/ethnic disparities in breast cancer survival: A pooled analysis of four Alliance adjuvant clinical trials [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 494.

10607 Background: Young women with breast cancer who carry germline genetic pathogenic variants predisposing to breast and other cancers, including BRCA1 or BRCA2, may face unique challenges when making fertility decisions. Limited data exist on differences in fertility preferences, concerns, and preservation strategies between carriers and non-carriers. Methods: Participants in the Young Women’s Breast Cancer Study, a prospective cohort of women diagnosed with breast cancer at ≤ 40 yrs, who completed a baseline survey with a modified Fertility Issues Survey were included in this analysis. Genetic variant status was determined by medical record review complemented by survey self-report. We excluded carriers whose test date was after baseline survey completion or unknown. Fisher exact and Wilcoxon signed-rank tests were used to compare categorical and continuous variables, respectively, between carriers and non-carriers. Results: Of 1052 eligible women, 118 (11%) tested positive for a pathogenic variant (59% BRCA1, 32% BRCA2, 4% TP53, and 5% other unique pathogenic mutations) and 934 (89%) tested negative or were not tested. Carriers’ median age was 36 yrs (range 23-40) vs 37 (range 17-40, p = 0.01) in non-carriers. Similar proportions (p = 0.67) of carriers (38%, [45/118]) and non-carriers (37%, [343/934]) desired more biologic children before diagnosis. Desire declined after diagnosis similarly in both groups (carriers, 25% [29/118] vs non-carriers, 26% [242/934], p = 0.46). Among these women (n = 271), concern about passing on cancer risk to offspring was common and, although numerically higher among carriers, this difference was not statistically significant (carriers, 55% [16/29] vs non-carriers, 40% [96/242], p = 0.12). In contrast, among those not interested in or unsure about future fertility (n = 738), concern about cancer risk heritability was infrequently reported as affecting fertility decisions (carriers, 11% [9/83] vs non-carriers, 9% [56/655], p = 0.54). The same proportions (p = 0.89) of carriers (36% [43/118]) and non-carriers (36% [339/934]) were somewhat or very concerned about becoming infertile after cancer treatment, and fertility preservation strategy utilization was similar between groups (carriers, 11% [13/118] vs non-carriers, 12% [111/934], p = 0.21). Conclusions: Young women with breast cancer who carry germline pathogenic variants are similarly concerned about future fertility and as likely to pursue fertility preservation as non-carriers. Concern about cancer risk heritability was common among both carriers and non-carriers desiring future fertility, suggesting a gap between perceived and actual risk. Genetic counseling should be included in fertility discussions for all young women with breast cancer, with tailored, risk-mitigating recommendations for those who carry genetic variants.

524 Background: OFS is an important treatment component for premenopausal women with early and advanced HR+ BC and optimal efficacy may depend on complete E2 suppression with GnRHa, especially when combined with aromatase inhibitors (AI). However, standard assays lack sensitivity and accuracy at very low E2 concentrations, rendering detection of breakthrough ovarian function challenging. More informative data regarding endocrine effects of GnRHa are needed, particularly in young women who derive the most benefit from OFS yet more frequently had breakthrough E2 levels in the SOFT trial substudy, SOFT-EST. Methods: Using a prospective cohort study of women with BC diagnosed at age ≤ 40 years, we identified participants with stage I-IV HR+ BC on OFS treatment with leuprolide, goserelin or triptorelin and blood collected 1 year after diagnosis. Clinical data were obtained through surveys and medical records. Plasma estrogens were measured by liquid chromatography-tandem mass spectrometry, with a limit of detection of 0.2 pg/mL compared to 10 pg/mL with standard assays. We assessed the proportion of women on OFS with E2 > 2.72 pg/mL (10 pmol/L) and > 10 pg/mL. Patient characteristics, estrone (E1) and FSH levels, and disease-free (DFS) and overall survival (OS) were compared between those with and without elevated E2 using Fischer’s exact, Wilcoxon rank sum and log rank tests, respectively. Results: Of 84 patients who met inclusion criteria, 72 (86%) had stage I-III and 12 (14%) had stage IV BC; 25 were on OFS plus AI and 59 were on OFS plus tamoxifen (TAM). Median E2 was 3.1 pg/mL (range 0.2-30.9). 46 patients (55%) had E2 > 2.72 pg/mL, including 8 on AI and 38 on TAM; 4 (5%) had E2 > 10 pg/mL, including 1 on AI and 3 on TAM. Factors associated with E2 > 2.72 pg/mL were no prior chemotherapy, TAM and high E1 ( P ≤.05), but not age, BMI or GnRHa schedule (Table). After a median follow-up of 7 years, DFS events were seen in 6 patients with E2 > 2.72 pg/mL and 5 without ( P =.232); OS events were seen in 7 patients with E2 > 2.72 pg/mL and 5 without ( P =.608). Conclusions: More than half of young women with ER+ BC had E2 > 2.72 pg/mL on OFS, 91% of whom would not have been detected by standard assays. This may be an area amenable to intervention to improve outcomes in young women. However, larger studies are needed to elucidate the optimal E2 target on OFS and clinical implications of incomplete E2 suppression on ultrasensitive assays. [Table: see text]

Abstract Background: Knowledge regarding risk of treatment-induced premature ovarian insufficiency (POI) is crucial for appropriate oncofertility counseling. While the gonadotoxicity of anthracycline- and cyclophosphamide-based chemotherapy (CT) in young breast cancer (BC) patients (pts) is well established, the impact of anti-HER2 agents remains largely unknown and limited conflicting evidence exists for taxanes. Anti-Mullerian hormone (AMH) is an established biomarker of ovarian reserve; its measurements during systemic therapies may aid in diagnosis and prediction of POI. The NeoALTTO trial represented a unique setting to explore the acute gonadotoxicity of anti-HER2 therapy alone and in combination with weekly paclitaxel in pts not previously exposed to any other potentially gonadotoxic anticancer treatment. Methods: NeoALTTO (NCT00553358) is a multicenter, open-label, randomized phase III neoadjuvant trial in HER2-positive early BC pts randomized to receive lapatinib (L), trastuzumab (T), or their combination (L+T) alone for 6 weeks followed by the addition of paclitaxel for 12 weeks before surgery.The present analysis included only premenopausal women aged ≤45 years with available frozen serum samples at baseline (i.e. before administering any anticancer treatment), at week 2 (i.e. “biological window” of anti-HER2 therapy alone) and/or at surgery (i.e. after completion of paclitaxel plus anti-HER2 therapy). Central AMH testing was performed at Erasme Hospital (Brussels, Belgium) with the Roche Elecsys® AMH Plus assay (LoD=0.010 ng/ml). AMH levels during anti-HER2 therapy alone and then combined with paclitaxel were assessed as a measure of treatment impact on ovarian reserve. The impact of different anti-HER2 agents (T and/or L), pts’ age and baseline AMH levels on treatment gonadotoxicity were also investigated. Results: The present analysis included 130 pts with a median age of 38 years (IQR: 33-42 years), of whom 86 (66.2%) were ≤40 years. At baseline, median AMH levels were 1.29 ng/mL (IQR 0.56 - 2.62 ng/mL). At week 2, a small but significant reduction in AMH levels was observed (median value: 1.10 ng/mL, IQR 0.45 - 2.09 ng/mL, p<0.001; median cumulative decrease: -12.5%, IQR -37.6% - 12.4%). At surgery, there was a large significant decline in AMH levels (median value: 0.01 ng/mL, IQR 0.01 - 0.03 ng/mL, p<0.001; median cumulative decrease: -99.9%, IQR -100.0% - -98.7%). Type of anti-HER2 treatment (L vs. L vs. T+L) did not impact the results: there was no significant difference between treatment arms in degree of reduction in AMH levels at week 2 (p=0.763) or at surgery (p=0.700). Age and pre-treatment ovarian reserve had a major impact on treatment-induced gonadotoxicity risk, with a more profound decrease in AMH levels observed for older pts (p<0.001) and those with lower baseline AMH levels (p<0.001). Among pts aged <35 years, there was no significant difference in AMH levels between those with (n=7) or without (n=35) a subsequent pregnancy at baseline (p=0.316), week 2 (p=0.463) or at surgery (p=0.610). Conclusions: This biomarker analysis of the NeoALTTO trial showed for the first time the potential acute gonadal damage induced by anti-HER2 therapies alone and with the addition of weekly paclitaxel. We observed a small but significant reduction in AMH levels during T and/or L alone and then a profound reduction to almost undetectable levels following the addition of weekly paclitaxel, without differences by specific anti-HER2 regimen. Age and pre-treatment AMH levels strongly impacted gonadotoxicity risk. While this analysis is limited by lack of AMH measurement in longer term follow-up, findings have important implications for future research and oncofertility counseling of premenopausal women with HER2-positive BC. Citation Format: Matteo Lambertini, Marcello Ceppi, Richard A. Anderson, David A. Cameron, Marco Bruzzone, Maria Alice Franzoi, Claudia Massarotti, Sarra El-Abed, Yingbo Wang, Christophe Lecocq, Paolo Nuciforo, Rebecca Rolyance, Lajos Pusztai, Joohyuk Sohn, Jacopo Ligato, Maria Maddalena Latocca, Luca Arecco, Barbara Pistilli, Kathryn J. Ruddy, Alberto Ballestrero, Lucia Del Mastro, Fedro A. Peccatori, Ann H. Partridge, Cristina Saura, Michael Untch, Martine Piccart, Serena Di Cosimo, Evandro de Azambuja, Isabelle Demeestere. Impact of anti-HER2 therapy alone and in association with weekly paclitaxel on the ovarian reserve of young women with HER2-positive early breast cancer: Biomarker analysis of the NeoALTTO trial [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 PD5-05.

Abstract Background: Neoadjuvant ET (NET) offers an opportunity to assess ET sensitivity for ER+ HER2- BC and potentially to tailor therapy. Ki67 >10% on biopsy after 2-4 weeks (wks) of NET identifies patients (pts) with intrinsic ET resistance; while pathologic complete response (pCR) and modified preoperative endocrine prognostic index of 0 (mPEPI 0: pT1-2N0, Ki67 ≤2.7%) at surgery indicates sensitivity to ET. However, on-NET biopsy is not always acceptable or feasible and delays the ET sensitivity determination. PAM50 ROR score and intrinsic subtypes by tumor RNA profiling are prognostic in pts with early stage ER+ HER2- BC, and predict pCR rates to neoadjuvant chemotherapy (NCT) (PMC2667820). We therefore hypothesized that PAM50 analysis on pre-NET biopsies could predict the likelihood of a) a high on-NET Ki67, b) mPEPI-0 or pCR at surgery and, c) pCR for pts triaged to NCT. Methods: The ALTERNATE trial is a phase III study that randomized postmenopausal pts with clinical stage II/III ER+ (Allred score 6-8) HER2- BC to receive neoadjuvant anastrozole, fulvestrant, or both for 6 months before surgery. Research biopsy was required at pre-NET and wk 4, then optional at wk 12. Pts with Ki67 >10% on biopsy at wk 4 or 12 discontinued NET and were offered NCT. PAM50 intrinsic subtype and ROR-P values were generated from mRNA sequencing (RNASeq) analysis on pre-NET biopsies using open-source informatics (PMC7723687) and evaluated for prediction of on-NET Ki67 >10% at wk 4 or 12, pCR or mPEPI-0 post NET, and pCR post NCT. Results: 749 of 1,297 eligible trial pts were included in the analyses, after excluding 548 pts due to insufficient pre-NET tumor for RNASeq (n=511) or PAM50 normal subtype (n=37). Similar to the entire ALTERNATE population, the rate of Ki67 >10% at wk 4 or 12 was 24.4% (95% CI: 21.4-27.7%) and the rate of mPEPI-0/pCR post NET was 19.8% (95% CI: 17.0-22.8%). There were 393 (52.5%) Lum A, 302 (40.3%) Lum B, and 54 (7.2%) non-Lum (9 Basal, 45 HER2-E) BCs. These included 196 (26.2%) ROR-P low, 354 (47.3%) ROR-P medium and 199 (26.6%) ROR-P high BCs. Both the rates of Ki67 >10% at wk 4 or 12 and mPEPI-0/pCR differed significantly with respect to PAM50 subtype or ROR-P category, such that Lum A or ROR-P low BCs were least likely to have a Ki67 >10% at wk 4 or 12 and most likely to achieve mPEPI-0/pCR (Table). 93 of 168 (55.4%) pts triaged to NCT had RNA-seq results, yielding 26 Lum A, 49 Lum B, 4 Basal and 14 HER2-E, with the pCR rates of 0%, 6.1%, 0%, and 21.4%, respectively. There were 10 ROR-P low, 39 medium, and 44 high tumors, with a pCR rate of 0%, 5.1% and 9.1%, respectively. Conclusion: These data indicate that both baseline ROR-P and intrinsic subtype are predictive of early on-NET Ki67 > 10% and mPEPI 0/pCR at surgery after NET. For pts triaged to NCT based on an early on-NET Ki67 >10%, the HER2-E group had the highest pCR rate (20%) and no pCRs were observed in Lum A. These data may be useful for directing neoadjuvant therapy in postmenopausal pts with ER+ HER2- BC. Support: U10CA180821, U10CA180882, U24CA196171, UG1CA189856, U10CA180868 (NRG), NCI BIQSFP, BCRF, Genentech, AstraZeneca. https://acknowledgments.alliancefound.org. (MJE) CPRIT RR140033, P50CA186784, P50-CA58223, U01 CA214125, U24CA210954, Gift from Ralph and Lisa Eads, McNair Scholarship. Trials.gov Identifier: NCT01953588. Table 1.Rates of Ki67 >10% and mPEPI-0/pCR post NET by PAM50 subtype and ROR-P categoryKi67 >10% at wk 4 or 12mPEPI 0/pCR post NETPAM50 SubtypenYes, n (%)PnNo, n (%)PLum A37251 (13.7%) 95% CI: 10.4-17.6%<0.0001393104 (26.5%) 95%CI: 22.2-31.1%<0.0001Lum B29394 (32.1%) 95% CI: 26.8-37.8%30243 (14.2%) 95%CI: 10.5-18.7%Non-luminal (Basal and HER2-E)5338 (71.7%) 95%CI: 57.6-83.2%541 (1.9%) 95%CI: 0.05-9.9%ROR-P CategorynYes, n (%)PnNo, n (%)PLow18018 (10.0%) 95%CI: 6.0-15.3%<0.000119660 (30.6%) 95%CI: 24.2-37.6%<0.0001Intermediate34474 (21.5%) 95%CI: 17.3-26.2%35471 (20.1%) 95%CI: 16.0-24.6%High19491 (46.9%) 95%CI: 39.7-54.2%19917 (8.5%) 95%CI: 5.1-13.3% Citation Format: Cynthia X Ma, Meenakshi Anurag, Travis Dockter, Jeremy Hoog, Aranzazu Fernandez-Martinez, Cheng Fan, Richard Gibbs, Souzan Sanati, Kiran Vij, Mark Watson, Olwen Hahn, Joseph Guenther, Abigail Caudle, Erika Crouch, Amy Tiersten, Monica Mita, Wajeeha Razaq, Tina J Hieken, Yang Wang, A. Marilyn Leitch, Gary W Unzeitig, Anna Weiss, Eric P Winer, Kelly Hunt, Ann H Partridge, Lisa A Carey, Charles M Perou, Matthew J Ellis, Vera Suman. Pam50 intrinsic subtype and risk of recurrence score (ROR) for the prediction of endocrine (ET) sensitivity and pathologic response to chemotherapy in postmenopausal women with clinical stage II/III estrogen receptor positive (ER+) and HER2 negative (HER2-) breast cancer (BC) in the alternate trial (Alliance A011106) [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 PD9-03.

Abstract Background: Extended adjuvant endocrine therapy (eET) beyond the first 5 years of ET improves long-term outcomes in breast cancer survivors. For women who remain premenopausal, evidence for benefit has only been demonstrated to date for 5 years of additional tamoxifen, after an initial 5 years of tamoxifen (from ATLAS, aTTom). There are no data available for eET among premenopausal women treated with initial adjuvant aromatase inhibition (AI) and ovarian functions suppression (OFS). Thus, there is uncertainty regarding the optimal eET regimen for young breast cancer survivors. Methods: The Young Women’s Breast Cancer Study (YWS) is a multicenter prospective cohort of women age ≤40 years newly diagnosed with breast cancer between 2006-2016. Women with stage I-III hormone receptor positive breast cancer, ≥6 years post-diagnosis without breast cancer recurrence were considered candidates for eET. Use of eET was elicited on surveys completed at 6, 7 and/or 8 years post-diagnosis, censoring for recurrence or death. Those completing ≥1 survey were eligible for analysis. Patient characteristics were compared by Chi-square test between eET users and non-users, and logistic regression applied to identify factors associated with eET use. Results: Of 667 potential eET candidates, 73.9% (493/667) returned ≥1 survey between year 6-8 and were eligible for analysis. Compared to those without a year 6-8 survey, the analytic cohort tended to be more non-Hispanic white (86.0% v. 77.6%), more financially comfortable (53.9% v. 39.5%) and more likely to have children pre-diagnosis (59.6% v. 41.4%); age and disease characteristics were similar. Overall, 59.6% (294/493) reported any eET use, with use declining over time from 56.9% (265/466) to 51.4% (219/426) to 46.8% (162/346) at years 6, 7 and 8 post-diagnosis, respectively. Among eET users (n=294), tamoxifen monotherapy was the most common approach (76.9%, 226/294), followed by AI monotherapy (22.1%, 65/294, presumably women who transitioned into menopause), AI-OFS (7.1%, 21/294) and tamoxifen-OFS (3.1%, 9/294). Women diagnosed after 2012 were as likely to receive eET as those diagnosed 2006-2011 (59.4%, 117/197 v. 59.8%, 177/296 p=0.928), however eET more often included AI, with or without OFS (41.0% v. 18.6%, p<0.001), or OFS (17.9% v. 7.3%, p=0.005) in later years. In multivariable analysis, increasing age (per year odds ratio [OR]: 1.10, 95% confidence interval [CI]: 1.04-1.15, p<0.001), higher stage (II v. I: OR: 2.85, 95% CI: 1.81-4.48, p<0.001; III v. I: OR: 3.73, 95% CI: 1.87-7.42, p<0.001) and receipt of chemotherapy (OR: 3.50, 95% CI: 2.08-5.91, p<0.001) were independently significantly associated with any eET use, while women not of white non-Hispanic race/ethnicity were less likely to report eET use (OR: 0.49, 95% CI: 0.28-0.87, p=0.014). Rates of pregnancy in years 1-5 did not differ between eET users and non-users (10.0%, 29/291 v. 8.7%, 17/195, p=0.645) Conclusion: The majority of eligible young breast cancer survivors in the YWS have received eET despite limited data regarding its utility in this population. Heterogeneity exists regarding strategies utilized, and while some factors associated with eET use appear to reflect appropriate risk-based care, such as stage and receipt of chemotherapy, others, including age and race, suggest disparate uptake. Clinical studies are needed in order to determine the optimal approach to eET for young women with a history of early stage hormone receptor-positive breast cancer who remain premenopausal following 5 years of ET. Ensuring risk and preference-based uptake of eET should be a priority. Citation Format: Tal Sella, Yue Zheng, Shoshana M Rosenberg, Kathryn J Ruddy, Shari I Gelber, Rulla M Tamimi, Jeffrey M Peppercorn, Lidia Schapira, Virgina F Borges, Steven E Come, Lisa A Carey, Eric P Winer, Ann H Partridge. Extended adjuvant endocrine therapy in a longitudinal cohort of young breast cancer survivors [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 PD13-10.

Abstract Background: As the development and use of oral anticancer agents increases, it is critical to understand patient adherence to both standard and investigational agents. The open label, phase 3 multicenter PALLAS trial investigates whether adding 2 years of the CDK4/6 inhibitor palbociclib (P) to adjuvant endocrine therapy (ET) improves invasive disease-free survival (iDFS) over adjuvant ET alone in patients (pts) with HR- positive, HR2-negative, stage II-III breast cancer. Pts were randomly assigned to either Palbociclib (125 mg/day, 3 weeks on, 1 week off, in a 28-day cycle) plus ongoing provider/patient-choice adjuvant ET (P+ET) versus ET alone. We examined patient-reported adherence to ET +/- P during the first two years of study treatment. Methods: Adherence outcomes were measured in English-speaking pts in the U.S., UK, Ireland and Australia, Spanish-speaking pts in Spain and Mexico, and German-speaking pts in Germany and Austria. Adherence measures included drug diaries completed at each cycle, pill counts (for P only) collected at each study visit, and the Morisky Medication Adherence Scale-4 item and the McHorney Adherence Estimator questionnaires completed at cycles 2, 3, 6, 12, 18, and 24 (22 months). Mean adherence for each cycle was defined as the average proportion of prescribed pills taken (via drug diary) across all patients who initiated that cycle. Persistence was defined as the duration of drug initiation to treatment cessation (via drug diary). Generalized estimating equations were used to model the “most adherent” pts on the Morisky (score = 5 vs score <5) and “low risk” for adherence problems on the McHorney (score=0 vs score >0) to compare the average difference between arms over time for ET, adjusting for baseline demographic and clinical variables. Results: 81% (N=4688) of PALLAS pts were included in this analysis. Median persistence to ET was 23.6 months in P + ET (n=2169), 23.7 months in ET alone (2136) and 20.4 months for P (n=2194). The number of pts who initiated each cycle for ET declined over time and was similar between arms; the decline was more marked for P (Table 1). Mean adherence range as measured by drug diary was 98.2-99.3% for ET in P+ET and 98.0 - 99.4% in ET alone; and for P, ranged from 93.4 - 98.8%. The adherence and persistence results were nearly identical whether measured by drug diary or pill count for P. The observed percent “most adherent” for P measured by the Morisky scale ranged from 71.9% - 79.6% and the percent “low risk” for adherence problems measured by the McHorney scale, 64.0% - 73.4%. The percent of pts “most adherent” and “low risk” for adherence problems to ET was higher, on average over time, in the P+ET group compared to ET alone (75% vs 68%, p<0.01; 75% vs 72%, p=.05, respectively). Conclusions: Self-reported mean adherence for both P + ET and ET alone was strikingly high for pts who remained on therapy; persistence was also high with ET during the 2-year treatment period. Current analyses suggest that nonadherence to either P or ET was likely not a major contributor to the iDFS results seen in the overall PALLAS trial. These results illustrate the importance of measuring and monitoring patient adherence to oral study agents. Support: AFT, Pfizer; ClinicalTrials.gov (NCT02513394) and EudraCT (2014-005181-30). https://acknowledgments.alliancefound.org Table 1.Adherence and persistence in PALLAS over the 24 month treatment periodPalbocicilb + ETETPalbociclibETETTreatment cycleMean Adherence (SD)N*Mean Adherence (SD)NMean Adherence (SD)N193.4 (13.8)229098.7 (6.1)230999.0 (5.2)2343294.7 (13.3)218198.8 (6.4)220398.4 (7.1)2206397.4 (10.1)211298.7 (7.3)214298.8 (6.3)2168497.6 (10.2)203598.6 (7.8)211099.0 (5.7)2154597.6 (11.1)197598.3 (7.9)209398.1 (8.3)2148698.1 (8.7)189998.7 (6.6)203798.5 (8.2)2116798.1 (9.3)185599.0 (6.3)201298.6 (7.3)2102898.0 (9.1)181098.2 (8.2)199798.1 (8.2)2092998.4 (7.4)173399.0 (6.4)196298.8 (6.8)20511098.3 (8.6)171499.2 (4.9)194699.0 (5.5)20381198.3 (8.0)169198.5 (7.3)193798.2 (8.2)20311298.7 (6.2)161299.1 (5.3)191098.7 (7.5)19861398.5 (7.7)159698.9 (6.4)189398.8 (7.1)19691497.9 (9.3)157698.4 (7.3)188298.0 (9.1)19611598.5 (6.9)151499.2 (4.6)185499.0 (6.0)19281698.2 (8.7)148699.1 (4.6)183599.1 (5.7)19131798.1 (9.8)147998.3 (7.8)182698.5 (6.4)19031898.7 (6.8)141699.3 (4.1)176899.2 (5.3)18601998.7 (7.3)140899.3 (3.8)175699.4 (3.1)18482098.4 (8.9)139798.9 (5.3)174298.7 (5.8)18382198.5 (7.5)130199.0 (6.1)167698.8 (7.1)17842297.8 (9.7)124698.8 (6.2)164799.2 (5.7)17692398.1 (8.8)118098.2 (8.5)161998.4 (8.0)17552498.8 (7.2)108699.0 (6.3)146898.9 (7.1)16192598.8 (6.7)99699.2 (5.2)143298.8 (7.1)15892697.9 (11.2)84599.1 (5.7)140998.6 (8.8)1578ET=Endocrine therapy * Number of pts who initiated the treatment cycle. Citation Format: Eileen Shinn, David Zahrieh, Angela DeMichele, Nick Zdenkowski, Julie Lemieux, Jun Mao, Vesna Bjelic-Radisic, Michelle Naughton, Georg Pfeiler, Karen Gelmon, Ingrid Mayer, Daniel Egle, Gabriele Zoppoli, Tiffany Traina, Miguel Martin Jiménez, Silvia Antolin Novoa, Tufia Haddad, Arlene Chan, Alistair Edward Ring, Antonio Wolff, Jose JuanPonce Lorenzo, Dhanusha Sabanathan, Hal Burstein, Zbigniew Ireneusz Nowecki, Gunda Pristauz-Telsnigg, Adam Brufsky, Meritxell Bellet-Ezquerra, Theodoros Foukakis, Yelena Novik, Gabor Rubovszky, Karoline Muehlbacher, Otto Metzger, Theodora Goulioti, Ernest Law, Ann Partridge, Lisa Carey, Alex Zoroufy, Dominik Hlauschek, Christian Fesl, Erica Mayer, Michael Gnant. Adherence with adjuvant endocrine therapy with or without Palbociclib in the PALLAS trial [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 P4-12-01.

Abstract Background: Quality of life (QOL) in breast cancer patients (pts) can be greatly impacted by initial treatment and ongoing therapy, particularly if side effects and symptoms are not well tolerated. The PALLAS trial investigated whether the addition of 2 years of palbociclib (palbo) to adjuvant endocrine therapy (ET) improved invasive disease-free survival (iDFS) over adjuvant ET alone. We report on the main patient-reported outcome (PRO) quality of life (QOL) and symptom severity results of this trial by treatment arm. Methods: PALLAS is an ongoing multicenter, open label phase 3 trial that enrolled hormone receptor positive, HER2-negative, stage II-III breast cancer patients at 406 cancer centers across 21 countries. Patients were randomly assigned (1:1) to either 2 years of palbo (125mg/day, 3 weeks on 1 week off) plus ongoing provider or patient-choice adjuvant ET (palbo+ET) versus ongoing ET alone. The primary study endpoint was iDFS. Treatment with palbo in all pts stopped at the time of the second interim analysis (5/2020) due to futility; all pts then moved to follow up. The PRO analyses were triggered for completion after awareness of the pre-specified 469 iDFS cases in November 2020. Eight PRO endpoints were measured serially (i.e., day 1 of each monthly cycle for the first 3 months, then every 3 months for the first 2 years, and once at year 3). The endpoints were the EORTC QLQ-C30 global health status/QOL score, the Brief Fatigue Inventory score, the modified Brief Pain Inventory severity and pain interference scores, the EORTC QLQ-BR23 alopecia score, and the Breast Cancer Prevention Trial hot flash symptoms, vaginal problems, and musculoskeletal pain scores. Linear mixed models compared the average difference between arms across time points during the initial 2-year treatment period adjusting for cycle 1 day 1 (C1D1) PRO scores, demographic and clinical variables. The average differences between arms (palbo+ET vs ET alone) and the two-sided (1-[0.05/8]) x 100% confidence intervals, adjusted for multiple comparisons, were calculated. Analysis of covariance compared the average between-arm differences by endpoint at 3 years. Results: The PRO intention to collect population included 4688 (81%) of the overall trial pts, and was clinically and demographically representative of the remaining 1073 pts. Each analysis population, with measures at C1D1 and at least 1 post-C1D1 assessment for each PRO endpoint, comprised ≥ 89% of the 4688 pts and the proportions were similar between arms. After adjustment for baseline covariates, on average, no clinically important differences between arms were observed for any of the eight endpoints over the 2 year treatment period (Table 1). All effect sizes were below the pre-specified 0.2 threshold. These PRO results were similar at the 3 year time point. Conclusions: No clinically significant differences in either patient-reported QOL or symptom severity were found, on average, between participants in the two PALLAS treatment arms while either taking palbo+ET or ET alone, or after study-wide termination of palbo. In general, the addition of palbociclib in the adjuvant breast cancer setting did not contribute to increased symptom burden within this survivorship population. Further analyses will examine the relationship between PROs and treatment discontinuation by arm and study time point. Support: AFT, Pfizer, https://acknowledgments.alliancefound.org Table 1.Results of the Patient-Reported QOL and Symptom Severity Analyses Between the Two Treatment Arms During the First 2 Years of PALLASPRO Endpoint *Palbo + ET Adjusted average score (95% CI)ET alone Adjusted average score (95% CI)Average Difference + (Palbo + ET vs ET alone)[99.38% CI] Clinically ++ Important DifferenceEORTC QLQ-C30 Global Health Status/QOL71.7 (71.2, 72.2)74.0 (73.5, 74.5)-2.3 (-3.3, -1.4)**NoBrief Fatigue Inventory Score2.3 (2.2, 2.3)2.1 (2.0, 2.1)0.2 (0.1, 0.3)NoModified Brief Pain Inventory - Severity Score2.3 (2.2, 2.3)2.4 (2.4, 2.5)-0.2 (-0.3, -0.1)NoModified Brief Pain Inventory - Interference Score1.7 (1.6, 1.7)1.7 (1.6, 1.7)0.0 (-0.1, 0.1)NoEORTC QLQ-BR23 Alopecia1.4 (1.4, 1.4)1.3 (1.3, 1.3)0.1 (0.1, 0.1)NoBreast Cancer Prevention Trial - Hot Flash Symptoms1.2 (1.2, 1.3)1.2 (1.2, 1.3)0.0 (-0.1, 0.1)NoBreast Cancer Prevention Trial - Vaginal Problems0.8 (0.8, 0.8)0.8 (0.7, 0.8)0.0 (0.0, 0.1)NoBreast Cancer Prevention Trial - Musculoskeletal Pain1.2 (1.2, 1.2)1.3 (1.3, 1.3)-0.1 (-0.2, 0.0)No* For the EORTC QLQ-C30 Global Health Status/QOL subscale, higher scores indicate better QOL. For all other PRO endpoints, higher scores indicate worse symptom levels. ** The lower bound of the one-sided CI (adjusted for multiple comparisons) was -3.3. Because the lower limit is greater than the pre-specified non-inferiority margin of -3.44, non-inferiority of palbo+ET relative to ET-alone was concluded. The non-inferiority margin corresponds to a 0.2 SD in the EORTC QLQ-C30 global health/QOL score. +The average difference was adjusted for the following baseline covariates: Cycle 1 day 1 score, region (if applicable), age category, first adjuvant ET, race, ethnicity, N-stage, T-stage, histological grade, PgR, prior chemotherapy, ECOG Performance Status. ++Based on each instrument’s published clinically relevant cut-offs, if available. After calculating Cohen’s d treatment effect sizes, (i.e. by dividing the average difference by the ET-alone arm standard deviation from cycle 1 day 1), all effect sizes were below the pre-specified 0.2 threshold, and would not be considered clinically important. Citation Format: Michelle Joy Naughton, David Zahrieh, Michael Gnant, Nicholas Zdenkowski, Julie Lemieux, Jun J Mao, Vesna Bjelic-Radisic, Eileen Shinn, Marija Balic, Christoph Thomssen, Jane Neisel, Manuel Ruiz-Echarri, Sibylle Loibl, Claudine Isaacs, David Cameron, Fernando Manuel Henao Carrasco, Matthew Goetz, Viktor Wette, Gustavo Werutsky, Hope Rugo, Marcus Vetter, Ling-Ming Tseng, Kathy Miller, Florian Fitzal, Juan Miguel Gil Gil, Haeseong Park, Barbro Linderholm, Emilio Bajetta, Zoneddy Dayao, Aleix Prat, Karin Ehrhardt, Otto Metzger, Amal Arahmani, Ernest Law, Ann Partridge, Lisa Carey, Alex Zoroufy, Amylou Dueck, Dominik Hlauschek, Angela DeMichele, Erica Mayer. Quality of life and symptom severity in the PALLAS randomized trial of palbociclib with adjuvant endocrine therapy in early breast cancer (AFT-05) [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 P4-10-01.

Abstract Introduction: Breast cancer treatments can impair fertility via direct gonadotoxicity (chemotherapy) as well as by introducing delays in childbearing that allow natural ovarian aging. Guidelines strongly recommend fertility counseling and consideration of fertility preservation techniques for premenopausal women who have not completed their desired childbearing at the time of cancer diagnosis. Prior studies have identified high rates of fertility concern but relatively low rates of fertility counseling and use of fertility preservation techniques. We sought to investigate rates of fertility counseling, use of fertility preservation techniques, and how fertility concerns impact cancer treatment decisions in a modern cohort of patients with breast cancer at a large academic medical center in the United States. Methods: All patients seen at Mayo Clinic Rochester with a new diagnosis (within the year prior) of stage 0-4 breast cancer were invited (by mail or in person) to participate in the Mayo Clinic Breast Registry. After informed consent, participants were asked to complete a baseline survey and annual follow-up surveys. On baseline and one-year surveys, patients were queried about desire for future children and fertility concerns. Nurse chart abstraction was used to collect information about tumor subtype, stage, and treatments received. We examined survey data from women diagnosed under the age of 50 who expressed an interest in having future biological children on either the baseline or year 1 survey between February 2015 and October 2020. Descriptive statistics were used to summarize the degree of fertility concern in this population, the impact of that concern on cancer treatment decisions, and steps taken to preserve fertility. Results: Between February 2015 and October 2020, 865 women under age 50 at diagnosis consented to the registry. Of these women, 627 completed a baseline and/or 1-year survey and 100 answered either “yes” or “unsure” to the question: “At the present time, do you wish to have any more biological children in the future?” on one or both surveys. Among the 100 women expressing interest in future child-bearing, 92% were white, 27% had node-positive and one had distant metastatic disease at diagnosis. The age at diagnosis ranged from 19 to 49 years, with a mean age of 33.8 years. Of the 75 who reported a desire for future children at baseline, 28% felt “somewhat concerned” about their future fertility and 40% felt “very concerned.” Of the 70 who reported a desire for future children on the year 1 survey, 17% felt “somewhat concerned” and 59% felt “very concerned.” For those “very concerned” about future fertility at year 1, 65% reported that this concern had a major impact on their treatment decisions. Often, that treatment modification entailed using endocrine therapy for less than 5 years; 52% of those who specified the type of treatment modification they had made indicated this option. Of note, six women who reported no desire for future biological children at baseline were “unsure” at year 1. At year 1, 93% of women recalled a discussion about fertility with their doctor prior to starting treatment, and 49% had taken steps to preserve fertility (32.5% with embryo cryopreservation, 20% with oocyte cryopreservation and 65% with a GnRH agonist; some selected multiple options). Conclusion: We found a reassuringly high rate of patient-reported fertility counseling and use of reproductive endocrinology technologies to preserve fertility in women who reported a desire for additional children at or soon after diagnosis with breast cancer. Consistent with prior studies, fertility concerns frequently impacted breast cancer treatment decisions. It is important to err on the side of inclusivity when providing fertility counseling because desire for fertility can change over time. Citation Format: Samantha Mannion, Alexandra Higgins, Elizabeth A Stewart, Zaraq Khan, Chandra Shenoy, Nicole Larson, Hazel B Nichols, H Irene Su, Ann H Partridge, Fergus J Couch, Janet E Olson, Kathryn Ruddy. Prevalence and impact of fertility concerns in young women with breast cancer [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 P4-11-02.